TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Properties: The anion of organic lithium salt has lowest unoccupied molecular orbital energy of -1 eV to 2.7 eV and highest occupied orbital energy of -4.5 eV to -3 eV. Preferred Composition: The content of organic lithium salt is 0.1-30 %mass with respect to total content of nonaqueous electrolyte solution. The content of acetonitrile in nonaqueous electrolyte solution is 70-100 vol.% with respect to total content of nonaqueous electrolyte solution. The nonaqueous electrolyte solution further contains inorganic lithium salt, ionic compound, non-nitrile-type additive, inorganic lithium salt, dinitrile compound and ionic compound comprising cation having nitrogen atom. The inorganic lithium salt is compound having fluorine atom, or compound having phosphorus atom, preferably lithium hexafluorophosphate. The content of inorganic lithium salt is 0.1-4 %mass with respect to total content of nonaqueous electrolyte solution. The non-nitrile-type additive is carbonate, preferably cyclic carbonate or compound having carbon-carbon double bond, or bivalent group-containing compound of formula: R1-A-R2 (I), more preferably ethylene sulfite, propylene sulfite, butylene sulfite, pentene sulfite, sulfolane, 3-methyl-sulfolane, 3-sulfolene, 1,3-propane sultone, 1,4-butane sultone, 1,3-propanediol sulfate and/or tetramethylene sulfoxide. The organic lithium salt is organic lithium salt having boron atom, or organic lithium salt having organic ligand, preferably lithium bis(oxalate)borate and/or lithium oxalate difluoroborate. The dinitrile compound is of formula: NC-(CR3R4)2a-CN. The cation having nitrogen atom is pyridinium cation. The anion of ionic compound is hexafluorophosphate. The positive electrode (120) of nonaqueous secondary battery contains active material which occludes and discharges lithium ion, preferably metal chalcogenide having metal oxide comprising lithium, and lithium. The negative electrode (130) of nonaqueous secondary battery contains active material which occludes and discharges lithium ion and metallic lithium, or contains metallic lithium, carbon material, and material containing lithium and element in which alloy formation is carried out.R1,R2=alkyl optionally substituted by halo or aryl, or aryl optionally substituted by halo or alkyl, preferably 1-4C alkyl optionally substituted by halo or phenyl, or phenyl optionally substituted by halo;or R1+R2+A=cyclic structure optionally having unsaturated bond;R3,R4=H or alkyl;a=1-6;andA=-O-S(=O)-O-, -S(=O)2-, -S(=O)2-O-, -O-S(=O)2-O- or group of formula (i).