Interfacial Challenges and Strategies toward Practical Sulfide-Based Solid-State Lithium Batteries

All-solid-state lithium batteries are considered as the priority candidates for next-generation energy storage devices due to their better safety and higher energy density. As the key part of solid-state batteries, solid-state electrolytes have made certain research progress in recent years. Among the various types of solid-state electrolytes, sulfide electrolytes have received extensive attention because of their high room-temperature ionic conductivity and good moldability. However, sulfide-based solid-state batteries are still in the research stage. This situation is mainly due to the fact that the application of sulfide electrolytes still faces challenges in particular of interfacial issues, mainly including chemical and electrochemical instability, unstable interfacial reaction, and solid-solid physical contact between electrolyte and electrode. Here, this review provides a comprehensive summary of the existing interfacial issues in the fabrication of sulfide-based solid-state batteries. The in-depth mechanism of the interfacial issues and the current research progress of the main coping strategies are discussed in detail. Finally, we also present an outlook on the future development of sulfide-based solid-state batteries to guide the rational design of next-generation high-energy solid-state batteries.