Mechanism of storage of interhalogen compounds on single- and double- layered graphene nanoflakes: a density functional theory study

Abstract

Abstract Interhalogen compounds, such as bromine monochloride (BrCl), play an important role in aqueous Li-ion batteries. In this study, the interaction of BrCl with graphene nanoflakes (GRs) composed of single and double layers was investigated using the density functional theory (DFT) method. Both monomer and dimeric forms of BrCl were examined as interhalogen compounds. The binding energies of BrCl and (BrCl)2 with GRs were calculated to be 11.0 and 22.1 kcal mol−1, respectively. The diffusion barrier of BrCl on GRs was determined to be 1.9 kcal mol−1, which is significantly smaller than those of Li+ and Li on GRs (9.5 and 11.5 kcal mol−1, respectively). These results indicate that BrCl can easily diffuse across the GR surface, with its movement being faster than that of Li+ or Li. The electronic states of BrCl and (BrCl)2 on GRs, along with intercalation states, are discussed based on theoretical results.