Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Jul 1;6(7):4306-4310.
doi: 10.1039/c5sc01398d. Epub 2015 May 5.

Low temperature ionic conductor: ionic liquid incorporated within a metal-organic framework

Kazuyuki Fujie  1   2 , Kazuya Otsubo  2 , Ryuichi Ikeda  2   3 , Teppei Yamada  2 , Hiroshi Kitagawa  2   4   5   6
Affiliations

Low temperature ionic conductor: ionic liquid incorporated within a metal-organic framework

Kazuyuki Fujie et al. Chem Sci. .

Abstract

Ionic liquids (ILs) show promise as safe electrolytes for electrochemical devices. However, the conductivity of ILs decreases markedly at low temperatures because of strong interactions arising between the component ions. Metal-organic frameworks (MOFs) are appropriate microporous host materials that can control the dynamics of ILs via the nanosizing of ILs and tunable interactions of MOFs with the guest ILs. Here, for the first time, we report on the ionic conductivity of an IL incorporated within a MOF. The system studied consisted of EMI-TFSA (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide) and ZIF-8 (Zn(MeIM)2, H(MeIM) = 2-methylimidazole) as the IL and the MOF, respectively. While the ionic conductivity of bulk EMI-TFSA showed a sharp decrease arising from freezing, the EMI-TFSA@ZIF-8 showed no marked decrease because there was no phase transition. The ionic conductivity of EMI-TFSA@ZIF-8 was higher than that of bulk EMI-TFSA below 250 K. This result points towards a novel method by which to design electrolytes for electrochemical devices such as batteries that can operate at low temperatures.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1. XRPD patterns of ZIF-8, EZ25, EZ50, EZ75, and EZ100. The plane indices were assigned with reference to a previous report.
Fig. 2
Fig. 2. Model crystal structure (a) and an EMI-TFSA ion pair inside the pore (b) of EZ25 based on the Rietveld refinement in the bulk state. In both panels, one pair of EMI+ and TFSA– extracted from disordered components is shown for clarity. In panel (a), included EMI-TFSA units are drawn as the stick model with superimposed CPK model. Zinc, carbon, nitrogen, oxygen, fluorine, sulfur and hydrogen atoms are shown in orange, grey, blue, red, green, yellow, and pink, respectively.
Fig. 3
Fig. 3. Nitrogen gas adsorption and desorption isotherms of ZIF-8 (green), EZ25 (red), and EZ50 (blue) at 77 K. The open and closed symbols indicate adsorption and desorption, respectively.
Fig. 4
Fig. 4. DSC curves of EZ25, EZ50, EZ75, EZ100, EZ125, and bulk EMI-TFSA. The red and blue lines indicate heating and cooling, respectively, at a fixed scan rate of 5 K min–1.
Fig. 5
Fig. 5. Arrhenius plots of the ionic conductivity of EZ50, EZ75, EZ100, EZ125, and bulk EMI-TFSA on heating. The solid lines are provided as guides for the eye.
Fig. 6
Fig. 6. Solid-state 19F static NMR spectra of EZ50, EZ75, EZ100, and bulk EMI-TFSA at ambient temperature.
See this image and copyright information in PMC

References

    1. Pasquier A. D., Plitz I., Menocal S., Amatucci G. J. Power Sources. 2003;115:171.
    1. Ding M. S., Xu K., Jow T. R. J. Electrochem. Soc. 2000;147:1688.
    2. Smart M. C., Ratnakumar B. V., Surampudi S. J. Electrochem. Soc. 1999;146:486.
    3. Xu K. Chem. Rev. 2004;104:4303. - PubMed
    1. Wang P., Zakeeruddin S. M., Comte P., Exnar I., Grätzel M. J. Am. Chem. Soc. 2003;125:1166. - PubMed
    2. Ue M., Takeda M., Toriumi A., Kominato A., Hagiwara R., Ito Y. J. Electrochem. Soc. 2003;150:A499.
    3. Souza R. F., Padilha J. C., Gonçalves R. S., Dupont J. Electrochem. Commun. 2003;5:728.
    4. Garcia B., Lavallée S., Perron G., Michot C., Armand M. Electrochim. Acta. 2004;49:4583.
    5. Sato T., Masuda G., Takagi K. Electrochim. Acta. 2004;49:3603.
    6. Shin J.-H., Henderson W. A., Passerini S. J. J. Electrochem. Soc. 2005;152:A978.
    7. Armand M., Endres F., MacFarlane D. R., Ohno H., Scrosati B. Nat. Mater. 2009;8:621. - PubMed
    1. MacFarlane D. R., Huang J., Forsyth M. Nature. 1999;402:792.
    2. Zhou Q., Boyle P. D., Malpezzi L., Mele A., Shin J.-H., Passerini S., Henderson W. A. Chem. Mater. 2011;23:4331.
    1. Köddermann T., Wertz C., Heintz A., Ludwig R. ChemPhysChem. 2006;7:1944. - PubMed
    2. Borodin O., Smith G. D., Henderson W. J. Phys. Chem. B. 2006;110:16879. - PubMed
    3. Lassègues J.-C., Grondin J., Talaga D. Phys. Chem. Chem. Phys. 2006;8:5629. - PubMed
    4. Fujii K., Kanzaki R., Takamuku T., Kameda Y., Kohara S., Kanakubo M., Shibayama M., Ishiguro S., Umebayashi Y. J. Chem. Phys. 2011;135:244502. - PubMed
    5. Neto B. A. D., Meurer E. C., Galaverna R., Bythell B. J., Dupont J., Cooks R. G., Eberlin M. N. J. Phys. Chem. Lett. 2012;3:3435. - PubMed