Intercalation chemistry has dominated electrochemical energy storage for decades, and storage capacity worldwide has now reached the terawatt-hour level. State-of-the-art intercalation cathodes for Li-ion batteries operate within the limits of transition metal cation electrochemistry, but the discovery of anion-redox processes in recent decades suggests rich opportunities for substantially increasing stored energy densities. The diversity of compounds that exhibit anion redox in the solid state has inspired the exploration of new materials for next-generation cathodes. In this Review, we outline the mechanisms proposed to contribute to anion redox and the accompanying kinetic pathways that can occur in layered transition metal oxides. We discuss the crucial role of structural changes at both the atomic and mesoscopic scales with an emphasis on their impact on electrochemical performance. We emphasize the need for an integrated approach to studying the evolution of both the bulk structure and electrode–electrolyte interphase by combining characterization with computation. Building on the fundamental understanding of electrochemical reaction mechanisms, we discuss engineering strategies such as composition design, surface protection and structural control to achieve stable anion redox for next-generation energy storage devices.

几十年来，插层化学一直主导着电化学储能，全球储能容量现已达到太瓦时水平。用于锂离子电池的最先进的插层阴极在过渡金属阳离子电化学的范围内运行，但近几十年来发现的阴离子氧化还原过程表明了大幅提高存储能量密度的丰富机会。在固态下表现出阴离子氧化还原的化合物的多样性激发了对下一代阴极新材料的探索。在这篇综述中，我们概述了有助于阴离子氧化还原的机制以及可能发生在层状过渡金属氧化物中的伴随动力学途径。我们讨论了原子和介观尺度上结构变化的关键作用，重点是它们对电化学性能的影响。我们强调需要一种综合方法，通过将表征与计算相结合来研究整体结构和电极-电解质界面的演变。基于对电化学反应机制的基本理解，我们讨论了诸如成分设计、表面保护和结构控制等工程策略，以实现下一代储能装置的稳定阴离子氧化还原。