Patent ID: 7700232

Claim:
A non-aqueous electrolytic solution for a lithium secondary battery which comprises an electrolyte salt in a non-aqueous solvent, which contains a tert-alkylbenzene compound in an amount of 0.1 to 10 wt. % based on an amount of the solution and which further contains a benzene compound having a benzene ring substituted with a hydrocarbon group having 1 to 4 carbon atoms via at least one tertiary carbon atom, in an amount of 0.5 wt. % or less and more than 0.001 wt. % based on the amount of the tert-alkylbenzene compound, wherein the tert-alkylbenzene compound is at least one of tert-butylbenzene, tert-pentylbenzene, 1,4-di-tert-butylbenzene, 4-fluoro-tert-butylbenzene, 4-tert-butylbiphenyl, 1,3-di-tert-pentylbenzene, 1,4-di-tert-pentylbenzene, or 1-tert-butyl-4-tert-pentylbenzene, and wherein the benzene compound having a benzene ring substituted with a hydrocarbon group having 1 to 4 carbon atoms via at least one tertiary carbon atom is at least one of sec-butylbenzene, isopropylbenzene, 1,2-dimethylpropylbenzene, 1,2-dimethylindan, 1,3-dimethylindan, 1-methyltetrahydronaphthalene, 1-tert-butyl-3-isopropylbenzene, 1-tert-butyl-4-isopropylbenzene, 4-fluoro-isopropylbenzene, 4-fluoro-sec-butylbenzene, 4-sec-butylbiphenyl, 1-tert-pentyl-3-isoprolpylbenzene, or 1-tert-pentpyl-4-isopropylbenzene.