• Transactions on Electrical and Electronic Materials
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• v.12 no.1
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• pp.1-6
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• 2011

This paper summarized concept, manufacture and results of the micro-tubular solid oxide fuel cells (SOFCs). The cells were fabricated by co-sintering of extruded micro-tubular anode support and electrolyte coating layer, and then additional cathode coating. The cells showed quick voltage rising within 1 minute, and the electrochemical performances were closely related to the balance of fuel utilization and performance loss. And a thermal-fluid simulation model was also reported in combination with the electrochemical evaluation results on the GDC-based micro-tubular SOFCs.

• Ceramist
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• v.21 no.4
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• pp.366-377
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• 2018

Solid oxide fuel cells (SOFCs) are promising eco-friendly energy conversion system due to their high efficiency, low pollutant emission and fuel flexibility. High operating temperatures, however, leads to the crucial drawbacks such as incompatibility between the components and high thermal stress. Proton-conducting ceramic fuel cells (PCFCs) with proton-conducting oxide (PCO) materials are new types of fuel cells that can solve the problems of conventional SOFCs. Many studies have been proceeded to improve the performance of electrolytes and electrodes, and triple conductive oxides (TCOs) have attracted significant attention as high performance PCFC electrodes.

• Journal of Electrochemical Science and Technology
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• v.14 no.2
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• pp.145-151
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• 2023

Planer-type electrolyte substrates are often utilized for stack manufacturing of electrolyte-supported solid oxide fuel cells (ES-SOFCs) to fulfill necessary requirements such as a high mechanical strength and redox stability. This work did an electrochemical analysis of ES-SOFC with different NiO-YSZ anode thicknesses to find the optimal value for the high performance of the fuel cell. The cell resistivities were constant at anode thickness between 25-58 ㎛, but a thick anode (74 ㎛) caused a high electrode resistivity leading to a dramatic reduction in cell performance. A stability test was performed for 50 hours at 700℃, and the results showed a degradation rate of 0.3% per 1000 h by extrapolated fitting.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.391-394
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.573-574
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• 2012

• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.139-145
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• 2003

We studied oxidation behaviors of anti-oxidative Y-Cr oxide coated sol on ferritic steel for application of the Fe-Cr alloys as interconnectors of planar-type Solid Oxide Fuel Cells(SOFCs). In coated$YCrO_3$on the ferritic steel, the phases of $YCrO_3$,$Cr_2O_3$and $Mn_{1.5}Cr_{1.5}O_4$on the coated surface were detected, but iron base scales were not observed after oxidation at 80$0^{\circ}C$ for 40 h. The Mn-Cr oxide scales were grown with oxidation by diffusing components in the ferritic steel from inner. The Log(ASR/T) value that expresses electrical resistance of coated$YCrO_3$on the ferritic steel was -4.57~$-4.70{omega}cm^2K^{-1}$, lower in comparison with the one of the uncoated ferritic steel,$-3.99{omega}cm^2K^{-1}$. This indicates the applicability of Fe-l6Cr alloy as interconnector materials for SOFCs.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.132-139
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• 2020

Solid oxide fuel cells (SOFCs) are among one of the promising technologies for efficient and clean energy. SOFCs offer several advantages over other types of fuel cells under relatively high temperatures (600℃ to 800℃). However, the thermal behavior of SOFC stacks at high operating temperatures is a serious issue in SOFC development because it can be associated with detrimental thermal stresses on the life span of the stacks. The thermal behavior of SOFC stacks can be influenced by operating or material properties. Therefore, this work aims to investigate the effects of the thermal conductivity of each component (anode, cathode, and electrolyte) on the thermal behavior of samarium-doped ceria-based SOFCs at intermediate temperatures. Computational fluid dynamics is used to simulate SOFC operation at 600℃. The temperature distributions and gradients of a single cell at 0.7 V under different thermal conductivity values are analyzed and discussed to determine their relationship. Simulations reveal that the influence of thermal conductivity is more remarkable for the anode and electrolyte than for the cathode. Increasing the thermal conductivity of the anode by 50% results in a 23% drop in the maximum thermal gradients. The results for the electrolyte are subtle, with a ~67% reduction in thermal conductivity that only results in an 8% reduction in the maximum temperature gradient. The effect of thermal conductivity on temperature gradient is important because it can be used to predict thermal stress generation.

• Journal of the Korean Ceramic Society
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• v.42 no.10 s.281
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• pp.665-671
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• 2005

LSGM is known to show very serious interfacial reaction with other unit cell components, such as electrode, electrode functional or buffering layers. Especially, the formation of very resistive LaSr$Ga_{3}$$O_{7}$ phase at the interface of an anode and an electrolyte is the most problematic one in LSGM-based SOFCs. In this study, we investigated the interfacial reactions in LSGM-based SOFCs under different unit cell configurations. According to the microstructural analysis on the interfacial layer between an electrolyte and its neighboring component, serious interfacial reaction zone was observed. From the electrical and electrochemical characterization of the cell, we found such an interfacial reaction zone not only increased the internal ohmic resistance but also decreased the OCV(Open Cell Voltage) of the unit cell, and thus consequently deteriorated the unit cell performance.

• Journal of the Korean Electrochemical Society
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• v.7 no.2
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• pp.69-79
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• 2004

To correctly simulate performance characteristics of fuel cells with a modeling method, various physical and chemical phenomena must be considered in fuel cells. In this study, performance characteristics of planar solid oxide fuel cells were simulated by a commercial CFD code, CFD-ACE+. Through simultaneous considerations for mass transfer, heat transfer and charge movement according to electrochemical reactions in the 3-dimensional planar SOFC unit stack, we could successfully predict performance characteristics of solid oxide fuel cells under operation for structural and progress variables. In other words, we solved mass fraction distribution of reactants and products for diffusion and movement, and investigated qualitative and quantitative analysis for performance characteristics in the SOFC unit stack through internal temperature distribution and polarization curve for electrical characteristics. Through this study, we could effectively predict performance characteristics with variables in the unit stack of planar SOFCs and present systematic approach for SOFCs under operation by computer simulation.

• Journal of the Korean Ceramic Society
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• v.43 no.12 s.295
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• pp.823-828
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• 2006

One of the main issues of Solid Oxide Fuel Cells (SOFCs) is to reduce the operating temperature to $750^{\circ}C$ or less. It has advantages of improving the life of component parts and the long-term stability of a system, so the production cost could be decreased. In order to achieve that, the ohmic and polarization loss of a single cell should be minimized first. This paper presents.to fabricate anode-supported single cells with controlling microstructure as a function of particle size and volume of graphite and NiO-YSZ weight ratio. By means of optimizing the manufactural condition through microstructure analysis and performance evaluation, the single cell which had NiO-YSZ=6:4, graphite volume of 24% and graphite size of $75{\mu}m$ as the anode composition showed a distinguished power density of $510mW/cm^2$ at $650^{\circ}C$ and $810mW/cm^2$ at $700^{\circ}C$, respectively.