Permeability and mechanical properties of arsenene and arsenene/graphene heterostructure: First-principles calculation

Two-dimensional lithium metal anode protective films play an important role in inhibiting dendrite growth to improve the performance of batteries. In this work, the lithium ion diffusion barrier and mechanical strength of arsenene and arsenene/graphene heterostructure are investigated by first-principles calculation. Arsenene with vacancy defects has a low migration barrier but weak plane stiffness and poor rigidity, which may not be effective in suppressing the formation of dendritic lithium. In order to improve the mechanical strength while ensuring the low diffusion barrier, hard graphene is introduced to cover the upper arsenene layer. The arsenene/graphene heterostructure with vacancy defects is found to possess higher mechanical strength due to van der Waals interactions of the interlayer as well as the larger Young's modulus of graphene. An ultralow lithium ion diffusion barrier can be obtained from the heterostructure and our results provide insights and guidelines on how to design the suitable protective films and improve the performance of lithium-ion batteries.