One-step solvothermal synthesis of single-crystalline TiOF ₂ nanotubes with high lithium-ion battery performance

Single-crystalline TiOF ₂ nanotubes were prepared by a one-step solvothermal method. The nanotubes are rectangular in shape with a length of 2-3 μm, width of 200-300 nm, and wall thickness of 40-60 nm. The formation of TiOF ₂ nanotubes is directly driven by the interaction between TiF ₄ 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 TiOF ₂ nanoparticles and nanorods. Compared with TiO ₂, which is the more commonly considered anode material in lithium-ion batteries, TiOF ₂ 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 TiOF ₂ nanotubes showed good Li-storage properties with high specific capacities, stable cyclabilities, and good rate capabilities. The superiority of the tube: Single-crystalline TiOF ₂ nanotubes were prepared by a simple solvothermal method (see figure) and show superior capacities for Li ⁺ storage compared with other types of TiOF ₂ nanoparticles. This high capacity makes the nanotubes potentially interesting anode materials in rechargeable lithium batteries.