Piperidinium-Based Anion-Exchange Membranes with an Aliphatic Main Chain for Alkaline Fuel Cells

A series of cross-linked piperidinium-based anion-exchange membranes (AEMs) with an aliphatic main chain was prepared by UV-initiated polymerization of 1-methyl-1-(4-vinylbenzyl)piperidinium chloride ([MVBPip][Cl]). The chemical structures of [MVBPip][Cl] and piperidinium-based membranes were studied by nuclear magnetic resonance (NMR) and IR spectroscopy, respectively. The piperidinium cation showed excellent alkaline stability, demonstrated by 1H NMR spectroscopy. The water uptake and conductivity of the piperidinium-based AEMs were enhanced by an increase in [MVBPip][Cl] content. A hydrophilic/hydrophobic microphase-separated structure was clearly detectable in the piperidinium-based AEMs. The transparent and mechanically robust piperidinium-based AEMs exhibited excellent chemical stability in 2 M KOH solution with the conductivity reaching 57.4 mS cm–1 (80 °C). The maximum power density of the single cell fabricated with piperidinium-based AEMs achieved 108.8 mW cm–2. These results indicate that the cross-linked piperidinium-based AEMs with an aliphatic main chain are promising materials for application in fuel cells.