Abstract: 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. Our research strives to diagnose and overcome challenges related to electrochemical energy storage. We focus on mechanistic analysis that integrates both theory and experiment. In this talk, I will discuss three applications of the aforementioned research approach ranging from the molecular to the device scale. In the first, we consider the origin of pH-dependent kinetics for hydrogen evolution and oxidation. Using single-crystal voltammetry and microkinetic modeling, we find that adsorbed hydroxide is a spectator at best and a poison at worst. The implications of this finding on electrocatalyst design are discussed. In the second application, we investigate the effect of inter-electrode communication on failure mechanisms in Li-ion batteries. Electrochemical characterization of surface films using redox mediators separates transport and kinetics to determine how nominally passivating films can selectively transfer charge. These results highlight the importance of a defect-free inorganic layer for a successful interface. Finally, we apply our approach to battery electrode design. We combine rheology with electrochemical analysis to determine the role of carbon microstructure in battery performance and reach the counter-intuitive conclusion that short-range electron transport is more limiting than either long-range conductivity or tortuous ion paths.
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 in 2007 and her PhD from the University of California, Berkeley in 2012. While at Berkeley, she received a NSF Graduate Research Fellowship, an NSF East Asia Pacific Summer Fellowship, and the Daniel Cubiciotti Student Award of the Electrochemical Society. Dr. Tang completed postdoctoral work at Stanford University and research internships at Kyoto University, the University of Dortmund, and DuPont. She is the recipient of a 2018 NSF CAREER award, the 2019 College of Engineering Early Career Research Award, and a 2018 Award for Excellence in Peer Review from the ACS PRF. Her research at Drexel develops materials, architectures and fundamental insight for electrochemical energy storage and conversion.