Electrochemical capacitors: Ionic Liquid Electrolytes

Double-layer carbon supercapacitors (electrochemical double-layer capacitor (EDLCs)) based on two carbon electrodes of high surface area separated by an electrolyte are the most popular electrochemical supercapacitors. The charge process is electrostatic with charge separation at the two electrode–electrolyte interfaces. The EDLCs can thus be modeled with two capacitances in series with what is called equivalent series resistance (ESR). Given that the electrode capacitance depends on the reciprocal of the double-layer thickness, and that it is directly related to the carbon surface area, typically of several hundred square meters per gram of carbon, the capacitance of EDLCs is significantly higher than that of the dielectric and electrolytic capacitors. The stored energy of EDLCs is also higher than that of the dielectric and electrolytic capacitors, but it is lower than that of batteries.....