Advanced Patterned Membranes for Efficient Alkaline Membrane Electrolyzers

Rational design of membrane electrode assemblies is crucial to the production of high-performance and durable anion exchange membrane (AEM) water electrolyzers (AEMWEs). Here, we propose a facile method to prepare patterned membranes by casting a polymer solution onto the surface of commercially available monocrystalline silicon plates with pyramid-shaped patterns on their surface. The prepared membrane shows a 39% improvement in water permeability and a 23% enhancement in the electrochemical surface area compared with a flat membrane with the same catalyst loading. The patterned AEM achieves an unprecedented current density of 17.5 A cm–2@2.0 V and mass activity of 26.3 A mgIrO2–1 using a catalyst-coated membrane method. Moreover, the patterned AEM-based AEMWE can be operated at 1.5 A cm–2 and 60 °C for 1000 h with a relatively low voltage decay rate of 22 μV h–1. These results demonstrate that patterned membranes have promising application capability for the next generation of hydrogen-production devices.