Anion exchange membrane using poly(ether ether ketone) containing imidazolium for anion exchange membrane fuel cell (AEMFC)

In this study, PEEKs with different contents of imidazolium group (DI-PEEK) were synthesized by facile condensation polymerization using bisphenol A, 2,2′-di(2-ethyl-methylimidazole-methylene)-4,4′-dihydroxydiphenylether and difluorobenzophenone. Highly flexible and transparent DI-PEEK membranes showing anion exchange behavior could be prepared by the DI-PEEK solution using DMAc as a solvent. The DI-PEEK membrane with optimized content of imidazolium group (30 mol%) showed the highest ion conductivity (78 mS/cm at 80 ℃) without deterioration of thermal and mechanical stability among the samples. A membrane electrode assembly using the DI-PEEK membrane with optimized content of imidazolium group revealed comparable cell performance (98 mW/cm2 at 0.43 V) to that using a commercialized anion exchane membrane (114 mW/cm2 at 0.43 V) under operating conditions of 60 ℃ and 100% RH.