Ab initio molecular dynamics study on the disordered Li-Ga-Sn system.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Eutectic Gallium-Tin (GaSn) liquid metal alloys are potential anode materials for lithium-ion batteries, offering solutions to dendrite growth and volume expansion issues.
• The microstructural and physical properties of lithiated GaSn alloys remain unclear, hindering their practical application.

Purpose of the Study:

• To investigate the structural and physical properties of lithiated GaSn alloys using computational methods.
• To elucidate the mechanism of lithiation in GaSn alloys and its effect on the material's properties.

Main Methods:

• Employing *ab initio* molecular dynamics simulations to study the disordered Li-Ga-Sn system.
• Calculating radial distribution functions, structure factors, and bond angle distributions to analyze local structure.
• Investigating equilibrium density, thermal expansion coefficient, mixing enthalpy, self-diffusion coefficients, and viscosity.

Main Results:

• Lithiation of GaSn alloys is an exothermic process.
• Diffusion coefficients of Li, Ga, and Sn generally decrease with increasing lithium content.
• The lithiation process induces a transition from a liquid to a solid-like structure in the GaSn alloy, becoming more pronounced with higher lithium content.
• Stronger chemical interactions between Li-Sn and Li-Ga compared to Ga-Sn were observed, with Li preferentially bonding with Sn.

Conclusions:

• The study clarifies the microstructure and physical properties of lithiated GaSn alloys, crucial for battery anode development.
• Computational findings indicate that lithiated GaSn alloys form solid-like structures, enhancing stability in lithium-ion batteries.
• Understanding the preferential bonding of lithium with tin provides insights for optimizing anode performance and design.