Critical Problems and Modification Strategies of Realizing High‐Voltage LiCoO2 Cathode from Electrolyte Engineering

Abstract As the pursuit of greater energy density for the portable battery has stimulated exhaustive research in high‐voltage lithium‐ion batteries (LIBs), developing electrolyte additives is considered a cost‐efficient way to improve the performance of the battery. Here, the three interactional issues of LiCoO 2 (LCO) batteries in commercial electrolytes at high voltage are summarized, this review first identifies an unavoidable vicious cycle of the commercial electrolyte at high voltage. LCO/electrolyte interphase break, dissolution of transition metal (TM) ions, and formation of harmful HF accelerate the failing progress of the commercial electrolyte at high voltage, besides the malfunction of anode happens at the same time because of electrode crosstalk. Then, the modification of the commercial electrolyte is summarized according to the solutions of this vicious cycle. Last, a framework for future research on high‐voltage LCO batteries is outlined.