A Review of the Transition Region of Membrane Electrode Assembly of Proton Exchange Membrane Fuel Cells: Design, Degradation, and Mitigation

Abstract

As the core component of a proton exchange fuel cell (PEMFC), a membrane electrode assembly (MEA) consists of function region (active area), structure region, and transition region. Situated between the function and structure regions, the transition region influences the reliability and durability of the MEA. The degradation of the electrolyte membrane in this region can be induced by mechanical stress and chemical aggression. Therefore, prudent design, reliable and robust structure of the transition region can greatly help avoid early failure of MEAs. This review begins with the summarization of current structural concepts of MEAs, focusing on the transition region structures. It can be seen that aiming at better repeatability and robustness, partly or total integration of the materials in the transition region is becoming a development trend. Next the degradation problem at the transition region is introduced, which can be attributed to the hygro-thermal environment, free radical aggression, air pressure shock, and seal material decomposition. Finally, the mitigation approaches for the deterioration at this region are summarized, with a principle of avoiding the exposure of the membrane at the edge of the catalyst-coated membrane (CCM). Besides, durability test methods of the transition region are included in this review, among which temperature and humidity cycling are frequently used.

Structural Mechanics Analysis of Woven Web Reinforced Membranes in Proton Exchange Membrane Water Electrolysis

“…This area is critical as it represents a potential point of membrane failure. 6,9,11 The reason for that is, that a gap cannot be avoided and therefore the membrane has no support in this area. Additionally, the bipolar plates are neglected, and the compression is applied directly on the cell frame and the PTLs.…”

“…Here we focus on the mechanical impact on the membrane and the resulting deformations that can lead to cracks, pinholes, and membrane thinning. Such failures have been extensively investigated in the related PEM fuel cell community [3][4][5][6][7][8][9] and are recently shown to be an issue for PEM water electrolysis as well. 10,11 Decreasing the possibility of such damages can be achieved by reducing the mechanical stresses or by using thicker membranes.…”

Ionomer Membranes Produced from Hexaarylbenzene-Based Partially Fluorinated Poly(arylene ether) Blends for Proton Exchange Membrane Fuel Cells

“…PEMFCs have operate as an all-solid structure that makes them ideal for transport applications and also have a special polymer electrolyte membrane for conducting protons applications by enhancing electrolyte conductivity. The structure of the perfluorosulfonic acid (PFSA) membranes consists of a fluorinated backbone with a fluorocarbon side chain and possesses characteristics such as excellent ionic conductivity even in anhydrous conditions [13][14][15][16][17][18]. The most common commercial ionomers used for producing PEMs are PFSA-based ionomers, such as Nafion (Dupont) [1,[19][20][21][22], Aquivion ® (Solvay) [23][24][25][26], Flemion ™ (AGC Chemicals) [27][28][29], and 3M™ Ionomers (3M Company) [1,[30][31][32][33].…”

Electric Field-Assisted Filling of Sulfonated Polymers in ePTFE Backing Material for Fuel Cell

“…Hydrogen-based fuel cells are a promising source of energy because they produce energy merely through the fuel supplied to them by converting chemical energy into electric energy, with a theoretical conversion of 90%. A proton-exchange membrane fuel cell (PEMFC) consists of a polymer membrane for the electrolyte in the cell [ 2 , 3 ]. The solid polymer membrane effectively reduces the risk of electrolyte infiltration to other layers.…”