Bipolarplattenmaterialien für Polymer-Elektrolyt-Membran Elektrolyse

The intention to reduce Germany's CO2 emissions over the long term will be fosterned by the expansion of renewable energy sources, such as wind power. Since the network coverage of such systems is strongly dependent on weather conditions and will therefore entail fluctuation in their energy supply, it will be necessary to integrate suitable storage systems so that potential bottlenecks in the electricity supply may be bridged. One storage option is the generation of hydrogen, which can be conducted by means of using renewable power to drive water electrolysis. Due to its dynamic operation mode, the polymer electrolyte membrane (PEM) electrolysis is particularly suitable, because it can react rapidly to varying input capacities. The challenges in this field of research are, in particular, to selectively reduce the investmentcosts of PEM electrolyzers by using more cost-effective alternative materials withoutlosing cell performance. This work investigates of commercially available materials that can primarily be used due to their suitability as bipolar plate material in PEM water electrolysis. The aim is to identify alloysthat are stable in the long term, or material combinations that are characterized by low corrosion with good electrical contact properties. An evaluation of the corrosion that develops is carried out by using the experimental investigations in outsourcing corrosion and single cell tests through analysis of the metal ion emission, as well as the increase in contact resistance that results from the strain, influenced by the cell potential, temperature and pH value of the operating water. Using both analytical electric and electrochemical methods, the selection of possible substrate and coating materials could be limited to a few metals within the PSE. Subsequentcontinuous and long-term tests under real PEM electrolysis conditions have shown that a combination of stainless steel substrate and a thin gold layer already results in significantly lower metal ion emissions and virtually no increase in contact resistance compared to the benchmark