One-Step Solvothermal Synthesis of Single-Crystalline TiOF2 Nanotubes with High Lithium-Ion Battery Performance

Single-crystalline TiOF2 nanotubes were prepared by a one-step solvothermal method. The nanotubes are rectangular in shape with a length of 23 mu m, width of 200300 nm, and wall thickness of 4060 nm. The formation of TiOF2 nanotubes is directly driven by the interaction between TiF4 and oleic acid in octadecane to form the 1D nanorods, and this is followed by a mass diffusion process to form the hollow structures. The synthesis approach can be extended to grow TiOF2 nanoparticles and nanorods. Compared with TiO2, which is the more commonly considered anode material in lithium-ion batteries, TiOF2 has the advantages of a lower Li-intercalation voltage (e.g., to help increase the total voltage of the battery cell) and higher specific capacities. The TiOF2 nanotubes showed good Li-storage properties with high specific capacities, stable cyclabilities, and good rate capabilities.