Discharge characteristics of high energy storage double layer capacitors

The double-layer capacitor is a recent innovation that combines high surface area electrode materials with the high capacitance per unit area of the chemical double layer. Commercially available devices with a capacitance of 1500 F are now available (Matsushita, 1992). This improvement in rated capacitance has presented opportunities for the use of double layer capacitors in high power and/or high energy storage applications (Burke, 1995 and Hall, 1995). This paper examines the discharge performance characteristics of several capacitors, including both aqueous and organic electrolyte devices. A useful simplified model is assumed for the double layer capacitor, consisting of an equivalent series resistance (ESR) and a capacitor in series. Values for these two parameters are determined in this investigation under various discharge conditions, along with peak current during short circuit conditions