Ion Conduction Mechanism in Solid Polymer Electrolyte: An Applicability of Almond-West Formalism

摘要

Dielectric response and ac conductivity analysis of an ionically conducting polymer film based onpolymethyl methacrylate (PMMA) as the host polymer have been carried out. The effect of frequencyand salt concentration on the dielectric relaxation and on the ac conductivity has been observed. Thedielectric behavior was analyzed via the dielectric permittivity (蝿) and dissipation factor (tan ) of thesamples. The analysis has shown the presence space charge polarization at lower frequencies.Evidences of dielectric and conductive relaxation phenomena have also been traced. The dielectricpeak has been observed to shift toward the higher frequency side with the addition of LiClO4 salt,suggesting a lowering the sample viscosity and the barrier to ion mobility. The real part of acconductivity spectra of these materials obeys the Jonscher power law, where the calculated value of thepower law exponent n lies between 0.5 and 1, which confirms that the electrical conductivity in thepolymer nanocomposite electrolytes (PNCs) is primarily due to ionic transport. The hopping rate,carrier concentration term, has been determined using Almond-West formalism. A good correlationamong dielectric permittivity, carrier concentration and ionic conductivity has been observed.