Solid-state synthesis of Li(4)Ti(5)O(12) for high power lithium ion battery applications

Li(4)Ti(5)O(12) was synthesized by a solid-state reaction between Li(2)CO(3) and anatase TiO(2) for applications to high power lithium ion batteries. The starting materials underwent 6 h of high energy milling using ZrO(2) beads with two different sizes, 0.30 and 0.45 mm. The smaller ZrO(2) beads resulted in finer starting materials. Spray drying was also performed on the 0.30 mm beads-treated particles to enhance the screen printability of a paste containing this powder. The finer starting materials showed a pure 162 nm-sized Li(4)Ti(5)O(12) due to the decreased diffusion length for a solid-state reaction, whereas the 0.45 mm beads-treated starting materials resulted in a 242 nm-sized Li(4)Ti(5)O(12) phase containing 2 wt.% of rutile TiO(2) that had transformed from the anatase phase during heat treatment at 800 degree C for 3 h. The finer Li(4)Ti(5)O(12) showed higher charge capacity and better charge/discharge rates than the coarser particles, which highlights the importance of the primary particle size on the electrochemical properties of Li(4)Ti(5)O(12) for high power applications. The fine Li(4)Ti(5)O(12) particles had a discharge capacity of 174 mAh/g at 0.1 C and capacity retention of 80% at 10.0 C.