Collaborative Research: Catholyte Molecular Design For Non-aqueous Mg-organic Hybrid Redox Flow Batteries

With support of the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Tao Gao of the Department of Chemical Engineering at the University of Utah, and Chao Luo at the Department of Chemistry and Biochemistry at George Mason University are developing new classes of organic molecules for energy storage technologies. The objectives of this project are to design, synthesize and characterize core-shell structured organic molecules, to gain a fundamental understanding of the structure-property-performance correlation of synthesized organic molecules, and to leverage this understanding for designing a transformative hybrid flow battery for future energy storage applications. The project offers several broader impacts, including fundamental knowledge of organic molecules, novel battery technology development, training of the future science and technology workforce at undergraduate and graduate levels, and an outreach program that can engage high school students including students from groups traditionally underrepresented in chemistry and chemical engineering. To unleash the potential of hybrid magnesium-organic flow batteries, new organic molecular structure design is proposed. The design consists of core-shell structured organic molecules with an aromatic core, a redox-active shell, and a polyether chain connecting them. Such core-shell structured molecules have the potential to enable fast electron-transfer reactions to the redox-active moieties located in the shell, and provides multiple design freedoms to tune the solubility, capacity, potential, and stability of organic molecules. Thus, this approach has great potential to achieve transformative energy storage performance compared to the state-of-the-art hybrid flow batteries. A systematic experimental study is proposed, including design and synthesis of core-shell structured organic molecules, chemical and electrochemical characterization of the synthesized molecules, a device-level study of flow battery performance of synthesized molecules, as well as in situ/ex situ studies to understand reaction mechanisms and performance limiting factors. The overall long term aim is to achieve a comprehensive fundamental understanding of the structure-property-performance correlation of core-shell structured organic molecules for magnesium-organic flow batteries. The goal is to eventually provide rational structure/design guidelines of organic materials for high-voltage, high-capacity and stable non-aqueous magnesium-organic flow batteries. Such tunable organic molecules in the longer term have potential application areas that include supporting redox-flow batteries, CO2 capture, electrochemical sensing, organic electronics, and separations science. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.