Chirality dependence of the energetics and electronic properties of Li-intercalated 4 إ carbon nanotubes

Using first principles calculations, we explore the energetics of intercalating Li atoms into the interior of 4 إ diameter single-wall carbon nanotubes. The change of electronic structure induced by Li intercalation is studied and we find that a rigid-band picture offers a good description near the Fermi level. There is a marked dependence of the Li binding energy on the chirality of the 4 إ tubes, which is traced to the different electron affinity of these tubes. We also find that for the (5,0) tube, there is a range of Li doping concentration in which the energy is favorable and the density of states at the Fermi level increases significantly.