Synergistic effect of sulfolane-based composite polymer electrolyte and vinylidene carbonate/lithium difluoro(oxalato)borate interface modification on LiCoO cathode.

LiCoO (LCO) is a prominent high-voltage cathode material due to its exceptional energy density and impressive theoretical specific capacity of 274 mAh g. However, challenges such as irreversible structural phase transitions, loss of reactive oxygen, and cobalt dissolution can lead to unstable interfaces between the electrolyte and the LCO cathode. In this study, sulfolane (SUL)-based composite polymer electrolytes (CPEs) were synthesized through in-situ polymerization, and the LCO cathode was modified using vinylidene carbonate (VC) and lithium difluoro(oxalato)borate (LiDFOB).