Insight into All-Solid-State Li–S Batteries: Challenges, Advances, and Engineering Design

The advancement of conventional lithium–sulfur batteries (LSBs) is hindered by the shuttle effect and corresponding safety issues. All-solid-state lithium–sulfur batteries (ASSLSBs) substitute the liquid electrolytes with solid-state electrolytes (SEs) to completely isolate the cathode and anode, thereby effectively suppressing polysulfide migration and growth while significantly enhancing energy density and safety. However, the development of ASSLSBs is accompanied by several challenges such as the formation of Li dendrites, electrode degradation, poor interfacial wettability, and sluggish reaction kinetics, etc. This review systematically summarizes the recent advancements made in ASSLSBs. First, a comprehensive overview of the research conducted on advanced cathodes utilizing sulfur (S) and lithium sulfide (Li₂S) is displayed. Subsequently, the SEs are classified and discussed that have been implemented in ASSLSBs. Furthermore, the issues of interfaces and anodes in ASSLSBs are analyzed. Finally, based on current laboratory advancements, rational design guidelines are proposed for each component of ASSLSBs while also presenting four practical recommendations for facilitating early commercialization.