Chalcogenide-based inorganic sodium solid electrolytes

Abstract

All-solid-state sodium batteries (ASSSBs) are promising to be applied to large-scale energy storage systems due to the extensive source of raw materials, high safety, and high energy density. As one of the key materials for ASSSBs, sodium solid electrolytes (SSEs) have attracted significant attention in recent years. Therein, chalcogenide-based inorganic sodium solid electrolytes (ISSEs) stand out owing to their decent room temperature ionic conductivity and lower mechanical stiffness. The fundamental understanding of the structure–activity relationship is of great significance for guiding the design of chalcogenide-based ISSEs. In this review, we provide an overview of the research progress in chalcogenide-based ISSEs based on their crystal structures, synthetic methods, chemical/electrochemical properties, and structure–activity relationship, especially focusing on the perspective of crystal structure designs. We hope to provide some prospects and thoughts for the design of relevant solid electrolytes (SEs) in the future.