(2cp) Interdisciplinary Research to Advance Flow-Based Electrochemical Power Systems

Approximately 60% of the energy produced in the United States is lost due to the inability of traditional thermal power sources to economically produce power from low temperature (< 100 °C) heat. My PhD research has characterized and developed thermally regenerative ammonia batteries (TRABs), which have the potential to recover low-grade waste heat, through a multidisciplinary collaborative approach. TRABs combine two-unit operations, a flow battery and a distillation column, to provide grid-scale electrochemical power and energy storage. TRABs use ammonia to create a potential difference between two otherwise identical electrolytes. The ammonia can then be separated from the spent negative electrolyte using low temperature heat to recharge the battery. My work has spanned computational modeling, experiments, and analyses across many different scales and disciplines to both advance fundamental TRAB technologies and characterize their integration with large-scale power generation systems. Through detailed multi-physics numerical simulations, I investigated the impact of electrode microstructure and advective transport on electrode current distribution and metal deposition uniformity in a porous electrode, finding that porosity and fiber arrangement play key roles in deposition patterns due to changes in the electric field and advective transport. After constructing and validating a 3D full cell model, I conducted a sensitivity analysis of three major contributions to full cell battery performance: ohmic losses, kinetics, and mass transfer. In the lab, I conducted half-cell experiments using a rotating disc electrode to show the impact of ligand concentration and temperature on reaction thermodynamics and kinetics. These results informed full cell battery experiments that provided actual power and energy density metrics to compare with commercialized battery technologies. When full cell tests showed that species diffusion was a major energy loss in TRABs, I conducted a membrane transport study to assess different methods for controlling transport in the TRAB environment. In order to assess the potential for integration into an already functional thermal power plant, I used Aspen HYSYS to model thermal energy requirements for ammonia-water separation in conjunction with real-time natural gas turbine data. My work has improved the performance of the all-aqueous copper-TRAB to produce power densities approaching those of commercially available flow batteries using inexpensive reverse osmosis membranes. Through this project, I have gained fundamental knowledge and diverse research skills pertinent to many aspects of chemical engineering that I will use to push innovative research in the lab and to bring relevant examples into course curriculum.

Throughout my undergraduate and graduate studies, I took many opportunities for leadership, mentorship, and teaching. During undergrad, I participated in and led a multidisciplinary team of engineers to design and develop a solar powered vehicle for competing in the American Solar Challenge. In undergrad and grad school, I was a teaching assistant for the senior-level Chemical Plant Design course, which I enjoyed because there is no true correct answer which forces students to consider the tradeoffs that are present in each engineering decision. As a member of multiple different lab groups in grad school and by mentoring an undergraduate researcher, I have developed soft skills for communication of complex scientific topics to non-experts in the field. In my time leading the Penn State Chemical Engineering Graduate Student Association, I organized research symposia and professional development seminars, as well as social and recruitment events and a mentorship program to help students feel welcome in our departmental community and be prepared for life after grad school. Through these experiences, I have learned how to be an effective leader in interdisciplinary teams by creating an inclusive environment in which everyone is able to grow and learn.

Research Interests

For my future work, I am interested in continuing my research on transport in electrochemical systems. Specifically, I am interested in continuing to develop novel flow battery chemistries, as well as expanding my focus to include water electrolyzers and fuel cells. Semi-solid/slurry based redox flow batteries are of keen interest due to their ability to have significantly higher energy densities than aqueous flow batteries. Expanding knowledge of transport processes in the membrane electrode assembly can improve performance due to current limitations of traditional cell architecture not being properly suited for the presence of solid particles. Water electrolyzers and fuel cells present complex transport problems due to the multiple phases present in each system, especially in electrolyzers where there is a liquid-to-gas transformation happening inside a porous electrode. Understanding of the influence of permeability of the transport layers in electrolyzers and fuel cells could be improved through numerical and experimental analysis, and my experience in microscale modeling of fluid flow with changing boundaries is well-suited to address this challenge.

Teaching Interests

Given the nature of the broad range of engineering principles present in my PhD work, I am prepared to teach many core courses in the chemical engineering curriculum. The courses that I am most interested in teaching involve transport phenomena, mathematical methods, and mass balances. Additionally, I would gladly have the opportunity to contribute my experience with electrochemical engineering or large-scale energy technologies and how the grid operates in core and elective courses.