Event Description
Maureen Tang, PhD, Chemical Engineering, Drexel University
“Materials, Methods, and Interfaces for Electrochemical Energy Storage”
In an energy landscape with increased environmental concerns and reduced availability of fossil fuels, electrochemical systems will likely play a major role for automotive and grid-storage applications. For the discovery and integration of materials that provide low-cost, long-lifetime solutions, both microscopic and macroscopic theory play an important role. Microscopic theory may predict materials with the desired behavior, while macroscopic modeling extracts critical physical and chemical properties from measurement. Successfully applying either requires experimental systems that isolate the parameter of interest. In particular, model surfaces and geometries aid in quantifying material improvements and interpreting the behavior of complicated systems. In this talk, I will discuss two applications of the aforementioned research approach. In the first, we present a theory-guided approach to design of electrocatalysts for the alkaline hydrogen electrode. Density-functional-theory calculations predict that binary silver-nickel alloys will be active for hydrogen evolution and oxidation. To circumvent the thermodynamic insolubility of these two metals and isolate catalytic activity, we employ an uncommon physical vapor codeposition synthesis. Our measurements show that the alloy is indeed more active for hydrogen evolution than pure nickel. In the second application, we investigate formation of the Solid Electrolyte Interphase (SEI), a well-known but poorly understood failure mechanism in lithium-ion batteries. We grow films on glassy carbon, a model surface, for improved experimental control, and probe the films electrochemically with a facile redox shuttle. Physics-based modeling of our results suggests that porosity, not thickness, limits through-film reaction and highlights the importance of solubility to form a successful interface.
Bio:
Maureen Tang joined the faculty of chemical and biological engineering at Drexel University in fall 2014. She received her BS in chemical engineering from Carnegie Mellon University and her PhD from the University of California, Berkeley. She has also completed postdoctoral work at Stanford University and research internships at Kyoto University, the University of Dortmund, and Dupont. Her research at Drexel develops materials, architectures, and fundamental insight for electrochemical energy storage and conversion. |
