▎ 摘　　要

The interaction potential of a Li atom with a graphene layer is calculated using the local density approximation to the density functional theory. Two configurations corresponding to different separations between Li in neighboring supercells were considered to determine the effect of Li-Li interaction on the binding of Li to graphene. The equilibrium position of Li is not affected by the Li-Li interaction and remains the same in both cases. It is equal to 3.1 a.u. above graphene with the Li at the center of a hexagonal ring formed by the carbon atoms. However, the binding energies differ substantially in the two configurations. The binding energy of Li is 0.934 eV in configuration A when the Li-Li separation in adjacent supercells is 9.22 a.u. The binding energy is 1.598 eV in configuration B corresponding to a separation 18.45 a.u. between adjacent Li atoms. There is substantial charge transfer from both lithium and carbon atoms (including those that do not surround the lithium) to a region between the Li and graphene at the minimum energy configuration. The interaction potential for both configurations can be fitted to a sum of a screened Yukawa potential and a linear superposition of power-law functions of type r(-n), where n is an integer. The density functional theory underestimates the attractive contribution of dispersion forces for large separations. The attractive interaction potential calculated for Li positions much greater than the equilibrium distance from graphene may therefore need to be corrected.