Alkali-metal lithium on graphite monolayer surface: Theoretical study

We studied the adsorption stability of the alkali-metal Li atoms on the graphite monolayer surface by first-principles theoretical calculations. We found two stable adsorption structures of Li, i.e., the in-plane (√3×√3)R30° and (1×1)R0° triangular structures on both sides of graphite. It is supposed that, as the Li adsorption proceeds, the former appears first, and then the later is formed. We also found that the Li−Li interaction increases with the increase of the Li coverage. Furthermore, the second Li layer adsorption is more stable than the first layer adsorption. Thus, we suggest that such high-density adsorption becomes the precursor state for the Li dendrite formation that causes the breakage of the Li-ion electric cells.