Hydrothermal synthesis of Li4Ti5O12-TiO2 composites and Li4Ti5O12 and their applications in lithium-ion batteries

Through a facile hydrothermal way, Li4Ti5O12-rutile-anatase TiO2 ternary phase composites have been successfully prepared by different Li:Ti molar ratios of 4:5 and 3.5:5 with different heat treatment temperatures of 450 and 600 degrees C. XRD, SEM and TEM were performed for physical characterizations and the results prove the existence of three components in the composites with similar morphology of nanosheets and nanoparticles. The electrochemical measurements of charge and discharge through a galvanostatic method, CV and EIS were also applied to evaluate their electrochemical performances. The discharge capacities of the first cycle of the synthesized composites can reach to -174 mAh g(-1) and approach the theoretical capacity of Li4Ti5O12, which could be attributed to the TiO2 phase introduced into the composites. The results of cyclic and rate measurements suggest that both capacities and rate performances have been enhanced by the presence of the TiO2 phase.