Main content area

Staging Phenomena in Lithium-Intercalated Boron–Carbon

Kalkan, Bora, Ozdas, Engin
ACS applied materials & interfaces 2019 v.11 no.4 pp. 4111-4122
X-ray diffraction, anisotropy, cathodes, compressibility, isotropy, lithium batteries, models, superconductivity
Hole-doped LiBC has become of great interest as a candidate for high-temperature superconductivity with its structural similarity to MgB₂ and as a possible cathode for rechargeable lithium batteries with the large graphenelike BC hexagons. The limitation on synthesis studies has detracted from the structural and electronic properties and application studies of LiₓBC. Here, we present the successful synthesis of hole-doped Li₀.₅BC and its structural and electronic characterization using detailed structural modeling based on a unique stage-2 Daumas–Hérold-type domain structure consistent with X-ray diffraction data. The strong intralayer motion of the guest Li island induces extraordinary structural properties, such as staging and staging disorder, which are confirmed by the compressibility results obtained from Li₀.₈₅BC (anisotropic cell compressibility with B₀ ∼ 134 GPa) and Li₀.₄₈BC (isotropic cell compressibility with B₀ ∼ 190 GPa). Li deficiency increases the conductivity; however, the temperature-dependent conductivity is dominated by the thermal excitation of carriers in a strongly disordered regime with well-defined localized states.