Carrier transport in sulfur cathodes of all-solid-state lithium-sulfur batteries: Challenges, strategies, and characterizations

Abstract

All-solid-state lithium‑sulfur batteries (ASSLSBs) have emerged as promising candidates for next-generation energy storage systems due to their high energy density, excellent safety, and low cost. However, the inherently low electronic and ionic conductivity of sulfur, as well as inadequate solid-solid interfacial contact, leads to sluggish electrochemical reaction kinetics, severely impacting the electrochemical performance of ASSLSBs. To address these challenges, various modification strategies have been developed, focusing on improving charge carrier transport to enhance electrochemical activity and stability of the sulfur cathode. Here, we present a comprehensive review of the key electronic and ionic transport limitations in the sulfur cathode of ASSLSBs, along with the modification strategies and advanced characterization techniques. Finally, we highlight future research directions for the development of sulfur cathodes in realizing high-performance ASSLSBs.