Single step solid state synthesis and characterization of Li4Ti5 xFexO12 y (0 x 0.1) as an anode for lithium ion batteries
We carried out a single step doping reduction, Li4Ti5 xFexO12 y (0 x 0.1) with Fe, by a facile solid phase method with the objective of improving the electrochemical performance of Li4Ti5O12 (LTO) Unlike the conventional method of using an Fe salt as a dopant, elemental Fe is used here as both a reducing agent and a dopant. The Fe first reacts with TiO2 to form Ti3+ and Fe3+ ions; the Fe3+ ions then incorporate into the TiO2 crystal lattice through substitution of Ti by Fe; the amount of Ti3+/Ti4+ is increased as a result of charge compensation, which further improves the conductivity of the LTO, resulting in high electrochemical performance. The investigation of the electrochemical performance of lithium ion batteries under low voltage conditions is important for assessing their safety. Because LTO can provide a higher battery voltage and a discharge capacity at a lower voltage, the electrochemical behavior of LTO in the voltage range 0 3 V was also investigated. The modified Li4Ti5 xFexO12 y exhibits a capacity of 228.7 mA h g 1 after 200 cycles, which is substantially higher than that of pure LTO (176.3 mA h g 1) In addition, the band structure and density of states (DOS) of the original and Fe doped Li4Ti5O12 were calculated by first principles calculations. The Li4Ti5 xFexO12 y (0 x 0.1) can provide a higher voltage, enabling its broad application in lithium ion batteries because of its large discharge range, good electrochemical performance, and simple synthesis process.