ELECTROLYTIC SOLUTION FOR LITHIUM ION SECONDARY BATTERIES AND LITHIUM ION SECONDARY BATTERY ARRANGED BY USE THEREOF

PROBLEM TO BE SOLVED: To provide: an electrolytic solution for lithium ion secondary batteries which enables the formation of a lithium ion secondary battery superior in rate characteristic; and a lithium ion secondary battery arranged by use of such an electrolytic solution.SOLUTION: The means for solving the problem is an electrolytic solution for lithium ion secondary batteries which comprises an ordinary temperature molten salt and an electrolyte. The ordinary temperature molten salt is a sulfonium salt. In the electrolytic solution, the content of anions expressed by the formula (1) is less than 100 ppm in total.SELECTED DRAWING: None 【課題】本発明の課題は、レート特性に優れたリチウムイオン二次電池を構成できるリチウムイオン二次電池用電解液およびこれを用いたリチウムイオン二次電池を提供することである。【解決手段】解決手段は、常温溶融塩と電解質とを有するリチウムイオン二次電池用電解液であって、前記常温溶融塩がスルホニウム塩であり、電解液中の式（１）で示されるアニオンの含有量の合計が１００ｐｐｍ未満であるリチウムイオン二次電池用電解液。【選択図】なし