Cathodic interface in sulfide-based all-solid-state lithium batteries

All-solid-state lithium batteries (ASSLBs) have garnered significant research attention due to their unparalleled safety features and impressive energy density. Among the solid electrolytes, the sulfide solid electrolytes (SSEs) have emerged as particularly popular. This is largely attributed to their commendable ionic conductivity, and moderate mechanical stiffness. However, the seamless integration between electrode materials and SSEs has posed considerable challenges, particularly concerning the interface connecting high-voltage oxide cathodes and SSEs. A comprehensive comprehension of the factors contributing to interfacial degradation assumes paramount importance in rectifying these interface-related issues. In this comprehensive review, we delve into the intricacies of interfacial instability arising from chemical, electrochemical, and mechanical sources between cathodes and SSEs. Additionally, we meticulously examine the evolution of cathodic interfaces, subjecting them to thorough theoretical analysis. Simultaneously, we compile a compendium of optimization strategies aimed at enhancing the interface. These strategies encompass diverse facets, spanning from electrolyte/cathode material modification to advancements in electrolyte/cathode layer fabrication technology. Concluding our discourse, we address the challenges and predicaments encountered in this swiftly evolving domain. Our ultimate objective remains the facilitation of ASSLB development characterized by exceptional energy density and an impeccable safety profile.