Development of magnetic resonance methodologies for battery investigation

Doswell, Claire Linda ORCID: 0000-0002-9680-9669 (2022). Development of magnetic resonance methodologies for battery investigation. University of Birmingham. Ph.D.

Preview

Doswell2022PhD.pdf
Text - Accepted Version
Available under License All rights reserved.
Download (8MB) | Preview

Abstract

In this thesis, magnetic resonance (MR) methods are developed to examine battery chemistries. A method to increase the signal-to-noise ratio (SNR) without increasing experimental time is developed. Furthermore, sodium and lithium batteries are investigated using nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). Additionally, the speciation in electrolytes for aluminium batteries is investigated using NMR spectroscopy.

In Chapter 3, MRI methodology is developed to increase the SNR to enable quantitative T\(_1\) relaxation time maps without an increase in acquisition time. The increased SNR allows the visualisation of water ingress into an ionic liquid (IL) containing a zinc salt, Zn(TfO) in 1-ethyl-3 methylimidazolium triflate (C\(_2\)C\(_1\)imTfO) over time. A change in the zinc speciation is determined from a plot of \(^{19}\)F T\(_1\) NMR relaxation time versus water concentration.

In Chapter 4, operando \(^{23}\)Na NMR and MRI methodology is developed to visualise battery chemistry. \(^{23}\)Na NMR spectroscopy is used to establish changes in the sodium species present during the formation cycle of a cell. This is applied to a sodium metal cell, where the speciation changes in the electrolyte are observed, and a sodium full cell, where the development of quasimetallic nanoparticles and a metallic species are observed during the formation cycle for the first time. This methodology is used in Chapter 5 with \(^7\)Li NMR spectroscopy and MRI to observe the changes in the lithium metal electrode and electrolyte species in a lithium metal cell during the formation cycle.

In Chapter 6, aluminium battery chemistries are explored using \(^1\)H and \(^{27}\)Al NMR spectroscopy. The speciation and molecular interactions in an aluminium IL, 1-butyl-3-methlyimidazolium chloride (C\(_4\)C\(_1\)imCl) containing AlCl\(_3\) and water, is investigated. \(^{27}\)Al NMR spectroscopy is used to investigate the speciation changes in the IL with respect to AlCl\(_3\) concentration. \(^1\)H NMR spectroscopy, combined with \(^{27}\)Al NMR spectroscopy is used to suggest hydrogen bonding interactions within the IL. \(^1\)H T\(_1\) and T\(_2\) NMR relaxation times with respect to AlCl\(_3\) concentration are explored, demonstrating possible utility as MRI contrast. The intermolecular interactions and relaxation times of \(^{27}\)Al and \(^1\)H species are investigated in a potential aqueous aluminium battery electrolyte, AlCl\(_3\) in saltwater. The \(^1\)H T\(_1\) NMR relaxation time is shown to provide suitable contrast for MRI of AlCl\(_3\) in saltwater.

The methods developed in this thesis are applicable across multiple nuclei and address some of the issues surrounding poor SNR in the use of NMR active nuclei with low gyromagnetic ratios and rapid NMR relaxation times. This thesis demonstrates how data from NMR spectroscopy and MRI can be combined to develop a more holistic understanding of battery chemistry.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):