Dissertations, Theses, and Capstone Projects

Date of Degree

6-2020

Document Type

Dissertation

Degree Name

Ph.D.

Program

Chemistry

Advisor

George John

Committee Members

Mark Biscoe

Spiro Alexandratos

Robert J. Messinger

Subject Categories

Materials Science and Engineering | Nanotechnology | Organic Chemicals | Polymer and Organic Materials | Polymer Science | Power and Energy

Keywords

Green Battery Cathode EnergyStorage Materials Organic

Abstract

Despite revolutionizing the world of portable electronics, the contemporary lithium-ion battery (LIB) suffers from challenges associated with the cost, safety, and environmental impact of transition metal oxide-based intercalation cathodes. To alleviate these issues, naturally occurring organic molecules may serve as sustainable alternatives to traditional inorganic cathode materials. The electrochemical properties of organic compounds are derived from redox-active functional groups containing oxygen, nitrogen and sulfur. Additionally, these functional groups are capable of coordinating metal ions beyond lithium, allowing for compatibility with sodium-ion batteries (SIBs) and other earth abundant metal-based energy storage systems. However, despite competitive performance against commercialized cathode materials, much work remains to be done on organic battery systems due to their instability in common electrolytes.

The polymerization of a redox-active species has been a long-standing strategy for improving the stability of organic cathode materials. Towards this aim, a low-cost polymer of purpurin, a molecule of the quinone family, was synthesized to yield an LIB cathode material with extended cycling lifetime. Furthermore, a tetramer of the henna plant inspired lawsone molecule was elaborated in a benign aqueous solvent system. The resulting high-capacity green cathode material displayed fast-charge/discharge capabilities for SIB applications. Using analogous methodologies, a thiobarbituric acid tetramer was developed for high energy density aluminum batteries. Thereby, the advancement of greener energy storage systems was accomplished on two fronts: i) through the development of renewable cathode materials from nature-derived organic molecules, and ii) by reducing dependence on scarcity-limited lithium via next-generation batteries based on low-cost and abundant metal chemistry.

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