Theoretical investigations were performed in order to explore the diffusion of lithium on the exterior and interior of single-walled carbon nanotubes. It was found that lithium could adsorb on both interior and exterior surfaces with adsorption energy around -2.44eV. Lithium has a higher mobility with the diffusion barriers less than 0.2eV on both the exteriors and interiors of single-walled carbon nanotubes. The diffusion barriers (exo- and endohedral) of lithium depended upon the radius and chirality of single-walled carbon nanotubes. The lithium capacity trapped inside single-walled carbon nanotubes increased with increasing tube diameter and could be as high as LiC2.6 in a (10,10) single-walled carbon nanotube. These lithium atoms tended to form single- or multi-shelled coaxial nanotubes, together with a linear atomic chain in the axis at low temperature depending upon the diameter of single-walled carbon nanotubes, suggesting a potential means to synthesize small metal nanotubes and metal nanowires.

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