Conductivity optimization via intertwined CNTs between TiNb2O7@C microspheres for a superior performance Li-ion battery anode.

Abstract Titanium niobate (TiNb2O7, TNO) possesses attractive discharge voltage and reversibility, which is considered to be an ideal anode material of lithium ion battery (LIB). However, its rate capability is strictly limited by their poor conductivity. To improve this issue faced by traditional TNO electrodes, a hierarchical conductive optimization strategy has been proposed and fabricated by a facile spray drying approach. For the construction, TiNb2O7@ultrathin carbon layer (TNO@C) is entangled into carbon nanotubes network to synthesize a highly conductive porous TNO@C/CNTs microsphere. This ultrathin carbon layer and evenly intertwined carbon nanotubes can ensure the superior charge transfer pathway, facilitating the transportation of electrons and Li ions. Additionally, CNTs can provide robust mechanical strength framework, beneficial to the structural stability of composite microspheres. As expected, the TNO@C/CNTs exhibits elevated conductivity and cyclic durability with charge capacities of 343.3 mAh·g-1 at 0.25 C after 300 cycles and 274.9 mAh·g-1 at 10 C after 1000 cycles. This study intends to explore the effect of the attached carbon materials on the TNO-based electrode conductivity and LIBs performances.