TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The active material of positive electrode is a composite metal oxide containing lithium, and cobalt, manganese and/or nickel, or lithium-containing olivine-type phosphate containing iron, cobalt, nickel and/or manganese. The active material of negative electrode is chosen from carbon material, tin, tin compound, silicon, silicon compound, and lithium-titanate compound, capable of occluding and discharging lithium metal, lithium alloy, or lithium.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The content of compound (I) in the nonaqueous electrolyte is 0.01-5 %mass. The nonaqueous solvent contains a cyclic carbonate and a linear carbonate. The linear carbonate contains both symmetrical linear carbonate and asymmetrical linear carbonate. The cyclic carbonate contains 1 or more chosen from ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, and cyclic carbonate containing fluorine atom or unsaturated bond. The cyclic carbonate containing fluorine atom contains 1 or more chosen from 4-fluoro-1,3-dioxolan-2-one and trans or cis-4,5-difluoro-1,3-dioxolan-2-one. The cyclic carbonate containing unsaturated bond contains 1 or more chosen from vinylene carbonate, vinyl ethylene carbonate, and 4-ethynyl-1,3-dioxolan-2-one. Preferably, the cyclic carbonate contains ethylene carbonate, propylene carbonate, vinylene carbonate, or cyclic carbonate containing fluorine atom. The asymmetrical linear carbonate is 1 or more chosen from methyl ethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, methyl butyl carbonate, and ethyl propyl carbonate. The symmetrical linear carbonate is 1 or more chosen from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate. The electrolytic salt contains 1 or more types of lithium salt chosen from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfuryl)imide.