Solid‐State Electrolytes in Lithium–Sulfur Batteries: Latest Progresses and Prospects

Abstract Solid‐state lithium–sulfur batteries (SSLSBs) have attracted tremendous research interest due to their large theoretical energy density and high safety, which are highly important indicators for the development of next‐generation energy storage devices. Particularly, safety and “shuttle effect” issues originating from volatile and flammable liquid organic electrolytes can be fully mitigated by switching to a solid‐state configuration. However, their road to thecommercial application is still plagued with numerous challenges, most notably the intrinsic electrochemical instability of solid‐state electrolytes (SSEs) materials and their interfacial compatibility with electrodes and electrolytes. In this review, a critical discussion on the key issues and problems of different types of SSEs as well as the corresponding optimization strategies are first highlighted. Then, the state‐of‐the‐art preparation methods and properties of different kinds of SSE materials, and their manufacture, characterization and performance in SSLSBs are summarized in detail. Finally, a scientific outlook for the future development of SSEs and the avenue to commercial application of SSLSBs is also proposed.