The study of multiwalled carbon nanotube deposited with conducting polymer for supercapacitor

The performance of supercapacitors with multiwalled carbon nanotubes deposited with conducting polymer as activate materials was greatly enhanced in contrast with electric double-layer supercapacitor with carbon nanotubes due to the conducting polymer's faradaic effect. They are promising as the secondary power sources in electric vehicles propulsion. Polypyrrole and poly(3-methylthiophene) were uniformly deposited onto multiwalled carbon nanotubes in organic system by chemical methods. A carbon nanotubes-polypyrrole composite-carbon nanotubes-poly(3-methyl-thiophene) composite based supercapacitor prototype (CNTs-pPy-CNTs-pMeT SCP), a carbon nanotubes-carbon nanotubes-polypyrrole based hybrid SCP (CNTs-CNTs-pPy SCP), a carbon nanotubes-carbon nanotubes-poly(3-methylthiophene) based hybrid SCP (CNTs-CNTs-pMeT SCP) as well as a CNTs-CNTs corresponding SCP were assembled in 1 M LiClO4 acetonitrile solution. Their voltammetry characteristics, galvanostatic discharge and AC. impedance spectra were carried out in two-electrode mode. Pseudocapacitance effects are found out from those SCPs with composite electrodes and their measured capacitances are 87, 45 and 72 F g(-1) for CNTs-pPy-CNTs-pMeT SCP, CNTs-CNTs-pMeT SCP and CNTs-CNTs-pPy SCP, respectively. They are much larger than that. of 21 F g-1 for the CNTs-CNTs corresponding SCP, which is a double-layer SCP. Their measured specific energy is 1.82, 0.88 and 1.33 W h kg for those SCPs with composite electrodes. They are also much higher than that of 0.58 W h kg(-1) for the CNTs-CNTs corresponding SCP. (C) 2002 Elsevier Science Ltd. All rights reserved.