74 µm PEEK‐Reinforced Sulfonated Poly(phenylene sulfone)‐Membrane for Stable Water Electrolysis with Lower Gas Crossover and Lower Resistance than Nafion N115
Regina Qelibari, Edgar Cruz Ortiz, Niklas van Treel, Florian Lombeck, Clara Schare, Andreas Münchinger, Nodar Dumbadze, Giorgi Titvinidze, Carolin Klose, Severin Vierrath
Abstract
Abstract Polymer electrolyte membrane (PEM) water electrolysis is a crucial technology for green hydrogen production. Hydrocarbon membranes are drawing a lot of attention due to potentially superior properties and the fact that common fluorinated polymers might face a potential ban. This study introduces a sulfonated poly(phenylene sulfone) (sPPS) membrane, reinforced with a poly(ether‐ether‐ketone) (PEEK) mesh. The reinforced membrane induces a drastic increase in dimensional stability, enabling direct anode casting—an essential step toward industrial manufacturing. It further exhibits a significant reduction in water uptake (115% vs 294% for pure sPPS) and a 40% lower H 2 ‐crossover (0.18 mA cm −2 ) compared to the industry standard N115 (0.31 mA cm −2 ). Due to the lower thickness (74 vs 127 µm) and higher ion exchange capacity (IEC)(1.92 vs 0.89 mmol g −1 ), the PEEK‐sPPS membrane displays a substantially lower resistance (70 vs 159 mΩ cm 2 for N115). This directly translates into a voltage reduction of ≈90 mV at 1 A cm −2 or ≈180 mV at 2 A cm −2 , both typical operating current densities. Finally, PEEK‐sPPS exhibits the longest lifetime shown for hydrocarbon membranes with almost 650 h at 1 A cm −2 and a low degradation rate (80 µV h −1 ).