<p>This thesis evaluates several solid-state NMR spectroscopy approaches to studying lithium ion dynamics in solid-state electrolytes. With the goal of reducing the risks associated with current liquid electrolytes, solid-state electrolytes provide non-flammable materials that are also stable against attack by cathode and anode materials. Solid-state NMR spectroscopy offers a versatile method to determine structural details and can also provide information about ion mobility in solid-state electrolytes. Challenges involved in the study of solid-state electrolytes include the difficulty in distinguishing between <sup>6,7</sup>Li resonances due to the small chemical shift range of diamagnetic lithium species. The NMR methods selected in this thesis aim to circumvent some of these issues in order to determine structural and dynamic properties in solid-state electrolytes. Several different electrolytes have been examined including LaLi<sub>0.5</sub>Fe<sub>0.2</sub>O<sub>2.09</sub> and related materials, which exhibit intricate structural properties. <sup>139</sup>La NMR spectroscopy, in combination with <sup>7</sup>Li MAS NMR spectroscopy, was used to determine the nature of this disorder. In addition, studies of the quadrupolar framework <sup>87</sup>Rb nucleus, which take advantage of its large electric field gradient, have been used to indirectly probe the activation energy for Ag<sup>+</sup> ion hopping in the solid-state silver ion electrolyte RbAg<sub>4</sub>I<sub>5</sub>. Alternatively, dipolar coupling between <sup>6</sup>Li and <sup>7</sup>Li has been used to compare lithium ion hopping rates in Li<sub>6</sub>BaLa<sub>2</sub>M<sub>2</sub>O<sub>12</sub> (M = Ta, Nb) using <sup>6</sup>Li{<sup>7</sup>Li}-REDOR NMR studies. Finally, T<sub>2</sub> relaxation studies have been used to probe ion dynamics in Li<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> and LiVO<sub>3</sub> in order to determine if this is a viable method to study dynamics in these materials.</p> / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/13799 |
| Date | 04 1900 |
| Creators | Spencer, Noakes L Tara |
| Contributors | Goward, Gillian, Mozharivskyj, Yurij, Chemistry |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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