Ionic liquids as electrolytes

The behavior of ionic liquids as electrolytes is strongly influenced by the transport properties of their ionic constituents. These transport properties relate to the rate of ion movement and to the manner in which the ions move (as individual ions, ion-pairs, or ion aggregates). Conductivity, for example, depends on the number and mobility of charge carriers. If an ionic liquid is dominated by highly mobile but neutral ion-pairs it will have a small number of available charge carriers and thus a low conductivity. The two quantities often used to evaluate the transport properties of electrolytes are the ion-diffusion coefficients and the ion-transport numbers. The diffusion coefficient is a measure of the rate of movement of an ion in a solution, and the transport number is a measure of the fraction of charge carried by that ion in the presence of an electric field. 

GENERAL PROPERTIES OF IONIC LIQUIDS AS ELECTROLYTES FOR CARBON-BASED DOUBLE LAYER CAPACITORS... 

The general aim of this work is to show the properties of activated carbon-ionic liquid interface (AC-IL) as well as performance of capacitors based on activated carbons as electrode materials and ionic liquids as electrolytes. 

Further examples of recent attempts to reduce the consumption of electrical energy are the electrolysis of aqueous solutions of methanol (but CO2 is still produced at the anode) [78, 79] and water electrolysis using ionic liquids as electrolytes [80]. In the latter case, the authors claimed the possibility of obtaining high hydrogen production efficiencies using an inexpensive material such as low-carbon steel. 

Sakata M, Yoshida Y, Maesato M, Saito G, Matsumoto K, Hagiwara R (2006) Preparation of superconducting (TMTSF)2NbF6 by electrooxidation of TMTSF using ionic liquid as electrolyte. Mol Cryst Liq Cryst 452 103-112... 

Figure 9-1 Sensor device for measurement of relative humidity, containing an ionic liquid as electrolyte (with permission of Novasina S.A.)...

Galinski, M., Lewandowski, A., and Stgpniak, L, Ionic liquids as electrolytes, Electrochim. Acta, 51, 5567,2006. 

Lewandowski, A. and Galmski, M., General Properties Of Ionic Liquids As Electrolytes For Carbon-based Double Layer Capacitors, New Carbon Based Materials for Electrochemical Energy Storage Systems, Barsukov et al. (Eds), Springer, The Netherlands, 2006, 73-83. 

Bioelectrochemical sensors using ionic liquids as electrolyte medium... 

Vaher, M., Koel, M., and Kaljurand, M., Ionic liquids as electrolytes for nonaqueous capillary electrophoresis. Electrophoresis, 23, 426-430, 2002. 

In this chapter we have briefly discussed the high potential of air- and water-stable ionic liquids as electrolytes for metal deposition. Their extraordinary physical properties, superior to those of water or organic solvents, and their stability, open the door to the electrodeposition of many metals. Some advantages of air- and water-stable ionic liquids in electrodeposition are that they are quite easy to purify and handle and in most cases they do not decompose under environmental conditions. They can have pretty wide electrochemical windows of up to 6 V, and hence they... 

The potential benefits of using ionic liquids as electrolytes in conducting polymer devices have been investigated by a number of authors in recent years, for applications such as actuators [8-17], supercapacitors [18-20], electrochromic devices [12, 21] and solar cells [22], with significant improvements in lifetimes and device performance reported. 

In Section 8.2 the basics of pulsed dectrodeposition (PED) will be described for the case of aqueous electrolytes which allow the deposition of comparatively noble metals like Cu, Ni, Pd, or Au less noble metals like Fe or Zn can still be electrodeposited from aqueous electrolytes because they exhibit a comparatively large overpotential for hydrogen evolution. However, the main limitation of aqueous dectrolytes, of course, is their narrow electrochemical window which adversely affects the electrodeposition of metals like A1 or Ta. Therefore, recently, the PED technique has been extended to ionic liquids as electrolytes. General electrochemical aspects of ionic liquids can be found in Ref. [44] here, in Section 8.3, we will only address the technical aspects with respect to PE D. Examples of nanometals and nanoalloys electrodeposited from chloroaluminate-based ionic liquids are given in... 

Barisci J N, Wallace G G, MacFarlane D R, et al. Investigation of ionic liquids as electrolytes for carbon nanotube electrodes. Electro-chem. Commun. 2004. 6, 22-27. 

Balducci A, Dugas R, Tabema P L, et al. High temperature carbon-carbon supercapacitor using ionic liquid as electrolyte. /. Power Sources. 2007. 165, 922-927. 

Lewandowski A, Swiderska-Mocek A (2009) Ionic liquids as electrolytes for li-ion batteries-an overview of electrochemical studies. J Power Sources 194 601-609... 

Wang P, Null Y, Yang J, Feng Z (2006) Mixed ionic liquids as electrolyte for reversible deposition and dissolution of magnesium. Surf Coat Technol 201 3783-3787... 

J. Ding, D. Zhou, G. Spinks, G. Wallace, D. Forsyth, M. Fors)hh, and D. MacFarlane, Use of ionic liquids as electrolytes in electromechanical actuator systems based on inherently conducting polymers, Chem. Mater., 15 (12), 2392-2398 (2003). 

DEM 13] Demarconnay L., Calvo E.G., TIMPERMAN L., et al, Optimizing the performance of supercapacitors based on carbon electrodes and protic ionic liquids as electrolytes , Electrochimica Acta, vol. 108, pp. 361—368, 2013. 

Timperman, L., F. Beguin, E. Frackowiak, and M. Anouti. 2014. Comparative study of two protic ionic liquids as electrolyte for electrical double-layer capacitors. Journal of the Electrochemical Society 16LA228-A238. 

Brandt, A., J. Pires, M. Anouti, and A. Balducci. 2013. An investigation about the cycling stability of supercapacitors containing protic ionic liquids as electrolyte components. Electrochimica Acta 108 226-231. 

Mayrand-Provencher, L., S. X. Lin, D. Lazzerini, and D. Rochefort. 2010. Pyridinium-based protic ionic liquids as electrolytes for RuOj electrochemical capacitors. Journal of Power Sources 195 5114—5121. 

Benedetti, T. M., V. R. Gonzales, S. I. C. de Torresi, and R. M. Torresi. 2013. In search of an appropriate ionic liquid as electrolyte for macroporous manganese oxide film electrochemistry. Jourrml of Power Sources 239 1-8. 

Balducci, A., W. A. Henderson, M. Mastragostino, S. Passerini, P. Simon, and F. Soavi. 2005. Cycling stability of a hybrid activated carbon//poly(3-methylthiophene) supercapacitor with V-butyl-V-methylpyrrolidinium hisftrifluoromethanesulfonyl) imide ionic liquid as electrolyte. Electrochimica Acta 50 2233-2237. 

Orita, A., K. Kamijima, and M. Yoshida. 2010. Allyl-functionalized ionic liquids as electrolytes for electric double-layer capacitors. Journal of Power Sources 195 7471-7479. 

Timperman, L., H. GaUano, D. Lemordant, and M. Anouti. 2011. Phosphonium-based protic ionic liquid as electrolyte for carbon-based supercapacitors. Electrochemistry Communications 13 1112—1115. 

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