TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Battery: The battery uses greater than or equal to2 capsules containing greater than or equal to2 materials contained in it for use together. The release rate of the release material is (1 - 10000) micrograms/day. The size of the controlled-release capsule is less than 5 microns. The battery further comprises material identical and/or similar to that contained in the controlled-release capsule, in addition to the controlled-release capsule.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The release material is a material necessary for formation and restoration of a solid electrolyte interface (SEI) layer, and is selected from vinylene carbonate (VC), vinylene ethylene carbonate, fluoro-ethylene carbonate, succinic anhydride, lactide, caprolactam, ethylene sulfite, propane sultone (PS), propene sultone, vinyl sulfone, their derivative and/or halogen-substituted compounds; an electrolyte additive that inhibits adverse side reactions occurring in the battery, and is at selected from ethylenediaminetetraacetic acid, tetramethylethylene diamine, pyridine, dipyridyl, ethylene bis(diphenylphosphine), butyronitrile, succinonitrile, iodine, ammonium halogenate and/or their derivatives; or a material that improves thermal stability of the battery, and is selected from hexamethyldisiloxane, hexamethoxycyclotriphosphazene, hexamethylphosphoramide, cyclohexylbenzene, biphenyl, dimethylpyrrole and/or their derivatives.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The cell of the controlled-release capsule is composed of an electrolyte-insoluble material, selected from polyethylene, polypropylene, polystyrene, nylon, polycaprolactone, polyethylene terephthalate, polyurethane, gelatin, chitosan, cellulose and/or their derivatives. Preferred Method: The controlled-release capsule is prepared by solvent evaporation, coacervation, interfacial polycondensation, in-situ polymerization, piezoelectric process, or spray drying. EXAMPLE - A controlled-release capsule was prepared as follows. Polystyrene (PS) was dissolved in dichloromethane (DCM) to obtain a dispersion (25 ml). An aqueous solution (250 ml) containing vinylene chloride (VC) (5 wt.%) and gelatin (5 wt.%) was prepared as a stabilizer. The dispersion was added to the aqueous solution to form an oil/water emulsion and DCM was evaporated to obtain a PS capsule containing VC which was washed with distilled water. A battery was prepared as follows. An anode was fabricated by adding carbon active material MCMB10-28 (RTM: carbon active material) (93 wt.%) and Kynar 761 (RTM: polyvinylidene difluoride (PVDF)) (7 wt.%) to N-methyl-2-pyrrolidone (NMP) as a solvent, mixing for 2 hours and coating the resulting mixture on a copper foil current collector, followed by drying at 130degreesC. A cathode was fabricated by adding LiCoO2 (91 wt.%), Kynar 761 (RTM: PVDF) (3 wt.%) and KS-6 (RTM: conductive carbon) (6 wt.%) to N-methyl-2-pyrrolidone (NMP) as a solvent, mixing the added materials for 2 hours and coating the mixture on an aluminum foil current collector, followed by drying at 130degreesC. Then, Celgard 2400 (RTM: separator) was interposed between the anode and cathode to obtain a pouch-type cell. A lithium secondary battery was fabricated by injecting a solution of 1M LiPF6 in ethylene carbonate/ethyl methyl carbonate (EC/EMC) as an electrolyte solution and VC (2 wt.%), and an electrolyte including a VC-containing, controlled-release capsule (5 wt.%), as additives. A comparative battery was fabricated similarly as the test battery, except that an electrolyte solution not containing controlled-release capsule was used. The batteries were then evaluated for lifespan characteristics by subjecting to 200 charge/discharge cycles at a current density of 0.5 C and 45degreesC. The percent retention of discharge capacity of the battery upon 100 and 200 repeated charge/discharge cycles was calculated relative to the percent retention of discharge capacity upon one charge/discharge cycle. The batteries were then evaluated for high temperature storage characteristics by subjecting to full charging, followed by storage at 60degreesC for 6 hours and increases in thicknesses of batteries were measured. The results for the test/comparative batteries were as follows: % discharge capacity upon 100 cycles versus 1 cycle = 91/93; % discharge capacity upon 200 cycles versus 1 cycle = 81/61; and thickness increase after 6 hours storage at 60degreesC = 0.53/0.48. The test batteries exhibited a high capacity retention rate as compared to comparative battery. The test battery also showed relatively small increase in thickness of battery.