Aqueous rechargeable zinc–iodine batteries are emerging high-safety and cost-effective technology for large-scale energy storage. However, the high solubility of discharge species polyiodide in aqueous electrolyte is the major challenge for iodine cathode. Herein, the polyiodide doped conductive polymer cathode is proposed to suppress the dissolution of active materials in electrolyte. High reversible capacity of 160 mAh/g and remarkable cycling stability with capacity retention of 79% after 700 cycles at 1.5 A/g are achieved.