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Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
Computational studies of ionic liquids: size does matter and time too.
Sonja Gabl1, Christian Schröder, Othmar Steinhauser
1University of Vienna, Department of Computational Biological Chemistry, Vienna, Austria.
The Journal of Chemical Physics
|September 11, 2012
Summary
Molecular dynamics simulations reveal that system size significantly impacts ionic liquid dynamics. At least 500 ion pairs are crucial for accurate simulations, with size dependence outweighing time dependence.
Area of Science:
- Computational Chemistry
- Materials Science
- Physical Chemistry
Background:
- Molecular dynamics (MD) simulations are vital for understanding ionic liquid behavior.
- Determining appropriate system sizes and simulation times is critical for reliable MD results.
Purpose of the Study:
- To systematically analyze the size and time dependence of molecular dynamics simulations for ionic liquids.
- To establish guidelines for accurate simulation parameters in ionic liquid research.
Main Methods:
- All-atom force field-based MD simulations were performed.
- Simulations covered system sizes from 8 to 2000 ion pairs and trajectory lengths up to 70 ns.
- Analysis included structural, single-particle, and collective dynamics.
Main Results:
- Approximately 50 ion pairs suffice for structural analysis, but at least 500 ion pairs are required for accurate dynamics.
- Larger systems exhibit a linear relationship between dynamical properties and inverse box length, explainable by hydrodynamics.
- Consistent dynamical properties necessitate simulation times of 20-30 ns.
Conclusions:
- System size is a dominant factor influencing MD simulation accuracy for ionic liquids.
- Size dependence must be prioritized over time dependence in simulation setup.
- Hydrodynamic theories can rationalize the observed size-dependent diffusion coefficients.
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