Novel Fabrication Approach by Reversely Coating a Nafion Ionomer on Gas Diffusion Electrodes for High-Performance Membrane Electrode Assemblies

Abstract

For optimal performance of proton-exchange membrane fuel cells (PEMFCs), it is necessary to optimize the interfacial contact between the proton-exchange membrane (PEM) and the catalyst layer (CL) in membrane electrode assemblies (MEAs). We have proposed a novel fabrication approach for the MEA of PEMFCs, whereby the perfluorosulfonic acid (PFSA) dispersion is coated on a substrate to form a wet film, and then a gas diffusion electrode (GDE) is placed on the wet PFSA film. After drying, separation from the substrate yields a PFSA membrane-coated electrode. In the traditional preparation method for membrane-coated electrodes, liquid PFSA ionomer suspension can easily penetrate into cracks and voids in the CL, resulting in its overfilling. This can hinder gas transmission and lead to the serious detriment of the electrochemical properties of the fuel cell. In our MEA method, the GDE floats on the wet PFSA film, avoiding excessive penetration of the liquid PFSA dispersion suspension into the CL as a result of gravity. That not only achieves excellent interfacial contact between the PEM and the CL but also prevents overfilling with the PFSA ionomer. Applying this novel MEA method, we have achieved a high peak power density of 2636 mW cm–2 [O2, 0.1 MPa, and 100% relative humidity (RH)], a reduced performance loss at a low RH, and the fabrication of extremely thin PEMs (down to 10–12 μm).

Review on Chitosan and Two-Dimensional MoS2-Based Proton Exchange Membrane for Fuel Cell Application: Advances and Perspectives

“…The PEM is the essential part of the fuel cell, allowing passage for proton conduction and blocking the flow of electrons and fuel. , High methanol crossover and decreased proton conduction ability at high emperature limit the use of Nafion membranes . Therefore, developing a new low-cost polymer electrolyte membrane (PEM) with desired characteristics is becoming an imperative goal for the research community …”

“…The need for green and clean energy has sparked a lot of research interest in finding new ways to reduce problems, including the energy crisis, air pollution, and global warming. Due to its extreme environmental friendliness and high economic viability, hydrogen energy is one of the most influential and promising sustainable energy sources. , …”

“…Due to its extreme environmental friendliness and high economic viability, hydrogen energy is one of the most influential and promising sustainable energy sources. 2,3 Fuel cell technologies are among the most promising energy conversion techniques and the best prospects to replace petroleum energy, owing to their efficient and environmentally friendly nature. 4 PEMFCs, or proton-exchange membrane fuel cells, are viewed as a potential technology for producing power effectively in the 21st century.…”

“…5,6 High methanol crossover and decreased proton conduction ability at high emperature limit the use of Nafion membranes. 3 Therefore, developing a new low-cost polymer electrolyte membrane (PEM) with desired characteristics is becoming an imperative goal for the research community. 6 Chitosan (CS) has been broadly explored as a solid polymer electrolyte in different types of fuel cells such as DMFC and PEFC.…”

Preparation of an Integrated Membrane Electrode Assembly for Proton Exchange Membrane Fuel Cells Using a Novel Wet-Bonding Strategy

“…22−25 The PEM was directly deposited on the surface of the CL, effectively reducing the PEM/CL interfacial resistance and enhancing the mass transport in the MEA. 23,26,27 Ding et al prepared the MEAs by an extrusion slot coating of the electrolyte dispersion on the GDE surface. They found the flatness of the final membrane depended on the CL surface quality and the ionomer dispersion would fill any cracks during the coating process, which altered the pore structure and charge transfer balance of CLs.…”