Crystal structures and electronic band structures for hypothetic lithium boron nitride intercalation compounds

Although Li-BNICs (lithium boron nitride intercalation compounds) have been successfully synthesized by heat treatment, their crystal structures are still not clearly understood and controversial. In this study, several hypothetic phases of Li-BNICs are postulated and their phase stabilities are calculated through applying DFT (density functional theory), a common tool in first principles calculations. According to the experimental results on Li-BNICs, disordered structures have been suggested, which is also analyzed by introducing VCA (virtual crystal approximation) method for a disorder calculation. Lattice parameters, formation energies and electronic band structures for hypothetic Li-BNICs are estimated, where the VCA disorder calculation agrees well with experimental results, exhibiting negative formation energies. Li(BN)9 and Li(BN)3 are suggested as possible phases for Li-BNICs.