Durability and Performance of Poly(norbornene) Membranes and Ionomers in Alkaline Electrolyzers

Abstract

Ion conducting polymer electrolytes provide an enabling technology for low-temperature alkaline electrolyzers. The critical parameters of solid polymer electrolytes include ionic conductivity, ion selectivity, chemical resistance and dimensional stability in the presence of excess water. High pH operation using anion conductive polymer electrolytes has several potential advantages over acid-based polymer devices including low-cost catalysts, hydrocarbon (non-perfluorinated) polymer, and low cost cell components.In this study, a family of hydroxide conducting, poly(norbornene) solid polymer electrolytes were synthesized and used in high-performance, durable membrane electrode assemblies for fuel cells and electrolyzers. In addition to membranes, covalently bonded, self-adherent, hydroxide conducting ionomers were used to form high-performance, durable membrane electrode assembly for water electrolysis. The self-adhesive ionomers and membranes are based on hydroxide conducting poly(norbornene) polymers. The effect of porous transport layer material and porosity was examined. High performance electrolysis with very low degradation rates was achieved using stainless steel and nickel porous transport layers and flow-channels