TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrolytic salt lithium hexafluorophosphate, lithium difluorophosphate, lithium monofluorophosphate, lithium tetrafluoroborate, lithium-containing compound (LiN(SO2CF3)2), lithium-containing compound (LiN(SO2C2F5)2), fluorine-containing compound (LiN(SO2F)2), difluoro bis(oxalate-O,O')lithium phosphate and tetrafluoro(oxalate-O,O')lithium phosphate. The positive electrode active material is chosen from lithium complex oxide and lithium-containing olivine-type phosphate. The carbon material with negative electrode active material is capable of occluding and discharging lithium metal, lithium alloy and lithium.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The content of organophosphorus compound (I) is 0.001-10 %mass with respect to total content of nonaqueous electrolyte. The organophosphorus compound (I) is 2-propynyl 2-(diethyl phosphoryl) acetate, 2-propynyl 2-(ethoxy(ethyl)phosphoryl)acetate, 2-propynyl 2-(dimethoxy phosphoryl)acetate, 2-propynyl 2-(diethoxy phosphoryl)acetate, 2-propynyl 2-(diphenoxy phosphoryl)acetate, 2-propynyl 2-(diethoxy phosphoryl)-2-fluoro acetate, 2-propynyl 3-(diethoxy phosphoryl)propanoate, 1-methyl-2- propynyl 2-(diethoxy phosphoryl)acetate, 1,1-dimethyl-2-propynyl 2-(diethoxy phosphoryl)acetate, 2-methoxyethyl 2-(diethoxy phosphoryl)acetate, 2-trifluoromethylphenyl 2-(diethoxy phosphoryl)acetate, 4-trifluoromethylphenyl 2-(diethoxy phosphoryl)acetate, methyl-2-(2-oxide-1,3,2-dioxa phosphoran-2-yl)acetate, 2-(2-(diethoxy phosphoryl)acetoxy)ethylmethyl oxalate, methyl-2-(2-(diethoxy phosphoryl)acetoxy)propanoate, methyl(diethoxy phosphoryl)acetate, dimethyl(diethoxy phosphoryl)oxalate, ethane-1,2-diylbis(2-(diethoxy phosphoryl)acetate), 2-butyne-1,4-diylbis(2-(diethoxy phosphoryl)acetate), bis(dimethoxy phosphoryl)(methyl)oxalate, bis(diethoxy phosphoryl)(methyl)oxalate, and 2-cyanoethyl 2-(diethoxy phosphoryl)acetate. The nonaqueous solvent contains cyclic carbonate and chain-shaped ester. The nonaqueous electrolyte contains cyclic carbonate, ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 4-fluoro-1,3-dioxolan-2-one, transformer,cis-4,5-difluoro-1,3-dioxolan-2-one, vinylene carbonate, and vinyl ethylene carbonate. The chain-shaped ester is chain-shaped ester having methyl. The non-aqueous electrolyte further contains nitrile, cyclic form or chain-shaped sulfonyl group-containing compound, and triple bond containing compound. The nitrile is succinonitrile, glutaronitrile, adiponitrile, and pimelonitrile. The sulfonyl group-containing compound contains 1,3-propane sultone, 1,3- butane sultone, 1,4-butane sultone, 2,4-butane sultone, ethylene sulfite, and 4-(methylsulfonyl methyl)-1,3,2-dioxa thiolane-2-oxide. The triple bond-containing compound is 2-propynyl methyl carbonate, methanesulfonic acid 2-propynyl, di(2-propynyl)oxalate, and 2-butyne-1,4-diyl dimethane sulfonate.