| abstract |
Disclosed is an electrolyte solution having a high electrolyte salt concentration, in which cycle characteristics are unlikely to deteriorate, and the battery life performance can be improved, and a lithium ion secondary battery using the electrolyte solution. An electrolyte solution of the present invention includes an electrolyte salt and a solvent, the electrolyte salt concentration is more than 1.1 mol / L, and the electrolyte salt includes a compound represented by the following general formula (1): And a cyclic carbonate is included as a solvent. (XSO2) (FSO2) NLi (1) (In the general formula (1), X represents a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms). 1 |