Interfacial Degradation and Optimization of Li‐rich Cathode Materials†

Abstract High‐energy and safe lithium ion batteries (LIBs) are in increasing need as the rapid development of electronic devices, electric vehicles, as well as energy storage station. Li‐rich oxides have attracted a lot of attention due to their high capacity and low cost as cathode material for LIBs. However, they still suffer from the vulnerable cathode/ electrolyte interface, which presents the huge challenges of surface degradation and gas release, particularly at high state of charge. Some issues of Li‐rich cathode materials, such as moderate cycle stability and voltage decay, are in tight connection with electrode‐electrolyte interfacial side reactions. Research in the area of interfacial degradation mechanism and optimization strategies is of great significance as for Li‐rich cathode, and extensive efforts have been poured. This review aims to understand the degradation mechanism of Li‐rich cathode materials, and summarize the corresponding valuable and effective optimization strategies. Based on these considerations, we also have discussed the remaining challenges and the future research direction.