Computational Study of Coarse-Grained Aqueous Ionic Liquid Solutions

The air transportation system is a major part of the United States and global economies. For the U.S. aviation industry to continue to grow, NASA has launched the Advanced Air Vehicles Program with the goal to make the nation's air transportation system more efficient, safe, and sustainable. Hybrid electric aircraft that is characterized with high energy efficiency, low emissions, and reduced noise is proposed to achieve this green aviation's goal. However, currently available battery technology limits hybrid electric aircraft development. The application of new electrode materials together with alternative electrolytes based on ionic liquids have the potential to enable safe high energy batteries. Ionic liquids are appealing electrolytes because they have low volatility, moderate reactivity, low flammability, a wider liquid range, and more electrochemically stable than most organic solvents. However, there are several major constraints that prevent ionic liquids from commercial applications: (1) large amount of expensive ionic liquids is required; (2) recycling of pure ionic liquids is energy- intense process; (3) extremely viscous electrolytes deliver low conductivity, thus significantly reducing battery performance. The focus of this project is to use computer simulation techniques to study the feasibility of aqueous ionic liquid solutions and compare results with those obtained from pure ionic liquids. The specific goals of this project are: (1) Based on the computation data obtained at NASA Ames Research Center develop new coarse-grained models for ionic liquid electrolytes; (2) Develop new coarse-grained force field for a system of bulk water based on molecular dynamics (MD) utilizing polarizable force field simulations; (3) Perform coarse- grained molecular dynamics (CGMD) simulations of aqueous ionic liquids at larger time and length scales for accurate prediction of structure, dynamic, and thermodynamic properties. The proposed project is applicable to several important NASA applications in both aeronautics, e.g. hybrid electric aircraft, space technology, e.g. rovers, ISS, Human Exploration and Operations Mission Directorate, etc. that require advanced energy storage technology. Specifically, the proposed work is aligned with the technology development prioritizes of Aeronautics Research Mission Directorate, Advanced Air Vehicles Program. This project is also aligned with the national and Kentucky Statewide NASA EPSCoR Program Objectives as well as the Space Technology Mission Directorate, and Advanced Space Power Systems project. This project will be performed in collaboration with researchers at the NASA Ames Research Center.