A cellulosic permeable battery separator comprises a cellulosic substrate thoroughly impregnated with a resin compsn. comprising a resole of no. av. M. W. in range 130 to 300 and an aldehyde: phenol molar ratio of 1.94 to 2.45 and an anti-migratory agent chosen from ethylene glycol, glycerol and sorbitol, the wt. ratio of resole to antimigratory agent being in the range 100:7 to 100:33 and the resole having been advanced to an infusible state.    Pref. the wt. ratio of resole to cellulose substrate is between 1:4 and 1:1. The battery separators have improved oxidation resistance and resistance to acid degradation.
The battery comprises a light metal anode, a fluorinated graphite cathode and an electrolyte dissolved in a Lewis base -type org. solvent. The cathode is surface plated with Cr to give a current collector. The battery storage characteristics are highly improved. In an example, a battery was assembled in a polyethylene case by using a cathode prepd. by pressing a 10:0.5:1.5 mixt. of fluorinated graphite, acetylene black, and a propylene-tetrafluoreoetylene polymer on a Cr-plated Ni screen, an anode prepd. by pressing a Ni screen into a Li sheet, a polypropylene separator, and a 1m LiBF4 - gamma-butyrolactone electrolyte. On storage at 70 degrees for 3 months, the battery showed no decrease in terminal voltage. In contrast, a significant drop in the battery potential on storage for 3 months at 70 degrees was observed when cathode was unplated Ni-screen current collector was used.
A slurry of active C with hydrophic surface, fluorocarbon resin, and ether solvent is coated on an electrode support contg. appropriate catalyst; and fluorocarbon resin dispersion is coated over these layer to give gas diffusion electelctrodes. The coatings prevent leakage of the electrolyte through the electrode without lowering the gas permeability of the electrode. The electrodes are useful in fuel cells, metal-air type batteries, etc.
The separators for storage batteries are prepd. by forming discontinuous ribs of acid- and oxidn-resistant thermoplastic resins on flexible porous sheets of acid- and oxidn-resistant synthetic resin. The use of these separators improves the capacity, discharge voltage, and service lifetime of the battery.    For example, molten polyethylene resin (180 degrees C) was dropped intermittently through a series of linearly arranged noxxles with a pitch distance 14 mm on a moving, porous (pore dia. 0.4 mu) sheet to form spot ribs. The capacity, discharge voltage, and service lifetime of storage batteries prepd. using these separators were improved by factors of 1.4, 1.9, and 1.5, resp., over those of the conventional batteries.
Noble metal catalysts are deposited on sintered Ni-base porous substrates, the substrates are impregnated with a mixt. of a metal phthalocyanine and fluorocarbon polymer emulsion, and heat treated at a temp. near the m.pt. of the fluorocarbon resin to give gas-diffusion type electrodes. The electrodes have excellent catalytic activity even when small amt. of noble metals are used, and they are useful as air battery electrodes. For example, active C 10 and Ni carbonyl powder 90 pts. were sintered to give 0.9-mm thick porous substrate which was immersed in aq. Pd chloride soln. to deposit 1 mg Pd/cm2. The Pd-deposited substrate was immersed in a mixt. contg. Co phthalocyanine 10 and 10% PTFE emulsion 90 pts, the substrate was heat treated at is approx. 330 degrees C and a porous fluorocarbon polymer sheet was laminated on the air-side of the electrode. The air-battery prepd. using 2 of the gas diffusion electrode plates, a porous sintered Fe electrode, 2 Ni screen electrodes for charging of the battery, and KOH electrolyte exhibited excellent discharge characteristics.
An elemental silicon component doped to provide a conductivity of greater than 102 (ohm-cm) -1 is bonded to a metallic component by electroplating the silicon surface with an adherent film of Ni, Cu, Sn, Al, Zn, Ag, Pd, Pt or Au, providing a pool of electrically conductive epoxy resin in contact with both the plated layer and the metal component, and solidifying the resin. In a particular embodiment the silicon component is releasably secured to the metal component by providing the former with a recess into which the latter is inserted and in which the pool is formed. The process is used to mount silicon electrodes on iron or copper conductors for use in electrolytic cells. Also to facilitate the assembly of structural components of silicon into containers and baffles.
A lead acid battery, esp. for electrically propelled vehicles, comprises a battery casing of plastics, esp. moulded thermoplastics, more part. polypropyleme or polyethylene, subdivided into a number of compartments or cells covered at the top with a lid pref. of the same material; each cell contains a stack of positive and negative battery plates the number of positive plates pref. exceeding the number of negative plates by one, e.g., six and five respectively; each positive plate is enclose in a porous layer of polyester material, esp. a non-woven sintered mat of perylene. The lid is pref. integrally welded to the casing and forms a water-filling trough communicating with each cell. The cells pref. contain an aq. soln. of sulphuric acid contg. 1% potassium sulphate. The initial energy output per lb. is higher than that of the conventional battery. The battery is lighter.
Electrically conducting, non-porous polyalkene compsn, esp. for prodn. of bipolar plates or anodes for electrochemical cells, consists of a homogeneous mixt. of (I) 100 pts. wt. of an ethylene/propylene copolymer contg. at least 20, esp. 20-35 mole % ethylene, and (II) at least 30, esp. 90-100 pts. wt. finely divided conducting carbon. The compsn. has very low resistance, homogeneous electrical properties, good mechanical properties and is easily converted to thin impermeable membranes. It is chemically inert, thus being non-toxic relative to fuel cell catalysts.
Anodes for Hg-cathode electrolytic cells in which the short-circuit current between anode and cathode is reduced at any given impressed voltage without preventing passage of electrolysing current under normal operating conditions comprise an anodically conducting oxidic coating with a porous outer layer of C1-resistant polymer covering and bonded to the oxide. The anodes are made by (a) forming a Pt-gp. metal oxide on the anode and (b) applying a coating of polyvinylidene fluoride or low molecular wt. PTFE by either (i) heating the coated anode to 250 degrees C., spraying on molten polymer and cooling or (ii) applying the polymer in a liq. vehicle, removing the vehicle by evapn. and heating to about 250 degrees C. to melt the polymer and cooling. In an exemplary cell, conditions producing a short circuit current of 3A/cm length of anode strip with a polymer coated anode produced a 10-15A current with an uncoated anode.
Electro coating a cathode with a polymeric tertiary aminoalkanol ester of a polymeric carboxylic acid (I) and a pigment from a bath contg. them along with a dispersion stabilizer which is an acid at least as strong as acetic acid, the improvement comprises supplementing the solids content of the bath with a compsn. (II) comprising an intimitate mixt. of (a) pigment having an av. particle size 2 mu for pigments of density of 3.5, 5 mu for pigments of density &lt;3.5, the particle size distribution being such that 5 wt. % has a particle size of 10 mu and the pigment remains particulate when the electro deposit is cured, (b) polymeric tert. aminoalkanol ester, at concn. (in (II)) greater than that in the bath, and the wt. ratio of ester to pigment being the same as the wt. ratio of ester and pigment in deposited coating and 1.5:1 and 70-80 wt. % of the ester to pigment in the bath when the potential is 25-250 volts, the concn. of ionizing acid in (II) is below that in the bath. Prevents the deposition of chalky, resin-starved appearing films.
In a galvanic cell having an alkaline electrolyte within a container and including 1 surface wettable by the electrolyte, (part of) which is not desired to be wetted, the surface(portion) not to be wetted consists of a fatty polyamide having an amine no. &gt;10 and opt. &gt;1 modifier or extender to prevent creeping of the electrolyte over or through the surface.
An electrochemical cell comprising an alkali metal anode, a cathode material of Au, C or an intercalation cpd. (C4F)n, where n is a large indefinite no., an electrolyte comprising an inorganic solvent from POC13, SOCI2 and/or SO2C12 and a solute dissolvent in it, has a Ti or Ti alloy casing contg. all cell components. The cathode material catalytically decomposes the solvent during operation, the solvent being used as the oxidising cathode cpd. A lightweight, rechargeable Li or other alkali metal cell, operable at ambient temp. and press. is provided.
A dry cell comprising a cathode mixture, a zinc anode, and a layer as a paste by dissolving in an electrolyte, the layer being produced by laminating two polyvinyl alcohol films including at least one material of good water absorption water retention and polyvinyl alcohol films including at least one material of good water absorption and retention and also swelling and binding property. The layer is disposed between the cathode mixture and the zinc anode.
Dry cell comprises a cathod mixt., a zinc anode, and a polyvinyl alcohol film produced by dissolving material in an electrolyte within the dry cell to form a paste, the material having good water absorption and retention props., swelling property and binding property. The film is disposed between the cathod mixt. and the zinc anode.
An alk. battery is fabricated with a packing material based on chlorosuphonated polyethylene (I), either in the liq. form or as a hardened film. Leakproof batteries can be fabricated. In an example, a packing material was obtained by mxing I (av. mol. wt. 30,000, Cl 45%, S 2%) 40.0, octadecylamine 10.k, Ni dibutyldithlocarbamate 2.5, lithopone 8.0, PhMe 19.0, and MeCOET 20.0%. When this material was applied between the insulation packing material and the metal battery case and dried, the battery showed good leakproof characteristics (1 defective battery out of 100 after 12 months at relative humidity 90%). In contrast batteries prepd. in the conventional means using an epoxy sealant showed 10 and 34% failure after 9 and 12 months, reps. 26.
The electrode is useful for air-Fe and Ni-Fe alk. batteries. In an example, 1 kg electrolytic Fe (-325 mesh) was mixed with 0.01N H2SO4 (20 degrees) and kept in dry air for 15 min at 100 degrees to effect direct (80%) oxidn. of the powder. The powder was reduced by heating for 30 min at 300 degrees in H and sintered by heating for is approx. 5 min at 950 degrees in H. A battery was assembled by using this electrode (50 x 60 x 1 mm, porosity 65%), a Ni electrode with discharge capacity is approx. 6 A-hr, a polypropylene unwoven fabric separator and a 30% KOH electrolyte.    The battery was charged-discharged with 10 mA/cm2 repeatedly, using a charging time 1.3 times that of the discharging time. This battery showed a much higher discharge capacity and superior lifetime compared to a battery using an electrode prepd. with com. Fe powder.
Electrodeposition of Zn (dissolved in the electrolyte) on the anode during the charging of the battery is prevented, to increase the service lifetime of the battery. In an example,a Ni screen was coated with a ZnO paste and electrolytically reduced to give a porous Zn anode. A battery was assembled by using this anode, an O-diffusion cathode, an auxiliary Ni-screen charging electrode placed between the anode and the cathode, and cellulose separators positioned between the electrodes. The battery was filled with a satd. Mn(PH)2 soln. prepd. by adding aq. MnCl2 to 7N KOH contg. poly(N,N-dimethyldiallylammonium chloride 1%. When charged at 25 mA/cm2, the formation of Zn was not obsd. at 1.jo V. at 1.43 V, Zn deposition occurred, but on increasing the voltage to is approx. 1-5 V, H evolution became vigorous and the deposition of Zn was kept to a min. In contrast, a conventional battery contg. a ZnO-satd. 7N KOH soln. shorted out owing to the function of dendritic Zn.
In a H2O-activated battery, a thin film of hydrophilic resin, such as poly(vinyl alc.) or Me cellulose, is deposited on the cathode surface. The coating firmed on a PbO2 cathode surface is smooth, the granules are bonded together tightly, and on the addn. of the activation electrolyte, PbO2 particles do not fall off. Hence short-circuiting, resulting from contacts of cathodic and anodic particles, can be avoided.
The battery comprises a light metal anode, a fluorinated graphite cathode contg. a sparingly sol. metal fluoride, and an org. electrolyte. The reactivity of the cathode surface is thus increased, and the drop in the discharge voltage on high-temp. storage is prevented. In an example, a 10:0.-7:1:1 mixt. of fluorinated graphite, acetylene black electro-conductor, PTFE binder, and CdF2 was pressed against a Ni screen to give a cathode (35 x 35 x 1 mm, 2 g). A battery was then assembled by using this cathode, an anode prepd. by pressing a Ni screen against a Li sheet, A 1M LiClO4-propylene carbonate electrolyte and an unwoven polypropylene fabric separator; a lamination of 3 cathode plates and 4 anode ones being used per battery. The battery showed no change in terminal voltage when discharged through a 100-mA load even after storage at 45 degrees C for 1 year. In contrast, a conventional battery contg. cathodes without CdF2 showed a 50-mV drop after 6 months and a 200-mV drop in terminal voltage after
Amalgamated zinc powder is dispersed in gel electrolyte prepd. by adding ZnO and alkali soln. to an aq. Cm-cellulosesoln. to give zinc anodic mix for alk. batteries. The mix reduces the gas generation and the amt. of electrolyte leakage. In an example, CM-cellulose 1 was dissolved in 10 pts of water, and 45% KOH 54 and ZnO 4 pts were added to the CM cellulose soln. to give a gel electrolyte in which amalgamated Zn 70 pts was dispersed. The gas generation in the alk. battery prepd. with these anode mix was less than that in a conventional alk. battery.
Zn alk. batteries have Zn anodes whose heights are greater than those of the cathodes so that the top section of the anodes are well abovethe electrolyte surface; the surfaces of Zn anodes being placed in contact with liq. - impregnated mats. This battery design prevents the dendritic growth of Zn during charging of the batteries and improves their service lifetime.
The separators are prepd. by adhering porous cryst. polypropylene films on both sides of a polypropylene non-woven cloth by the hot-spot melting method. The cloth improves the strength of the separator, and the films prevent the accumulation of the gases produced at electrodes. In an example, porous, surfactant-treated cryst. polypropylene films (thickness 25, pore diam. 0.1 mu, porosity 35%) were adhered on both sides of a 50-mu thick polypropylene non-woven cloth by te hot-spot (0.3-mm diam., 3-mm interval) melting method. The Ni-Cd batteries contg. this separator showed considerably better discharge characteristics than the conventional ones.
The conventional alk.-battery anodic plate mfg. comprising coating to a porous metal substrate with Cd-base active substance paste, drying of the paste, pressing of the dried material, and electrochem, treatment is modified by an addnl. step of immersing the electrode material in an aq. org.-binder soln. after drying or the electrohem. treatment. The modification improves the mech. strength of the anodic plate. Thus, CdO 75, poly(vinyl alc.) 3, and ethylene glycol 22 parts were kneaded well to give an active-substance paste, the paste was coated on porous Ni-plated steel plate and dried 2 hr at 100 degrees. The coated plate was immersed in aq. 3% poly(vinyl alc.) for 5 min, the plate was dried in 70 degrees compressed, and electrochem. treated to give an alk-battery anodic plate of better mech. stability than the conventionally prepd. anodes.
Cd-base active substance, a binder soln., a thermoplastic resin, and an elec. conductive powder are mixed well to give anode active mass which is coated on an elec. conductive porous substrate, dried, and hot pressed to give alk.-battery anodes. The binding of the active mass with the substrate is improved, and the loss of the active mass during the battery mfr. is reduced.
A lead accumulator with 2 cells with a H2SO4 electrolyte has a bipolar electrode with an electrically conducting impermeable metal plate of Ti or a Ti alloy on one side and Zr or a Zr alloy on the other side, which forms a separating wall between 2 adjacent cells, with a support for the active PbO2 compsn. of the positive electrode of one cell on one side and a support for active Pb compsn. of the negative electrode of the adjacent cell on the other side. These surfaces can be joined directly, pref. by a metallurgical bond formed by hot rolling or explosion plating; or be sped. by another metal, pref. with a higher electric conductivity than the Ti (alloy) and/or Zr (allow), esp. Cu, Al or Fe. There pref. is a Pb layer between the first surface and the active PbO2 compsn. The support has a perforated structure. This arrangement allows the construction of lead accumulators of the truly bipolar type.
The installation consists of separate automatic components feed mechanism and a thermal fusion platform. The microporous plastics plates are fed from one hopper and are separated from each other before they are aligned with glass fibre plates fed from another hopper, with its own separator. After alignment the two plates are advanced to a fusing platform. The plastics separators (1) are fed from a hopper on to the chain conveyor (3) and are separated from each other by mechanism (2). The hopper (4) feeds glass fibre plates, which are separated by pins on the guide platforms (5). The chain conveyor (3) grabs the two plates simultaneously and feeds them together to the thermal fusing mechanism (8). The installation is driven by a single motor with reduction gear (6).
A mould is provided for moulding a generally rectangular plastic case of an electric storage battery with integral cross partitions between the cells. Teh opposed ends surfaces of the cavity and core mould sections are outwardly curved so that the moulded end walls will either remain slightly bowed out or at least will not bow inwardly on cooling and shrinkage. Pref. plastic matl. is polypropylene. Difficulty in assembling the plates into the container is avoided. Prodn. speed can be increased, since the normal tendency for the end walls to become increasingly distorted inwardly at higher prod. rates, is nullified.
Mfr. of a slim, closed-end cylindrical separator for dry batteries, comprises making the separator in one integral operation, using a fibrous paper produced from a viscous soln. of a partially saponified polyvinyl alcohol contg. a surfactant without any further after-treatment such as softening with a surfactant, then the paper is wrapped around a metal bar to which it does not tend to adhere, e.g. stainless steel, to give it its final shape. Process is simpler than conventional process, (in which fully and partially saponified polyvinyl alcohol are used to make the paper) and the paper possesses sufficient strength.
Battery plate retainer or separator has a continuous electrolyte permeable layer of matted electrically insulating and electrolyte resistant fibres contg. no vinder materials, and a second electrolyte permeable layer of electrolyte resistant fibres bound together with a binder, the two layers being attached face to face by a number of selectively spaced attachments so that only portions of the two layers are attached one to the other. The plates are used to retain paste and prevent bridging of metallic deposits between them. The plates are cheap and do not require additional separators, such as resin impregnated ribbed paper inserts.
In an alkaline electrolyte storage battery comprising a pack of alternate nickel anodes and zinc cathodes each cathode comprises a number of perforated metal strip pockets containing zinc and seamed together along their edges, each pocket comprising two meal strips perforated lengthwise along their central region and with their edges in telescoping interlocking arrangement. The ends of each pocket are closed by crimping, while a felt separator is applied across opposite sides of each cathode, an ionic membrane tape is subsequently wrapped around it, and a plastic mesh insulator is applied across opposite sides of each anode. The active material of the cathode may be metallic zine and ZnO, possibly also with small amounts of mercuric oxide and polyvinyl pyrrolidone, while after formation of the cathode plates they may be compressed to hold the active material in close electrical contact with the strips. There is no loss of zinc from the cathode during cycling, giving greatly increased battery life.
Pasted flexible electrode plates are made by (a) making an aq. paste mixt. of (1) electrochemically active material chosen from HgO, MnO2, Zn Cd, Fe, In, Mg, Al and Pb, (2) a water sol. resin binder and (3) a hydrophilic plasticizer to impart flexibility to the finished plate, (b) securing the paste to an electrically-conductive substrate to form the electrode plate and (c) drying the plate at 50-90 degrees F under controlled humidity, esp. 30-70% R. H. Used as anodes in alkaline galvanic cells requiring a cohesive flexible electrode.
A current-producing cell comprises a lithium metal anode, an electrolyte of lithium hexafluoro arsenate dissolved in methyl formate in sufficient amount to render the solution conductive, and a depolarising cathode having as a major constituent Ag Cl, NaF2 CuCl2, CuBr2, MnO2, V2O5 or an oxide of a metal of groups IVB, V, VIB or VIIB. Pref. the electrolyte contains 1 mole of fluoro arsenate per litre, and the cathode consists of 90% V2O5, 9% carbon black and 1% polystyrene. The cell provides a high rate of output over a wide temp. range. Lithium shows good stability in the electrolyte. Anode activity may be moderated by alloying lithium with another metal.
The amt. of resin fraction used is 0.1-2 wt. % of the lead powder. It is desulphurised by alkaline oxyhydrolysis and mixes well with oxidn. inhibitors for lead such as -hydroxy naphthoic acid. The electrical characteristics of the accumulator anodes are good.
Fluoride battery comprises a two compartment cell with a porous partition between the compartments, the cathode compartment contg. CIF5 and an electrolyte dissolved in anhydrous HF into which a metal electrode is plunged, the anode compartment contg. a soln of electrolyte in duhydrous HF into which a lithium based electrode is plunged. Suitable anodes are pure or alloyed Li or an organic matl. impregnated with Li metal. The preferred electrolyte is LiF and the cathode is Pt. The partition is pref: a sintered PTFE. (Teflon RTM). The cell presents an energy density markedly higher than practically any other known cell.
Porous diaphragm for an electrolytic cell is mfd., from several sheets of PTFE contg. a filler, by melting a fluorinated polymer transformable to the molten state, in the juxtaposed edges of these sheets, at a temp. which does not produce decompsn. of the filler material in the sheets; solidifying the fluorinated polymer so as to assemble the sheets together, and finally extracting the filler material from the juxtaposed sheets. Diaphragms of desired shape and dimension can be mfd., esp. suitable for electrolysis cells operating with alkali metal chloride solns.
Industrial lead acid battery, including 1 microporous separator of synthetic plastics, contains in the separator or in the electrolyte an org. cpd (I) that is relatively insol. in the electrolyte and which has radicals, some of which are water-sol. while separator contains a mineral (II) which can absorb (I). (II) is pref. 10 wt. % (w.r.t. the separator) of a silicious matl, and (I) pref. contains a polyoxythylene as water-sol. radical, and is present in an amt. of 1-8 wt. % (cont. the day separator). The device is used for operating escalators, railways and carriages in communications systems. Final voltage after charging is increased compared with batteries using rubber separators.
Self supporting easily deformable sheet of thermoplastics material is extruded and fed between calender rolls each having depressions that are interrupted circumferentially and spaced around the circumference, one of the rolls being warm and having deeper depressions to mould high projections than the other roll which is hot and has a shallow depressions to mould shorter projections. The sheet is transported round at least 20% of the circumference of the roll having the deeper depressions to partially set the calendered sheet. The sheet is removed from the roll having deeper depressions and the side of the sheet with the shorter projections is engaged with a cooling roll afte which the sheet feeds between sizing rolls the roll engaging the higher projections being heated. Used to make sheet for conversion to ribbed battery separator. Provides a sheet having extremely uniform thickness dimensions, which enables use of thinnest possible battery separator commensurate with the necessary separation of the battery plates while providing adequate channels for the escape of gas formed.
An alk. battery is prepd. by charging the anode compartment with 30-40% KOH, CM-cellulose powder (2-8 of the KOH soln., 1-8% of the anode-active materials), and Na polyacrylate powder (2-7 of the KOH soln., 1-7% of the anode-active material) to give a gel-like anode material. These anode materials can be used with alk. batteries employing air O, Ag2O, HgO, or MnO2 cathodes and Zn or Fe anodes. In an example, a Zn-air battery was prepd. by pressing an O-ionizing catalyst on the exterior of a water repellent-treated, hollow C cylinder, wrapping with absorbent paper and a separator, placing in a case serving as the anode, and filling the case with a mixt. of 35% KOH, 7% Zn amalgam 100, CM-cellulose 3, and Na polyacrylate 1-8 parts. The fabrication of the battery was completed in the conventional manner. At 20 degrees, &lt;55-75% humidity, and discharge across a 4-OMEGA resistance, only 2% of the batteries shoed any leakage of the electrolyte after 2000 hr. In contrast, batteries prepd. with &gt;40% KOH electrolyte and lesser amts. of CM-cellulose and Na polyacrylate showed a leakage rate of 24/100, 78/100, and 100/100 after 500, 1600, and 2000 hr, resp.
Grating for accumulator plates is produced by (a) providing a mould made of a material that is resistant to high temps., and has a low dielectric loss, (b) introducing into the mould particles of a synthetic resin that can be sintered (c) subjecting the resin particles to high frequency heating, so that they are sintered, without melting, and (d) removing the grating from the mould. Pref. resin particles are of PVC and mould is of silicone rubber. Gives cheap, rapid prodn. of high quality moulds. Easily adaptable to continuous prodn. of gratings.
Separator leaves for an electrochemical cell, incorporate a felt of mineral or resin fibres fixed to a mesh made of continuous filaments of similar material. Leaves with meshes made of glass or polyprolyene filaments are for use in acidic cells, while leaves with meshes of polyamide or PVC filaments are for alkaline cells. Composite leaves offer greater porosity than simple mat leaves and are of sufficient thickness and strength to act as the structural components of the wound electrodes, thus increasing cell efficiency.
Cell as a cathode formed of a mixt. comprising 40-50 pts. wt. active matl. of an aromatic nitro cpd., 45-50 pts. wt. carbon powder, 5-20 pts. wt. polyethylene powder and 0.1-2 pts. wt. acrylic fibres. Meta-dinitro-benzene, nitrobenzene and 1,3,5 trinitro-benzene are used s the aromatic nitro cpd. A magnesium plate is used as the anode and a liq. ammonia soln. contg. potassium thiocyanate is used as the electrolyte.
Hybrid electrode for metal/air cells comprises on the electrolyte side a hydrophilic layer of Ni for separation of the oxygen, on the gas side a hydrophobic layer of plastic matl. and between the two layers, for dissolving the oxygen a hydrophobic layer of catalytic carbon enclosing a metallic structure which is rigidly in contact with the Ni layer on the electrolyte side and, on the gas side penetrates beyond the carbon into the plastic layer. Improved mechanical stability and strength. The electrode can withstand more readily the cyclic changes due to dissoln. of oxygen and sepn. of oxygen.
Battery cap has a central channel which communicates with the cap interior and which contains a filter of which one surface communicates with the atmosphere and another surface communicates with the channel. The filter is made of porous matl., pref. polyvinyl fluoride, polyethylene or polypropylene, compressed at the outer edges to make it non-porous, while the central area remains porous to escaping battery gases. The filter is made of or has added to it flame-retardant matl., and has low heat conductivity.
A battery separator comprises a non-woven fabric of 40-50 wt. % viscose rayon fibres (A), 30-50 wt. % sparingly water sol. PVA fibres, (B) and 10-20 wt. % water-soluble PVA fibres, (C), (A) and (B) being bonded together by (C). Alkaline ,n and Leclanche cells incorporating such a separator are also new. (A) has high mechanical strength and chemical stability, (B) increases mechanical strength and prevents excessive swelling or shrinkage, (C) improves wet tenacity tearing and surface unevenness are prevented so mfr. is easir.
The battery of improved charge-discharge characteristics comprises a MnO2 cathode, an aq. alk. electrolyte, and an anode obtd. by adding an alk. earth hydroxide to Zn. In an example, flaky graphite 7, acetylene black 3, and a paraffin suspension (40% solids) 0.05 pts. were mixed, MnO2 40 and a small amt. of H2O were added, and following mixing, the paste was moulded into a tubular cathode. The cathode was placed in a can, and a separator placed in its hollow centre was impregnated with an alk. soln. An anode paste obtd. by adding 40% KOH to a mixt. of Zn amalgam powder (30-150 mesh) 60, Ca(OH)2 10, and CM-cellulose 1 pt. was then added to the hollow centre. The battery was assembled in the conventional manner. This battery showed improved continuous discharge props. over many charge-discharge cycles when compared to conventional alk. Mn batteries prepd. without using the alk. earth hydroxide.
The battery comprises a MnO2 cathoe, an aq. alk. electrolyte, a Zn-contg. anode, and a layer of an alk. earth hydroxide between the anode and that cathode. In an example, a mixt. of MnO2 40, graphite flakes 7, acetylene black 3 pts. and a small amt. of H2O, was moulded into a tubular cathode. The cathode was placed in a can, and acup-shaped separator placed in the hollow centre space of the cathode was impregnated with 40% KOH. Nonwoven nylon was coated with a paste consisting of Ca(OH)2 10, Na polyacrylate 0.5, and H2O 20%, and the paste layer was covered with a 2nd nonwoven nylon film, cut and placed in contact with the separator. Zn amalgam powder (30-150 mesh) 60 and CM-cellulose 1 were placed in the hollow centre, and alk. electrolyte 30 pts. was added wtih stirring to form the anode. Part of the electrolyte in the anode penetrated the adjacent film layer to make it ionically conductive. This battery showed superior continuous discharge characteristics over many charge-discharge cycles, compared to a conventional battery not having the alk. earth hydroxide layer.
The separator with O air permeability is obtd. by coating 1 sides of a Na polyacrylate- or Na alginate impregnated fibrous substrate with a starch-based paste. In an example, kraft paper was coated with an aq. soln (n000cP) of Na alginate (0.2g/100cm2) to give a 0.11 mm. thick separator with air permeability &gt;60 min (time required for 100ml. of air at 50g/cm2 pressure to pass through a 10cm2 area of the separator). When assembled into a dry cell after being coated with a natural starch paste, the cell showed, immediately after fabrication, an open-circuit voltage 1.69V, a short-circuit voltage 4.0V and the time required to reach a terminal voltage 0.85 V across a 10 omega resistance 200 min. The corresponding values after 3-month storage at 45 degrees were 1.61 V, 3.2V and 165 min.
The battery of improved capacity and shelf life has a mol sieve in 1 battery components selected from the electrolyte, the cathode active material, and the separator. Battery anodes consist of alkali metals, and possible cathode active materials are MoO3 and CuF2. In an example, a button-type batteyr was assembled from stamped Ni-plated steel half-shells and a polypropylene packing material. The cathode consisting of a MoO3 active material 75, a graphite conductive material 22.5, and a mol. sieve 2.5% was sepd. from an anode obtd. by pressing Li on a 30-mesh Ni screen, with a separator. The latter comprised a 0.05mm nonwoven polypropylene sheet coatd (0.005mm) on both sides with a paste contg. a 50:50 wt. ratio mixt. of 1M LiClO4 in propylene carbonate and 300-mesh mol. sieve, covered again with a 0.05mm. nonwoven polypropylene sheet. The battery was assembled in Ar using a 1M LiC104-propylene carbonate electrolyte contg. 300-mesh mol. sieve 5%. This battery showed a 15% improvement in discharge capacity over a conventional battery not using the mol. sieve.
The lighweight and durable battery is fabricated with composite bipolar electrodes obtd. by bonding a metallic film with a conductive Pb(alloy) film on one side and a conductive C sheet on the other side, and with cathode-active material in contact with one surface and an anode-active material in contact with the other surface of the electrode. In an example, C powder (350 mesh) 7 was mixed with 30% benzene soln. of polystyrene 3 pts. and rolled into a 0.2mm sheet. This film was 1/9. the wt. of conventionally used Pb films. A thin Pb film ws electroplated with Au in a cyanide bath to deposit nmu-thick film. The C sheet was bonded to the Au-plated Pb film with a resin binder. A cathode-active material was coated on the PB-film side and an anode-active material on the conductive C sheet. A battery prepd. with this electrode withstood several tens charge-discharge cycles and its power output/unit wt. was is approx. 15% higher than that of a battery using a 0.2mm-thick Pb conductive film.
The lightweight battery of long service life comprises bipolar-electrode plates obtd. by coating one side of a Ti (alloy) plate with a cathode-active mass and the other side with an anode-active layer, the latter being sepd. from the plate by an electroconductive C sheet. Opt. a Au film is deposited on teh Ti(alloy) sheet before the cathode-active mass. In an example, a C sheet (0.2mm) prepd. by applying a roller to a mixt. of -350 mesh C powder 7 and 30% polystyrene in benzene soln. 3 pts. was applied on one surface of a thin Ti sheet and coated with an anode-active mass. A cathode-active mass was coated on the other surface to give a bipolar electrode. An electrolyte was placed between an assembly of these electrodes. The battery withstood &gt; 100 charge-discharge cycles and its power output/unit wt. was increased 15% over a battery using Pb as the electro-conductive plate.
The chem. attack of Zn anode is inhibited, gas evolution is reduced, and battery performance characteristics are improved by addn. of an aminonaphthalenesulphonic aid or its deriv. to the electrolyte. The use of the conventionally-used toxic Zn amalgam can thus be avoided. In an example, a mixt. of MnO2 and graphite was moistened with 5% KOH and packed into a can (cathode). The central hollow portion was filled with a paste obtd. by blending Zn powder and CM-cellulose with 30% NaOH contg. 0.01% Z-aminonaphthalene-6-sulphonic acid; the depolariser and the Zn paste being sepd. with a separator. The battery assembled in the conventional manner showed, immediately following fabrication, an open-circuit voltage 1.56V and a short-circuit current 12.0A. The resp. values on 6-month storage at 45 degrees C were 1.52V and 8.0A. The terminal voltage dropped to 0.9V after 8.0 hr. continuous discharge across a 4-omega resistance.
The battery is constructed by using an anode plate obtd. by sandwiching a paste contg. powdered Zn or ZnO and Zn between 2 liq.-absorbent sheets, placing an electroconductive screen in contact with the assembly, forming , and removing the screen. The anode plate is pressed against a divder plate with Ag cathode sintered on it other surface, and placed in the batteyr case. The use of an expensive Ag screen in the battery cathode is not required, and los of the active mass is prevented by wrapping the anode plate in liq-retentive vinal-fibre paper.
The battery uses an F--contg. electrolyte to prevent erosion of the Zn electrode and deactivation resulting from Zn-oxide deposition, causing loss of discharge capacity. In an example, an air-Zn alk. storage battery was prepd. by using Ni-screen air electrode, an anode comprising a Ag screen coated with a paste contg. ZnO powder 100, polyamide fibre (2-3mm) 0.6, and 25% aq. poly(vinyl alcohol) 40 pts. and separators. When chared with 7N KOH contg. 2g. KF/1. a battery of nimal discharge capacity 3 A-hr. showed is approx. 50% redn. in the discharge capacity after 100 charge (140%, 0.4 A)-discharge cycle. A conventional battery not contg. F- showed a &lt;20% discharge capacity after 60 cycles.
A Zn alk. storage battery used ZnF2 as the anode-active material.    The solubility of the Zn electrode is lowered without reducing its efficiency. In an example, a Ni-Zn alk. battery was constructed by using sintered Ni cathodes and anodes comprising a Ag grid coated with a paste contg ZnF2 powder 100, polyamide fibre (2-3mm) 0.6, and 25% aq. poly(vinyl alcohol) 40 pts. Two Zn electrode plates were wrapped in a cellulose cloth, cellophane paper, and a separator material. Five cathodes and 4 anodes were placed alternately in a polystyrene battery case and the assembly was fileld with 7N KOH. When discharged and charged to 140% of capacity with 0.4A, the battery had a 60% discharge capcity after 200 charge-discharge cycles. In contrast, a battery using ZnO- instead of ZnF2-anode material showed a rapid decline in discharge capacity (20% after 60 cycles).
The battery employs a ZnF2 anode-active material and a F--contg. electrolyte. The battery life is extended by preventing the drop in battery capacity over many charge-discharge cycles by simultaneously lowering the Zn-electrode solubility and preventing Zn-electrode deactivation, resulting from Zn-oxide formation on rapid discharge. In an example, a Ni-Zn alk. battery was constructed by using sintered Ni cathodes and anodes comprising a Ag grid coated with a paste contg. ZnF2 powder 100, polyamide fibre (2-3mm) 0.6, and 25% aq. poly(vinyl alcohol) 40 pts. Two Zn electrode plates were wrapped in a cellulose cloth, cellophane paper, and a separator material. Five cathodes and 4 anodes were placed alternately in a polystyrene battery case and case was filled with 7N KOH contg. 1 mole KF/1. When discharged and charged to 140% of capacity with 0.4A, the battery had a &gt;100% discharge capacity after 200 charge-discharge cycles. In contrast, a battery contg. only KOH electrolyte had 60% discharge capacity after 200 cycles.
Securing a metal mesh to a sheet of gas porous hydrophobic synthetic resin material, consists of coating the side of the mesh with weldable synthetic resin and heating it in contact with the sheet so that the weldable resin melts and keys into the pores of the sheet. A gas electrode is made by coating the other side of the mesh with catalyst material, after it has been secured to the sheet. The mesh is e.g. of expanded Ni and the resin substrate pref. of PTFE. Used for mfg. metal-air battery electrodes.
Mfr. of tubular sheaths for storage battery (tubular) electrodes comprises passing the material for the intended sheaths in form of a continuous web over a freely suspended mandrel, shaping the sheaths on the mandrel, and cutting to desired length. Sheaths of any cross-section may be mfrd. The sheaths may be formed formed from a web made up of braided material which is impregnated with a hardenable material e.g. a soluble resin or other plastic material to impart the prod. dimensional stability after shaping. The mandrel may be maintained in position by magnets, and also stopped by appln. of a magnetic field. It may be constructed of 1 or more components of magnetisable material, at least 1 component being enveloped in non-magnetisable material. The former may be steel, the latter Cu, Al or an alloy from these metals.
Continuous mfr. of tubular sheaths for storage battery electrodes having any pre-determined cross-section, and made of a first, fibrous material and a second, dimensionally stabilising material, comprises contacting the 2 materials, applying them to a first section of a mandrel, as a pre-treatment enabling the sheath to be formed subsequently; and imparting to the sheath the desired cross-section on a 2nd, differently shaped, section of the mandrel; and treating so that this cross-section is maintained. The fibrous material may be glass- or polymeric (e.g. vinyl, polyester) fibres. The dimensionally stabilising material may be a perforated plastics film.
In filling electrolyte-permeable porous casing around the lead tubes of lead accumulator tube plates by forcing pasty active compsn., which contains a mixt. of Pb oxide, H2SO4 and excess H2O to reduce the viscosity, into the casing, the casing is first prepd. with a material (I), which wholly or partly seals and/or covers the pores, and then is filled with the active compsn. and made electrolyte-permeable again directly or indirectly. (I) can consist of a film, e.g. of CMC or fitted cover plates of elastic material, e.g. sponge rubber or silicone rubber. Material loss due to excessive liquid outflow is avoided and it is possible to fill long tubes completely, without the addn. of a flow aid to prevent premature setting of the plate.
A planar battery comprises superposed electricity-generating components comprising (a) coextensive planar anode (Zn) and cathode (C and MnO2), at least one, pref. both, including a conductive thermoplastic layer, (b) a planar separator intermediate and coextensive with the electrodes, having a central aq. -electrolyte-permeable portion and a marginal portion, (c) an aq. electrolyte (ZnCl2 and/or NH4Cl) in the central portion contacting electrode surfaces, (d) a non-conducting adhesive layer securing the marginal surfaces of the separator to adjacent surfaces, and (e) an insulator layer intermediate the adjacent marginal surfaces of anode and cathode that is thermostable at the softening temp. of the thermoplastic layer.
In a covered solar cell, comprising a wafer of Si semi-conductor matl. having an electrical contact on its surface with an antireflective coating on the surface of the wafer and contact and a transparent cover glass over the wafer to dissipate heat and minimise bombardment damage, a transparent plastic film of a interpolymer of tetrafluoroethylene and hexafluoropropylene, 1-2 mils thick, is bonded to the cover glass and antireflective coating to bind them together. An antireflection coating may be provided on the cover glass. The solar cell is for space use. The amt. of blue light impinging on the cell is increased by the absence of UV filters conventionally used to protect the epoxy bond cement, increasing cell efficiency.
In the manu. of an anode unit for an electrolytic cell with a current input metal bar passing through an aperture in the side wall of the cell bottom, the improvement comprises sealing the joint between metal bar and lead anode base by applying a heat shrinkable thermoplastic sleeve rendered thermosetting by irradiation. Irradiation is carried out prior to pouring molten lead around the metal bar to form the anode base. Graphite anodes extend upwards from base. The sleeve prevents corrosion of the bar at the interface with the lead base near the aperture in the side wall at the cell bottom.
This opening is fitted with guiding grippers hinged on a suspension frame. The mandrel is rigidly connected to the chain and linked to the pusher by means of forks, brackets and templates. In this way the amount of heat-sealing insulation is reduced. The pusher moves towards the mandrel so that the packet encloses the articles as it enters the magazine and introduces it to the calibrating opening. As the pusher moves so does the template, thus engaging with the roller pushing up the arm and the form to make contact with the outer surface of the mandrel, fixing the frame which has opening, and the guiding clamps along the axis of the mandrel. The sections of the 'Rubin-1' battery for the negative side re drawn from opening, and the template engages with the roller; this causes bracket to turn on pivot on lifting on the top of which are grippers. The section of the battery enters the packet. Another parallel rod with a second gripper at the top then proceeds to act on the positive side of the battery plates, so that it enters the packet and the mandrel, followed by the switching wires. Once assembled, all movable part return to their starting points and the cycles is repeated.
Terminals and e.g. electrolyte level probe are moulded into the walls of a thermoplastic battery box to which the lid is later to be welded. A punch is entered into the moulding gaps from the interior of the mould cavity and is sealingly abutted by an end face of the terminal or probe which is entered from the outside. The punch is left in place during casting and removed when the box is taken out of the mould. For boxes e.g. of polypropylen or ethylene and propylene copolymer, to which lids of the same material can successfully be welded, but where it is difficult to fix the metal terminals and probe so that they remain sealed.
Separators, spacing elements, etc. fr use in batteries and esp. Pb accumulators such that they comprise microporous structures formed from organic high polymer fibres such as are obtd. from satd. polyesters, polyacrylonitrile, or pref. phenolic resin, which are impregnated with 1-50 wt % organopolysiloxane and cured. The parts have better acid resistance and sheet strength than conventional separators. Can be thinner than previously possible, giving Pb accumulators of more compact dimensions and retain efficiency longer, giving better resistance to repeated charging and discharging.
A separator for a battery comprises a porous sheet and a micro-porous film joined by laminating, sticking or heat setting. The porous sheet is produced by stretching an embossed synthetic resin sheet in a biaxial direction, and the micro-porous film is produced by coating a plate-like or porous body with a uniform synthetic resin soln. consisting of synthetic resin solvent and non-solvent from the synthetic resin layer coated on the plate-like of porous body.
A solid-electrolyte thermal battery of long shelf life contains 5 successively arranged solid layers, a cathode layer, a AgI layer, a cpd . x layer (x=AG2S, RbI, KI, Me4NI, KCN and Ag3PO4), a AgI-x mix layer, and an anode layer. In an example a disc-shaped poly(tetrafluoroethylene) container was provided successively with a cathode lead wire, a cathode current carrier, a cathode layer, (I-graphite RbAg4I5 7:2:1 wt. ratio), A AgI layer which prevents diffusion of cathode-active material to the anode, a RbI layer, a mixed AgI-rbI layer, an anode (Ag-RbAg4I5 8:2 wt. ratio) as anode current carrier, and an anode lead wire. The battery was activated by heating to 200 degrees C. The discharge characteristics of this battery immediately after its fabrication and 3 yrs later were identical.
A solid electrolyte thermal battery of long shelf life contains a cathode layer, a AgI layer, a AgI-RbI mix layer and an anode layer. The AgI and RbI are mixed in proportions to give a max. sp. cond. In an example a disc-shaped poly(tetrafluoroethylene) container was provided successively with a cathode lead wire, a cathode current collector, a cathode layer, (I-graphite- RbAg4I5, 7:2:1 wt. ratio), a AgI layer to prevent mixing of the cathode with the AgI-RbI mix layer, a AgI-RbI mix layer, an anode layer (Ag-RbAg4I5, 8:2 wt. ratio) an anode collector, and an anode lead. The battery was activated by heating to 200 degrees C for 5 min. and cooling to room temp. The discharge characteristics of this battery immediately after prepn. and after 3-hr. storage were identical.
The electrode comprises a 1:2 to 2:1 mixt. of Ag and activated C as the O-ionizing catalyst. It has improved polarizing props and is also more economical. In an example a powd. (-325 mesh) mixt. of Ag2O and activated C was blended with a 60% aq. suspension of PTFE rolled to give a thin film, and heated at 300-400 degrees C for 10 min. a Ni current collector was sandwiched between 2 sheets of the above film, a PTFE film with 1-5 mu pores was placed over 1 surface, and the laminated material was heated at 250-350 degrees V and 400-800 kg/cm2 for 5-10 sec. to give an electrode. When the current flow was measured with the potential at -0.2 V (vs. a HgO ref. electrode) the c.d. was at max. at Ag/carbon black ratio 1:2-2:1 (max at 1:1 ratio, is approx. mA/cm2). The measurements were made by placing the porous-film-coated side in contact with air and the other side with 7N KOH while using a Ni counter electrode and a HgO ref. electrode.
An alk. battery has a paperlike or feltlike separator from synthetic fibres, impregnated with a nonionic or anionic surfactant, and of improved electrolyte permeability. In an example, a polyamide fibre-sheet was passed though a 0.1% aq. soln. of a nonionic surfactant such as an alkyl ester and dried. Several layers of this material were used as the separator in a battery comprising a Ni-plated iron can, a MnO2 depolarizer, a brass anode, a Zn amalgam-Na polyacrylate anode mix, a KOH electrolyte, and a Ni-plated cover. The resp. electrolyte absorption rates of this separator and a conventional one were 30 and 121 sec. The resp. lifetimes a batteries with new conventional sepatorors in a continuous discharge though a 10-OMEGA load were 1100 and 750 min.
The Zn anode for an alk. battery is obtd. by adding to powdered Zn, powdered ZnO or Zn(OH)2, (hydr)oxide(s) of metals which are less noble than Zn and are stable in alk, soln., and the powder of a gelling agent which is stable in an alk., soln. Opt. a B cpd. and/or a crystalline cellulose may also be added. Zn anodes have desirable discharge characteristics under heavy load as well as at low temps. and possess good storage and charge-discharge characteristics. For example, a 5% ZnO soln. in 35% KOH 70 pts. was mixed with a mixt. 100 pts. contg. 10% Zn amalgam (-100 mesh) 97, ZnO powder 2, Mg0 3, and carboxyvinyl polymer powder 1.5 pts. to give a gelled anode mixt. A battery was then assembled using a cathode obtained by press moulding a mixt. contg. HgO 95, graphite 4, and polystyrene 1 pt., and an unwoven nylon separator. On continuous discharge through a resistance of 500 OMEGA at 25 degrees C and 0 degree C, the cell voltage dropped to 0.9 V after 3620 and 2135 min., resp. In contrast, a conventional battery showed a drop in a voltage to 0.9 V in 3290 and 1613 min., resp.
Air-breathing O2 electrode for low temp. fuel cells with acid electrolytes consists of two layers, one of a hydrophobic organic polymer (I) and the other, in contact with the electrolyte, of a hydrophilic layer of a catalyst (II), an inert electrical conductor and an organic binder (III), (II) consisting of polymeric phthalocyanine (IIa) or poly-p-phenyl (IIB). Pref. (I) is PTFE or polyethylene and (III) PTFE, polyacrylonitrile or polystyrene. (IIa) and (IIb) are cheaper than the Pt metal catalyst normally used in these cells.
A battery vent cap includes a pair of members between which is sandwiched a plastics membrane impermeable to battery acid but permeable to generated gases. The membrane is of microporous sintered PTFE sheet, with pores of 2-10 mu, pref. 5-10 mu. The members carry oppositely located pairs of concentric ridges between which the membrane is clamped firmly and sealingly over only a small area. One member which affixes to the battery, may be of stainless steel or a plastics e.g. acrylic, ABS or polycarbonate, whilst the other member, which acts as a resilient membrane clamp, may be of stainless steel or a plastics such as polyacrylate, polyethylene, vinyl or polycarbonate. Provides excellent venting but remains leak resistant.
In a battery having a moulded plastics vover through which projects a series of connector posts each surrounded by a bushing, connector strips are welded between the posts using a tool which includes a reservoir for temporary storage of molten material displaced from the welding area. Withdrawal of the tool enables the molten material to flow back into and supplement the welded area. Pref. welding tool comprising an inner element and a sleeve, the space between which defines the reservoir, is used.    Withdrawal of the inner element relative to the sleeve enables molten material from the reservoir to flow into the weld. Automatic machinery, having a pair of side-by-side battery carrying belts sequentially operated upon by a laterally reciprocable welding head, is described. A stronger, leakproof bond is obtd.
A solid electrolye cell with a cathode active material containing compounds with water of crystallisation has a hygroscopic material disposed adjacent the cathode to absorb the water of crystallisation liberated during cell discharge. Used for beta-Al2O3 solid electrolyte cells used in electronics and aviation. The cell capacity is increased and the useful life is increased by 15-20%. The cell pref. comprises a stainless steel anode and cathode cans, a beta Al2O3 solid electrolyte, anode active Na, a 10 mm x 2 mm cathode pellet of 70% CuSO4.5H2O and 30% graphite and a hygroscopic substance of non woven layers or pads on cloth of polypropylene or rayon fibres between the cathode and the cathode cap.
CO2 cru bber for a fuel cell reactant gas stream reducing CO2 concn. to &lt;0.25 ppm. comprises a packed bed of alkali hydroxide particles is not &gt;10 mu size and inert hydrophobic particles of a similar size. The latter are uniformly distributed and keep the alkali particles separated; the concn. of hydrophohic particles is 10-60 vol % of bed. Pref. material is PTFE. Device has low sensitivity to water vapour in the reactant gas stream.
A reserve activated primary cell has an active electrochemical material in a first flexible, hermetically sealed envelope in a housing, a second flexible, hermetically sealed envelope in the hoising and containing the first envelope and the other cell elements, such that when the second envelope is pulled through a slot in the housing, the first envelope is perforated without breaking the seal of the second envelope. For civil defense or in emergency kits for automobiles, boats, camping equipment, etc.    Provides a secure hermetic seal using inexpensive, simple construction suitable for automated step-by-step production.
Metal electrode coating with a suspension of carbon black and graphite in polymer solution is simplified by the elimination of repeated coating process, by the use of suitable carrier. The improved method uses sol. of copolymer of acrylonitrile and methyl methacrylate and itaconic acid in dimethylformamide. The proportion of liquid carrier is 40-60% W wt. based on fillers weight. The freshly coated electrode is dried for 15 mins at 140-150 degrees C. This process improves adhesion of coating to metal electrode.
The batteries with porous separators between anodes and cathodes are prepd. by adding to the electrolyte or anode a metal, e.g. Pb or Sb, whose redox potential is higher than that of the anode and whose oxide is water sol. The metal addn. inhibits the gas generation in the sealed Ni- Cd type storage batteries during overdischarge, since the metals form bridge between the cathode and anode during the overdischarge. The bridge can be destroyed during the recharging process.
Metal screens or perforated metal plates are coated with mixts. contg. metal powders and foamed binders, and sintered to give supports for alk. battery electrodes. These supports have high porosity and improved battery discharge duration. In an example, carbonyl Ni powder was mixed (1:1) with a foamed 2% Me-cellulose aq. soln., the mixt. was coated on a metal screen, and sintered 20 min at 900 degrees in N to give an electrode substrate having 75-85% porosity. The substrate was impregnated with Ni active mass to give Ni cathode which was used together with similarly prepd. Cd anode in a Ni-Cd alkali battery of 1200-mA-hr capacity whose discharge duration was is approx. 20% larger than that of a conventional battery.
Starch paste cont. 10-40 hydroxypropylmethyl cellulose (I) and 100 parts starch is coated on a paper to give a separator, which is placed in Zn can in such a way that the starch side of the paper contacts the inner wall of the Zn can, and the cathode mix is added into the separator cup to give a dry battery. The use of this separator improves the discharge characteristics and storage stability of the batteries.
A nonreactive film which inhibits diffusion of active materials from the cathode is inserted between the cathode and the solid electrolyte, and the film is removed prior to the use of the battery. In an example, a plastic (such as polypropylene film was inserted between the cathode and solid electrolyte of a battery comprising a Ag -RbAg4I5 (an 8:2 part mixt.) anode, RbAg4i5 solid electrolyte, and I -graphite -polyethylene (a 6:3:1 part mixt.) cathode; the plastic film attached to the casing material could be removed mech. immediately before the use of the battery. No change in discharge characteristics of the battery after 3-year storage was obsd.
The Ca(OH)2 -ZnO composite electrodes are prepd. by adding 10-50 parts of Zn powder of particle size 50 mu to the main-constituent mixt. contg. 100 parts ZnO, forming the mixt. into the desired shape, and subsequently electrochem, treating th eformed material. The Zn addn. increases the elec. cond. of the mixt. and results in a uniform electrochem. treatment of the mixt. Hence, the electrodes obtd. by the method have smaller lot-to-lot fluctuation in electrochem, properties. In an example, poly(vinyl alc.) binder was added to a mixt. contg. ZnO 50, 325-mesh Zn powder 15, and Ca(OH)2 35%; the mixt. was coated on the support material and electrochem. treated at 10 mA/cm2 with 2 times the electricity required to charge the ZnO electrode to give a composite electrode with excellent electrochem. properties and useful in air-Zn, O-Zn, Ni-Zn, and Ag-Zn type secondary batteries.
Acetylcellulose is used in separators of alk. batteries. The separator materials prepd. by using acetylcellulose exhibit good workability, ion permeability, and alk. soln. resistance; and batteries prepd. with the separators have improved storage stability. In an example, a nonwoven Nylon cloth was immersed in a 10% acetylcellulose (d.p. 150, oxidn. degrees 60%) soln. in acetone, dried and made into a cup-shaped separator which was used in a D-size alk.-Mn battery whose operational lifetimes at 4-OMEGA load were 27.5 and 27.4 hr after 1 and 6 months storage, resp., vs. and 27.5 and 25.0 hr, resp., for a control battery with a Vinylon separator.
Mixts. of (A) fluorinated carbon of formula (CFx)n, (in which x is a number up to 2, and n is an unlimited high number), with (B) a binder, are made by simultaneous applicn. of pressure and shearing forces to the blended components, at between the brittle and melt temps. of the binder, until virtually all of (A) is incorporated in a matrix of (B). Mixts. are used as electrodes for batteries, lubricants, etc. Loss of the very light material (A) as dust, causing inhomogeneous and variable products is avoided. The mixts. can be cold pressed and cold extruded to rigid stable products without having to be sintered.
A non-ionic surfactant (I) is used in a concn. of 0.01 wt.% in a cell operating with an organic electrolyte (II). (I) can be present in (II), pref. in a concn. of 0.01-10, esp. 0.01-2 wt.%, or present in the cathode initially and dissolved from this by (II). (I) can be an alkyl-aryl-polyether, -poly-ethylene glycol ether or -polyether alcohol. The cell has an anode of a metal less noble than Zn, esp. Na or Li, and a cathode of C-contg. material, esp. a material of the formula (CFx)n, (in which x 2 and n is an indefinite large number. Addn. of (I) improves the operation of the cell (discharge and energy density per weight or vol. unit) without familiar problems associated with the use of a low-boiling organic solvent.
Barrier layer photocell e.g. for utilising the suns energy in space travel, is characterised by the material between the electrodes consisting of (I) a solid or liquid org. material. The cell is cheaper than silicon cells and has good efficiently. (I) is pref. a diene polymer, pyrolysed cellophane, pyrolysed polyacrylonitrile, pyrolysed PVC, polyvinylene, acridine, anthracene, chrysene, coronene, dibenzodiophene, diphenyl, isovilanthrone, naphthacene, naphthalene, ovalene, pentacene, phenanthrene, p-terphenyl, pyranthone, pyrene, stilbene, violanthrone, or a photoconducting org. dye.
A battery cap comprises a skirt portion with a transverse partition was defining an outwardly opening cavity and an interior cap portion, the wall having a central aperture, and a filter being secured in the cavity, the filter having a central inwardly concave dome-shaped recess communicationg with the aperture and defining with the adjacent outer surface of the filter a reduced thickness central portion of the filter thinner than the surrounding filter portions. The cap has improved flame retardation.
Electrolyte immobilising separators for Leclanche cells of the type using a comparatively dry pressure-molded bobin of depolarizer mix and a Zn anode which also serves as a cell container are made by introducing into the cell container a separator forming material comprising a soln. of vinyl material and electrolyte under pre-determined and controlled viscosity levels, introducing the bobbin into the cell container in such a way as to form a layer of separator material between the cell container and the bobbin while simultaneously gelling the soln. by polymn. and crosslinking in situ and controlling the viscosity of the soln. during the gelation. The separator forming material is prepd. by forming an initial soln. of polyacrylamide and electrolyte and pref. a complexing agent, and mixing this with vinyl monomer and appropriate gelling agents.
In a planar battery having a number of electrically conducting layers cooperating to form a multicell battery, (a) a continuous, frame-type, electrically insulating sheet sealant has a surface adjacent its inner opening thermally bonded to the peripheral surface of each conducting layer and extends outwardly from the conductor to form a continuous border sealing portion, and (b) discrete separator sheets are disposed between superposed conductors with their edges extending beyond the inner opening of the frames sealant but not beyond its outer edge. Specif., the frames are of thermoplastic material and are bonded to sheet-type conductive thermoplastic electrode supports which combine with electrode active materials and electrolyte to form electro-chemical cells. The frames are located in registry and are mutually thermally intersealed along the border sealing portions. The shelf life is compatible with that of the associated film.
The assembly comprises a polypropylene container covered by a cap of polypropylene, the container and the cap or the cap and a lead electrode rod of a battery inserted in the container being bonded firmly with a bonding agent consisting of 50-90 wt. % of tar epoxy resin and 10-50 wt. % of polypropylene chloride.
Dry cell comprises a cathode carbon rod, a cathode activator a zinc can anode an electrolyte contained in the can and a separator separating the cathode and the anode. The separator comprises a fibre sheet of high wet tensile strength contg. &gt;60 wt. % synthetic fibre and porosity &gt;70%, and a hydropile polymer layer stuck to the fibre sheet. Used in a Leclanche cell.
A dry cell comprises a cathode carbon rod; a cathode activator, zinc can anode; an electrolyte, and an electrode separator paste supported on kraft paper and a PVA film. The kraft paper/PVA is formed into a cylinder with using thermosetting resin.
A dry cell comprises a cathode carbon rod; a cathode agent consisting of electrolytic MnO2 acetylene black, MH4Cl, ZnCl2, and water; a zinc can anode, an electrode separator and an electrolyte. The separator comprises a paste layer supported on kraft paper with a copolymer of vinyl acetate and crotonic acid.
A liq. level indicator combined with a hydrometer, for use in storage batteries consists of long rod passing through the centre of a cap of elastic material fitted at the upper end of the rod. The upper cross-sectional surface of the rod acts as a sighting surface for light reflected from the lower end. The rod is surrounded by an orifice connecting the inside of the battery with the atmosphere and the orifice is plugged with a stopper in the form of a porous flame-trap. The material of the cap is such that when the cap is fitted to the rod the elasticity of the cap forms a compression joint with the flame-trap locating it firmly in position. The flame trap is of a low conductivity material, pref. polyvinylfluoride. If flammable gases seeping through the flame trap should ignite, there is sufficient time for action to be taken before the heat is conducted to the cap and rod.
Cathode for electric cells contains CrO3 and an electric conductor. The CrO3 is pref. incorporated in the laminar structure of the conductor, esp. graphite. The cathode pref. also contains a binder, esp. PTFE. Typically, it consists of a mixt. of CrO3, acetylene black and PTFE in 7:2:1 wt. ratio on an expanded Ni support. It is used in cells with an anode of a metal less noble than Zn, esp. Li, a separator and a compatible organic electrolyte, pref. LiClO4 soln. in propylene carbonate. The cathode has a high enery density and can be produced easily and at relatively low cost. CrO3 and the other components used are readily available.
A process for mfg. electrode grids for lead accumulators using non-metallic base matls. which can be electroplated, pref. plastics. After moulding to the required shape, during which lead inserts required as terminals etc. are placed in the die, either the individual grids or the complete stacks are electrolytically treated so that the plastic mouldings are coated with a layer of copper up to 50 mu thick, followed by an outer layer of pore-free lead, 5-50 mu thick, i.e. using galvanoplastics.
A dry cell having a separator between anode and cathode is produced by adding to an aq. soln. of electrolyte salts and polyacrylamide, a Cr-contg. cpd., the Cr having a valency other than +3, and a cpd. reactive with the Cr-cpd. to produce Cr3+ ions, mixing to form a separator mixture, and placing the mixture next to the anode. Using the Cr- contg. cpd. as cross-linking agent for the polyacrylamide ensures that the degree and time of cross-linking can be accurately determined and controlled, and paper liner degradation kept to a minimum. The separator may be used in all zinc chloride electrolytes and displays good high-temp stability.
A dust-free uniformly leaded plate for lead-acid storage batteries comprises a leady paste on a supporting grid covered with a thin layer of water-soluble film-forming polymeric cpd. The film is applied to the leady layer after applying it to the grid, then dried, and is removed during plate formation. The temporary coating minimises prodn. of leady dust in plate mfr., but permits transmission of O2 and water vapour during plate curing. The coating is from polymerised-polyvinyl alcohol, -polyethylene oxide, -water soluble alkyl celluloses or a water-soluble starch, and may include a viscosity-modifying agent, a plasticising agent, an extending agent and/or an antioxidant agent. The coating may be applied as an aq. soln., esp. by immersing the plate into the aq. soln., as a fine powder to an aq.-wet pasted plate or as a self-supporting film.
An alk. battery has an anode prepd. by press moulding a mixt. of Zn amalgam powder, Zn amalgam fibre, and a material which gels on absorbing the electrolyte. These batteries have Zn anodes with a large surface area which hold large vols. of the electrolyte and possess good mech. as well as elec. props.
In iron electrode mfr. particles of an iron powder, an iron oxide or an iron hydroxide are mixed with a castable org. resin, cast into a electrode mould and the resulting casting heated to is not &gt;950 degrees C in an inert atmos. to carbonise the organic resin.    The pref. ratio of iron particles to resin by wt. is 1:1 to 8 and the iron may be mixed with soot the pref. ratio rion-soot: resin being 8:1:-2. The electrode is pref. cast at a temp. of 100 degrees C using a pressure of 70.3 kp/cm2. Used for batteries, metal-air batteries and e.g. nickel-iron batteries (Edison cells). The operation performance of these electrodes is at least equal to that of the conventional electrodes which consist of a sintered Ni fibre mat or Ni-plated steel wool fibre filled with iron oxide, while being significantly lighter in wt. and also less expensive to produce.
Electrode for use in metal-air batteries comprises a hydrophilic layer contg. a mixt. consisting of a 25-40 wt.% carbon for absorbing or reducing oxygen, 50-70 wt.% MnO2, 1-9 wt.% PTFE and/or a fluorinated ethylene propylene copolymer and a metal fibre current collecter, integrally moulded into the mixt. to form the layer, and a hydrophobic layer of porous non-sintered PTFE completely fibrillated and rolled onto the hydrophilic layer. The mixt. may contain a Hg-Ag catalyst. The electrode is used in a secondary, rechargeable battery with KOH as electrolyte and a Ni or nickel steel counter electrode. The electrode avoids the prior art problems of high polarisation and loss of performance with increasing temp.
The proposed electrode comprises metal substrate acting as current lead, porous hydrophobic layer, non-conducting layer consisting of both hydrophobic and hydrophobic materials and the usual active layer. The substrate may be a mesh or may be made of porous material and the active layer is constitute by a mixture of Pt, Ag or active carbon and polyfluroethylene resin. In general the hydrophilic material is oxides of Si, Al, Zr, Ti, etc. and the hydrophobic material is polyfluoroethyelen resin, polyethylene, ptfe, paraffin etc.
The cathode for an alk, battery is obtd. by pressure contacting an ion-permeable, insulating, porous plate on the surface of a cathode mist. obtd. by moulding a cathode-active material, a conducting material, and a binder. Batteries obtd. with this cathode are leak-proof and possess improved heavy-discharge (large load) and storage properties. In an example, a cathode mixt. was obtd. by compacting Ag2O 85 pts., graphite flakes 10 pts. and polystyrene powder 5 pts. A porous, ion-permeable, insulating plate obtd. by pressure moulding a mixt. of TiO2 90 pts. and portland cement 10 pts. was pressed on the moulded cathode mixt. to give a cathode. This cathode was placed in a metal can, a cellophane separator was placed in contact with the porous plate, an anode material consisting of a Zn amalgam powder was placed on the cellophane sheet, and a metal cover was used to enclose the battery after adding 8N KOH as the electrolyte. Few batteries prepd. in this manner leaked in storage for 12 months at 45 degrees. The battery showed a short-circuit current of 0.60 A and an open-circuit voltage of 1.57 V. A conventional battery fabricated without the use of the ion-permeable plate gave for the corresp. measurements 0.45 A and 1.57 V, resp.
Dry cells are obtd. by incorporating NH4Cl coated with a material, which is sol. at pH 5.5, into the paste layer and/or the cathode mixt. In an example, NH4Cl (200 mesh) was coated with cellulose acetate phthalate (I) by suspending NH4Cl granules in a soln. of (I) 1 kg in Me2CO 20 than centrifuging to remove the excess liq., The coated NH4Cl 15 pts. were mixed with a suspension of etherified starch 40, Me cellulose 2, and water 43, then coated (40 g/m2) on kraft paper to give a separator. The separator was placed in the Zn can so as to have the paste-coated layer come into contact with the inner walls of the Zn can. The bottom paper layer was placed in posn. and the can was packed with MnO2, acetylene black, and an electrolyte consisting of ZnCl2 23, NH4Cl 3 and water 74% (pH adjusted to 5.0 with ZnO). The electrolyte of the above compsn. was then poured in, and after the liq. was absorbed, a C rod was inserted in the middle of the can. The can was then sealed in the conventional manner to give a dry cell. A cell prepd. in this manner showed short-circuit currents of 8.5 and 8.0 A for measurements made immediately following fabrication and after 12 months storage, resp., the discharge capacity of 4 30 and 400 min, again for measurements made immediately following and 12 months following fabrication, resp. A conventionally prepd. cell, in contrast, showed values of 8.5, 7.2 A and 430, and 350 min for the corresp. measurements.
Sepg. material for a lead accumulator consists of (a) glass fibres, (b) thermoplastic synthetic fibres, and (c) finely-divided porous silica, and has porosity &gt;60%, pore width &lt;3 mu, and thickness &lt;0.2mm. fibres (a) are pref. 0.2-0.4 mu dia, 0.1-4.0mm long, with average length 0.6mm. Fibres (b) are pref. 5-30 u dia, and 1-2mm long made of polyamide, polyester, polyvinyl resin or polyolefin, esp. polythene or polypropylene. The silica (c) is pref. diatomite of &lt;10 mu. The pref. mixt. has ratio (a):(b) of 1:1.5 to 1:2, and (a + b): (c) of 1:0.5 to 1:1, the mixt. being formed into sheet at 5-10 kg/cm2 and 110-180 degrees C. The walls have a thickness &lt;0.2mm and pore width 3 mu so a compact battery can be made low energy loss on charge and discharge, and which provides easy starting for motor car engines.
Graphite powder is dispersed in a polyolefin soln. and cooled to ppte. the polyolefin to give composite powder which is pressed into a moulding. Graphite electrodes are moulded. In an example, graphite 360, low-density polyethylene (I) 40, and xylene 2000 g. were heated at 95 degrees, cooled to 35 degrees with stirring, centrifuged, and washed with MeOH. The powder was pressed at room temp. at 2 tons/cm2 to give an electrode with resistivity 0.1 cm. A mechanical blended compsn. of 120 g. (I) and 280 g. graphite could not be pressed into an electrode with useful mechanical strength.
In a dry cell a polyvinyl alcohol film having a degree of saponification of 98 to 99.9 mol. % is positioned in the separator as a checking film. The checking film serves to prevent paste from moving to the cathodic mixture side. The film has low solubility in water and electrolyte, and remains in swollen state during storage and discharge, and has high ion diffusion velocity.
Chem. resistant diaphragms with sp. elec. cond &gt;1 x 10-3 mho/cm and water permeability &lt;30 1./m2hr (at a pressure differential of 0.1 kg/cm2) can be obtained from polymers contg. the monomeric unit CF2CR1R2 (R1,R2 = H, halo or halomethyl) and finely divided (&lt;1000 nm) SiO2 gel. These diaphragms are useful in brine electrolysis cells.
A leakproof primary cell with a cylindrical positive electrode, a cup-shaped negative electrode, an MnO2, depolariser and an electrolyte consisting of Zn Cl2 and NH4 Cl is encased in a shell consisting of three layers. The inner and outer layers consist of PVC or PVC coated paper, and the centre layer consists of wrapping paper. This prevents any capillary effect on the outer layer, also any additional wick action so that perfect sealing is achieved.
Laminate comprises (i) a layer of thermoplastic polyester (I) and (ii) a layer of crosslinkable polyethylene (II). The m.pt. of (II) being &lt; that of (I) and the layers are directly crosslinked at the interface, (I) which pref. contains a fibrous (esp. glass) filler, is a highly polymerised ester of terephthalic acid with a glycol HO(CH2)nOH (n = 2-10). (II) pref. contains a halogenated flame retardant. In prodn. of hollow, rotationally-moulded structures, esp. cases for large storage batteries. The outer (I) layer has high impact strength and (II) is resistant to chemical degradation. (I) pref. has m.pt. 400-500 degrees F and is esp. 'Celanex' (RTM) of particle size 30-40 mesh. (II) contains a crosslinking agent such as dicumyl peroxide, and pref. a flame retardant e.g. 'Flamolin' (RTM). It has m.pt. 250-300 degrees F and particle size of 50 mesh.
A lead acid storage battery comprises an envelope-type separator formed from a folded microporous synthetic resin sheet having 10,000- several 100,000,000 micropores/cm2 with dias. of 100A-several mu, having parts of at least one of its sides sealed together and provided with slits in its folded section. A battery plate having at least one leg is provided, and the separator is arranged so that enough of the folded section is left slit-free to provide a protective cover for the leg and so that active material generated during operation can drop from the battery plate. Generated active material does not accumulate to short circuit the plates or tear the envelope. The separator covered plate can be mass produced.
In order to mechanize the process and improve the quality of dry-changed zinc electrode for pasted plate silver-zinc storage cell or batter. The method claimed in Parent Certificate No. 120551 is modified as follows: zinc dust and zinc oxide mixt. moistened with polyvinyl alcohol is granulated and pasted on to electrode which is then pressed at 100-300 kg/cm2. Then treated with polyvinyl alcohol contg. inhibitor and dried at 50-70 degrees C.
An exhaust member for batteries comprises a water repellent film made by binding graphite fluoride particles with silicone resin and formed on the surfaces of a porous member, the amt. of the graphite fluoride particles being less than 10% of the silicone resin.
Method comprises heating and mixing soft linear high polymer and carbon powder to make a conductive film with a desired thickness by using rollers, cutting a part of the film dissolving and dispersing the cut film in a solvent to make a coating matl. coating the matl. on a zinc plate to make a thin film on the heated zinc plate by rollers.
Dry cell comprises a polyethylene tube covering an outer surface of a zinc can provided with a generating element, and a sealing cover for blocking the zinc can. The cover is composed of a matl. having a heat adhesion with the tube, to form a liq-tight. seal between tube and cover.
A rechargeable zinc electrode for accumulators using alkaline electrolytes, consists of layers of zinc and/or zinc cpds., mixed with addns. which, during the discharge cycle form cpds. with the Zn which are difficult to dissolve; each layer contains a mesh carrier with a thickness equal to the thickness of the layer. The carrier is pref. 0.1-5 (0.8)mm thick with a mesh length 1-50 (10) mm. and mesh width 1-50 (10) mm. The carrier may be fibres or threads of alkali-resistant plastic, esp. a hydrocarbon polymer, polyamide or PVC, the carriers being housed in a plastic frame. Alternatively, carriers made of expanded metal, esp. Cu or Cu coated with Zn or Cd, may be used. Provides a mechanically stable electrode which is simple and inexpensive to mfr. In general, the carrier is made of non-conducting material but in one embodiment the innermost layer uses a metal carrier which also acts as a current lead, esp. expanded metal. The threads of the plastic carrier may lie in the same or different planes to form the mesh, and suitable plastics include polypropylene, polythene, and esp. PTFE.
A non-acid battery paste is produced by forming a slurry of litharge and a water-sol anionic polymer in water and then incorporating a water-sol lead salt into the slurry to from a battery paste. The paste may be applied to battery grids which are cured to provide plates for assembly to form a lead-acid storage battery. The thick paste is stable over prolonged storage periods and has the required consistency for application to battery grids to provide a lead-acid storage battery having high storage capacity.
A non-acid battery paste is prepd by forming a slurry of litharge and a water-soluble anionic polymer in water and adding at least one of HNO3, H2SO4, SO2, SO3 and N2O4 to form a paste. A surfactant or nonionic polymer may be added to improve gas entrainment props. etc. The paste is used in lead-acid storage battery electrodes. Storage capacity is improved and the paste has good mechanical props cor curing, drying, formation, discharge and re-charge.
Rough surfaced or porous electrode attached to a matrix for acid electrolyte electrochemical cells, esp. fuel cells has a matrix separating the two electrodes which by expansion, undergoes an increase in volume and onto which the electrolyte is adsorbed chemically or physically, the surface of the matrix adapting itself to the shape of the electrode. Prevents loss of electrolyte acid and water over long periods and allows the tolerances on some of the parts of the battery to be somewhat relaxed. Diffusion of ions between the electrodes is improved, and the electrodes can be much thinner than in prior art so that diffusion of ions is easier.
A planar battery comprises (a) superposed, planar coextensive anode(Zn) and cathode (C and MnO2), (b) a planar separator between them having an aq.-electrolyte-permeable centrla portion contg. aq. electrolyte (ZnCl2 and/or NH4Cl) contacting the electrodes and having marginal portions, (c) an electrically nonconducting, water-vapour impervisou, heat-activated thermosetting adhesive coextensive with a marginal portions of the separator, securing them to adjacent electrode portions, comprising the reaction prod. of a polymer contg. active H ats. and a thermally dissociated adduct of a cpd. contg. at least two -N=C-X gps., where X is O or S, and the adduct is based on a cpd. from phenols, alkyl and aryl thiols and 1,3 dicarbonyl cpds. The adhesive gels in 2-10s at 300-400 degrees F, with further curing during cooling, compared with up to 30 min. for other adhesives.
Dry cell separator paper is made from partially acetalised polyvinyl alcohol and is capable of absorbing gelatinised electrolyte powder.
Battery comprises Mg, Al or its alloy as anode reducing agent, PbO2 as cathode oxidising agent and neutral salts as electrolyte.    The cathode is a lattice made of synthetic resin coated with Pb, Cu or Ni and further coated with Pt, Au, Nb Ta, Cr, Mo, W, Ti, Zr, Hf or Sb. The coating being carried out electrically.
An O2-electrode is made by (a) forming a homogeneous mixt. of Ag and intrinsic semiconducting CuO, (b) blending with hydrophobic polymeric material to form a homogeneous paste, (c) drying, (d) mixing the paste with softener to form a pliable dough, (e) rolling to thin foil form, (c) heating to cure th polymer and form a foil and (g) bonding into a proous support to form the electrode. The electrodes provides performance characteristics similar to those obtained with more expensive catalysts. The depolariser material is also useful as an oxidn. catalyst for alkenes, alkynes and alkanols.
A hydrophilic electrode contg. electrochemically convertible active material is made by (a) blending powdered actible material with 0.1-3 wt. % dry powdered PTFE in an excess of nonaq. lubricant to form a homogeneous mixts., (b) removing pt. of the lubricant to form a filtered mixt., (c) subjecting the mixt. to shear force to reduce its thickness while maintaining below the PTFE sintering temp., forming a sheet of fibrillated PTFE contg. lubricant and active material and (d) removing the remainder of the lubricant at below PTFE sintering temp to form the electrode structure. A filler material of higher electrical conductivity than the active material may be incorporated in the structure by including it in the original blend.
Dry cell includes a coating agent for forming a block of unit cells, which is composed of copolymer emulsion of methyl methacrylate and butadiene with cross-linking melamine resin.
The process is for mfg. spherical semiconductor particles from semiconductor particles held at a suitable reaction temp. in a fluidised bed and exposed to a vapour contg. a semiconductor, a reducing agent and a dopant (I) of one conducting type so a deposit is obtd. in a specific time; dopant (I) is then replaced by dopant nII) with the opposite type of conductivity so a second layer of type (II) is deposited. The initial particles are pref. monocrystalline Si, 150-350 mu thick, layer (I) being n-type Si doped with P in the presence of H2, and layer (II) is pref. epitaxial, p-type Si, doped with boron and 1-10 mu thick, the resultant spherical particles being 650-850 mu dia. Used in the mfr. of solar cells. The spherical particles can be directly used in devices without the need to make slices or chips which are expensive and involve a large amt. of scrap material.
This is an addn. to 2048796 which described the mfr. of a sheath for the active mass in a lead accumulator, made from an oxygen- and acid- resistant plastic granulate with an extremely small grain size, where the plastic granulate was hot- or cold-sintered in dies to an open, micro-porous ske-framework of the desired shape. In the present invention, for hot sintering a die is used made of a material with good thermal conductivity which is heated to the sintering temp. and brought into contact with the plastic; for cold sintering a die is sprayed with a liq. which dissolves the plastic, after which the plastic is spread on the die to the required thickness and dried. At least the inner wall of the sheat is pref. coated with an ion conductor viz. lignin sulphonate or colloidal graphite. A mechanically strong, porous sheat is thus inexpensively mfrd.
Method comprises drying a film of polyvinyl alcohol with air to oxidise it, and subjecting the oxidised film of polyvinyl alcohol to the alkali treatment so as to render it insoluble in water. The film absorbs a large amt. of electrolyte and hence has excellent electric conductivity. The internal resistance of the alkaline battery is not increased.
A dry cell has a separator consisting of a separator paper, a laminated film composed of polyvinyl alcohol or polyvinyl alcohol and a matl. having water absorbing property, water retaining property, swelling property and/or binding property attached to one surface of the separator paper, and a paste layer spread on the laminated film, between the cathod mixt. and the anode zinc can.
A dry cell comprises a three-layered separator consisting of a separator paper with water-absorbing and water-retaining props.; a PVA film opt. having either water-absorbing or retaining prop; and a PVA film having at least water-absorbing, water-retaining and binding props. The assembly is arranged between a cathod mixt. and an anode zinc can.
A separator for a lead cell comprises a paper consisting mainly of pulp and also contg. glass fibre. The paper is impregnated with an acid resistant synthetic resin such as phenol resin, and coated with an acid resistant synthetic resin contg. SiO2 powder with particle of size &lt;1 micron. The separator is suitable for use in a car battery and has a long service life.
A carbon zinc composite electrode for a layer built cell is made by mixing carbon powder with a linear high mol. wt. polymer cpd. with heating, rolling the mixt. to a film of predetermined thickness, dissolving the surface of one side of the film in a solvent, and pressing that side of the film to a zinc plate.
A layer-built battery comprises a pluraility of cell units, a terminal plate on the top of the cell units, a bottom plate, an outer casing, and a thermoplastic resin layer disposed at the inner surface of the outer casing and the outer surfaces of the terminal plate and the bottom plate. The cell units are sealed by heating the thermoplastic resin layer.
Method of mfr. comprises (1) forming a synthetic resin in the desired shape, (2) roughening the surface of the formed synthetic resin, (3) activating the synthetic resin in an acid soln., (4) plating the formed synthetic resin with a metal, e.g. Cu, to form a plating layer on the surface and (5) coating a conductive paint consisting of epoxy resin, polyamide and acetylene black on the plating layer. Roughening the surface produces better adhesion of the electroplated metal.
The cell is of similar general construction as that in J7 5018173. The separator comprises a coating of crotonic acid-modified vinyl acetate on the Zn anode container, and contg. electrolyte. Diffusion with electrolyte of the cathode paste is eliminated.
The cell is of similar general construction as that in J7 5018173. The separator used comprises a laminate of electrolyte-impregnated swollen, hygroscopic kraft paper and polyvinylalcohol film.
Dry cell comprises a cathode carbon rod covered with a cathode paste consisting essentially of MnO2, acetylene black, NH4Cl, ZnCl2 and water, a polyvinyl alcohol separator contg. electrolyte, e.g. NH4Cl, surrounding the cathode paste. a second paste layer contg. electrolyte covering the separator and a zinc anode container contg. the anode, the separator and the second paste layer.
Battery has a water proof porous sheet packing the cathode, the anode and the separator, wherein the separator prevents leak of electrolyte in the porous sheet from the sheet to outside. The porous sheet consists of synthetic resin, e.g. polyvinyl chloride, polystyrene, copolymer of vinyl chloride and vinylydene, polytetrafluoroethylene etc. System is used n alkaline-, lead storage-, manganese-and air-batteries.
Gas-diffusion electrodes for batteries are made by laminating a catalyst layer contg. a mixt. of a powdered catalyst and poly(tetrafluoroethyelene) (I) a metal grid (such as expanded metal) and a porous (I) sheet, the pressing is carried out by placing the porous sheet on an elastic rubber surface to give an uneven surface with impressions of the metal grid. These electrodes are useful in fuel cells and metal-air cells. In an example a porous tape (0.2 mm) was obtained by rolling poly(tetrafluoroethylene) powder with a lubricant. A catalyst layer was prepd. by spraying an aq. suspension of (I) and Ag coated activated C on an Al foil and drying. The catalyst layer and the porous sheet were pressed together and the Al foil was peeled off. A Ni expanded metal grid was placed on the catalyst surface, the combination with a rubber support was pressed at 150 kg/cm2 and the laminated sheet was heat treated at 250 degrees C for 3 min.
In an example, a Ni-Cd battery consisting of a dish-shaped container of Ni-plated Fe (pos. terminal) and a Ni-plated Fe cover (neg. terminal) with a polypropylene packing material, and contg. a Ni(OH)2-contg. Ni cathode and a Cd(OH)2-contg. anode sepd. by an alk-material-contg. separator was coated (5-100 mu) with poly(p-xylene) at 500-700 degrees and 10-2-10-3 torr. Batteries prepd. ones and show no leakage on storage at 30-5 degrees and 89-90% relative humidity for 12 months; the discharge capacity after 12-month storage dropped to 98% (av.). Their capacity decreased to 94% after 300 cycles.
Separators for alk batteries are obtained by heating poly-(vinyl alcohol) films to crosslink part of the OH groups present in the polymer. This eliminates the washing by water required in the conventional acetal process, and the handling of H2SO4. In an example, a film obtd. by heat treating a polynvinyl alc.) film at 100 degree C for 10 min. gave a separator for a Cd-Ag alk. battery which withstood 150-200 chargin-discharging cycles with no drop in capacity. It showed similar performance characteristics as the film obtd. by the conventional acetal process.
A fuel cell has a pair of oppositely situated electrodes with an electrolyte matrix between them, at least one electrode having a continuous hydrophobic surface and with an electrolyte store behind one of the electrodes. The electrolyte store is a storage matrix contg. an aq. electrolyte similar to the electrolyte matrix with which it is connected via selected non-hydrophobic points, distributed uniformly over the whole hydrophobic surface of the electrode and having an insignificant expansion relative to the hydrophobic surface. This construction enables a matrix fuel cell to be produced with an electrolyte container connected to the electrolyte matrix, without bulky or costly components, e.g. special separator plates.
Three-layer electrode, partic. for a fuel cell, consisting of a continuous carbon fibre substrate, supporting and partly impregnated by, a graphite-hydrophobic lower layer, on which in turn a catalytic-hydrophobic plastic layer is present, the preferred hydrophobic plastic being p.t.f.e. the use of the hydrophobic lower layer gives a lightweight electrode (air cathode) enabling approx. 10% higher emf to be produced from a H2-O2 fuel cell operating at 135 degrees C with 96% aqueous H3PO4 electrolyte.
Electrode comprises conductive C and &gt;50 wt. % PbCl2 (on total C+PbCl2) with a urea-formaldehyde polymer binder on a metal grid.    Pref. wt ratio of PbCl2 to C (graphite) is 70-95 and 30-5; urea-formaldehyde content is 0.5-12 wt. % of composite and grid is a Cu, Ag or Ni (alloy) screen. Electrode is esp. suitable for use in a primary cell adapted to be activated by seawater. It has a long shelf life, high mechanical strength and is lower cost than AgCl electrodes.
In a fuel cell involving catalytic anodes and cathodes sepd. by membranes into cells swept by aqs. electrolyte streams mixed with a gaseous fuel and an oxidising gas resp. the cells are extended vertically to provide overhead chambers for condensing and refluxing vapours (water) entrained in the gaseous stream(s) (fuel, air). The cells also incorporate reagents for decomposing any carbonates generated in situ into CO2. Used esp. for cells involving carbon based electrodes and swept by atmospheric air, using methanol, antural gas (methane) or hydrazine fuels. The cells may be enclosed in a plastic casing. Reduces water (or methanol) losses to allow cells to operate at higher temps. for increased power outputs. Cell life increased by suppression of carbonate build-up.
Cellulosic permeable battery separators comprise a cellulosic substrate impregnated with a phenolic resole with a number av.mol.wt. of 130-300 and a combined aldehyde:phenol ratio of 1.6-2.8:1 and an anti-migratory agent for reducing the degree of migration and improving the oxidative resistance selected from phenol, o-, m- and p-cresol, hydroquinone and catechol such that the ratio resole : anti-migratory agent = 100: 7-32, and the resole is advanced to an infusible state. The separators exhibit improved oxidation resistance in an acidic oxidising environment, and give batteries with longer life.
Dry cell comprises a Zn anode, a cathode mixture, and a film of vinyl acetate driv. between the Zn anode and the cathode mixture, the vinyl acetate driv. having a degree of saponification of &lt;40 mol. % and being modified with crotonic acid in amt. &lt;30 mol. % thereby forming Zn salt with carboxyl group of the crotonic acid.
A paper is impregnated with a soln. contg. either boric acid or borates and coated with aq. PVA soln. to give a separator for dry cells. The boric acid or borate gels the PVA very quickly and prevents the diffusion of the polymer into the paper, giving a separator of good electrolyte retainability and dry cells with improved discharge props. The separation obtd. exhibits good swelling in the electrolyte soln. and good ion permeability. In an example, paper was treated with a 4:6 H2O-alcohol mixt. contg. 0.5-4 wt.% boraz by using a rubber roller wetted with the soln., coated with aq. 10-40 wt. % PVA soln. by using another roller coater, and dried.
Batteries of improved shelf life contain electrolytes dissolved in Lewis base-type org. solvents, and an Al substrate for the cathode. The fluorinated graphite reacts with the Al substrate to form Al fluoride in the boundary region which prevents dissolving of Al, and the C produced by the reaction maintains the electrical conductivity of the electrode. A tetrafluoroethylene-hexafluoropropylene copolymer may be used in the prodn. of the cathode.
In forming an envelope from a thermoplastics sheet, the sheet is heated along a transverse line about which the sheet is subsequently folded by a plow member which is reciprocable from a position spaced from a pair of guide members to between the guide members; and the sheet is heat sealed along its longitudinal edges while folded about the plow member. The envelopes are pref. used as bettery separator blanks.
A separator for a dry cell comprises a base paper in which a layer of very fine paper at least 10u thick having a density of 0.65-0.85 g/m2 coated on one side only with a (starchy) paste material. The fine paper is pref. in contact with a layer of coarse paper having a density of 0.45-0.55 g/cm3. The cell is specif. a dry cell having a Zn anode and a depolariser, the coated side facing the anode. The fine paper prevents migration of paste material and fine particles included in the depolariser more effectively than a coarse paper, and its thinness helps maintain favourable ion permeability. The coarse paper layer provides structural strength, and assists paste adhesion.
The beta-and beta" -alumina ceramics are obtained by diffusing divalent metal ions in a melt contg. A1203 and Na2O, cooling, pulverizing, compacting the powder, and firing. The ceramics of high density and uniformity, and obtained at low sintering temps are useful as the solid electrolyte in secondary, esp. Na-S batteries. In an example, a mixt. of a-A1203 84.9, Na2CO3 12.2, Mg0 1.9% was arc melted cooled and pulverized. This powder (1.02 mu) 2 g was mixed with 5% poly(vinyl alcohol) 10%, pressed (1 ton/cm2) to a disk (diam. 20, thickness 8mm), heated (200 degrees/hr) in air at 800 degrees C, held at this temp. for 30 min, and sealed in Pt and heated at 1600 degrees C for 2hr. The product had grain size 5 m mu, d. 3.28 g/cm3, its main phase was beta-alumina.
The batteries are obtd. by placing the electrode-plate assembly in an ebonite or plastic case contg. a mixt. of a synthetic-resin powder contg. a foaming agent and powd. hydrated SiO2 gel, steam heating at &gt;100 degrees C to cause foaming and hardening of the foam within the case, and pouring the electrolyte into the foam-packed case. In an example, an electrode assembly was placed in an eonite case, a mixt. (2:5) of a phenolic foamable resin powder and hydrated SiO2 gel was added, and the case mixt. was heated with steam at &gt;100 degrees C. The case was filled with H2SO4 (d. 1.28) and the battery was charged. The battery suitable for portable and emergency equipment has a charge-discharge source lifetime of &gt;300 cycles (100 for conventional one) and showed very slight liq. loss.
In a battery for a heart pacemaker which has connections to be joined to the patient's heart as well as a pulse generator supplying stimulations pulses to these connections at predetermined intervals and supplied from a battery which together with the pulse generator is encapsulated in an insulant, the improvement whereby the battery contains an insulated duct sleeve, pref. consisting of neoprene, installed between the positive and a negative electrode of the battery and acting as insulation between these electrodes, the duct sleeve being so constructed that it provides a surface contact zone between it and an insulant partic. an epoxide resin in which a joint can be made, resulting in liquid-tight coverings over the positive and negative electrodes. By reducing or eliminating leakage currents e.g. due to body fluids, useful energy obtained from the battery is increased so that the length of life of the heart pacemaker is increased.
Fine tubular matls. consisting wholly or in part of thermoplastic fibrous matter resistant to 40% sulphuric acid and reinforced with acid-proof synthetic plastics, have the fine tubes created, by bonding together two lengths of fabric with lengthways seams placed close together and fixed by moulding inserts, under the action of heat. The fabrics used are produced from fibrous fleeces, sew-knitted with tricot stitches in fine threads, pores of an average diameter of 0.3 mm being formed. The fibres in the fleeces include meltable and/or shrinkable matls. which during the heat treatment bring down the holes at the piercing points of the needles to the size of the average pores in the product. Cheaper to produce, improved characteristics. Sufficiently flexible to accommodate the varying dimensions of the lead mass without being permanently deformed.
Foamed synthetic resin powder and SiO2 gel contg. water are mixed, and the mixt. is hardened by steam at 100 degrees C to give a highly porous, water-absorbing material with good hydrophilicity and useful as electrolyte supports for batteries, and as filter matls. In an example, 2 pts. foamed phenolic resin, and 5 pbw SiO2 gel (contg. 70% water and 100-200 mesh) were mixed; heated with 180 degrees C steam for 1 hr; and dried for 2 days at 80 degrees C to give a porous material having a porosity of 81.3%, c.f. 68.3% for a control, heated in air instead of steam.
High-d. C products (e.g., arc electrode) are manufd. by adding 2-20 wt.% polyethers (mol. wt. &gt;200) to a raw mix of powd. C and pitch and moulding the resulting mixt. In an example, 100 parts coke (&lt;150 mesh) and 2k parts petroleum pitch (softening point 170 degrees) were mixed at 200 degrees and ground to &lt;100 mesh, and then 10 wt.% polyethylene glycol (mol. wt. 400) was added. The mixt. was compression-moulded at 1 ton/cm2 to obtain a moulded C product having d. 1.54g/cm3, compared to 1.32 for that made without polyethylene glycol. When the moulded C product was heated to 1000 degrees 10 degrees/hr, the wt. lsos and shrinkage were 13.4 and 21.4% resp., and the resulting sntered C product had d. 1.7g/cm3.
A battery separator having foamed plastics ribs and abody of non-woven plastic fibrous webbing is made by compressing, by calendar rolls, a gas laid non-woven fibrous plastics web, passing the web over an upwardly convexly curved back-up plat (32), and extruding foamable thermoplastics ribs onto the web from a multi-orifice die located above the plate. The ribs may be compressed to flatten them by passage of the web through pressure rollers. The curved plate compensates for the shrinkage of the ribs and produces a plate having improved abrasion resistance, compressive strength, stiffness, and thickness uniformity.
Method comprises applying to a sheet, the main component of which is rubber or thermo-plastic synthetic resin, a soln. consisting of acid-resistant synthetic resins and/or their copolymer esters, and ion-exchange resin powders resolved (sic) in a solvent, the amount of ion-exchange resin powders being is not &lt;60% w.r.t. the whole separator. The battery has a long life.
The electrode comprises a porous member of fluorine-contained resin produced by heat-treating the resin, a porous member of fluorine-contained resin produced without heat treatment, and a composite porous member composed of fluorine-contained resin powder and being disposed between the porous members, said composite porous member being arranged to a gas side.
A paste layer for dry cell is mfd by mixing methyl cellulose with cross-linking starch to make a volatile org. liq. which is coated on a separating paper and dried.
Shaped caron products are obtained by blending C powder with a mixt. obtained from the initial condensation prod. of polymers contg. furan rings and bituminous materials, moulding, and firing. These C products are useful as electrodes for dry cells.    In an example, graphite powder (90% &lt;300 mesh) and a binder (1500-2000 cP) contg. furan resin (initial condensation product) and tar in a 2:3 ratio, were mixed in a 60-65:35-40 ratio, the mixt. was extruded when fired to give electrodes which show elec. resistance 2.1 m OMEGA-cm, bending strength 650 kg/cm2, apparent d. 1.75, air permeability 5 ml/min., and complete resistance to penetration by electrolytes. In contrast, an electrode prepd in the conventional manner with pitch tar as the binder, showed for the corresponding properties, values of 2.8, 500, 1.65, 10, and penetration by electrolytes.
Shaped carbon products are obtained by mixing powd. C with the initial condensation products of furan-modified resin, moulding, and firing. These materials are useful as electrodes for dry cells. In an example, a mixt. of graphite 90% &lt;300 mesh) and binder (35-40%, furan-phenol resin initial condensation product, 1000-2000 cP) was extruded, then fired to give a product with elec. resistance 1.6 m OMEGA-cm, bending strength 900 kg/cm2, apparent d. 1.89, air permeability zero ml/min. (at 4 kg/cm2 air pressure), and no penetration by NH4Cl soln. A material prepd. in a conventional manner with pitch tar gave for corresponding properties 2.3, 500, 1.65, 10, and showed some penetration by NH4Cl soln.
Shaped carbon products are obtained by blending C powder with the initial condensation product of furan resin, moulding the mixt., and firing. Electrodes for dry cells can be obtained in this manner. In an example, graphite powder (90% &lt;300 mesh) and binder (initial condensation product between furfural and furfuryl alc. 1000-2000 cP) mixed in a 60-65:35-40 ratio was extruded at room temp., then fired to give a C electrode. This material showed elec. resistance 1.5 m OMEGA-cm., bending strength 1000 kg/cm2, apparent d. 1.93, air permeability zero ml/min. (tested against 4 kg/cm2 air pressure), and no penetration by electrolyte (NH4Cl soln. contg. surfactant at 2 kg/cm2 for 2 min). In contrast, an electrode prepd. in the conventional manner with pitch tar sh owed, for the corresponding properties, values of 2.8, 500, 1.65, 10 and penetration by NH4Cl soln.
Flat unit cells made of acid- and oxidn.-resistant frames and poly(tetrafluoroethylene (I) diaphragm windows are used as either anodic or cathodic chambers of an electrolytic cell for regeneration of spent electroplating baths in which the soln. to be treated is fed into the anodic chambers, while an appropriate electrolyte soln. is fed into the cathodic chamber. Optionally, the diaphragm windows are supported by sandwiching them between perforated thin plates. The use of an (Ie diaphgram makes the unit cell very compact and thus gives an electrolytic cell with short inter electrode distance, which is esp. useful for regenerating Cr electroplating solns.
Gas electrode comprises a porous substrate, a catalyst material layer and an upper surface to be presented to the electrolyte of vinyl or acrylic (deriv) polymer. The latter is so arranged that when the electrolyte is alkaline the layer is formed from a polymeric alcohol or carboxylic acid and where the electrolyte is acidic the layer is formed from a polymeric amine or amide. Excess air press. and the use of strongly hydrophobic matls are not needed.
In the continuous prodn. of the grid plates for Pb accumulators by mixing Pb oxide dust (Pb + PbO) to a paste successively with water and H2SO4, cooling and pressing into the grid spaces, the dust is ground before mixing to increase and equalise its surface activity and the paste is pressed through a die of a suitable size and shape in the form of a thin, wide, cohesive strip, whilst the grid is passed to or under this strip, which is pressed into the spaces. The paste pref. is extruded through a wide slit die and pressed into the grid spaces by rolling. The water used for mixing can also contain additives needed for negative grid plates, e.g. BaSO4, C black, lignin derivs. and/or storage stabilisers. The mixt. can be stabilised by adding high-mol. water-soluble polyethylene oxide, pref. in a amt. of 0.05-0.5%, before adding the water. Grinding and mixing are carried out in a 2-shaft mixer-kneader-extruder, with 2 adjacent worm shafts, turning in the same direction, in an 8-shaped twin-screw housing. This continuous pasting process gives good homogeneity and uniformity in wt. and dimensions, so that the plates have reproducible physical and chemical properties. The proces is simple and suitable for mass prodn. and the closed construction reduces the lead dust level in the factory.
An absorbent separator sheet between the anode and cathode depolariser mix of an electric battery having an aq. electrolyte soln. consists of 10-30 wt.% elastomeric resin binder forming a continuous matrix blended with a gelling agent for absorbing and retaining electrolyte, the resin and gelling agent being dry blended with the gelling agent ungelled and formed into a film 3-15 mil thick. The separator absorbs and immobilises large amts. of electrolyte, uniformly wetting the anode to prevent corrosion, esp. of Zn anodes. Absorption of discharge prods. helps to prevent leakage. Such separators are useful in conventional LECLANCHE prim. batteries.
A suspension of water-proof binder consisting of catalyst and fluorine-contg. polymers is formed into a paste with a surfactant consisting of n-octyl or n-nonyl phenoxy-polyethoxyl-ethanol coated on a collector and heated, at about the softening point of the binder, to form a catalyst layer on the collector.
A microporous body is formed from a compsn. comprising synthetic resin, solvent and non-solvent, and the microporous body is then heated, while it contains a part of the solvent and/or the non-solvent, by irradiation with electromagnetic waves to strengthen the bond between the synthetic resin molecules from which the microporous body is formed. The resin is e.g. polystyrene. The microporous matls. can be used as separators for batteries, diaphragms for electrolytic cells, etc. Improved mechanical strength and chemical stability are obtd.
ZrO2, ThO2, beta-alumina, alk. earth oxides, rare earth oxide, or transition metal oxide solid electrolytes for fuel cells and chem. potential monitors are prepd. by impregnating org. polymers with appropriate amts. of metal salt solns., drying and thermally decompg. metal salt-impregnated polymers, and press-moulding and sintering the resultant powder. The homogeneous electrolytes have ion cond. and high d.
Chloride ions corroding accumulator electrodes are completely removed by washing a sintered separator with hot water (95-100 degrees C). The separator is then rendered hydrophilic by treatment with a surfactant. In an example, PVC powder is sintered at 200 degrees C, then washed with boiling water for 1-2 mins., treated with a surfactant soln., and dried at 65 degrees C. The porosity of the product is 49-50%; the max. pore dia. is 25-30 mu; the tensile strength is 35-50 kg/cm2. Chloride ions are absent.
Mould for injection moulding a battery container comprises a die portion into which projects a core portion having a number of slabs, to form a multi cell mould cavity. Locating devices, one for each slab, are situated adjacent the centre of the bottom of the cell and comprise co-operating male and female members, respectively attached to one mould portion and a member which is movable relative the other mould portion, with the latter member moved during a moulding operation from a position in which the male and female members co-operate to locate the slabs in the die cavity, and a retracted position. An injection nozzle is formed in one of the co-operating locating members. With the male and female members in the co-operating position the slabs are accurately located to enable moulding a multi cell container with uniform wall portions, the co-operating members however forming holes in the bottom of the cells. In the retracted position the holes are filled to complete the container.
Zn electrodes for rechargeable Zn elements have a coating of a hardened colloidally dispersed emulsion. This coating pref. contains negative excess charges and is gas-permeable. It consists of natural or synthetic latex (e.g. styrene-butadiene, styrene-acrylate) and can be applied by electrophoresis, spraying, dipping or spreading. Before coating with latex emulsion, an insulating layer is applied using a rubber soln. in benzene. The electrodes can also contain electrolytic Cu to increase the conductivity and PTFE as binder, the electrode pref. being produced by pressing a mixt. of 73.4% ZnO, 18.35% electrolytic Cu, 3.67% HgO and 4.58% PTFE onto a Cu mesh and forming electrochemically. The process prevents dendrite formation and allows repeated charging in the usual way for accumulators. The charge capacity is almost the same as that of conventional electrodes.
A thin film separator for a cell is mfd. by depositing a synthetic resin soln. of synthetic resin matl. such as PVC. chloride, polystyrene, polyfluorovinylidene, vinylidene-acrylonitrile copolymer or vinylidene-chloride - vinyl chloride copolymer and a water-miscible solvent on a porous substrate; contacting the deposited synthetic resin with a solvent which does not dissolve the synthetic resin; and vaporising a volatile matl. in the resin to form pores.
An alkaline galvanic cell comprises a container having (a) an anode of alkaline electrolyte absorbed in cross-linked polyacrylamide particles to form electrolyte nuggets with electrolyte-wetted Zn particles contacting each other and the nuggets and (b) a venting orifice defining a conduit for gas passage from the anode chamber having a press. movable resealable venting valve biased in a sealing position at its top and a gas-permeable, liq-impermeable membrane at its bottom.
A composite anode for a galvanic cell comprises (a) alkaline electrolyte absorbed in a cross-linked polyacrylamide to form electrolyte nuggets and (b) zinc particles wetted with electrolyte and distributed through the composite anode to contact each other and the electrolyte nuggets. The anode expands only slightly due to gas evolution. The accessible Zn powder combines with O2 generated on overcharge, with dissoln. of resulting ZnO preventing H2 evolution, thus limiting cell voltage and preventing gas press. build up. In spite of the void structure and uncompressed powder, amperage is about the same as conventional anodes on initial prepn. and about 65% after 6 mths. at 45 degrees C. storage.
Process comprises mixing vinyl monomers, a polymn. starting initiator and a polymn. accelerator with an electrolyte, the vinyl monomers consisting of 2 cpds. selected from acrylamide, acrylic acid and methacrylic acid amide, to form a pasty electrolyte; mixing a natural paste with the pasty electrolyte to form an electrolytic paste; injecting the electrolytic paste into a zinc can; and heating it to form an electrolytic paste layer.
Ni-Zn accumulator consists of a laminate of a separator between a Zn and a Ni electrode and has an alkali soln. as electrolyte. The Zn electrode is produced by pressing a mixt. of 60-99.5, pref. 70-98 wt. % finely-divided Zn and/or ZnO, 40-0.5 pref. 30-2 wt. % finely-divided Bi, Cd, Tl, Sn, Se, Te, In, Pb, their oxides or hydroxides and/or Ca(OH)2 and a binder onto a substrate, whilst the separator is produced by coating an alkali-resistant porous substrate with a mixt. of polyvinyl alcohol and a cpd. of the B oxide series of a metal oxide with a low solubility in alkali soln. and drying. The separator pref. projects beyond both ends of the Zn and Ni electrodes. The accumulator has a greatly improved charge/discharge cycle life.
An accumulator cell has a housing and a cover made of polystyrene. The bottom of the housing has parallel or concentric ribs and the gaps between them are in turn filled with lead dioxide and lead or copper. The active filling reaches to just below the top of the ribs and is covered by a thickened electrolyte. No sludge can be deposited from the active mass. No negative grid is required, thus saving 25% of lead metal. No. grid edge is needed for the positive electrode, the separators are saved. The mfr. is easily automated. Discharge produces a convective mixing of the acid. The use of copper instead of lead has many advantages. The cell may be used as an emergency battery for lighting, portable TV sets and pocket calculators, toy motor cars, electric motor cars.
A plastics battery case and cover are heat sealed together by spacing them apart and introducing between them a radiant heater to soften their facing surfaces. The case and cover are then moved into abutment to effect the desired seal. The position of the radiant heater is adjustable relative to the case and cover to ensure that both are heated to the required degree despite differences in colour and/or compsn. The sealing operation may be effected by appts. comprising a vacuum platen to raise the cover clear to the case and to press it against the case after application of heat and a reciprocable electrically heated platen, the plane of reciprocation of which is adjustable. It is preferable that the vacuum platen is coolable to ensure a quick bond.
A dry battery has a solvent type binding agent coated between package members covering the unit cells, to render them liq. tight. The binding agent consits of polyethylene or an ethylene copolymsd. with nitrile rubber.
A dry battery has a layer coating on an upper surface of a cathode mixt. and an electrolyte layer, the coating layer consisting of wax contg. thermally adhesive resin, the resin being composed of copolymer made of ethylene and acrylonitrile, nitrile rubber, polyamide resin and ester of hydro-rosin.
The cell comprises a zinc anode, a cathode, a cathodic mixt., an electrolytic paste layer, and an ion-permeable separator interposed between the cathodic mixt. and the paste layer adjacent to the zinc anode. The ion-permeable separator consists of derivs. of vinyl acetate 10 to 30% of which are denatured by crotonic acid and in which a carboxyl gp. of crotonic acid forms zinc salts. The separator prevents migration of electrolytic paste in preservation and in discharging and prevents expansion of the cathodic mixt. in discharging.
A plastic container is formed by extruding a tube of thermoplastic material onto a mandresl such that a portion at the upper end of the tube extends freely above the upper end of the mandrel. This portion is then heated by pref. directing hot air from nozzles onto the outside of it then moulded to produce a neck whilst the upper extremity of the tube is held in an upper support hood. The container is used for liquids, powders, pills or as cover for electric batteries. The neck of the container is simply and cheaply produced.
Positive electrodes for primary cells contg. alkaline electrolyte are made by moulding mixts. of MnO2, graphite and a non-soluble, non-swelling polymer dispersed in a hydrophilic medium as binder.    Electrodes are dimensionally stable and do not swell in contact with electrolyte, which is readily absorbed due to absence of a surface skin of polymer. No toxic or expensive solvents are used, and the components of the mixt. do not separate on storage.    The dispersion pref. contains 3-60 (5-25)% organic polymer, and is added in amount sufficient to give 0.5-5 (0.5-2)% polymer and 1-10% water, which is the pref. medium, in the mixt. Suitable polymers are polystyrene, polyolefins, opt. fluorinated, or pref. polyisobutylene.
An electrode bearing electrically conductive and ionically non-conductive plastics strip is made by casting a solution of a solvent, a resin and a conductive filler to form the plastics strip and contacting the strip with an electrode mixture comprising a solvent based conductive resin and an electrode material. Action of the solvents on the strip and the electrode mixture cause the intemiate mixing of the strip and material at their surfaces of contact to produce, upon subsequent removal of the solvent, an extremely good bond between the strip and the mixture coating. The strip is of particular use as a carrier strip in a duplex electrode cell. Pref. the resins are rendered conductive by a carbon filler. The plastics used must be compatible with the electrolyte being used and may range from a polyacrylate, a polyvinyl halide, a polyvinylidene chloride, a polyacrylonitrile for moderately alkaline electrolytes to PVC or a polyolefin such as polyethylene or polyisobutylene for strong alkaline electrolytes. For acidic electrolytes copolymers of vinyl chloride and vinylidene chloride may be used. Conventional solvents for these materials, for example, acetone ethyl alcohol, ketones etc. can be used.
The fuel cell has fuel chamber frames, electrode frames and air chamber frames fastened together with metal bolts coated with a PTFE layer.
The separator comprises an acid-resistant synthetic resin frame or matrix, the interstices of which are filled with a mixt. of (synthetic) rubber and an ion exchange resin.
A member for indicating the specific gravity in a lead/acid battery comprises a body of a butadiene/styrene rubber filled with a specific amount of china clay to give it a desired specific gravity. In use, a plurality of members, e.g. balls, are used, each member having a specific gravity determined by its china clay content and a colour different from the others. By observing the colours that float and those that sink, the specific gravity of the acid electrolyte can be easily determined. The members can be given accurate specific gravities which will not alter during extended periods of use.
Separator for electrical accumulators, esp. lead accumulators, consists of a pocket contg. a parallelepipedic plate of the accumulator, whose faces are formed by two microporous, e.g. PVC, sheets that are electrically insulating and resistant to electrolyte, these sheets being joined by a flat strip that is applied to their edges, and is rigid, electrically insulating, and resistant to the electrolyte. The separator maintains the accumulator plates in the correct position relative to each other, and protects them efficiently while permitting the free circulation of electrolyte. The flat strip pref. consists of a mixt. of an ethylene copolymer and synthetic acrylic rubber. The strip is applied to the edges in a plastic state, and is solidified by cooling.
A separator for a lead storage battery is made by pressing a mixed malt. with rollers, the mixed matl. essentially consisting of a rubber material or a synthetic resin and an ion exchange resin and contg. &gt;60 wt. % of the ion exchange resin w. r. t. all ingredients.
The storage battery is formed in a container. The cover is fixed to the container with a bonding agent, the bonding agent being treated to shorten its hardening time and to stabilise its chemical props. The bonding agent, which can be epoxy resin, (un)satd. polyester resin, modified polyester resin, polyurethane resin, polyamide resin or phenol resin, is vibrated with a ultrasonic vibration device at 28-800 KHZ to shorten the hardening time, the vibration time being 15-30 secs. The container and the cover are made from polystyrene, copolymer of acrylonitrile and styrene, copolymer of acrylonitrile-butadiene-styrene, polyethylene, polypropylene copolymer of polyethylene and polypropylene, polyvinyl chloride, polyamide, acrylic acid resin or polyester.
A dry, cell battery has a cylindrical separator of paper coated with a polyvinylalcohol film to separate the generating element from the zinc cathodic can.
Articles are treated with a molten coating material which is a hot melt thermoplastic material applied to the underside of a heat shrinkable flexible film. Application of such coatings is effected by clamping the support film, fusing the coating, and releasing the clamps to allow the support to contract about the target article before the melt layer chills sufficiently to become non adhesive. Esp. used for enclosing and sealing the ends of electric batteries against loss of water generated within the battery body during use. The close-fitting, long lasting adhesive seal between the support sleeve and the clad element eliminates the need for independent mechanical or elastomeric seal profiles etc.
Water-soluble nonionic thickener 0.01-3 (0.05-0.6) % is included in a catalytic paste of 3-55% elemental C material, particle size &lt;25u 2-10% hydrophobic binder 0.6-4% catalyst, and 30-70% water. The thickener is sufficiently alkali resistant not to form prods. poisoning the electrolyte and produces, in 2% aq. soln. a viscosity of at least 100 cps. The catalytic compsn. can be worked into a plaque rapidly, e.g. 15 min, by hand, 1 min. with automatic blade compared with 1-1 1/2 hrs. for conventional pastes worked into a 1 ft2 plaque and it does not break the plaque fibres or force water from the plaque at normal working pressures. Also the plaque has improved polarisation characteristics.
Galvanic cell comprising a depolariser mix. a Zn anode, an electronic separator between anode and depolariser and an aq. electrolyte in ionic contact with anode and depolariser, includes a polymerised dimethyl diallyl quaternary ammonium salt from polymerised dimethyl diallyl ammonium chloride and copolymerised dimethyl diallyl ammonium chloride with (i) acrylamide, (ii) diacetone acrylamide or (iii) dodecyl ammonium chloride in contact with the electrolyte within the container. Alternatively the inhibitor is vinyl benzyl-trimethyl ammonium chloride. The additive acts as a corrosion inhibitor reducing loss of capacity with age and increasing the performance of the cell even when new, by providing an increase in cell voltage under heavy drain. The effect is about equiv. to that of Hg, so that expensive polluting Hg can be omitted, although max. improvement is achieved when Hg is also included.
A liq. fuel cell comprises an oxidn. electrode, a fuel electrode and a caustic alkali electrolyte dissolving a fuel for generating a gas by discharge reaction. The oxidn. and fuel electrodes have a porous thin film at their opposing faces and are closely adhered through a separator. The porous thin film is composed of an electrolyte resisting insulating powder and electrolyte resisting synthetic resin.
A flat heating element comprises a solid battery covered with (i) heat- and electrolyte-resistant synthetic resin film (II) a sheet resistor, and (III) an outer layer of the synthetic resin. Current generated in the solid battery flows into the resistor to generate heat when the battery and the resistor are connected. The battery consists of a cathode of MnO2, an anode of zinc plate and a separator impregnated with electrolyte.
The element comprises a solid battery consisting of a mixt. of cathode of manganese dioxide powder and conductive carbon powder, an anode of fibres and fine zinc powder on the fibres and microcapsules contg. electrolyte of Al ammonium chloride soln. The mixt. is covered with synthetic resin. When the microcapsules are broken by the pressure applied to the capsules, the electrolyte contacts the cathode and the anode to short-circuit them and heat is generated.
Ion-exchange polymers in which 40% of the ion-exchange sites, at least on the surface region, consist of N-monosubstd. sulphonamido gps. or their salts, attached to C atoms carrying 1 F atom. The polymers are used as membranes in electrolytic cells, esp. chlorine-alkali cells, to suppress transport of anions, e.g. OH. Use of an amine instead of ammonia to form the ion-exchange sites gives much shorter reaction times - around 1 min. instead of several hrs., and makes continuous processing possible. Current yields are increased to 90%, e.g. an increase of 4-5% by use of methylamine instead of ammonia, and lower operating voltages may be used.
A battery separator is made by (a) polymersing an aqueous vinyl chloride emulsion to form an aq. resin emulsion contg. latex particles of dia. 0.01-2.0 mu and 10-60 wt.% solids, (b) mixing the resin wht a diatomaceous earth filler contg. particles of size 2-150 mu so that the filler constitutes 10-40 wt. % of the total solids including the filler contained therein, (c) spray drying the prod. of (b); (d) shaping the prod. of (c) into a sheet profile and sintering this to produce a rigid sheet of volume porosity 30-70% and a pore size 20-40 mu. The battery separator has increased strength, optimum volume porosity, pore size, electrical resistance and permeability and is simple and economical to make. To process is also suitable for mfr. of material for liquid and gas filtration, fluidisation of powders, pneumatic silencing and humidifiers.
In a lead accumulator of the paste type, consisting of unit cells in a layer construction, each comprising a positive plate (I) coated on both surfaces with an active anode material (II), a fibrous structure (III) on each side of (I) and a negative plate (IV) on each (III), there is a separator (V) between (III) and (IV) on both sides of (I), consisting of a paper-like sheet with an open, microporous structure over its entire surface and contg. is not &lt;70 wt. % phenolic resin fibres with fibre dia. is not &gt;5, pref. is not &gt;3 mu, produced by melt spinning and curing a novolak resin. In the fibres, pref. is not &lt;60% of the phenolic OH gps. of the resin are blocked. The accumulator has greatly improved electrical capacity and long operating life. The fibres with (partly) blocked OH gps. have improved acid and oxidn resistance, allowing the prodn. of very compact accumulators with greatly improved cell capacity and high power.
In the parent patent a covering for the reactive material of a lead battery is made by hot or cold pressing sintered micropowders of oxygen/acid-resistant polymer into the desired microporous shape. In the addn., 1-20 pref. 10-15 wt. % of a micro-powdered polymethacrylic acid ester is added to the polymer granulat before moulding. The higher the additive content in the basic polymer the higher is the heat resistance, up to 90 degrees C and over. In place of sintering the granulate, the mixt. can also be combined by an oxygen/acid-resistant adhesive.
Oxygen electrode for alkaline galvanic elements consists of loosely packed, hydrophobised active C with a specific surface area &gt;500 m2/g in a container and cover of water-repellent plastics reinforced with metal inserts and with porous parts, which have a microporous separator on the side towards the electrolyte and a metallic material on the side towards the active C. The porous parts pref. consist of polyamide, polyethylene or polypropylene non-woven mat, whilst the metal consists of or contains Ag and is deposited on the porous parts in vacuo. The vol. of metal is (pref. much) less than 40 vol. % w.r.t. the porous part. The microporous separator consists of very finely ground cellulosic material, pretreated with an oxidant.
Graphite electrodes are fitted in the picture frame type leakage-current inhibiting plates made of elec. insulating materials, and the electrodes and thin spacers are pressed together so that the spacers are in tight contact with the leakage-current inhibiting frames to form a multi-electrode electrolytic cell. The leakage currents are effectively prevented by using the frames, and replacement of the consumed electrode is simplified because each electrode is not permanently affixed to adjacent electrodes. The electrolysis cell is esp. useful for brine electrolysis.
Zinc chloride dry cell has a separator comprising 5-30 (8-25)% reticulated polyacrylamide and 70-95 (75-92) wt. % of a mixt. of talc and starch, esp. maize starch in a ratio 0.2 to 6.0 pts. talc. per pts. of starch. The separator remains uniformly moist.
A gas diffusion electrode for an electrochemical cell comprises a metal net, a corrosion resistant, electrolyte and gas-impervious graphite-foam coating on the net, sunken canals in the coating for conducting electrolyte, a porous catalyzing layer conforming with the net and contacting the coating, and an insulating coating on the graphite foam coating. System permits the electrodes to be connected in series without short-circuiting. Sealing is accomplished merely by laying the electrodes together.
A flat alkaline cell comprises a pair of flat electrodes and an electrolyte-contg. porous separator enclosed in a sealed, liq. impervious, plastic film envelope having an opening in one wall which has internal and external flat current collectors adhered to it by a sealant which is nonwettable by the electrolyte, the internal collector being connected to one of the electrodes and being connected through the opening to the external collector. Appts. has increased resistance to electrolyte leakages, and can be assembled rapidly and economically.
The catalyst is carried on asbestos fabric located in the stopper. The fabric is pref. in the form of a rolled-up spiral or, alternatively, 1 cylinder, with an inter. layer contg. a second catalyst for oxidn. of antimony hydride. The asbestos insert is easy to make and to use, the catalyst being employed to reduce or eliminate the re-filling of the battery with distilled water, by causing the H2 and O2 to recombine.
A negative Zn electrode comprises (a) finely divided Zn particles; (b) 0.1-20 wt. % ZnO; (c) alkaline electrolyte; (d) 0.05-10 wt. % electrolyte-durable gel-forming matl; (e) 0.1-10 wt. % boric acid, its salts of B2o3; (f) 0.1-20 wt. % electrolyte-stable inorganic oxide or hydroxide of a metal less noble than Zn; and (g) 0.1-10 wt. % pulverised cellulose. The electrode is assembled into a cell with a positive electrode and a separator, the alkaline electrolyte being present in the negative electrode. The cells exhibit longer discharge times at high discharge rates than reference cells in which negative electrodes contain no ZnO or electrolyte e.g. 76 min. through 3 omega c.f. 54 min., and the capacity loss on storage was less than about half that of the reference cell. At -10 degrees C., the ratio of discharge times for an inventive and a reference cell through a 10 omega load is 1.45:1.
A pressed Cd negative electrode comprises a substrate, with a compressed mixt. of (a) stabilised spherical 3-12mu Cd-metal particles, formed by condensing Cd-metal vapours in the presence of O2; (b) 0.01-5 (0.1-5) wt. % Ni(OH)2 powder; (c) a Cd-cpd. powder of CdO, Cd(OH)2 and mixts.; and (d) a binder. The negative electrode, a positive electrode and an alkali electrolyte are contained in an alkali-resistant container having 1 insulated terminal. Inclusion of 1% Ni (OH)2 yields a 35% increase in capacity retention after 70 dyas on overcharge at 120 ma., 120 degrees F. The Cd-metal particles are pref. stabilised with CdO and comprise 34 wt.% mixt. The Cd-cpd. pref. has a particle size of ca 1mu and comprises 60-98 wt.% powder mixt. The binder is an unsintered fluorocarbon binder.
The battery contains a gas absorbent made up of Carbon black, catalyst e.g. Au, Pd etc. and PTFE in a porous chamber to absorb any gas generated. The absorbent has high water-repellent prop. and is in powdered form.
A dry cell electric battery is encased in a plastic casing onto which is bonded an outer layer of metal foil or metal foil laminate. Particularly for circumferentially encased cylindrical or prismatic dry cells. The merits of a plastic casing as compared with conventional steel jacket, are combined with the strengthening and reinforcing properties of the metal foil. The foil accepts and retains printed indentification or inscription better than the plastic alone and does not attract dust.
Positive electrodes for primary cells are produced by (a) hydrophobising active carbon with a film of polyethylsiloxane; (b) forming a mixt. of ca. 30 wt. % of a Mn-bearing mineral, ca. 20 wt. % carbon black and ca. 50 wt. % of the hydrophobised active carbon; (c treating the mixt. with 1 pt. wt. aq. alkali soln. per 5 pts. wt. of the mixt.; and (d) stirring and pressing the resulting mass. The electrodes can be used in air-depolarised batteries for operating electronic equipment. Hydrophobising the active carbon as above protects it from atmospheric humidity whilst still allowing access to air, thus improving the performance of the cell after long periods of storage.
Galvanic prim. element with alkaline electrolyte, negative Zn electrode and positive MnO2 electrode has a positive electrode plate consisting of expanded Ni metal coated with or covered with a film of a binder and a conductor onto which MnO2 (pref. contg. 10-30 wt. % graphite and up to 5 wt.% binder, e.g. a CH2:CCl2 copolymer) is pressed. The binder can be polyurethane, polypropylene, PTFE or esp. polyisobutylene and the conductor metal (Ni or Cu) flake or esp. graphite. The cell has a stable potential at high current load and a mass utilisation of over 50%. the coating is elastic, protects the expanded Ni from oxidn. and ensures satisfactory contact between the support and the active compsn.
In a primary battery cell all the electrolyte is incorporated in the depolarising mass, the mass comprising MnO2 graphite and/or acetylene black and opt. ZnO, with NH4Cl2 and/or ZnCl2 as electrolyte. The electrolyte content of the mass is 25%, and at least part of the surface of the constituent solids have been treated with 0.02-0.5 wt. % of a water repellent. Storage life of the battery is greatly improved, approaching that of the depolarising mas alone. There is no tendency for the electrolyte to soak into the depolarising mass or otherwise to move from the location in which is is put when the cell is first made up.
Electrode assembly comprises an anode, separator, glass mat and cathode which is coated externally with an aq. or alcoholic suspension of polymer particles 5-50 u in size. The coated assembly is heated to form a layer of insulating matl.
The lead storage battery comprises a separator comprising a separator body and a gauze like fabric impregnated with starch or synthetic resin fixed to the separator body, the fabric consisting of polyester or polyacrylic fibre. The separator is arranged so that the gauze like fabric faces a cathode plate. In the fabrication of a lead storage battery, the separator is arranged between an anode plate and a cathode plate (without a glass mat) in which the gauze like fabric is in contact with the cathode plate. By using the separator, the distance between the anode and cathode plates can be reduced and the volume of the battery can be reduced. Since the separator suppresses the falling off of the cathode active matl, the service life can be improved.
Self-supporting, polyurethane accumulator or storage battery case comprises two U-shaped members, having each a base and two sidewalls and an endwall, which are clamped together side by side. The endwalls prevent endwise movement of a battery out of the case. Thus any number of batteries may be combined in a larger unit in which they would be immovable relative to each other, without it being necessary to provide a battery case of a particular construction.
A method of making fibrous non-wovens from thermoplastics (esp. polyolefin or polyamide) consists of smelt-blowing the polymer to form the fibres and combining them to form a mat. This mat contains both relatively fine and relatively coarser fibres. Pref. the fine fibres are made by the smelt blowing process and the coarse fibres by smelt extrusion. The coarse fibres may be extruded through both large and small dia. openings. They may also be smoothed by blowing in a gas stream. In particular, a non-woven may be made comprising fibres which have been wetted to make them hydrophilic and other which are hydrophobic. The latter are randomly distributed in the former. Esp. useful as battery separators, partic, for alkali batteries.
Method comprises of PVA to cadmium oxide powder, kneading, allowing it to coagulate; crushing into particulate cadmium oxide; adhering to a belt-like wire net or porous metal plate, and electrolytically reducing and oxidising the particles of cadmium oxide in an alkaline electrolyte.
The anode consists of a metal net surrounded on both sides by a layer of Al; the outer surface of the Al, i. e. away from the net, are lapped or sand-blasted and anodised on the edges adjacent to the periphery. The metal net is pref. made of Ag and the Al discs pref. contain holes; a membrane of polyvinyl alcohol is used to envelop the finished anode. This anode design avoids the problems arising due to the formation of hydrogen and is used in a bioelectric cell with a working life of ten years suitable e. g. for a heart pacemaker.
A rechargeable alkaline manganese cell comprises a manganese dioxide cathode, an anode consisting of a current collector and a pasty layer of amalgamated zinc, deposited on the collector, and a mat like separator, (made by impregnating a non-woven cellulose fabric with polyvinylalcohol and drying), disposed between the cathode and the anode. The fabric separator is impregnated with 6-8g m-2 PVA and itself is 100-110g m-2. Overchanging the cell produces no gas and subsequent leakage, but zinc dendrites which short circuit the cell.
The parent patent described construction of an electrochemical cell incorporating tubes for forced circulation of an alkaline suspension of a powdered metal (Zn) through a vessel contg. an oxidising atmosphere, where the tube walls were of composite section incorporating layers selectively porous to the oxidising gas, contg. active reagents and including electrically conductive surface layer. This addn. specifies the composition of the chemically active, porous and electrically conductive intermediate layer of the tube wall as comprising 95-50% activated and Ag loaded carbon and 5-50% of a hydrophobic material, specifically PTFE or PCTFE (polychlorotrifluoroethylene).
A silicone-rubber membrane permeable to O2 surrounds the cell and is encased in silicone-rubber at the periphery. Two oxygen cathodes, consisting of catalyst-coated silver nets, are located one on each side of the anode which is housed in a plastic ring forming the electrolyte chambers; the Ag nets are free from catalyst at their edges and are joined over the plastic ring. Membranes are pref. used on the sides of the cathodes facing the anodes to stop the deposition of oxidn. products. This design gives the cell high mechanical stability.
Electrolytic cell with a metal anode, a cathode and an org. water-free electrolyte contg. a dissolved salt current carrier also includes a particulate solid water scavenger incorporated into at least one of the electrodes and electrolyte. Scavenger pref. comprises either a porous sheet of molecular sieve material place between electrolyte and electrodes or is added direct to other components during electrode fabrication, most pref. to the cathode. Method maintains desirable low water content in electrolyte at low cost. Scavenger pref. comprises a natural or synthetic hydrophilic zeolite or cellulose fibre or modified fibre such as anionic crosslinked Na carboxy methyl cellulose.
An electrical lead acid accumulator consists of a positive electrode and a negative electrode. The former contains lead dioxide which is carried by a grid of titanium; the latter contains lead carried by a grid of rustless steel, preferably a nickel-chrome steel. Thin calico sheets with a gel electrolyte contact the positive electrodes and a polyethylene frame. A vinylidene chloride film encloses the assembly. The use of Ti results in a considerably weight reduction. The small distance between PbO2 and electron conductor raises the mass action efficiency from 35-50% to 83-90%. The batter can be completely encapsulated in epoxy resin which represents a design requiring no maintenance.
Hollow plastic articles partic. battery boxes, are moulded using a mould of several adjacent cores and necks, each core being long in relation to its thickness and width. The core necks have spaces between them, and pins and projections which positively support and engage in the core necks. The cores can partially pivot about an axis parallel to the core separations and pref. passing through the core centres. Movement of the mould necks reduces the stress on them.
A flexible porous battery separator for a high energy density battery consist of a flexible porous substrate coated with a film consisting of (i) a major portion of an inorganic separator material, (ii) a minor portion of potassium titanate fibres and (iii) a minor portion of a cured polyphenylene oxide or polysulphone polymer, to bond (i) and (ii) together. The separation is esp. used for Ag/Zn, Ni/Cd and Ag/Cd batteries, and is strong, flexible has good porosity, has high resistance to alkali and can be employed with batteries operating both at ambient and 100-150 degrees C or higher.
A mixt. comprising 30 pts. polyethylene-acrylonitrile copolymer, 20 pts. nitrile rubber, 10 pts. wax, 30 pts. polyamide resin, and 10 pts. of esters of resins is added to pitch, heated to is not &lt;200 degrees C so as to melt the pitch, poured onto the dry cell, and cooled.
Title carbon rods are obtd. by mixing grafted carbon with thermo-setting resins (I) and setting agent; shaping the mixt; and heating the shaped mixt. at a temp. lower than the decompsn. of (I).
A separator, esp. for a dry cell comprising a Zn can with a MnO2-based anode, comprises a fibrous sheet, such as kraft paper, coated with a paste layer of a volatile vehicle, such as methanol or acetone, and starch or ethyl cellulose powders. The coated paper is allowed to dry at room temp. for 4 hrs. The ratio of powder to vehicle is 4:10.
A dry cell with a high discharge current comprises a zinc anode can a carbon rod cathode placed in the centre of the cell, a cathode mixture contg. manganese dioxide depolariser and an electrolyte between the anode can and the cathode mixture. Electrolyte firmly adheres to anode can, has a high hygroscopicity and comprises a polymsd. paste layer prepd. by (1) adding the electrolyte, 3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro-5, 5-undecane cross-linking agent and a polymerising accelerator to the soln. of acrylic amide and (2) placing the soln. between the anode can and the cathode mixture to polymerise the acrylic amide paste layer.
The battery comprises an anode can of Zn, a C rod cathode a cathode mixt. consisting mainly of MnO2 depolariser. A separator between the anode and cathode mixt. is prepd. by mixing a water swollen paste e.g. methyl cellulose, starch, with a heat fusible synthetic resin powder e.g. polyvinyl acetate, polyethylene and heating, then spreading the mixt. on a PVA layer. The battery jar is sealed with a wax sealing member.
The silver chloride (AgCl) battery comprises a AgCl cathode electrolyte and a magnesium or zinc anode plate separated by a corrugated plastics sheet of PVC, polyamide, polyethylene, etc, contg. perforations of 2-5 mm dia. The AgCl is fused and rolled into &lt;0.3 mm plates and has the surface reduced to metallic Ag.
A mercury oxide cathode activator is inserted in the jar and a fibre sheet impregnated with alkaline electrolyte is inserted and septd. from the cathode activator by a separator. The fibre sheet is further impregnated with porous amalgamated Zn as an anode activator and the jar sealed with a sealing plate of an iron plate, an alkaline- and corrosion-proof metal layer and an anode layer of amalgamated metal in contact with the anode activator. Polyethylene is used as battery packing.
Gas diffusion electrode for a battery cell comprises a mixt. of a conductive metal powder or carbon and a polyhaloethylene. The electrode is made by moulding the mixt. the heat treating the body produced at or above the melting point of the polyhaloethylene. The body is rigid and sound electrical contact can be made to a current collector. The electrode does not have to be made waterproof as in prior art.
A porous diaphragm for use in electrolysis cells is produced by forming a sheet from a mixt. of a synthetic material and particles of a solid additive which can be extracted, arranging the sheet in the cell, and extracting the additive from the sheet within the cell. The cells are partic. for electrolysis of alkali metal chlorides, esp. NaC1. Handling the wet sheet after extn. of the particles is avoided. The synthetic material is esp. polyvinylidene fluoride or polytetrafluoroethylene (PTFE) (pref.). The additive is esp. starch (corn, potato starch), cellulose, cellulose acetate or a water-insol. carbonate (CaCO3), with particle size 5-100 mu; the ratio by wt. of additive: PTFE is 10-0.1 (5-1). The sheet is prepd. from an aq. dispersion of the polymer and the additive, by addn. of a coagulant, drying the coagulate, addn. of an organic lubricant and shaping; or an aq. paste of PTFE, prepd. from a dispersion of PTFE of particle size 0.05-1 mu (0.1-0.2 mu) may be shaped.
The battery contains a cathode, an anode, an electrolyte layer consisting of water contg. microcapsules and solid caustic potash powder, positive and negative lead wires, and a casing including a fibrous matl. After mixts. to construct the cathode, the anode and the electrolyte layer are laminated and moulded at a desired pressure to produce a cell without a casing by means of known techniques. Then aluminium silicate powder is added to a 10% benzene soln. of polystyrene, and the mixt, is dried and pulverised to produce resin powder for making a casing. Nylon fibre with 20-50mu in dia. and 2-5 mm. in length is added to the resin powder together with a binder. Thereafter, the cell is placed in a die, and the space between the cell and the die is filled with such resin powder. Then the resin powder is moulded at 500 kg./cm2 to fabricate a casing.
Silver oxide, powder and a binder are mixed to produce a cathode mixt. Water contg. polyurethane microcapsules, KOH powder and a binder are mixed such that 40% KOH concn. may be obtd. when the cathode mixt. is dissolved therein to make an electrolyte mixt. Zinc powder and a binder are mixed to make an anode mixt. Then these mixts. are limited and moulded at a press. of 100 kg./cm2 to make the cell without the casing. In this case, an electrolyte layer may be formed by the microcapsules and the solid solute, and positive and negative lead wires are buried into the mixts. Thereafter, a resin layer acting as a casing is formed around the cell using a frame to form the battery.
AgCl, C powder and carboxymethylcellulose (CMC) binder are mixed to form a cathode mixt. NaCl soln. contg. NaOH and hexamethylenediamine and adipic acid aq. soln. are dispersed in a mixed solvent of chloroform and cyclohexane to produce micro-capsules 100mu in size by known interfacial polymsn. techniques. The microcapsules are mixed with CMC to form an electrolyte mixt. Mg powder, C powder and CMC are mixed to form an anode mixt. These mixts. are laminated and moulded at 50 kg./cm2 to form a cell around which a frame is attached. Resin is poured into the space between the frame and the cell to form a casing.
Thin microporous fluorocarbon polymer sheets are prepd. by mixing polymer particles and metallic salg particles, forming the mixt. into sheets, and removing the metallic salt particles. Esp. useful as a backing for air electrodes in a metal air battery.
A lightweight electrode (electrode/electrolyte matrix assembly) is made by (a) filling a hydrophilic porous matrix with a volatile fluid substance, pref. water, (b) solidifying the substance within the matrix pores, (c) applying a catalyst layer, pref. Pt black and PTFE, to 1 surface of the matrix and (d) removing the volatile substance, leaving a uniform flat electrode on the matrix surface.
Substrate is made by mixing 85-60 wt. % infusible cured novolak fibre with 15-40 wt. % SiO2 fibre, shaping, and heating in an inert gas to render the novolak fibres conductive. The unit has low cost, has good electrolyte resistance, low ohmic resistance and with an electrocatalyst gives good electrode performance.
Water activated lead battery comprises a battery casing and cover of acid resisting material such as ebonite, styrene resin, etc; the casing and cover being hermetically sealed; anode and cathode plates and respective terminals separator; electrolyte made by absorbing conc H2SO4 in glass wool; a block-shaped electrolyte made by moulding finely divided powdery silica on which conc. H2SO4 is absorbed; a porous casing of PVC, polyethylene, etc. in which the block-shaped electrolyte is disposed; a cylinder having a screw; a cock (for pouring water) which engages with the screw; and a cap plate made of the same material as the casing. The electrolyte body material and the block-shaped electrolyte are arranged on or near the anode and cathode plates, thus an electrolyte having a desired concn. can be obtained when water is poured into the electrolyte body material through the cock. Battery is easy to handle and gives high performance. Battery is ready for use as soon as water has been added.
Starch, water-sol. material e.g. ethyl fibre with 24% etheric value or porosity forming agent e.g. silicic acid, and extending agent e.g. magnesia or Ca(OH)2 are added to natural rubber or synthetic rubber, e.g. styrene-butadiene; the material is mixed by a calendar roll to make a sheet; the sheet is applied to a feed roll to unify the thickness; passed through a tunnel heating furnace; introduced into a prepn. tank including an elutant for the porosity forming agent, to remove the porosity forming agent from the sheet; transferred to a roll to make a porous, spongy sheet which is immersed into a prepn. soln. e.g. styrene-butadiene latex for 20-60 mins, and is coated with such latex; the latex is dried with a tunnel drier; the sheet a is prepd. for a few hrs. in conc. h2SO4 at 30-60 degrees C to form a ion-exchange gp. on the sheet surface; the sheet is washed with water, and then cut to obtain porous separators.
In an example, Kraft ligning is dissolved in 10% aq. NaOH to 8-15 wt. % concn. which is treated with 2-15 % Na2S at 200-315 degrees C and 60-85 kg/cm2 for 1-5 hrs. H2SO4 is added and ppte. obtd. at pH 2-6, recovered as a powder in which 7.5-15% methoxyl gps. have been converted to hydroxyl. The treated lignin is incorporated into conventional anodes.
An electrically conductive coating is formed on one surface of a zinc anode plate by baking an electrically conductive paint coating. The electrically conductive paint is produced by mixing butyral resin, polyvinyl chloride resin, acetylene black and graphite with a solvent of xylole butanol and methyl isobutyl ketone. A separator 4 of kraft paper is stuck on the other surface by a mixt. of polyvinyl alcohol and methyl cellulose. A bonding agent of vinyl chloride-vinyl acetate copolymers is coated over an end surface of the anode a peripheral portion of the electrically conductive coating and a peripheral portion of the separator A cathode ixt. is disposed on the separator. A thermo-constricting tube of vinyl chloride-vinyl acetate copolymers is covered over the cathode mixt. the end surface of the anode plate, and peripheral portion of the electrically conductive coating and the peripheral portion of the separator. A lower end of the tube is adhesively bonded to the peripheral -portion of the electrically conductive coating An upper end of the tube is thermally constricted. A peripheral portion of the film reacts with the bonding agent to prepare high polymers having water-holding props.
Carbon is mixed with an electrical conductive agent and liq. polyamide resin diluted with a reactive diluent which serves as a setting agent and contains &gt;2 epoxy gps. per molecule and the resulting mixt painted onto a Zn plate to form an electrically conductive coating. The coated plate can be used as a carbon coupling electrode plate in a layer built dry battery.
Solar cell has over its light-sensitive layer a protecting, translucent coating or covering of flatting paint providing a semi-gloss effect. Pref. the flatting paint is an epoxy, silicon or nitrocellulose paint contg. admixed, pulmerised silicic acid as opacifier. The cell thus has a satisfactory appearance.
Galvanic cell comprises a shallow cylindrical casing with a perforated base and contains a prefabricated cathodic sub assembly sepd. by a polyacrylic acid gel from an anodic suspension retained by metallic caps set in an electrically insulating collar. The cathode also has an insulating mounting. A hydrophogic polymer film covers a catalytic layer incorporated in the cathode. Electrode interface may contain an additional separator layer of "Pellon" or "Webril" to seal the anode compartment against liq. losses. Design is compact with a high cell surface/volume ratio, and the well is sealed against loss of the anodic electrolyte.
A batter element comprises positively and negatively charged plates arranged in series, each sepd. by an electrolytically permeable separator. The edges of the separators are tightly connected together by common walls, on at least 2 sides, so forming a packet of pockets for the plates. The walls consist of an opt. fibre-reinforced carrier of polyester foil or polyester fleece coated with a melt adhesive based on polyethylene (I), (I)/wax or (I)/PVAc. Used in mfr. of starter or indl. batteries requiring little servicing. Little risk of short-circuiting and over-charging.
The core of the accumulator plates, esp. for lead accumulators consists of a plastics framework sheathed with a thin (porous) Pb layer. The latter may be applied either by a dip-coating method or by cold-pressing the lead sheath onto the plastics framework. The principle is also applicable to Ni-Cd accumulators.
A bond material is injected in heated, plasticized state between rigid components of an electric storage battery, capable of withstanding sudden temp. changes, and forming a leakproof seal. The material is a thermoplastic substance rendered expandable by addition of a foaming agent, thus providing a flexible seal mass of a density as low as 0.45 g/cc. and having close cells and forming a stress-free tight bond between components. The thermoplastic is suitably the same material as used to mfr. the casing.
The elastomeric seal, for use in an electrolytic cell of the diaphragm type for the prodn. of chlorine, comprises a blend of (a) natural rubber or cis 1, 4-polyisoprene and (b) halogenated butyl rubber, EP terpolymer rubber, acrylonitrile butadiene copolymer, SBR and/or chlorosulphonated polyethylene, wt. ratio of (a):(b) being 35-65/65-35. The elastomer blend provides a seal between an anode connected to a riser and conductive metal cell base and between the base and a brine soln. contained in a cell can. (a) softens and (b) hardens under the influence of heat i.e. 200 degrees F. during cell operation and the seal remains flexible without cracking at the junction between the anode risers and the cell base so that leakage of the brine soln. onto the cell base does not occur.
Powd. Ca(OH)2 is mixed with aqs. polyvinyl alcohol (I), dried, crushed and sieved. Alternatively, granular Ca(OH)2 is treated with I, used in a 0.1-10% amount. The product did not collapse in regeneration of KOH from K2KnO2.
A vulcanisable compsn. comprises (i) 6-20 wt. % styrene-butadiene copolymer rubber contg. 5-30 wt. % styrene; (ii) 50-80 wt. % finely divided inert filler of particle size &lt;80u and selected from coal, talc and hard rubber dust; and (iii) 2-8 wt. % of a resin of a styrene-butadiene copolymer contg. 70-90 wt.% styrene and having a softening pt. of 150-250 degrees F to provide in the cured compsn. a tensile strength of is not &lt;670 psi at room temp. and an impact resistance of is not &lt;3 inches (with a 21b ball) at 0 degrees F and based on the rubber (a) ca. 30-70 wt. % of a processing oil of viscosity ca. 40-180 SUS at 210 degrees F (b) ca 40-100 wt. % of an activator selected from alkaline earth hydroxides or carbonates. and (c) 4-12 wt. % sulphur. The compsn. is useful for mfr. of a thin-walled container with 1 inner compartment(s) having walls of thickness is not &lt;0.2 inches, which is useful as an electric storage battery box.
A porous electrode having an electrically conductive electrocatalytically active layer and a contiguous gas permeable hydrophobic layer is made by (i) filtering a first suspension of PTFE power in propanol-1, isopropanol, butanol or dichloromethane, and withdrawing liquid from it to form a first porous layer comprising a matted and damp PTFE filter cake, (ii) placing a metal screen on the filter cake, (iii) filtering a second suspension of carbon powder, graphite fibres, and PTFE power in (iso)propanol, butanol or dichloromethane, by withdrawing liquid from it through the screen and the first layer, and (iv) heating the two layer structure to 330 degrees C. The electrode is esp. useful in fuel cells, and the method of mfr. ensures that the electrode is comprised of two discrete layers without encroachment of either layer physically into the other.
If a binder e. g. PTFE is added during paste mixing, the paste sets either in the mixer, or in the pasting machine bunker. Addition of aqs. suspension of PTFE to the above buker, or treatment of finished plates does not produce satisfactory results. Now it is proposed to apply the binder to the grids before pasting and at a temp. of 15-30 degrees C. This can be done by various methods, e.g. by immersion of grids into the suspension, or by spraying. The treated grids are fed to the pasting machine, where the paste and binder are mixed together during pasting; the plastic is polymerised during plate drying after pasting.
Cover sheath for the active material of an electrical accumulator consists of a combination of (I) a porous layer of nonwoven textile contacting the active material, and (II) an external support for (I) consisting of monofilaments or highly twisted continuous fibres. Both (I) and (II) pref. consist of synthetic fibres. Sheath combines mechanical strength with satisfactory porosity.
P2O5 is deposited on a nonconductive substrate between two electrodes by (a) contacting substrate and electrodes with gaseous P in the presence of water vapour and (b) applying an electric potential between the electrodes of sufficient strength to electrolyse the water vapour and form P2O5 only in the substrate region between the electrodes. The method is useful for depositing P2P5 for a moisture sensor or a fuel cell. Very thin continuos filsm can be formed, e.g. 0.5 mu thick, in the required region only, for very fast moisture cell response times, e.g. on humidity change from 1000 to 10 p.p.m., reading changes 90% in &lt;5s. A number of substrates can be automatically and simultaneously coated, and pore surfaces can be coated.
Active substances in fuel cells are regenerated by using photochem. reaction of Cr ions in the presence of chlorophyll. In the presence of chlorophyll, Cr3+ ions in aq. soln. are reduced according to photochem. reaction; 4 Cr3+ + 2H2O - 4Cr2+ + O2 + 4H+, and the fuel cell is based on the reverse reaction. In an example, an aq. soln. contg. 10 CrCl3 and 0.01% chlorophyll Cu-Na salt was filled into a well contg. an O electrode of Pt black and porous sintered Ni, a sintered Ni anode, and a acrylic container. The terminal voltage was 0.06 V, which increased to 0.40 V when the fuel cell was exposed to sunlight for 3 hr.
A fuel stack, comprises a number of cells electrically connected in series contg. an ionically conductive coolant fluid which removes heat from the stack and provides a path for shunt current from the positive to the negative end of the stack. The stack includes oxidisable material contacting the fluid at the positive end of the stack, a soluble salt of a metal is introduced into the coolant fluid, the metal of which goes into soln. as an ion at the positive end of the stack and the ion oxidises at an electrochemical potential below that at which the oxidisable stack material is oxidised for the level of shunt current through the fluid. Oxidn. of the metal ion prevents oxidn. and corrosion of the positive end of the stack.
A fuel cell using air as the oxidant is placed in an enclosure equipped with a high-capacity blower for removing the water vapour produced in the cell and to circulate it within the enclosure prior to discharge; and a means for feeding only the required amt. of air in the cell. Complete removal of water produced on the cathode is possible, and by using only the required amt. of air, the contamination of the electrolyte with CO2 present in air is minimised. In an example, a 100-W rated fuel cell using a 30% KOH electrolyte and a 2% H2N NH2 H2O fuel was placed in an enclosure equipped with a 300-l./min. blower for removing the gas produced in the cell and a 20-l./min. blower for removing the air from the enclosure and feeding the same amt. of air into the cell. On discharge for 6 months, a 100-ml. increase in the electrolyte vol. (85% evapn of the H2O produced) was obsd.    In contrast, a conventional cell with free passing of air showed a 50% increase in electrolyte vol. The K2CO3 formation rate was 40g/day, or 1/3 of that of a conventional cell. The cell voltage was higher and the discharge characteristics were superior to those of conventional cells.
H2NNH2 fuel cells are equipped with an automatic H2NNH2 control system which supplies H2NNH to the battery according to the H2NNH concn. detd. periodically by the concn.-detn. cell in the electrolyte loop. The periodical detn. of H2NNH concn. rather than continuous one prevents the increase of the voltage at the concn.-detn. cell owing to the electrode degrdn. and gives a more accurate control of H2NNH2 concn. In an example, a 100-watt H2NNH2-air type fuel cell was operated continuously by maintaining the H2NNH2 concn. at 2% by the automatic H2NNH2 conc.-detn. cell contg. Pt anode and Ni cathode, and operated periodically (5 sec. on, 55 sec. off) at 600 mA/cm3. The control system was designed so that the H2NNH2-supplying valve was opened when the voltage of the concn.-detn. cell was &gt;2 V.
A new propulsion system for submarines is based on a high-pressure gas reactor. A catalytic gas reactor serves for the reaction between fuel and H2O2 at high pressure. A diffusion cell separates H2 from the resulting products of reaction. A fuel cell feeds a steam generator for a turbine alternator. The waste gases of the reactor are passed to a propulsion turbine of the gas/water type which can be swivelled relative to the submarine. This power generating system is much smaller than that required by nuclear power systems. It does not require the extensive protective screens which are necessary for nuclear power reactors.
Catalytic structure comprises a substrate having a high surface area onto which has been adsorbed particles of colloidal platinum of particle size 15-25 angstroms, the particles of Pt having been obtd. from a colloidal soln. obtained by decomposition of a novel compsn. of formula (I): H3Pt(SO3)2(OH) in air and dispersion of it in water. (I) is prepd. by reacting chloroplatinic acid with Na2CO3 and NaHSO3, pptg. Na6Pt(SO3)4 from a practically neutral soln. from this reaction, adding a sulphonated copolymer of styrene and divinylbenzene, in the hydrogen form to replace the Na6, and concentrating the soln. The parent patent claimed prepn. of H3Pt(SO3)2(OH)2 and its use for prepg. catalytic structures. In the parent patent the formula had not been accurately established. This addn. establishes this formula and that of the 'white ppte.' of the parent patent which is Na6Pt(SO3)4.
In a fuel cell having an anode and cathode of graphite-plastic conductive substrates coated with active C particles and anolyte and catholyte compartments interconnected by an ion-exchange medium, the anolyte comprises a liq. source of monosulphide ions in a concn. &gt;1N (pref. 2-5N alkali-metal sulphide) during part of the electrochemical cycling and a catholyte comprising a liq. oxidising agent is operated by (a) flowing anolyte through the anolyte compartment at a rate and concn. that maintains S ions in excess of polarisation-preventing concn. to dissolve free S formed by electrochemical action of the cell, and (b) flowing catholyte through the catholyte compartment to produce a drain rate &gt;0.5A/in.2 and about 1.0V. The cell can provide the nominal 100 W-hr/lb. (including parasitic components) required for an electric vehicle, using safe, inexpensive materials.
The basic electrolyte of a full cell of the type comprising two parts, the power part and the decarbonatation part, the power part comprising an anode and a cathode separated by a membrane defining the anode and cathode chambers and the decarbonatation part comprising a similar arrangement, the cathodes being supplied with oxygen rich gas and the anode compartment of the power section with carbonaceous fuel, the anode compartment of the decarbonatation part with basic carbonate electrolyte issuing from the anode compartment of the power section, is decarbonised by injecting into the electrolyte at least one component forming formate ions on contact with the electrolyte, the amt. of the component thus supplied being such that the sum of the amt. of formate ions resulting from this cpd. and formed by oxidation of the fuel in the anode compartment of the power section ensure complete decarbonation of the electrolyte as well as a max value of the ratio of active surfaces S1 and S2 of the power and decarbonatation parts of the cell.
In a generator for supplying hydrogen to a fuel cell, the glow is regulated by cyclically modulating a constant area injector value between fully open and fully closed positions in response to a first actuating signal controlling the time for which the valve is open during each cycle and a second actuating signal for maintaining the valve closed for a fixed time in each cycle, the first actuating signal being produced by a comparator supplied with a reference signal from an integrator and with a control signal dependent upon the power produced in the fuel cell. There is thus reduced cost and complexity by elimination of valve position feedback mechanism requirement.
An electrochemical battery in which the cells are connected in series electrically and for electrolyte circulation in such a way that when electrolyte flows through a particular cell it does not flow through the adjacent cell or cells. Used for accumulators and fuel cells. Leakage currents and power loss are overcome.
In an H2-O2 fuel cell, the decompsn. of a metal hydride to produce H2 is controlled by the H2 pressure. The aq. alkaline electrolyte is brought into contact with a metal hydride such as calcium hydride, in an H2 generator and is then returned into the electrolyte space of the fuel cell. This makes the H2 prodn. independent of the temp. of the fuel cell. An external source of heat is not reqd. and the result is a very compact design. The design also provides for the discharge of the water of reaction and of the CO2.
Chrysotile asbestos is converted to a product contg. 80-90 wt. % Mg(OH)2 by heating a mixture of asbestos and a 20-60% aqn. sol. of KOH at 150-200 degrees C for 2-100 hrs. removing the KOH, washing the residue and repeating the cycle for a sufficient number of times to produce the required material. Used as fuel cell matrix for hydrogen oxygen fuel cells. The treated asbestos has excellent resistance to KOH at temp. &gt;100 degrees C while retaining the morphological props.
An asbestos matrix is made by vacuum stirring and deaerating a slurry of shredded asbestos in water or low boiling liq. hydrocarbon and vacuum filtering through a filter paper or a porous plaque. The asbestos matrix with a porosity of 70% is stripped from the filter and vacuum dried. The asbestos matrix is for fuel cells and electrolytic cells. The matrix has a greater porosity, higher bubble pressure and more uniform thickness than conventionally produced matrices and increases the performance and extends the life of the cells.
Fuel cell element, for the reaction of N2H4 in the electrolyte and gaseous O2, has an O2 electrode of catalytically active powder pressed onto one side of a skeleton, whilst the other side of the skeleton is provided with a gauze electrode contg. catalyst, past which the N2H4 in the electrolyte flow, as fuel electrode, the catalyst in the gauze electrode being unevenly distributed and having the highest concn. in the side towards the skeleton. The electrolyte pref. has a N2H4 concn. of up to 15 wt. % and is 2-8 M in KOH, whilst the O2 electrode consists of Ag-activated C and the fuel electrode of platinised Ni gauze. N2H4 decompsn. can be kept low and mixing potential formation at the O2 electrode suppressed without costly precautions.
In a fuel-cell power plant, a steam reform reactor comprises a burner with an airplenum and direct air inlet, and a plurality of chambers, one of which contains steam reform reaction catalyst and is surrounded in heat exchange relationship by a first duct, a second chamber containing the burner and providing a hot gas flow into the first duct, a second duct surrounding the first duc in heat exchange relationship and having an air inlet for receiving burner air and an air outlet opening into the burner air plenum, a shift conversion diameter surrounding the second duct and reform reactor in heat exchange relationship and having an inlet receiving the product of the reform reactor and an outlet for supplying processed hydrocarbon fuel to the fuel cell, and the ambient burner air source including a valve for supplying burner air to the inlet of the second duct during normal running and directly to the burner air plenum during start-up. Used for prodn. of commercial and domestic electricity. Plant has reduced size, weight and cost. More efficient electricity generation by improved heat exchange efficiency.
A stackable LiCl fuel cell comprises (a) a cylindrical housing contg. a number of spaced boundary walls, (b) a cylindrical porous graphite cathode contacting one boundary wall, (c) a cylindrical anode contacting another boundary wall, comprising a low density matrix of molten-Li-wettable metal fibres contg. a charge of metallic Li, these boundary walls contacting the anode and cathode of adjacent cells, (d) an insulating ring separating the anode and cathode to form a chamber suitable for contg. molten LiCl electrolyte, ne) an inlet for admitting gaseous Cl2 into the cathode and (f) a vent for removing LiCl reaction prods. formed by the cell reaction. The cell is capable of delivering a high energy output within 90s of activation and has a very high output/unit wt./unit time.
CO2 cru bber for a fuel cell reactant gas stream reducing CO2 concn. to &lt;0.25 ppm. comprises a packed bed of alkali hydroxide particles is not &gt;10 mu size and inert hydrophobic particles of a similar size. The latter are uniformly distributed and keep the alkali particles separated; the concn. of hydrophohic particles is 10-60 vol % of bed. Pref. material is PTFE. Device has low sensitivity to water vapour in the reactant gas stream.
Bonding onto the surface of plastic material (I) which is chemically or thermally cross-linkable by (A) applying a coating of an adhesive compsn. incorporating 1 other resin material (II), a crosslinking agent (III) and a catalyst (IV) dispersed in a solvent (V); (B) applying a cover tape or film at least partly made of (II); (C) evapg. most of the solvent at ambient temp.; (D) evapg. residual solvent at a higher temp.; (E) curing (II) at a higher temp which is &lt; b.pt. of (III); and (F) curing (I) at a still higher temp. Esp. for making bags or sealing covers made of PVA based resins, e.g. sheaths for fuel cell electrodes. Bonded seal had good strength and chemical resistance, esp. w.r.t. conc. alkali.
A heart pacemaker consists of a stimulating electrode and a counter electrode, with a pulse generator and an implantable glucose)oxygen biofuel cell. The glucose electrode is designed with a greater area than the stimulating electrode and acts as the counter electrode; the stimulating electrode is conductively connected to the glucose electrode and therefore has the same potential. High potentials of the stimulating electrode may lead to blood coagulation and also to irreversible damage to tissue close to the electrode. This is obviated by the lowering of the stimulation threshold to under 0.5 V.
Electrolysis cell system for producing oxygen and hydrogen includes an electrolysis cell with a pair of gas diffusion electrodes and an aqueous electrolyte matrix between the electrodes. Gas spaces are formed on the nonelectrolyte side of each electrode and one of the spaces has an inlet and outlet. The cell has a thermal exchange portion. A portion of one of the product gases (in this case hydrogen) is circulated through the outlet, the thermal exchange portion, and back through the inlet to the gas space. Water from a pressurised water supply is introduced into the recirculating product gas to maintain the temp. of the gas leaving the thermal exchange portion exit at a predetermined temp. A condenser removes heat from the recirculated gas stream leaving the thermal exchange portion and for condensing vaporised water entrained within the recirculating gas. A desired partial pressure of water vapour is established in the recirculating gas re-entering the gas space inlet. The cell is compact and relatively simple. The cell is fed with water and cooled by a single recirculating fluid stream. The circulation requirement for cooling fluid is minimised thus reducing the size of the pumps required. Water supplied to replenish the cell and heat removal are accomplished with a single recirculating product gas loop and one pump.
Rough surfaced or porous electrode attached to a matrix for acid electrolyte electrochemical cells, esp. fuel cells has a matrix separating the two electrodes which by expansion, undergoes an increase in volume and onto which the electrolyte is adsorbed chemically or physically, the surface of the matrix adapting itself to the shape of the electrode. Prevents loss of electrolyte acid and water over long periods and allows the tolerances on some of the parts of the battery to be somewhat relaxed. Diffusion of ions between the electrodes is improved, and the electrodes can be much thinner than in prior art so that diffusion of ions is easier.
Supply of gas under reduced pressure from regulator to user's apparatus in particular fuel cell is through diffusor (8). Gas from user's apparatus to ejector enters through connecting pipe (13). When spring-loaded valve (3) is open, high pressure gas enters through connecting pipe (4) into high pressure chamber (5), formed by two additional bellows (6), connected to moving cup (12), and flows through supersonic shape nozzle (7) into chamber (11), connected by ducts (9) to control chamber (10). As gas continues flowing through (7), its pressure in (11) and (10) increases, compressing spring-loaded vacuum bellows (1), secured to (12), and causing (12) to follow (1) motion. Stem (2) of (3) is constantly pressed against spherical end of (12) by (3) spring and in following (12) motion draws (3) after it and shuts it, cutting of high pressure gas supply and gas flow. As gas is used up in user's apparatus, its pressure drops, causing corresponding drop in gas pressure in (10) and (11). Bellows (1) is extended by spring and spherical end of (12) presses on (2) and (3), causing (3) to open and gas to enter through (4) into (5), again, gas flowing through (7) into (8) at supersonic speed creates rarification of gas stream under action of which gas is sucked in from (11) into (8), thereby ensuring a definite pressure drop between (11) and working chamber of apparatus. This results in circulation of gas between apparatus and ejector.
A fuel compsn. of a dimensionally stable sintered porous mass capable of generating hydrogen by sequential contact with an aq. hydroxide soln. consists of (a) silicon-contg. metal particles (I), (b) 5-50 wt% of a salt cpd. (II) admixed with and bonded to (I), (c) a silicate cement disposed on at least a portion of (I), the silicate cement being formed when the compsn. is wetted with the hydroxide soln. such that the amt. of (II) is sufficient to allow the silicate cement formed to dissolve at a greater rate, upon subsequent rewettings with the hydroxide soln., than if (II) had not been present. Compsn. is useful for generation of H2 for supply to a fuel cell. The formation of cement-like matl. on the surface of the particles, which reduces the rate of the reaction, is retarded. The fuel may be employed in a Kipp generator in reaction with hydroxide soln. to prod. H2 gas. The solid fuel compsn. may be shaped into rods and wafers which may be added to the generator to control H2 prodn.
A fuel cell has a pair of oppositely situated electrodes with an electrolyte matrix between them, at least one electrode having a continuous hydrophobic surface and with an electrolyte store behind one of the electrodes. The electrolyte store is a storage matrix contg. an aq. electrolyte similar to the electrolyte matrix with which it is connected via selected non-hydrophobic points, distributed uniformly over the whole hydrophobic surface of the electrode and having an insignificant expansion relative to the hydrophobic surface. This construction enables a matrix fuel cell to be produced with an electrolyte container connected to the electrolyte matrix, without bulky or costly components, e.g. special separator plates.
In a fuel cell involving catalytic anodes and cathodes sepd. by membranes into cells swept by aqs. electrolyte streams mixed with a gaseous fuel and an oxidising gas resp. the cells are extended vertically to provide overhead chambers for condensing and refluxing vapours (water) entrained in the gaseous stream(s) (fuel, air). The cells also incorporate reagents for decomposing any carbonates generated in situ into CO2. Used esp. for cells involving carbon based electrodes and swept by atmospheric air, using methanol, antural gas (methane) or hydrazine fuels. The cells may be enclosed in a plastic casing. Reduces water (or methanol) losses to allow cells to operate at higher temps. for increased power outputs. Cell life increased by suppression of carbonate build-up.
A hydrogen-oxygen type fuel cell contains electrolyte comprising 40-60% KOH, and an asbestos fibre matrix. Potassium silicate is added to the electrolyte to protect the asbestos from corrosion by the KOH; the wt. ratio K silicate to KOH being 0.05 0.15:1, and increase the operating life of the cell.
NH4+ in water is electrolysed continuously in the anodic chamber (I) to decompose it to N and H2O, and h obtained in the cathodic chamber (II) is used for generation of electricity in a fuel cell. In an example, when 3% aq. NH+4 in (I) and 20% NaOH in (II), both contg. activated C, with anion exchange diaphragm, were electrolysed, 100% NH3 was decomposed with 90% current efficiency.
A fuel cell comprises an anode (a fuel electrolyte), a cathode (an oxidizing electrode), an electrolyte container which is placed between the anode and the cathode and which has an exhaust pipe at the upside of the container, a gas chamber formed at the back of the cathode, a porous layer formed at the back of the anode having resistance to ion conduction and an electrolyte containing fuel filling a battery jar, the electrolyte is diffused in the electrolyte container through a porous layer and the anodic fuel electrode.
A fuel cell comprises an anode (a fuel electrode); a cathode (an oxidizing electrode); a space, between the anode and cathode, which contains a liq. mixt. of electrolyte and fuel, e.g. hydrazine, and which has a gas exhaust pipe; a space at the back of the anode contg. the liqs. and having liquid passage holes; a gas chamber at the back of the cathode; and an electrolyte contg. hydrazine in a battery jar. The liq. passage holes are passed outside through pipes to fully diffuse the electrolyte.
Solid state electrolyte for a fuel cell, has a first solid state electrolyte of CeO2, Gd2O3 and MgO or Ceo2, Sm2O3 and MgO, with a thin film of a ZrO2-Y2O3 layer or ThO2-Y2O3 layer.
Vanadyl phthalocyanine is prepd by reaction of anhydrous VCl3 with phthalodinitrile inboiling quinoline. Used as switching dyes in solid lasers, catalyst in fuel cells and oxidn reactions.    Cheap raw materials are used and a pure prod. obtd by a simple process without extensive purificn processes.
In a fuel cell comprising a stacked array of unit cells, subdivided into cell groups, further subdivided into blocks B, further subdivided into sub-blocks SB1, SB2, the unit cells are supplied with anolyte and catholyte feed and return systems by having each sub-block formed at one end with a plate having four grooves, at the other end with a plate having two pairs of holes therein respectively lined up with the ends of respective ones of the grooves and the unit cells in-between the end plates having eight passages for feeding in the anolyte and the catholyte, for returning the spent anolyte and the catholyte, and for coupling up the four lined up pairs of end plate holes and ends of end plate grooves. The inter cell I2R losses are minimised and the flow of anolyte and catholyte is uniform to all cell units. The modular construction and moulded parts lends to easy design change.
Fuel cells with alkali metal chlorite anolyte and alkali metal sulphide catholyte are equipped with pumps for circulating the electrolytes. The latter improves the cell efficiency, and allows to incorporate additional systems, such as purification, and replenishing apps. for the electrolyte. In an example, a cell consisting of a 200-cm.3 anodic chamber, a 200-cm.3 cathodic chamber, a diaphragm, a Ni cathode (50 cm.2), and a C anode coated with Pd black, was constructed with a 2 NaClO2 and 0.5-m NaOH anolyte and a 2 Na2S and 0.5 M NaOH catholyte circulating resp. through the anodic and cathodic chambers to give a very efficient fuel cell at 60-70 degrees.
The fuel cell has fuel chamber frames, electrode frames and air chamber frames fastened together with metal bolts coated with a PTFE layer.
Feeding of a reactant to a fuel cell is controlled by a valve whose operation is controlled in accordance with the concentration of reactant in the cell as determined by a sensor to which current pulses of 0.1 sec. duration, spaced by at least 4 sec., are supplied from a current source, the fuel cell terminals being selectively isolated at least for DC from the fuel feed control and the sensor. Current leakage between the fuel cell and the sensing and control elements is prevented.
A solid electrolyte for a fuel cell actuating at a high temp. is prepd. by irradiating with Li6 or B10 MgO-Al2O3 matl. to form a ternary solid soln. of MgO.Al2O3.Li2O.
The fuel can comprises a liq. chamber disposed between an oxidising electrode (air electrode) and a fuel electrode, an electrode for detecting fuel concn. is inserted into the liq. chamber and electrolyte is introduced into the chamber through the fuel electrode.
The device comprises a fuel cell; an anolyte tank contg. an electrolyte and a liq. fuel, such as hydrazine or ammonia which are pumped to the fuel cell; and a fuel storage cell. Gases such as N2 or CO2 generated in the fuel cell; are sepd. from the anolyte and sent to the fuel storage cell to prevent the oxidn. of the fuel.
Ca(OH)2 and/or CaO is mixed with alkali metal hydroxide and water and the resulting mixt. is pelletised and dried to obtain an absorbent having improved adsorptive capacity for CO2. THe CO2 adsorbent is esp. useful for removing CO2 from air for fuel cell or air cell. In an example, 3.5 kg Ca(OH)2 and 500 LiOH were added to 1.1l. water and the resulting mixt. was pelletised and dried in N stream at 105 degrees for 20 hr. to obtain powdery, porous absorbent (sp. surface 37 m2/g. The av. Co2 absorptivity of the absorbent was 82%, compared to 53 for the conventional one.
Electrolyte for fuel battery, consists of borophosphoric acid (1) and orthophosphoric acid (2) in a molar ratio (1):(2) of 1:6-1:1.    The electrolyte provides for a longer working life of porous carbon fuel battery electrodes.
A fuel cell consists of an anode chamber and a cathode chamber, sepd. by a reaction chamber with membrane partitions. The reagents are dissolved in the anode and cathode chamber by a suitable solvent and diffuse through the membranes into the reaction chamber. The prods. of reaction are continuously removed. The reactions take place at low temp and low pressure. Losses and maintenance are reduced to a min. The raw matls. used are easily obtainable. The reaction can be accelerated by higher temp. and pressure.
Prepn. of the title prods. useful in the mfr. of solid electrolytes and fuel ements, is simplified and the process temp. reduced, by incorporating ZrO2 in the material, in amts. of 35-40 moles %. In an example, a mixt. contg. (in moles %) HfO2 60, ZrO2 40 was combined with 15.8 wt.% of Y2O3, wetted with polyvinyl alcohol, ground in an agate mortar pressed into tablets using 2000 kg/cm2 pressure, dried at 150 degrees C and fired in the furnace of a high temp. X-ray chamber. The X-ray monitoring showed that a stabilised cubic solid soln. of fluorite type was completely formed when the temp. reached 1500 degrees C.
The device is located between two electrodes of an electrochemical system and comprises two central parts made in the form of a closed-end bellows either side of a peripheral part, which is usually made of insulating material. The two central parts, made from electrically conducting material, are forced against the electrodes by circulating a non-conducting fluid, also acting as a coolant, at a pressure of 2-10 bars inside the space bounded by the bellows. 1 current collecting plate is attached to the inside surfaces of the bellows with a conductor carrying the curent outside the system. A system can contain any number of the devices located between two electrodes.    The system can be used in any electrochemical system in which the various components require pressure to bind them together, e.g. electrolysers, electrodialisers and especially fuel batteries of the filter-press type. The system ensures good contact between electrode elements increasing the efficiency of the electrochemical generator and the amount of current collected, whilst combining the function of a cooling channel.
In a fuel cell system, in which aq. electroylte is circulated around a closed circuit, the rate of evaporation of water from the system is regulated to equla the rate of prodn. by monitoring the quantity of electrolyte in the system and controlling the temp. to maintain the quantity between limits. Permits maintenance-free operation with uniform available output under variable operating conditions.
The reaction water is septd. from fuel cells operated with hydrogen as the fuel and oxygen as the oxidising agent by circulating the electrolyte, heated by the heat loss, through an electrolyte cooler. It is brought into contact with one of the pressurized reactant gases which absorbs the water from the electrolyte in vapour form and is passed through a water separator before entering the fuel cell. A concentrator is inserted in the flowline before the electrolyte cooler. This ensures the contact between electrolyte and reactant gas which is necessary for the absorption of water in vapour form. The compressor output required is greatly reduced because the concentrator helps to reduce the pressure loss. The water absorption contact takes place at higher temp. and greater surface area; the electrolyte is not atomised and more, resulting in greater water purity.
In a fuel cell, an electrolyte-satd. matrix is provided between two electrodes, on coextensive therewith and the other shorter, so that part of the end of the matrix surface directly contacts one of the gas separators of the cell, whereby the electrolyte forms a wet seal preventing escape of gas. Suitable for use in many different types of cell to prevent mixing of the reactant gases.