Robust and durable poly(aryl-co-aryl piperidinium) reinforced membranes for alkaline membrane fuel cells

Abstract

Robust and durable anion exchange membranes are crucial for cost-effective anion exchange membrane fuel cells (AEMFCs). Herein, we report high-performance poly(aryl-co-aryl piperidinium) (c-PAP) reinforced membranes with >95% visible light transmittance and a typical three-layer cross-sectional morphology for AEMFCs. Importantly, the reinforced composite membranes (RCMs) simultaneously possess ultrahigh tensile strength (TS, ∼114 MPa) and elongation at break (EB, ∼159%), which are improvements over the best-performing AEMs previously reported (mostly below 50 MPa of TS and 30% of EB). Additionally, the RCMs exhibit exceptional gas tightness (H₂ crossover current density <0.2 mA cm⁻² at 20% relative humidity (RH) and H₂ permeability <10 Barrer), dimensional stability, and mechanical durability during RH cycling and pressure differential tests at 80 °C. Moreover, the RCMs maintain excellent mechanical and chemical durability after AEMFC testing at a current density of 0.6 A cm⁻² at 70 °C for ∼360 h. The present RCM is an excellent candidate for alkaline energy device applications.