Electrochemical properties of Fe2O3/AB based composite electrodes in alkaline solution

Abstract

To find a suitable material for Fe-air battery anode, Fe2O3 nanoparticles (nm) and microparticles (µm) were used as active materials and Acetylene Black carbon (AB) as additive to prepare Fe2O3/AB composites. The effect of grain size of iron oxide particles and additives on the electrochemical behavior of Fe2O3/AB composite electrodes in alkaline solution have been investigated using cyclic voltammetry (CV), galvanostatic cycling and electrochemical impedance spectroscopy (EIS) measurements. Iron oxide nanoparticles provided better cyclability than iron oxide microparticles. Impedance of electrode increased during cycling but the nm-Fe2O3/AB electrode gave smaller resistance than µm-Fe2O3/AB one. The additives showed strongly effects on the electrochemical behaviors of iron oxide electrodes. The AB additive enhanced the electric conductivity of Fe2O3/AB electrode and thus increased the redox reaction rate of iron oxide while K2S interacted and broke down the passive layer leading to improved cyclability and giving higher capacity for Fe2O3/AB electrodes.