Co-N-Doped Directional Multichannel PAN/CA-Based Electrospun Carbon Nanofibers as High-Efficiency Bifunctional Oxygen Electrocatalysts for Zn–Air Batteries

A reasonable design of the pore structure of carbon nanofiber-based electrocatalysts can effectively accelerate the slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this study, we report an electrospinning method by adding supramolecular coordination polymers to selected polyacrylonitrile (PAN) and cellulose acetate (CA) spinning systems. Benefiting from the difference in the thermal decomposition temperature of each component during the pyrolysis process, CA was applied as a sacrificial template to prepare a high-efficiency ORR/OER bifunctional electrocatalyst (Co-N@PCNFs-0.2) with directional hollow channels and a hierarchical pore structure. This unique multichannel carbon nanofiber morphology and hierarchical pore structure led to abundant active sites while also boosting the electron transfer rates. Notably, applying Co-N@PCNFs-0.2 as an air electrode to Zn–air batteries results in a large specific discharge capacity of 884 W h kgZn–1 and a maximum power density of 151 mW cm–2.