Patent ID: 7709155

Claim:
A nonaqueous electrolytic solution including a nonaqueous solvent and a lithium salt soluble in the nonaqueous solvent; wherein the nonaqueous solvent contains propylene carbonate, a first compound expressed by the following general formula (I), and a second compound expressed by the following general formula (II); wherein the content of propylene carbonate in the nonaqueous solvent is at least 10 volume %; and wherein the content X [mass %] of the first compound and the content Y [mass %] of the second compound simultaneously satisfy the conditions represented by the following expressions (1) and (2): 2≦( X+Y )≦8 (1) 0.02≦( Y/X )≦0.25 (2) where R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are either identical to or different from each other, indicating any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 3; where R 7 and R 8 are either identical to or different from each other, indicating any of a hydrogen atom and hydrocarbon groups having a carbon number of 1 to 6.