Interfaces in Sulfide Solid Electrolyte-Based All-Solid-State Lithium Batteries: Characterization, Mechanism and Strategy

Owing to the advantages of high energy density and environmental friendliness, lithium-ion batteries (LIBs) have been widely used as power sources in electric vehicles, energy storage systems and other devices. Conventional LIBs composed of liquid electrolytes (LEs) have potential safety hazards; thermal runaway easily leads to battery explosion and spontaneous combustion. To realize a large-scale energy storage system with higher safety and higher energy density, replacing LEs with solid-state electrolytes (SSEs) has been pursued. Among the many SSEs, sulfide SSEs are attractive because of their high ionic conductivities, easy processabilities and high thermostabilities. However, interfacial issues (interfacial reactions, chemomechanical failure, lithium dendrite formation, etc.) between sulfide SSEs and electrodes are factors limiting widespread application. In addition, the intrinsic interfacial issues of sulfide SSEs (electrochemical windows, diffusion mechanisms of Li + , etc.) should not be ignored. In this review, the behaviors, properties and mechanisms of interfaces in all-solid-state lithium batteries with a variety of sulfide SSEs are comprehensively summarized. Additionally, recent research progress on advanced characterization methods and designs used to stabilize interfaces is discussed. Finally, outlooks, challenges and possible interface engineering strategies are analyzed and proposed. Graphical Abstract