Kinetically Corrected Monte Carlo-Molecular Dynamics Simulations of Solid Electrolyte Interphase Growth

Area of Science:

• Computational Chemistry
• Materials Science
• Chemical Engineering

Background:

• Simulating reactive liquids is challenging due to the need for complex potential energy surfaces.
• Existing methods often struggle to accurately capture the dynamics of chemical reactions in condensed phases.
• Understanding the solid electrolyte interphase (SEI) formation is crucial for improving lithium-ion battery performance.

Purpose of the Study:

• To introduce a novel kinetic approach to Monte Carlo-molecular dynamics (MC-MD) for simulating reactive liquids.
• To enable the simulation of complex reactions and their local solvation environments.
• To investigate the development of the solid electrolyte interphase (SEI) in lithium-ion batteries.

Main Methods:

• Developed a kinetic MC-MD method utilizing nonreactive force fields.
• Implemented a graphical reaction representation for defining reactions of arbitrary complexity.
• Derived reaction probabilities and simulation times from ab initio calculations.
• Validated the method through detailed simulations.

Main Results:

• Successfully simulated the development of the solid electrolyte interphase (SEI) in lithium-ion batteries.
• Reproduced the experimentally observed two-layered SEI structure on graphite.
• Identified a near-shore aggregation mechanism responsible for the SEI structure formation.
• Demonstrated the capability to model local solvation environments during reactions.

Conclusions:

• The kinetic MC-MD approach provides a powerful tool for simulating reactive liquids.
• The method accurately captures the formation mechanism of the SEI in lithium-ion batteries.
• The findings offer insights into battery degradation and potential strategies for enhancement.