Measurement of protonic resistance of catalyst layers as a tool for degradation monitoring

• Published in: International journal of hydrogen energy Vol. 42; no. 3; pp. 1800 - 1812
• Main Authors: Gaumont, Thomas, Maranzana, G., Lottin, Olivier, Dillet, Jérôme, Didierjean, Sophie, Pauchet, J, Guétaz, L
• Format: Journal Article
• Language: English
• Published: Elsevier 17.01.2017
• Subjects: Catalysis; Chemical and Process Engineering; Chemical engineering; Chemical Sciences; Engineering Sciences; Other; Polymers; Reactive fluid environment; carbon corrosion; Electrochemical Impedance Spectroscopy; protonic resistance; catalyst layer ionic resistance; PEMFC electrode degradation; ionomer degradation
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2016.10.035

The ionic resistance of a PEM fuel cell catalyst layer, as well as the double layer capacity and the high frequency resistance are estimated from the impedance spectra of H 2 /N 2 operated cell, thanks to a volumetric electrode model. The impedance spectra are calculated in the case of a homogeneous distribution of resistivity and capacity, and considering both trough plane and in plane heterogeneities. Then, results of the degradation of a MEA submitted to four different accelerated stress tests are presented. They consist of (i) a constant current operation, (ii) 1.2V potential hold with nitrogen and hydrogen (iii) open circuit voltage (OCV) hold with air and hydrogen, and (iv) a start-up protocol where heterogeneous degradations are observed using a linear segmented fuel cell. This technique can provide useful information about the evolution of catalyst layer microstrucure during AST.