Exploring lithium-ion diffusion and electronic properties in defective graphite via molecular dynamics and density
Zhaoqi Ren1,2, Ding Shen1, Yanzhen Ji1
1College of Materials Science and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, China.
The Journal of Chemical Physics
|August 11, 2025
Summary
Defects in graphite anodes impact lithium-ion battery performance by altering diffusion and mechanical stability. Understanding these defect effects is key for designing better battery materials.
Area of Science:
- Materials Science
- Electrochemistry
- Computational Physics
Background:
- Graphite anodes are crucial for lithium-ion battery performance.
- Defects in graphite structure can significantly alter its properties.
Purpose of the Study:
- To investigate the impact of Stone-Wales (SW), single vacancy (SV), and double vacancy (DV) defects on graphite's thermodynamic, kinetic, and mechanical properties.
- To analyze how defect density affects graphite density, charge transfer, voltage, lithium-ion diffusion, and mechanical stability.
Main Methods:
- Molecular dynamics simulations
- Density functional theory calculations
- Analysis of defect configurations (bridge, ylide, spiro)
Main Results:
- Structural stability decreases in the order SV > SW > DV.
- Lithium-ion diffusion coefficient decreases with increasing defect density at high lithium concentrations but increases at low concentrations.
- Increasing defect density significantly reduces Young's modulus and ultimate tensile strength.
Conclusions:
- Defects introduce localized electronic states, influencing lithium-ion diffusion and disrupting graphite structure.
- Defect engineering is critical for optimizing graphite anode performance.
- Findings provide insights for designing advanced anode materials.
