Sn-doped TiO ₂ nanotubes as superior anode materials for sodium ion batteries

Sn-doped TiO2 nanotubes were employed as anodes for sodium ion batteries. The electrodes exhibit a high maximum charge capacity of 257 mA h g(-1) after 50 cycles at a current density of 50 mA g(-1) with good rate capability and especially excellent cycling stability, mainly due to the increase of electrical conductivity by Sn doping.