Patent ID: 9240616
Filing Date: 2016-01-19
CPC Classification: H01M,Y02E,Y02T

Claim Text:
1. A solvent for non-aqueous electrolytic solution of lithium secondary battery comprising a non-fluorine-containing cyclic carbonate (I), a non-fluorine-containing chain carbonate (II) and 1,2-dialkyl-1,2-difluoroethylene carbonate (III), wherein the non-fluorine-containing cyclic carbonate (I) is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate and vinylene carbonate, wherein the non-fluorine-containing chain carbonate (II) is at least one selected from the group consisting of diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate and methyl propyl carbonate; wherein the 1,2-dialkyl-1,2-difluoroethylene carbonate (III) is at least one selected from the group consisting of 1,2-dimethyl-1,2-difluoroethylene carbonate, 1,2-diethyl-1,2-difluoroethylene carbonate and 1-methyl-2-ethyl-1,2-difluoroethylene carbonate, and wherein when the total amount of (I), (II) and (III) is taken as 100% by volume, the non-fluorine-containing cyclic carbonate (I) is contained in an amount of 10 to 50% by volume, the non-fluorine-containing chain carbonate (II) is contained in an amount of 49.5 to 89.5% by volume, and the 1,2-dialkyl-1,2-difluoroethylene carbonate (III) is contained in an amount of not less than 0.5% by volume and less than 30% by volume.