Oxidative ammonolysis modified lignin-derived nitrogen-doped carbon-supported Co/Fe composites as bifunctional electrocatalyst for Zn-air batteries

Zn-air battery (ZAB) has garnered significant attention owing to its environmental friendliness and safety attributes. A critical challenge in advancing ZAB technology lies in the development of high-performance and cost-effective electrocatalysts for oxygen redox reactions (OER and ORR). Herein, we report Co/Fe carbon-supported composites as efficient bifunctional catalysts encapsulated in oxidative ammonolysis modified lignin-derived N-doped biochar (CoFe-CoxN@NOALC). It exhibited exceptional electrochemical performance in aqueous ZAB owing to their uniform dispersed and small particle size, with a peak power density of 154 mW/cm2 and a specific capacity of 770 mAh/g. Most notably, it exhibited a long cycle stability, surpassing 1500 h at a current density of 10 mA/cm2, with a mere 11.4% decrease in the charge-discharge efficiency of the battery. This study proposes a viable strategy for enhancing the performance and reducing the cost of Zn-air batteries through the utilization of biomass-derived materials.