Contribution of calendar ageing modes in the performances degradation of supercapacitors during power cycling

摘要

Due to their high specific power and their long cycle life, supercapacitors (SC) are very interesting devices for on-board energy applications such as hybrid-electric vehicles. However, in order to ensure optimal performances during the whole vehicle lifetime, the reliability of the SC must be quantified. Thus, accelerated ageing modes based on both calendar life tests and power cycling tests have been investigated and the performances degradation of the SC was quantified using periodic characterization tests based on impedance spectroscopy measurements. Hence, the aim of this paper is to determine the contribution of calendar ageing modes in the performances fading of supercapacitors during power cycling. The degradation of the performances was quantified through the monitoring of the parameters for a SC impedance model. Then, the results of calendar life tests were used to define an equivalent acceleration factor for power cycling by considering the impact of the voltage and the temperature individually. The obtained results confirm that the evolution of model parameters during power cycling corresponds to an equivalent calendar ageing, leading to a global approach for the study of the supercapacitors ageing.