A computational study on the BN-yne sheet application in the Na-ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Lithium-ion batteries (Li-ion) face limitations including short lifespan, high cost, and safety concerns.
• Sodium-ion batteries (NIBs) offer a potentially cheaper, safer, and more sustainable alternative due to sodium's abundance and low toxicity.

Purpose of the Study:

• To investigate the potential of a graphyne-like boron nitride (BN-yne) layer as an anode material for NIBs.
• To evaluate the adsorption, migration, and electrochemical properties of sodium on the BN-yne surface using computational methods.

Main Methods:

• Density functional theory (DFT) calculations were employed to model the interaction of sodium (Na) and sodium ions (Na+) with the BN-yne structure.
• Adsorption energies, migration barrier energies, and cell voltages were computed under various conditions, including the application of an electric field.

Main Results:

• BN-yne exhibits strong adsorption for both Na and Na+ with calculated energies of -15.3 and -54.6 kcal/mol, respectively.
• The maximum migration barrier energies for Na and Na+ through the BN-yne surface are 20.2 and 16.5 kcal/mol, indicating good diffusion kinetics.
• The calculated cell voltage for BN-yne is 1.70 V, which increases to 2.10 eV under an applied electric field of -0.02 a.u., enhancing Na+ interaction.

Conclusions:

• BN-yne demonstrates a high sodium storage capacity (Na4B2N2), suggesting its suitability for high-performance NIB anodes.
• The material possesses favorable ion diffusion properties and a tunable high cell voltage, making it a promising candidate for next-generation NIB anode applications.