Interface problems, modification strategies and prospects of Ni-rich layered oxide cathode materials in all-solid-state lithium batteries with sulfide electrolytes

All-solid-state lithium batteries (ASSLBs) using sulfide solid electrolytes (SSEs) have triggered extensive atten-tions in both academia and industry due to the feasibility of effectuating high safety and high energy density, compared with liquid-type batteries. Cathode materials with high voltage and prominent specific capacity are urgently needed for realizing lithium batteries with high energy density. Among multitudinous cathode materials studied by researchers, Ni-rich layered oxide cathode materials are considered to be one of the most promising applications in ASSLBs due to high operating voltage, superior reversible capacity and low production cost. However, their physical, chemical, and electrochemical performances in ASSLBs, especially the long-life ca-pacity, are still insufficient to gratify market requirements for electric vehicles, and the targeted review for Ni-rich layered oxide cathodes in ASSLBs is rare. Herein, we comprehensively summarize these issues of the interfacial physical connection, chemical/electrochemical reactions, and space-charge layer (SCL) of Ni-rich layered oxide cathodes in ASSLBs with SSEs. Moreover, the modification strategies of Ni-rich layered oxide cathode materials to address the aforementioned issues are focused on. In the end, the future development di-rection of ASSLBs using Ni-rich oxide cathodes and SSEs is briefly discussed.

Automated summary

All-solid-state lithium batteries (ASSLBs) with sulfide solid electrolytes (SSEs) have gained attention for their high safety and energy density. Ni-rich layered oxide cathode materials show promise in ASSLBs due to their high voltage, reversible capacity, and low cost. However, their performances, especially long-life capacity, are insufficient for electric vehicles. This review summarizes the issues of physical connection, chemical/electrochemical reactions, and space-charge layer (SCL) of Ni-rich layered oxide cathodes in ASSLBs with SSEs, as well as the modification strategies to address these issues. The future development direction of ASSLBs using Ni-rich oxide cathodes and SSEs is also discussed briefly.