Double-layer capacitors electrolyte

West, W. C., M. C. Smart, E. J. Brandon, L. D. Whitcanack, and G. A. Plett. 2008. Double-layer capacitor electrolytes using 1,3-dioxolane for low temperature operation. Journal of the Electrochemical Society 155 A716-A720. 

Francke, R., D. Cericola, R. Kotz, G. Schnakenburg, and S. R. Waldvogel. 2011. Bis(2,2 -biphenoxy)borates for electrochemical double-layer capacitor electrolytes. Chemistry -A European Journal 17 3082-3085. 

Ue, M., M. Takeda, T. Takahashi, and M. Takehara. 2002. Ionic liquids with low melting points and their application to double-layer capacitor electrolytes. Electrochemical and Solid-State Letters 5 A119-A121. 

Orita, A., K. Kamijima, M. Yoshida, and L. Yang. 2010. Application of sulfonium-, thiophenium-, and thioxonium-based salts as electric double-layer capacitor electrolytes. Journal of Power Sources 195 6970-6976. 

Ishikawa, M., Morita, M., lhara, M. and Matsuda, Y., Electric double layer capacitor composed of activated carbon fiber cloth electrodes and solid polymer electrolytes containing alkylammonium salt, J. Electrochem. Soc., 1994, 141(7), 1730 1734. 

It follows from these data that the (theoretical) specific capacity of the active materials of such a double-layer capacitor may attain 100 F/g. This is many orders of magnitude above the values characterizing other capacitor types (film and electrolytic). For this reason such capacitors have also become known as super- or ultracapacitors. 

The operation of a double-layer capacitor is tied to a displacement of electrolyte ions. In a fully charged capacitor, anions accumulate as counterions in the solution layer next to the positively charged electrode while the eoncentration of the cations decreases. At the negative electrode, the opposite situation is seen. During discharge, the ionic concentrations level out to the bulk solution values by migration and diffusion. 

Porous carbons are among the most attractive electrode materials for electric double layer capacitors (EDLC), where the charge accumulation occurs mainly by electrostatic attraction forces at the clcctrode/electrolyte interface [1-3]. Advantages of this class of materials include high surface... 

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

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. 

Care is not always sufficiently brought to this electrode. An insoluble redox system, much more capacitive than the working electrode is often a good choice, or possibly a large double layer capacitor electrode, which does not pollute the electrolyte. 

Lust, E., Janes, A., and Arulepp, M. Influence of electrolyte characteristics on the electrochemical parameters of electrical double layer capacitors. J. Solid State Electr., 8, 2004 488-496. 

Ue M, Ida K, Mori S. Electrochemical properties of organic liquid electrolytes based on quaternary onium salts for electrical double-layer capacitors. Journal of the Electrochemical Society 1994 141(ll) 2989-2995. 

Zheng JP, Jow TR. The effect of salt concentration in electrolytes on the maximum energy storage for double layer capacitors. Journal of the Electrochemical Society 1997 144(7) 2417-2420. 

Farahmandi C, Dispennette J, Blank E, Kolb A. Maxwell Technologies. Multi-electrode double layer capacitor having single electrolyte seal and aluminium-impregnated carbon cloth electrodes. US patent /1996/000726728. 

Hahn M, Barbieri O, Campana P, Kotz R, Gallay R. Carbon based double layer capacitors with aprotic electrolyte solutions The possible role of intercalation/insertion processes. Applied Physics A 2006 82 633-638. 

In a simple case, the electrochemical reaction at the electrode-electrolyte interface of one of the electrodes of the battery can be represented by the so-called Randles circuit (Figure 8.19), which is composed of [129] a double layer capacitor formed by the charge separation at the electrodeelectrolyte interface, in parallel to a polarization resistor and the Warburg impedance connected in series with a resistor, which represents the resistance of the electrolyte. 

In the case of ion conductive polymers, gel polymer electrolytes which consist of a polymer matrix, organic solvents and supporting electrolyte, were introduced as novel nonaqueous electrolyte systems in electrochemical applications, such as rechargeable batteries and electric double layer capacitors [3-5], Recently, considerable attention has been devoted to the application of gel poly-... 

In recent years there has been increasing interest in the power capacitors, ultracapacitors or supercapacitors based on electrochemical systems. These include electric double layer capacitor (EDLC) types based on carbon electrodes with suitable electrolyte systems, and electrochemical capacitors with pseudocapacitance [34,35],... 

The double-layer capacitor is one of the electrochemical capacitors showing intermediate performances between conventional capacitors and rechargeable batteries from the viewpoint of energy and power densities. Although the terms supercapacitor and ultracapacitor are often used for double-layer capacitors, in a sense that they have higher capacitance than conventional capacitors (ceramic, film, aluminum electrolytic, or tantalum electrolytic capacitors), these terms are not to be used because they are the trademarks of certain companies products. 

The selection of the electrolyte material is dependent on the electrode type. In principle, any ionic conductors can be used as the electrolyte material of a double-layer capacitor as long as the current due to the electrochemical reactions (Faradaic current) does not flow in the desired potential region. The electrolyte merely works as an ion source to form a double-layer. 

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