Preparation of layer structured titanate CsxTi2−xFexO4 (x=0.70) and application as cathode material in rechargeable lithium battery

The layer structured titanate CsxTi2−xFexO4 (x=0.70) with the lepidocrocite (γ-FeOOH) structure has been prepared in a solid state reaction using Cs2CO3, anatase type TiO2 and α-Fe2O3 at 800 °C. Cs+ in the interlayer space was ion exchanged with hydrated Li+ in a LiNO3 solution. The interlayer water was removed by heating at 180 °C in a vacuum. The resulting layer structured titanate Li0.60H0.04Cs0.06Ti1.30Fe0.70O4 was evaluated for use as the cathode in a rechargeable lithium battery. The theoretical capacity of the titanate is 106 mA h/g for the Fe3+/Fe2+ redox couple. The cathode exhibited discharge and charge capacities of 110 and 92 mA h/g for the first cycle in the voltage range of 1.5–4.2 V. The amounts of lithium intercalated and deintercalated in the titanate correspond to 0.73 and 0.61 of the formula unit.