FeCo/N-co-doped 3D carbon nanofibers as efficient bifunctional oxygen electrocatalyst for Zn-air batteries.

Flexible zinc-air batteries (ZABs) are expected to become a promising candidate in energy storage equipment for wearable electronic devices. However, the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have impeded the development of ZABs. Herein, an FeCo- and N-codoped bifunctional electrocatalyst (FeCoNCF) is fabricated by simple one-pot and pyrolysis strategies. Concretely, the bacterial cellulose (BC) and Prussian blue analogue (PBA) derived transition metal and nitrogen doped carbon (M-N-C) composites provide ORR and OER active sites. FeCoNCF exhibits outstanding ORR and OER activities. It displays a favorable high half-wave potential (0.81 V) and a low overpotential at 10 mA cm (341 mV), which are on a par with commercial Pt/C and RuO, and shows outstanding stability. The sandwich-type flexible zinc-air battery containing FeCoNCF shows a favorable power density (49.29 mW cm) and superior cycling stability.