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Electron microscopy to study membrane electrode assembly (MEA) materials and structure degradation

Advances in Electrocatalysis, Materials, Diagnostics and Durability

Performance degradation

Low-temperature fuel cells

  1. M. Chatenet1,
  2. L. Guetaz2,
  3. F. Maillard1

Published Online: 15 DEC 2010

DOI: 10.1002/9780470974001.f500056

Handbook of Fuel Cells

Handbook of Fuel Cells

How to Cite

Chatenet, M., Guetaz, L. and Maillard, F. 2010. Electron microscopy to study membrane electrode assembly (MEA) materials and structure degradation. Handbook of Fuel Cells. .

Author Information

  1. 1

    Laboratoire d'Electrochimie et de Physicochimie des Matériaux et des Interfaces (LEPMI), Saint Martin d'Hères, France

  2. 2

    CEA, LITEN, Grenoble Electron Microscopy-Minatec, Grenoble, France

Publication History

  1. Published Online: 15 DEC 2010

Abstract

The mass production of proton exchange membrane fuel cell (PEMFC) for stationary or mobile applications requires long-term durability and minimization of the voltage loss observed upon operation. The extent of PEMFC performance degradation depends on the type of materials composing the membrane electrode assembly (MEA), their manufacturing technique, their structure, and the operating conditions of the cell. Recently, electron microscopy (EM) has become a technique of choice to achieve a better understanding of the physical/chemical origin of the MEA degradation as a function of operation time. Unlike most other physical, chemical, and electrochemical in situ or ex situ techniques (global techniques), EM enables the identification of local changes to the various components of the MEA. For example, defect formation at the micrometer scale in the proton exchange membrane (PEM) and the active layer (observed by scanning electron microscopy), change of porosity and redistribution of the electrocatalyst at the nanometer scale (observed by field-emission gun scanning electron microscopy (FEG-SEM) and transmission electron microscopy (TEM)), or structure/composition degradation of electrocatalyst nanoparticles at the atomic scale (observed by high-resolution transmission electron microscopy (HRTEM)) can be derived from EM. A combination of the conclusions derived from local EM observations with those derived from other global characterization techniques yields the determination of MEA degradation mechanisms and provides some important routes to improve the PEM fuel cell performance and durability.

Keywords:

  • membrane electrode assembly (MEA);
  • active layer (AL);
  • proton exchange membrane (PEM);
  • mid- and long-term durability;
  • defect formation;
  • structure degradation;
  • scanning electron microscopy (SEM);
  • transmission electron microscopy (TEM);
  • X-ray energy-dispersive spectroscopy (XEDS)