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Probing ion exchange in the triflic acid-guanidinium triflate system: A solid-state nuclear magnetic resonance study

journal contribution
posted on 11.12.2014, 00:00 authored by Haijin Zhu, D Macfarlane, Maria ForsythMaria Forsyth
Knowledge of ion exchange and transport behavior in electrolyte materials is crucial for designing and developing novel electrolytes for electrochemical device applications such as fuel cells or batteries. In the present study, we show that, upon the addition of triflic acid (HTf) to the guanidinium triflate (GTf) solid-state matrix, several orders of magnitude enhancement in the proton conductivity can be achieved. The static 1H and 19F solid-state NMR results show that the addition of HTf has no apparent effect on local molecular mobility of the GTf matrix at room temperature. At higher temperatures, however, the HTf exhibits fast ion exchange with the GTf matrix. The exchange rate, as quantified by our continuum T2 fitting analysis, increases with increasing temperature. The activation energy for the chemical exchange process was estimated to be 58.4 kJ/mol. It is anticipated that the solid-state NMR techniques used in this study may be also applied to other organic solid-state electrolyte systems to investigate their ion-exchange processes.

History

Journal

Journal of Physical Chemistry C

Volume

118

Issue

49

Pagination

28520 - 28526

Publisher

American Chemical Society

Location

Washington, D.C.

ISSN

1932-7447

eISSN

1932-7455

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2014, American Chemical Society