Conductivity and dielectric behaviour of PEO-based solid nanocomposite polymer electrolytes

In this research, thin films of poly(ethylene oxide) (PEO) blend with lithium hexafluorophosphate (LiPF6) salt and ethylene carbonate (EC) as plasticiser and carbon nanotube (CNT) as filler, are prepared using solution casting method. The conductivity and dielectric response of the nanocomposite polymer electrolyte systems are studied within the broad frequency range of 5 Hz-5 MHz and within a temperature range of 298-373 K. The conductivity-temperature plots are observed to be of Arrhenius nature. The dielectric behaviour is analysed using the dielectric permittivity (epsilon(r) and epsilon(i)), loss tangent (tan delta) and electric modulus (M-i and M-r) of the samples. It is observed that the dielectric permittivity rises sharply towards low frequencies due to electrode polarisation effects. The maxima of the loss tangent (tan delta) shifts towards higher frequencies and the height of the peak increases with increasing temperature. (C) 2011 Elsevier Ltd. All rights reserved.