Computational and experimental characterization of a pyrrolidinium-based ionic liquid for electrolyte applications

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Lithium-ion batteries are crucial for energy storage.
• Ionic liquids (ILs) are promising electrolytes but require accurate property data.
• Pyrrolidinium-based ILs are being investigated for battery applications.

Purpose of the Study:

• To synthesize and characterize a novel pyrrolidinium-based ionic liquid.
• To computationally determine thermodynamic and transport properties for IL electrolyte applications.
• To develop and validate a polarizable force field for IL simulations.

Main Methods:

• Synthesis of spirocyclic pyrrolidinium ([sPyr+]) ionic liquid.
• Development of a quantum mechanical-based, many-body polarizable force field.
• Molecular dynamics simulations with and without intramolecular polarization.
• Comparison of computational results with experimental data (isothermal titration calorimetry).

Main Results:

• Simulations with intramolecular polarization showed higher heat of vaporization and self-diffusion coefficients.
• Polarization effects led to lower predicted densities.
• Computational results showed good agreement with experimental data for similar ILs and the synthesized IL.
• The developed force field accurately captures inter-ionic interactions.

Conclusions:

• The synthesized pyrrolidinium-based ionic liquid shows potential for Li-ion battery electrolytes.
• Intramolecular polarization is a significant factor in accurately simulating IL properties.
• The validated computational model can guide the design of future IL electrolytes.