Electrochemical Performance of Anatase Nanotubes Converted from Protonated Titanate Hydrate Nanotubes

Titanium oxides with one-dimensional nanostructure are of significant interest for the electrochemical lithium insertion and extraction because of their large specific surface area and numerous surface defects. Nanotubes with 10-15 nm outer diameters and 200~400 nm long were prepared by a reaction between rutile and caustic soda under hydrothermal conditions. These nanotubes are protonated titanate and can be converted into the anatase nanotubes after calcination at 500 deg C in argon atmosphere. The anatase nanotubes exhibited a high reversible discharge capacity, excellent high-rate discharge capability, and good cycle stability under the large current density.