Hybrid density functional theory calculations were carried out for lithium ion-carbon cluster model systems in order to clarify the nature of lithium-carbon surface interaction. Direct molecular orbital calculations were also applied to the diffusion of Li ions on the model surfaces of amorphous carbon. Seven cluster models (n = 7, 14, 19, 29, 37, 44 or 55, where n was the number of rings in the carbon cluster models) were considered. The calculations showed that the lithium ion was located about 1.60Å from the carbon surface. The direct molecular orbital calculations showed that the Li ion diffused freely on the surface above 250K. At 1100K, the Li ion moved from the center to the edge region of the model surface and left the surface.

A Direct Molecular Orbital-Molecular Dynamics (MO-MD) Study on the Diffusion of Alkaline Ions on Amorphous Carbon. Iyama, T., Kawabata, H., Tachikawa, H.: Molecular Crystals and Liquid Crystals, 2007, 472[1], 307-14