Abstract:

Solid-state lithium-sulfur (Li-S) batteries replace the traditional liquid electrolyte system with solid-state electrolyte, which is expected to solve the serious problems of the shuttle effect of polysulfide, the side reaction between lithium metal and liquid electrolyte, poor safety performance in liquid electrolyte-based Li-S batteries. However, solid-state Li-S batteries still face great challenges in terms of the selection of solid-state electrolyte and electrode/electrolyte interfaces. Herein, we review recently studies on the applications of sulfide solid electrolyte and polymer matrix electrolyte, and analyze the electrode/electrolyte interfacial contact issues in the solid-state Li-S batteries. The (electro-)chemical stabilization approaches to solve the intrinsic defects in sulfide solid electrolytes, and the properties of organic polymer electrolytes and ionic conductivity enhancement methods are detailedly summarized. We also demonstrate the intrinsic properties buried in the electrode/electrolyte interfaces that limit the capacity delivering. Recently reported corresponding approaches to suppress these serious problems are further reviewed, especially related to the sluggish reaction kinetics on the interfaces. In the last section, we point out that intrinsic defects of different electrolytes should be addressed critically, and it is of great significance for the practical application of solid-state Li-S batteries to further study the interface transport mechanism and design the electrode/electrolyte interface structure reasonably in practice.

Key words: solid-state lithium-sulfur batteries, solid/solid interface, solid-state electrolyte, electrochemical performance