Supercapacitor Electrodes Made from Mixture of Amorphous Carbon Nano-Particles and Carbon Black

Abstract

Electrodes for electric double layer supercapacitors (EDLS) usually made of a mixture of carbon black and binder material. However the binding mixture causes loss in the capacitance because after the polymerization it obstructs the pores of the carbon black, thus decreasing the active surface of the capacitor. The capacitance of the electrode can be increased by use of additive materials, which improve the electrochemical performance of the active material. The effect of amorphous carbon nano-particles, added to the carbon black on the performance of the supercapacitor electrodes was studied earlier. It was found that maximal value was obtained for the composition of 30 wt.% of amorphous carbon nano-particles and 70 wt.% of carbon black [1]. In this work test-piece supercapacitors (TPS) fabricated with non-aqueous Li-based electrolyte were studied to analyze the influence of the size of the TPS to the specific capacitance. These systems were examined by impedance, charge-discharge measurements and cyclic voltammetry. The working potential window of the capacitor was found to be the 0-1 V region. Increasing the area of the electrode by using Al foils of larger size resulted in proportional increase of the capacitance.