Cain Department of Chemical Engineering SEMINAR

 

“Understanding and Controlling Electrochemistry for Fuel Cells and Batteries”

Andrew A. Gewirth
Department of Chemistry
University of Illinois – Urbana-Champaign

This talk addresses both the Oxygen Reduction Reaction (ORR) – a central reaction important in fuel cells and reactivity associated with battery electrodes.  In the former, we develop design rules for effective new ORR catalysts and actualize these by synthesizing and characterizing Cu- and Fe-based catalysts for this reaction.  We show that ligands which are effective to make good ORR catalysts also have a positive role in other chemistries, particularly those involving CO₂ reduction and the oxygen evolution reaction.  Finally, we develop a new platform to more generally address proton-coupled electron transfer (PCET) reactions, of which the ORR is one.

Relevant to batteries, we present a new technique to probe the electrochemically-induced mechanics of electrodes by calculating the electrochemical stiffness of electrodes via coordinated in situ stress and strain measurements.  Through the electrochemical stiffness, we elucidate inherent and rate-dependent mechanical responses of graphitic and LMO-based battery electrodes. We find that stress and strain are asynchronous.  Electrochemical stiffness measurements provide new insights into the origin of the rate-dependent chemo-mechanical degradations, and provide a probe to evaluate advanced battery electrodes.

Friday, April 6, 2018
2:00 PM
1240 Patrick F. Taylor Hall