Two-Layer Silicene on the SiC Substrate: Lithiation Investigation in the Molecular Dynamics Experiment

The functioning of the lithium-ion battery anode composed of silicene/SiC composite is studied by molecular dynamics. In this composite, silicene has multiple vacancy defects. Approximately the same degree of lithium filling in such an anode is considered for both horizontal and vertical intercalations. During the horizontal intercalation lithium atoms not only fill the channel and deposit on its walls, but also penetrate into the substrate. In both cases, the self-diffusion coefficients of lithium atoms have similar values. However, the process of filling the system with lithium occurs with a smoother total energy change when the intercalation is performed vertically. A detailed study of the lithium atoms packing via the construction of Voronoi polyhedra for each of the systems under consideration shows the better uniformity of the Li atoms distribution over the volume of the system during the vertical intercalation.