Experimental characterization of internal currents during the start-up of a proton exchange membrane fuel cell

• Published in: Journal of power sources Vol. 196; no. 22; pp. 9451 - 9458
• Main Authors: Lamibrac, A., Maranzana, G., Lottin, O., Dillet, J., Mainka, J., Didierjean, S., Thomas, A., Moyne, C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2011; Elsevier
• Subjects: Applied sciences; Carbon; Carbon corrosion; Damage; Direct energy conversion and energy accumulation; Electric power; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Engineering Sciences; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Flow rate; Fuel cells; Hydrogen flow rate; Internal currents; Membranes; Modelling; Oxidation; PEM fuel cells start-up; Segmented cell; Segments; Shutdowns; Internal currents; Segmented cell; PEM fuel cells start-up; Modelling; Carbon corrosion; Hydrogen flow rate; Polymer electrolytes; Hydrogen; Polymer solid electrolyte; Carbon; Modeling; Corrosion; Starting; Proton exchange membrane fuel cells
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.07.013

► Local current densities were used to estimate carbon oxidation during PEMFC start-up. ► Start-ups under air and nitrogen were compared to isolate carbon oxidation currents. ► Oxidation of carbon is higher when hydrogen flow rate is lower. ► Local EIS confirms degradations in H 2 outlet for start-up by injection of H 2 in air. ► These results allow improving carbon oxidation models and protocols for start-ups. Start-up/shutdown under inappropriate conditions are known to damage proton exchange membrane fuel cells. Several measurement techniques were already used to characterize their effects and the degradations are mainly attributed to carbon oxidation: a decrease of the cathode active area is commonly observed after start-up/shut-down cycles. In order to achieve a better understanding of the conditions in which this phenomenon appears, a segmented cell was designed and internal currents were recorded during start-up under open circuit conditions. The results of this work allow estimating the carbon losses at a global, as well as at a local scale, as a function of the hydrogen flow rate. Local electrochemical impedance spectroscopy measurements carried out on damaged MEA show clearly that the segments that remain for the longest time in the presence of air (while the others are fed by hydrogen) are the most affected by carbon oxidation.