Electrode degradation mechanisms studies by current distribution measurements
Advances in Electrocatalysis, Materials, Diagnostics and Durability
Low-temperature fuel cells
Published Online: 15 DEC 2010
Copyright © John Wiley & Sons, Ltd. All rights reserved.
Handbook of Fuel Cells
How to Cite
Carter, R. N., Gu, W., Brady, B., Yu, P. T., Subramanian, K. and Gasteiger, H. A. 2010. Electrode degradation mechanisms studies by current distribution measurements. Handbook of Fuel Cells. .
- Published Online: 15 DEC 2010
A technique is described for determining the source and degree of electrodes degradation in membrane electrode assemblies (MEAs) from proton exchange membrane fuel cells. This technique is nondestructive and provides spatial resolution across the MEA's active area. The degradation modes that are considered are the oxygen reduction activity loss through either electrochemically active area or mass activity loss, increased gas transport resistance from corrosion of the catalyst's carbon support, and the increased protonic transport loss through chemical degradation of the electrode layer's ion-conducting polymer. A current distribution tool is used with cyclic voltammetry and polarization curves to isolate each of the primary sources of voltage degradation. Results of new MEAs are presented first to demonstrate the approximate resolution of the test method. Then results are presented for MEAs that were aged in a model test to cause carbon corrosion in the cathode layer via localized anode starvation. These include follow-up materials characterization, where it is shown that the results of this electrochemical diagnostic correlate well with postmortem materials characterization. Finally, results are shown for a part aged in a model start-up/shutdown aging test and compared with modeling results to explain the spatial characteristics of the observed degradation.
- current distribution;
- electrode diagnostic;
- mass activity;
- gas transport;
- proton transport;
- carbon corrosion