Hierarchical tubular structures constructed from rutile TiO2 nanorods with superior sodium storage properties

Hierarchical tubular structures constructed from rutile TiO2 nanorods are fabricated, using MnO2 nanorods as sacrificial templates. The resultant rutile TiO2 hierarchical nanotubes show unique structural features (hierarchical, hollow) and a large surface area (180 m(2) g(-1)), which substantially improve their electrochemical performance. This type of hierarchical structures with high porosity produced by neighboring building blocks, are desirable for the development of sodium ion batteries, because the large amounts of pores can enhance the contact areas between electrode and electrolyte, and faciliate the ion diffusion during the charge/discharge process. As an anode material for sodium ion batteries, these hierarchical nanotubes deliver a high reversible capacity of 221 mA h g(-1) at 0.3 C (100 mA g(-1)), superior rate capability with a stable capacity of 71 mA h g(-1) at 15C, and good long-term cycling stability with a capacity of 79 mA h g(-1) after 1000 cycles at 3 C. The superior sodium storage performances make this rutile TiO2 hierarchical nanotube a promising anode metarial for sodium ion batteries. (C) 2016 Elsevier Ltd. All rights reserved.