High Performance AEM Water Electrolysis with Aemion® Membranes

Abstract

By 2030 up to 50% of energy is expected to be carried in the bonds of H2. Global electrolysis capacity must increase from the current 240 MW to an anticipated 300 GW in 2030 and 3500 GW in 2050 to enable this transition. Alkaline and PEM electrolyzers are commercially mature with the currently market share of new installations roughly an equal split between these technologies. However, each of these electrolyzers are associated with challenges – alkaline electrolyzers operate at low current density, and require high concentration electrolytes (30 wt% KOH) to conduct hydroxides through the porous electrode separator (I.e., Zirfon). PEM electrolyzers use a proton conductive membrane to enable high current densities, however, running the reaction in acidic electrolyte requires platinum group catalysts and component coatings that hinder scalability at 2050 targets.AEM water electrolyzers address both of these challenges by pairing anion exchange membrane with alkaline electrolyte to enable high current density operation, at high pressure, without noble metal catalysts. These attributes enable the most cost-effective green hydrogen - bringing the DOE hydrogen shot target of $1/kg within reach.Anion exchange membrane chemistries have previously hindered this type of electrolyzer – AEMs based on quaternary amines, or pendant imidazolium groups chemically degrade in concentrated alkaline electrolyte, and mechanically degrade (from swelling) in low concentration alkaline media. Ionomr’s Aemion+ membranes are based on a sterically-protected polybenzimidazole chemistry and are chemically robust (stable in up to 10 M KOH), and exhibit low swelling to enable operation in low concentration electrolytes. These membranes are an enabling technology for long duration water and CO2 electrolysis.This talk highlights how Ionomr’s Aemion+ membranes enable performance in excess of 1 A/cm2 at 1.8 V with non-PGM catalysts and a variety of configurations, and >4000 hours of durability in continuous operation. Figure 1