Metasurface-engineered anode for solid oxide electrolysis cells.

Kurushina, Victoria; Hossain, Mamdud; Prathuru, Anil; Soman, Ajith; Horri, Bahman Amini; Cai, Qiong; Faisal, Nadimul

Abstract

Solid oxide electrolysis (SOE) is a high temperature technology for the onsite production of oxygen and energy production in the form of hydrogen. Its' in-situ resource utilization potential is confirmed in the work by Hoffman et al. (2023) for oxygen production from carbon dioxide in the Martian conditions for a stack of ten cells. SOE at present is adapted for several feedstock materials, with steam electrolysers dominating in terrestrial applications. For either feedstock material, a combined use of the heat and electrical energy results in the superior electrical efficiency, compared to low-temperature electrolysis technologies. SOE allows a direct utilization of heat from nuclear, solar and alternative energy sources, including waste heat from high-temperature processes. Its high efficiency, scalability and use of solid materials make SOE a promising technology for solving Earth-bound energy production challenges, sustainable space exploration and long-term planetary colonization. At present, directions of development for solid oxide electrolysis cells (SOECs) include improving efficiency, durability and scalability for long-term operation in both terrestrial and space applications. Using metasurfaces for a single or multiple thin functional layers of the cell is one of the ways to enhance the electrical performance, as discussed in Jang et al. (2022) from the structural perspective. A metasurface represents an engineered geometrical pattern in the material layer at a millimetre to microscale, which translates into an additional electrochemically active surface area for a cathode or anode, that is in a direct contact with a fluid flow and changes its dynamics. Introducing metasurface patterns in electrochemically active layers opens a new space for design improvements, limited by the manufacturing capability. The current presentation provides a summary of complete simulation results for an anode with metasurfaces, varying in terms of types and sizes of elements. The study considers 1/16 sector model of a tubular solid oxide high-temperature steam electrolysis cell with a thick metal support layer, operating at 800 oC. Parallel flow conditions are considered, where the high temperature steam is supplied into the internal fluid channel, and the external flow of air is in a direct contact with the metasurface-patterned anode. Computation fluid dynamics (CFD) approach with the resolved electrolyte model in ANSYS Fluent is used to evaluate the current density characteristics for the selected SOEC design. The computational model is verified and validated with solid oxide fuel cell results. The study, first, evaluates the basic cell design and the geometrical pattern of rectangular elements, varying in height, length, width and distance from each other. The main outcome from this part of the work is the most beneficial combination of sizes for the rectangular pattern, reaching the increase in the electrical performance by 6.7%, compared to the base case at 1.5V of applied voltage, given 1.1V open circuit voltage. The second part of the conducted research is focused on the type of the geometrical element, considering rectangular, line and net-structured elements. From this part of the research, the net-structured metasurface is found to increase the current density by 8.5%, being the most efficient considered design, according to Kurushina et al. (2024). A net-structured surface is composed of both parallel and cross-flow line-elements. The observed electrical efficiency is linked to the patterns of air circulation along the engineered anode surface. Overall, the current study contributes to the field of knowledge by recommending net-structured metasurface-engineered anodes for practical applications, based on the performed simulations, optimization and comparison of design options. Future work in this direction could consider optimizing sizes of a net-structured metasurface for SOE.

Citation

KURUSHINA, V., HOSSAIN, M., PRATHURU, A., SOMAN, A., HORRI, B.A., CAI, Q. and FAISAL, N. 2025. Metasurface-engineered anode for solid oxide electrolysis cells. To be published in Proceedings of the 36th Thermal and fluid analysis workshop 2025 (TFAWS 2025), 4-7 August 2025, San Jose, CA, USA. Washington: NASA [online], In Press. To be made available from: https://tfaws.nasa.gov/about/archives/

• Presentation Conference Type: Presentation / Talk
• Conference Name: 36th Thermal and fluid analysis workshop 2025 (TFAWS 2025)
• Start Date: Aug 4, 2025
• End Date: Aug 7, 2025
• Acceptance Date: Jun 13, 2025
• Deposit Date: Aug 14, 2025
• Publisher: National Aeronautics and Space Administration (NASA)
• Peer Reviewed: Peer Reviewed
• Keywords: Solid oxide electrolysis (SOE); High temperature technology; Oxygen production; Energy production; Hydrogen
• Public URL: https://rgu-repository.worktribe.com/output/2973826
• Publisher URL: https://tfaws.app/proceedings