General synthesis of carbon-coated nanostructure Li₄Ti₅O₁₂ as a high rate electrode material for Li-ion intercalation

A simple approach is proposed to synthesize nanostructured Li₄Ti₅O₁₂ spinel materials with different morphologies (nanorods, hollow spheres and nanoparticles), in which the TiO₂ precursor is first coated with a conductive carbon layer by the chemical vapour decomposition (CVD) method, followed by a solid-state reaction with lithium salt. The Li₄Ti₅O₁₂ obtained was characterised by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), as well as galvanostatic measurements. The results indicate that, by employing the carbon pre-coating process, the carbon-coated nanostructured Li₄Ti₅O₁₂ can maintain the initial morphologies of the TiO₂ precursors and also show significant improvement in the rate capability for lithium-ion intercalation due to both good electronic conductivity and the short lithium-ion diffusion path.