Research studying irreversible degradation of the MEA has focused on the perfluorinated sulfonic acid (PFSA) membrane, the ionomer in the CL, the Pt catalyst, and the carbon support [22,48,49]. Degradation is characterized by material aging and loss, and a change in morphology and microstructure of the components. Generally, the membrane can experience aging from thermal, mechanical, and chemical effects [48,50-52]. Thermal load accelerates decomposition of the molecular structure, of which the degradation induced by hot spots is typical.