Tunable Properties of Two-Dimensional Bilayer C3n as Anode Material: Bandgap, Binding Energy, and Diffusion Barrier

Numerous studies have demonstrated that adjusting the stacking pattern of bilayer materials can modulate their electrical properties. However, whether such adjustments can also influence other properties of the material still requires further examination. In this work, the potential of bilayer C3N with various stacking structures as anode materials for lithium-ion batteries was systematically investigated through first-principles calculations. The calculated results show that the bilayer C3N possesses good regulable electronic properties (band gap range from 0.35 to 0.90 eV), Li binding strength (the adsorption energy of Li range from -1.60 to -0.73 eV) and Li migration capability (the interlayer migration barrier of Li range from 0.082 to 0.580 eV). Notably, the AA' stacked structure exhibits an ultrafast interlayer migration channel for Li (the lowest interlayer migration barrier of 0.082 eV) and lowest bandgap of 0.35 eV. Further research revealed that the formation of ultrafast Li migration channels in the AA' stacking structure results from the combined effect of charge transfer and layer distance. These results provide a new strategy for modulating the electronic properties and the diffusion properties of ion in 2D van der Waals materials.