Comparative Study of Sodium and Lithium Intercalation and Diffusion Mechanism in Black Phosphorus from First-principles Simulation

Abstract Experimentally, black phosphorus (BP) displays a promising electrochemical performance as an anode for both Li ion and Na ion batteries. The feature of fast charge–discharge capability is very desirable for an anode material. We investigated the intercalation mechanism of a single Na and Li and the diffusion mechanism in BP by means of first-principles simulation. We found that a large tunnel forms because of the sliding of phosphorus interlayers with a single Na and Li intercalation and that the Na and Li diffusion within the tunnel along the a axis is very fast. This makes BP a competitive and promising anode for both Na ion and Li ion batteries. The different behaviors of Na and Li in BP are also discussed.