High-Performance Anion Exchange Membranes with π-π Stacking and Hydrogen Bonding Bifunctional Units.

Strong intermolecular interactions facilitate the formation of efficient ion transport channels, which, in turn, significantly boost the performance of anion exchange membranes (AEMs). Herein, 9-anthracene methanol with both π-π stacking and hydrogen bonding intermolecular forces is used as a bifunctional unit to synthesize high-performance AEMs through the Friedel-Crafts superacid catalytic reaction for the first time. The π-π stacking in the bifunctional units can induce hydrophilic pyridine cations to aggregate, and the hydrogen bonding can provide transport sites for OH and water molecules in the hydrophobic component. They collaborate to build long-range ordered ion channels. Therefore, the prepared membrane QPHANPD-20 exhibits an extremely high conductivity of 173.18 mS/cm at 80 °C. In addition, the QPHANPD-20 AEM exhibits excellent alkali resistance: after soaking in 3 mol/L KOH solution at 80 °C for 1440 h, the OH conductivity retention rate remains as high as 90.8%. Furthermore, the fuel cell based on QPHANPD-20 exhibits superior power density (1.771 W/cm at 80 °C) and durability: at a current density of 0.4 A/cm, it only shows a voltage drop of 0.082 V after 180 h of operation. This study proposes a strategy for synthesizing high-performance AEMs based on dual functional units of π-π stacking and hydrogen bonding, which further enhances the application value of AEMs in fuel cells.