α-Fe2O3 Urchins Synthesized by a Facile Hydrothermal Route as an Anode for an Fe-Air Battery

High-performance anode materials for Fe-air batteries were synthesized using alpha-Fe2O3 microparticles with a high porosity and a large actual surface area via a hydrothermal method. Fe2O3/AB composite electrodes were fabricated by mixing the synthesized alpha-Fe2O3 microparticles with acetylene black (AB) carbon and subjected to electrochemical measurements. The alpha-Fe2O3/AB electrode cycleability of the synthesized alpha-Fe2O3 microparticles with two structures, namely porous sphere-like (urchin) and porous plate-like, was better than that of commercially available Fe2O3. The morphological characteristics and porosity of Fe2O3 influenced the electrochemical properties of the Fe2O3/AB composite electrodes, viz. the capacity provided by urchin-shaped structures was larger than that given by porous plates. The high porosity of alpha-Fe2O3 particles caused a large internal resistance and resulted in a decreased capacity of electrodes. Thus, urchin-shaped alpha-Fe2O3 microparticles could be used as an active electrode material for Fe-air battery anodes.