Structural, Electronic, and Transport Properties of Phosphorene-Graphene Lateral Heterostructure Anodes: Insights from First-Principles Calculations

Edge reconstruction is a major challenge for the application of black phosphorus nanosheets as anodes of lithium-ion batteries. Recently, it was reported that a lateral heterostructure of black phosphorus flakes linked with graphite flakes as an anode material is capable of operating under high rate and high capacity. This raises some interesting problems concerning the geometry, P-C bonding property, and transport property of the heterostructure. In this paper, we first demonstrated energetically the stability of the phosphorene-graphene lateral heterostructure (BP-G) employing first-principles calculations. Furthermore, it is further revealed that the phosphorus and carbon atoms of the BP-G are strongly bonded by sp(2)-hybridized mode, and the electronic conductivity of the combined system is significantly improved compared with that of isolated phosphorene. Besides, it is found that BP-G allows strong Li adsorption, offering a theoretical specific capacity higher than or similar to graphite and phosphorene. Li migration from the interface to phosphorene side is confirmed to be fast along the zigzag direction, owing to a low barrier of , similar to 0.12 eV, which is much lower than that of edge reconstructed phosphorene. These results give an underlying explanation to the performance of the BP-G as an anode of lithium-ion batteries.

Automated summary

Edge reconstruction is a challenge for black phosphorus nanosheets as anodes in lithium-ion batteries, but a lateral heterostructure of black phosphorus and graphite flakes has shown potential for high-rate and high-capacity operation. In this study, the stability of the phosphorene-graphene lateral heterostructure (BP-G) was demonstrated using first-principles calculations. The strong sp(2)-hybridized bonding between phosphorus and carbon atoms in BP-G improved the electronic conductivity compared to isolated phosphorene. BP-G also exhibited strong Li adsorption and fast Li migration along the zigzag direction due to a low migration barrier. These findings provide insights into the performance of BP-G as a lithium-ion battery anode.