Qianqin Zhou, Fan Zhang, Ting Liao, Ziqi Sun
ABSTRACT Aqueous zinc‐iodine (Zn‐I 2 ) batteries have gained considerable attention as safe, low‐cost energy‐storage systems, yet several intrinsic limitations continue to impede their widespread application. Major challenges associated with electrolytes, such as restricted energy density, sluggish iodine redox kinetics, dissolution of iodine species, and polyiodide shuttling, however, are considered as central bottlenecks. This review provides an integrated summary of recent developments in Zn‐I 2 battery chemistry and summarizes the electrolyte engineering strategies on accounting to different electrons transfer mechanisms in Zn‐I 2 redox chemistry. In this section, special focuses are paid on the rational design of aqueous electrolytes in balancing the iodine solubility, the polyiodide complexation, the electrolyte acidity/alkalinity, and the Zn 2+ coordination chemistry. Finally, a research outlook and a few design principles in suppressing uncontrolled shuttle and redox instability of polyiodide species while simultaneously maintaining high Zn reversibility are proposed for achieving high‐performance and durable Zn‐I 2 systems. This review aims to provide a feasible framework for advancing Zn‐I 2 battery electrochemistry and accelerating their transition toward practical, large‐scale energy‐storage applications.