Scalable Electrospinning-Pyrolysis Fabrication of MOF-Derived Beaded Co/Co-Nx-C Nanofibers for High-Power and Long-Life Zn-Air Batteries

Abstract

ABSTRACT The rational design of bifunctional electrocatalysts with abundant active sites and efficient charge/mass transport is crucial for Zn‐air batteries. Here, we report a scalable electrospinning strategy to fabricate Co/N‐doped carbon nanofibers (CNFs) with a beaded architecture derived from ZIF‐67@PAN precursors. By precisely tuning the ZIF‐67 loading, the intercluster spacing along the fibers can be controlled, yielding well‐dispersed Co nanoparticles and Co‐N x moieties after pyrolysis. Critically, vertically stacked nanofibrous membranes enable scalable manufacturing. The optimized Co/Co‐N x ‐C@CNF‐1.5 exhibits superior bifunctional activity (Δ E = 0.815 V), benefiting from balanced active‐site density, rapid electron transport, and hierarchical porosity. Density functional theory calculations further reveal the microscopic origin that an appropriate spacing enables moderate electronic coupling between adjacent Co‐based active sites, thereby optimizing the adsorption energetics of oxygen intermediates and facilitating ORR/OER kinetics. As an air cathode, the liquid Zn‐air battery delivers a peak power density of 406.5 mW cm −2 , an energy density of 976 Wh kg −1 , and a long cycling stability of ∼2143 h. The quasi‐solid‐state device also shows high power output, stable operation, and excellent flexibility. This work demonstrates a general electrospinning‐pyrolysis approach to engineer MOF‐derived self‐supporting electrodes, bridging high‐performance electrocatalysis with practical energy storage applications.