Probing the dielectric relaxation processes and their correlation with ions transportation in the complexes of plasticized nanocomposite solid polymer electrolyte

Abstract

Plasticized nanocomposite solid polymer electrolyte (PNSPE) film consisted of poly(ethylene oxide) and poly(methyl methacrylate) blend as host matrix, lithium perchlorate salt as ions dopant, ethylene carbonate as plasticizer, and montmorillonite clay nanoplatelets as inorganic nanofiller has been prepared by solution cast followed by the melt pressing. X-ray diffraction study of the PNSPE film confirms its amorphous structure with the existence of exfoliated nanoplatelets of the nanofiller. Dielectric and electrical dispersion of the film has been characterized systematically by employing the dielectric relaxation spectroscopy in the frequency range 2 × 101 to 1 × 106 Hz, at different temperatures. The relaxation times attributed to the various processes of structural dynamics of the PNSPE film have been probed by considering the individual spectrum of all the dielectric and electrical functions which are further validated by their master plot representation. The relaxation times corresponding to the dynamics of the electric double layers, electrode polarization, and interfacial polarization-affected polymer chain segments, cations coordinated polymers chain segments, and also the ionic conductivity in the ion–dipolar–nanofiller coordinated structures of the film have been determined. A generalized behaviour of these relaxation processes for probing the dynamical structures in all the solid polymer electrolytes has been demonstrated. It is further explored that these relaxation times of the PNSPE film exhibit a correlation with the dc ionic conductivity, and their temperature-dependent variation obeys the Arrhenius behaviour of nearly the same relaxation activation energies which are also found in good agreement with the conductivity activation energy.