Ultra-Small Fe2N/N-CNTs as Efficient Bifunctional Catalysts for Rechargeable Zn-Air Batteries

Zinc-air batteries (ZABs) have been considered as promising next-generation batteries due to their natural abundance, flat discharge voltage and high theoretical specific energy density. However, the wide application of these ZABs is seriously hindered by the high cost and poor electrochemical stability of noble electrocatalysts. In this paper, we develop a facile method to prepare ultra-small iron-based nitride and nitrogen doped carbon nanotubes (Fe2N/N-CNTs) hybrid materials as bifunctional electrocatalysts for ZABs. In the presence of CNTs with large surface areas, ultra-small Fe2N nanoparticles with the diameter of around 5 nm are successfully prepared. The oxygen reduction reaction (ORR) activity of Fe2N/N-CNTs is comparable to the Pt/C, while the oxygen evolution reaction (OER) activity is much better than the Pt/C. At last, the home-made ZABs with Fe2N/N-CNTs have significant rechargeable activities and cyclic stability.