Ion Conduction Phenomenon and Electrochemical Performance of Gel Polymer Electrolyte in EDLC Containing Blend Polymer Host, Ionic Liquid and Mixed Carbonate Plasticizers

A series of gel polymer electrolytes (GPEs) are prepared using a blend polymer host, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BDMIMBF4) ionic liquid (IL) and mixed organic carbonate-based plasticizers. Conductivity isotherms are analyzed using the modified Almond-West formalism. Ionic transport mechanism and relaxation dynamics are systematically studied using broadband dielectric spectroscopy over a wide frequency and temperature range. Electrical modulus and dielectric spectra are studied to get insight of the conductivity and segmental relaxation phenomena. DC conductivity, along with conductivity and segmental relaxation time followed Vogel-Tammann-Fulcher (VTF) relationship, instead of Arrhenius relationship, suggesting an existence of coupling between the ionic transport and segmental relaxation processes. The dc conductivity values are found to increase gradually with increasing content of IL. At 30 °C IL-200 composition shows a conductivity value of 1.8 × 10–3 S cm–1. Using IL-200 GPE an...