Development of new class of ion conductive polymers based on ionic liquids

A series of polymerizable ionic liquid was synthesized and polymerized to prepare new type polymer electrolytes. The effects of position of imidazolium cation, spacer structure and length, and anion species on the ionic conductivity have been investigated. Polycation-type ionic liquids having flexible long spacer showed the ionic conductivity of about 10(-4) S cm(-1) at room temperature. Polyanion-type ionic liquids without spacer structure also showed about 10(-4) S cm(-1) at room temperature. Both examples strongly suggested that the freedom of imidazolium cation affected greatly on the ionic conductivity. Both systems maintained quite low glass transition temperature of about -60degreesC after polymerization. (C) 2004 Elsevier Ltd. All rights reserved.