Electrical Impedance of Single Ion-Conducting Polymer Networks

Ionic liquids (ILs) - low temperature molten salts composed only of ions- have been widely investigated as promising ion conductive materials for a variety of electrochemical applications. ILs, however, possess critical limitation due to the intrinsically low mechanical integrity of liquid materials. These drawbacks can be overcome by mixing them with macromolecules or directly polymerizing them, yielding ion-conducting solid or gel electrolytes. Such materials combine many of the attractive properties of ILs along with the flexibility and mechanical strength of polymers. In the present work, we have selectively polymerized one of the ionic moieties to provide single ion—either cation or anion— conducting gels based on 1-ethyl-3-methyl imidazolium (3-sulfopropyl) acrylate ([EMIM][SPA]) and [(1-acryloyloxy) propyl]-3-methyl imidazolium bis-(trifloromethylsulfonyl) imide ([AEBI][TFSI]) and used these single ion conducting networks for fabrication of soft ionic P/N diodes. Our studies shed light on the impedance behavior of single ion conducting networks and open new opportunities for the application of these soft ionic diodes.