Zinc-iodine batteries with high polyiodide adsorption and utilisation in low-cost electrochemical iron platform alleviating polyiodide shuttling

Aqueous zinc‑iodine (Znsingle bondI₂) batteries herald huge potential for energy storage devices because of the constitutional safety of the zinc anode and attractive energy density. However, cathode hosts with low iodide utilisation and adsorption, sluggish redox kinetics, lengthy and costly fabrication process impede their scalability and electrochemical performance. Herein, we propose a low-cost electrochemical iron-based cathode to expand the Znsingle bondI₂ battery's electrochemical performance by harnessing iron earth richness, high conductivity and redox versatility. A straightforward and scalable electrodeposition approach is demonstrated at room temperature to fabricate AC-FeOOH cathode iodine host. The assembled Znsingle bondI₂ cell for AC-FeOOH | | Zn device displayed an excellent capacity of ∼ 0.56 mAh cm−2 at 2 mA cm−2. The outstanding performance of the AC-FeOOH based device corresponds to the integration of FeOOH on the matrix of AC, which enhances the iodide adsorption and utilisation, alleviating the polyiodide shutting effect and Zn anode corrosion. The present technique provides a cost-effective route to employ iron for Znsingle bondI₂ battery systems, making the process more economical for grid-scale energy storage applications, delivering a sustainable route for alleviating the shortcomings of Znsingle bondI₂ battery system, and paving way for their implementation in wider areas in the electrochemical energy storage devices.