Electrolyte Additive Strategies in Aqueous Zn-Ion Batteries: Recent Advances and Prospects

Aqueous zinc ion batteries (AZIBs) are considered one of the most promising energy storage systems due to their environmental friendliness, the intrinsic safety, and the abundance of Zn resources. However, using aqueous electrolytes presents many challenges for AZIBs, such as Zn dendrites, side reactions, and active material dissolution. Among the many solutions, electrolyte additives have emerged as a focal point in recent research due to their flexible structure, low cost, and strong regulating ability. Current discourse predominantly centers on the effect of additives on the electrode and electrode/electrolyte interface of AZIBs, while systematic evaluation and future perspectives on the types of additives remain underexplored. Therefore, it is necessary to systematically summarize electrolyte additive engineering and to further explore unresolved challenges. This review provides a comprehensive overview of electrolyte additives organized around three functional directions and presents the recent progress and representative strategies for anode protection additives, cathode stabilization additives, and electrolyte regulation additives. Finally, the paper summarizes the key issues in current research and looks at future directions. This paper aims to provide a theoretical foundation and practical guide for the research and application of high-performance and long-life AZIBs.