Challenges and optimization strategies at the interface between sulfide solid electrolyte and lithium anode

All-solid-state lithium batteries (ASSLB) based on sulfide solid electrolytes (SEs) have an energy density approximately four times higher than that of currently widely used lithium-ion batteries, and possess advantages in terms of processability and safety. They are widely recognized as one of the most promising new generation energy storage systems. The room-temperature ionic conductivity of sulfide SEs can reach up to 10−2 S cm−1, which is comparable to the ionic conductivity of liquid electrolyte. This makes them highly applicable, but during actual implementation in sulfide all-solid-state batteries, issues such as poor solid-solid interface contact, interface (electro)chemical side reactions, and interface lithium dendrite growth still exist. These greatly limit the application of sulfide SEs in the field of ASSLB. This article provides a detailed analysis of the interface problems between sulfide SEs/anode and summarizes the corresponding solution strategies, especially for the newly published literature, point by point for the first time. Finally, an outlook is made on the development prospects of sulfide-based ASSLB.