Metallic BSi3 Silicene: A Promising High Capacity Anode Material for Lithium-Ion Batteries

Very recently, intrinsically metallic B-substituted silicenes, namely, H-BSi3 and R-BSi3 (H and R denote the hexagonal and rectangular symmetry), have been predicted as the global minimum structures of the BSi3 monolayer (J. Phys. Chem. C 2014, DOI: 10.1021/jp507011p). With unusual planar geometry and better electronic conductivity relative to the buckled and semimetallic pristine silicene sheet, the B-substituted silicenes are expected to have good applications in high capacity lithium-ion batteries (LIBs) anodes. By means of density functional theory (DFT) computations, we systematically investigated the adsorption and diffusion of Li on H-BSi3 and R-BSi3, in comparison with silicene and graphite. Their exceptional properties, including good electronic conductivity, very high theoretical charge capacity (1410 and 846 mA.h/g for single- and double-layer, respectively), fast Li diffusion, and low open-circuit voltage (OCV), suggest that the BSi3 silicene could serve as a promising high capacity and fast charge/discharge rate anode material for LIBs.