TY - JOUR A1 - Rost, Ulrich A1 - Wirkert, Florian Josef A1 - Roth, Jeffrey A1 - Brodmann, Michael A1 - Stiber, Svenja A1 - Saul Gago, Aldo A1 - Friedrich, Kaspar Andreas T1 - A novel advanced test system for polymer electrolyte membrane water electrolysis based on hydraulic cell compression JF - Fuel Cells, Band 22, Ausgabe 6 N2 - In this work, a novel polymer electrolyte membrane water electrolyzer (PEMWE) test cell based on hydraulic single-cell compression is described. In this test cell, the current density distribution is almost homogeneous over the active cell area due to hydraulic cell clamping. As the hydraulic medium entirely surrounds the active cell components, it is also used to control cell temperature resulting in even temperature distribution. The PEMWE single-cell test system based on hydraulic compression offers a 25 cm2 active surface area (5.0 × 5.0 cm) and can be operated up to 80°C and 6.0 A/cm2. Construction details and material selection for the designed test cell are given in this document. Furthermore, findings related to pressure distribution analyzed by utilizing a pressure-sensitive foil, the cell performance indicated by polarization curves, and the reproducibility of results are described. Experimental data indicate the applicability of the presented testing device for relevant PEMWE component testing and material analysis. KW - novel KW - polymer electrolyte membrane KW - water electrolysis KW - hydraulic cell compression Y1 - 2022 U6 - https://doi.org/10.1002/fuce.202200068 SP - 284 EP - 289 ER - TY - JOUR A1 - Kellenberger, Andrea A1 - Vaszilcsin, Nicolae A1 - Duca, Delia A1 - Dan, Mircea Laurentiu A1 - Duteanu, Narcis A1 - Stiber, Svenja A1 - Morawietz, Tobias A1 - Biswas, Indro A1 - Ansar, Syed Asif A1 - Gazdzicki, Pawel A1 - Wirkert, Florian Josef A1 - Roth, Jeffrey A1 - Rost, Ulrich A1 - Brodmann, Michael A1 - Saul Gago, Aldo A1 - Friedrich, Kaspar Andreas T1 - Towards Replacing Titanium with Copper in the Bipolar Plates for Proton Exchange Membrane Water Electrolysis JF - Materials 2022, 15(5), 1628 N2 - For proton exchange membrane water electrolysis (PEMWE) to become competitive, the cost of stack components, such as bipolar plates (BPP), needs to be reduced. This can be achieved by using coated low-cost materials, such as copper as alternative to titanium. Herein we report on highly corrosion-resistant copper BPP coated with niobium. All investigated samples showed excellent corrosion resistance properties, with corrosion currents lower than 0.1 µA cm−2 in a simulated PEM electrolyzer environment at two different pH values. The physico-chemical properties of the Nb coatings are thoroughly characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). A 30 µm thick Nb coating fully protects the Cu against corrosion due to the formation of a passive oxide layer on its surface, predominantly composed of Nb2O5. The thickness of the passive oxide layer determined by both EIS and XPS is in the range of 10 nm. The results reported here demonstrate the effectiveness of Nb for protecting Cu against corrosion, opening the possibility to use it for the manufacturing of BPP for PEMWE. The latter was confirmed by its successful implementation in a single cell PEMWE based on hydraulic compression technology. KW - PEMWE KW - water electrolysis KW - bipolar plate KW - corrosion resistance KW - coatings Y1 - 2022 U6 - https://doi.org/10.3390/ma15051628 N1 - This article belongs to the Special Issue Recent Research on Energy Storage Materials: Properties and Applications. ER -