Composite anion exchange membranes based on graphene oxide for water electrolyzer applications

Abstract

Anion Exchange Membrane Water Electrolyzers (AEMWE) hold the promise of combining the advantages of both liquid alkaline and PEM technologies, offering higher purity hydrogen production, improved efficiency, and dynamic behaviour. Nevertheless, AEM systems face notable challenges, particularly in enhancing the ion conductivity and stability of the membrane. The alkaline chemical stability of the AEMs is, in particular, one of the biggest issues, giving the high alkaline solutions used as electrolyte. To overcome those problems, here in this work, the strategy chosen is the simple addition of an inorganic filler in the polymer matrix of the membrane. Various amounts of Graphene Oxide (GO), synthesized using the modified Hummers method, were incorporated into Fumion-based membranes. The resulting AEMs shows improved water uptake, chemical stability, thermal stability and, with the right amount of filler, also enhanced conductivity. In particular, all the composite membranes show diminished weight loss and I.E.C. loss after 170h in 6M KOH at 80°C. The Fumion-GO AEM with 3%GO (wt%) shows improved conductivity and a remarkable current density higher than 1 A/cm2 at 2 V and 60°C in the chronoamperometric test.