Non-aqueous electrolyte and lithium secondary battery using the same

摘要

The present invention provides non-aqueous electrolyte solution for a lithium secondary battery, comprising an ester-based compound having a branched-chain alkyl group and an ester-based compound having a straight-chain alkyl group; and a lithium secondary battery using the same.

主权项

1. A non-aqueous electrolyte solution for a lithium secondary battery, comprising an electrolyte salt and an organic solvent, wherein the non-aqueous electrolyte solution further comprises a first ester-based compound having the following formula (I) and a second ester-based compound having the following formula (II), and the amount of the first and the second ester-based compounds is in the range of 50 to 90 vol % based on the total volume of the organic solvent, the first ester-based compound and the second ester-based compound; and
wherein a radical-transfer reaction occurs between the first ester-based compound and the second ester-based compound: wherein, R1 is straight- or branched-chain alkyl group having 1 to 10 carbon atoms, R2 is isoalkyl group having 3 to 8 carbon atoms, sec-alkyl group having 4 to 8 carbon atoms or tert-alkyl group having 4 to 8 carbon atoms; wherein, R3 and R4 are straight-chain alkyl group having 1 to 10 carbon atoms, and the volume mixing ratio (a:b) of the first ester-based compound (a) and the second ester-based compound (b) is 80:20 to 20:80.