Theoretical investigations were made of the diffusion of lithium on the outside and inside of single-walled carbon nanotubes. It was found that lithium could be adsorbed at both the interior and exterior surfaces, with an adsorption energy of about -2.44eV. The Li had a higher mobility, with diffusion barriers of less than 0.2eV on both the exterior and interior of the nanotubes. The diffusion barriers (exo- and endohedral) of lithium depended upon the radius and chirality of the nanotubes. The lithium trapped inside the nanotubes increased with increasing tube diameter and could be as high as LiC2.6 in a (10,10) nanotube. These lithium atoms tended to form single- or multi-shelled co-axis nanotubes, together with a linear atomic chain in the axis at low temperatures; depending upon the diameter of the nanotube.

Diffusion and Condensation of Lithium Atoms in Single-Walled Carbon Nanotubes. M.Zhao, Y.Xia, L.Mei: Physical Review B, 2005, 71[16], 165413