Synthesis, Processing and Properties of Calcium- and Nickel-Doped Yttrium Chromates(III) Y0.8Ca0.2Cr1−xNixO3 (x = 0-0.3) and Studies on Their Potential Application as Coatings for SOFC Interconnects

• Published in: Journal of materials engineering and performance 2018-07, Vol.27 (7), p.3276-3289
• Main Authors: Stygar, M., Tejchman, W., Dąbrowa, J., Kruk, A., Brylewski, T.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-018-3422-7

In the present study, a calcium- and nickel-doped yttrium chromates (YCCN)-based, conductive–protective layers for metallic interconnects used in the intermediate-temperature solid oxide fuel cells (IT-SOFCs) were investigated. Synthesis of Y 0.8 Ca 0.2 Cr 1− x Ni x O 3 ( x  = 0; 0.15 and 0.3) powders was performed using a wet chemistry method with two different complexing agents: ethylenediaminetetraacetic acid and glycine. Based on the result of thermal analysis of obtained precursors, optimal conditions of the calcination process were determined. Powders were then milled, compacted and sintered at different temperatures using free sintering method, into series of dense, polycrystalline sinters. The use of glycine precursor allowed obtaining a single-phase material in all cases. Based on the electrical and sintering properties, the Y 0.8 Ca 0.2 Cr 0.85 Ni 0.15 O 3 material was selected for further studies. It was deposited using cost-effective screen-printing method on the Crofer 22APU ferritic stainless steel. To investigate properties and suitability of the resulting layer/steel system for IT-SOFCs applications, the high-temperature, dual-atmosphere studies were carried out for the first time for ceramic/metallic system, in conditions as close as possible to actual working conditions of the fuel cell. The layer exhibited high stability and good protective properties. The area-specific resistance of the studied ceramic layer/metallic substrate composite was determined, with the obtained value of 0.0366 Ω cm 2 being within the arbitrary limit set for these materials (0.1 Ω cm 2 ). The results show that the investigated materials are suitable for the projected application.