Enabling High‐Power‐Density Zn‐Air Batteries via Oxygen Trapping in Lotus‐Effect‐Inspired Hydrophobic Air Electrodes

Abstract The sluggish oxygen diffusion kinetics at the triple‐phase boundary of the air cathode significantly limit the optimal power output of Zn‐air batteries (ZABs). Inspired by the “lotus effect”, this study developed a bifunctional electrocatalyst, Co─NCNTs, featuring a lotus leaf‐like structure, and constructed a 3D hydrophobic architecture to expand the triple‐phase boundaries. Consequently, the hydrophobic Co─NCNTs electrode (contact angle >140°) demonstrated enhanced oxygen adsorption on the air cathode surface compared to the hydrophilic Co─NC electrode (contact angle <70°). The assembled ZABs incorporating the lotus‐effect‐inspired bionic Co─NCNTs achieved a remarkable power density of 341 mW cm⁻², nearly double that of the hydrophilic Co─NC‐based battery (178 mW cm⁻²), and exhibited exceptional cycling stability, operating continuously for 700 h at a current density of 10 mA cm⁻². This work highlights the efficacy of hydrophobic interface engineering in improving the reaction kinetics of air cathodes in ZABs through bionic design, offering a promising strategy for enhancing the power density of oxygen‐involved energy storage systems.