Patent ID: 9711825
Date: 2017-07-18
CPC Classifications: H01M,Y02E,Y02P,Y02T

Claim:
1. A lithium ion secondary battery comprising: a negative electrode comprising a negative electrode active material comprising at least two different carbons selected from the group of carbons consisting of natural graphite, artificial graphite, non-graphitizable carbon, and easily graphitizable carbon wherein at least one of the carbons of the negative electrode active material comprises massive non-graphitizable carbon; and an electrolyte solution comprising a cyclic sulfonic acid ester represented by the following formula (1): wherein, in the formula (1), R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or an amino group with the proviso that R 1 and R 2 are not hydrogen atoms at the same time; R 3 represents a linkage group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, a carbonyl group, a sulfonyl group, a fluoroalkylene group having 1 to 6 carbon atoms, and a divalent group having 2 to 6 carbon atoms in which alkylene units or fluoroalkylene units are bonded through an ether group.