Prediction of Charge-Discharge and Impedance Characteristics of Electric Double-Layer Capacitors Using Porous Electrode Theory

Abstract

© The Author(s) 2017. Published by ECS. All rights reserved. Two first-principles modeling methods were used to analyze and quantitatively predict performance characteristics of Electric Double-Layer Capacitors (EDLCs), namely Time-Domain Current Method (TDCM) and Frequency-Domain Admittance Method (FDAM). TDCM was used to model galvanostatic discharge characteristics of capacitor while FDAM was used to model the impedance spectra. Both the methods showed excellent agreement with experimental impedance and galvanostatic discharge performance of various electrochemical capacitors made using two different commercial carbons. Details at the macroscopic (porous electrode theory) and microscopic (double layer theory) level were incorporated into the models. The methods were also able to follow changes in capacitance and resistance of the capacitor during cycling. Furthermore, FDAM was used to validate the performance of a large-scale commercial EDLC capacitor.