Advanced Supercapacitors based on Microscale Carbon Structures

Abstract

A Supercapacitor is an electrochemical device which has a higher energy density than a battery and a high power density than a conventional capacitor. Other than an activated carbon material, carbon nanotubes draw an attention to be also used as a promising electrode material because of its porous structure. The electrode materials have been tested by an electrochemical characterization technique known as a cyclic voltammetry mostly in three electrode electrochemical cell configuration. The influence of the position of the electrodes on the results of the experiment was investigated during this work. Other factors such as the area of the electrode material, the weight of the material, and the operating voltage are also influencing the performance of the electrode material. The different kinds of carbon materials such as a carbon nanotubes, glassy carbon, carbon nanowalls and graphite have been compared in terms of their energy storage capability by conducting series of cyclic voltammery experiments with various electrolytes. Among the tested electrolytes are an aqueous sodium chloride electrolyte, 1-Ethyl-3-methylimidazolium tetrafluoroborate and 1-Ethyl-3 methylimidazolium bis (trifluoromethylsulfonyl) imide. From the tested carbon material, the carbon nanotubes coated polycarbonate membrane was used in the development of a prototype capacitor set-up because of its comparable best performance, easy and sustainable handling.