The era of "green hydrogen," which produces hydrogen without emitting carbon dioxide, has moved a step closer. A domestic research team has developed an ultrafast manufacturing technology that can complete the core equipment, solid oxide electrolysis cells (SOEC), in just 10 minutes. The same process used to take more than six hours.
Lee Kang-taek's team at Korea Advanced Institute of Science and Technology (KAIST) said on the 28th that it succeeded in drastically shortening the sintering process needed to make electrolysis cells and lowering the temperature from 1,400 degrees to 1,200 degrees.
Sintering is the process of firing ceramic powder at high temperatures so that the particles bond firmly to each other. This step must proceed well to prevent hydrogen and oxygen from mixing inside the cell (to avoid explosion risk), to allow current to flow smoothly, and to extend the cell's lifespan. The problem was that this process required many hours of high-temperature heating and cooling.
The team introduced "microwave volumetric heating." Instead of heating the cell from the outside, it heats it from the inside simultaneously, delivering heat much faster and more uniformly than existing methods. As a result, the entire sintering process was completed in about 70 minutes, more than 30 times faster than conventional processes.
In conventional methods, ceria (CeO₂) and zirconia (ZrO₂), the key materials of the cell, mixed with each other at excessively high temperatures, degrading quality. The new technology controls the two materials to bond firmly only at appropriate temperatures, successfully forming a dense electrolyte layer.
The cell produced this way generated 23.7 mL of hydrogen per minute at 750 degrees and operated stably for more than 250 hours. A three-dimensional Digital Twin (virtual simulation) analysis also confirmed that ultrafast heating tunes the microstructure of the material to improve hydrogen production efficiency.
Lee said, "This technology is a new manufacturing paradigm that can make high-performance electrolysis cells much faster and more efficiently," adding, "It can save a great deal of energy and time, giving it strong potential for commercialization."
The findings were published on the 2nd in the international journal Advanced Materials and were selected as a cover paper.
References
Advanced Materials (2025), DOI: https://doi.org/10.1002/adma.202500183