Using a Debye polarization cell to predict double-layer capacitor performance

Double-layer capacitors (DLCs) are relatively complex devices. Different models have been proposed for DLCs. Presented in this paper is an evaluation of the Debye Polarization cell as a model for a double-layer capacitor. The elements in this circuit model can be related to the chemical reactions which occur inside the DLC. Circuit element values are found from AC impedance measurements for a DLC and a computer program which utilizes a nonlinear least squares fitting technique. Variations in circuit element values with DC bias level and manufacturing have been investigated. The performance of the Debye polarization cell in slow discharge and pulse load applications has been compared to actual circuit measurements and to simulated results using a classical equivalent circuit