Theoretical Research of Two- dimensional Semiconductor R57-BN as Anode Material of Sodium- ion Battery

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 was predicted , and the electrochemical properties of R57 - BN as anode material of SIBs were studied 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 <middle dot> h/g ) and suitable average open circuit voltage ( V OC , 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.