The influence of self-ordered TiO2 nanotubes microstructure towards Li+ intercalation

Abstract: In this work, TiO₂ nanotubes were prepared by anodization at a constant voltage in an electrolyte composed of fluoride species provided by ionic liquid (1 or 5 vol.%), applying 40 or 80 V. Different tube diameters (21.6, 34.8, 93 and 154.5 nm) were obtained, all of them presenting anatase crystalline phase with distinctive crystalline sizes and lattice strains. The Li-ion intercalation/deintercalation was studied and analysed in the light of crystalline structure changes. The amount of Li⁺ irreversibly trapped was higher for the samples with larger TiO₂ nanotubes compared to narrower ones. This behaviour was correlated with the lattice strain observed in the samples.