Carbon / ionic liquid capacitor

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. 

Pinkert, K., M. Oschatz, L. Borchardt et al. 2014. Role of surface functional groups in ordered mesoporous carbide-derived carbon/ionic liquid electrolyte double-layer capacitor interfaces. ACS Applied Materials Interfaces 6 2922-2928. 

Lewandowski A, Galinski M (2004) Carbon-ionic liquid double-layer capacitors. J Phys Chem Solids 65 281-286... 

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

Capacitors made of high-surface carbon with PVdF-co-HFP as a binder and filled with neat ionic liquids, without any molecular solvent, show high specific capacity, up to 180 F/g [13],... 

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. 

Ania CO, Pernak J, Stefaniak F, Raymundo-Pinero E, Beguin F. Solvent-free ionic liquids as in situ probes for assessing the effect of ion size on the performance of electrical double layer capacitors. Carbon 2006 44 3113-3148. 

Based on these properties, the double-layer capacitor comprising from a pair of the activated carbon electrodes and the nonaqueous liquid electrolyte is the most favorable one from the viewpoint of energy density. Ionic liquids are a kind of nonaqueous liquid electrolytes. 

The development of high performance electrolytes is an important task in the production of devices for electric energy storage and delivery such as lithium ion batteries, capacitors, and electrochromic devices. Carbonate-based materials are one of the liquid electrolytes. Carbonate-based liquid electrolytes are now commonly used for the economical lithium ion batteries [31]. The solution of carbonate and lithium salts exhibits high ionic conductivity, on the order of 10-3 S cm-1 at ambient temperature. 

Fig. 4 shows the example of cyclic voltammetiy curves for an activated carbon at 5 mV s" using different electrolyte (aqueous, organic, ionic liquid), where it is well visible that the voltage range is imposed by the stability vrfndow of the electrolyte. These almost rectangular box like shape curves are characteristic of an ideal EDL capacitor, with low ESR. 

FIGURE 2.58 Capacitance as a function of electrode surface curvature radius and geometry for various open structure electrode geometries as obtained from MD simulations at the 4 V potential difference between electrodes. (Reprinted with permission from Vatamanu, J. et al., 2013. Increasing energy storage in electrochemical capacitors with ionic liquid electrolytes and nanostructured carbon electrodes. Journal of Physical Chemistry Letters 4 2829-2837. Copyright 2013 American Chemical Society.)... 

Vu, A., X. Y. Li, J. Phillips et al. 2013. Three-dimensionally ordered mesoporous (3DOm) carbon materials as electrodes for electrochemical double-layer capacitors with ionic liquid electrolytes. Chemistry of Materials 25 4137-4148. 

Largeot, C., P. L. Taberna, Y. Gogotsi, and P. Simon. 2011. Microporous carbon-based electrical double layer capacitor operating at high temperature in ionic liquid electrolyte. Electrochemical and Solid-State letters 14 A174-A176. 

Eluang, H. C., C. W. Huang, C. T. Hsieh, and H. Teng. 2014. Electric double layer capacitors of high volumetric energy based on ionic liquids and hierarchical-pore carbon. Journal of Materials Chemistry A 2 14963-14972. 

Nagao, Y, Y. Nakayama, H. Oda, and M. Ishikawa. 2007. Activation of an ionic liquid electrolyte for electric double layer capacitors by addition of BaTiOj to carbon electrodes. Journal of Power Sources 166 595-598. 

Kim, Y. J., Y. Matsuzawa, S. Ozaki et al. 2005. High energy-density capacitor based on ammonium salt type ionic liquids and their mixing effect by propylene carbonate. Journal of the Electrochemical Society 152 A710-A715. 

Krause, A., and A. Balducci. 2011. High voltage electrochemical double layer capacitor containing mixtures of ionic liquids and organic carbonate as electrolytes. Electrochemistry Communications 13 814-817. 

Protic Ionic Liquids as Electrolytes for Carbon-Based Pseudo-capacitors... 

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