Electrochemical sodium storage of TiO2(B) nanotubes for sodium ion batteries

Exploring new anode materials is important for developing sodium ion batteries. In this work, TiO2(B) nanotubes are prepared by hydrothermal reaction in concentrated NaOH solution and subsequent calcination at 300 degrees C in air, and investigated for the first time as anodes for sodium ion batteries. It is demonstrated that TiO2(B) nanotubes are several hundred nanometers in length with an outer diameter of about 10-15 nm. Moreover, the interference fringe spacings of the nanotubes are derived from the TEM image, being about 0.56 and 0.34 nm, which are consistent with the interplanar distances of the (001) and (110) planes in the TiO2(B) phase, respectively. As anticipated, the interlayer spacing of the (001) plane in the TiO2(B) nanotubes is large enough to accommodate sodium ions. Meanwhile, the tubular morphology can ensure the good high rate capability and cycle stability. Therefore, TiO2(B) nanotubes present feasible electrochemical sodium storage, offering possibilities to develop new anode materials for sodium ion batteries.