Direct membrane deposition as novel fabrication technique for high performance fuel cells

Hochschulschrift

Abstract: In this thesis, a novel fabrication technique for membrane-electrode assemblies for polymer electrolyte membrane fuel cells (PEMFC) is developed. The conventionally employed membrane foil is replaced by two thin ionomer layers, which are deposited onto gas diffusion electrodes of both anode and cathode side of the fuel cell. This process was introduced in literature as ‘direct membrane deposition’ (DMD). The present thesis summarizes the full process development from a simple, inkjet-printed ionomer membrane towards a multicomponent composite membrane, resisting to state-of-the-art degradation tests. In particular three results of this work contributed significantly to the development of novel PEMFC components:
- DMD was employed to yield the highest Platinum utilization efficiency, published in the current academic state of the art. By applying DMD to gas diffusion electrodes with very low Pt-loadings of up to 0.029 mg/cm² a cathodic Pt-utilization efficiency of more than 88 kW/gPt was reached, outperforming the best value in literature (70 kW/gPlatinum) by about 20 %.
- By the means of in-situ neutron radiographies at the ANTARES beamline in the neutron source FRM-II in Garching, it was possible to show that in DMD fuel cells, significant amounts of water diffuse from the cathode to the anode, in spite of dry operation conditions. This confirmed assumptions based on impedance spectroscopy measurements, that the improved membrane│electrode interface in DMD fuel cells significantly improves the water management.
- By combining electrospinning and inkjet-printing, the first directly deposited composite membranes were produced in this work, enabling elevated operation temperatures up to 120 °C. Moreover, by decorating these electrospun nanofibers with radical-scavenging cerium oxide nanoparticles, the degradation stability of the membranes could be significantly enhanced: In comparison to a comparably thin, reinforced membrane of the state of the art, a three times lower degradation rate could be reached in an accelerated stress test

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch
• Anmerkungen: IN COPYRIGHT http://rightsstatements.org/page/InC/1.0 rs ; Albert-Ludwigs-Universität Freiburg, Dissertation, 2017

Klassifikation und Themen

• Klassifikation: Elektrotechnik, Elektronik
• Schlagwort: Polymer-Elektrolytmembran-Brennstoffzelle

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2017
• Urheber: Breitwieser, Matthias
• Beteiligte Personen und Organisationen: Zengerle, Roland ; Albert-Ludwigs-Universität Freiburg. Institut für Mikrosystemtechnik ; Albert-Ludwigs-Universität Freiburg. Fakultät für Angewandte Wissenschaften ; Albert-Ludwigs-Universität Freiburg

Weitere Informationen

• DOI: 10.6094/UNIFR/13444
• URN: urn:nbn:de:bsz:25-freidok-134440
• Rechteinformation: Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:44 MEZ