First-principles simulations showed that, while Li motion through nanotube side-walls was impossible, the Li ions could enter tubes through topological defects which contained at least 9-sided rings, or through the ends of open-ended nanotubes. Once inside, their motion was not diffusion-limited. These results suggested that the damaging of nanotube ropes by chemical or mechanical means would yield a superior material for electrochemical storage.

Ab Initio Investigations of Lithium Diffusion in Carbon Nanotube Systems. V.Meunier, J.Kephart, C.Roland, J.Bernholc: Physical Review Letters, 2002, 88[7], 075506 (4pp)