Chemically & physically stable crosslinked poly(aryl-co-aryl piperidinium)s for anion exchange membrane fuel cells

Poly(aryl-co-aryl piperidinium) (c-PAP) copolymers have recently demonstrated great successes in anion exchange membranes (AEMs) and ionomers for AEM fuel cells (AEMFCs). Here, we present a series of in-situ styrene-crosslinked c-PAP (x-PAP-PS) membranes to further enhance the mechanical strength, dimensional stability, and water retention capacity of c-PAP AEMs. Specifically, x-PAP-PS AEMs simultaneously possess high ion conductivity (>150 mS cm(-1)), tensile strength (>80 MPa), and chemical and mechanical durability (similar to 90 % ion conductivity and mechanical strength maintaining in 1 M NaOH at 80 degrees C for 2160 h). Additionally, x-PAP-PS-based AEMFCs reached peak power densities (PPDs) of 2.23 W cm(-2) in H-2-O-2 and 1.32 W cm(-2) in H-2-air at 80 degrees C. Importantly, compared to pristine c-PAP AEMs, x-PAP-PS AEMs display higher water retention capacity at low relative humidity (RH), and the corresponding AEMFCs reach PPDs >1 W cm(-2) with Pt/C at 30 %/30 % RH at 90 degrees C. Moreover, the x-PAP-PS-based AEMFCs can be operated stably under a 0.4 A cm(-2) current density at 60 degrees C for similar to 120 h.

Automated summary

The in-situ styrene-crosslinked c-PAP (x-PAP-PS) membranes exhibit high ion conductivity, mechanical strength, and durability, maintaining stability under harsh conditions. These membranes show improved water retention capacity at low relative humidity and achieve high power densities in AEMFCs.