Ionic conductivity of lithium perchlorate salt in polymeric electrolyte solutions and MMT nano-sheets dispersed colloids

Abstract

The relative complex dielectric function and ionic conductivity of polymeric electrolyte solutions in acetonitrile comprises of poly(ethylene oxide) (PEO), poly(methyl methacrylate) (PMMA), PEO-PMMA blend and lithium perchlorate with 8:1 ratio of polymer monomer units to the lithium cations are investigated over the frequency range 20 Hz to 1 MHz, and temperatures 15, 30 and 45^oC. The dc ionic conductivity of PEO containing electrolyte solution (8.56 mS cm^–1) is found higher as compared to that of the PMMA (4.85 mS cm^–1) and PEO–PMMA blend (7.9 mS cm^–1) at 15^oC. The temperature dependent ionic conductivity, electrode polarization relaxation time and viscosity of these electrolyte solutions obey the Arrhenius behaviour, whereas the product of ionic conductivity and viscosity is governed by the Stokes-Einstein model. These parameters of PEO-PMMA blend electrolyte colloids have an initial decrease with loading of 1 wt% montmorillonite (MMT) clay as nanofiller and increase with further loading of MMT upto 10 wt%. The formation of cross-linked complexes and their effect on ions conduction mechanism in the electrolytes are discussed.