Engineered Atom-Particle Coupling in Dice-Like Hollow Carbon Cages Accelerates Oxygen Electrocatalysis for Efficient Zinc-Air Batteries.

Sluggish oxygen electrocatalytic kinetics and diffusion limitations remain key barriers to high-performance zinc-air batteries (ZABs). Herein, we report a dice-like Co/N codoped hollow carbon cage catalyst (Co/N-HCC) featuring efficient atom-particle coupled Co single atoms and nanoparticles (CoSA&CoNP) confined within a hierarchically porous framework via a self-templated surface-confinement strategy. Calculations and in situ spectroelectrochemical experiments suggest that the atom-particle electronic coupling triggers substantial interfacial charge redistribution and tunes the d-band center of Co-N4 moieties, thereby regulating oxygenated intermediate adsorption and accelerating interfacial electron transfer. Remarkably, the tailored Co/N-HCC achieved superior bifunctional electrocatalytic activity with a low potential gap of 0.63 V in alkaline media. Furthermore, the Co/N-HCC-based ZAB delivers a high peak power density of 269.1 mW cm-2, a specific capacity of 813.6 mAh g-1, and robust cycling durability. This work elucidates a mechanistic paradigm for integrating atom-particle electronic coupling with hierarchical porosity toward advanced oxygen electrocatalysts.