Nanocomposite Electrodes For Electrochemical Supercapacitors

Abstract

Supercapacitor electrodes were fabricated at a high active mass loading and exhibited enhanced electrochemical capacitance. A conceptually new salting-out extraction processing technique for the synthesis of dispersed Mn3O4-carbon nanotube (CNT) nanocomposites was developed, alleviating the need for hydrophobic solvents. The choice of isopropyl alcohol and NaCl for the extraction process offer advantages of an easy upscaling of this process. The salting out technique was shown to work with Octanohydroxyamic acid (OHA) and Lauryl Gallate (LG) as extractors and dispersants, critical to the success of the extraction. Mechanisms for surface adsorption on Mn3O4 and CNT for both OHA and LG are discussed. A secondary project was also undertaken, to investigate the use of chlorogenic acid and 3,4,5 – trihydroxybenzamide, as co-dispersing agents for MnO2 and CNTs. These molecules are used due to their unique structural properties, which are discussed. The electrodes fabricated using these co-dispersants showed significant increases in their specific capacitances and SEM imaging indicated improved mixing, compared to samples prepared without dispersants. A specific capacitance of 6.5 F g-1 was achieve at low electrical resistance, attributed to the microstructure of electrodes prepared with the co-dispersant molecules.