Sequentially Electrodeposited MnO X /Co-Fe as Bifunctional Electrocatalysts for Rechargeable Zinc-Air Batteries

Abstract

© The Author(s) 2017. Manganese oxide (MnOx) and cobalt-iron (Co-Fe) were sequentially electrodeposited onto a gas diffusion layer (GDL) as bifunctional electrocatalysts for rechargeable zinc-air batteries. The fabricated material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The sequentially deposited MnOx/Co-Fe catalysts, tested using cyclic voltammetry (CV), showed activity for both the oxygen reduction and oxygen evolution reactions (ORR and OER), with better performance than either MnOx or Co-Fe alone. The fabricated material was assembled into a zinc-air battery as the air electrode component for battery cycling tests. The zinc-air battery using MnOx/Co-Fe catalysts exhibited good discharge-recharge performance and a cycling efficiency of 59.6% at 5 mA cm −2 , which is comparable to Pt/C catalysts. In addition, the electrodeposited MnOx/Co-Fe layer showed strong adhesion to the gas diffusion layer (GDL) and was structurally stable throughout 40 h of battery cycling.