The intercalation and diffusion of lithium ions in a bundle of carbon nanotubes were investigated using an ab initio simulation method based upon density functional theory. It was found that lithium ions penetrated quickly into the nanotubes and the space between neighboring nanotubes. At a low Li ion density, the Li ions tended to stay close to the nanotube ends. The Li ions were able to penetrate through the carbon nanotube and moved from one end to the other. It was found that Li ions could remain between two neighboring nanotubes. Lithium ions located among three neighboring nanotubes had very strong adsorption potentials which were a factor of four larger than those for Li ions located along the central axis of a single-walled nanotube. This indicated that Li ions located among three neighboring nanotubes would be very difficult to remove from a nanotube bundle.

Intercalation and Diffusion of Lithium Ions in a Carbon Nanotube Bundle by ab initio Molecular Dynamics Simulations. Song, B., Yang, J., Zhao, J., Fang, H.: Energy and Environmental Science, 2011, 4[4], 1379-84