Boosting Bifunctional Oxygen Electrocatalysis via FeCoNiCuMn High-Entropy Alloy Encapsulated within N-Doped Carbon...

The development of efficient bifunctional oxygen electrocatalysts is crucial for the advancement of rechargeable zinc-air batteries (ZABs). Herein, we report a novel core-shell structured high-entropy alloy (HEA) catalyst (FeCoNiCuMn@NC) derived from a multimetal Prussian blue analog (PBA), which integrates FeCoNiCuMn HEA nanoparticles encapsulated within a porous nitrogen-doped carbon network. FeCoNiCuMn@NC exhibits a well-defined interconnected carbon framework with abundant mesopores and a high specific surface area. The multicomponent HEA core induces lattice distortion that modulates the electronic structure of N-doped carbon (NC) shell, optimizing the electrocatalytic activity for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Benefiting from the synergistic interplay between the HEA core and the N-doped carbon shell, the catalyst demonstrates outstanding bifunctional ORR/OER activity, with a half-wave potential of 0.842 V for ORR and an overpotential of 400 mV at 10 mA cm^-2 for OER. Moreover, the unique core-shell encapsulation structure effectively prevents nanoparticle agglomeration and protects the HEA core from corrosion in alkaline electrolyte, ensuring remarkable durability. As a demonstration of its practical potential, a ZAB incorporating the FeCoNiCuMn@NC air cathode achieves a peak power density of 135.8 mW cm^-2 together with excellent rate capability and long-term cycling stability. This work offers a rational design strategy for HEA-based bifunctional electrocatalysts toward advanced energy storage devices.