Critical Review on cathode-electrolyte Interphase Toward High-Voltage Cathodes for Li-Ion Batteries

The thermal stability window of current commercial carbonate-based electrolytes is no longer sufficient to meet the ever-increasing cathode working voltage requirements of high energy density lithium-ion batteries.It is crucial to construct a robust cathode-electrolyte interphase(CEI)for high-voltage cathode electrodes to separate the electrolytes from the active cathode materials and thereby suppress the side reactions.Herein,this review presents a brief historic evolution of the mechanism of CEI formation and compositions,the state-of-art characterizations and modeling associated with CEI,and how to construct robust CEI from a practical electrolyte design perspective.The focus on electrolyte design is categorized into three parts:CEI-forming additives,anti-oxidation solvents,and lithium salts.Moreover,practical considerations for electrolyte design applications are proposed.This review will shed light on the future electrolyte design which enables aggressive high-voltage cathodes.