Preparation and characterization of coaxial halloysite/polypyrrole tubular nanocomposites for electrochemical energy storage

Halloysite nanotubes/polypyrrole (HNTs/PPy) nanocomposites with coaxial tubular morphology for use as electrode materials for supercapacitors were synthesized by the in situ chemical oxidative polymerization method based on self-assembled monolayer amine-functionalized HNTs. The HNTs/PPy coaxial tubular nanocomposites were characterized with transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), electrical conductivity measurement at different temperatures, cyclic voltammetry (CV), and galvanostatic charge-discharge measurements. The coaxial tubular nanocomposites showed their greatest conductivity at room temperature and a weak temperature dependence of the conductivity from 298 K to 423K. A maximum discharge capacity of 522 F/g after correcting for the weight percent of the PPy phase at a current density of 5 mA cm(-2) in a 0.5 M Na2SO4 electrolyte could be achieved in a half-cell setup configuration for the HNTs/PPy composites electrode, suggesting its potential application in electrode materials for electrochemical capacitors. (c) 2010 Elsevier Ltd. All rights reserved.