Stability regulation of catalysts in Li-S batteries

Lithium‑sulfur batteries demonstrate significant potential for next-generation energy storage, owing to the high theoretical specific capacity of sulfur cathodes (1675 mAh g −1 ) and their energy storage mechanism based on chemical conversion reactions. However, their practical application is severely hindered by sluggish sulfur redox kinetics and the shuttle effect caused by soluble lithium polysulfides. In recent years, various catalytic materials have been employed as sulfur hosts and catalysts to accelerate sulfur conversion kinetics and suppress lithium polysulfide shuttling. Nevertheless, these materials often suffer from irreversible passivation and structural changes, leading to long-term performance degradation. This review systematically examines key factors limiting the stability of catalysts, including excessive adsorption of lithium polysulfides, passivation induced by insulating lithium sulfides, and surface structural reconstruction, clarifying how these contribute to capacity fade. Furthermore, we summarize effective strategies for achieving durable sulfur catalysis, focusing on the design of functionalized catalytic materials, such as constructing suitable support-catalyst interfaces, creating homogeneously distributed active sites, introducing co-catalysts to enhance electron transfer efficiency, and utilizing catalytic protective layers to suppress side reactions. Insights from these approaches will facilitate the development of stable and highly active catalytic systems, advancing the long-term stable operation of lithium‑sulfur batteries under practical conditions.