Novel Fluorinated Anion Exchange Membranes Based on Poly(Pentafluorophenyl‐Carbazole) with High Ionic Conductivity and Alkaline Stability for Fuel Cell Applications

Constructing good microphase separation structures by designing different polymer backbones and ion‐conducting groups is an effective strategy for improving the ionic conductivity and chemical stability of anion exchange membranes (AEMs). In this study, a series of AEMs based on the poly(pentafluorophenylcarbazole) backbone grafted with different cationic groups are designed and prepared to construct well‐defined microphase separation morphology and improve the trade‐off between the properties of AEMs. Highly hydrophobic fluorinated backbone and alkyl spaces enhance phase separation and construct interconnected hydrophilic channels for anion transport. The ionic conductivity of the PC‐PF‐QA membrane is 123 mS cm−1 at 80 °C, and the ionic conductivity of the PC‐PF‐QA membrane decreased by only 6% after 960 h of immersion at 60 °C in 1 M NaOH aqueous solution. The maximum peak power density of the single cell based on PC‐PF‐QA is 214 mW cm−2 at 60 °C. Novel poly(pentafluorophenylcarbazole) polymers are catalytically prepared using trifluoroacetic acid. Highly hydrophobic fluorinated backbone and alkyl spaces enhance phase separation and construct interconnected hydrophilic channels for anion transport. Different polymer backbones and ion‐conducting groups are designed to construct good microphase separation structures while improving the ionic conductivity and chemical stability of anion‐exchange membranes.