Modeling and coating development of metal based flow plates for PEM fuel cells in electric vehicles

The aim of this thesis is to increase the power obtained from hydrogen fuel cells, which are expected to become widespread in the future as clean and environmentally friendly energy generators. For this purpose, the flow plates, which are vital components of the cell, have been worked on both in terms of design and material structure. Three different approaches have been taken to redesign these flow plates in the cell. These redesigned flow plates were modeled in CATIA V5 and simulated in ANSYS. Current density values, pressure, temperature, hydrogen, oxygen, water, and reaction heat source distributions of the fuel cells were obtained and compared. As a result of this stage, the model providing the highest net power output compared to the triple serpentine model was determined to be produced and experimentally tested. In the second stage of the study, a metallic flow plate was coated with a multi-material structure using the EPD (Electrophoretic Deposition) method, aiming to improve the surface contact resistance and corrosion current density of the flow plate material. With the EPD method, a coating consisting of Ni/Cr/Ta/graphene composition was applied onto aluminum, nickel, and 316L stainless steel samples. After the coating process, critical parameters for the flow plates in fuel cells, namely interfacial contact resistance (ICR) and corrosion current density (Icor), were measured. Additionally, surface characterizations of the coatings were carried out through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses. Finally, the flow plate model providing the highest net power and a flow plate with an appropriate material structure were produced and experimentally tested in a single-cell fuel cell structure. Ultimately, an original flow plate model specific to the literature is presented.