Preparation and electrochemical performance of Li4Ti5O12/carbon/carbon nano-tubes for lithium ion battery

A Li4Ti5O12/carbon/carbon nano-tubes (Li4Ti5O12/C/CNTs) composite was synthesized by using a solid-state method. For comparison, a Li4Ti5O12/carbon (Li4Ti5O12/C) composite and a pristine Li4Ti5O12 were also synthesized in the present study. The microstructure and morphology of the prepared samples are characterized by XRD and SEM. Electrochemical properties of the samples are evaluated by using galvanostatic discharge/charge tests and AC impedance spectroscopy. The results reveal that the Li4Ti5O12/C/CNTs composite exhibits the best rate capability and cycling stability among the samples of Li4Ti5O12, Li4Ti5O12/C and Li4Ti5O12/C/CNTs. At the charge-discharge rate of 0.5 C, 5.0 C and 10.0 C, its discharge capacities were 163 mAh/g, 148 mAh/g and 143 mAh/g, respectively. After 100 cycles at 5.0 C, it remained at 146 mAh/g. (C) 2010 Elsevier Ltd. All rights reserved.