关键词: 第一性原理, 二维材料, 电极材料, 金属离子电池

Abstract: As promising alternatives to lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) have garnered significant interest owing to the abundant resources, low cost, and similar storage mechanism with LIBs. However, the lack of suitable anode materials is a major bottleneck of SIBs. Two-dimensional (2D) materials are promising anode materials for batteries due to their large surface area and short diffusion paths. In this paper, a pentagonal and heptagonal 2D semiconductor structure R57-BN composed of B and N atom is predicted, and the electrochemical properties of R57-BN as anode material of SIBs is systematically study based on first-principles calculations. 2D R57-BN shows great stability in dynamic and thermodynamic aspects. The computation results reveal that Na atom can be adsorbed on R57-BN without clustering, and the adsorbed energy of Na-ion on the R57-BN is 1.55 eV. Even at low intercalated Na concentration, the Na adsorbed R57-BN system demonstrates metallic characteristics, showing good electronic conductivity. The diffusion barrier of Na diffusion on the surface of R57-BN is as low as 0.55 eV. Meanwhile, R57-BN has high specific capacity (662.40 mA h g-1) and suitable average OCV (0.50 V). Based on the above results, R57-BN can serve as a potential anode material for SIBs. The present research can provide a good theoretical basis and thus conduce to guiding the developing of good Na storage materials, and also supply strong background for experimental researches.

Key words: First-principle calculations, Two-dimensional material, Electrode material, Metal-ion batteries