Performance of Phosphonated Hydrocarbon Ionomer in the Fuel Cell Cathode Catalyst Layer
2013 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 160, no 3, F269-F277 p.Article in journal (Refereed) Published
Inexpensive and environmentally friendly electrolyte polymers that can be operated at higher temperatures and drier conditions are highly interesting for PEM fuel cells for automotive, portable power and stationary electricity generation applications. In this study an ionomer based on polysulfone grafted with poly(vinylphosphonic acid) (PSUgPVPA) in the cathode Pt/C catalyst layer was electrochemically characterized and compared to Nafion. The performance at different levels of humidity at 80 degrees C was evaluated by polarization measurements, cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The results show that the performance of the PSUgPVPA-based cathode catalyst layer is comparable to that of Nafion-at 100% relative humidity (RH) but with some instabilities. However, at drier conditions significant losses of performance for the PSUgPVPA-based cathode was observed. This could be an effect of catalyst poisoning by the ionomer interfering with ORR. However, the concomitant decrease of the electrochemical surface area, double layer capacitance and increased imaginary impedance, indicate that the poorer performance at low humidity is mainly an effect of reduced catalyst wetting by the ionomer in combination with the decreased proton conduction in the ionomeric phase.
Place, publisher, year, edition, pages
2013. Vol. 160, no 3, F269-F277 p.
Gas-Diffusion Electrodes, Mass-Transport Limitations, Proton-Exchange Membranes, Pefc Cathode, Poly(Vinylphosphonic Acid), Intermediate Temperature, Transient Techniques, Relative-Humidity, Protogenic Group, Side-Chains
IdentifiersURN: urn:nbn:se:kth:diva-119754DOI: 10.1149/2.046303jesISI: 000315307500044ScopusID: 2-s2.0-84875455943OAI: oai:DiVA.org:kth-119754DiVA: diva2:612483
QC 201303222013-03-222013-03-212016-04-18Bibliographically approved