Complex Capacitance Analysis on Porous Carbon Electric Double-layer Capacitor (EDLC) Electrodes

摘要

A new analytical methodology, the complex capacitance analysis, is developed for electric double-layer capacitor (EDLC) electrodes. The theoretical derivation illustrates that several important EDLC parameters can be readily estimated from the imaginary capacitance profiles (C_(im) vs. log f): (ⅰ) total capacitance from the area of capacitive peak, (ⅱ) rate capability from the peak position, and (ⅲ) leakage current from the resistive tail. The more quantitative EDLC parameters can be obtained by a nonlinear fitting to the experimental data. The usefulness of this method is demonstrated by applying to practical porous carbon EDLC electrodes.