Computer Study of Atomic Mechanisms of Intercalation/ Deintercalation of Li Ions in a Silicene Anode on an Ag (111) Substrate

Abstract

The ability of silicon to hold a large amount of lithium puts silicene in a series of the most promising materials for the anode of lithium-ion batteries. An increase in the rate of movement of lithium ions through silicene can be achieved with silicene having vacancy-type defects. The effect of vacancy-type defects on the fill ability with lithium of the channel formed by silicene sheets on the Ag (111) substrate, as well as on the structural and kinetic properties of lithium, has been studied by the molecular dynamics method. The limit number of intercalated lithium atoms and their self-diffusion coefficient increase with the transition from the perfect silicene channel to the channel containing mono- and bivacancies. The lithium structure in the channel was studied using the method of statistical geometry. The packing of the lithium atoms in the channel turns out to be partially ordered due to the regular placement of some of the atoms at their fixation opposite the centers of hexagonal Si-cells. The σzz stress in the sheets of silicene decreases during intercalation of lithium and increases at the final stage of deintercalation.