Template-free synthesis of mesoporous spinel lithium titanate microspheres and their application in high-rate lithium ion batteries

Mesoporous spinel lithium titanate Li4Ti5O12 microspheres were prepared by template-free hydrothermal process in ethanol-water mixed solution and subsequent heat treatment. The role of ethanol helps the formation of a mesoporous structure during the hydrothermal process. A mechanism analogous to the Kirkendall effect was proposed to account for the template-free formation of these mesoporous nanostructures. As anode materials for high-rate lithium ion battery, the Li4Ti5O12 mesoporous spheres exhibited superior high-rate performance of 114 mA h g(-1) at 30C and good capacity retention of 125 mA h g(-1) after 200 cycles at 20C, which indicates promising application in high-rate lithium ion batteries.