Hydrothermal synthesis of Li4Ti5O12/C nanostructured composites: Morphology and electrochemical performance

Li4Ti5O12/C composites with low (3 wt.%) and high (33 wt.%) carbon black content as well as carbon-free Li4Ti5O12 were prepared in two steps under identical conditions: hydrothermal reaction at 130 degrees C and post-calcination at 400 degrees C. The X-ray diffraction experiments confirmed the spinet structure of Li4Ti5O12 in all samples. The carbon content altered significantly the morphology of obtained micro/nanoparticles. The Li4Ti5O12/C composite with the high carbon content showed the highest electrical conductivity (2.0 S cm(-1)), and displayed also extraordinary electrochemical performance: the cyclovoltammograms consisted of well defined reversible redox peaks at a scan rate as high as 10 mV s(-1), while, by galvanostatic cycling, the coulombic capacity of 150 mAh g(-1) was evidenced at a discharging rate of 10 C. (c) 2012 Elsevier Ltd. All rights reserved.