Imidazolium-Based Anion Exchange Membranes for Alkaline Anion Fuel Cells: Elucidation of the Distribution of ions and its Impact on the Ion Conductivity

The structure of ion-rich regions and the correlations between the ion conductivity, hydration level and morphology of AEMs with different grafting degrees have been studied in this work. Our results showed that ions in these AEMs distribute separately. The mean distance between two separated cations in AEMs increases with the relative humidity (RH), but is almost a constant for AEMs with different GDs at the same RH. Comparing to the AEMs equilibrated in liquid water, there is insufficient water to form well-connected hydrated regions when the AEMs were equilibrated at a specific RH, and hence the ion conductivity is much lower than that in liquid water. Beyond a threshold, the onset of percolation for the hydrated network, ion conductivity at a specific RH, i.e. 80%RH, is proportional to the hydration level and inversely proportional to the mean distance between two cations.第59回放射線化学討論