Boosting Zinc–Iodine Battery Performance via Polyaniline‐Coated N,O‐Codoped Porous Carbon With Enhanced Conductivity and Polyiodide Adsorption

Aqueous zinc–iodine batteries (AZIBs) have emerged as promising candidates for grid‐scale energy storage due to their low cost, high safety, notable specific capacity, and environmental benignity. However, their practical application is hindered by several challenges associated with the iodine cathode, including insulating property of iodine and shuttle effect of polyiodide intermediates, which collectively lead to poor electrochemical performance. Herein, we report a rational strategy for synthesizing a polyaniline‐coated, nitrogen‐ and oxygen‐codoped porous carbon composite (denoted as PANI/NOCN) as a high‐performance cathode host for AZIBs. The as‐prepared PANI/NOCN composite features a mechanically robust, hierarchically porous nanostructure with a high specific surface area. Furthermore, the conductive polyaniline coating establishes efficient charge‐transfer pathways and provides additional chemisorption sites for polyiodides. This architecture effectively accommodates iodine species and suppresses the polyiodide shuttle effect. The PANI/NOCN@I ₂ cathode delivers a high reversible discharge capacity of 115  mAh  g ⁻¹ at 10 A  g ⁻¹ and retains 90  mAh g ⁻¹ after 2000 cycles, demonstrating excellent rate capability and cycling stability. This work demonstrates that the synergistic combination of heteroatom doping and conductive polymer coating is an effective strategy for designing advanced cathode hosts, offering valuable insights for the development of high‐performance AZIBs.