SusChEM: Nonflammable, Highly Conductive Ionic Liquid based Organic-Inorganic Hybrid Electrolytes for Lithium Batteries

Lithium ion batteries have great potential to reduce dependence on fossil fuels for transportation and play a critical role in moving the U.S. toward a sustainable, clean energy future. The electrolyte, an essential component of a battery, allows the flow of electrical charge between the electrodes. Lithium-ion batteries typically use a mixture of volatile organic solvents and salts as electrolytes, which creates potential safety and reliability concerns. This research will develop a new class of nonflammable organic-inorganic hybrid Li-ion electrolytes. The research will lead to improved understanding of fundamental mechanisms of ion conduction and electrochemical properties of the solid-state electrolytes. The scientific aspects of the research program will be integrated with broader outreach and educational initiatives in the science, technology, engineering, and mathematics (STEM) fields. Additionally, this project will include international collaboration with Seoul National University in South Korea to give the students valuable experience in the international research and education.

This research will address ionic liquid-based nonflammable, solid-state Li-ion electrolytes. The project includes synthesis, characterization, and ion transport in ionic liquid tethered polyhedral oligomeric silsesquioxane (POSS-IL) mixtures with lithium bistrifluoromethanesulfonimidate) salts (LiTSFI). The research will explore how tuning the interactions between the cationic structures and immobilized anions could affect ionic conductivity and electrochemical properties. The project will include the systematic variation of chemical structures of electrolytes to gain fundamental insight into how molecular structures, e.g. cationic structures and immobilized anions, affect lithium ion conductivity and electrochemical properties. The synthetic effort will be closely coupled with Raman spectroscopy, electrochemical property and battery performance measurements to create a complete picture of structure-property-performance relationships. Dielectric spectroscopy will be utilized to uncover the mechanisms of ion dissociation and transport. The project will generate fundamental understanding of the relationship between molecular structure and ion transport.