Patent ID: 8790537
Filing Date: 2014-07-29
Classification: C08F,G02F,H01M

Abstract:
1. A process for the preparation of polymer electrolytes using ionic liquids comprising the steps of: (a) preparing 1-ethyl, 3-methyl imidazolium bromide (EMIBr) by reacting 1-methylimidazole with ethyl bromide in cyclohexane, under reflux for a period of 8-12 hrs, followed by recrystallization using a mixture of ethyl acetate and isopropyl alcohol under rotatory evaporation, at a temperature of 60-70° C. for a period of 0.5 hour, (b) decolorizing the above said compound of EMIBr by adding activated charcoal and boiling the solution mixture, at a temperature of 70-80° C. for a period of 2-10 minutes and subjecting the resultant decolorize compound to ion exchange reaction by using lithium salt of Lithium bis (trifluoromethene sulfonyl) imide [LiTFSI] or lithium bis (perfluoromethene sulfonyl) imide [LiBETI] in deionized water, at a temperature of 60-70° C., for a period of 7-8 hours and separating the bottom layer by known method followed by washing with water and dehydrated under vacuum and filtration by known method to obtain the desired hydrophobic ionic liquid, (c) mixing a polymerizable material with the ionic liquid solution and subjecting the obtained mixture to in situ polymerization in the presence of one or more additives forming a polymerizing solvent to obtain the polymer electrolyte, wherein the additive is an initiator optionally in combination with one or more additives selected from the group consisting of cross linkers, aprotic organic solvent, and a stiffening agent, wherein the cross linker is acrylamide, and further wherein the polymerizable material is a vinyl monomer.