Time-domain modeling of constant phase element for simulation of lithium batteries under arbitrary charging and discharging current profiles

Abstract

Derivation of a time-domain model for predicting the voltage-current characteristics of lithium batteries under arbitrary charging and discharging current profiles will be presented. The methodology is based on firstly formulating the generic time-domain voltage-current characteristics of a constant phase element (CPE) unit and then applying the model for multiple CPEs in the battery electrical model. A decimation technique will be applied to minimize the computational burden, and the numerical stability of the entire model will be studied. Finally, the accuracy of the developed time-domain model is verified by comparing the results with the measurement results obtained from a hardware testbed and with the simulation results obtained from the models with multiple parallel resistor-capacitor units.