poly-ethylenedioxythiophene (pedot)conformally coated on aligned carbon nanotube arrays for supercapacitor electrodes
Open Access
Author:
Kosolwattana, Suppanat
Graduate Program:
Materials Science and Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 28, 2013
Committee Members:
Qiming Zhang, Thesis Advisor/Co-Advisor
Keywords:
PEDOT carbon nanotube supercapacitor
Abstract:
Symmetric supercapacitors with aligned carbon nanotube (A-CNT) electrodes have showed a promising performance as an energy storage device. A-CNTs morphology presents high surface area for forming double layer charge storage with electrolyte ions. In this study, 3,4-ethylenedioxylthiophene (PEDOT) conducting polymer is selected to coat on A-CNTs electrodes to provide pseudo-capacitance from fast faradic reactions with electrolyte ions. Ionic liquid 1-ethyl-3-methylimidazolium tetrafloroborate (EMIBF4) in propylene carbonate (PC) is utilized as the electrolyte in chapter 3 to analyze the performance of coating material. Then, two other ionic liquids, N-Butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide (EMITFSI) are introduced to find the suitable electrolyte for new coated electrodes. The performance of the device, such as power density, energy density, capacitance and conductivity, are investigated by using impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge experiment. Electrode composition, surface area and morphology are determined from scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The conducting polymer coated on ACNTs is expected to increase surface area, produce pseudo-capacitance, and support the electrode structure. These improvements will lead to high performance supercapacitor.
