Recent Progress Toward Practical Aqueous Zn‐I2 Batteries: From Lab to Practical

Abstract

Aqueous zinc‐iodine (Zn‐I 2 ) batteries are considered promising energy storage systems due to their low cost, high theoretical energy density, intrinsic safety and strong environmental adaptability. However, their practical application remains hindered by several challenges. At the I 2 cathode, soluble polyiodides are readily generated during charge and discharge, leading to severe shuttle effects, active material loss and self‐discharge. At the Zn anode, dendrite growth, hydrogen evolution, corrosion and by‐product formation compromise coulombic efficiency and cycling stability. Moreover, these challenges are intensified under high I 2 loading and in pouch cell configurations. Accordingly, this review systematically summarizes recent advances in physical confinement, chemical adsorption, supramolecular regulation, catalytic conversion, interfacial engineering and electrolyte engineering to address the associated limitations. On this basis, particular attention is devoted to the practical energy density and the underlying degradation mechanisms of aqueous Zn‐I 2 batteries under high iodine loading and pouch cell conditions, aiming to provide guidance for the rational design and practical application of durable aqueous Zn‐I 2 batteries with high energy density.