Keimyung University team develops defect-control technology for hydrogen fuel cell materials using shockwave flow

Keimyung University announced Friday that a joint research team led by Kim Ik-hyeon, a professor of mechanical engineering, and Kim Jun-seok, a professor of advanced materials engineering, has developed a technology to control defect structures in key materials for next-generation hydrogen fuel cells using shockwave flow.

The research systematically identified changes in oxygen vacancies and crystal lattice distortion inside proton-conducting ceramics through shockwave flow, demonstrating the potential of non-equilibrium defect engineering.

The findings were published in the international journal Ceramics International (top 7.4% in JCR, Q1) under the title "Shockwave-driven oxygen defect evolution and lattice distortion in BCZYYb proton-conducting ceramics."

Proton-conducting ceramics serve as the core electrolyte material in next-generation protonic ceramic fuel cells (PCFCs).

Oxygen vacancies inside the material play a critical role in forming pathways for hydrogen ion transport. Conventional methods — such as doping with new elements or high-temperature heat treatment — have faced limitations due to complex process conditions and compositional changes.

In response, the research team used repeated shockwave flow to create instantaneous non-equilibrium conditions inside the material, then systematically analyzed the resulting structural changes through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area analysis and particle size analysis (PSA).

The team confirmed that oxygen vacancies and Ce3+ concentrations increased with repeated shockwave cycles before stabilizing beyond a certain threshold — a non-equilibrium phenomenon in which defect formation and structural stabilization occur simultaneously under shockwave exposure.

"This research demonstrates that shockwaves can be used not merely as a physical impact but as a process technology to control the defect structure of functional materials," Kim Jun-seok said. "We expect it to contribute to improving the performance of various energy materials, including hydrogen fuel cells, and to advancing next-generation materials design."

Kim Ik-hyeon said the team plans to extend shockwave-based materials processing to a wider range of functional materials and develop it into a new materials design platform.

Kim Jun-seok served as lead author on the study, with researcher Lee Jae-ik, Dr. Sivaprakash Paramasivam and professor Do Dal-hyeon participating as co-authors. Kim Ik-hyeon served as principal investigator. The research was supported by the National Research Foundation of Korea's Excellent Young Researcher program and Keimyung University's Bisa research fund.