| CPC H01M 10/0569 (2013.01) [H01M 10/0525 (2013.01); H01M 2300/0028 (2013.01)] | 9 Claims |

|
1. A secondary battery comprising:
a positive electrode having a potential, versus a lithium reference electrode, at a time of charging higher than or equal to 4.50 volts;
a negative electrode; and
an electrolytic solution including a branched carboxylic acid ester compound represented by Formula (1),
![]() where
R1 is a first alkyl group,
R2 is a second alkyl group,
R3 is a hydrogen group,
R4 is one of a third alkyl group or a halogenated alkyl group, and
a total of a carbon number of R1, a carbon number of R2, and a carbon number of R3 is 2 or 3.
|