Porous Fe-N-C Catalysts for Rechargeable Zinc-Air Batteries from an Iron-Imidazolate Coordination Polymer

Zn-air batteries are superior energy storage devices to Li-ion, possessing larger storage capacities with the benefits of high safety and economic viability. The large-scale use of this technology requires development of cheap and efficient bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes. Herein, a highly active bifunctional porous Fe-N-C catalyst was synthesized from a low-cost iron-imidazolate framework template. The optimized catalyst exhibits high performances for both ORR and OER processes in alkali media, with oxygen electrode activities which outperform benchmark platinum-based catalysts. Rechargeable Zn-air batteries were constructed and exhibited low overpotentials, and high stability, showing the prospect of these nonprecious metal bifunctional catalysts in metal-air batteries.