Modification strategy for advanced Mn-based layered transition metal oxide cathode for sodium-ion batteries

Sodium-ion batteries (SIBs) are being touted as the future of energy storage. However, the lackluster performance of current cathode technology is a major roadblock to their widespread use. Among the promising candidates for cathodes, layered sodium manganese oxide stands out due to its low cost and higher energy density. However, its cycling performance is limited due to structural and surface instabilities. To overcome these challenges, researchers are exploring various strategies, such as doping, coating, and heterostructure design, to enhance the performance of manganese-based oxide. Doping involves introducing foreign atoms to enhance structural stability and electrochemical performance. Coating is a surface protection method, while heterostructure design involves developing a composite material composed of different crystal phases of sodium manganese oxide to leverage the intrinsic advantage of each phase. This review introduces the existing challenges of layered sodium manganese oxide and provides a comprehensive understanding of reported strategies and their potential for improving the performance of this material. By analyzing the latest research, we hope to contribute to the development of practical and scalable SIBs.