Localized Negatively Charged Interfaces for Seawater Electrolyte‐Based Zinc‐Air Batteries

Abstract Seawater electrolyte‐based zinc‐air batteries (S‐ZABs) are considered the promising choice for highly efficient marine power supply, owing to their high specific energy, low cost, and eco‐friendliness. However, the air‐cathode suffers from the sluggish oxygen reduction reaction (ORR) kinetics together with the severe adsorption of Cl⁻ in seawater electrolytes, which severely limits the service life and efficiency of S‐ZABs. Herein, precisely decorating axially coordinated Cl ions (Cl⁻) on Fe atomic sites (Cl‐Fe_SA/NC) to construct a local negatively charged interface to inhibit the adsorption of Cl⁻ is proposed, which exhibits a desirable ORR activity, and good stability with almost no loss in electrocatalytic performance after long‐term stability test. Moreover, the assembled battery achieves a peak power density of 208.0 mW cm⁻², which is 1.45 times higher than commercial Pt/C‐based S‐ZABs. Density functional theory calculations reveal that the axially coordinated Cl⁻ not only constructs a local negatively charged interface to inhibit the corrosion and poisoning of Fe active sites by Cl⁻, but also regulates the electronic states of Fe active sites to optimize adsorption/desorption energy of intermates, thus improving the electrocatalytic activity and stability of Cl‐Fe_SA/NC.