Li metal anode interface in sulfide-based all-solid-state Li batteries

Sulfide solid electrolyte (SSE)-based all-solid-state Li batteries (ASSLBs) can overcome the problems of low energy density and safety concern of current Li-ion batteries. However, the practical application of SSE-based ASSLBs is suffered from several problems, especially interfacial issues between Li metal anode (LMA) and SSEs. Therefore, in this study, the problems of the LMA-SSE interface and their corresponding solutions are reviewed. First, the interfacial problems are summarized, namely the side reactions of SSEs, the Li dendrite growth, and poor contact between the electrode and electrolyte. Second, the available strategies to improve the robustness of the interface are discussed, including the protection of the LMA, substitution of the LMA, and modification of SSEs. Third, the characterization methods used to analyze the morphological and compositional evolution of the interface during cycling are introduced. Finally, the limitations and future research directions are proposed.