Structural and electrical characterization of plasticized PVA: AgI polymer electrolyte

The development of new polymeric systems with high ionic conductivity is one of the main objectives in the field of polymer materials with application point of view. In the present work, Ag+ ion conducting solvent free composite polymer electrolyte thin films have been prepared using polyvinyl alcohol (PVA) as host polymer and polyethylene glycol (PEG) as plasticizer by standard solution cast technique. The structural characteristics of the prepared films have been obtained from X-ray diffraction (XRD) patterns. Maximum room temperature ionic conductivity of order of 10(-5) S cm(-1) is obtained using complex admittance (B-G) spectroscopy. The temperature dependent conductivity shows two distinct regions of Arrhenius type thermally activated behavior before and after glass transition temperature. Dielectric constant, epsilon' and dielectric loss, epsilon '' of the samples increases with temperature which is similar in behavior as that of conductivity. The activation energy for ion conduction has been calculated from temperature dependent conductivity curve and its minimum value is found to be 0.30 eV for PVA-PEG-20% AgI polymer electrolyte sample. High value of transference number shows that samples are ionic in nature which is confirmed by Wagner's polarization technique.