Dual‐Role Zn Engineering Enables Electron Redistribution and Hierarchical Porosity in Co–N 4 Carbon Nanofibers for Efficient Zinc–Air Batteries

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ABSTRACT Developing bifunctional oxygen electrocatalysts with both high intrinsic activity and efficient mass transport remains a key challenge for rechargeable zinc–air batteries (ZABs). Herein, a dual‐role Zn engineering strategy is developed to simultaneously regulate the electronic structure and construct hierarchical porosity in Co–N 4 carbon nanofibers (Zn/Co–N@CNF). During the electrospinning–pyrolysis process, Zn acts as an electronic regulator that modulates the electronic environment of neighboring Co–N 4 sites, inducing electron redistribution and a downward shift of the Co d‐band center to −3.43 eV, thereby optimizing the adsorption energetics of oxygen intermediates. Meanwhile, Zn evaporation serves as a dynamic porogen that promotes the generation of highly dispersed Co sites and induces the formation of hierarchical pores, facilitating mass transport and maximizing active‐site accessibility. First‐principles calculations reveal that the Zn–N 4 /Co–N 4 sites enable optimized oxygen‐intermediate adsorption, leading to ultralow theoretical ORR/OER overpotentials of 0.37/0.43 V. Benefiting from this structural–electronic synergy, Zn/Co–N@CNF exhibits excellent bifunctional oxygen electrocatalytic performance with a low ΔE of 755 mV. When employed as an air cathode, the assembled ZAB delivers a high peak power density of 303 mW cm − 2 and remarkable cycling stability exceeding 1150 h without an additional carbon diffusion layer. This work establishes a dual‐role metal engineering strategy that integrates electronic modulation with hierarchical porosity for constructing high‐performance air electrodes for next‐generation zinc–air batteries.

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