Anatase-TiO2/CNTs nanocomposite as a superior high-rate anode material for lithium-ion batteries

Anatase-TiO2/carbon nanotubes (CNTs) with robust nanostructure is fabricated via a facile two-step synthesis by ammonia water assisted hydrolysis and subsequent calcination. The as-synthesized nanocomposite was characterized employing X-ray powder diffraction, Fourier transform infrared spectrophotometry, Raman spectrophotometry, thermal gravimetric analysis, transmission electron microscopy, high-resolution transmission electron microscopy and selected area electronic diffraction, and its electrochemical properties as an anode material for lithium-ion batteries (LIBs) were investigated by cyclic voltammetry, galvanostatic discharge/charge test and electrochemical impendence spectroscopy. The results show that the pure anatase TiO2 nanoparticles with diameters of about 10 nm are uniformly distributed on/among the CNTs conducting network. The as-synthesized nanocomposite exhibits remarkably improved performances in LIBs, especially super-high rate capability and excellent cycling stability. Specifically, a reversible capacity as high as 92 mA h g(-1) is achieved even at a current density of 10 A g(-1) (60 C). After 100 cycles at 0.1 A g(-1), it shows good capacity retention of 185 mA h g(-1) with an outstanding coulombic efficiency up to 99%. Such superior Li+ storage properties demonstrate the reinforced synergistic effects between the nano-sized TiO2 and the interweaved CNTs network, endowing the nanocomposite with great application potential in high-power LIBs. (C) 2014 Elsevier B. V. All rights reserved.