Conductivity studies on poly(methyl methacrylate)-Li2SO4 polymer electrolyte systems

Thin-film ion-conducting polymer electrolytes based on poly(methyl methacrylate) (PMMA) complexed with Li2SO4 have been prepared using the solution casting technique. The complexation of salt with PMMA was confirmed by structural and thermal studies. The results of the electrical conductivity measurements in these electrolytes are reported. A Vogel-Tammann-Fulcher-like temperature dependence of ionic conductivity implies coupling of the ion movement with the segmental motion of the polymer chains in the cross-linked environment. Predominant formation of contact ion pairs of Li2SO4 has been consistently observed through conductivity, X-ray diffraction, Fourier transformation and thermal analysis studies. (C) 2003 Elsevier B.V. All rights reserved.