Acetonitrile electrolyte containing high-concentration metal salt and secondary battery containing the electrolyte

摘要

[Problem] The present invention addresses the problem of providing a novel electrolyte solution system for lithium secondary batteries. [Solution] An electrolyte solution for lithium secondary batteries, which contains acetonitrile and LiN(SO2F)2, and which is characterized in that the molar volume concentration of the LiN(SO2F)2 in the electrolyte solution is 3.0 mol/L or more.