Researchers improve solid oxide fuel cell threefold

A research team has successfully developed a catalyst coating technology that significantly improves the performance of solid oxide fuel cells (SOFCs) in just four minutes.

Dr. Yoonseok Choi from the Hydrogen Convergence Materials Laboratory at the Korea Institute of Energy Research (KIER), in collaboration with Professor WooChul Jung from the Department of Materials Science and Engineering at KAIST and Professor Beom-Kyung Park from the Department of Materials Science and Engineering at Pusan National University, led the research.

Their findings were published in Advanced Materials.

Fuel cells are gaining attention as highly efficient and clean energy devices driving the hydrogen economy. Among them, solid oxide fuel cells (SOFCs), which have the highest power generation efficiency, can use various fuels such as hydrogen, biogas, and natural gas. They also allow for combined heat and power generation by utilizing the heat generated during the process, making them a subject of active research and development.

The performance of solid oxide fuel cells (SOFCs) is largely determined by the kinetics of oxygen reduction reaction (ORR) occurring at the air electrode (cathode). The reaction rate at the air electrode is slower than that of the fuel electrode (anode), thus limiting the overall reaction rate.

To overcome this sluggish kinetics, researchers are developing new air electrode materials with high ORR activity. However, these new materials generally still lack chemical stability, requiring ongoing research.

Instead, the research team focused on enhancing the performance of the LSM-YSZ composite electrode, a material widely used in industry due to its excellent stability. As a result, they developed a coating process for applying nanoscale praseodymium oxide (PrO_x) catalysts on the surface of the composite electrode, which actively promotes the oxygen reduction reaction. By applying this coating process, they significantly improved the performance of solid oxide fuel cells.

The research team introduced an electrochemical deposition method that operates at room temperature and atmospheric pressure, requiring no complex equipment or processes. By immersing the composite electrode in a solution containing praseodymium (Pr) ions and applying an electric current, hydroxide ions (OH^-) generated at the electrode surface react with praseodymium ions, forming a precipitate that uniformly coats the electrode.

This coating layer undergoes a drying process, transforming into an oxide that remains stable and effectively promotes the oxygen reduction reaction of the electrode in high-temperature environments. The entire coating process takes only four minutes.