Bioinspired Hydrophobicity Coupled with Single Fe‐N4 Sites Promotes Oxygen Diffusion for Efficient Zinc‐Air Batteries

Abstract The poor oxygen diffusion and sluggish oxygen reduction reaction (ORR) kinetics at multiphase interfaces in the cathode suppress the practical application of zinc‐air batteries. Developing effective strategies to tackle the issue is of great significance for overcoming the performance bottleneck but remains challenging. Here, a multiscale hydrophobic surface is designed on the iron single‐atom catalyst via a gas‐phase fluorination‐assisted method inspired by the structure of gas‐trapping mastoids on lotus leaves. The hydrophobic Fe‐FNC attains a higher peak power density of up to 226 mW cm−2, a long durability of up close to 140 h, and better cyclic durability of up to 300 cycles compared to the corresponding Pt/C‐based Zn‐air battery. Experiments and theoretical calculations indicate that the formed more triple‐phase interfaces and exposed isolated Fe‐N4 sites are proposed as the governing factors in boosting electrocatalytic ORR activity and remarkable cycling durability for Zn‐air batteries.