NMR transport studies of liquid redox-active organic materials
Analytical Chemistry
Final Report Abstract
This project dealt with the characterization of liquid redox active organic materials (L-ROMs) by means of NMR spectroscopy. L-ROMs are materials that can be electrically charged use in batteries. They differ from conventional lithium-ion batteries in that L-ROMs are liquid instead of solid, and that they can be produced from non-critical raw materials. Due to their liquid aggregate state, L-ROMs possess high charge density and flexible application possibilities, especially for local energy storage in municipalities and cities. In combination with a conducting salt and a diluent L-ROMs form a complex system that is currently poorly understood and optimized. An important property of these systems is ion mobility and charge transport, which significantly determine its efficiency and performance. NMR spectroscopy is a versatile analytical method that can be used to determine the mobility of molecules and ions. Therefore, this technique was used in the project to determine the property of lithiumion mobility in two L-ROM systems as well as their interactions with other components. To put in a nutshell, it was found in this research that, for the two L-ROM systems investigated, lithium i) has an atypically low mobility and ii) does not diffuse freely, but instead forms ion pairs with correspondingly negatively charged ions in solution.
