Aromatic polyelectrolytes via polyacylation of pre-quaternized monomers for alkaline fuel cells†

To overcome alkali-resistant and synthetic hurdles to alkaline anion-exchange membranes (AAEMs) for alkaline fuel cells, the polyacylation of pre-quaternized monomers as a straightforward and versatile approach has been proposed for the first time. Via this approach, novel aromatic anion-exchange polyelectrolytes featuring a long pendent spacer (i.e., –O–(CH2)4–) instead of a conventional benzyl-type spacer (i.e., –CH2–) are successfully synthesized, and exhibit not only high OH and CO3 2 conductivity (91 mS cm 1 and 51 mS cm 1 at 60 C, respectively) but also outstanding alkaline stability (e.g., no degradation of ammonium groups after aging in 6 mol dm 3 NaOH at 60 C for 40 days). Using this kind of AAEM, a promising peak power density of 120 mW cm 2 is obtained on a preliminary H2/O2 single cell at 50 C. This powerful synthetic approach together with exceptional membrane properties should pave the way to the practical application of this kind of AAEMs in alkaline fuel cells.