Nitrogen and oxygen co-doped Fe-NX catalysts with enhanced bifunctional electrocatalytic properties for zinc-air battery applications

As a clean and sustainable energy storage technology, zinc–air batteries (ZABs) offer significant potential for future applications. However, the development of efficient, stable, and cost-effective non-precious metal catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for the widespread adoption of ZABs. In this study, Fe–NX is anchored onto nitrogen and oxygen co-doped carbon nanofibers (N,O-CNF) through a straightforward electrospinning technique, with the N and O species content further optimized via HCl etching and NH3 activation to enhance catalytic performance. In a 0.1 M KOH solution, the resulting Fe–NX@N,O-CNF-act catalyst displays superior ORR activity compared to Pt/C and OER performance comparable to that of RuO2. Additionally, it demonstrates excellent methanol tolerance and long-term stability. The assembled battery exhibits a peak power density significantly higher than that of Pt/C (113.63 mW cm−2vs. 86.26 mW cm−2), along with improved cycling stability and battery round-trip efficiency (453 cycles, 50.2%) compared to Pt/C + RuO2 (427 cycles, 44.2%). These results highlight its promising potential for applications in energy storage and conversion.