Determination of reliable resistance values for electrical double-layer capacitors

The power capabilities of supercapacitors are strongly influenced by their passive elements. Within this study, we investigate methods to address resistive components out of galvanostatic measurements and we compared literature methods with the aim to provide a guide to correctly exploit the resistance of supercapacitors. The impact of the sampling conditions of galvanostatic measurements is analyzed and related to electrochemical impedance spectroscopy. Further, a novel method based on the instantaneous power analysis is provided to get real-time information concerning the actual cell resistance during the measurement without altering the galvanostatic experiment. Measurements show that literature methods can provide values close to the series resistance, while the newly proposed power method results in a good estimate of the actual dissipative value.