Progress and prospect of the zinc–iodine battery

The zinc–iodine battery has the advantages of high energy density and low cost owing to the flexible multivalence changes of iodine and natural abundance of zinc resources. Compared with the flow battery, it has simpler components and more convenient installation, yet it still faces challenges in practical applications. How to select suitable materials as the cathode and electrolyte to control the process of energy storage reaction and inhibit the self-transformation of by-products, together with the corrosion resistance of metallic zinc are crucial factors. Herein, the principles of the zinc–iodine flow battery and zinc–iodine battery are described, and the unprecedented progresses are highlighted. This mini review is anticipated to provide valuable guidance for the further development of the zinc–iodine battery. The zinc–iodine flow battery and zinc–iodine battery are cost-effective and environmentally friendly electrochemical energy storage devices. They deliver high energy density owing to the flexible multivalence changes of iodine. In this mini review, the prominent problems of their modules (e.g. electrode, electrolyte) together with the common improvement strategies are described, which may provide valuable guidance for their further development.