Construction of crosslinked polybenz imidazole-based anion exchange membranes with ether-bond-free backbone.

In order to develop anion exchange membranes (AEMs) with high ionic conductivity, low swelling ratio (SR) and long-term alkaline stability, a series of crosslinked polybenzimidazole-based AEMs (FPBI-QPVC x) were prepared. We herein demonstrated that the integration of a partially fluorinated polybenzimidazole and quaternized poly(vinylbenzyl chloride) benefits the fabrication of the AEMs with well-defined hydrophilic/hydrophobic phase-segregated structure, leading to a relative high hydroxide conductivity of 91.7 mS cm−1 at 80 °C for FPBI-QPVC 2.5. The existence of a crosslinking structure endowed the as-prepared AEMs with relatively low water uptake and SR. Besides, the FPBI-QPVC x AEMs also have robust mechanical properties, high thermal decomposition temperature and good alkaline stability. Only 10.7% of conductivity loss was observed after soaking the ether-bond-free AEMs into 1 M a.q. KOH at 80 °C for 480 h. A maximum power density of 197.5 mW cm−2 was determined by a single cell using FPBI-QPVC 2.5 AEM. Image 1 • Novel crosslinked polybenzimidazole-based AEMs were prepared. • The AEMs exhibited well-defined micro-phase separation structures. • The crosslinking structure constrained the water swelling behavior of the AEMs. • The ether-bond-free backbone improved the alkaline stability of the AEMs. • The highest conductivity of 91.7 mS cm−1 was obtained. [ABSTRACT FROM AUTHOR]