Standard Article

Cold-start durability of membrane-electrode assemblies

Advances in Electrocatalysis, Materials, Diagnostics and Durability

Performance degradation

Low-temperature fuel cells

  1. C. Y. Wang1,
  2. X. G. Yang1,2,
  3. Y. Tabuchi1,3,
  4. F. Kagami3

Published Online: 15 DEC 2010

DOI: 10.1002/9780470974001.f500057a

Handbook of Fuel Cells

Handbook of Fuel Cells

How to Cite

Wang, C. Y., Yang, X. G., Tabuchi, Y. and Kagami, F. 2010. Cold-start durability of membrane-electrode assemblies. Handbook of Fuel Cells. .

Author Information

  1. 1

    The Pennsylvania State University, University Park, PA, USA

  2. 2

    Ford Motor Company, Dearborn, MI, USA

  3. 3

    Nissan Motor Co. Ltd., Kanagawa, Japan

Publication History

  1. Published Online: 15 DEC 2010

Abstract

Durability of membrane-electrode assemblies (MEAs) cycled under cold-start conditions is reviewed. It is shown that MEAs cycled under 100 mA cm−2 from −30 °C show no degradation after 100 cycles, but exhibit mild degradation after 150 cycles under 300 mA cm−2 from −30 °C, and furthermore suffer severe degradation after 110 cycles under 500 mA cm−2 from −20 °C. Transmission electron microscopy (TEM) and X-ray diffraction using cross-sectional samples of the aged MEAs further revealed three primary degradation mechanisms: (i) interfacial delamination between the cathode catalyst layer (CL) and membrane, (ii) cathode CL pore collapse and densification upon melting of a fully ice-filled CL, and (iii) Pt particle coarsening and Pt dissolution in the perfluorosulfonic acid (PFSA) ionomer. The interfacial delamination and CL densification appear to be closely related to each other, and the key parameter to affect both is the ice volume fraction in the cathode CL after each cold-start step. Eliminating or minimizing these two degradation processes could improve the MEA cold-start durability by 280%. Mitigation strategies include improved gas purge prior to cold start, good MEA design, small start-up current density, and low cell thermal mass.

Keywords:

  • Polymer electrolyte fuel cells;
  • cold start;
  • membrane-electrode assembly durability