Hydrophobization Engineering of the Air–Cathode Catalyst for Improved Oxygen Diffusion towards Efficient Zinc–Air Batteries

Abstract Poor oxygen diffusion at multiphase interfaces in an air cathode suppresses the energy densities of zinc–air batteries (ZABs). Developing effective strategies to tackle the issue is of great significance for overcoming the performance bottleneck. Herein, inspired by the bionics of diving flies, a polytetrafluoroethylene layer was coated on the surfaces of Co3O4 nanosheets (NSs) grown on carbon cloth (CC) to create a hydrophobic surface to enable the formation of more three‐phase reaction interfaces and promoted oxygen diffusion, rendering the hydrophobic‐Co3O4 NSs/CC electrode a higher limiting current density (214 mA cm−2 at 0.3 V) than that (10 mA cm−2) of untreated‐Co3O4 NSs/CC electrode. Consequently, the assembled ZAB employing hydrophobic‐Co3O4 NSs/CC cathode acquired a higher power density (171 mW cm−2) than that (102 mW cm−2) utilizing untreated‐Co3O4 NSs/CC cathode, proving the enhanced interfacial reaction kinetics on air cathode benefiting from the hydrophobization engineering.