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We report the results of atomistic molecular dynamics simulations on polymerized 1-butyl-3-vinylimidazolium-hexafluorophosphate ionic liquids, studying the influence of the polymer molecular weight on the ion mobilities and the mechanisms underlying ion transport, including ion-association dynamics, ion hopping, and ion–polymer coordinations. With an increase in polymer molecular weight, the diffusivity of the hexafluorophosphate (PF 6 − ) counterion decreases and plateaus above seven repeat units. The diffusivity is seen to correlate well with the ion-association structural relaxation time for pure ionic liquids, but becomes more correlated with ion-association lifetimes for larger molecular weight polymers. By analyzing the diffusivity of ions based on coordination structure, we unearth a transport mechanism in which the PF 6 − moves by “climbing the ladder” while associated with four polymeric cations from two different polymers.
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Ionic conduction mechanism in high concentration lithium ion electrolytes
The conduction mechanism of a family of high concentration lithium electrolytes (HCEs) is investigated. It is found in all HCEs that the molecular motions are regulated by the anion size and correlated to the HCE ionic resistivity. From the results, a mechanism involving highly correlated ionic networks is derived.
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- Award ID(s):
- 1751735
- PAR ID:
- 10414254
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 59
- Issue:
- 13
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 1849 to 1852
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D2CC05645C
