Synthesis of Nanocrystalline Fe₂O₃ for Lithium Secondary Battery Cathode

Iron based oxides were synthesized by precipitation route from a ferric nitrate aqueous solution at low temperature followed by heat treatment of the precipitate. The samples thus obtained were characterized by X-ray powder diffraction, transmission electron microscopy, surface area measurement, and electrochemical investigation in a LiClO4-propylene carbonate solution. Nanocirystalline α-Fe2O3 powders, which were obtained by heat treatment at 200°C, demonstrated high reversible capacity of >200 mAh g−1 and good cyclability as a positive electrode of Li batteries. It was likely that the discharge-recharge of the nanocrystalline α-Fe2O3 was due to a topochemical reaction accompanied with lithium insertion/extraction.