Ab initio calculations of lithium titanates related to anodes of lithium-ion batteries

We perform ab initio calculations, within the density functional theory framework, of different lithium titanate compounds. In particular, Li₄Ti₅O₁₂ (whose lithiated form is Li₇Ti₅O₁₂) can be used as an anode in Li-ion batteries. Because of the complexity of the structures of these compounds, the related compounds LiTi₂O₄ and Li₂Ti₂O₄ are analyzed in the first stage of this work. In a later stage, the Ti atoms in these compounds are systematically replaced by Li atoms at the corresponding crystallographic sites to build the structure of the compound of interest. Analysis of the chemical potential allows us to determine the regions of relative stability of each of the intermediate structures obtained by means of the aforementioned replacements. Additionally, experimental structures are reported and Li+ diffusion velocities are calculated.