Thermal Influence on the Electric Parameters and Microstructures of Activated Powder Double Layer Supercapacitors

The effect of the working temperature on the capacity, internal equivalent serial resistance (ESR), equivalent parallel resistances (EPR) of some retail available electric double layer capacitors (EDLC) have been investigated. Standard capacities of 1.0 F at a maximum potential of 5.5 V were employed in this study. EPR values have been calculated using the self-discharge curves at temperatures above to the nominal maximum working temperature of the supercapacitors (~70°C). The ESR values were measured during charge using the constant current (1 mAF-1) interrupt method with oscilloscope. Microstructural characterization of the electrode material have been carried out using scanning electron microscopy (SEM) and chemical microanalyses employing energy dispersive X-ray analysis (EDX).