Experimentally Assembled Electric Double Layer Capacitor using Carbonized and Activated Cotton Cloth and Water Electrolyte Solution

Abstract

The electric double layer capacitor (EDLC) electrode is made of carbonized and activated materials. The material surface and electrical characteristics of carbon materials produced from low cost organic materials were examined. First, a cotton cloth was carbonized and activated, and its optimal time and temperature of carbonization and activation processing were examined. And, its surface area, pore volume and pore size distributions were analyzed. Second, activated carbons were applied to the electrodes of 1Wh class EDLC cell with water electrolyte solution. The capacitances and internal resistances of the assembled EDLC cell were measured by a charge and discharge circuit using constant voltage source. And, the charge and discharge cycle test was performed on these assembled EDLC cells under practical use condition. As a result, EDLC cells using the activated carbon with large surface area of 1300m2/g showed the high density of capacitance 0.5-1.1F/cm2. The internal resistances of EDLC cells were less than 0.34W. It was also found that the EDLC cells had no deterioration in the charge and discharge cycle test under practical condition. It shows that the activated carbon made of cotton cloth contributes to the low cost and safety electrode of an EDLC.