Blend anion exchange membranes containing polymer of intrinsic microporosity for fuel cell application

High hydroxide conductivity and alkali resistance of anion exchange membranes (AEMs) is the basic requirement for realizing the practical application of anion exchange membrane fuel cells. In this work, we develop a novel blend AEM incorporating polymer of intrinsic microporosity (PIM). PIM features highly rigid backbone and loose packing so that the resultant blend AEM containing PIM possesses increased free volume so that the ion clusters formed by microphase separation may get easily percolated and form pathways for hydroxide ion transport. The blend AEM containing 30% PIM shows a low ion exchange capacity (IEC) of 0.77 mmol g−1, but a relatively high conductivity of 16.9 mS cm−1 at 30 °C, and yields a H2/O2 fuel cell power density of 163 mW cm−2 at 60 °C. The membrane also shows a high mechanical robustness (tensile strength 43 MPa) and alkaline stability as compared with that without PIM incorporation. To the best of our knowledge, this work is the first report of PIM incorporation in blend AEM, and provides a new and effective strategy to promote hydroxide ion conduction in AEMs at relatively low IEC, which may pave the way to achieve better balanced conductivity and stability.