Preparation and characterization of imidazolium-based membranes for anion exchange membrane fuel cell applications

- Imidazolium-based AEMs with different ion exchange capacities were prepared.
- The AEMs showed conductivity up to 1.0 × 10−2 S cm−1 at 90 °C.
- The AEMs showed good alkaline stability in 2 M KOH solution at 80 °C.
- The phase separation phenomenon could be observed in the AFM images of membranes.

New anion exchange membranes (AEMs) with high conductivity, good dimensional and alkaline stability are currently required in order to develop alkaline fuel cells into efficient and clean energy conversion devices. In this study, a series of AEMs based on 1, 2-dimethyl-3-(4-vinylbenzyl) imidazolium chloride ([DMVIm][Cl]) are prepared and investigated. [DMVIm][Cl] is synthesized and used as ion carriers and hydrophilic phase in the membranes. The water uptake, swelling ratio, IEC and conductivity of the AEMs increase with increasing the [DMVIm][Cl]. The imidazolium-based AEMs show excellent thermal stability, sufficient mechanical strength, the membrane which containing 30% mass fraction of [DMVIm][Cl] shows conductivity up to 1.0 × 10−2 S cm−1 at room temperature and good long-term alkaline stability in 1 M KOH solution at 80 °C. The results of this study suggest that this type of AEMs have good perspectives for alkaline anion exchange membrane fuel cell applications.