Validation and characterization of suitable materials for bipolar plates in PEM water electrolysis

• Published in: International journal of hydrogen energy Vol. 40; no. 35; pp. 11385 - 11391
• Main Authors: Langemann, Manuel, Fritz, David L., Müller, Martin, Stolten, Detlef
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 21.09.2015
• Subjects: Bipolar plates; Characterization methods; PEM water electrolysis; pH value; Real operating environment; Characterization methods; Real operating environment; pH value; PEM water electrolysis; Bipolar plates
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2015.04.155

The polymer electrolyte membrane (PEM) electrolysis cell is a promising prospect for the production of clean hydrogen by energy of renewable wind and solar sources. One component of the PEM electrolyzer is the bipolar plate (BPP), which serves as a multi-function component during PEM water electrolysis. Titanium is typically regarded as the state-of-the-art material. Mechanically it could potentially be replace by lower-cost materials such as stainless steel, but under the harsh environmental conditions present in PEM water electrolysis, stainless steel is not corrosion-resistant and metal ions can dissolve. In this case metal ions would poison the catalyst and membrane, which leads to a reduction in the cell performance [1]. We have tested several coatings such as Au and TiN in PEM water electrolysis environments of varying severity for the application as a protective layer of bipolar plates. In order to determine possible candidates for a long-term test under real simulated PEM water electrolysis conditions, an experiment to determine pH value in PEM water electrolysis operation was developed to obtain the required pH value for the ex-situ testing of various coating materials. •We have determined the development of the pH value of an operating PEM water electrolysis cell.•The pH value dropped down within an initial phase of 50 h in a recirculating measurement setup.•The pH value has a significantly influence to the degradation of substrate and coating materials for bipolar plates.•A coating without defect spots is essential for high protection of the base material.