| Title |
Electrodeposition Process Conditions and Microstructure for Uniform Co Coatings on SOFC Interconnects |
| Authors |
이기영(Ki-young Lee); 최재훈(Jae-hun Choi); 신한균(Han-kyun Shin); 이효종(Hyo-jong Lee); 박현(Hyun Park); 김정한(Jung Han Kim) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.7.494 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
SOFC; interconnect; Co coating; electrodeposition; thickness uniformity; microstructure |
| Abstract |
Interconnects in solid oxide fuel cells (SOFCs) serve as electrical pathways between individual cells while also separating the fuel and air streams in each cell. For SOFCs operating at low temperatures (600 ~ 800 ℃), ferritic stainless steel with high Cr content is commonly used as the interconnect material. However, Cr evaporation during operation poses a significant durability issue for SOFCs. To prevent Cr evaporation, efforts have been made to apply a proper thin metallic coating on the interconnect surface. In this study, we investigated Co electrodeposition technologies to improve the thickness uniformity of Co coatings deposited on planar-type ferric stainless-steel interconnects with a trenched air-fuel pattern. First, we developed a strike process to ensure strong adhesion between the Co coating and the stainless-steel substrate, which was then combined with the main deposition step. Using the two-step electrodeposition process, several Co thin films were deposited on the patterned substrate depending on the current density applied during deposition, and their local thicknesses along the patterned surface were compared. The microstructure and texture of the location where the thickness was measured were identified using the electron backscatter diffraction (EBSD) technique and the electrochemical behaviors at different current densities was simulated using finite element analysis software. The results indicate that the uniformity of Co coating thickness on the patterned substrate is significantly influenced by solution flow and ion diffusion behaviors, which vary across the patterned surface. These factors affect the Co ion concentration near the substrate or deposit surface, ultimately influencing the microstructural evolution of the Co coating.(Received 29 November, 2024; Accepted 3 June, 2025) |