TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The lithium salt is selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4 LiCF3SO3, Li(CF3SO2)2N, LiC4F9SO3, LiSbF6, LiAlO4, LiAlCl4, LiN(CxF2x+1SO2)(CyF2y+1SO2), LiCl, and/or LiI.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The cyclic carbonates and chain carbonates are mixed in a volume ratio of 1:1-1:9.The organic solvent is a mixed solvent of a carbonate-based solvent and an aromatic hydrocarbon solvent mixed in a volume ratio of 1:1-10:1The aromatic hydrocarbon solvent is selected from benzene, fluorobenzene, toluene, trifluorotoluene, and/or xylene.The non-aqueous electrolyte further comprises 0.5 to 10 weight% of an acrylate-based polymer and 0.1 to 5 weight% of acetonitrile, and an aprotic solvent selected from benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, gamma-butyrolactone, dioxolane, 4-methyldioxolane, N,N-dimethylformide, dimethylacetamide, dimethylsulfoxide, dioxane, 1,2-dimethoxyethane, sulforane, dichloroethane, diethyleneglycol and/or dimethylether.Preferred Process: The lithium secondary battery is heat-treated, and charged to form an organic solid electrolyte interface film. In the case where lithium metal is used for cathode, the battery is charged at a constant current until the battery reaches 0.8-1.3 V of cathode voltage, and further charged for 0.1-8 hours at a constant voltage.The battery is additionally charged to 0-0.1 V at a constant current, and is then charged for 1-8 hours at a constant voltage. Alternately, a polymer electrolyte is interposed between anode and cathode to fabricate a lithium secondary battery.The lithium secondary battery is heat-treated, and charged to form an organic solid electrolyte interface film. In the case where lithium composite metallic oxide is used for anode, the battery is charged at a constant current until the battery reaches 2.5-3.1 V, and further charged for 0.1-8 hours at a constant voltage.The battery is additionally charged to 4-4.3 V at a constant current, and is then charged for 1-8 hours at a constant voltage.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The acrylate-based polymer is selected from polyethyleneglycoldimethacrylate and/or polyethyleneglycoldiacrylate. SPECIFIC COMPOUNDS - The organic solvent is selected from cyclic carbonates, such as ethylene carbonate, propylene carbonate and/or butylene carbonate, and/or chain carbonates, such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate and/or methylethyl carbonate.    The compound additive of formula (I) is selected from (meth)acrylonitrile, pentenenitrile, 2-methylpentenenitrile and/or 2-ethylpentenenitrile.    EXAMPLE - A non-aqueous organic solution was prepared by mixing ethylene carbonate and dimethyl carbonate, in a volume ratio of 1:1. To this solution 1 M lithium hexafluorophosphate and 1 wt.% of acrylonitrile, were added with respect to the total weight of the non-aqueous organic solution. An electrolyte was obtained. The electrolyte was then used for preparing a lithium ion battery cell. The thickness variation after charging lithium ion battery cell, was 6.5%. The thickness variation after storing the battery at 85 degreesC, was 11.9%, 17.7%, 20.2% and 30.3%, after 4, 24, 48 and 96 hours, respectively. The lithium ion battery cell showed a decomposition voltage of 0.95 V, and had excellent cycle life characteristics.