Solid-state synthesis of Li₄Ti₅O₁₂ whiskers from TiO₂-B

In this work, Li₄Ti₅O₁₂ (LTO) was synthesized from the precursors of TiO₂-B and anatase whiskers, respectively. The synthesized LTO whiskers from TiO₂-B whiskers via a solid state reaction at 650 °C have a high degree of crystallinity with an average diameter of 300 nm. However, when anatase whiskers were used as the precursor, only particle morphology LTO was produced at 750 °C. The further analysis of the precursors, the intermediate products and the final products reveal that the crystal structure of the anatase hinders the diffusion of lithium, leading to a typical reaction-diffusion process. Under this condition, only particle morphology LTO can be produced. However, the crystal structure of the TiO₂-B is easy for lithium diffusion and the process is performed in two separated steps (i.e., diffusion and reaction), which makes it possible to decrease the solid-state reaction temperature down to 650°C and then maintain the morphologies of whiskers.