Theoretical study of lithium intercalation in rutile and anatase

Motivated by recent developments concerning coloration and energy storage in lithium intercalated nanostructural TiO2, quantum chemical Hartree-Fock calculations have been carried out to study lithium atom intercalation in rutile and anatase. Equilibrium geometries and effective atomic charges were obtained for the rutile (110) and anatase (101) clean surfaces. Li-induced local one-electron energy levels were found in the gap between the upper valence band and the conduction band and could be attributed to Ti3+ states. The absorption energies obtained are compared with available experimental data. The equilibrium positions of the Li atom and its surrounding host atoms have been calculated for both structures. The results predict a higher possibility of lithium intercalation in the anatase structure than in rutile.