TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The non-aqueous solvent is a mixed solvent containing ethylene carbonate and propylene carbonate at a ratio 15:85-75:25. Preferred Electrolyte: The electrolyte contains as lithium salt e.g. lithium phosphofluoride (LiPF6), lithium borofluoride (LiBF4), LiN(CF3SO2)2 and/or LiN(C2F5SO2)2. The electrolytic solution contains 0.4-1 mol/kg of lithium salt and 0.2-2 wt.% of difluoroanisole.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The matrix polymer comprises one or more of polyvinylidene fluoride (PVDF), polyethylene oxide, polypropylene oxide, polyacrylonitrile and polymethacrylonitrile. Preferably, the polymer contains PVDF or a copolymer of PVDF with hexafluoropropylene at a copolymerization ratio not greater than 7.5%. EXAMPLE - A positive electrode was prepared by dispersing lithium cobaltate-polyvinyldiene fluoride (PVDF) slurry on both surfaces of an aluminum foil. A negative electrode was prepared by dispersing artificial graphite and PVDF powder (as slurry) on both sides of a copper foil. The sheets were cut into strips and attached to leads. A gel electrolyte layer was formed as follows. PVDF- containing hexafluoropropylene (HFP) copolymer (at copolymerization ratio of 6.9%), non-aqueous electrolytic solution and dimethyl carbonate were mixed and dissolved to obtain a sol polymer electrolytic solution. The non-aqueous electrolytic solution was prepared by dissolving 0.85 mol/kg of LiPF6 in a mixed solvent of ethylene carbonate (EC) and propylene carbonate (PC) at a ratio 15:85. 1 wt.% of 2,4-difluoroanisole (DFA) and 0.5 wt.% of vinylene carbonate (VC) were added. The electrolytic solution was uniformly applied to both surfaces of the electrodes and dried to form an electrolyte layer. The strip positive electrode with gel electrolyte layer and strip negative electrode with electrolyte layer were layered and rolled to obtain a rolled electrode body. The electrode body was sealed in a casing film to obtain a gel electrolyte cell. The cycle characteristic of the cell was 81%, initial charge/discharge efficiency was 81% and low temperature characteristic was 55%. The load characteristic of the cell was 98% and initial charge/discharge capacity was 605 mAh. The cell with electrolyte containing mixed solvent of EC and PC, with VC had improved charge/discharge efficiency, cell capacity. Cycle characteristics were found to be improved when PC was contained in a greater amount.