Research progress of all-solid-state lithium–sulfur batteries with sulfide solid electrolytes: materials, interfaces, challenges, and prospects

Lithium–sulfur batteries (LSBs) have attracted much attention due to their high energy density, environmental friendliness and abundant natural reserves, and are considered a strong competitor for the next generation of energy storage devices. Significant research has been conducted on LSBs over the past decade; however, the inherent lithium polysulfide (LiPS) shuttle and lithium dendrite growth problems have been impossible to completely avoid for conventional liquid LSBs. The use of sulfide solid electrolytes (SEs) instead of organic liquid electrolytes can completely avoid the shuttle effect and mitigate the lithium dendrite growth problem due to the rigidity of sulfide SEs, but this does not mean that sulfide-based solid-state lithium–sulfur batteries (SSLSBs) are the optimal solution. For sulfide-based all-solid-state lithium–sulfur batteries (ASSLSBs), their inherent drawbacks, such as air sensitivity of the sulfide SE and narrow electrochemical stability window (ESW), mechanical–chemical failures caused by volume expansion of the active materials, and ineffective protection of the lithium metal anode, result in their commercial applications remaining challenging. To promote research and development of sulfide-based SSLSBs, this article reviews the electrochemical mechanisms of lithium–sulfur batteries, the defects and optimization strategies of sulfide SEs and reviews the recent developments in sulfide-based cathode materials, lithium-based anodes in sulfide-based SSLSBs, and their interface optimization and protection strategies. Finally, future development direction and prospects of ASSLSBs are analyzed.