Review on interface issues of Li-argyrodite-based solid-state Li-metal batteries

Abstract

Sulfide solid electrolyte-based all-solid-state batteries (ASSBs) offer increased safety, extended cycle life, reduced cost, and increased energy and power density. However, sulfide-based electrolytes exhibit poor interface stability when they contact active materials (anodes or cathodes). The issues of low capacity, inefficient coulombic efficiency, huge polarization, and capacity decay in ASSBs are primarily attributed to sluggish charge transfer kinetics at the interface caused by chemical interactions, electrochemical degradation, weakening interfacial mechanical integrity, etc. Identifying the factors that affect the interfaces, studying the properties of interfaces, and proposing a mechanism to solve the problem are very important, as these properties directly or indirectly impact battery performance. Although the precise mechanism underlying these interface issues remains incompletely understood, combining chemo-mechanical processes and physical and (electro)chemical properties regulate the charge transfer phenomena at the interfaces. In this review, we identify the factors that affect the interfacial phenomena and properties of Li-argyrodite-based ASSBs. Analytical tools are introduced to study interfacial stabilities, changes, and mechanism behind. Finally, we summarize the strategies and propose future perspectives to advance Li-argyrodite-based ASSBS.