Professor Jaeyoung Lee's research team presents a new paradigm for carbon fuel cells
□ Professor Jaeyoung Lee of the School of Earth Sciences and Environmental Engineering and RISE at the Gwangju Institute of Science and Technology (GIST, President Seung Hyeon Moon) and Dr. Hansaem Jang have identified the cause of performance degradation in carbon fuel cells, which are attracting research interest as possible a next generation electrical energy production system.
∘ This achievement sets new standards for selecting and using fuel that can maximize the operational efficiency among the carbon-based materials, such as coal, waste coffee powder, and activated carbon, and it is possible to develop a new paradigm for securing stable energy.
□ Carbon fuel cells are thermodynamically superior power generation devices that are not hindered by Carnot cycle * and are attracting attention as next generation high temperature fuel cells because of various advantages, such as high efficiency, structural simplicity, and fuel flexibility. However, due to the abnormal performance degradation that is often observed, fuel cell operation is difficult.
* Carnot cycle: This is the thermodynamic energy circulation process that takes place in a heat engine, such as an internal combustion engine. In such an engine, the upper limit of the efficiency is determined, and there is a limitation in obtaining high efficiency.
∘ Generally, as the operating temperature rises, the fuel cell power production performance should improve. However, despite the increase in temperature, performance degradation is often observed, and overcoming this performance degradation is a problem that needs to be solved when operating carbon fuel cells.
□ The research team succeeded in identifying the cause of performance degradation, which was the biggest obstacle for carbon fuel cells. In addition, the correlation between carbon fuel properties * and carbon fuel cell performance was clarified with suggestions for further optimization of performance.
* Properties: Properties possessed by the substance. In this study, particular attention was paid to the specific surface area and the crystallinity of the carbon fuel among its various physical and chemical properties.
∘ The carbon fuel cell performance was determined by the degree of gasification * of the carbon fuel in the reactor. When the internal gasification was excessive, the performance decreased due to carbon deposition on the electrode surface. When the internal gasification was insufficient, the electrode itself deteriorated, and the performance decreased.
* Gasification: The process of making solid or liquid substances into gas.
∘ The degree of internal gasification was observed to increase when the carbon fuel had a high specific surface area or low crystallinity. Therefore, the team confirmed the conditions of carbon fuels to achieve optimum performance.
∘ The research team suggested a countermeasure for the two causes of deterioration of carbon fuel cell performance. When the performance is reduced due to carbon deposition, it is possible to optimize the performance by promoting ion movement by controlling the electric load. When the performance is reduced due to deterioration of the electrode, it is possible to optimize the performance by controlling the amount of oxygen supplied to the electrode.
□ Professor Jaeyoung Lee said, "This achievement will contribute to commercialization of power generation utilizing this technology to create suitable standards for carbon fuel cell operation. Based on this, we expect to provide a solution to performance degradation of this technology, thereby maximizing efficiency to produce stable energy."
