SiP2 monolayer as potential anode material for Na/K-ion batteries predicted from first-principles calculations

Based on the density functional theory (DFT), a systematic feasibility analysis of monolayer SiP2 as potential anode material for Na/K-ion batteries has been carried out. Through ab-initio molecular dynamics (AIMD) calculation, the findings reveal exceptional stability of SiP2. The ultra-low ion diffusion barriers (0.107 eV for Na and 0.043 eV for K) and metallic properties following adsorption of alkali metal ions demonstrate that SiP2 exhibits a rapid charge and discharge rate and remarkable electrical conductivity when employed as an anode. Furthermore, it possesses a considerable theoretical storage capacity (Na/K: 446.53/595.38 mAh/g) and energy density (Na/K: 1026.91/1322.46 mWh/g). These findings suggest that monolayer SiP2 exhibits superior performance as potential anode material for Na/K-ion batteries.