Facile preparation of porefilled membranes based on poly(ionic liquid) with quaternary ammonium and tertiary amine head groups for AEMFCs

Abstract

Ionic liquid with quaternary ammonium and tertiary amine head groups is obtained by adding 4-vinylbenzylchloride (VBC) into tetramethylethylenediamine (TMEDA) drop by drop in the ice water bath. The ionic liquid is polymerized at 100 °C with porous polyethylene (PE) membrane as the substrate, resulting in a porefilled anion exchange membrane. After soaking in 1 M KOH solution for 48 h, an alkaline anion exchange membrane is obtained. The conductivity of the membrane is 32.8 mS/cm at 60 °C and is stable in 1 M KOH for >350 h. And the tensile strength at break is >80 MPa with a swelling rate of about 26.7%. The water permeability is also improved, mostly because the tertiary amine head groups afford extra water transport channels. The half-cell tests show that the ionic liquid monomer ruins the activity of Pt/C catalyst, while after polymerizing the ionic liquid and washing the resulted AEM for several times, the AEM do not poison the catalyst any more. The peak power density of the single cell using this membrane reaches 545 mW/cm2 at 1000 mA/cm2.