Optimized Li4Ti5O12 Nanoparticles by Solvothermal Route for Li-Ion Batteries

Li4Ti5O12 (LTO) nanoparticles were successfully synthesized by solvothermal technique using cost-effective precursors in polyol medium and post-annealed at temperatures of 400,500, and 600 degrees C. The XRD patterns of the samples were clearly indexed to the spinel shaped Li4Ti5O12 (space group, Fd-3 m). The particle size and morphology of samples were identified using field-emission SEM. The electrochemical performance of solvothermal samples revealed fairly high initial discharge/charge specific capacities in the range 230-235 and 170-190 mAh/g, at 1 C-rate, while that registered for the solid-state sample has been 160 and 150 mAh/g, respectively. Furthermore, among these samples, LTO annealed at 500 degrees C exhibited highly improved rate performances at C-rates as high as 30 and 60 C. This was attributed to the achievement of small particle sizes with high crystallinity in nano-scale dimensions and hence shorter diffusion paths combined with larger contact area at the electrode/electrolyte interface.