Zincophilic Molecular Reconstructs the Electrolyte/Electrode Interface for Stable Aqueous Zn Batteries

Aqueous zinc‐ion batteries are attractive for grid‐scale energy storage owing to their intrinsic safety and low cost, yet their practical deployment is hindered by uncontrolled zinc dendrite growth and parasitic interfacial reactions. Here, we report a multifunctional electrolyte‐engineering strategy using a low‐concentration organic additive, iodoacetamide (IAM), to regulate both interfacial chemistry and water activity in ZnSO 4 electrolytes. The carbonyl group of iodoacetamide exhibits strong affinity for Zn 2+ , enabling preferential adsorption on the zinc surface, while the iodine moiety forms a hydrophobic interfacial layer that suppresses direct water contact. Simultaneously, the amino group disrupts the hydrogen‐bonding network of water, reducing the activity of free water in the electrolyte. The synergistic action of these functional groups promotes the formation of a stable and robust solid electrolyte interphase, effectively mitigating zinc dendrite growth, hydrogen evolution, and anode corrosion. As a result, zinc anodes exhibit exceptional cycling stability exceeding 5000 h at 1 mA cm −2 with an areal capacity of 1 mAh cm −2 . When paired with MnO 2 cathodes, the modified electrolyte delivers enhanced capacity retention and prolonged full‐cell lifespan. This work highlights the potential of rationally designed multifunctional organic additives to address interfacial instability in aqueous zinc‐ion batteries, offering a generalizable pathway toward durable and high‐performance aqueous energy‐storage systems.