Alkaline anion exchange membrane containing pyrene-based π-π stacking interactions

Highly conductive and chemically resistant alkaline anion exchange membranes (AAEMs) are highly desirable in various electrochemical devices such as alkaline anion exchange membrane fuel cells (AAEMFCs) and water electrolysis. Here we present the novel AAEMs with pyrene-containing ether-free polymer backbones bearing piperidinium cations. Both morphology analyses and simulations verify that the π-π stacking of pyrene units in polymer backbones can actuate the neighboring piperidinium cations to aggregate and form ion conducting channels, thus enhancing the ion conductivity of AAEMs (153 mS cm −1 at 90 °C). Additionally, the resultant aryl ether-free poly(aryl piperidinium) structure guarantees the chemical durability of the AAEMs, which has 91.5% OH − conductivity retention after treatment in 2 M NaOH at 80 °C for1080 h. Meanwhile, the rigid pyrene units increase the rigidity of polymer backbones, resulting in excellent mechanical strength (46.3 MPa) and dimensional stability (swelling ratio of 11.8% at 90 °C). The molecular design provides an attractive strategy for advancing the development of high-performance AAEMs. •The pyrene-containing poly(aryl piperidinium) was designed for AAEM. • The π-π stacking between pyrene units induces aggregation to form ion channels. • Intra-membrane ion channels significantly improve ion conductivity. • The prepared AAEM shows improved H 2 /O 2 fuel cell performance and durability.