Mechanochemical-hydrothermal synthesis of layered lithium titanate hydrate nanotubes at room temperature and their conversion to Li4Ti5O12.

Mechanochemical-hydrothermal synthesis is a low-cost and efficient method to prepare functional particles, due to the local high-pressure and high-temperature reaction fields generated during the process. Here, mechanochemical-hydrothermal synthesis of layered lithium titanate hydrate, Li 1.81 H 0.19 Ti 2 O 5 · x H 2 O (LHTO), using a planetary ball mill is demonstrated. By planetary ball milling of LiOH and TiO 2 with water at room temperature, LHTO nanotubes with lengths over 300 nm were synthesized. The synthesized LHTO nanotubes were transformed to Li 4 Ti 5 O 12 (LTO), which is a common anode material for Li-ion batteries, via thermal treatment while maintaining the nanotube morphology. The anode properties of the thermally prepared LTO nanotubes exhibited a first discharge capacity of 160 mAh/g at a rate of 0.1 C, even though residual TiO 2 and contamination from ZrO 2 milling balls were observed as product impurities. The reduction of impurities in the product after mechanochemical-hydrothermal synthesis is important to improve material performances. [ABSTRACT FROM AUTHOR]