From Conventional Two‐Electron to Emerging Multi‐Electron Zinc‐Iodine Batteries: Advantages, Challenges, and Future Perspectives

This review highlights the progress and challenges in the development of aqueous zinc‐iodine batteries (ZiBs), emphasizing the shift from traditional two‐electron systems to advanced multi‐electron configurations. ZiBs are promising due to their abundant raw materials, environmental sustainability, and high theoretical capacity. However, issues like the polyiodide shuttle effect and zinc dendrite formation impede performance and stability. Recent advances in polar materials, catalysts, separators, and iodine‐anchoring compounds aim to enhance cycle life, specific capacity, and discharge voltage. Multi‐electron ZiBs, utilizing higher iodine oxidation states, offer improved energy density and efficiency, with innovations such as halide ions and organic molecules stabilizing high‐valence iodine species for enhanced electron transfer. Future directions include functional group engineering, stabilization of iodine species, material optimization, and AI‐assisted integration, enhancing energy density, lifespan, and cost‐effectiveness for large‐scale and portable applications.