Monolayer Mo₂C as anodes for magnesium-ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Magnesium-ion batteries (MIBs) are a promising alternative to lithium-ion batteries.
• Developing stable and high-capacity anode materials is crucial for MIB advancement.

Purpose of the Study:

• Investigate the adsorption and diffusion of magnesium on monolayer Mo₂C.
• Evaluate the structural stability and theoretical capacity of Mo₂C as an anode material for MIBs.

Main Methods:

• First-principles calculations based on density functional theory (DFT).
• Analysis of adsorption sites, diffusion pathways, and energy barriers.
• Assessment of volume expansion and theoretical gravimetric capacity.

Main Results:

• Magnesium preferentially adsorbs to H and T_C sites on Mo₂C with significant adsorption energies.
• Low energy barriers for Mg diffusion along H-T_C-H, H-B-H, and H-T_Mo-H paths.
• Mo₂C monolayer demonstrates mild volume expansion (0.7% to 7.08%) and a high theoretical gravimetric capacity of 469.791 mAhg^-1 at x=2.0.

Conclusions:

• Monolayer Mo₂C exhibits favorable adsorption and diffusion properties for magnesium ions.
• The material shows excellent structural stability and high theoretical capacity, suitable for MIB anodes.
• Mo₂C monolayer is identified as a promising candidate for next-generation magnesium-ion battery anode materials.