Solid-state electrolytes for solid-state lithium-sulfur batteries: Comparisons, advances and prospects

Compared with other secondary batteries, lithium-sulfur batteries (LSBs) have unparalleled advantages such as high energy density, low cost, etc. In liquid LSB systems, it is extremely easy to cause severe “shuttle effect” and safety issues. Hence, the development of solid-state LSBs (SSLSBs) has been attracting much more attention. As the most essential part of the SSLSBs, the solid-state electrolyte (SSE) has received significant attention from researchers. In this review, we concentrate on discussing the core of SSLSBs, which is the SSE. Moreover, we also highlight the differences in the properties of the different SSEs, which are polymer-based electrolytes and ceramic-based electrolytes. In addition, the challenges and advances in different types of SSEs are also compared and described systematically. Furthermore, the prospects for new SSE systems and the design of effective SSE structures to achieve high-performance SSLSBs are also discussed. Thus, this review is expected to give readers a comprehensive and systematic understanding of SSEs for SSLSBs.