Speaker
Description
Lithium fluoride, known to be a very poor ionic conductor, was chosen as a model substance to investigate the influence of the insulator TiO2 on ion dynamics in LiF. In general, in such two-phase systems percolating Li pathways at the conductor | insulator interface may lead to enhanced ion dynamics. Indeed, we observed such an effect which we investigated by impedance spectroscopy and Nuclear Magnetic Resonance (NMR). Compared to nanocrystalline LiF, an increase in (total) conductivity of nearly four orders of magnitude, that is, from 6 · 10-11 S cm-1 up to 2 · 10-7 S cm-1 (100°C) was observed by adding 40vol% TiO2. As both ions in LiF, Li and F, are mobile, NMR helped reveal Li+ as the mainly responsible ion for this increase. Compared to SiO2 and Al2O3 [1], TiO2 revealed the largest increase in conductivity making it highly suitable to effectively engineer the interfacial regions in such conductor|insulator systems.
[1] S. Breuer, V. Pregartner, S. Lunghammer and H. M. R. Wilkening, J. Phys. Chem. C 2019, 123, 9, 5222–5230
| Speaker Country | Austria |
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