Prof. Steve G. Greenbaum (Hunter College Of The City University Of New York) Thursday 23rd May 2019, 11:30 Institute Of Macromolecular Chemistry CAS Heyrovského Nám. 2, Prague 6

Our laboratory is focused on application of various nuclear magnetic resonance (NMR) techniques to help understand structure and dynamics of energy storage materials, in particular novel electrolytes. In this presentation we discuss three recent collaborative efforts. (i) The first topic, in collaboration with Oak Ridge National Lab (R. Ruther, J. Nanda), is on low molecular mass polyethers (i.e.glyme) -based electrolytes being developed for lithium metal and Na ion batteries as well as electrolytic double layer capacitors. Though electrochemically more stable than the carbonates, NMR and vibrational spectroscopic measurements show that significant ion pairing is evident in these electrolytes. (ii) In collaboration with UCLA (B. Dunn, D. Ashby), we have investigated ionogels, which are pseudo-solid-state electrolytes consisting of the IL BMIM TFSI plus LiTFSI salt electrolyte confined in a mesoporous inorganic matrix. We report here NMR measurements of ionic self-diffusion coefficients as well as broadband relaxometry with emphasis on elucidating confinement effects of the silica matrix on ionic transport. (iii)  With Ionic Materials, Inc. (M. Zimmerman, R. Leising), we discuss results for a solid polymeric electrolyte based on semicrystalline polyphenylene sulfide and LiTFSI. This polymer electrolyte can be reliably extruded into thin films, is non-flammable, has attractive mechanical properties for lithium dendrite suppression, is electrochemically stable against Li, and is compatible with a variety of different cathodes, including NMC811. NMR diffusometry measurements reveal Li room temperature self-diffusion coefficients that are the highest in any known solid.

Prof. Steve Greenbaum is CUNY Distinguished Professor of Physics at Hunter College (New York) and a Fellow of the American Physical Society. He earned his PhD in Physics from Brown University, was a postdoc in the Semiconductors Branch at the U.S. Naval Research Laboratory and spent sabbatical years as a Fulbright Scholar at the Weizmann Institute and Senior Fellow at the Jet Propulsion Laboratory, where he was a member of the team that designed the lithium ion batteries for the successful Mars Rover missions. He was Visiting Professor at several universities including Stony Brook, Rutgers, Tel Aviv, Paris-Sud, Padova, and Rome Sapienza. Dr. Greenbaum studies disordered solids by magnetic resonance and synchrotron x-ray absorption, and has co-authored over 270 peer-reviewed publications. He was a Jefferson Science Fellow at the U.S. State Department in 2014-15.

Registration: free, please, register by sending email to Petr Šálek (salek@imc.cas.cz).