Methods for investigating degradation phenomena in membrane electrode assemblies (MEA)

Full text: The aim of this paper is to present the methods used for the investigation of the degradation phenomena that appears in the membrane electrode assemblies (MEA) of the Proton Exchange Membrane Fuel Cells (PEMFC). The proton exchange membrane fuel cell transforms the chemical energy which is produced during the electrochemical reaction of hydrogen and oxygen to electrical energy. One of the most important aspects in the commercialization of PEMFC is represented by its durability in time. In this respect, it is very important to understand the degradation phenomena, its causes and mechanisms. There are three types of degradation: thermal degradation, due to the low or high operating temperature; mechanical degradation due to manufacturing defects or wrong assembly of MEA; non-uniform compression; chemical degradation which includes the radical attacks, growth, migration and contamination of platinum particles; corrosion of the carbon support.The most common methods used for investigation of degradation phenomena in MEA are: Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), Energy Dispersive X-ray Analysis (EDX). (authors)