Functionalized two-dimensional iron boride compounds as novel electrode materials in Li-ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Two-dimensional metal borides (MBenes) are emerging as advanced electrode materials for energy storage applications.
• Iron boride (FeB) is a MBen with potential for use in lithium-ion batteries (LIBs).

Purpose of the Study:

• To systematically investigate the performance of two-dimensional iron boride (FeB) as an electrode material for lithium-ion batteries (LIBs).
• To explore the impact of surface functionalization on the electrochemical properties of FeB for enhanced lithium storage.

Main Methods:

• First-principles calculations were employed to study the structural stability, conductivity, and electrochemical performance of FeB.
• The adsorption of lithium atoms, theoretical capacity, open circuit voltage (OCV), and diffusion barrier energy were calculated.
• The effects of surface functionalization with F, O, and S on FeB's properties were investigated.

Main Results:

• FeB exhibits excellent structural stability and conductivity, with a theoretical capacity of 364 mA h g^-1, an average OCV of 1.08 V, and a low diffusion barrier of 0.24 eV.
• Surface functionalization positively impacts lithium storage, with theoretical capacities reaching 538 mA h g^-1 (FeBF), 555 mA h g^-1 (FeBO), and 476 mA h g^-1 (FeBS).
• F and O functionalization significantly reduced diffusion barriers to 0.081 eV and 0.036 eV, respectively, while S functionalization decreased OCV to ~0.25 V.

Conclusions:

• FeB is a highly promising electrode material for LIBs due to its inherent stability and conductivity.
• Surface functionalization offers a viable strategy to tune FeB's electrochemical properties for improved lithium storage.
• FeB and its functionalized derivatives hold significant potential for the future development of high-performance lithium-ion batteries.