Dynamic Operation of HT-PEFC: In-Operando Imaging of Phosphoric Acid Profiles and (Re)distribution. Issue 3 (6th January 2015)

• Record Type: Journal Article
• Authors: Eberhardt, S. H.; Toulec, M.; Marone, F.; Stampanoni, M.; Büchi, F. N.; Schmidt, T. J.
• Is Part Of: Journal of the Electrochemical Society. Volume 162:Issue 3(2015)
• Page Start: F310
• Page End: F316
• Publication Date: 2015-01-06
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0751503jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Synchrotron based X-ray tomographic microscopy (XTM) is used for imaging and quantifying the redistribution of phosphoric acid (PA) in high temperature polymer electrolyte fuel cells (HT-PEFC) in-operando . The main focus of this work is the redistribution of phosphoric acid under dynamic load conditions. Therefore, two different load cycling protocols were applied and the transient redistribution within the fuel cell components was imaged. XTM, for the first time, revealed that the examined PBI based membrane system exhibits extensive electrolyte migration from cathode to anode under high current density operation. PA flooding of anode gas diffusion layer (GDL) and flow field channels occurred. Implications for technical applications and fuel cell degradation are discussed. Quantification of the migrated electrolyte is made by correlating in-operando grayscale values to ex-situ reference samples.