Intercalation of graphite and hexagonal boron nitride by lithium
Department of Chemistry, Abant Izzet Baysal University, Golkoy, 14280 Bolu, Turkey
2 Department of Physics, Abant Izzet Baysal University, Golkoy, 14280 Bolu, Turkey
Corresponding author: a email@example.com
Revised: 12 November 2010
Published online: 25 January 2011
Although graphite and hexagonal form of BN (h-BN) are isoelectronic and have very similar lattice structures, it has been very difficult to intercalate h-BN while there are hundreds of intercalation compounds of graphite. We have done a comparative first principles investigation of lithium intercalation of graphite and hexagonal boron nitride to provide clues for the difficulty of h-BN intercalation. In particular lattice structure, cohesive energy, formation enthalpy, charge transfer and electronic structure of both intercalation compounds are calculated in the density functional theory framework with local density approximation to the exchange-correlation energy. The calculated formation enthalpy of the considered forms of Li intercalated h-BN is found to be positive which rules out h-BN intercalation without externally supplied energy. Also, the Li(BN)3 form of Li-intercalated h-BN is found to have a large electronic density of states at the Fermi level and an interlayer state that crosses Fermi level at the zone center; these properties make it an interesting material to investigate the role of interlayer states in the superconductivity of alkali intercalated layered structures. The most pronounced change in the charge distribution of the intercalated compounds is found to be charge transfer from the planar σ states to the π states.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2011