The structure and energetics of Li atoms intercalated in a graphite lattice were investigated by Hartree-Fock calculations on clusters of LiC20 and Li2C32 with particular emphasis on minima and saddle points of the potential energy surface. These results were used in a Monte Carlo simulation for the diffusion of lithium through a graphite lattice. The screened Coulomb interactions between the Li atoms, were ionized in the lattice, and the energy barrier encountered at the surface could given rise to rather unusual concentration profiles with a sharp maximum on the side where the Li atoms leave the lattice.

The Diffusion of Lithium through Graphite: a Monte Carlo Simulation Based on Electronic Structure Calculations. Lehnert, W., Schmickler, W., Bannerjee, A.: Chemical Physics, 1992, 163[3], 331-7

Figure 13

Diffusion of Li in graphite

White circles: 6Li, black circles: 7Li