Electrolytes for high-voltage lithium batteries

In the aim of achieving higher energy density in lithium (Li) ion batteries (LIBs), both industry and academia show great interest in developing high-voltage LIBs (>4.3 V). However, increasing the charge cutoff voltage of the commercial LIBs causes severe degradation of both the positive electrode materials and conventional LiPF₆-oragnocarbonate electrolytes. Consequently, LIBs using conventional LiPF₆-organocarbonate electrolytes suffer from a short cycle life when operated at higher charge cutoff voltages. In this review, the aging mechanisms associated with high-voltage LIBs are analyzed, and the countermeasures from the electrolyte design are discussed.