Synthesis‐Structure‐Property of High‐Entropy Layered Oxide Cathode for Li/Na/K‐Ion Batteries

Increasing demand for rechargeable batteries necessitates improvements in electrochemical performance. Traditional optimal approaches such as elemental doping and surface modification are insufficient for practical applications of the batteries. High-entropy materials (HEMs) possess stable solid-state phases and unparalleled flexibility in composition and electronic structure, which facilitate rapid advancements in battery materials. This review demonstrates the properties of HEMs both qualitatively and quantitatively, and the mechanisms of their enhancement on battery properties. It also illustrates the progress in high-entropy layered oxide cathode materials (HELOs) for lithium/sodium/potassium ion batteries (LIBs/SIBs/PIBs) in the perspectives of synthesis, characterization and application, and elucidating the synthesis-structure-property relationship. Furthermore, it outlines future directions for high-entropy strategies in battery study: precise synthesis control, understanding of reaction mechanisms through structural characterization, elucidation of structure-performance correlations, and the computational and experimental methods integration for rapid screening and analysis of HEMs. The perspective aims to inspire researchers in the development of high-performance rechargeable batteries.