AC CONDUCTIVITY STUDIES OF COMPOSITE POLYMERIC ELECTROLYTES

Ac conductivity studies carried out over a temperature range of 0-100 degrees C for polymeric electrolytes from the PEO-LiClO4-alpha-Al2O3 s ystem are reported. Electrolytes of various salt concentrations and co ntaining 15 mass% alpha-Al2O3 are studied. The contribution of charge carrier concentration and ion mobility to the de ionic conductivity of these composite polymeric electrolytes is discussed. A change in the temperature dependence of ionic conductivity is observed around the me lting point of the crystalline phase of the composite electrolytes. An increase in dielectric constant following this phase transition is al so observed. Above the melting temperature, an increase in the conduct ivity depends either on an increase in ionic mobility (samples with lo w salt concentration) br on the creation of charge carriers (samples w ith high salt concentration). (C) 1998 Published by Elsevier Science L td. All rights reserved.