TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Cell: The cell (C1) further comprises a dissolved a solid, liquid or gaseous oxidant.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Electrolyte: In the composite solid electrolyte, the separator has a metal ion conductivity of 10-6 S/cm or 10-6 to 10-2 S/cm. The substantially impervious composite solid electrolyte is in the form of substantially impervious composite solid structure comprising an inorganic solid ion conducting layer having holes; and a component contained in the holes of the inorganic solid ion conducting layer and providing a fluid barrier, where the inorganic solid ion conducting layer has a metal ion conductivity of greater than 10-7 ohm-1cm-1. The component contained in the holes comprises a material selected from polymers, glasses, ceramics, glass ceramics and metals. The component contained in the holes is not conductive to metal ions. The component contained in the holes comprises a polymer. The component contained in the holes comprises an alkali metal ion conductive polymer. The component contained in the holes comprises a ceramic selected from Al2O3, zirconium compounds, colloidal silicas, and/or titanium oxides. The substantially impervious composite solid electrolyte, comprises: a base component comprising an inorganic solid electrolyte having holes; and a component contained in the base component holes and providing a fluid barrier, where the composite layer has a metal ion conductivity of greater than 10-7 ohm-1cm-1. Preferred Components: The conductive metal ion is an alkali metal ion (preferably Li). The base component has metal ion conductivity of 10-6 S/cm or 10-6 to 10-2 S/cm. The density of the base component is greater than 50% and less than 75% of the theoretical density of the base component material. The density of the base component is greater than 75% and less than 95% of the theoretical density of the base component material. The density of the base component is greater than 95% of the theoretical density of the base component material. The base component comprises a material selected from glassy or amorphous active metal ion conductors, ceramic active metal ion conductors, and glass-ceramic active metal ion conductors. The base component comprises a material selected from sodium and lithium beta-alumina, glass ceramic alkali metal ion conductors, Nasiglass, LISICON, NASICON, Li0.3La0.7TiO3 and silicate glasses. The base component comprises LISICON selected from lithium metal phosphates. The base component comprises (mol.%): P2O5 (26-55), SiO2 (0-15), GeO2+TiO2 (in which GeO2 (0-50) and TiO2 (0-50%)) (25-50), ZrO2 (0-10), M2O3 (0-10), Al2O3 (0-15), Ga2O3 (0-15), Li2O (3-25) and containing a predominant crystalline phase composed of Li1+x(M,Al,Ga)x(Ge1-yTiy)2-x(PO4)3 and/or Li1+x'+y'Q'x'Ti2-x'Siy'P3-y'O12. The base component material comprises Li1+x'1M'x'1Hf2-x'1(PO4)3. The base component material is a lithium lanthanum titanate. The lithium lanthanum titanate is Li3x'2La(2/3)-x'2TiO3. The filler component comprises a material selected from polymers, glasses, ceramics, glass ceramics and metals. The filler component is not conductive to metal ions. The filler component comprises a ceramic selected from Al2O3, ZrO2, SiO2, CeO2 and/or Al2TiO5. The supporting salt is selected from LiPF6, LiBF4, LiAsF6, LiClO4, LiSO3CF3, LiN(CF3SO2)2 and LiN(SO2C2F5)2 (preferably LiPF6, LiBF4, LiAsF6, LiClO4, LiSO3CF3, or LiN(CF3SO2)2). The active metal anode comprises an alkali metal (preferably Li). The anode comprises active metal intercalating material. The active metal intercalating material comprises carbon. The protective membrane architecture further comprises an active metal ion conducting separator layer comprising a non-aqueous anolyte, where the separator layer being chemically compatible with the active metal and in contact with the anode, and where the composite solid electrolyte is in contact with the separator layer. The separator layer comprises a semi-permeable membrane impregnated with a non-aqueous anolyte. The semi-permeable membrane is a micro-porous polymer. The anolyte is in the liquid phase. The anolyte is in the gel phase. The anolyte comprises a gelling agent; a plasticizer; and Li salt. The protective membrane architecture comprises a laminate, where the laminate comprises, a first material layer in contact with the anode, the first material being ionically conductive and chemically compatible with the active metal; and a second material layer in contact with the first material layer, where the second material layer comprises the composite solid electrolyte. The first material layer comprises a material selected from composite reaction product of active metal with Cu3N, active metal nitrides, active metal phosphides, active metal halides, active metal phosphorus sulfide glass and active metal phosphorus oxynitride glass. The first material layer comprises a material selected from composite reaction product of alkali metal with Cu3N, L3N, Li3P, LiI, LiF, LiBr, LiCl and lithium phosphorus oxynitride (LiPON). The first material layer comprises the composite reaction product of Li with Cu3N. The first material layer comprises LiPON. The cathode structure comprises an electronically conductive component, an ionically conductive component, and an electrochemically active component, where at least one cathode structure component comprises an aqueous constituent. The cathode structure comprises an aqueous electrochemically active component. The aqueous electrochemically active component is water or seawater. The aqueous electrochemically active component comprises water soluble oxidant selected from gaseous, liquid and/or solid oxidants. The water soluble gaseous oxidants are selected from O2, SO2 and NO2, and the water soluble solid oxidants are selected from NaNO2, KNO2, Na2SO3 and K2SO3. The water soluble oxidant is hydrogen peroxide. The ionically conductive component and the electrochemically active component are comprised of an aqueous electrolyte. The aqueous electrolyte is selected from strong acid solutions, weak acid solutions, basic solutions, neutral solutions, amphoteric solutions and/or peroxide solutions. The aqueous electrolyte comprises members selected from aqueous solutions of HCl, H2SO4, H3PO4 acetic acid/Li acetate, LiOH; sea water, LiCl, LiBr, LiI, NH4Cl, NH4Br and/or hydrogen peroxide (preferably seawater and hydrogen peroxide). The cathode structure electronically conductive component is a porous catalytic support. The cathode structure electrochemically active material comprises air. The ionically conductive material comprises an aqueous constituent. The ionically conductive material comprises a neutral or acidic aqueous electrolyte. The aqueous electrolyte comprises LiCl. The aqueous electrolyte comprises one of NH4Cl, and HCl. The cathode structure comprises an air diffusion membrane, a hydrophobic polymer layer, an oxygen reduction catalyst, an electrolyte, and an electronically conductive component/current collector. The cathode structure electrochemically active component comprises a metal hydride alloy. The cathode structure ionically conductive component comprises an aqueous electrolyte. The cathode structure comprises an aqueous ionically conductive component and a transition metal oxide electrochemically active component. The transition metal oxide is selected from NiOOH, AgO, iron oxide, lead oxide and manganese oxide. The ionically conductive component is a non-aqueous catholyte comprising at least one non-aqueous solvent and non-aqueous solvents comprise more than 50% of the catholyte solvent volume, and where the electrochemically active component is O2 obtained from ambient air. The ionically conductive component comprises a non-aqueous catholyte selected from organic liquids and ionic liquids. The catholyte is a solution of a Li salt in an aprotic solvent (S1), and the supporting salt. The liquid or gaseous oxidant in the cell (C1) selected from lithium polysulfides, NO2, SO2, and SOCl2 (preferably lithium polysulfides). The density of the inorganic solid electrolyte matrix is greater than 50% and less than 75% of the theoretical density of the inorganic solid electrolyte matrix material. The density of the inorganic solid electrolyte matrix is greater than 75% and less than 95% of the theoretical density of the inorganic solid electrolyte matrix material. The density of the inorganic solid electrolyte matrix is greater than 95% of the theoretical density of the inorganic solid electrolyte matrix material. The inorganic solid electrolyte matrix comprises a material selected from glassy or amorphous active metal ion conductors and ceramic active metal ion conductors. The inorganic solid electrolyte matrix comprises a material selected from lithium alumina, glass ceramic alkali metal ion conductors and silicate glasses. The density of the inorganic solid conducting layer is greater than 50% and less than 75% of the theoretical density of the inorganic solid conducting layer material. The density of the inorganic solid conducting layer is greater than 75% and less than 95% of the theoretical density of the inorganic solid conducting layer material. The density of the inorganic solid conducting layer is greater than 95% of the theoretical density of the inorganic solid conducting layer material. The inorganic solid conducting layer comprises a material selected from glassy or amorphous active metal ion conductors and ceramic active metal ion conductors. The inorganic solid ion conducting layer comprises a material selected from lithium alumina, glass ceramic alkali metal ion conductors and silicate glasses.x=0.8;y=0-0.1;M=Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm or Yb;x'=0-0.4;y'=0-0.6;Q'=Al or Ga;M'=Cr, In, Fe, Ta, Sc, Lu or Y;x'1=0-0.5;x'2=0-0.16.    TECHNOLOGY FOCUS - METALLURGY - Preferred Alloy: The metal hydride alloy comprises one of an AB5 and an AB2 alloy.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The anolyte comprises a solvent (S1) selected from organic carbonates, ethers, esters, formates, lactones, sulfones, sulfolane and/or 1,3-dioxolane (preferably EC, PC, DEC, DMC, EMC, THF, 2MeTHF, 1,2-DME or higher glymes, sufolane, methyl formate and/or methyl acetate). The plasticizer is selected from EC, PC, DEC, DMC, EMC, THF, 2MeTHF and/or 1,2-DME. The non-aqueous solvent is selected from aprotic solvents including N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), dimethylsulfoxide (DMSO), hexamethylphosphoramide (HMPA), and acetonitrile (AN). The non-aqueous solvents are a non-aqueous protic solvent selected from alcohols, diols and liquid polyols. The plasticizer is selected from carbonate, 1,2-dimethoxy ethane, tetrahydrofuran and/or 1,3-dioxolane.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The filler component comprises a polymer. The polymer is selected from polyisobutylene, epoxy, polyethylene, polypropylene and/or polytetrafluoroethylene (preferably epoxy, polyethylene and/or polypropylene). The filler component comprises an alkali metal ion conductive polymer. The alkali metal ion conductive polymer is selected from polyethylene oxide (PEO), cross-linked PEO and/or amorphous PEO. The gelling agent is selected from PVdF, PVdF-HFP copolymer, PAN, and/or PEO (preferably PAN and/or PEO). EXAMPLE - No suitable example given.