Coatings Application and Corrosion Protection | |
ArticleName | Study of the evolution of surface morphology and elemental composition of coatings based on cobalt-manganese spinel of current collectors of solid oxide fuel cells in an oxidizing environment |
DOI | 10.17580/chm.2025.05.13 |
ArticleAuthor | A. V. Khramenkova, O. A. Finaeva, N. V. Demeneva, E. A. Yatsenko |
ArticleAuthorData | Platov South-Russian State Polytechnic University (NPI), Novocherkassk, Russia E. A. Yatsenko, Dr. Eng., Prof., Head of the Dept. of General Chemistry and Technology of Silicates, e-mail: e_yatsenko@mail.ru Institute of Solid State Physics of the Russian Academy of Sciences (ISSP RAS), Chernogolovka, Russia |
Abstract | The paper presents data on the performance of physical and chemical properties of Co-Mn spinel-based coatings during area-specific resistance measurements in a model solid oxide fuel cell. Synthesis of coatings was carried out using the method of non-stationary electrolysis. When comparing microphotographs of coatings before and after high-temperature oxidation, it can be seen that crystallisation of coatings and enlargement of their constituent fragments during oxidation occur. Thus according to the data of X-ray microanalysis it is established that in the process of oxidation there is an increase in concentration of chromium, manganese and iron that can be connected with diffusion of these elements from steel on a surface of a coating. From the XRD data, it can be seen that cobalt and manganese are distributed evenly over the coating surface, while chromium, which is part of the substrate, is concentrated in the cracks of the coating. From the X-ray diffraction data, it can be seen that the coating is in an X-ray amorphous state. It should be noted, however, that oxidation in air for 1000 h at 850 °C results in the coating becoming more crystallized. Thus, in addition to the Co-Mn spinel peak, Fe-Cr, Cr2O3 and Fe3O4 phases are observed. The study of the change in the weight gain of the coated and pure steel samples in the cyclic regime of heating-holding-cooling showed the following. Oxidation of uncoated Crofer 22 APU steel grows from the first hours of oxidation according to a parabolic law: the rate is determined by the thermodiffusion of chromium through the oxide growing on the steel surface to the surface. The coated samples show a decrease in mass in the first 10 hours, and then the weight gain also grows according to the parabolic law. The values of the calculated rate constants show the effectiveness of the developed coatings. |
keywords | Solid oxide fuel cells, interconnects, protective coatings, Co-Mn spinel, non-stationary electrolysis, high-temperature oxidation, parabolic rate constant of oxidation |
References | 1. Kalinina E. G., Pikalova E. Yu. New trends in the development of the electrophoretic deposition method in solid oxide fuel cell technology: theoretical approaches, experimental solutions and development prospects. Uspekhi khimii. 2019. Vol. 88. No. 12. pp. 1179–1219. |
Language of full-text | russian |
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