Hydrothermal synthesis of Li<inf>4</inf>Ti<inf>5</inf>O<inf>12</inf>/C nanostructured composites: Morphology and electrochemical performance

Abstract

Li4Ti5O12/C composites with low (3 wt.%) and high (33 wt.%) carbon black content as well as carbon-free Li 4Ti5O12 were prepared in two steps under identical conditions: hydrothermal reaction at 130 °C and post-calcination at 400 °C. The X-ray diffraction experiments confirmed the spinel 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. © 2012 Elsevier Ltd.