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

Abstract

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.