Distinguished seminar: «Understanding Redox Flow Batteries and Ammonia Synthesis via Operando NMR Methods»

Summary

Understanding Redox Flow Batteries and Ammonia Synthesis via Operando NMR Methods

Evan Wenbo Zhao, Magnetic Resonance Research Center, Institute for Molecules and Materials, Radboud University Nijmegen, the Netherlands

Electrochemical energy storage and conversion are effective solutions to decarbonize our industry and society. Among the available energy technologies, we are interested in redox flow batteries and electrochemical synthesis of liquid fuels – the former is suited for storage on the timescale of hours and the latter can be used for seasonal storage. The broad implementation of these technologies requires fundamental understanding of the electrochemistry occurring inside the working devices.

For the first part of my talk, I will present how we develop and apply new operando nuclear magnetic resonance (NMR) methods to unravel rich electrochemistry in an anthraquinone-based redox flow battery. I will discuss how the operando NMR methods allow us to identify and quantify reaction intermediates, degradation products and intermolecular electron transfer. Leveraging on these understandings, we discovered a simple electrochemical method to prolong the battery lifetime up to seventeen times. Next, I will present an operando NMR study of Li-mediated ammonia synthesis.  Lithium metal deposition, dissolution and morphological changes were captured during the reaction. Solvent and electrolyte effect on these processes were investigated. I will finally discuss the implications on the Faradaic efficiency and rate for this reaction.

Short Bio

Evan Wenbo Zhao is a tenured assistant professor at the Magnetic Resonance Research Center at Radboud University Nijmegen in the Netherlands. He did his postdoc with Prof. Clare Grey at the Yusuf Hamied Department of Chemistry at the University of Cambridge. He earned his PhD degree in Chemistry with Prof. Clifford Russell Bowers at the University of Florida and his bachelor degree from Nanyang Technological University. Evan has published 26 papers in Nature, Nature Materials, Nature Chemistry, Nature Communications, Chem, JACS, Angew. Chem. etc.