Modeling the Ageing Effect of Cycling Using a Supercapacitor-Module Under High Temperature With Electrochemical Impedance Spectroscopy Test

This paper contributes to the ageing studies of supercapacitor (SC) modules under different operational and environmental factors associated with SC ageing in electric vehicle/hybrid-electric vehicle (EV/HEV) applications, such as high temperature at 85°, constant charge, and variable load discharge cycling. The ageing behavior is quantified through the periodic monitoring of their electrical and electrochemical state of health with electrochemical impedance spectroscopy (EIS) characterization tests. The electrochemical results from EIS tests reveals detailed distinctions at different frequency region in relation to the ageing factor, which causes the deterioration in the SC electrical performance. Based on these distinctions, two electrical equivalent circuit models are developed to describe an initial model from a dormant cell, which transitioned to an ageing model as soon as an end-of-life criterion is observed. Experimental and simulation results are presented and compared.