Increased Efficiency and Performance of Electrolyzer Systems Through Bubble-free Electrolysis

Electrolysis is a key component of the future hydrogen economy. Low production costs for hydrogen are a prerequisite for market penetration and rapid transformation. The manufacturing costs for electrolysers and their operating costs are key cost drivers in this regard. Bubble-free electrolysis promises to reduce energy consumption by up to 15% compared to proton exchange membrane (PEM) electrolysis. PEM electrolysis uses a solid polymer electrolyte—the proton exchange membrane—which is surrounded by water. When an electrical voltage is applied to the membrane, protons migrate through the membrane: hydrogen is produced at the cathode and oxygen at the anode.

The realization of bubble-free electrolysis represents a significant contribution to the efficiency and performance improvement of electrolyzer systems, as the mass transport losses and performance limitations caused by bubble formation are avoided. The proposed approach of a novel hollow fiber-reinforced membrane also offers the possibility of significant cost reduction through the simplified design of the electrolysis system and lower degradation of the individual components, which is of great importance for the effective market ramp-up of the hydrogen economy.

The project therefore aims to verify the functional principle and identify technical hurdles to scaling up. To this end, a demonstrator for an electrolysis cell with a hollow fiber composite membrane for bubble-free electrolysis will be developed and constructed. This demonstrator will be used to test the design and operating principle of the novel concept. To this end, hollow fibers will first be procured and laboratory tests will be carried out for their incorporation into a PEM membrane, e.g., by lamination or embedding in a casting process. The membrane containing the hollow fibers will be coated with catalyst material. In a small electrolysis test cell developed specifically for this purpose, water is then fed through the hollow fibers from the inside of the membrane. The aim is to demonstrate the electrolysis function when water is fed through the hollow fibers. The efficiency is compared with the hydrogen production when the cell is operated in a conventional cell design with water feed from the anode side.