Analysis of MEA (Membrane Electrode Assembly)

User Benefits

�- It is possible to analyze the performance deterioration behavior of fuel cells and other industrial products in which MEA (Membrane Electrode Assembly) is used. �- EPMA can also be utilized in research and development and quality improvement for cost reduction, long life, and enhanced stability of MEA.

Introduction

Electrochemical devices in which electrode catalyst layers are bonded on a solid polymer electrolyte membrane, which is a hydrogen ion conductor, are called membrane electrode assemblies (MEA), and are used in diverse applications including fuel cells, technologies for water electrolysis hydrogen production technologies, and dehumidifying cells. The solid polymer electrolyte membrane consists mainly of tetrafluoroethylene (CF₂-CF₂) as the backbone chain and a side chain with a terminal sulfonic acid group (-SO₃H). Nafion^TM is a representatively commercial product. The sulfonic acid group is hydrophilic and is filled with water molecules when humidified. When hydrogen ions are generated here, they bond with the water molecules, forming oxonium (hydronium) ions (H₃O⁺), and migrate by jumping successively by way of adjacent water molecules. The electrode catalyst layers on the two sides of the solid polymer electrolyte membrane are mainly made of Pt and have the function of activating the oxidation-reduction reaction. In MEA, cost reduction, long life, and high stability have become important issues. For example, it is known that the chemical stability of the electrolyte membranes is reduced depending on temperature characteristics, and performance is deteriorated by agglomeration of the catalyst. An understanding of the layer structure, the distribution of each element, and the deterioration behavior of the MEA is required in order to suppress these problems. This article introduces an example of an analysis by a comparative evaluation of a new MEA before use and a product with deteriorated performance using a Shimadzu EPMA-8050G EPMA^TM electron probe microanalyzer.

May 27, 2021 GMT