Liquid-phase synthesis of a series of superionic sulfide electrolytes for all-solid-state lithium-sulfur battery

Inorganic solid electrolytes offer transformative opportunities for next-generation lithium batteries by enabling new chemistries and cell architectures. Among them, sulfide electrolytes are particularly attractive due to their high ionic conductivity and favorable mechanical processability. However, scalable synthesis of sulfide electrolytes with high ionic conductivity remains a significant bottleneck. Here, we report a liquid-phase synthesis platform based on a Li2S-SiS2-P2S5 ternary system, capable of producing electrolytes with high ionic conductivity at kilogram scale. Beyond fast ionic transport kinetics, the electrolytes prepared via this platform function effectively as catholytes for high-loading sulfur electrodes, promoting uniform ion transport and enhanced electrochemical kinetics. Building on this approach, a Li2S-SiS2-P2S5-LiI quaternary system is developed to produce lithium-metal compatible anolytes. As a result, we realize a long-cycling all-solid-state lithium-sulfur battery in which the catholyte, interlayer, and anolyte are all synthesized via liquid-phase methods. This work proposes a scalable route for producing sulfide electrolytes, potentially contributing to the industrial development of all-solid-state batteries. Sulfide electrolytes are promising candidates for solid-state batteries, but their scalable production remains challenging. Here, the authors develop a kilogram-scale liquid-phase synthesis platform for sulfide electrolytes used across all key components in all-solid-state lithium–sulfur batteries.