Speaker
Dr
Oxana Ivanova
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Description
Proton conducting polymer electrolyte membranes, in particular, commercially available polybenzimidazole (PBI) attract increasing interest for high-temperature polymer electrolyte fuel cells (HT-PEFC) operating at 160-180°C. HT-PEFC are promising energy converters for stationary (e.g. based on natural gas reforming and combined heat generation) and mobile applications, such as auxiliary power units due to their high tolerance for fuel impurities, i.e. CO and environmentally friendly operation (water as by-product of electrochemical reaction) [1]. Excellent thermal and chemical stability of PBI-based membranes in combination with sufficient conductivity after impregnation with phosphoric acid (PA), which has the highest known intrinsic proton conductivity, assures sufficient conductivity of the these membranes.
In order to get a better understanding of the crucial parameters of the HT-PEFC, e.g. its conductivity and overall performance, structural features of PBI-based membranes have been investigated on the length scales ranging from sub-nm up to several micrometers [2]. Different scattering and imaging techniques such as X-ray diffraction (XRD), neutron diffraction with polarization analysis, small angle neutron- and X-ray scattering (SANS and SAXS respectively), polarized light- and transmission electron microscopy (TEM) have been used. Impact of the temperature changes as well as aging effects will be discussed. Obtained results are linked to proton diffusion measured over a wide time scale by means of pulsed-filed-gradient nuclear magnetic resonance PFG NMR and neutron spectroscopy [3] as well as macroscopic parameters of the fuel cell.
References:
[1] In “Polymers for PEM Fuel Cells”, ed. H. Pu, John Wiley Press, 2014
[2] O. Ivanova et al., submitted to Soft Matter
[3] B. Hopfenmüller, in preparation
Primary author
Dr
Oxana Ivanova
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Co-authors
Mr
Bernhard Hopfenmüller
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Dr
Kirill Nemkovskiy
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Dr
Margarita Krutyeva
(JCNS Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH)
Dr
Marie-Sousai Appavou
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Dr
Michael Monkenbusch
(JCNS Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH)
Dr
Noemi Szekely
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Olaf Holderer
(Jülich Centre for Neutron Science (JCNS), outstation at MLZ, Forschungszentrum Jülich GmbH)
Dr
Reiner Zorn
(Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich)
Prof.
Werner Lehnert
(Institut für Energie- und Klimaforschung (IEK), Forschungszentrum Jülich GmbH & RWTH Aachen University, Faculty of Mechanical Engineering)
Dr
Wiebke Lüke
(Institut für Energie- und Klimaforschung (IEK), Forschungszentrum Jülich GmbH)
