| abstract |
An electrolyte solution for lithium ion secondary batteries, which contains an organic solvent containing a compound represented by formula (1), an electrolyte and an additive containing metal cations; and a lithium ion secondary battery which is provided with the electrolyte solution for lithium ion secondary batteries, a positive electrode and a negative electrode. In formula (1), each of R 1 , R 2 and R 3 independently represents a C 1 or C 2 alkyl group or a C 1 or C 2 alkoxyl group; and the metal cations are cations of one or more kinds selected from among K + , Rb + and Cs + . Examples of the additive include one or more salts selected from the group consisting of KSO 3 CF 3 and KN(SO 2 CF 3 ) 2 ) 2 . |