Interfacial engineering of the layered oxide cathode materials for sodium-ion battery

The layered metal oxides are reviewed as the hopeful cathode materials for high-performance sodium-ion batteries (SIBs) due to their large theoretical capacity, favorable two-dimensional (2D) ion diffusion channel, and simple manipuility. However, their cycling stability, rate capability, and thermal stability are still significantly concerned and highlighted before further practical application. The chemical, mechanical and electrochemical stability of the cathode–electrolyte interfaces upon cycling is of great significance. Herein, the unique structural and electrochemical properties of the layered oxide cathode materials for SIB are reviewed. The mechanism of bulk/surface degradation induced by oxygen evolution, phase transition, microcrack, and electrolyte decomposition is thoroughly understood. Furthermore, the interfacial engineering to construct stable interface through various effective methods is fully discussed. The future outlook and challenges for interfacial engineering in this filed are also summarized. This review should shed light on the rational design and construct of robust interface for applications of superior layered oxide cathodes in SIB and may suggest future research directions.