Thermally Sprayed Low Cost Current Collectors with Optimized Mass Transport Behavior for PEM Electrolyzers

Kurzfassung

The costs of the Proton Exchange Membrane (PEM) electrolyzer system need to be reduced while maintaining high performance. The stack component costs comprise 60% of the total system costs in which the bipolar plates and the current collectors are the main factors. In this thesis the facts that current collectors are produced by Vacuum Plasma Spraying (VPS) are discussed and described and are characterized physically as well as electrochemically. The developed graded structures exhibit improved properties regarding conductivity and water transport. The optimal structures for the layer contacting the electrode have pore diameters between 6 and 17um and porousness between 17 and 30%. X-Ray scanning tomography (performed at the University of Toronto) enables 3D reconstructions of the samples confirming the porosity and pore distribution. Moreover, a model in OpenPNM was used to predict the movement of the gases through the current collectors.