NONAQUEOUS ELECTROLYTE SOLUTION AND LITHIUM SECONDARY BATTERY CONTAINING THE ELECTROLYTE SOLUTION

摘要

PURPOSE: A nonaqueous electrolyte solution and a lithium secondary battery containing the electrolyte solution are provided, to prevent the increase of the thickness of a battery during storage at a high temperature in or after charging and improving the lifetime and the stability of a battery. CONSTITUTION: The nonaqueous electrolyte solution comprises a lithium salt (to the concentration of 0.7-2.0 M); an organic solvent; and a vinyl ester-based compound represented by the formula 1, wherein R1, R2 and R3 are H, a primary, secondary or tertiary alkyl group, an alkenyl group or an aryl group. Preferably the lithium salt is at least one selected from the group consisting of LiPF6, LiBF4, LiClO4, LiCF3SO3, LiAsF6, LiN(CF3SO2)2 and LiN(C2F5SO2)2; and the organic solvent is a solvent mixture of a cyclic carbonate-based solvent and a chain carbonate-based solvent in the ratio of 1:1 to 1:9 by volume, or a solvent mixture of a carbonate-based solvent and a benzene-based solvent in the ratio of 1:1 to 10:1 by volume.