Modeling of the Thermal Behaviors of an Ultracapacitor Module

Ultracapacitors, also known as supercapacitors, have the potential to meet the increasing power requirements of energy-storage systems for automotive applications. As compared to batteries, ultracapacitors offer a higher power density, higher efficiency, and longer shelf and cycle life. Because the performance of an ultracapacitor depends on temperature, it is important to calculate accurately the thermal behavior of a single ultracapacitor cell and the module composed of multiple ultracapacitor cells for the efficient and reliable systems integration of an ultracapacitor in automotive applications.

In this work, modeling is performed to study the thermal behavior of an ultracapacitor module. The ultracapacitor module is subject to the charge/discharge cycling with constant-current between 1.35V and 2.7V. The validation of the modeling approach is provided through the comparison of the modeling results with the experimental measurements.

Fig. 1 shows the schematic diagram of the ultracapacitor module composed of the 18 ultracapacitor cells (3.7V/3000F) from LS Mtron Ltd. In Fig. 2, the variation of surface temperature with time from the experiment is compared with that from modeling during the charge-discharge cycles with the constant current of 200 A.