JEE_V10_N4_RP1 Rajiv Kumar Journal on Electrical Engineering 2230–7176 10 4 6 12 Nano-composite, Conductivity, Donor Number, Dimethylformamide, Propylene Carbonate Proton conducting nano-composite polymer gel electrolytes containing Polymethylmethacrylate (PMMA), Benzoic Acid (BA), Ethylene Carbonate (EC), Propylene Carbonate (PC), Dimethylformamide (DMF), and nano-sized Alumina (Al O ) 2 3 have been prepared and characterized by electrochemical impedance spectroscopy. The effect of donor number of solvent used and nano-sized alumina on ionic conductivity of gel electrolytes has been studied. Maximum room -4 temperature conductivity of 1.83 x 10 S/cm for nano-composite polymer gel electrolytes at 7 wt% concentration of Al O along with good mechanical stability has been obtained. Two conductivity maxima have been observed with the 2 3 addition of nano-sized alumina. First maximum at low Al O concentration has been explained due to the enhanced 2 3 dissociation of undissociated acid/ion aggregates, whereas second maximum at high concentrations is due to formation of a high conducting interfacial layer between nano-particles and polymer gel electrolytes. The variation of conductivity with temperature and time has also been studied to check the stability of electrolytes. The change in conductivity with temperature is very small, which is desirable for their use in various electrochemical devices. April - June 2017 Copyright © 2017 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=13509