Ceramic fuel cells offer the world’s best performance at intermediate temperatures

Professor Joon Hyung Shim’s team publishes their paper in Advanced Energy Materials

▲ Joon Hyung Shim (principal investigator and co-corresponding author, Korea University), Ji-Won Son (principal investigator and co-corresponding author, KIST), and Kiho Bae (first author, Korea University)

A joint research team led by Professor Joon Hyung Shim of the School of Mechanical Engineering at Korea University and Dr. Ji-Won Son of KIST succeeded in developing ceramic fuel cells that offer the world’s best performance at intermediate temperatures (300–600°C).

With Professor Kiho Bae of the School of Mechanical Engineering at Korea University as the first author, the team published its results in the latest issue of Advanced Energy Materials (IF: 21.875, top 1.712% in the JCR), a leading journal in energy research.

* Title of Publication: High-performance Protonic Ceramic Fuel Cells with 1 μm Thick Y:Ba(Ce,Zr)O3 Electrolytes

The study was supported by the Korea Institute of Energy Technology Evaluation and Planning (President Chun-Taek Rim), and the Global Frontier R&D Program of the Ministry of Science and ICT (Minister You Young Min).

Fuel cells can be classified according to the operating temperature for their electrolytes: low temperature (below 200°C) and high temperature (above 600°C). While low-temperature fuel cells require the use of expensive platinum catalysts, high-temperature fuel cells can be fabricated using more affordable ceramic materials. However, the latter type of fuel cell tends to be less durable in the long term due to the high operating temperatures. Ceramic fuel cells that operate in the intermediate temperature range of 300 to 600°C have thus come under the global spotlight as a possible solution to this issue.

▲ Joon Hyung Shim (principal investigator and co-corresponding author, Korea University)

▲ Kiho Bae (first author, Korea University), 

Joon Hyung Shim (principal investigator and co-corresponding author, Korea University)

Protonic ceramic fuel cells (PCFCs) are fuel cells made of ceramic materials that generate energy from the conduction of hydrogen ions. Protonic ceramics are recognized as a next-generation material for fuel cells as they exhibit a 100-fold increase in conductivity compared to existing ceramic electrolytes at intermediate temperatures. Despite this advantage, they are difficult to fabricate as thin films and do not bind well to other ceramic materials.

The KU-KIST joint research team developed a multi-scale PCFC structure capable of fabricating thin-film electrolytes, and reported a two-fold improvement in performance compared to existing PCFCs. The proposed thin-film electrolytes maximized PCFC performance by significantly reducing the high resistance at the grain boundary, which has been the most significant limitation of protonic ceramics.

Of particular interest in this study was that the team succeeded in developing high-performance PCFCs based on Y:Ba(Ce,Zr)O3, which has been commonly used in protonic ceramic research. In the future, the multi-layer PCFC structure can easily be enhanced with the use of new materials that offer better performance.

Professor Shim said, “By developing PCFC stacks capable of stable operation at intermediate temperatures, we can expand the scope of ceramic fuel cells from power stations to general households and use them as portable power sources.”

[Figure Description] Schematic diagram of the microstructure of the multi-scale thin-film PCFC (left) and SEM image (right)

[Figure Description] Comparison of peak power densities in this study with those of reference PCFCs according to temperature