Recent progress of sulfide electrolytes for all-solid-state lithium batteries

Solid electrolytes are recognized as being pivotal to next-generation energy storage technologies. Sulfide electrolytes with high ionic conductivity represent some of the most promising materials to realize high-energy-density all-solid-state lithium batteries. Due to their soft nature, sulfides possess good wettability against Li metal and their preparation process is relatively effortless. High cell-level sulfide-based all-solid-state lithium batteries have gradually been realized in recent years. However, there are still several disadvantages that sulfide electrolytes need to overcome, including their sensitivity to humid air and instability to electrodes. Herein, the recent progress for sulfide electrolytes, with particular attention given to electrolyte synthesis mechanisms, electrochemical and chemical stability, interphase stabilization and all-solid-state lithium batteries with high cell-level energy density, is presented.