NONAQUEOUS ELECTROLYTIC SOLUTION FOR SECONDARY BATTERIES, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide: an incombustible nonaqueous electrolytic solution for secondary batteries which allows a lithium ion secondary battery superior in cycle characteristics to be obtained; and a safe lithium ion secondary battery superior in cycle characteristics.SOLUTION: A nonaqueous electrolytic solution for secondary batteries comprises: an electrolyte; and a liquid composition. The electrolyte includes at least one lithium salt. The liquid composition includes: at least one fluorine-containing solvent (α) selected from a group consisting of a fluorine-containing ether compound, a fluorine-containing chain carboxylic ester compound and a fluorine-containing chain carbonate compound; a cyclic carboxylic ester compound; and an organic sulfur compound (other than the electrolyte). A lithium ion secondary battery comprises the nonaqueous electrolytic solution for secondary batteries.