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Early Career Lecture Series: Dr. Kent Griffith, Northwestern University

February 12, 2021 @ 11:00 am - 12:00 pm

Spring 2021 Early Career Lecture Series – Lecture 2

Dr. Kent Griffith, Postdoctoral Researcher, Department of Materials Science & Engineering, Northwestern University

Subject:

Understanding Intrinsically Rapid
Electrochemical Charge Storage in Complex Inorganic Oxides

Abstract:​ Lithium-ion batteries have enabled the portable electronics revolution of the past three decades. Looking to 2050, the sustainable energy transition will critically depend on advanced electrochemical energy storage materials – lithium-ion and beyond – to relieve our dependence on fossil fuels for transportation and grid-scale power. A limitation of conventional battery materials is their relatively slow charging rate, which is on the order of hours. While the discharge/charge rate and capacity can be tuned by varying the composite electrode structure, mixed ion–electron transport within the active electrode particles represents a fundamental chemical limitation. In this talk, I will describe how mixed-metal crystallographic shear oxides with topologically frustrated polyhedral arrangements and dense μm-scale particle morphologies can rapidly and reversibly intercalate large quantities of lithium. Multielectron redox, buffered volume expansion, in situ self-doping, and extremely fast lithium transport approaching that of a liquid can lead to high energy density and rate performance. Characterisation of these phenomena will be presented with structural and (electro-)chemical insights from operando​ X-ray diffraction and multi-edge X-ray absorption spectroscopy, high-resolution neutron diffraction, and solid-state nuclear magnetic resonance spectroscopy. The direct measurement of solid-state lithium diffusion coefficients–12 –13 (D​ ​Li)2 with–1 pulsed field gradient NMR demonstrates room temperature D​ ​Li values of 10​ –10​ m​ s​ in these complex oxides, which is several orders-of-magnitude faster than typical electrode materials and corresponds to a characteristic diffusion length of ~10 μm for a one minute charge. Materials and mechanisms that enable long-range lithiation in minutes have implications for high-power, fast-charging devices and for broader approaches to electrode design and material discovery.

 

Biography:​ Kent Griffith is a postdoctoral research scientist at Northwestern University in the

Department of Materials Science and Engineering and the Department of Chemistry where he is investigating new materials for energy storage and conversion with Professors G. Jeffrey Snyder and Ken Poeppelmeier. He earned his PhD in Chemistry with Professor Clare Grey at the University of Cambridge on a Churchill Scholarship. His work focuses on the synthesis and advanced characterization of state-of-the-art and next-generation battery materials with solid-state NMR spectroscopy, synchrotron and neutron diffraction, high-energy X-ray spectroscopy, DFT calculations, and electrochemical techniques.

Kent has 36 peer-reviewed scientific publications and has presented his work at over 40 international academic and industry conferences. He has also been recognized with awards including the Charles Hatchett Award from the Institute of Materials, Minerals, and Mining; the Sheelagh Campbell Electrochemistry Award from the Royal Society of Chemistry; the Futures Early Career Award from the UK Science and Technology Facilities Council (STFC); and the Barry M. Goldwater Scholarship established by the United States Congress.

 

 

      

 

 

 

Details

Date:
February 12, 2021
Time:
11:00 am - 12:00 pm
Event Category:

Venue

EB1 – Room 1011
911 Partners Way
Raleigh, NC 27695-7907 United States

Organizer

MSE Department
Phone
919.515.2377
View Organizer Website

Other

Speaker
Dr. Ken Griffith
Host
Dr. Veronica Augustyn