Spin‐Electrochemistry of Transition Metal Oxides for Energy Storage: Concepts, Advances and Perspectives

Abstract Developing high‐capacity and cyclically stable transition metal (TM)‐based electrode materials for energy storage devices, such as aqueous ion energy storage systems, is crucial for addressing the growing issue of energy scarcity. The spin state, or spin configuration of the d‐electrons, plays a vital role in the electrochemical energy storage performance of these materials. However, there has been a lack of systematic descriptions regarding the role of spin configurations in electrochemical energy storage to date. This review aims to elucidate the advantages of controlling the spin states of metal centers to enhance energy storage performance and highlights recent progress in employing spin state regulation in electrochemical energy storage. Additionally, it covers the various characterization techniques used to determine spin states. Finally, we discuss the future prospects and challenges within this emerging field, with the aim of accelerating the development of spin‐based electrochemical energy storage technologies. This review also seeks to provide clear and reliable directions for the design and preparation of novel energy storage materials.