The preparation and characterization of Li4Ti5O12/carbon nano-tubes for lithium ion battery

Li4Ti5O12/carbon nano-tubes (CNTs) composite was prepared by sol-gel method while Ti(OC4H9)(4), LiCH3COO center dot 2H(2)O and the n-heptane containing CNTs were used as raw materials. The characters of Li4Ti5O12/CNTs composite were determined by XRD, SEM, and TG methods. Its electrochemical properties were measured by charge-discharge cycling and impedance tests. It was found that the prepared Li4Ti5O12/CNTs presented an excellent rate capability and capacity retention. At the charge-discharge rate of 5C and 10C, its discharge capacities were 145 and 135 mAhg(-1), respectively. After 500 cycles at 5C, the discharge capacity retained as 142 mAhg(-1). It even could be cycled at the rate of 20C. The excellent electrochemical performance of Li4Ti5O12/CNTs electrode could be attributed to the improvement of electronic conductivity by adding conducting CNTs and the nano-size of Li4Ti5O12 particles in the Li4Ti5O12/CNTs composite. (C) 2008 Published by Elsevier Ltd.