The influence of point defects on Na diffusion in black phosphorene: First principles study

Abstract

Two-dimensional layered materials like graphene, phosphorene and silicene are promising materials for use as anodes in Li- and Na-ion batteries. However, during synthesis of these materials, point defects – single vacancy (SV), divacancy (DV) or Stone–Wales (SW) type – are quite likely to form and to change the performance as an anode material. In this study, the influences of these defects on Na adsorption performance in black phosphorene are investigated. We conclude that these defects could affect performance of phosphorene as an anode material: negatively in the case of DV-2, SV and SW-2 defects but positively for DV-1 and SW-1 defects. This impact on the performance is greatest in both paths (zigzag and armchair) for SW-2 defects with the diffusion coefficient almost zero. However, the SW-1 and DV-1 defects could improve Na diffusion in phosphorene making these desirable for phosphorene as anode material for Na-ion batteries.