Thermal Engineering of NiCo-Codoped Carbon Nanofibers toward Enhanced Oxygen Electrocatalysis for Zn–Air Batteries

Electrospinning is an efficient and facile method to prepare carbon nanofibers (CFs) embedded with a NiCo alloy as efficient oxygen electrocatalysts for Zn–air batteries. The subsequent pyrolysis of electrospun-woven is significant to the crystallization degree of CFs and NiCo alloy. Herein, the effect of the crystallization degree of the alloy and carbon on the oxygen electrocatalytic activity is explored through controlled thermal engineering (the annealing temperature). As the temperature increases, the degree of crystallization and agglomeration of nanoparticles increases simultaneously, accompanied by the increase of the graphitization degree of CFs. Among all the samples, NiCo/CF-800 exhibits the best oxygen bifunctional catalytic activity (ΔE = 0.73 V). A Zn–air battery based on the NiCo/CF-800 catalyst exhibits a high peak power density (168.6 mW cm⁻²), high specific capacity (802.6 mA h g_Zn⁻¹), and excellent charge/discharge cycling stability. This work provides new insight into catalysts through thermal engineering, promoting the practical application of electrospinning as a large-scale production method.