Insights into interfacial physiochemistry in sulfide solid-state batteries: a review

The pursuit of high-energy-density and safe energy storage has propelled the development of all-solid-state battery systems as the most promising pathway. In order to achieve this objective, it is of utmost importance to identify solid-state electrolytes that exhibit both exceptional ionic conductivity and structural stability during battery operation. Among solid electrolytes, sulfide-based electrolytes have demonstrated a level of ionic conductivity comparable to liquid electrolytes, positioning them as the most promising candidates for solid-state batteries. However, sulfide-based all-solid-state batteries often encounter significant impedance at the electrode-electrolyte interfaces due to poor physical contact and unfavorable (electro)chemical reactions. To address this challenge, a number of studies have been conducted to explore the physiochemical behaviors at these interfaces. This review specifically focuses on the evolutionary processes occurring at the interfacial level, aiming to provide a comprehensive understanding of the underlying degradation mechanisms. Additionally, we consolidate effective strategies for mitigating the interfacial degradations during battery operation, while also discussing the prospects and insights regarding interfacial issues and further advancement of all-solid-state battery systems. We believe this review will pave the way for the design and architecture of safe electrochemical energy storage systems.