Theoretical Prediction of Blue Phosphorene/Borophene Heterostructure as a Promising Anode Material for Lithium-Ion Batteries

The heterostructured electrodes assembled with various two-dimensional materials break the limitation of the restricted properties of individual building blocks and combine the advantages of single material systems. Here, we design a novel blue phosphorus (BP)/borophene heterostructure by combing BP and borophene monolayers together. We investigate the adsorption and diffusion of Li along the outside surfaces and the interlayer of BP/borophene to assess its suitability as the Li-ion battery anode material. It is revealed that the BP/borophene heterostructure possesses excellent structural stability and high mechanical stiffness. In contrast to the semiconductor character of pristine BP monolayer, BP/borophene is metallic. The adsorption energy of Li on the BP side of the BP/borophene heterostructure is higher than that on the BP monolayer, and Li adsorption on the borophene side of the BP/borophene system is also stronger than that on the borophene monolayer. In addition, the BP/borophene heterostructure possesses a specific capacity of 1019 mA h g(-1), which is larger than those of pristine BP monolayer and other BP-based heterostructures. Moreover, it is found that the energy barriers are relatively low as Li diffuses in the BP/borophene. Given these advantages, that is, large adsorption energies, low diffusive energy barriers, high capacity, and electrical conductivity, we conclude that the BP/borophene heterostructure can be an excellent candidate as anode material for Li-ion batteries.