Bridging the development of high-performance sodium-ion Batteries by designing high-entropy layered oxide cathodes

The rapid development of sodium-ion batteries (SIBs) for large-scale energy storage has spurred the emergence of various cathode materials. Layered oxides are promising candidates due to their high specific capacity and process compatibility, but complex phase transitions during cycling cause structural degradation and capacity decay. Among numerous optimization strategies, the high-entropy approach represents an innovative design concept. By introducing five or more principal elements and leveraging synergistic effects to modulate the crystal field environment and electronic structure, this strategy provides new perspectives to suppress phase transitions and enhance cycling stability. This review summarizes the structural characteristics of typical layered oxides, outlines the fundamentals of high-entropy design, and highlights recent progress and electrochemical advantages of high-entropy layered oxide cathodes for SIBs. Current challenges and opportunities are identified, and future research directions are outlined to guide rational design and practical implementation. In this work, the research progress of layered oxide cathode materials for sodium-ion batteries is comprehensively reviewed, focusing on high-entropy engineering from the perspective of entropy, which provides new ideas for the development of advanced cathodes. • The basic principles of high entropy strategy and its regulation mechanism on material properties are comprehensively analyzed. • The advantages of HEOs in stabilizing the crystal structure and improving the electrochemical performance of SIBs are systematically described. • The key challenges of HEOs faced by industrialization at present are pointed out, and a prospective solution centered on machine learning driven rational design is proposed.