WS2-Graphene van der Waals Heterostructure as Promising Anode Material for Lithium-Ion Batteries: First Principles Approach

In this work, we report the results of density functional theory (DFT) calculations on van der Waals (VdW) heterostructure formed by vertically stacking single-layers of tungsten disulfide and graphene (WS2/graphene) for employing them in Lithium-ion batteries (LIBs) as an anode material. The electronic properties of the heterostructure reveal that the graphene layer helps to improve the electronic conductivity of this hybrid system. Indeed, the charge transfer from Li to WS2/graphene heterostructure further improves their metallic character. Moreover, the Li binding energy in this heterostructure was higher than that of Li-metal's cohesive energy, which indicates the possibility of Li-dendrite formation in this WS2/graphene electrode is low. In addition, the effect of heteroatoms like boron (B) and nitrogen (N) doping on the graphene layer of the heterostructure on Li-adsorption ability is also explored here. The results suggest that B-doping improves the Li-adsorption energy. Interestingly, the computed open-circuit voltage (OCV) and Li-diffusion energy barrier also favor that this heterostructure can act as a promising anode material for LIBs.