Na adsorption on bismuthene monolayer for battery applications: A first-principles study

Abstract Energy storage technologies in electric vehicles and electronic devices have generated an urgent need for alternative rechargeable batteries such as lithium-ion batteries (LIBs). The cost and limited resources of lithium in the earth's crust may be hindered by the LIBs applications. Due to abundant sodium resources and their similar electrochemical mechanisms, sodium-ion batteries (SIBs) are considered a potential alternative to lithium-ion batteries for large-scale renewable energy storage applications. Herein, based on first-principles density functional theory (DFT), the properties of Na atoms adsorbed on a bismuthene monolayer (ML) have been investigated. Our results exhibited the V site is the optimal adsorption position of Na atoms on ML-Bi with a negative adsorption energy of −1.55 eV and a significant charge transfer. As the adsorption energy of Na increases, the crystal structure of bismuthene tends to be changed significantly and reveals a tendency to form alloys. Also, semiconductor-to-conductor transitions have been observed. Of interest, the diffusion barrier of Na atoms in the NaxBi monolayer system was found to be very low (0.18 eV). This latter would facilitate the insertion/extraction of ions into the electrode material and improves the rate of charge and discharge. These predicted findings can pave the way for experimental studies leading to strong decision-making in the development of battery technology.