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 °C. Well-crystallized Li4Ti5O12 with no impurity can be obtained at temperatures of 650, 700, 750 and 800  °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 °C. Because of the rough and porous nano-micron sized spherical particles, the Li4Ti5O12 obtained at relatively low calcined temperatures of 650 and 700 °C show better rate capabilities than them of the Li4Ti5O12 obtained at higher temperatures of 750 and 800 °C. At the relatively low calcined temperature of 650 °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.

► We propose a novel aqueous mixing technique to synthesize nano-micron Li4Ti5O12. ► The as-prepared material can be obtained at relatively low calcined temperature. ► The Li4Ti5O12 is well-crystallized, rough and porous nano-micron spherical particles. ► The obtained Li4Ti5O12 shows excellent rate capability and cycle ability. ► The excellent electrochemical performance may make it attractive for large applications.