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Son, Young-Mok;Cho, Mann;Nah, Do-Baek;Kil, Sang-Cheol;Kim, Sang-Woo
- Journal of Energy Engineering
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- v.19 no.2
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- pp.73-80
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- 2010
A solid oxide fuel cells(SOFC) is a clean energy technology which directly converts chemical energy to electric energy. When the SOFC is used in cogeneration then the efficiency can reach higher than 80%. Also, it has flexibility in using various fuels like natural gases and bio gases, so it has an advantage over polymer electrolyte membrane fuel cells in terms of fuel selection. A typical cathode material of the SOFC in conjunction with yttria stabilized zirconia(YSZ) electrolyte is still Sr-doped $LaMnO_3$(LSM). Recently, application of mixed electronic and ionic conducting perovskites such as Sr-doped $LaCoO_3$(LSCo), $LaFeO_3$(LSF), and $LaFe_{0.8}Co_{0.2}O_3$(LSCF) has drawn much attention because these materials exhibit lower electrode impedance than LSM. However, chemical reaction occurs at the manufacturing temperature of the cathode when these materials directly contact with YSZ. In addition, thermal expansion coefficient(TEC) mismatch with YSZ is also a significant issue. It is important, therefore, to develop cathode materials with good chemical stability and matched TEC with the SOFC electrolyte, as well as with high electrochemical activity.
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Lee, Chang-Bo;Bae, Joong-Myeon
- Proceedings of the KSME Conference
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- 2007.05b
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- pp.2222-2227
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- 2007
Newly structured metal-supported solid oxide fuel cell was fabricated and characterized by impedance analysis and galvanodynamic experiment. Using a cermet adhesive, thin ceramic layer composed of anode(Ni/YSZ) and electrolyte(YSZ) was joined with STS430 metal support of which flow channel was fabricated. $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_3$ perovskite oxide was used as cathode material. Single cell performance was increased and saturated at operating time to 300hours at 800$^{\circ}C$ because of cathode sintering effect. The sintering effect was reinvestigated by half cell test and exchange current density was measured as 0.005A/$cm^2$. Maximum power density of the cell was 0.09W/$cm^2$ at 800$^{\circ}C$. Numerical analysis was carried out to classify main factors influencing the single cell performances. Compared to experimental IV curve, simulated curve based on experimental parameters such as exchange current density was in good agreement.
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Lee, Ki-Seong;Lee, Jai-Moon;Shim, Su-Man;Kim, Dong-Min
- Journal of Hydrogen and New Energy
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- v.22 no.3
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- pp.319-325
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- 2011
The electrical properties of sputtered GDC thin films on $Al_2O_3$ substrates was studied. The electrical properties of the films were measured to evaluate the ion conductivity of GDC thin films for co-planar SOFC electrolytes. The impedance of the GDC thin films on $Al_2O_3$ substrates was affected by the film thickness and the impedance of thin film exhibited higher value than thick films. Similarly, the conductivity of the thick film showed much higher value than thin films. It indicated that the film thickness is the main factor affecting the conductivity and impedance of the GDC electrolyte for the co-planar SOFC.
https://doi.org/10.7316/khnes.2011.22.3.319 인용 PDF KSCI

Jeong, Jihoon;Baek, Seung-Wook;Bae, Joongmyeon
- 한국신재생에너지학회:학술대회논문집
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- 2010.11a
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- pp.78.1-78.1
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- 2010
The metal-supported solid oxide fuel cell (SOFC) was studied. Hydrocarbon fueled operation is necessary to make SOFC system. Different operating characteristics for metal-supported SOFC are used than for conventional ones as hydrocarbon fueled operation. Metal-supported SOFC was successfully fabricated by a high temperature sinter-joining method and the cathode was in-situ sintered. Synthetic gas, which is compounded as the diesel reformate gas composition and low hydrocarbons was completely removed by the diesel reformer. Metal-supported SOFC with synthetic gas was operated and evaluated and its characteristics analyzed. Button cell and $5{\times}5cm^2$ single stack were mainly operated and analyzed. Long-term operation using diesel reformate shows degradation, and degradation analysis was completed in the view of metal oxidation. Solution to increase stability of long-term operation was tried in the way of materials and operating conditions. Finally, $5{\times}5cm^2$ metal-supported single stack using synthetic gas was operated for 1000 hours under the modified condition.
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