Electrocatalysts in zinc‑iodine batteries: theoretical insights and material design

Aqueous zinc‑iodine (Zn-I₂) batteries have emerged as a compelling solution for grid-scale electrochemical energy storage. Electrocatalysts are crucial to address the dilemma of Zn-I₂ batteries, especially in terms of the sluggish redox reaction kinetics and the deteriorative shuttle effect. A range of electrocatalysts has been developed to facilitate iodine conversion; however, their design concepts and catalytic mechanisms remain to be further understood. This review summarizes the current advances of electrocatalysts for Zn-I₂ batteries from theoretical insights to catalyst synthesis. Starting from the challenges, evaluation index and reaction mechanism, important achievements in metal-free and metal-based cathodic electrocatalytic materials are elaborated, providing an in-depth discussion of theoretical insights, design concepts, synthetic methods, and reaction mechanisms. Finally, the prospect for the development of electrocatalysts for Zn-I₂ batteries is envisioned. This review provides theoretical foundations and new guidance for designing advanced electrocatalysts and improving the electrochemical performance of Zn-I₂ batteries.