Surface effects on the structure and lithium behavior in lithiated silicon: A first principles study

► We examine the surface effects on the lithiation behavior of amorphous silicon using density functional theory calculations. ► Li diffusivity is significantly enhanced in the near-surface region. ► When the Li content is sufficiently low, a slight Li surface enrichment contributes to the stabilization of the surfaces. ► As the Li content is further increased, the near-surface structure and alloy composition become similar to that in the bulk. ► The surface effects tend to be very shallow and only extend to the first couple of atomic layers.