Iron‐Regulated D‐Band Center in Fe‐V2O5‐n/rGO Heterostructures Enables Ultralong‐Cycling Zinc‐Iodine Batteries via Optimal Iodine Adsorption‐Desorption Dynamics

Abstract

The intrinsically low electrical conductivity of elemental iodine and its slow redox kinetics represent two significant obstacles that hinder the commercialization of aqueous zinc‐iodine batteries. These challenges can be addressed by modulating the adsorption‐desorption equilibrium of iodide ions in the active material. This study presented a synergistic strategy of “Electronic Modulation” and “Phase Transition Engineering” to optimize the catalytic adsorption‐desorption dynamics. A dual‐designed Fe ions doped VO2‐x heterostructure anchored on reduced graphene oxide (Fe‐VO2‐x/rGO) is demonstrated to synchronously adjust iodine adsorption and boost redox kinetics. The Fe‐induced electronic structure modulation elevated the d‐band center of vanadium, creating catalytic sites to promote the desorption of iodide ions and facilitate their diffusion. Concurrently, the phase transition from VO2‐x to V2O5‐n within the heterostructure establishes a 3D conductive network, synergizing with rGO to ensure rapid ion/electron transport. This “adsorption‐catalysis‐transport” collaborative mechanism enabled the Fe‐VO2‐x/rGO cathode to achieve an ultrahigh capacity retention of 81.48% after 60,000 cycles at 20 A g−1, surpassing state‐of‐the‐art zinc‐iodine systems. The work provides a paradigm for manipulating interfacial dynamics through electronic and crystallographic dual regulation in conversion‐type batteries.