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Charge transport in nonstoichiometric 2-fluoropyridinium triflate protic ionic liquids

Jannasch, Patric LU ; Rehmen, Junaiz ; Evans, Drew and Karlsson, Christoffer LU (2019) In Journal of Physical Chemistry C 123(38). p.23427-23432
Abstract
Pyridinium triflate protic ionic liquids have been demonstrated to be highly dissociated, and nonstoichiometric compositions have been used in protic energy devices such as the all-organic proton battery. Herein, we use a combination of pulsed field gradient NMR spectroscopy and electrochemical impedance spectroscopy to investigate the charge transport properties of the nonstoichiometric protic ionic liquid 2-fluoropyridinium triflate and the variation with acid doping level. While all diffusion coefficients decreased with the amount of acid doping, the room temperature conductivity increased due to the concurrent increase in charge carrier concentration. The maximum room temperature conductivity was 7.33 mS/cm, obtained when 14% of the... (More)
Pyridinium triflate protic ionic liquids have been demonstrated to be highly dissociated, and nonstoichiometric compositions have been used in protic energy devices such as the all-organic proton battery. Herein, we use a combination of pulsed field gradient NMR spectroscopy and electrochemical impedance spectroscopy to investigate the charge transport properties of the nonstoichiometric protic ionic liquid 2-fluoropyridinium triflate and the variation with acid doping level. While all diffusion coefficients decreased with the amount of acid doping, the room temperature conductivity increased due to the concurrent increase in charge carrier concentration. The maximum room temperature conductivity was 7.33 mS/cm, obtained when 14% of the pyridine was protonated with triflic acid, while higher acid doping levels lead to liquid/solid mixtures with low conductivity. PEDOT supercapacitor cells with this electrolyte demonstrated very high capacitance (83.9 F/g) and charge storage capacity (23.3 mAh/g). In addition we predict that using a lower acid doping level than previously will result in superior electrolyte performance in proton batteries due to improvements in conductivity, processability and electrochemical stability. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry C
volume
123
issue
38
pages
23427 - 23432
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85073004174
ISSN
1932-7447
DOI
10.1021/acs.jpcc.9b07923
language
English
LU publication?
yes
id
61262395-160c-497b-8932-d9b68dc87744
date added to LUP
2019-09-02 16:50:08
date last changed
2020-01-13 02:19:08
@article{61262395-160c-497b-8932-d9b68dc87744,
  abstract     = {Pyridinium triflate protic ionic liquids have been demonstrated to be highly dissociated, and nonstoichiometric compositions have been used in protic energy devices such as the all-organic proton battery. Herein, we use a combination of pulsed field gradient NMR spectroscopy and electrochemical impedance spectroscopy to investigate the charge transport properties of the nonstoichiometric protic ionic liquid 2-fluoropyridinium triflate and the variation with acid doping level. While all diffusion coefficients decreased with the amount of acid doping, the room temperature conductivity increased due to the concurrent increase in charge carrier concentration. The maximum room temperature conductivity was 7.33 mS/cm, obtained when 14% of the pyridine was protonated with triflic acid, while higher acid doping levels lead to liquid/solid mixtures with low conductivity. PEDOT supercapacitor cells with this electrolyte demonstrated very high capacitance (83.9 F/g) and charge storage capacity (23.3 mAh/g). In addition we predict that using a lower acid doping level than previously will result in superior electrolyte performance in proton batteries due to improvements in conductivity, processability and electrochemical stability.},
  author       = {Jannasch, Patric and Rehmen, Junaiz and Evans, Drew and Karlsson, Christoffer},
  issn         = {1932-7447},
  language     = {eng},
  number       = {38},
  pages        = {23427--23432},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Journal of Physical Chemistry C},
  title        = {Charge transport in nonstoichiometric 2-fluoropyridinium triflate protic ionic liquids},
  url          = {http://dx.doi.org/10.1021/acs.jpcc.9b07923},
  doi          = {10.1021/acs.jpcc.9b07923},
  volume       = {123},
  year         = {2019},
}