Interface compatibility between sulfide solid electrolytes and Ni-rich oxide cathode materials: factors, modification, perspectives

All-solid-state batteries (ASSBs) assembled with sulfide solid electrolytes (SSEs) and nickel (Ni)-rich oxide cathode materials are expected to achieve high energy density and safety, representing potential candidates for the next-generation energy storage systems. However, interfacial issues between SSEs and Ni-rich oxide cathode materials, attributed to space charge layer, interfacial side reactions, and mechanical contact failure, significantly restrict the performances of ASSBs. The interface degradation is closely related to the components of the composite cathode and the process of electrode fabrication. Focusing on the influencing factors of interface compatibility between SSEs and Ni-rich oxide cathode, this article systematically discusses how cathode active materials (CAMs), electrolytes, conductive additives, binders, and electrode fabrication impact the interface compatibility. In addition, the strategies for the compatibility modification are reviewed. Furthermore, the challenges and prospects of intensive research on the degradation and modification of the SSE/Ni-rich cathode material interface are discussed. This review is intended to inspire the development of high-energy-density and high-safety all-solid-state batteries.