Perfluorinated Anion Exchange Membranes for Alkaline Water Electrolysis

Anion exchange membranes (AEMs) have been getting great attraction in the field of alkaline water electrolysis because of their excellent barrier properties to hydrogen and oxygen. Here, we synthesized a perfluorinated AEM ionomer via one-step polycondensation reaction of a perfluorinated sulfonyl fluoride (PF-SO2F) precursor with the chemical architecture identical to Nafion® using N-phenylhydroxylamine (HPA). The synthesized NR-HPA ionomer was homogenously dispersed in an aqueous alcohol media via a supercritical fluid technique for AEM fabrication. The resulting AEM membrane has high OH- conductivity (e.g., 81 mS cm-1 at 90oC) and excellent chemical durability (e.g., ~200 hours at 80oC) even at the elevated temperatures. The electrochemical single cell performance was comparable to that of the state-of-the art alkaline membrane Zirfon® in the same measurement condition of 2 M KOH at 80oC.