High-performance bifunctional electrocatalysts for zinc-air batteries using coaxial electrospun hollow N-doped carbon nanofibers decorated with NiCo and CoMn nanocrystals

Zinc-air batteries (ZABs) have garnered significant attention as ideal power sources for wearable electronic devices. However, the slow reaction kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remain a major obstacle to their widespread application. Herein, coaxial electrospinning followed by carbonization is utilized to synthesize hollow N-doped carbon nanofibers (CNFs). The inner surface of these CNFs is decorated with OER-active NiCo nanoparticles, while the outside surface is modified with ORR-active CoMn nanocrystals. The resulting NiCo@C@CoMn CNFs exhibit excellent bifunctional oxygen electrocatalytic performance, with an ORR half-wave potential of 0.82 V and an OER overpotential of 398 mV at 10 mA cm- 2. Batteries assembled with this catalyst demonstrate an open-circuit voltage of 1.44 V, a power density of 130.3 mW cm- 2, a specific capacity of 798.4 mAh g- 1, and a cycle life of 1650 h. Additionally, solid-state ZABs based on NiCo@C@CoMn CNFs show a high open-circuit voltage of 1.41 V, a power density of 91.5 mW cm- 2 and a cycle life of 30 h. This approach provides a novel strategy for synthesizing high-performance electrocatalysts with bifunctional catalytic properties.