Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1615503 | Journal of Alloys and Compounds | 2012 | 7 Pages |
High energy density Li4Ti5O12 powders comprising of spherical nanocrystalline are synthesized by spray drying followed by solid-state calcination. The influences of Li/Ti atomic ratios (0.784, 0.800, 0.816, and 0.832) on the performance of Li4Ti5O12 are investigated by means of Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscope (TEM), Galvanostatic cell cycling, as well as Ac impedance spectroscopy. The results indicate that, when the spray-drying precursors at the Li/Ti molar ratio of 0.816 are calcined at 700 °C for 16 h in air, a pure LTO phase with a lithium-excess composition is obtained, which shows the best properties. Between 1.0 and 2.5 V (vs. Li/Li+), the initial discharge capacities of the powder are 174, 168, 163, 153, and 136 mAhg−1 at a constant current density of 0.1, 0.5, 1, 2, and 5 C, respectively. After 100 cycles, the discharge capacities of the LTO powders remain 97, 95, and 99% of initial discharge capacities at current densities of 1, 2, and 5 C, respectively.
► The precursor powders comprise hollow particles. ► H2O2 acts as coordination agent that reacts with the Ti to form a large anion. ► Li4Ti5O12 powders can be synthesized at a low temperature of 700 °C. ► The spherical Li4Ti5O12 powders show excellent electrochemical performance. ► We hope our work will be helpful for other research groups.