MG49-KOH-PC alkaline gel polymer electrolytes membrane for supercapacitors

The effects of addition of potassium hydroxide (KOH) as doping salt in 49 % poly (methyl methacrylate)-grafted-natural rubber (MG49) were investigated. The free standing polymer electrolyte films doped with various wt. %of KOH salt was prepared by solution cast technique. The interaction between polymer and salt was confirmed by Fourier Transform Infrared (FTIR) spectroscopy studies. Ionic conductivity of the electrolyte films were studied by AC Impedance Spectroscopy. The highest ionic conductivity value obtained for the solid polymer electrolyte (SPE) is ∼10⁻⁷ S cm⁻¹ at 25 wt. % of KOH. The increase and decrease in ionic conductivity are coupled with ion association and dissociation phenomena. Plasticized electrolyte film with 50 wt. % of PC exhibited an ionic conductivity of one order higher than the unplasticized film. The effect of ion associations is investigated and found to be closely related to the glass transition temperature (Tg) value of the film, in which decreases with the addition of propylene carbonate (PC) plasticizer.