Characterization of spherical-shaped Li4Ti5O12 prepared by spray drying

This work introduces a novel solution system not slurry to synthesize nano-micron sized Li4Ti5O12 by spray drying followed by solid-state calcination at several temperatures between 650 and 800 degrees C. Well-crystallized Li4Ti5O12 with no impurity can be obtained at temperatures of 650, 700, 750 and 800 degrees C owing to the effect of nanoscale and uniform precursor powders. However, the spherical shape of the precursor powders is maintained after post-treatment at temperatures of 650 and 700 degrees C. Because of the rough and porous nano-micron sized spherical particles, the Li4Ti5O12 obtained at relatively low calcined temperatures of 650 and 700 degrees C show better rate capabilities than them of the Li4Ti5O12 obtained at higher temperatures of 750 and 800 degrees C. At the relatively low calcined temperature of 650 degrees C, the Li4Ti5O12 shows the best electrochemical performance. The initial discharge capacities are 174.8, 170.5, 167.5, 165.3, 158.2, 152.1, 130.9 and 111.9 mAh g(-1) at the 0.1C, 0.5C, 1C, 2C, 5C, 10C, 15C and 20C rates, respectively. After 100 cycles, the as-prepared Li4Ti5O12 retains 99.6%, 96.9%, 98.8%, 89.3%, 90.4% and 89.0% of its initial discharge capacities at the 1C, 2C, 5C, 10C, 15C and 20C rates, respectively. (C) 2012 Elsevier Ltd. All rights reserved.