Recent Progress and Advances of High-entropy Polyanionic Cathodes in Lithium-ion and Sodium-ion batteries

Abstract

In recent years, research on lithium-ion and sodium-ion battery cathodes has advanced rapidly, with materials categorized into layered oxides, polyanionics, and Prussian blue analogues. Polyanionic cathodes stand out for sodium-ion batteries due to their structural stability, safety, and long cycle life, but face challenges in phase transition and property optimization. High-entropy doping emerges as a key strategy to enhance their electrochemical performance. This review first introduces the concept of high entropy and its stabilizing role in polyanionics, then outlines structural and electrochemical improvements via high-entropy doping, such as enhanced ion/electron transport and phase stability. Finally, the characteristics of high-entropy polyanionic cathodes for lithium-ion and sodium-ion batteries were summarized. In addition, we describe the challenges encountered in this research area as well as potential future directions for the implementation of high-entropy strategies in the field of polyanionic cathode materials.