Biomass-Derived Carbon-Coated FeCo Alloys as Highly Efficient Bifunctional Electrocatalyst for Rechargeable Zinc-Air Batteries

The development of highly effective bifunctional electrocatalysts for the oxygen reduction (ORR) and evolution reactions (OERs) is pivotal for the advancement of rechargeable zinc-air batteries (ZABs) with superior electrochemical performance. This study presents a facile strategy for the synthesis of a biomass-derived nitrogen-doped carbon-coated FeCo catalyst. By optimizing the calcination temperature, the FeCo@NC-900, synthesized at 900 degrees C, demonstrates superior ORR/OER performance, with a half-wave potential of 0.81 V for ORR and an overpotential of 349 mV to drive a current density of 10 mA cm-2 for OER. Electrochemical testing of ZABs employing FeCo@NC-900 as electrode catalysts reveals excellent performance, with a peak power density of 103.6 mW cm-2 at 160 mA cm-2 and sustains operation for over 300 h at a current density of 5 mA cm-2 with superior cycling stability. These results surpass those of the Pt/C-RuO2-based counterpart. Given its low cost and straightforward preparation, FeCo@NC-900 emerges as a highly promising catalyst for energy storage and conversion applications.