A graphene-MXene complex compound and graphite-like BC2

Abstract This review discusses the ternary borocarbide Sc2B1.1C3.2 and graphite-like (g-) BC2. Sc2B1.1C3.2 has a layered structure in which two types of layers, graphene-like BC2 and MXene-like Sc2C, are stacked alternately; hence, Sc2B1.1C3.2 can be regarded as a graphene-MXene complex compound. The X-ray diffraction structural analysis was ambiguous due to the close atomic numbers of B and C; however, the most stable structure determined by first-principles calculations had B atoms in the BC2 layer arranged in a √ 3 × √ 3 –R30° superlattice which was an intermediate between the already known BC3 and BC structures. Bulk g-BC2 has also been studied for potential application as the anode of Li-ion batteries. Calculation of the intercalation potential revealed that Li atoms can be intercalated into BC2 to yield Li1.5BC2, which has a specific capacity approximately 3.1 times that of graphite (LiC6).