Promising anode material BN/VS2 heterostructure for the Li-ion battery: The first-principles study

Abstract

Although monolayer VS2 shows metal property and well Li storage property when as the anode for the Li-ion battery (LIB), the structural degradation problem cannot be ignored. Our results show BN/VS2 heterostructure can not only improve the poor stability of monolayer VS2 to achieve excellent structural stability and higher mechanical stiffness, but also change the insulator electronic property of BN monolayer into metallic, which are very important for the application of LIB anodes. The average adsorption energies of Li atoms on the BN sheet side and the VS2 monolayer side of BN/VS2 heterostructure are enhanced when compared to that on BN and VS2 monolayers respectively. The Li capacity of BN/VS2 heterostructure is 590.4 mAh/g and larger than that of VS2 monolayer (466 mAh/g) and graphene/VS2 heterostructure (569 mAh/g). As to the Li diffusion in BN/VS2 heterostructure, energy diffusion barrier of Li+ ion is relatively low (0.25 eV). In view of large Ead, low Ebarrier, high Li capacity and conductivity, BN/VS2 heterostructure should be a more ideal anode material for LIB than monolayer VS2 and graphene.