in order to investigate electrochemical properties of a novel composite made from poly［3′

4′-ethylenedioxy2

2′:5′

2″-terthiophene］ (PTET) and carbon nanotubes (CNT)

a derivative of ethylenedioxysubstituted terthiophene was synthesized as the precursors via Stille reaction

and chemical polymerization method was used to prepare PTET-CNT nanocomposites by coating PTET on the surface of the CNT by FeCl3 as catalysts in dry CHCl3 at 0～5℃.The composite was characterized by Fourier transform infrared spectroscopy (FTIR)

transmission electron microscope (TEM) and scanning electron microscopy (SEM).FTIR spectra indicate that PTET of the composite more easily exists at the α

α′-positions than pure PTET，TEM and SEM images reveal that this composite has a core-shell structure with nanometer scale PTET layers.Electrochemical behavior of the composite electrode was evaluated by cyclic voltammetry (CV)

electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge tests with a threeelectrode system in 0.1 mol/L Et4NPF4/acetonitrile (AN) solution.CV curves of the composite electrodes indicate that the composites not only present a large background current

but also a couple of redox peak with potentials of Epa=1.2 V and Epc=-0.2 V(versus Ag/AgCl)

respectively.Galvanostatic chargedischarge curves show that the composite possesses higher specific capacitance and performs much better than carbon nanotubes under high current densities.A comparative analysis of original carbon nanotubes electrode was also conducted under similar conditions.At a current density of 3 mA/cm2

the PTET-CNT nanocomposite electrode exhibits high specific capacitance of 86 F/g

in comparison with a value of 20 F/g for the carbon nanotubes electrode

increased by 3.3 times than carbon nanotubes electrode.And supercapacitors based on the PTET-CNT nanocomposite and carbon nanotubes have an energy density of 2.02 and 0.47 Wh/kg

respectively.