Vanadium-doped TiO2-B/Anatase Mesoporous Nanotubes with Improved Rate and Cycle Performance for Rechargeable Lithium and Sodium Batteries

Abstract TiO2-B/anatase nanotubes doped by vanadium have been synthesized through a facile one-step hydrothermal reaction. The material shows a mesoporous structure with a specific surface area of 179.1 m2 g−1. XPS data presume the presence of V3+, V4+, V5+, and Ti3+ in doped TiO2-B/anatase. As found by XRD and EIS investigations, the vanadium expands bronze titania crystal structure and enhances the conductivity of material by three orders of magnitude. When tested for lithium storage, the V-modified titania nanotubes show a specific capacity of 133 mA h g–1 after 100 charge/discharge cycles at the current density of 3000 mA g–1 with a Coulombic efficiency of around 98.9%, resulting in its good cycleability. The material still possesses a reversible capacity of 114 mA h g–1 at a very high current load of 6000 mA g–1, demonstrating superior rate characteristics for secondary lithium batteries. Furthermore, V-doped TiO2-B/anatase mesoporous nanotubes show promise performance as anode material for sodium-ion batteries, delivering about 119 mA h g–1 and 101 mA h g–1 at the current loads of 10 and 1500 mA g–1, respectively.