Mar 16, 2016 – NMR Topical Group Meeting

Abstract

MRI is a useful tool for studying electrochemical systems because it can be applied to functioning devices in situ and can resolve chemical and spatial informational about components in different phases of matter. I will present our recent work that exploits these advantages of MRI in order to study the growth of dendrites in functioning lithium metal batteries.

Dendrite growth is a serious problem that leads to performance degradation as well as severe safety concerns in rechargeable lithium-ion batteries, and understanding the working conditions under which they form and continue to grow is crucial. By performing ⁷Li MRI on both the electrolyte and lithium metal electrodes in a functioning lithium metal battery, we have been able to correlate the behavior of the electrolyte concentration gradient to the type and rate of dendrite growth on the surface of the Li electrode, confirming the existence of separate growth mechanisms in different charging regimes.

Due to the rf skin effect, the ⁷Li metal signal is particularly sensitive to changes at the surface of the electrode. However, the short T₂ and low SNR prevent the collection of high-resolution, 3D ⁷Li images of the dendrites. Instead, we have developed methodology using ¹H FLASH imaging to indirectly observe dendritic structures via their impact on the detected signal intensity of the organic electrolyte components. This approach is supported by robust calculation methods that reconstruct the susceptibility and rf field inhomogeneities around the metallic microstructures. The result is a real-time, 3D movie showing dendrites growing across the electrodes in the cell, shedding light on the growth rate and morphology of the structures formed.

Times

6:00 pm   Dinner
7:00 pm  Seminar

Venue

Frick Chemistry Atrium (dinner)
Frick Chemistry Room A81 (seminar),
Princeton University. [ Directions ]

Dinner Cost:

Dinner cost: $15 employed / $5 students, postdoc, retired, unemployed — payable at the door
No charge for seminar only.

Questions:

frank.rinaldi@bms.com or Anuji.Abraham@bms.com

Parking:

Parking will be available in Lot21 (see map link given above under Directions)

Public Transit:

It is possible to take NJ Transit all the way to Princeton campus (the symposium location is ~ 10 min walk from the train station). Take the Northeast Corridor NJ transit train to Princeton Junction, then transfer to the small “dinky” train that ends on campus (5 min train ride).

Register:

Please register online here or via e-mail to frank.rinaldi@bms.com