Synergistic functionalization of poly(p-terphenyl isatin) anion exchange membrane with quaternary ammonium and piperidine cations for fuel cells†

Research on anion exchange membrane fuel cells (AEMFCs) mainly focuses on the membrane module, and improving its performance has always been the focus of researchers. To create high-performance anion exchange membranes (AEMs), a series of side chain type AEMs were prepared by introducing different proportions of side chains containing anisotropic poly cations with relatively stable piperidinium ring cations and side quaternary ammonium cations as cation groups, using poly(p-terphenyl isatin) (PTI), a main chain polymer without aryl ether bonds. The dense surface of the PTI-N-n series membranes is shown by SEM images; TEM images show that the ion domains are clearly distributed in the membrane, so a continuous ion transport channel is constructed. PTI-N-100 has the highest hydroxide conductivity at 80 °C, reaching 96.83 mS cm⁻¹ due to multiple transport sites. The PTI-N-100 membrane has a peak power density of 180 mW cm⁻² based on the highest ionic conductivity. Therefore, we believe that the introduction of multi-cations contributes to the performance of anion exchange membranes.

Keywords: Multi-cation; Ether-free polymer; Alkaline resistance; Microphase separation.