Master of Science, The Ohio State University, 2024, Chemistry

With sustainable energy storage at the forefront of global concerns, the development of high-performance, long-lasting battery systems is of paramount importance. The first chapter of this thesis explores polymerization techniques for synthesizing tetrazine-based polymers as sustainable cathode materials for aqueous Zn-ion batteries. Understanding the impact of polymerization on tetrazine electrode materials has interesting implications for the overall adoption of the tetrazine motif in energy storage. The second chapter of this thesis investigates the incorporation of nitrogen oxide gases in Na batteries. The incorporation of these gases promises to surpass cell potentials and reversibility seen in conventional Na-O2 or Na-CO2 batteries. By harnessing the unique properties of nitrogen oxides, this research aims to markedly enhance battery energy output, contributing to the advancement of sustainable energy technologies.

Committee: Yiying Wu (Committee Member); Shiyu Zhang (Advisor) Subjects: Chemical Engineering; Chemistry; Energy

Doctor of Philosophy, The Ohio State University, 2022, Chemistry

The ability to store energy in a scalable, profitable, and environmentally benign manner is a key challenge in the global transition to clean energy. Unfortunately, lithium-ion batteries (LIBs) and other conventional energy storage systems depend on metal-based electrode materials and the large-scale mining of metal ores, which is environmentally costly and ultimately unsustainable. Organic electrode materials (OEMs) offer an intriguing alternative to metal-based electrode materials, as OEMs benefit from abundant feedstocks, unparalleled synthetic modularity, and rich redox chemistry. However, reported OEMs lack the fast charging rates and long cycle lifetimes of metal-based electrode materials, likely due to low electrical conductivity and dissolution in battery electrolytes. To address these issues, we have focused on understanding fundamental relationships between the molecular structure of OEMs and battery performance, which can serve as design guidelines for the development of next-generation sustainable energy storage systems. Using benzoquinone as our OEM scaffold, we first investigated the impact of discrete synthetic modifications, such as incorporating thiazyl (-S=N-) moieties or hydrogen bonding motifs, to uncover new structure-performance trends for OEMs in LIBs. Through theoretical calculations and experimental studies, we established a positive correlation between non-covalent intermolecular interaction strength and performance for thiazyl and hydrogen bonding functional groups. In particular, we found that increasing the number of thiazyl S atoms or hydrogen bonding groups leads to stronger intermolecular interactions, resulting in enhanced charging rates and prolonged battery lifetimes. These works showcase molecular modification as a tool for systematically tuning battery performance, presenting two possible design strategies for improving conductivity and stability in future OEMs. Aside from LIBs, aqueous Zn-ion batteries (AZIBs) have become (open full item for complete abstract)

Committee: Shiyu Zhang (Advisor); Yiying Wu (Committee Member); Christopher Hadad (Committee Member); Christo Sevov (Committee Member) Subjects: Chemistry; Inorganic Chemistry; Organic Chemistry