Breaking through the Cracks: On the Mechanism of Phosphoric Acid Migration in High Temperature Polymer Electrolyte Fuel Cells

被引:30
作者
Halter, J. [1 ]
Marone, F. [2 ]
Schmidt, T. J. [1 ,3 ]
Buchi, F. N. [1 ]
机构
[1] Paul Scherrer Inst, Electrochem Lab, CH-5232 Villigen, Switzerland
[2] Paul Scherrer Inst, Swiss Light Source, CH-5232 Villigen, Switzerland
[3] Swiss Fed Inst Technol, Phys Chem Lab, CH-8093 Zurich, Switzerland
关键词
GAS-DIFFUSION LAYERS; ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY; X-RAY RADIOGRAPHY; POLYBENZIMIDAZOLE MEMBRANES; CATALYST LAYER; HT-PEFCS; PERFORMANCE; REDISTRIBUTION;
D O I
10.1149/2.0501814jes
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
In high temperature polymer electrolyte fuel cells, at high current densities, phosphoric acid (PA) migrates toward the anode and invades catalyst, microporous and gas diffusion layers (GDL). This work studies this PA redistribution using synchrotron based operando X-Ray tomographic microscopy (XTM) and electrochemical impedance spectroscopy (EIS) during a current cycling protocol. It is shown that under reformate conditions, during the first 2 minutes after a positive current step, the cell voltage increases due to better wetting of the anode catalyst layer (CL). From 2 to 20 minutes, the cell voltage drops due to increasing mass transport losses in the microporous layer (MPL) and the GDL. At the anode, cracks in MPL and CL, both with widths up to 150 mu m, are flooded within 2 minutes after a current density increase. Acid flooding is only observed for MPL cracks that overlap with CL cracks. The CL cracks therefore act as injection points for the flooding of the MPL cracks and the gas diffusion layer. No change in the PA content of any of the cathodic porous components was observed. (C) The Author(s) 2018. Published by ECS.
引用
收藏
页码:F1176 / F1183
页数:8
相关论文
共 36 条
[1]   A comprehensive review of PBI-based high temperature PEM fuel cells [J].
Araya, Samuel Simon ;
Zhou, Fan ;
Liso, Vincenzo ;
Sahlin, Simon Lennart ;
Vang, Jakob Rabjerg ;
Thomas, Sobi ;
Gao, Xin ;
Jeppesen, Christian ;
Kaer, Soren Knudsen .
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 2016, 41 (46) :21310-21344
[2]   Determination of Anion Transference Number and Phosphoric Acid Diffusion Coefficient in High Temperature Polymer Electrolyte Membranes [J].
Becker, Hans ;
Reimer, Uwe ;
Aili, David ;
Cleemann, Lars N. ;
Jensen, Jens Oluf ;
Lehnert, Werner ;
Li, Qingfeng .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2018, 165 (10) :F863-F869
[3]   Probing phosphoric acid redistribution and anion migration in polybenzimidazole membranes [J].
Becker, Hans ;
Cleemann, Lars Nilausen ;
Aili, David ;
Jensen, Jens Oluf ;
Li, Qingfeng .
ELECTROCHEMISTRY COMMUNICATIONS, 2017, 82 :21-24
[4]   Phosphoric Acid Invasion in High Temperature PEM Fuel Cell Gas Diffusion Layers [J].
Bevilacqua, N. ;
George, M. G. ;
Galbiati, S. ;
Bazylak, A. ;
Zeis, R. .
ELECTROCHIMICA ACTA, 2017, 257 :89-98
[5]   Evaluation of Neutron Imaging for Measuring Phosphoric Acid Distribution in High Temperature PEFCs [J].
Boillat, P. ;
Biesdorf, J. ;
Oberholzer, P. ;
Kaestner, A. ;
Schmidt, T. J. .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2014, 161 (03) :F192-F198
[6]   Role of the microporous layer in the redistribution of phosphoric acid in high temperature PEM fuel cell gas diffusion electrodes [J].
Chevalier, S. ;
Fazeli, M. ;
Mack, F. ;
Galbiati, S. ;
Manke, I. ;
Bazylak, A. ;
Zeis, R. .
ELECTROCHIMICA ACTA, 2016, 212 :187-194
[7]   Raman study of the polybenzimidazole-phosphoric acid interactions in membranes for fuel cells [J].
Conti, Fosca ;
Majerus, Anne ;
Di Noto, Vito ;
Korte, Carsten ;
Lehnert, Werner ;
Stolten, Detlef .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2012, 14 (28) :10022-10026
[8]   Operando X-ray Tomographic Microscopy Imaging of HT-PEFC: A Comparative Study of Phosphoric Acid Electrolyte Migration [J].
Eberhardt, S. H. ;
Marone, F. ;
Stampanoni, M. ;
Buchi, F. N. ;
Schmidt, T. J. .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2016, 163 (08) :F842-F847
[9]  
Eberhardt S. H., 2015, ECS Transactions, V69, P591, DOI 10.1149/06917.0591ecst
[10]   Dynamic Operation of HT-PEFC: In-Operando Imaging of Phosphoric Acid Profiles and (Re)distribution [J].
Eberhardt, S. H. ;
Toulec, M. ;
Marone, F. ;
Stampanoni, M. ;
Buechi, F. N. ;
Schmidt, T. J. .
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2015, 162 (03) :F310-F316