Investigation of Transverse Relaxation Rate Distribution via Magnetic Resonance Imaging: Impact of Electrode Formation. Issue 6 (23rd September 2020)

• Record Type: Journal Article
• Authors: Balbierer, Roland; Seegert, Philipp; Herberger, Sabrina; Wetzel, Thomas; Nirschl, Hermann; Guthausen, Gisela
• Other Names: Wetzel Thomas guestEditor.; Bessler Wolfgang G. guestEditor.; Kamlah Marc guestEditor.; Nirschl Hermann guestEditor.
• Is Part Of: Energy technology. Volume 9:Issue 6(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-23
• Subjects: electrochemistry -- ion concentration distributions -- lithium-ion batteries -- nuclear magnetic resonance -- solid electrolyte interfaces; Energy development -- Periodicals; Power resources -- Periodicals; 333.79
• DOI: 10.1002/ente.202000579
• Languages: English
• ISSNs: 2194-4288

Abstract

Abstract : The impact of electrode formation is studied by the spatially and time‐resolved distribution of transverse relaxation. In situ 7 Li nuclear magnetic resonance experiments are performed on an experimental lithium‐ion battery cell to study the impact of electrode passivation via imaging and transverse relaxation in the interelectrode volume. The electrolyte in the battery, using technically relevant electrode material, i.e., graphite and lithium–nickel–cobalt–manganese–oxide, is studied by 2D magnetic resonance imaging. The electrolyte is 1 mol L −1 lithium hexafluorophosphate dissolved in a binary mixture of ethylene carbonate and dimethyl carbonate. 1D profiles are acquired and related to 7 Li concentration during passivation and during a constant current/constant voltage cycle. The transverse relaxation rate R 2 ( z, t ) measured by multiecho profiles revealed changes within the electrolyte volume. The ongoing process changes the relaxation distribution. Indications for a defective electrode passivation are deduced from the data. During one charging cycle with constant current/constant voltage, the lithium concentration is measured spatially resolved, and the data are modeled by the Nernst–Planck equation. Abstract : The composition of the solid electrolyte interface is one of the key factors of battery stability and long‐life durability. This novel approach studies the impact of formation by investigating the transverse relaxation rate distribution R 2 ( z, t ) spatially and time‐resolved. Defective electrode passivation processes are addressed by quantifying the change in relaxation rate in combination with monitoring the cell voltage.