Novel π-π stacked poly(aryl-piperidine) anion exchange membranes with excellent stability for fuel cells

Abstract

Anion exchange membrane fuel cells (AEMFCs) have attracted much attention due to their advantages of being green, inexpensive and efficient. However, as the key to AEMFCs, anion exchange membranes (AEMs) still face challenges in balancing ionic conductivity and dimensional stability, limiting their application in fuel cells. In response, we report here an AEM strategy based on phenanthrene π-π stacking. The phenanthrene in the polymer backbone drives self-aggregation of cations to widen ionic transport channels, achieving a high ionic conductivity of 136.06 mS cm⁻¹ and a low swelling ration of 19.37 % at 80 °C. Moreover, the as-prepared AEMs retained 96.2 % conductivity after immersion in 2 M NaOH solution at 80 °C for 1400 h, demonstrating excellent alkali stability. In addition, the developed novel AEM demonstrated a peak power density of 452.88 mW cm⁻² in single fuel cells and a voltage drop of only 3.82 % after 50 h in-situ durability testing, highlighting the significant potential for wider application in fuel cells.