Date: March 9, 2015
Time: 4:30 p.m. - 6:00 p.m.
Location: Computer Science, Room 105
Professor Clare Grey, of the University of Cambridge, presents “In-situ Studies of Batteries and Supercapacitors: What can we Learn?” as part of the Andlinger Center’s 2014-2015 Highlight Seminar Series.
ABSTRACT
Cheaper and more efficient/effective ways to convert and store energy are required to reduce CO2 emissions. Batteries, supercapacitors and fuel cells will play an important role, but significant advances require that we understand how these devices operate over a wide range of time and lengthscales, particularly under operating conditions (i.e., in-situ). To this end, our recent applications of new in and ex-situ Nuclear Magnetic Resonance (NMR) and X-ray diffraction (XRD) approaches to correlate structure and dynamics with function, in lithium-ion batteries and supercapacitors, will be described. The in-situ approach allows processes to be captured, which are very difficult to detect directly by ex-situ methods. For example, we can detect side reactions involving the electrolyte and electrode materials, solid-liquid interfacial structures, and non-equilibrium processes that can occur during extremely fast charging and discharging. Complementary Ex-situ NMR investigations allow more detailed structural studies to be performed, to correlate local and long-range structure with performance.
After a general overview of our in situ NMR and MRI studies on batteries and supercapacitors, this talk will focus on our recent work on olivines, spinels and Ge/Si anodes. For olivines, we show how the use of fast charging and optimized cell designs for use at synchrotron facilities allows us to capture metastable/non-equilibrium states.(1) Mapping of the electrodes using micro-diffraction allows the distribution of the reaction front across the electrode to be followed. Second, the development of new NMR approaches to investigate paramagnetic battery materials, both in and ex situ, will be discussed, the approach making use of both theory and experiment. Although it is difficult to achieve high-resolution spectra from these paramagnetic materials in the in situ experiments, measurements of the relaxation time allow access to the dynamics of the lithium ions in real time as a function of state of charge.(2) Finally, the use of pair distribution function analysis of diffraction data and NMR spectroscopy, in the study of disordered and amorphous anode materials will be described,(3) the talk ending with some perspectives on future (“beyond-Li”) battery technologies.
(1) H. Liu et al. Science, 344, no 6191 DOI: 10.1126/science.1252817 (2014).
(2) L. Zhou et al. J. Mag. Res., 234, 44-57 (2013).
(3) H. Jung et al. Chem. Mater. DOI: 10.1021/cm504312x (2014).
BIO
Clare P. Grey is the Geoffrey Moorhouse-Gibson Professor of Chemistry at Cambridge University. She received a B.A. and D.Phil. (1991) in Chemistry from the University of Oxford. After spending a year as a Royal Society post-doctoral Fellow at Nijmegen University and two years as a visiting scientist at DuPont CR&D in Wilmington, DE (1992–1993) she joined the faculty at Stony Brook University (SBU) as an Assistant (1994), Associate (1997) and then Full Professor (2001). She moved to Cambridge in 2009, maintaining a part-time position at SBU. She was the director of the Northeastern Chemical Energy Storage Center, a Department of Energy, Energy Frontier Research Center (2009-2010) and associate director (2011-2014). Her recent honors and awards include the 2007 Research Award of the Battery Division of the Electrochemical Chemical Society, the 2010 Ampere and RSC John Jeyes Awards, the 2011 Royal Society Kavli Lecture and Medal for work relating to the Environment/Energy, Honorary Ph.D. Degrees from the Universities of Orleans (2012) and Lancaster (2013), the Gunther Laukien Award from the Experimental NMR Conference (2013), the Research Award from the International Battery Association (2013) and the Royal Society Davy Award (2014). She is a Fellow of the Royal Society. Her current research interests include the use of solid state NMR and diffraction-based methods to determine structure-function relationships in materials for energy storage (batteries and supercapacitors), conversion (fuel cells) and carbon capture.