• 제목/요약/키워드: SOFCs

검색결과 135건 처리시간 0.025초

Fuel-Flexible Anode Architecture for Solid Oxide Fuel Cells

  • Hwan Kim;Sunghyun Uhm
    • 공업화학
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    • 제34권3호
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    • pp.226-240
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    • 2023
  • This paper provides an overview of the trends and future directions in the development of anode materials for solid oxide fuel cells (SOFCs) using hydrocarbons as fuel, with the aim of enabling a decentralized energy supply. Hydrocarbons (such as natural gas and biogas) offer promising alternatives to traditional energy sources, as their use in SOFCs can help meet the growing demands for energy. We cover several types of materials, including perovskite structures, high-entropy alloys, proton-conducting ceramic materials, anode on-cell catalyst reforming layers, and anode functional layers. In addition, we review the performance and long-term stability of cells based on these anode materials and assess their potential for commercial manufacturing processes. Finally, we present a model for enhancing the applicability of fuel cell-based power generation systems to assist in the realization of the H2 economy as the best practice for enabling distributed energy. Overall, this study highlights the potential of SOFCs to make significant progress toward a sustainable and efficient energy future.

저온작동 (600∼650°C) SOFC용 복합밀봉재 제조 및 평가 (Fabrication and Characterization of Composite Sealants for Low Temperature (600∼650°C)SOFCs)

  • 임현엽;김형철;최선희;김혜령;손지원;이해원;이종호
    • 한국세라믹학회지
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    • 제45권12호
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    • pp.802-806
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    • 2008
  • A proper sealant for low temperature SOFCs should show zero or low leak rates to avoid direct mixing of the fuel and oxidant gases or leakage of fuel gas during the operation of SOFCs. Furthermore, it should be chemically and/or mechanically stable in both oxidizing and reducing environments and chemically compatible with other fuel cell components. In the present work, we developed a novel compressed seal gasket of glass-based composite reinforced with ceramic particulate particles, which can efficiently control the viscous flow of glass matrix as well as the crystallization of glass phase. This novel sealing gasket showed excellent gas tightness under very low compressive load which would be suitable for the operation of SOFCs in the temperature range $600{\sim}650^{\circ}C$.

안정적인 SOFC 운전을 위한 디젤 개질기 내 미반응 저탄화수소 제거법 (Methodology for removing unreacted low-hydrocarbons in diesel reformate for stable operation of solid oxide fuel cells)

  • 윤상호;배중면;이상호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.773-776
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    • 2009
  • In this paper, new concept of the diesel fuel processing is introduced for the stable operation of solid oxide fuel cells (SOFCs). Heavier hydrocarbons than $CH_4$, such as ethylene, ethane, propane, and etc., induce the carbon deposition on anode of SOFCs. In the reformate of heavy hydrocarbons (diesel, gasoline, kerosene, and JP-8), concentration of ethylene is usually higher than low hydrocarbons such as ethane, propane, and butane. So, removal of low hydrocarbons (over C1-hydrocarbons), especially ethylene, at the reformate gases is important for stable operation of SOFCs. New methodology as named "post-reformer" is introduced for removing the low hydrocarbons at the reformate gas stream. Catalyst of the NECS-PR4 is selected for post-reforming catalyst because the catalyst of NECS-PR4 shows the high selectivity for removing low hydrocarbons and achieving the high reforming efficiency. The diesel reformer and post-reformer are continuously operated for about 200 hours as integrated mode. The reforming performance is not degraded and low hydrocarbons in the diesel reformate are completely removed.

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Powder Packing Behavior and Constrained Sintering in Powder Processing of Solid Oxide Fuel Cells (SOFCs)

  • Lee, Hae-Weon;Ji, Ho-Il;Lee, Jong-Ho;Kim, Byung-Kook;Yoon, Kyung Joong;Son, Ji-Won
    • 한국세라믹학회지
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    • 제56권2호
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    • pp.130-145
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    • 2019
  • Widespread commercialization of solid oxide fuel cells (SOFCs) is expected to be realized in various application fields with the advent of cost-effective fabrication of cells and stacks in high volumes. Cost-reduction efforts have focused on production yield, power density, operation temperature, and continuous manufacturing. In this article, we examine several issues associated with processing for SOFCs from the standpoint of the bimodal packing model, considering the external constraints imposed by rigid substrates. Optimum compositions of composite cathode materials with high volume fractions of the second phase (particles dispersed in matrix) have been analyzed using the bimodal packing model. Constrained sintering of thin electrolyte layers is also discussed in terms of bimodal packing, with emphasis on the clustering of dispersed particles during anisotropic shrinkage. Finally, the structural transition of dispersed particle clusters during constrained sintering has been correlated with the structural stability of thin-film electrolyte layers deposited on porous solid substrates.

Application of Atomic Layer Deposition to Electrodes in Solid Oxide Fuel Cells

  • Kim, Eui-Hyeon;Hwang, Heui-Soo;Ko, Myeong-Hee;Bae, Seung-Muk;Hwang, Jin-Ha
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.319.1-319.1
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    • 2013
  • Solid oxide fuel cells (SOFCs) have been recognized as one of emerging renewable energy sources, due to minimized pollutant production and high efficiency in operation. The performance of SOFCs is largely dependent on the electrode polarization which involves the oxidation/reduction in cathodes and anodes along with the charge transport of ions and electronic carriers. Atomic layer deposition is based on the alternate chemical surface reaction occurring at low temperatures with high uniformity and superior step coverage. Such features can be extended into the coating of metal oxide and/or metal layer onto the porous materials. In particular, the atomic layer deposition is can manipulated in controlling the charge transport in terms of triple phase boundaries, in order to control artificially the electrochemical polarization in electrodes of SOFC. The current work applied atomic layer deposition of metal oxides intro the electrodes of SOFCs. The corresponding effect was monitored in terms of the electrochemical characterization. The roles of atomic layer deposition in solid oxide fuel cells are discussed towards optimized towards long-term durability at intermediate temperature.

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Solid Oxide Fuel Cells for Power Generation and Hydrogen Production

  • Minh, Nguyen Q.
    • 한국세라믹학회지
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    • 제47권1호
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    • pp.1-7
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    • 2010
  • Solid oxide fuel cells (SOFCs) have been under development for a variety of power generation applications. Power system sizes considered range from small watt-size units (e.g., 50-W portable devices) to very large multi-megawatt systems (e.g., 500-MW base load power plants). Because of the reversibility of its operation, the SOFC has also been developed to operate under reverse or electrolysis mode for hydrogen production from steam (In this case, the cell is referred to as solid oxide electrolysis cell or SOEC.). Potential applications for the SOEC include on-site and large-scale hydrogen production. One critical requirement for practical uses of these systems is long-term performance stability under specified operating conditions. Intrinsic material properties and operating environments can have significant effects on cell performance stability, thus performance degradation rate. This paper discusses potential applications of the SOFC/SOEC, technological status and current research and development (R&D) direction, and certain aspects of long-term performance degradation in the operation of SOFCs/SOECs for power generation/hydrogen production.

Characterization of Ln0.8Sr0.2CoO3-δ (Ln=Gd, Nd, Pr, Sm, or Yb) as Cathode Materials for Low-Temperature SOFCs

  • Choi, Jung-Woon;Kang, Ju-Hyun;Kim, Han-Ji;Yoo, Kwang-Soo
    • 한국세라믹학회지
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    • 제43권12호
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    • pp.758-763
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    • 2006
  • Perovskites with nominal compositions $Ln_{0.8}Sr_{0.2}CoO_{3-\delta}$ (Ln=Gd, Nd, Pr, Sm, or Yb) were fabricated as cathode materials using a solid-state reaction method for low-temperature operating Solid-Oxide Fuel Cells (SOFCs). X-ray diffraction analysis and microstructure observation for the sintered samples were performed. The ac complex impedance was measured in the temperature range of $600-900^{\circ}C$ in air and fitted with a Solartron ZView program. The crystal structure, microstructure, electrical conductivity, and polarization resistance of $Ln_{0.8}Sr_{0.2}CoO_{3-\delta}$ were characterized systematically.

Enhanced Electrochemical Reactivity at Electrolyte/electrode Interfaces of Solid Oxide Fuel Cells with Ag Grids

  • Choi, Mingi;Hwang, Sangyeon;Byun, Doyoung;Lee, Wonyoung
    • 한국세라믹학회지
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    • 제52권5호
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    • pp.356-360
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    • 2015
  • The specific role of current collectors was investigated at the electrolyte/electrode interface of solid oxide fuel cells (SOFCs). Ag grids were fabricated as current collectors using electrohydrodynamic (EHD) jet printing for precise control of the grid geometry. The Ag grids reduced both the ohmic and polarization resistances as the pitch of the Ag grids decreased from $400{\mu}m$ to $100{\mu}m$. The effective electron distribution along the Ag grids improved the charge transport and transfer at the interface, extending the active reaction sites. Our results demonstrate the applicability of EHD jet printing to the fabrication of efficient current collectors for performance enhancement of SOFCs.

Nanomaterials for Advanced Electrode of Low Temperature Solid Oxide Fuel Cells (SOFCs)

  • Ishihara, Tatsumi
    • 한국세라믹학회지
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    • 제53권5호
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    • pp.469-477
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    • 2016
  • The application of nanomaterials for electrodes of intermediate temperature solid oxide fuel cells (SOFC) is introduced. In conventional SOFCs, the operating temperature is higher than 1073 K, and so application of nanomaterials is not suitable because of the high degradation rate that results from sintering, aggregation, or reactions. However, by allowing a decrease of the operating temperature, nanomaterials are attracting much interest. In this review, nanocomposite films with columnar morphology, called double columnar or vertically aligned nanocomposites and prepared by pulsed laser ablation method, are introduced. For anodes, metal nano particles prepared by exsolution from perovskite lattice are also applied. By using dissolution and exsolution into and from the perovskite matrix, performed by changing $P_{O2}$ in the gas phase at each interval, recovery of the power density can be achieved by keeping the metal particle size small. Therefore, it is expected that the application of nanomaterials will become more popular in future SOFC development.