Enhanced High-Rate Performance of Li4Ti5O12 Nanoparticles for Rechargeable Li-Ion Batteries

Li4Ti5O12 was successfully synthesized by solvothermal techniques using cost-effective precursors in polyol medium. The x-ray diffraction (XRD) pattern of the sample (LTO-500) was clearly indexed to the spinel shaped Li4Ti5O12 and in order to accurately determine the lattice parameters, synchrotron powder XRD pattern was fitted by the whole-pattern profile matching method using the model space group, Fd (3) over barm. The particle size, morphology, and crystallinity of LTO-500 were identified using field-emission scanning electron microscopy and transmission electron microscopy. The electrochemical performance of the sample revealed fairly high initial discharge/charge specific capacities of 230 and 179 mAh/g, respectively, and exhibited highly improved rate performances at C-rates as high as 30 and 60 C, when compared to Li4Ti5O12 by the solid-state reaction method. This was attributed to the achievement of small particle sizes in nanoscale dimensions, a reasonably narrow particle size distribution and, hence, shorter diffusion paths combined with larger contact area at the electrode/electrolyte interface. (C) 2011 The Electrochemical Society. [DOI:10.1149/1.3527983] All rights reserved.