Spherical Li4Ti5O12 synthesized by spray drying from a different kind of solution

Abstract: 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 16h in air, a pure LTO phase with a lithium-excess composition is obtained, which shows the best properties. Between 1.0 and 2.5V (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. [Copyright &y& Elsevier]