Theoretical studies of Li incorporation into Si(111)

The incorporation of Li atoms into Si(111) is studied with the aid of density functional theory (DFT). We find that Li adsorption removes the (1 × 2) reconstruction on this surface. For the whole range of chemical potential values of Li at which Li adsorption occurs, only a high coverage structure (1 ML) is stabilized on unreconstructed Si(111). We find for this surface that the simultaneous penetration of two or more Li atoms into the subsurface is very unfavorable. However, the penetration barrier for a single Li atom into the subsurface on 1 ML-Li/Si(111) is very similar to that on clean Si(111). The present work can help us to better understand the process of Li insertion into Si anodes of Li-ion batteries.