| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte and a lithium ion secondary battery which enable the achievement of superior cycle characteristics by suppressing the generation of gas or the decomposition of an electrolyte even with a higher positive electrode potential in comparison to conventional ones.SOLUTION: A lithium ion secondary battery comprises a nonaqueous electrolyte which includes: a cyclic phosphoric ester compound (A) expressed by the general formula (1) below; a lithium salt compound (B) having no oxalic structure; a lithium salt compound (C) having an oxalic structure; and a nonaqueous solvent. (In the formula, Ris a group selected from a hydroxy group, an alkoxy group with 1-15C which may be substituted, an alkyl group with 1-15C which may be substituted, an alkenyl group with 2C-15C which may be substituted, an alkynyl group with 2-15C which may be substituted, and an aryl group with 6-15C which may be substituted, and Ris an alkylene group with 1-10C which may be substituted). |
