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Статті в журналах з теми "SOECs"
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Dragan, Mirela. "Closing the Loop: Solid Oxide Fuel and Electrolysis Cells Materials for a Net-Zero Economy." Materials 17, no. 24 (December 13, 2024): 6113. https://doi.org/10.3390/ma17246113.
Повний текст джерелаАнотація:
Solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs) represent a promising clean energy solution. In the case of SOFCs, they offer efficiency and minimal to zero CO2 emissions when used to convert chemical energy into electricity. When SOFC systems are operated in regenerative mode for water electrolysis, the SOFCs become solid oxide electrolyzer cells (SOECs). The problem with these systems is the supply and availability of raw materials for SOFC and SOEC components. This raises significant economic challenges and has an impact on the price and scalability of these technologies. Recycling the materials that make up these systems can alleviate these economic challenges by reducing dependence on the supply of raw materials and reducing overall costs. From this point of view, this work is a perspective analysis and examines the current research on the recycling of SOFC and SOEC materials, highlighting the potential paths towards a circular economy. The existing literature on different approaches to recycling the key materials for components of SOFCs and SOECs is important. Mechanical separation techniques to isolate these components, along with potential strategies like chemical leaching or hydrometallurgical and material characterization, to ensure the quality of recycled materials for reuse in new SOFCs and SOECs are important as well. By evaluating the efficiency of various methods and the quality of recovered materials, this study aims to provide valuable insights for advancing sustainable and economically viable SOFC and SOEC technologies within a net-zero economic framework.
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Yoon, Kyung Joong. "(Invited) Degradation Mechanisms and Mitigation Strategies for High-Temperature Solid Oxide Cells." ECS Meeting Abstracts MA2024-02, no. 48 (November 22, 2024): 3367. https://doi.org/10.1149/ma2024-02483367mtgabs.
Повний текст джерелаАнотація:
Solid oxide cell technology represents one of the most efficient methods for energy conversion and has been the subject of extensive research over the past few decades. With significant technological progress, solid oxide fuel cells (SOFCs) have made their way into the market, steadily increasing their market share across various sectors for power generation. Additionally, solid oxide electrolysis cells (SOECs) have attracted substantial interest recently as a highly promising method for the clean production of hydrogen and various chemicals. However, the economic competitiveness of SOFCs and SOECs against conventional fossil fuel-based technologies remains a challenge, with cell and stack lifetimes being a critical factor. Operating at high temperatures, both SOFCs and SOECs are prone to various degradation phenomena, which have been a focal point in their development. SOECs operate under an even harsher environment, leading to additional degradation mechanisms beyond those observed in SOFCs. Studying the degradation mechanisms of SOFCs and SOECs is challenging, primarily due to limitations in characterization techniques. However, recent advancements in characterization techniques for high-temperature phenomena, coupled with theoretical modeling tools, have significantly enhanced our understanding. This progress has provided valuable insights into strategies to prolong the lifetime of SOFC/SOEC cells and stacks. This presentation will review recent advancements in degradation studies and discuss mitigation strategies for major degradation issues, including Cr poisoning, electrode delamination, and Ni agglomeration.
3
Nagatomo, Yohei, Yuya Tachikawa, Stephen Matthew Lyth, Junko Matsuda, and Kazunari Sasaki. "Distribution of Relaxation Times of Fuel Electrodes for Reversible Solid Oxide Cells Fabricated Under Various Conditions." ECS Transactions 112, no. 5 (September 29, 2023): 121–28. http://dx.doi.org/10.1149/11205.0121ecst.
Повний текст джерелаАнотація:
Reversible solid oxide cells (r-SOCs) are electrochemical energy devices that can reversibly switch between power generation by solid oxide fuel cells (SOFCs), and hydrogen production by solid oxide electrolysis cells (SOECs) the reverse operation of SOFCs. For the development of high-performance and durable r-SOCs, it is essential to understand not only the I-V characteristics but also the electrode reaction processes systematically. Here in this study, Ni-GDC cermet fuel electrodes, a composite of Ni and mixed-conducting Gd-doped ceria (GDC), were prepared at different sintering temperatures and electrode thicknesses. Electrochemical impedance measurements and distribution of relaxation times (DRT) analysis were performed in both SOFC and SOEC modes to investigate the influence of fabrication conditions on the fuel electrode reaction processes.
4
Ikegawa, Kazutaka, Kengo Miyara, Yuya Tachikawa, Stephen Matthew Lyth, Junko Matsuda, and Kazunari Sasaki. "Performance and Durability of Solid Oxide Electrolysis Cell Air Electrodes Prepared By Various Conditions." ECS Transactions 109, no. 11 (September 30, 2022): 71–78. http://dx.doi.org/10.1149/10911.0071ecst.
Повний текст джерелаАнотація:
Fuel electrode materials are important for achieving higher performance and durability in solid oxide fuel cells (SOFCs), solid oxide electrolysis cells (SOECs), and reversible solid oxide cells (r-SOCs). On the other hand, the air electrode also faces performance and durability issues. For air electrodes, studies have been conducted on their performance and durability in SOFC operation, but the performance and durability of air electrodes in SOEC and r-SOC operation needs to be investigated in more detail. The electrochemical performance and durability of SOEC and r-SOC are evaluated by conducting electrolysis performance tests of LSCF-based air electrodes with different preparation conditions, electrolysis durability tests at the thermoneutral potential, and a 1000-cycle test in r-SOC mode.
5
Toriumi, Hajime, Katherine Develos Bagarinao, Haruo Kishimoto, and Toshiaki Yamaguchi. "Effect of SOEC Operating Conditions on the YSZ Electrolyte Conductivity." ECS Meeting Abstracts MA2024-02, no. 48 (November 22, 2024): 3431. https://doi.org/10.1149/ma2024-02483431mtgabs.
Повний текст джерелаАнотація:
Solid oxide electrolysis cells (SOECs) using the reverse reaction of solid oxide fuel cells (SOFCs) have attracted attention as green hydrogen production methods and H2O-CO2 co-electrolysis technologies. SOEC has an advantage of higher efficiency than other electrolysis technologies because it can utilize not only electrical energy but also thermal energy. Yttria-stabilized zirconia (YSZ) is often used for the electrolyte materials in SOECs. Generally, in fuel-electrode-supported SOECs utilizing YSZ electrolyte, the NiO-YSZ fuel electrode support and YSZ electrolyte are co-sintered at high temperatures in the range of 1300-1400 oC, so the NiO in the fuel electrode support inevitably diffuses into the YSZ electrolyte. It is known that the NiO dissolution into YSZ accelerates the YSZ conductivity degradation especially under reducing atmosphere, because the fast phase transformation from the cubic (higher conductivity) phase to the tetragonal (lower conductivity) one occurs via nickel reduction in the YSZ lattice [1,2]. Such conductivity degradation has already been well observed in YSZ bulk materials, but in the case of fuel-electrode-supported SOECs, the details of how the conductivity of the Ni-diffused YSZ electrolyte on the fuel-electrode support changes under the SOEC operating conditions are not clear. In this work, in order to clarify the relationship between the conductivity changes of Ni-diffused YSZ electrolytes and SOEC operating conditions of the fuel-electrode-supported cells, we used the fuel-electrode-supported SOECs with Ni-diffused YSZ electrolytes via high temperature co-sintering process. The EIS data at 1.3 V are analyzed by fitting with an equivalent circuit to separate each resistance component. These results will be shown in this presentation. This study is partly based on results obtained from a project, JPNP21022, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References [1] T. Shimonosono, et al., Solid State Ionics 225 (2012) 69-72. [2] W.G. Coors, et al., Solid State Ionics 180 (2009) 246–251.
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Yang, Zhibin, Ze Lei, Ben Ge, Xingyu Xiong, Yiqian Jin, Kui Jiao, Fanglin Chen, and Suping Peng. "Development of catalytic combustion and CO2 capture and conversion technology." International Journal of Coal Science & Technology 8, no. 3 (June 2021): 377–82. http://dx.doi.org/10.1007/s40789-021-00444-2.
Повний текст джерелаАнотація:
AbstractChanges are needed to improve the efficiency and lower the CO2 emissions of traditional coal-fired power generation, which is the main source of global CO2 emissions. The integrated gasification fuel cell (IGFC) process, which combines coal gasification and high-temperature fuel cells, was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO2 emissions. Supported by the National Key R&D Program of China, the IGFC for near-zero CO2 emissions program was enacted with the goal of achieving near-zero CO2 emissions based on (1) catalytic combustion of the flue gas from solid oxide fuel cell (SOFC) stacks and (2) CO2 conversion using solid oxide electrolysis cells (SOECs). In this work, we investigated a kW-level catalytic combustion burner and SOEC stack, evaluated the electrochemical performance of the SOEC stack in H2O electrolysis and H2O/CO2 co-electrolysis, and established a multi-scale and multi-physical coupling simulation model of SOFCs and SOECs. The process developed in this work paves the way for the demonstration and deployment of IGFC technology in the future.
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Wachsman, Eric. "(Invited) Achieving Extreme High Ion-Current Densities in Tailored Materials, Structures, and Interfaces." ECS Meeting Abstracts MA2023-02, no. 46 (December 22, 2023): 3224. http://dx.doi.org/10.1149/ma2023-02463224mtgabs.
Повний текст джерелаАнотація:
Rate capability is a limiting factor in solid oxide fuel cells (SOFCs), solid oxide electrolysis cells (SOECs), and oxide-based solid-state lithium (SSLiBs) and sodium (SSNaBs) batteries. In this presentation we will explain the roles of composition, structure, and interfaces in achieving extremely high current densities, and demonstrate SOFC/SOEC current densities of 5 mA/cm2 at 650°C, and SSNaB and SSLiB current densities of 30 mA/cm2 and 100 mA/cm2, respectively, at room temperature.
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Li, Shian, Zhi Yang, Qiuwan Shen, and Guogang Yang. "A Parametric Study on the Interconnector of Solid Oxide Electrolysis Cells for Co-Electrolysis of Water and Carbon Dioxide." Journal of Marine Science and Engineering 11, no. 5 (May 17, 2023): 1066. http://dx.doi.org/10.3390/jmse11051066.
Повний текст джерелаАнотація:
The shipping industry is trying to use new types of fuels to meet strict pollutant emission regulations and carbon emission reduction targets. Hydrogen is one of the options for alternative fuels used in marine applications. Solid oxide electrolysis cell (SOEC) technology can be used for hydrogen production. When water and carbon dioxide are provided to SOECs, hydrogen and carbon monoxide are produced. The interconnector of SOECs plays a vital role in cell performance. In this study, a 3D mathematical model of cathode-supported planar SOECs is developed to investigate the effect of interconnector rib width on the co-electrolysis of water and carbon dioxide in the cell. The model validation is carried out by comparing the numerical results with experimental data in terms of a polarization curve. The rib width is varied from 0.2 mm to 0.8 mm with an interval of 0.1 mm. It is found that the cell voltage is decreased and then increased as the rib width increases. When the current density is 1 A/cm2, the voltages of SOECs with rib widths of 0.2 mm, 0.6 mm, and 0.8 mm are 1.272 V, 1.213 V, and 1.221 V, respectively. This demonstrates that the best performance is provided by the SOEC with a rib width of 0.6 mm. In addition, the local transport processes of SOECs with different rib widths are presented and compared in detail. This study can provide guidelines for the design of interconnectors of SOECs.
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Zhang, Chi, Bin Lu, Haiji Xiong, Chengjun Lin, Lin Fang, Jile Fu, Dingrong Deng, Xiaohong Fan, Yi Li, and Qi-Hui Wu. "Cobalt-Based Perovskite Electrodes for Solid Oxide Electrolysis Cells." Inorganics 10, no. 11 (October 28, 2022): 187. http://dx.doi.org/10.3390/inorganics10110187.
Повний текст джерелаАнотація:
Recently, many efforts and much attention has been paid to developing environmentally friendly energy. Solid oxide electrolyte cells (SOECs) process in reverse to solid oxide fuel cells (SOFCs) producing hydrogen gas as a green energy source. However, in this application, high-performance catalysts are usually required to overcome the sluggish oxygen evolution reactions (OER) during water decomposition. For this reason, discovery of catalysts with high performance is a crucial issue for the wide application of SOECs. Owning to their inherent activity and adequate stability in electrochemical conditions, perovskite oxides have been intensively employed in SOECs. In this mini review, we summarize the currently available studies concerning the applications of cobalt-based perovskite oxide catalysts in SOECs. Particularly, their structural properties and corresponding electronic structures are discussed based on their electrochemical performance, both experimentally and theoretically.
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Williams, Mark. "Total Energy and Total Power for the SOEC: Critical Role of Area Specific Resistance in Hydrogen Production Rate." ECS Transactions 112, no. 5 (September 29, 2023): 61–66. http://dx.doi.org/10.1149/11205.0061ecst.
Повний текст джерелаАнотація:
This paper develops the governing Total Energy (TE) (kilowatt-hours per kilogram hydrogen) and Total Power (TP) equations for Solid Oxide ElectrolyzerCells (SOECs) and Solid Oxide Fuel Cells (SOFCs). The TE equation includes heat input, exergetic flows, enthalpy of vaporization, pressurization, heat loss, area specific resistance (ASR), etc. The TE equation developed, as it would happen, correlates well with the Idaho National Laboratory (INL) proven SOEC performance of 45 kilowatt-hours per kilogram hydrogen at 20 bars and 725 K. TE is the key performance equation necessary for designing, predicting, and planning for SOEC and SOFC performance and cost. The ASR has a critical role in SOEC TE and TP. The ASR and the targets for ASR necessary to meet important DOE performance targets are discussed.
Дисертації з теми "SOECs"
1
Ramasamy, Devaraj. "Extension of electrochemically active sites in SOFCs and SOECs." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/14813.
Повний текст джерелаАнотація:
Doutoramento em Nanociências e NanotecnologiaSolid oxide fuel (SOFCs) and electrolyzer (SOECs) cells have been promoted as promising technologies for the stabilization of fuel supply and usage in future green energy systems. SOFCs are devices that produce electricity by the oxidation of hydrogen or hydrocarbon fuels with high efficiency. Conversely, SOECs can offer the reverse reaction, where synthetic fuels can be generated by the input of renewable electricity. Due to this similar but inverse nature of SOFCs and SOECs, these devices have traditionally been constructed from comparable materials. Nonetheless, several limitations have hindered the entry of SOFCs and SOECs into the marketplace. One of the most debilitating is associated with chemical interreactions between cell components that can lead to poor longevities at high working temperatures and/or depleted electrochemcial performance. Normally such interreactions are countered by the introduction of thin, purely ionic conducting, buffer layers between the electrode and electrolyte interface. The objective of this thesis is to assess if possible improvements in electrode kinetics can also be obtained by modifying the transport properties of these buffer layers by the introduction of multivalent cations. The introduction of minor electronic conductivity in the surface of the electrolyte material has previously been shown to radically enhance the electrochemically active area for oxygen exchange, reducing polarization resistance losses. Hence, the current thesis aims to extend this knowledge to tailor a bi-functional buffer layer that can prevent chemical interreaction while also enhancing electrode kinetics.The thesis selects a typical scenario of an yttria stabilized zirconia electrolyte combined with a lanthanide containing oxygen electrode. Gadolinium, terbium and praseodymium doped cerium oxide materials have been investigated as potential buffer layers. The mixed ionic electronic conducting (MIEC) properties of the doped-cerium materials have been analyzed and collated. A detailed analysis is further presented of the impact of the buffer layers on the kinetics of the oxygen electrode in SOFC and SOEC devices. Special focus is made to assess for potential links between the transport properties of the buffer layer and subsequent electrode performance. The work also evaluates the electrochemical performance of different K2NiF4 structure cathodes deposited onto a peak performing Pr doped-cerium buffer layer, the influence of buffer layer thickness and the Pr content of the ceria buffer layer. It is shown that dramatic increases in electrode performance can be obtained by the introduction of MIEC buffer layers, where the best performances are shown to be offered by buffer layers of highest ambipolar conductivity. These buffer layers are also shown to continue to offer the bifunctional role to protect from unwanted chemical interactions at the electrode/electrolyte interface.
As pilhas de combustível e eletrolisadores de óxido sólido (PCOSs e EOSs) têm sido promovidas a tecnologias promissoras para estabelecer o abastecimento de combustível e sua utilização futura em sistemas de energia limpa. As PCOSs são dispositivos que produzem energia elétrica pela oxidação de combustíveis como o hidrogénio ou de hidrocarbonetos de elevada eficiência. Alternativamente, as EOSs funcionam de maneira inversa, na qual podem ser gerados combustíveis sintéticos ao fornecer energia eléctrica renovável ao sistema. É, pois, devido a esta natureza semelhante e ainda que inversa, que estes dispositivos têm sido tradicionalmente construídos a partir de materiais compatíveis. No entanto, a entrada no mercado destas tecnologias encontra-se ainda condicionada por diversos factores. Um dos mais limitantes, está associado a problemas de estabilidade química entre os constituintes da célula, que podem reduzir a longevidade a elevadas temperaturas de operação e/ou a um desempenho eletroquímico insuficiente. Normalmente, tais problemas de compatibilidade são minimizados pela introdução de uma camada de proteção muito fina constituída por um material condutor puramente iónico, na interface elétrodo/eletrólito. Deste modo, o objetivo deste trabalho é avaliar se modificando as propriedades de transporte destas camadas de proteção se pode conduzir ao aumento das propriedades de cinética do elétrodo, através da introdução de catiões polivalentes. A introdução de condutividade eletrónica menor na superfície do electrólito foi anteriormente relatada apresentando uma melhoria muito considerável das zonas eletroquimicamente activas para a permuta de oxigénio, reduzindo, desta forma, as perdas de resistência de polarização.Assim, esta dissertação tem por objetivo desenvolver este conhecimento para adaptar uma camada de proteção bifuncional que consiga evitar os problemas de interação química e ao mesmo tempo aumentar a cinética dos elétrodos. Esta dissertação apresenta um cenário típico de um eletrólito à base de zircónia estabilizada com ítrio combinado com um elétrodo de oxigénio contendo lantanídeos. Foram investigados como materiais de proteção, os sistemas de céria dopada com gadolínio, térbio e praseodímio. As propriedades inerentes à condução eletrónica e iónica mista (MIEC) dos materiais dopados foram analisadas e agrupadas. Posteriormente, foi realizada uma análise detalhada sobre o impacto das camadas de proteção na cinética do elétrodo de oxigénio em dispositivos PCOS e EOS. Foi dada especial atenção às potenciais relações entre as propriedades de transporte da camada proteção e subsequente desempenho do elétrodo. O trabalho também avalia o desempenho eletroquímico de cátodos de K2NiF4 com diferentes estruturas, depositadas sobre a camada de proteção que apresentou melhor desempenho, isto é, a céria dopada com praseodímio, assim como a influência da espessura da camada e da fração de Pr presente na céria. Demonstrou-se que a introdução de camadas de proteção à base de MIECs levou a um aumento drástico no desempenho do elétrodo, nomeadamente pelos MIECs de maior condutividade ambipolar. Estas camadas de proteção utlizadas provaram ser também eficazes em manter o papel de inibidores de interactividade química na interface elétrodo/eletrólito.
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Sharma, Vivek Inder. "Degradation mechanisms in La₀.₈Sr₀.₂CoO₃ as oxygen electrode bond layer in solid oxide electrolytic cells (SOECs)." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/57886.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 100-104).
High temperature steam electrolysis is an efficient process and a promising technology to convert electricity and steam or a mixture of steam and CO₂, into H₂ or syn-gas (H₂2 + CO) respectively. It is carried out in Solid Oxide Electrolytic Cells (SOECs). At the high temperature of operation, above 8000[degree] C, loss in the rate of hydrogen (or syn gas) production by SOECs has been observed. This loss of performance has been a scientific and technological challenge. The goal of this thesis is to identify the mechanisms for the loss in the electrochemical performance of SOECs due to the oxygen electrode and bond layer degradation. Our specific research objectives were focused on two main mechanisms: 1) Cr transport into the oxygen electrode and bond layer, and 2) Long-range segregation of cations in the bond layer. For SOECs provided by Ceramatec Inc. for this analysis, La₀.₈Sr₀.₂CoO₃ (LSC) was the bond layer and A₀.₈Sr₀.₂MnO₃ (ASM*) was the oxygen electrode, both comprised of perovskite structure. The approach in thesis integrated complementary spectroscopy and microscopy techniques in a novel manner to carry out the 'post-mortem' analysis of SOECs from a high level to a high resolution. Raman spectroscopy was employed to identify secondary phases on the top surface of LSC near the interconnect interphase. Surface chemistry and microstructure of the air electrode and the bond layer was studied using scanning Auger Electron Spectroscopy (AES) with nano-probe capability.
(cont.) High-resolution analysis of the cation distribution in the bulk of the LSC bond layer was achieved by employing Energy Dispersive X-ray Analysis (EDX) coupled with Scanning Transmission Electron Microscopy (STEM). Electrochemical treatment and characterization was performed to isolate the mechanism(s) governing the long-range segregation of cations, leading to the dissociation of the LSC bond layer. Less-conducting, secondary phases of Cr₂O₃, LaCrO₃, La₂CrO₆ and Co₃0₄ were identified on the top surface of LSC bond layer. The bond layer exhibited: 1) presence of Cr, with average Cr-fraction of approximately 0.07 at the surface of its grains, and 2) surface composition variation locally, with La/Co ranging widely from 0.67 to 16.37 compared to the stoichiometric La/Co value of 0.8. Sr and Co cations migrated from the bond layer structure to the LSC/interconnect interface, over a distance of 10-20 microns. Furthermore, STEM/EDX results showed the presence of phase separated regions at the nano-scale rich in Cr and La but lacking Co, and vice-versa. This indicates the dissociation of bond layer bulk structure at nano-scale. Cr fraction in LSC bulk varied from 10 to 33%, which is higher than the average Cr-content at the surface of LSC grains. The maximum Sr fraction observed in LSC bulk was 4.16%, confirming the migration of Sr to LSC/interconnect interface.
(cont.) We hypothesize that the long-range transport of Sr, Co, and Cr cations can be caused by two primary mechanisms: 1) Driven by Cr-related thermodynamics, where the Crcontaning species (i.e. at the vicinity of the interconnect) could thermodynamically favor the presence of select cations (i.e. Sr and Co) at the region interfacing the interconnect. 2) Driven by the electronic or oxygen ion current. To test these hypotheses and to isolate the governing mechanism, we simulated controlled electrochemical conditions on reference cells having ASM electrodes coated with LSC, on both sides of SSZ electrolyte, without any Cr-containing layers on the LSC bond layer. The reference cells degraded even in the absence of Cr. AES results showed that the microstructure and surface composition of the reference cells stayed stable and uniform upon the electrochemical treatment, in spite of the degradation. Thus, this thesis concludes that the Cr-related thermodynamics could be the dominant mechanism driving the uneven dissociation and segregation of cations in LSC as observed in the stack cells. As a mechanism for Cr-deposition in the LSC bond layer, we suggest that a thermodynamically-favored reaction between the La-enriched phase (at the surface of the LSC grains) and the volatile Cr-species (Cr0₃ and CrO₂(OH)) is responsible for the formation of poorly-conducting secondary phases. This interaction is likely to be limited by the presence of the segregated La-O-species which can serve as a nucleation agent for this reaction.
by Vivek Inder Sharma.
S.M.
3
Zhang, Jinming. "Surface chemistry study on the SOEC electrodes during high-temperature H2O electrolysis." Electronic Thesis or Diss., Strasbourg, 2024. https://publication-theses.unistra.fr/public/theses_doctorat/2024/ZHANG_Jinming_2024_ED222.pdf.
Повний текст джерелаАнотація:
Cette thèse se concentre sur les performances électrochimiques et la chimie de surface des cellules d'électrolyse à oxyde solide avancées (SOEC), avec une attention particulière sur le comportement des électrodes Ni/YSZ lors de l'électrolyse de l'eau. Les SOEC présentent un potentiel considérable pour la production d'hydrogène par électrolyse de l'eau et le stockage d'énergie, tandis que les piles à combustible à oxyde solide (SOFC) utilisent l'hydrogène pour la production d'électricité. Compte tenu de l'efficacité économique, de la compatibilité thermique et de la haute conductivité des composites à base de nickel, largement utilisés dans les applications industrielles, cette recherche se concentre sur l'amélioration de ces matériaux grâce à la modification de surface. À l'aide de la spectroscopie de photoélectrons par rayons X à pression quasi ambiante (NAP-XPS), l'interaction entre les électrodes Ni/YSZ et la vapeur d'eau a été étudiée dans des conditions de circuit ouvert et de polarisation. Des modifications ont été apportées aux cathodes poreuses traditionnelles en Ni/YSZ afin d'observer directement les zones fonctionnelles proches de l'électrolyte YSZ. Les résultats ont révélé des changements dynamiques dans les états d'oxydation et la composition du Ni/YSZ dans des atmosphères de H2 et de H2O. En outre, cette étude met en lumière l'impact de l'oxydation des électrodes sur la dégradation pendant l'électrolyse et souligne la relation entre l'état d'oxydation de la surface du nickel et les performances électrochimiques de la cellule. Des nanoparticules (NP) à base de cérium ont été introduites pour modifier la surface des électrodes Ni/YSZ. Deux types de NP — le cérium dopé au nickel (NiCeOx) et le cérium non dopé (CeOy) — ont été synthétisés et utilisés pour imprégner des électrodes métalliques Ni/YSZ préfabriquées. L'étude comparative a montré que le NiCeOx présentait des performances supérieures en raison d'une meilleure dispersion et d'une taille de particules plus réduite. Les résultats obtenus par synchrotron ont également révélé que le dopage au nickel modifiait les propriétés rédox du cérium, conduisant à une réduction plus forte de Ni/YSZ par rapport à CeOy, ce qui a augmenté le nombre de sites actifs et amélioré l'efficacité de l'électrolyse. De plus, des essais expérimentaux impliquant des nanoparticules de cérium dopé au vanadium et au cobalt ont été présentés, bien que les améliorations de performances aient été limitées. Enfin, les surface des électrodes La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) ont été étudiés, en se concentrant sur la ségrégation du Sr. L'étude a également examiné le Pr6O11 en tant que catalyseur électrochimique alternatif pour les applications SOEC, démontrant son potentiel. En somme, cette recherche souligne l'impact significatif des modifications de surface des nanoparticules sur les performances électrochimiques des électrodes dans l'électrolyse de l'eau, révélant des améliorations notables en termes d'efficacité et de stabilité. La combinaison d'une conception innovante des matériaux et de techniques de caractérisation avancées offre des perspectives précieuses pour le développement de solutions énergétiques durablesThis thesis focuses on the electrochemical performance and surface chemistry of advanced Solid Oxide Electrolysis Cells (SOECs), with particular emphasis on the behavior of Ni/YSZ electrodes in water electrolysis. SOECs hold significant potential for hydrogen production through water electrolysis and energy storage, while Solid Oxide Fuel Cells (SOFCs) use hydrogen for power generation. Given the cost-effectiveness, thermal compatibility, and high conductivity of nickel-based composites, widely used in industrial applications, this research concentrates on improving these materials through surface modification. Using Near Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS), the interaction between Ni/YSZ electrodes and water vapor under both open-circuit and polarization conditions was investigated. Modifications to traditional porous Ni/YSZ cathodes were made to directly observe the functional electrode areas near the YSZ electrolyte. Results revealed dynamic changes in the oxidation states and composition of Ni/YSZ in H2 and H2O atmospheres. Additionally, the study emphasizes the impact of electrode oxidation on degradation during electrolysis and highlights the relationship between the nickel surface oxidation state and the cell’s electrochemical performance. Cerium-based nanoparticles (NPs) were introduced to modify the surface of Ni/YSZ electrodes. Two types of NPs—Ni-doped ceria (NiCeOx) and undoped ceria (CeOy)—were synthesized and used to impregnate pre-fabricated Ni/YSZ cermet electrodes. The comparative study demonstrated that NiCeOx exhibited superior performance due to enhanced dispersion and reduced particle size. Synchrotron results further showed that Ni doping altered the redox properties of ceria, leading to stronger reduction of Ni/YSZ compared to CeOy, which increased the number of active sites and improved electrolysis efficiency. Additionally, the thesis presents experimental trials involving vanadium and cobalt-doped ceria nanoparticles, although their performance enhancements were limited. Finaly the surface state of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) electrodes were explored, focusing on Sr segregation. The study also examined Pr6O11 as a potential alternative electrocatalyst for SOEC applications. Overall, the research highlights the significant impact of nanoparticle surface modifications on the electrochemical performance of electrodes in water electrolysis, revealing substantial improvements in both efficiency and stability. The combination of innovative material design and advanced characterization techniques offers valuable insights for the future of sustainable energy solutions
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Vibhu, Vaibhav. "Stabilité et vieillissement des études de nickelates base praséodyme comme cathodes pour oxyde solide piles à combustible." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0017/document.
Повний текст джерелаАнотація:
Ce travail de thèse est consacré à l’étude des nickelates La2-xPrxNiO4+δ, comme nouveaux matériauxde cathodes pour piles à combustible haute température, SOFC, et en particulier à la caractérisationde leur stabilité chimique et leur comportement en fonctionnement. En effet, du fait de leurpropriété de conduction mixte ionique et électronique, MIEC, les nickelates de structure typeK2NiF4, Ln2NiO4+δ (Ln = La, Pr, Nd), correspondant au terme n = 1 de la série de Ruddlesden-Popper (An+1MnO(3n+1)), sont des matériaux prometteurs pour des fonctionnements à températureintermédiaire, IT-SOFC (T < 800 °C). Compromis entre la stabilité chimique de La2NiO4+δ et lestrès bonnes performances électrochimiques de Pr2NiO4+δ, les phases La2-xPrxNiO4+δ, ont étésynthétisées et leurs propriétés physico-chimiques, de transport et électrochimiques ont étédéterminées. L’étude approfondie des caractéristiques des électrodes par spectroscopied’impédance en cellules symétriques a été réalisée à courant nul et sous polarisation anodique etcathodique sur des périodes d’un mois. De façon surprenante, même après la dissociation complètede Pr2NiO4+δ en PrNiO3-δ, Pr4Ni3O10+δ et Pr6O11, la résistance de polarisation ne montre pas dechangement significatif. L’étude de PrNiO3-δ et Pr4Ni3O10+δ, comme matériau de cathode pour pilesà combustible, démontre l’excellent comportement de la phase Pr4Ni3O10+δ et ceci en cellulesymétrique (Rp (Pr4Ni3O10+δ) = Rp (Pr2NiO4+δ) = 0.15 Ω.cm² à 600 ° C) et cellule complète (1.6W.cm-2 at 800 °C)This PhD work is dedicated to stability and ageing studies of Praseodymium based nickelates ascathodes for Solid Oxide Fuel Cells (SOFCs). With this respect Ln2NiO4+δ (Ln=La, Pr or Nd)compounds with the K2NiF4 type structure act as alternative cathode materials for IT-SOFC due totheir mixed ionic and electronic conductivity (i.e. MIEC properties). Pr2NiO4+δ shows excellentelectrochemical properties at intermediate temperature (i.e. low polarization resistance Rp value, Rp= 0.03 Ω.cm² at 700 °C), while La2NiO4+δ exhibits higher chemical stability. So, the properties ofLa2-xPrxNiO4+δ nickelates were investigated with the aim to find best compromise between chemicalstability and electrochemical performances. After synthesis, the physical and chemical properties aswell as their transport and electrochemical properties have been determined. Measurements of thepolarization resistance of symmetrical half-cells have been carried out by impedance spectroscopy.Then, the chemical stability and the electrochemical performance of the materials have been studiedfor duration up to one month. As an interesting point, even after complete dissociation of Pr2NiO4+δinto PrNiO3-δ,Pr4Ni3O10+δ and Pr6O11, the polarization resistance does not show significant change.So finally, two new materials PrNiO3-δ and Pr4Ni3O10+δ were investigated as SOFCs cathodeshowing very promising results for Pr4Ni3O10+δ in symmetrical cell (Rp (Pr4Ni3O10+δ) = Rp(Pr2NiO4+δ) = 0.15 Ω.cm² à 600 ° C) and complete cell (1.6 W.cm-2 at 800 °C)
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Frank, Nadine P. R. "Umsetzung von Kohlenwasserstoffen in SOFCs." München Dr. Hut, 2010. https://mediatum2.ub.tum.de/node?id=808645.
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Russi, Luigi. "modeling the pressure drop and thermal profile of a novel solid oxide fuel cell stack design with a homogenized approach." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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Le celle a combustibile a ossidi solidi (SOFCs) rappresentano una tecnologia chiave in uno scenario di decarbonizzazione delle attività umane per i prossimi anni.
Gli stack attualmente disponibili presentano elevati gradienti di temperatura e grandi perdite di carico attraverso lo stack, così come distribuzioni di corrente disuniformi, problemi di perdita di contatto e di deterioramento.
Un innovativo design dello stack, detto"Chessboard", è stato ideato al DTU Energy.
La determinazione dei campi di temperatura, pressione e velocità nello stack tramite simulazione risulta fondamentale per valutare la qualità di un certo design. Infatti non sempre è possibile misurare sperimentalmente grandezze fisiche locali all'interno dello stack.
In questo lavoro un modello tridimensionale (3D) dello stack è stato costruito. L'approccio modellistico utilizzato si basa sulla tecnica di omogenizzazione. Un metodo efficiente a livello computazionale basato sull'utilizzo di una geometria semplificata, ma con proprietà termofisiche anisotropiche che rispecchino la vera geometria dello stack per reincrementare il livello di dettaglio.
Fra tutte le fisiche che descrivono i fenomeni in una SOFC, solo il moto dei fluidi e la trasmissione del calore sono effettivamente risolte dal modello nell'attuale stadio di sviluppo, mentre i fenomeni elettrochimici sono definiti come parametri in ingresso.
Una volta impostato il modello, è stato eseguito uno studio parametrico, con lo scopo di ottenere i profili di temperatura e pressione in funzione delle dimensioni dello stack, dell'eccesso d'aria, della pressione in ingresso dell'aria e della dimensione dei pori. Individuando quindi una finestra di esercizio sicura per i 4 parametri considerati.
Dai risultati si evince che è possibile trovare diverse combinazioni di parametri che soddisfino l'obiettivo di progetto dato da limiti sui materiali costituenti lo stack, tutto questo con dei tempi di risoluzione nell'ordine dei minuti.
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Fagg, Duncan Paul. "Anodes for SOFCs (solid oxide fuel cells)." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU082955.
Повний текст джерелаАнотація:
The success of Solid Oxide Fuel Cells (S.O.F.C) rests heavily on material selection. The performances of several compounds were investigated as possible anode materials, starting with reduced titanates such as the magnesium titanate and zirconium titanate. These compositions, although possessing many qualities beneficial for use as an anode material, were found to be too unstable for practical use. For this reason further work concentrated on stable, zirconia based, compounds with exhibited mixed conduction under reducing atmospheres. The mobility of electronic carriers is considered to be much higher than that of ionic defects, therefore, promising mixed conductors can be formed by doping a good ionic conductor with a small concentration of transition metal ions. Zirconia based mixed conductors were studied for two reasons. Firstly, zirconia stabilised in the cubic defect fluorite structure, exhibits a high level of ionic conductivity. Secondly, it is the most common electrolyte material for an S.O.F.C. An anode based on zirconia would, therefore, be expected to offer a good physical compatibility with the electrolyte material and to exhibit a high ionic contribution to total conductivity. Large defect fluorite solid solutions in the systems Y2O3-ZrO2-Nb2O5, Yb2O3-ZrO2-Nb2O5 and CaO-ZrO2-Nb2O5 were established, which enabled the effects of composition, dopant size and charge on conduction to be investigated. These effects were shown to be linked to structure. From these results and comparisons with the Y2O3-ZrO2-TiO2 system, optimum, mixed conducting, compositions were established. The sample Y0.25Ti0.15Zr0.60O1.875 exhibited the best mixed conducting properties to date, obtained for compositions based on zirconia.
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Zianbetov, Eldar. "Horlogerie distribuée pour les SoCs synchrones." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-01053729.
Повний текст джерелаАнотація:
Cette thèse aborde le problème de génération d'horloge globale dans les SoCs complexes dans le contexte des technologies CMOS profondément submicroniques. Actuellement, afin de contourner les difficultés liées aux techniques classiques de distribution d'horloge (p.ex. arbre, grille) dans les systèmes synchrones, les concepteurs qui désirent de se rendre sur le paradigme Synchronisation Globale se tournent vers les techniques de synchronisation rompant avec les approches classiques (par exemple oscillateurs distribués, les ondes stationnaires , oscillateurs couplés, les retards programmables). Cette étude s'inscrit dans ce courant. Dans ce travail, nous avons étudié et mis au point un système de génération d'horloge sur puce destiné à un SoC synchrone de haute fiabilité. Cette architecture est basée sur un réseau d'oscillateurs couplés en phase et en fréquence à l'aide d'un réseaux de boucles à verrouillage de phase tout numériques (ADPLLs). Pendant cette recherche nous avons mis au point les spécifications et choisi une architecture de réseau. Un modèle théorique du système a été mis en place en collaboration avec CEA-LETI et Supélec dans le cadre du projet ANR HODISS. Nous avons analysé le comportement du système dans les simulations sur différents niveaux d'abstraction, en enquêtant des conditions de stabilité de son fonctionnement synchrone. L'ADPLL a été proposé comme un nœud élémentaire du réseau de synchronisation distribuée. L'utilisation d'ADPLL permet de contourner les difficultés d'implémentation, qui sont généralement associées à PLL analogique. Nous avons conçu les blocs principaux de l'ADPLL: un oscillateur à commande numérique (Digitally-Controlled Oscillator, DCO), un détecteur de phase/fréquence (PFD) et un bloc de traitement d'erreur. Une technique de conception basée sur les cellules a été adapté pour le développement d'oscillateur. Cette technique réduit considérablement la complexité de l'implémentation de l'oscillateur. Les autres blocs ont été conçus en utilisant un flot de conception numérique commun. Afin de réduire les risques associés à l'implémentation de silicium, le système a été validé dans une plate-forme de prototypage FPGA. Les résultats des mesures ont montré que la synchronisation de réseau se comporte comme prédit par la théorie et ainsi que les simulations. Deux circuits de prototypage ont été conçus, mis en œuvre et testés dans une technologie CMOS 65 nm de STMicroelectronics. La première puce est une preuve de concept d'un DCO conçu très linéaire et monotone. Les paramètres mesurés de l'oscillateur sont conformes aux spécifications. La performance mesurée a démontré une gigue de moins de 15 ps rms, en consommant 6.2 mW/GHz @ 1.1 V. La plage de réglage de l'oscillateur est 999-2480 MHz avec une résolution de 10 bits. La deuxième puce est un réseau d'horloge avec 4x4 nœuds qui se compose de 16 ADPLLs distribués. Chacun d'entre eux utilise les blocs conçu précédemment: DCO, PFD et bloc de traitement d'erreur. Les expérimentes ont montré que la technique proposée de génération d'horloge distribuée est réalisable sur une puce réelle CMOS. La performance mesurée démontre l'erreur de synchronisation entre les oscillateurs voisins moins de 60 ps, alors que la consommation d'énergie est 98.47 mW/GHz.
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Barry, A. C. "Regulation of TCR signalling by SOCS." Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479241.
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Stanislowski, Michael. "Verdampfung von Werkstoffen beim Betrieb von Hochtemperaturbrennstoffzellen (SOFCs)." Jülich : Forschungszentrum, Zentralbibliothek, 2006. http://d-nb.info/98787103X/34.
Повний текст джерелаКниги з теми "SOECs"
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1946-, Rosen Michael, and Rayner Shoo, eds. Pilly soems. London: A & C Black, 1994.
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Monsonís, Octavi. Solcs en l'aigua. Valencia: Brosquil Edicions, 2003.
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Braddon, Russell. Nancy Wake: SOE's greatest heroine. Phoenix Mill, UK: Sutton Pub., 2005.
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Braddon, Russell. Nancy Wake: SOE's greatest heroine. Phoenix Mill, UK: Sutton Pub., 2005.
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1963-, Oud Pauline, ed. Een dansje voor Soes. Assen: Maretak, 2008.
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Birkelund, Peter. Faldskærmsfolk: SOE's arbejde i Danmark 1941-45. [Copenhagen]: Frihedsmuseets venners forlag, 1986.
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1957-, Hoogstad Alice, ed. Met poes Soes naar oom Mik. Tilburg: Zwijsen, 2004.
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Stanislowski, Michael. Verdampfung von Werkstoffen beim Betrieb von Hochtemperaturbrennstoffzellen (SOFCs). Jülich: Schriften des Forschungszentrums, 2006.
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Holló, Gyorgy. The state and SOEs in Hungarian privatization. Cambridge, MA: Minda de Gunzburg Center for European Studies, Harvard University, 1992.
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Valentine, Ian. Station 43: Audley End House and SOE's Polish section. Phoenix Mill, Gloucestershire: Sutton, 2004.
Знайти повний текст джерелаЧастини книг з теми "SOECs"
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Vibhu, Vaibhav, Amir Reza Hanifi, Thomas H. Etsell, and Jean-Marc Bassat. "Oxygen Electrode Materials for Solid Oxide Electrolysis Cells (SOECs)." In Lecture Notes in Energy, 59–89. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-22508-6_4.
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Khan, Muhammad Shirjeel, and Ruth Knibbe. "Fuel Electrode Materials for Solid Oxide Electrolysis Cells (SOECs)." In Lecture Notes in Energy, 91–115. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-22508-6_5.
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Strebovsky, Julia, Jana Zimmer, and Alexander H. Dalpke. "SOCS." In Encyclopedia of Signaling Molecules, 5061–68. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-67199-4_625.
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Strebovsky, Julia, Jana Zimmer, and Alexander H. Dalpke. "SOCS." In Encyclopedia of Signaling Molecules, 1–8. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4614-6438-9_625-1.
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Dempsey, Brian R., Anne C. Rintala-Dempsey, Gary S. Shaw, Yuan Xiao Zhu, A. Keith Stewart, Jaime O. Claudio, Constance E. Runyan, et al. "SOCS." In Encyclopedia of Signaling Molecules, 1753–59. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-0461-4_625.
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Lynch, Gordon S., David G. Harrison, Hanjoong Jo, Charles Searles, Philippe Connes, Christopher E. Kline, C. Castagna, et al. "SOCS." In Encyclopedia of Exercise Medicine in Health and Disease, 797. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-540-29807-6_3049.
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Starr, Robyn, and Douglas J. Hilton. "SOCS Proteins." In Signal Transducers and Activators of Transcription (STATs), 55–73. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-017-3000-6_5.
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Chakravarthi, Veena S., and Shivananda R. Koteshwar. "Application-specific SOCs." In System on Chip (SOC) Architecture, 49–63. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-36242-2_4.
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Chakravarthi, Veena S., and Shivananda R. Koteshwar. "Storage in SOCs." In System on Chip (SOC) Architecture, 65–73. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-36242-2_5.
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Shao, Zongping, and Moses O. Tadé. "Cathodes for IT-SOFCs." In Green Chemistry and Sustainable Technology, 59–126. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-52936-2_3.
Повний текст джерелаТези доповідей конференцій з теми "SOECs"
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Giridhar, Nishant V., Debangsu Bhattacharyya, Douglas A. Allan, Stephen E. Zitney, Mingrui Li, and Lorenz T. Biegler. "Optimization of Solid Oxide Electrolysis Cell Systems Accounting for Long-Term Performance and Health Degradation." In Foundations of Computer-Aided Process Design, 448–54. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.177040.
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This study focuses on optimizing solid oxide electrolysis cell (SOEC) systems for efficient and durable long-term hydrogen (H2) production. While the elevated operating temperatures of SOECs offer advantages in terms of efficiency, they also lead to chemical degradation, which shortens cell lifespan. To address this challenge, dynamic degradation models are coupled with a steady-state, two-dimensional, non-isothermal SOEC model and steady-state auxiliary balance of plant equipment models, within the IDAES modeling and optimization framework. A quasi-steady state approach is presented to reduce model size and computational complexity. Long-term dynamic simulations at constant H2 production rate illustrate the thermal effects of chemical degradation. Dynamic optimization is used to minimize the lifetime cost of H2 production, accounting for SOEC replacement, operating, and energy expenses. Several optimized operating profiles are compared by calculating the Levelized Cost of Hydrogen (LCOH).
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Milobar, Daniel G., Peiwen Li, and James E. O’Brien. "Analytical Study, 1-D Optimization Modeling, and Testing of Electrode Supported Solid Oxide Electrolysis Cells." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18261.
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The need for an infrastructure to provide hydrogen as a next generation energy carrier is ever increasing. High temperature solid oxide electrolysis cells (SOECs) have been proven to be a viable technology in the production of hydrogen [1]. With the increasing use of SOECs in various operating environments it is important to be able to specify the best SOEC for any given situation. We have developed a straightforward model to estimate cell performance in a timely and inexpensive manner. Composite electrode planer type SOEC models have been developed previously. It is a common assumption that all electrochemical reactions in these cells occur at the interface of the electrolyte and the electrode [2]. It has been shown by S. Gewies et al. [3] that the reactions occurring throughout a Ni/YSZ cermet electrode occur in a nonlinear fashion. Our one dimensional model has been developed to optimize SOECs with composite electrodes. This model takes into account ohmic, activation, and concentration polarizations. The electrochemical reaction that occurs within the electrode functional layers has been accounted for in the calculation of the concentration polarization. This is believed to give a more realistic view of the mass transfer that occurs in SOECs with composite electrodes via a simple and straightforward 1-D model.
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Sohal, M. S., J. E. O’Brien, C. M. Stoots, V. I. Sharma, B. Yildiz, and A. Virkar. "Degradation Issues in Solid Oxide Cells During High Temperature Electrolysis." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33332.
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Idaho National Laboratory (INL) is performing high-temperature electrolysis (HTE) research to generate hydrogen using solid oxide electrolysis cells (SOECs). The project goals are to address the technical and degradation issues associated with the SOECs. This paper provides a summary of ongoing INL and INL-sponsored activities aimed at addressing SOEC degradation. These activities include stack testing, post-test examination, degradation modeling, and issues that need to be addressed in the future. Major degradation issues relating to solid oxide fuel cells (SOFC) are relatively better understood than those for SOECs. Some of the degradation mechanisms in SOFCs include contact problems between adjacent cell components, microstructural deterioration (coarsening) of the porous electrodes, and blocking of the reaction sites within the electrodes. Contact problems include delamination of an electrode from the electrolyte, growth of a poorly (electronically) conducting oxide layer between the metallic interconnect plates and the electrodes, and lack of contact between the interconnect and the electrode. INL’s test results on HTE using solid oxide cells do not provide clear evidence as to whether different events lead to similar or drastically different electrochemical degradation mechanisms. Post-test examination of the SOECs showed that the hydrogen electrode and interconnect get partially oxidized and become nonconductive. This is most likely caused by the hydrogen stream composition and flow rate during cooldown. The oxygen electrode side of the stacks seemed to be responsible for the observed degradation because of large areas of electrode delamination. Based on the oxygen electrode appearance, the degradation of these stacks was largely controlled by the oxygen electrode delamination rate. Virkar et al. [19–22] have developed a SOEC model based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic nonequilibrium. This model is under continued development. It shows that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential within the electrolyte. The chemical potential within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just under the oxygen electrode (anode)/electrolyte interface, leading to electrode delamination. This theory is being further refined and tested by introducing some electronic conduction in the electrolyte.
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Zhang, Xiaoyu, James E. O’Brien, Robert C. O’Brien, Joseph J. Hartvigsen, Greg Tao, and Nathalie Petigny. "Recent Advances in High Temperature Electrolysis at Idaho National Laboratory: Stack Tests." In ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2012 6th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fuelcell2012-91049.
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High temperature steam electrolysis is a promising technology for efficiently sustainable large-scale hydrogen production. Solid oxide electrolysis cells (SOECs) are able to utilize high temperature heat and electric power from advanced high-temperature nuclear reactors or renewable sources to generate carbon-free hydrogen at large scale. However, long term durability of SOECs needs to be improved significantly before commercialization of this technology. A degradation rate of 1%/khr or lower is proposed as a threshold value for commercialization of this technology. Solid oxide electrolysis stack tests have been conducted at Idaho National Laboratory to demonstrate recent improvements in long-term durability of SOECs. Electrolyte-supported and electrode-supported SOEC stacks were provided by Ceramatec Inc., Materials and Systems Research Inc. (MSRI), and Saint Gobain Advanced Materials (St. Gobain), respectively for these tests. Long-term durability tests were generally operated for a duration of 1000 hours or more. Stack tests based on technologies developed at Ceramatec and MSRI have shown significant improvement in durability in the electrolysis mode. Long-term degradation rates of 3.2%/khr and 4.6%/khr were observed for MSRI and Ceramatec stacks, respectively. One recent Ceramatec stack even showed negative degradation (performance improvement) over 1900 hours of operation. A three-cell short stack provided by St. Gobain, however, showed rapid degradation in the electrolysis mode. Optimizations of electrode materials, interconnect coatings, and electrolyte-electrode interface microstructures contribute to better durability of SOEC stacks.
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Sahak, Muhammad Zakwan Mohd, Siti Nur Amira Shaffee, Maung Maung Myo Thant, Faris Akmal Aminuddin, Devina Rawat, Patricia Alejandra Fleitas Calzadilla, Ram Kumar Krishnan, and Nabil Saiffudin. "Advancement in Green Hydrogen Production: Integrating Solid Oxide Electrolysis Cells (SOECs) into Existing Offshore Facilities for Sustainable Energy." In APOGCE 2024. SPE, 2024. http://dx.doi.org/10.2118/221154-ms.
Повний текст джерелаАнотація:
Abstract Hydrogen energy has been hailed as a versatile energy of the future that could aid the transition to net-zero emissions. It has large potential as an alternate fuel source for mobility and power, heating and feedstock for the industry. The energy carrier is produced from water electrolysis technology using different types of electrolyzer (i.e., Proton Exchange Membrane (PEM) or Solid Oxide Electrolysis Cells (SOECs)) for hydrogen separation process. In this energy research journey, PETRONAS has jointly worked with SLB to evaluate the feasibility of using SOECs for green hydrogen production. The study's focus is to explore integrating SOECs into existing industrial facilities creating hybrid systems, specifically with available flue gas from combustion process e.g. power generation. This allows for the utilization of waste heat from existing processes to enhance overall energy efficiency in hydrogen production. To understand hydrogen production and its utilization in the existing facility, the full system including existing gas turbines, solid oxide electrolyzer cells (SOECs), a hydrogen compression train, and a temperate cooling water system were modeled in a process simulation software. The model also included a heat recovery steam generator (HRSG) to recover the energy from gas turbine exhaust gases to heat water feed to produce saturated steam which will be the feed to SOEC. Several configurations considering heat integrations were explored, including heat recovery from SOEC product stream. Various sensitivities were run for different configurations of the process to study hydrogen purity, hydrogen blending, overall power required, water required in the overall process, and power produced by the hydrogen generated from SOEC and CO2 emission values in all the configuration. The results were compared and evaluated to help assess how variation in parameters affect the performance or outcome. The results were evaluated for blending the produced hydrogen with the existing export gas before and after export gas compression and how it influences the hydrogen purity. Hydrogen blending with the fuel gas to the gas turbine also helped in overall reduction of CO2 emission. It was observed that additional cooling of the hydrogen stream to achieve better hydrogen purity did not significantly help in reducing CO2 emissions when hydrogen is used as fuel gas; therefore, cooling with temperate water system can be considered. All the cases were compared and evaluated for expanding the application of green hydrogen technologies in the facility considering viability and reduction in emissions. The study was a part of a collaborative research initiative by the industry players to accelerate the development and deployment of SOEC technologies in existing facilities. The results from the study provided an overall understanding of adding SOEC in the facility and valuable insights to the stakeholders to make well-informed choices on the configuration.
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Kang, Juhyun, Joonguen Park, and Joongmyeon Bae. "3-Dimensional Numerical Analysis of Solid Oxide Electrolysis Cells (SOEC) Steam Electrolysis Operation for Hydrogen Production." In ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2014 8th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fuelcell2014-6368.
Повний текст джерелаАнотація:
Hydrogen is a resource that provides energy and forms water only after reacting with oxygen. Because there are no emissions such as greenhouse gases when hydrogen is converted to produce energy, it is considered one of the most important energy resources for addressing the problems of global warming and air pollution. Additionally, hydrogen can be useful for constructing “smart grid” infrastructure because electrical energy from other renewable energy sources can be stored in the form of chemical energy by electrolyzing water, creating hydrogen. Among the many hydrogen generation systems, solid oxide electrolysis cells (SOECs) have attracted considerable attention as advanced water electrolysis systems because of their high energy conversion efficiency and low use of electrical energy. To find the relationship between operating conditions and the performance of SOECs, research has been conducted both experimentally, using actual SOEC cells, and numerically, using computational fluid dynamics (CFD). In this investigation, we developed a 3-D simulation model to analyze the relationship between the operating conditions and the overall behavior of SOECs due to different contributions to the over-potential. All SOECs involve the transfer of mass, momentum, species, and energy, and these properties are correlated. Furthermore, all of these properties have a direct influence on the concentration of the gases in the electrodes, the pressure, the temperature and the current density. Therefore, the conservation equations for mass, momentum, species, and energy should be included in the simulation model to calculate all terms in the transfer of mass, heat and fluid. In this simulation model, the transient term was neglected because the steady state was assumed. All governing equations were calculated using Star-CD (CD Adapco, U.S). The source terms in the governing equations were calculated with in-house code, i.e., user defined functions (UDF), written in FORTRAN 77, and these were linked to the Star-CD solver to calculate the transfer processes. Simulations were performed with various cathode inlet gas compositions, anode inlet gas compositions, cathode thickness, and electrode porosity to identify the main parameters related to performance.
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Nelson, George, and Comas Haynes. "Parametric Studies of Constriction Resistance Effects Upon Solid Oxide Cell Transport Phenomena." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15100.
Повний текст джерелаАнотація:
The competition between mass transfer and electronic resistance effects arising from solid oxide cell interconnect geometry has been initially explored through parametric studies based on a design of experiments (DOE) approach. These studies have demonstrated the advantages of smaller interconnect-fuel stream total width and the increased dominance of mass transport as a limiting factor at low fuel stream hydrogen compositions. In addition to the direct effects of solid oxide fuel cell (SOFC) interconnect geometry on mass and electronic transport phenomena, the compounded effects of fuel stream concentration and cell current loading are considered. Finally, the parametric studies conducted for SOFC operation have been applied to the operation of solid oxide electrolysis cells (SOECs). These additional studies have demonstrated that interconnect designs that benefit SOFC performance are mutually beneficial for SOEC performance.
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Gao, Wenxiu, Xiongbin Liu, Zhende Zhou, and Xiaowei Li. "A Preliminary Thermodynamic Model of Hydrogen Generation Using Solid Oxide Electrolysis Cell (SOEC) Coupled With a High-Temperature Gas-Cooled Reactor." In 2024 31st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2024. http://dx.doi.org/10.1115/icone31-135353.
Повний текст джерелаАнотація:
Abstract To pave the way for industrial-scale hydrogen production using the high-temperature gas-cooled reactor (HTGR), it is necessary to assess the technical feasibility of various hydrogen production processes coupled with a HTGR. In this paper, several promising hydrogen production methods were compared from the perspectives of technological maturity, economic viability, and coupling efficiency with HTGR plants. Among these methods, the solid oxide electrolysis cell (SOEC) hydrogen production technology was considered the most promising approach due to its high efficiency and ease of industrial-scale production. A preliminary thermodynamic model was established for the HTGR-SOEC co-generation plant based on the parameters of a typical HTGR with a full power of 250 MWe and a steam temperature of 540 °C. The normal operating current and voltage of the SOECs coupled with HTGR were chosen as 1 A and 1.287 v, respectively, and SOEC modules were stacked together in the thermodynamic model to achieve the final hydrogen output. Key parameters that influence the hydrogen production rate and efficiency were simulated and discussed in detail using the thermodynamic model. Current research has deepened the study of carbon-free hydrogen production technology using nuclear energy and provided useful insights for future hydrogen-electricity co-generation applications.
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Zhang, Xiaoyu, James E. O’Brien, and Robert C. O’Brien. "Recent Advances in High Temperature Electrolysis at Idaho National Laboratory: Single Cell Tests." In ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2012 6th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fuelcell2012-91048.
Повний текст джерелаАнотація:
An experimental investigation on the performance and durability of single solid oxide electrolysis cells (SOECs) is under way at the Idaho National Laboratory. In order to understand and mitigate the degradation issues in high temperature electrolysis, single SOECs with different configurations from several manufacturers have been evaluated for initial performance and long-term durability. A new test apparatus has been developed for single cell and small stack tests from different vendors. Single cells from Ceramatec Inc. show improved durability compared to our previous stack tests. Single cells from Materials and Systems Research Inc. (MSRI) demonstrate low degradation both in fuel cell and electrolysis modes. Single cells from Saint Gobain Advanced Materials (St. Gobain) show stable performance in fuel cell mode, but rapid degradation in the electrolysis mode. Electrolyte-electrode delamination is found to have significant impact on degradation in some cases. Enhanced bonding between electrolyte and electrode and modification of the microstructure help to mitigate degradation. Polarization scans and AC impedance measurements are performed during the tests to characterize the cell performance and degradation.
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Kim-Lohsoontorn, P., H. B. Yim, and J. M. Bae. "Electrochemical Performance of Ni-YSZ, Ni/Ru-GDC, LSM-YSZ, LSCF and LSF Electrodes for Solid Oxide Electrolysis Cells." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33017.
Повний текст джерелаАнотація:
The electrochemical performance of solid oxide electrolysis cells (SOECs) having nickel – yttria stabilized zirconia (Ni-YSZ) hydrogen electrode and a composite lanthanum strontium manganite – YSZ (La0.8Sr0.2MnO3−δ – YSZ) oxygen electrodes has been studied over a range of operating conditions temperature (700 to 900°C). Increasing temperature significantly increased electrochemical performance and hydrogen generation efficiency. Durability studies of the cell in electrolysis mode were made over 200 h periods (0.1 A/cm2, 800°C, and H2O/H2 = 70/30). The cell significantly degraded over the time (2.5 mV/h). Overpotentials of various SOEC electrodes were evaluated. Ni-YSZ as a hydrogen electrode exhibited higher activity in SOFC mode than SOEC mode while Ni/Ru-GDC presented symmetrical behavior between fuel cell and electrolysis mode and gave lower losses when compared to the Ni-YSZ electrode. All the oxygen electrodes gave higher activity for the cathodic reaction than the anodic reaction. Among the oxygen electrodes in this study, LSM-YSZ exhibited nearest to symmetrical behavior between cathodic and anodic reaction. Durability studies of the electrodes in electrolysis mode were made over 20–70 h periods. Performance degradations of the oxygen electrodes were observed (3.4, 12.6 and 17.6 mV/h for LSM-YSZ, LSCF and LSF, respectively). The Ni-YSZ hydrogen electrode exhibited rather stable performance while the performance of Ni/Ru-GDC decreased (3.4 mV/h) over the time. This was likely a result of the reduction of ceria component at high operating voltage.
Звіти організацій з теми "SOECs"
1
Luo, Zheyu, Xueyu Hu, Doyeub Kim, Nikhil Govindarajan, and Meilin Liu. Durable and High-Performance SOECs Based on Proton Conductors for Hydrogen Production. Office of Scientific and Technical Information (OSTI), September 2024. http://dx.doi.org/10.2172/2446773.
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2
Wagner, Rodrigo. Mechanism for Market Valuation of State-Owned Enterprises without Privatization. Inter-American Development Bank, July 2017. http://dx.doi.org/10.18235/0007032.
Повний текст джерелаАнотація:
State-owned enterprises (SOEs), including state-owned banks, can be both systemically and politically important for many economies. While many of these firms have been privatized in recent decades, for various political or practical reasons many are likely to remain 100 percent state-owned, which prevents them from obtaining a market-based valuation. Having a market signal for the value of SOEs could be desirable because it could help: (i) inform the treasury of the net present value (NPV) of expected cash flows; (ii) impose some discipline on management; (iii) signal changes in capture by entrenched groups; and (iv) value discoveries and R&D that are slow to show up in cash flows. This paper presents a novel mechanism to create a market value for SOEs that cannot have publicly traded equity. It is based on the idea that parties, potentially independent from the SOE, can trade contingent financial claims for the future cash flows that an SOE pays to the government. Technically, it is a set of Arrow-Debreu securities that can mimic the SOE’s cash flows. The document discusses various ways to implement this principle, as well as the potential challenges and some answers to these challenges. Preliminary calculations show that issuing claims equivalent to 5 to 10 percent of salient Latin American SOEs could be sizeable to get analyst coverage and liquidity, without compromising state ownership of assets and decisions.
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Doshi, R., J. Routbort, and M. Krumpelt. Characterization of ceria-based SOFCs. Office of Scientific and Technical Information (OSTI), December 1996. http://dx.doi.org/10.2172/460187.
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Coelho, Daphne, Thomaz Teodorovicz, André Martínez Fritscher, Renata Motta Café, Sergio G. Lazzarini, and Jorge Norio Rezende Ikawa. Monitoring the Governance of State-Owned Enterprises: Assessing the Impact of Brazilian Corporate Governance Reforms. Inter-American Development Bank, May 2024. http://dx.doi.org/10.18235/0012994.
Повний текст джерелаАнотація:
State-owned enterprises (SOEs) are often justified for correcting market failures, providing essential public services, and fulfilling social objectives. Yet, SOEs face unique governance challenges as agency conflicts usually increase with state ownership. This paper examines Brazil's efforts to address agency conflicts in SOEs, including new legislation (Law 13303 of 2016, the “Law on SOEs”) establishing stringent criteria for the appointment of executives and for the accountability and a complementary monitoring mechanism known as IG-SEST. Using the difference-in-differences methodology, we assess the impact of those interventions on SOEs profitability and labor productivity. Although no significant effect of the more-stringent governance requirements of the Law on SOEs was detected, the group of federal SOEs, which adopted the IG-SEST monitoring mechanism, significantly increased their profitability compared to similar municipal and state SOEs. Because IG-SEST anchored its indicators in corporate governance parameters specified in the Law on SOEs, this result can be interpreted as potential evidence that institutional changes might require complementary mechanisms for effective implementation. These findings are consistent with previous work suggesting that corporate governance might require broader institutional reforms, including fiscal policies to mitigate government action with a negative effect on the performance and solvency of SOEs.
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Cochran, Joe, Jim Lee, Meilin Liu, Dave McDowell, and Tom Sanders. Hybrid Metal/Electrolyte Monolithic Low Temperature SOFCs. Fort Belvoir, VA: Defense Technical Information Center, October 2004. http://dx.doi.org/10.21236/ada427529.
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Miyake, Yasuo, Yukinori Akiyama, and Takashi Yasuo. Development status of planar SOFCs at Sanyo. Office of Scientific and Technical Information (OSTI), December 1996. http://dx.doi.org/10.2172/460158.
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Moreno de Acevedo Sánchez, Enrique. State-owned Enterprise Management: Advantages of Centralized Models. Inter-American Development Bank, May 2016. http://dx.doi.org/10.18235/0007966.
Повний текст джерелаАнотація:
This document analyzes the advantages and disadvantages of the different management models of state-owned enterprises (SOEs) in Latin America and the Caribbean. SOEs are important in the region. In many countries, they provide basic services to citizens, and their economic importance is relevant in terms of public finance. At the same time, SOEs confront political, financial, regulatory, and managerial problems, making them less efficient and transparent. In turn, governments should adopt management models to minimize these problems, while helping to ensure the quality of services and avoid the associated fiscal risks. This document argues that centralized models offer more advantages in correcting the current deficiencies of SOEs.
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Jamieson, Matthew. Solid Oxide Fuel Cell (SOEC) operations. Office of Scientific and Technical Information (OSTI), January 2023. http://dx.doi.org/10.2172/1922944.
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Reyes-Tagle, Gerardo, Roger Hosein, Aldo Musacchio, Rodrigo Wagner, Carolina Pan, Fernando Yu, Rebeca Gookool, et al. Smoldering Embers: Do State-Owned Enterprises Threaten Fiscal Stability in the Caribbean? Edited by Gerardo Reyes-Tagle, Aldo Musacchio, Carolina Pan, and Yery Park. Inter-American Development Bank, February 2022. http://dx.doi.org/10.18235/0004001.
Повний текст джерелаАнотація:
This book examines the role of state-owned enterprises (SOEs) in contributing to the fiscal instability of the Bahamas, Barbados, Guyana, Jamaica, Suriname, and Trinidad and Tobago (CCB6), with the aim of providing tangible guidance for policymakers seeking to address this issue. Using an original dataset of SOE performance in the Caribbean, the contributors focus on the fiscal implications of unchecked growth, poor oversight, and mismanagement of SOEs, with particular focus on commercial SOEs. The authors examine the historical, economic, and socio-political context of SOEs in the CCB6 and stress the need for simultaneous fiscal reform both at the federal and firm levels. The authors analyze the SOE sectors growth and performance to date, revealing entrenched challenges, specifically around incentives and accountability. The recommendations propose adaptations of accepted international best practices and lay out long-term objectives and the more feasible points of entry for fiscal reform.
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Rambabu Bobba. Dense Membranes for Anode Supported all Perovskite IT-SOFCs. Office of Scientific and Technical Information (OSTI), September 2006. http://dx.doi.org/10.2172/902844.
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