Recent Advances in Interfacial Chemistry for Solid‐State Lithium–Sulfur Batteries

ABSTRACT All‐solid‐state Lithium–sulfur batteries (ASSLSBs) have emerged as a highly promising candidate for next‐generation energy storage systems, featuring a unique combination of earth‐abundant sulfur cathodes, high‐capacity lithium metal anodes, and nonflammable solid‐state electrolytes (SSEs). These components collectively circumvent the energy density limitations (<300 Wh kg −1 ) and safety concerns for the conventional liquid electrolyte‐based lithium‐ion batteries. However, the high impedances at the SSEs/electrode interfaces, at both Li anodes and sulfur cathodes, impede efficient charge transfer and Li stripping/plating kinetics, indicating a critical bottleneck. This review focuses on the mechanistic dynamics governing these solid‐state interfaces. We provide an in‐depth analysis of the origin and evolution of SSEs/electrode interfaces and their impact on the electrochemical performance. Furthermore, we systematically evaluate state‐of‐the‐art strategies for deciphering solid‐state sulfur conversion reactions and Li plating/stripping processes, as well as for enhancing the interfacial stability and reaction kinetics. Finally, we examine the gap between current achievements in laboratories and the industrial requirements for practical ASSLSBs, followed by actionable perspectives. This review is expected to provide valuable insights for solid‐state battery community and facilitate the realization of high‐performance ASSLSBs.