Recent Advances for High-Entropy based Layered Cathodes for Sodium Ion Batteries.

In recent years, layered oxides have been extensively studied as promising cathode materials for sodium ion batteries. However, layered oxides undergo complex phase transitions during charge-discharge process, which adversely affects the electrochemical performance. High-entropy layered oxides as a unique design concept can effectively improve the cycling performance of cathode materials by virtue of the 2D ion migration channels between the layers. Based on the concepts of high-entropy and layered oxides, this paper reviews the research status of high-entropy layered oxides in the field of sodium-ion batteries, focusing on the connection between high-entropy and layered oxide phase transitions during electrochemical charging and discharging. Finally, the advantages of layered cathode materials based high-entropy are summarized, and the opportunities and challenges of future high-entropy layered materials are proposed.