Solid Electrolyte Interphase Architecture for a Stable Li‐electrolyte Interface

Abstract Li metal anode has attracted extensive attention as the state‐of‐the‐art anode material for rechargeable batteries. It is defined as the ultimate anode material for the high theoretical specific capacity (3860 mAh g−1) and the lowest negative electrochemical potential (−3.04 V vs. Standard Hydrogen Electrode). However, the uncontrolled Li dendrites and the spontaneous side reactions between Li and electrolytes hinder its commercialization. To overcome these obstacles, the optimized solid electrolyte interphase (SEI) with excellent performance was proposed by the artificial method. The improved performance includes high stability, ionic conductivity, compactness, and flexibility. In this review, the strategies for artificial SEI engineering in liquid and solid electrolytes are summarized. To fabricate an ideal artificial SEI, the component, distribution, and structure should be fully and reasonably considered. This review will also provide perspectives for the SEI design and lay a foundation for the future research and development of Li metal batteries.