Evaluation of double layer capacitor technologies for high power and high energy storage applications

As an emerging technology in the area of energy storage, the double layer capacitor is a promising device for certain niche applications. The double layer capacitor is a low voltage device exhibiting an extremely high capacitance value in comparison with other capacitor technologies of a similar physical size. Capacitors with values in excess of 1500 F are now available. The maximum voltage allowable on these devices is 3 V, limited by the dissociation of the organic electrolyte. This high capacitance derives from the high surface of activated carbon electrodes, and the high capacitance per unit area observed at the chemical double layer. This paper serves as a summarization of experiments and the characterization of currently available double layer capacitor technologies. Capacitors from 10 F to 1500 F were examined, both aqueous and organic electrolyte technologies were utilized, and a range of commercially available devices were selected for study.