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 Co 3 O 4 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‐Co 3 O 4 NSs/CC electrode a higher limiting current density (214 mA cm −2 at 0.3 V) than that (10 mA cm −2 ) of untreated‐Co 3 O 4 NSs/CC electrode. Consequently, the assembled ZAB employing hydrophobic‐Co 3 O 4 NSs/CC cathode acquired a higher power density (171 mW cm −2 ) than that (102 mW cm −2 ) utilizing untreated‐Co 3 O 4 NSs/CC cathode, proving the enhanced interfacial reaction kinetics on air cathode benefiting from the hydrophobization engineering.