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

Abstract

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 960h of immersion at 60°C in 1M NaOH aqueous solution. The maximum peak power density of the single cell based on PC-PF-QA is 214mW cm-2 at 60°C.