Impedance spectroscopy of carbon nanotube/solid polymer electrolyte composites

New composite polymer electrolytes (CPE) have been prepared by a solution-casting technique, using polyethylene oxide, lithium hexafluorate (LiPF6) as the doping salt, ethylene carbonate (EC) as the plasticizer and amorphous carbon nanotubes ( α CNTs) as the filler. The crystallinity and ionic conductivity of the CPE are examined. Differential scanning calorimetry shows a decrease in melting temperature and crystallinity upon the addition of LiPF6, EC and α CNTs to the polymer electrolyte system. The addition of salt increases the conductivity up to 10−5 S cm−1. The incorporation of EC and α CNTs into the salted polymer shows a significant conductivity increase of 10−4 and 10−3 S cm−1. The complexation process is examined using Fourier transform infrared spectroscopy. The Vogel–Tamman–Fulcher (VTF) plots suggest that the temperature dependence of conductivity is a thermally activated process.