Preparation of TiNb6O17 nanospheres as high-performance anode candidates for lithium-ion storage

This work reports the preparation of TiNb6O17 nanospheres via a facile electrostatic spraying route and their lithium storage mechanism. When selected as anode material in half-cell, TiNb6O17 nanospheres possess the high capacity, extraordinary rate performance, and outstanding cyclability. The results exhibit that TiNb6O17 nano-spheres deliver an initial discharge capacity of 245 mAh g(-1) with a high Coulombic efficiency of 86.37% at 0.5 C, and even after 150 cycles, a reversible capacity of 159.1 mAh g(-1) is kept with Coulombic efficiency close to 100%. The outstanding electrochemical properties of TiNb6O17 nanospheres can be ascribed to their unique morphologies. In addition, the electrochemical kinetics of TiNb6O17 nanospheres is investigated by cyclic voltammetry. The results indicate that their electrochemical behavior is composed of two parts, lithium ion diffusion and pseudo-capacitive characteristic. Furthermore, lithium ion storage mechanism of TiNb6O17 nanospheres is studied by in situ X-ray diffraction instrument, revealing superior electrochemical reversibility and structure stability. Based on the aforementioned measurements, it can be concluded that TiNb6O17 nanospheres have the potential for practical use in lithium ion batteries.