KFSA/glyme electrolytes for 4 V-class K-ion batteries

Highly concentrated electrolytes of KN(SO2F)(2) (KFSA)/diglyme and KFSA/triglyme are developed for high-voltage K-ion batteries. They demonstrate high oxidation stability up to 4.7 V vs. K/K+, which is considerably higher than that of the KFSA/monoglyme electrolyte. Moreover, these electrolytes can improve the cycling stability of high-voltage K-ion batteries.