First principles study of blue phosphorene heterostructures as Li-ion battery anode materials

Abstract

The pursuit of high-performance anode materials for Li-ion batteries is crucial for portable electronic devices and electric vehicles. Blue phosphorene (BP) and silicene, with their graphene-like layered structures, exhibit high theoretical specific capacity and good conductivity. In this study, the potential of the BP/Si heterostructure as an anode material for Li-ion batteries was systematically explored based on vdW corrected density functional theory (DFT). The results demonstrated that Li exhibits the most stable adsorption energy of −1.82 eV on BP/Si, significantly lower than that on the pristine monolayers of BP and silicene, indicating good structural stability. The BP/Si heterostructure showed a minimum diffusion barrier of only 0.2 eV for Li diffusion and a high diffusion coefficient of 3.21 × 10⁻⁶ cm² s⁻¹ at room temperature, indicating excellent rate performance. With an increasing Li concentration, the BP/Si heterostructure achieved a high theoretical specific capacity of 472 mA h g⁻¹. Furthermore, the BP/Si heterostructures retained their respective electronic properties, including a low band gap of 0.26 eV and direct semiconductor characteristics, providing good conductivity.