[CCoE Notice] Dissertation Defense: Design, synthesis and characterization of quinone electrode materials fro sustainable energy storage

[Grayson, Audrey A]

Dissertation title: Design, synthesis and characterization of quinone electrode materials fro sustainable energy storage

Committee chair: Prof. Yan Yao

Date: Friday, July 14th 10:00 am-12:00 pm

Location: ECE Large conference room, N308 Cullen College of Engineering Bldg 1

Abstract: The energy crisis and environmental issues have instigated the integration of
renewable energy sources into the electric grid. A robust, safe, low-cost, and long-life energy
storage system is therefore strongly desired to maximize the benefits of intermittent
renewable resources. Organic electrode materials, such as quinones, have recently attracted
significant attention due to their high capacity, low-cost, environmental friendliness, and
ability to be derived from biomass. The objective of this dissertation is to design, synthesize,
and characterize multiple quinone-based electrode materials in aqueous and non-aqueous
electrolytes for building next-generation energy storage technologies. My aim is to better
understand the complex interactions among redox molecules/oligomers, ions, electrons, and
electrolytes, and find ways to design better materials with improved performance.
        In this dissertation, I report the design, synthesis, and characterization of quinonebased
oligomers and corresponding electrochemical properties in aqueous and non-aqueous
electrolytes. I first report the synthesis of two cross-conjugated quinone oligomers and the
effects of cross-conjugation and molecular conformations on the electrochemical properties. I
further investigate the oligomers in aqueous electrolytes and discover the maximum capacity
can be realized when the pH of electrolyte is above the pKa of the reduced quinones. Third, I
discover that a sufficient swelling for the polyquinone film may be imperative to release full
capacity. The combination of electrochemical quartz crystal microbalance and constant
current charge-discharge techniques reveal that hydrated cations serve as charge carriers in
aqueous electrolytes, and that the hydration numbers dynamically vary with the state of
charge and current density. Finally, an oligomer based on pyrene-4,5,9,10-tetraone core with
4-electron reduction was synthesized and characterized in various electrolytes (H+, Li+, Na+,
and Mg2+ over a pH range of 0-13). A Pourbaix diagram was then derived to understand the
competition between H+ and metal-ion coordination. The work described in this dissertation
strives to provide an in-depth understanding of the working mechanisms of quinone-based
electrodes and guidelines for future organic battery development.

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