Synthesis of TiNb6O17/C composite with enhanced rate capability for lithium ion batteries

TiNb6O17/C composites were obtained via a facile solid-state reaction with TiO2, Nb2O5 and glucose as the starting materials. The lattice structure and morphology of the composite were investigated by X-ray diffraction, scanning electronic microscopy and transmission electron microscopy. The electrochemical properties were characterized by rate charge/discharge measurements and cyclic voltammetry. Electrochemical measurements demonstrate that the TiNb6O17/C composite exhibits electrochemical properties superior to those of pure TiNb6O17, especially at high current rates. The initial discharge capacities of TiNb6O17/C are 239, 225.1 and 199.8 mAh g−1 at 1, 5 and 10 C, respectively. Even after 500 cycles at 10 C, the capacity still remains 165.1 mAh g−1, while the capacity of TiNb6O17 is only 74.8 mAh g−1. The excellent electrochemical performance of TiNb6O17/C is attributed to the improvement of the electrical conductivity resulting from carbon coating.