Supercapacitors are electrochemical energy storage devices primarily attractive for their fast charging and discharging capability, long lasting stability and safe handling. Because of these unique qualities, supercapacitors are ideal candidates for a number of applications including regenerative breaking in cars, static random access memory and motor starters. To date, three main material classes have been investigated for electrode applications. These include carbonaceous materials, metal oxides and polymers or their composites. Metal oxide based supercapacitors have high capacitance, but severely suffer in stability, making carbonaceous materials that store charges through double layer adsorption mechanism particularly attractive. In addition, carbonaceous materials are relatively non-toxic, chemically inert, stable at high temperatures, easily accessible and often sustainable. Here, we study the effect of chemical treatment on the electrochemical properties of commercial carbon nanotubes (CNT). Structural and electrochemical properties of untreated, sulfuric acid treated and KOH activated CNT was studied. It was observed that surface area of the CNT changes with such treatment. Surface area of 210, 236 and 239 m2/g was observed for untreated, sulfuric acid treated and KOH activated CNT, respectively. Electrochemical investigations suggested that such treatment reduces the charge storage capacity of CNT which could be due to creation of some functional groups on the surface of CNT which increases its resistivity. Specific capacitance of 730, 620 and 626 F/g was observed for untreated, sulfuric acid treated and KOH activated CNT, respectively at 2 mV/s of scan rate. Similar observation was observed in galvanostatic charge-discharge studies, where a specific capacitance of 260, 208 and 224 F/g was observed for untreated, sulfuric acid treated and KOH activated CNT, respectively at 500 mA/g of current density.
Morey, Tucker, "Effect of Chemical Treatment on the Electrochemical Properties of Carbon Nanotubes" (2017). Paper Presentations. 20.