The development of ion conductive membranes are vital for electrochemical separations and electrical devices. With previous research focused on developing stable electrolytes with unique chemistries, focus on ionic liquid materials has gained significant attention over the past few years. Ionic liquids are versatile, stable solvents with high conductance and negligible vapor pressure making them ideal candidates for ion conducting materials. However, creating stable films with ionic liquids has proved challenging due to issues with increasing mechanical and thermal stability while maintaining good ion properties. This study investigated the development of poly(ionic liquid)/ionic liquid composite membranes through the development of polymer/ionic liquid blends which were cast as films and cross-linked for mechanical stability through radical polymerization. Free ionic liquid was then introduced into the cross-linked membranes to further enhance membrane stability and ion conductance. Results indicated that dry films were stable, but brittle with less than ideal ion conductivities (10-5 S/cm at 105 °C). Addition of free ionic liquid resulted in more flexible films and increases in ion conductance by 1-2 orders of magnitude (10-4 – 10-3 S/cm at 105 °C). Addition of free ionic liquid greater than 30 wt% resulted in tacky films with good ion properties, but non-ideal mechanical stability. Influence of cross-linking polymer was also investigated with results indicating that carbon chain length had a negligible impact on material performance. Through this work, stable poly(ionic liquid)/ionic liquid composite membranes were synthesized with high temperature conductance and good mechanical properties.

Poly(ionic liquid)/ionic liquid composite membranes for high temperature ion ConductancePoly(ionic liquid)/ionic liquid composite membranes for high temperature ion conductance

251st National Meeting (2016)

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