Description of supercapacitor performance degradation rate during thermal cycling under constant voltage ageing test.

Great research effort is currently devoted towards enhancing performance and operating time of electrical vehicle (EV). Classic storage element in EV consists of accumulators, which allow a relatively high autonomy. However, the power capability of these devices can be considered as insufficient. Supercapacitors (SC) are a new promising storage system used in EV to minimize this lack thanks to their high power capability. One of the ageing cause for SCs for this application is the day/night cycling, that is why we study the impact of thermal cycling on SC performances in this paper. In this article, and in order to have a descriptive sample, impacts of three thermal cycling ageing test conditions are compared with obtained results coming from simple calendar ageing tests at constant temperature and voltage. The comparison is based on physics modelling parameters evolution in the Constant Phase Element (CPE) and Multi-Pore (MP) models. These parameters are calculated based on experimental measurements during calendar ageing tests up to 14,000h and 6000h, 10,000h for thermal cycling tests. Finally, the study of modelling parameters highlights changes in the internal physical structure for both ageing tests.