First-principles study of a substitutionally doped phosphorene as anode material for Na-ion batteries

An effective strategy to design high-performance anode materials is a significant task for rechargeable batteries technologies. Recently, sodium-ion batteries have attracted extensive attention because can be considered as an alternative for lithium-ion batteries in large-scale renewable energy storage applications due to abundant sodium resources and similar electrochemical mechanisms. In this paper, the first-principles density-functional theory calculations have been carried out to estimate the potential prospects of substitutionally doped monolayer of black phosphorus (BP) as an anode material for Na-ion batteries. It was found that the BP monolayer has negative binding energies for Sc, Co, Cu, B, F, and Cl dopants. Moreover, it was also shown that after sodium adsorbing, F and Cl atoms diffuse from phosphorene lattice on the surface of Na, which eliminates these materials from application in energy storage systems. Given these advantages, it is expected that Sc-, Co-, Cu- and B-doped phosphorus monolayers are promising anode materials for Na-ion batteries, with a maximum value of specific capacity of 438.6 mAh/g for B-doped system.