TECHNOLOGY FOCUS - POLYMERS - Preferred Preparation: The polymer electrolyte is prepared by dissolving a polymer or polymer mixture in a mixture of a plasticizer and an organic electrolyte solution, filling the polymeric solution into a barrel of an electrospinning apparatus, and discharging the polymeric solution using a nozzle. Preferred Component: The plasticizer is propylene carbonate, butylene carbonate, 1,4-butyrolactone, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxyethane, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide, ethylene carbonate, ethylmethyl carbonate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, polyethylene sulforane, tetraethylene glycol dimethyl ether, acetone, and/or alcohol. The polymer is polyethylene, polypropylene, cellulose, cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, polyvinylpyrrolidonevinylacetate, poly(bis(2-(2-methoxyethoxyethoxy))phosphagene), polyethyleneimide, polyethyleneoxide, polyethylenesuccinate, polyethylenesulfide, poly(oxymethylene-oligo-oxyethylene), polypropyleneoxide, polyvinyl acetate, polyacrylonitrile, poly(acrylonitrile-co-methylacrylate), polymethylmethacrylate, poly(methylmethacrylate-co-ethylacrylate), polyvinylchloride, poly(vinylidenechloride-co-acrylonitrile), polyvinylidenedifluoride, and/or poly(vinylidenefluoride-co-hexafluoropropylene).The polymer electrolyte also includes not more than 20 wt.% filling agent that can be a polytetrafluoroethylene.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The organic solvent is ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and/or ethylmethyl carbonate. It also comprises methyl acetate, methyl propionate, ethyl acetate, ethyl propionate, butylenecarbonate, gamma-butylactone, 1,2-dimethoxyethane, dimethylacetamide, and/or tetrahydrofuran to improve a low-temperature characteristic.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The lithium salt is lithium phosphorus hexafluoride (LiPF6), lithium perchlorate, lithium arsenic hexafluoride (LiAsF6), lithium borofluoride (LiBF4), or LiCF3SO3. The filling agent is titanium dioxide, barium titanate, lithium oxide, lithium fluoride, lithium hydroxide, lithium nitride, barium oxide, sodium oxide, magnesium oxide, lithium carbonate, lithium aluminate, silicon dioxide, and/or aluminum dioxide. EXAMPLE - To a mixture of 1M LiPF6 solution (100 g) in EC-DMC and propylene carbonate (10 g) as a plasticizer, polyvinylidenefluoride (20 g) was added. The mixture was stirred at 80degreesC for 2 hours to give a clear polymeric solution. The solution was filled into barrel of an electrospinning apparatus and discharged into a metal plate to prepare a polymer electrolyte with a thickness of 50 microns. The electrolyte was inserted between a graphite anode and lithium cobaltite cathode, and the plates were cut and laminated. Terminals were welded on to the electrodes and the laminated plate was inserted into a vacuum casing.    A 1M LiPF6 solution in EC-DMC was injected into the casing and vacuum-sealed to fabricate a lithium secondary battery. The battery showed an improved electrode capacities and cycle life from a decrease in interface resistance and an increase in ionic conductivity due to good adherence of the electrodes and separator film.