Modified cathode-electrolyte interphase toward high-performance batteries

A stable and uniform cathode-electrolyte interphase (CEI) is extremely important for rechargeable batteries with high energy densities and long life cycles. The CEI greatly influences the electro-chemical reactions at the interphase while stabilizing the cathode's structure. Because of the complexity of the interfacial reaction, an overall picture of CEI evolution and effective analysis methods is ab-sent in the field. Herein, the formation and evolution mechanism of the CEI in rechargeable batteries are reviewed based on the CEI studies. Diverse advanced characterization methods for the interfa-cial reaction are also summarized. Subsequently, modified strate-gies to enhance the stability of the CEI are introduced, such as CEI-forming additives in electrolytes, localized high-concentration electrolytes, artificial CEIs, and solid-state electrolyte engineering. Finally, challenges and future directions for the CEI are proposed. We hope this review sheds light on future research on CEI layers.