Insights into chemical-mechanical degradation and modification strategies of layered oxide cathode materials of sodium ion batteries

Sodium-ion batteries (SIBs) have attracted significant attention in large-scale energy storage system because of their abundant sodium resource and cost-effectiveness. Layered oxide materials are particularly promising as SIBs cathodes due to their high theoretical capacities and facile synthesis. However, their practical applications are hindered by the limitations in energy density and cycling stability. The comprehensive understanding of failure mechanisms within bulk structure and at the cathode/electrolyte interface of cathodes is still lacking. In this review, the issues related to bulk phase degradation and surface degradation, such as irreversible phase transitions, cation migration, transition metal dissolution, air/moisture instability, intergranular cracking, interfacial reactions, and reactive oxygen loss, are discussed. The latest advances and strategies to improve the stability of layered oxide cathodes and full cells are provided, as well as our perspectives on the future development of SIBs. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.