Ammonium Vanadate‐Based Cathodes for Practical Aqueous Zinc‐Ion Batteries: Mechanisms, Optimization, and Challenges

Abstract Aqueous zinc‐ion batteries (AZIBs) are developing into one of the most important battery technologies due to their high safety, low cost, and environmental friendliness. The key to their large‐scale application lies in the performance of cathode materials. Ammonium vanadate (NVO)‐based cathode materials exhibit excellent zinc storage performance that is as a result of their unique layers, controllable ion transport channels, and multi‐electron features, which make them superior to other cathode materials. However, the practical application of these materials is limited by a number of factors, such as unstable interlayer structures, poor intrinsic conductivity, slow Zn 2+ diffusion kinetics, and the production of by‐products. The purpose of this review is to clarify the structural characteristics as well as the zinc storage mechanisms of NVO‐based materials, and to analyze these key challenges in more detail. Furthermore, it systematically elaborates on the mechanism of action of these modification approaches, as well as their respective advantages and disadvantages. Last, it provides some insights into the research directions of NVO‐based materials in the field of AZIBs, providing new insights for the development of high‐performance cathodes for AZIBs, and making the industrialization of AZIBs possible.