Estimation of microscale redox tolerance for Ni-based solid oxide fuel cell anodes via three-dimensional finite element modeling

• Published in: International journal of hydrogen energy Vol. 48; no. 3; pp. 1060 - 1074
• Main Authors: Altan, Tolga, Celik, Selahattin, Toros, Serkan, Korkmaz, Habip Gokay, Timurkutluk, Bora
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 08.01.2023
• Subjects: Element deletion; Micro-modeling; Nickel anode; Redox; Solid oxide fuel cell; Synthetic microstructure generation; Redox; Nickel anode; Element deletion; Micro-modeling; Solid oxide fuel cell; Synthetic microstructure generation
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.10.019

Reduction-oxidation (redox) cycles of Ni-based anodes in solid oxide fuel cells (SOFCs) directly affect the cell performance due to breaking anode three/triple phase boundary (TPB) networks at microscale. Furthermore, these microcracks accumulate with the number of redox cycles leading to mechanical damage in the cell as a result of continuous volumetric changes during the inevitable cyclic reduction and oxidation of the nickel oxide and nickel, threatening the service life of SOFC systems. Therefore, the redox process needs to be investigated as a phenomenon at microscale to understand and minimize its effects. In this regard, we suggest a microscale approach for the redox process of Ni-based SOFC anodes in this study. For this purpose, SOFC anode microstructures with different compositions and porosities are synthetically generated by Dream.3D software and mechanical damages due to the redox cycle are investigated via element deletion through LS-DYNA for the first time in the literature. The anodes are characterized by computing the redox tolerance based on the resultant damage and the anode composition showing the highest redox tolerance is determined among the cases considered. •Microscale redox tolerance of Ni-based solid oxide fuel cell anodes is studied.•Synthetic anode microstructures with various properties are generated.•Effects of anode composition and porosity on the redox tolerance are investigated.•A model, based on the deletion of mechanically damaged elements, is employed.•Redox tolerance enhances with decreasing the Ni content or increasing the porosity.