Computational insights into the application of V2NS2 monolayer as anode material for Li/Na/K alkali metal-ion batteries

The electrochemical performance of Li/Na/K alkali metal ions on the monolayer V2NS2 battery electrode are investigated based on first-principles calculations. The V2NS2 monolayer shows excellent electrical conductivity, and the good adsorption effect on alkali metal ions (-1.48 eV to-2 eV) indicates a stable interaction between the alkali metal ions and the substrate. The extremely low diffusion barriers for Li/Na/K on V2NS2 (0.198 eV, 0.073 eV, 0.045 eV) suggest that it appears rapid ionic diffusion capabilities and electrode reversibility on the V2NS2 monolayer. Furthermore, the average OCV for alkali metal ions on the V2NS2 monolayer is predicted to range from 0.38 V to 0.86 V, ensuring the safety of the electrode. The theoretical capacities of 1191.2 mAh/g, 495.8 mAh/g, 198.5 mAh/g is obtained for Li/Na/K adsorption on the V2NS2 monolayer, respectively. The hydrophilicity of V2NS2 is conducive to the combination with aqueous binders during the preparation process. Slight O-doped of V2NS2 can also enable the substrate material to maintain good electrical conductivity and diffusion properties. In summary, the intriguing electrochemical properties of V2NS2 as an anode material for Li/ Na/K alkali metal-ion batteries are expected to provide a theoretical impetus for the advancement of secondary battery technology.