Decoupling Electronic–Ionic Transport and Catalysis Enables High-Performance, Chemically Stable Sr-Free Air Electrodes for High-Temperature Solid Oxide Cells

Decoupling Electronic–Ionic Transport and Catalysis Enables High-Performance, Chemically Stable Sr-Free Air Electrodes for High-Temperature Solid Oxide Cells

Professor Jong-Sup Hong’s research team, including Ph.D. candidate Ji-Eun Won and alumnus Dr. Woo-Seok Lee, developed a Sr-free air-electrode design technology for high-performance, highly durable solid oxide cells (SOCs) through collaborative research with the Korea Institute of Science and Technology (KIST) and Hyundai Motor Company. The research team focused on the problem of strontium (Sr), which is widely used in conventional high-performance air electrodes, segregating to surfaces and interfaces during high-temperature operation and reacting with elements such as chromium (Cr), thereby degrading electrode performance and chemical stability. To address this issue, the team moved beyond the conventional approach of integrating electronic conductivity, oxygen-ion conductivity, and surface catalytic activity into a single material. Instead, they proposed a composite electrode architecture that combines materials responsible for distinct functions, enabling the independent optimization of electronic conductivity, oxygen-ion conductivity, and the surface reaction activity of nanocatalysts. The developed Sr-free electrode maintained stable operating characteristics with virtually no performance degradation over 200 hours under electrolysis conditions. This study demonstrates that separating and optimizing the key functions of the air electrode by material can achieve high electrochemical performance while mitigating the persistent degradation associated with Sr. The technology is expected to contribute to improving the long-term reliability and commercialization of solid oxide electrolysis cells (SOECs) for high-efficiency hydrogen production. The findings were published in Advanced Science, a prestigious international journal in the field of materials science (2025 Impact Factor: 14.1; top 9.4% in the JCR Thermodynamics category).

The link: https://doi.org/10.1002/advs.77023