Coupling CoNi‐LDH and Fe2N Nanoparticles on N‐Doped Biomass‐Derived Carbon as Oxygen Electrocatalyst for Rechargeable Zn‐Air Batteries

The engineering of structure and composition is crucial and challenging for modulating electrocatalytic activity. Herein, a bifunctional electrocatalyst, CoNi@Fe2N/C, is designed and prepared by coupling CoNi-layered double hydroxides (CoNi-LDH) nanosheets and Fe2N nanoparticles on 3D N-doped biomass-derived carbon through pyrolysis and electric field induction. CoNi@Fe2N/C delivers remarkable bifunctional electrocatalytic activity with a narrow overpotential gap (ΔE) of only 0.63 V for ORR and OER, surpassing commercial Pt/C+RuO2. Additionally, the aqueous rechargeable zinc-air batteries (RZABs) assembled with CoNi@Fe2N/C as a catalyst on the air electrode show a high peak power density (177.4 mW cm-2) and excellent durability (over 360 h). The high stability of 3D biomass-derived carbon assures the high durability of catalysts. Assistance of electric field induction ensures the uniform dispersion of CoNi-LDH nanosheets on 3D N-doped biomass-derived carbon. The interaction at the interface between two components appropriately modulates the electronic structure of hybrids via charge transfer to promote reaction kinetics. This work will provide a practical avenue to create ORR/ OER bifunctional biomass-derived catalytically active carbon hybrid catalysts for efficient RZABs.