bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexible and Modular Fully Metallic Housing Concept for Solid Oxide Fuel Cells
Authors: Steinrücken Benjamin , Herrmann Stephan , Hauck Maximilian , Spliethoff Hartmut 
Published: July 2021

The state-of-the-art alumina oxide housings used in single cell test rigs are fragile, inflexible and expensive. They are designed for a specific cell geometry, a change of the cell type - changing the cell thickness - or a change in the cell size is not intended and is thus associated with an immense expenditure of effort and time. In detail, the state-of-the-art ceramic frame concept is vulnerable to a fracturing of the frame or an insufficient contacting of the cell if a change in the cell thickness occurs. The connection of the ceramic housing with the typically metallic tubing of the gas supply is fragile, prone to develop leakages and is time consuming to replace and thereby prevents a change of the cell size. Gold wire seals used at the cathode side are a common source of leakage. Furthermore, the whole ceramic housing is sensitive to fracturing due thermal or load induced stress, and thus prevents fast thermal cycling of the specimen.
This paper presents a modular, fully metallic housing concept which enables a fast and easy change of the cell size due to the utilization of a baseplate and a robustness towards different cell thicknesses due to the usage of a flexible metallic frame. The utilization of metal instead of alumina oxide reduces the manufacturing costs. Furthermore, an additional sealing on the cathode side enables a separation of the contacting pressure via a pneumatic piston from the sealing pressure applied via metallic screws. The force of the sealing pressure is not applied onto the cell and is thereby limited by the material constraints and not by the mechanical stability of the cell. For accurate voltage measurements, sense wires are separated from the current collection and are electrically isolated from the metallic housing. Thermocouples are used to measure the temperature distribution inside the anodic part of the housing, as close as possible to the cell. The chromium evaporation of the cathode part of the housing is reduced by a protective coating and the utilization of double layered tubes. In the end, the results of preliminary tests are presented.
Design and 3D Printing of Controllable and Gradient Porous Supports for Solid Oxide Fuel Cells
Authors: Du Yanhai , Panthi Dhruba , Sahu Sulata , Feng Hai , Baker Patrick 
Published: July 2021

A controllable and gradient porous structure is desirable for many applications including solid oxide fuel cells (SOFC) electrodes. A SOFC contains a minimum three basic ceramic thin films with a thin yet dense electrolyte layer separates the adjacent porous anode and cathode layers. In general, the thinner the electrolyte layer, the smaller the ohmic resistance would be. The anode and cathode layers need to be porous so to allow gases (e.g. H2 and O2) to easily penetrate to the triple-phase boundary (TPB). At the same time the anode and cathode layers serve as the paths of removing the electrons generated at the TPBs. Properly design and fabricated porous electrode microstructure could greatly increase the connectedness of gas, electrons and/or protons/oxygen ions, and therefore reduce the gas diffusion and ohmic resistances of the SOFC electrodes and boost the overall fuel cell performance.
Although there are electrolyte- and cathode- supported SOFC developers, the most used configuration is anode-supported or additional component-supported, for example metal-supported or ceramic-supported with a planar or tubular geometry. Conventionally, the porosity is generated by using sacrificial templates or pyrolyzable pore-formers for pore formation. Pores are formed after the burning off these sacrificial templates or pyrolyzable pore-formers at elevated temperatures. The size, shape and amount of the pore-formers can be controlled. However, the connectivity and orientation of these pores are not easily controllable, leaving significant amount of closed and isolated pores. These isolated and/or closed pores do not contribute to the TBP. Freeze casting of water-based suspension slurries could generate aligned pores, the low connectivity and weak mechanical strength challenges remain.
This paper focuses on the design and fabrication of a desired gradient porous microstructure for use as a SOFC support. The pore size and shape, porosity and connectivity could be determined and strictly controlled by design. Tubular and planar parts with metal, cermet and/or ceramic materials are to be fabricated. Additive manufacturing (AM, or 3D printing) process enables the fabrication of the complicated parts with the desired microstructure directly from the computer-aided design (CAD) models. The morphology, porosity, permeability and tortuosity of the 3D printed parts are investigated and results are discussed.
Progress of SOC Development at Elcogen
Authors: Noponen Matti , Torri Pauli , Göös Jukka , Puranen Jouni , Lehtinen Timo , Pylypko Sergii , Ounpuu Enn 
Published: July 2021

Elcogen is one of the leading European manufacturers of solid oxide cell (SOC) technology. Elcogen products are unique combination of best in class performance and low-cost product structure. The unit cell and stack products are designed for low temperature operation enabling major cost reductions in the system level. Elcogen’s operations are located in the Nordic-Baltic technology cluster of Finland and Estonia. This article summarizes the recent activities and development trends of Elcogen.
Elcogen is currently focused in ramping up its unit cell and stack production with the increased customer needs. The short-term goal is to set-up of a demonstration manufacturing plant for the unit cells and stacks with annual capacity of 50 MW. To facilitate the goals Elcogen has signed EUR 12 million loan facility with The European Investment Bank (EIB). The loan is the first in the Baltic countries to get support under the InnovFin – EU-finance for innovators programme, which is financed from the EU’s Horizon 2020 research and innovation programme. Specifically, the financing falls under InnovFin’s Energy Demonstration Projects (EDP) facility.
Elcogen is continuously developing its products for higher performance, longer lifetime, lower costs, increased quality and expanded applications. As an example, Elcogen has been testing its stack efficiency and lifetime for methane-based gas applications. The maximum efficiency has exceeded 75 % efficiency. The degradation rate in 23 000 hours test has been 15 mOhm.cm2/1000h.
Development of Solid Oxide Electrolysis and Reversible Solid Oxide Cell and Stack Technologies at Nexceris, LLC
Authors: Dogdibegovic Emir , Arkenberg Gene , Kopechek David , Wallace Anila , Swartz Scott 
Published: July 2021

Increasing demand for long-term energy storage, reduced carbon emissions, more resilient grid, and the lowest cost grid balancing solutions promotes solid oxide electrolysis cell (SOEC) and reversible solid oxide cell (RSOC) technologies. These systems can achieve high hydrogen production rates with near 100 percent stack electrical efficiency while co-electrolysis of carbon dioxide and water leads to production of syngas. RSOC can serve as a grid storage device (hydrogen production) and power production plant (provide electricity during peak demand). With over 25 years’ experience building and testing solid oxide cell materials, components and stacks, Nexceris has a proven track-record of commercializing products to major OEMs. The established manufacturing platforms at Nexceris enable smooth expansion into new applications.
In this talk, development of cells, stack components and stacks will be discussed. Performance and durability improvements from single cell to short stacks will be addressed. Cells with downselected electrode sets were implemented into short stacks with active cell area of 42 cm2 and 96 cm2. Stacks were operated continuously in SOEC mode at ~1.3 V for ≥ 500 hours with <5%/kh degradation and improving. The resulting short stack demonstrations show promising baseline performance and durability platform for future cell and stack development. RSOC tests were recently initiated with dynamic operation. Nexceris’ ChromLok coatings for bipolar plates were also integrated to stacks to enhance durability.
Progress in SOC Development at Fraunhofer IKTS
Authors: Kusnezoff Mihails , Jahn Matthias , Megel Stefan , Reichelt Erik , Trofimenko Nikolai , Herz Gregor , Beckert Weiland , Schilm Jochen , Rost Axel , Schoene Jakob , Wagner Doerte , Ganzer Gregor , Sauchuk Viktar , Nousch Laura , Hielscher Sebastian , Hartmann Mathias , Rothe Stefan , Michaelis Alexander 
Published: July 2021

Despite long and successful development history of Solid Oxide Cells (SOC) continuous improvement in performance, longevity, manufacturing and system integration is necessary to bring this highly efficient technology to the market. The activities on material development and optimization at IKTS are focused mainly on enhancement of durability in SOFC, SOEC and rSOC operation and on boosting the power density for electrolysis operation. The recent results show considerable enhancement in cell longevity and power density.
The SOC priorities in applied research are moving from materials to industrialization and Fraunhofer as applied R&D service provider is following this trend. During recent years considerable efforts on simplification and automation of cell and stack manufacturing processes has been addressed at IKTS. The manufacturing processes for electrode manufacturing have been adjusted for high yield automated printing on thin electrolytes with integrated quality control measures. The efficient ways for reduction of time and energy consumption for sealing process of SOC stacks have been found and shown in pilot production as well as automated assembling of components to stacks demonstrated. Furthermore the stack integration into modules utilizing stacks of different providers has been addressed during last years and reliable solutions for building of compact stack modules of higher power (2 to 10 kW) has been developed and tested with industrial partners.
The increasing interest in “green hydrogen” generated multiple opportunities for SOEC technology to be considered as inherent part of industrial and chemical processes. IKTS pioneering work on coupled operation of SOEC module with Fischer-Tropsch reactor provided first demonstration of feasibility of this approach for waxes production. The process design and analysis of steel, using SOEC technology, has been performed and resulted in multiple demonstration activities in last four years. Recently novel approaches for ammonia production are addressed at IKTS showing opportunity for transportable chemicals/fuel production without need of CO2 source.
High power electrolysis applications (>10 MW) will need new approaches for stack design and put higher requirements on durability. High power electrolysis applications will also open a new window of opportunities for industrial SOFC power plants. This vision is considered as outline for our future research.
Fabrication and Characterization of a Tubular Solid Oxide Fuel Cell with Impregnated Perovskite Electrodes
Authors: Nowicki Kamil Maciej , Wang Mei , Irvine John Thomas Sirr 
Published: July 2021

Thanks to large efficiency and ability to work in both fuel cell and electrolysis mode Solid Oxide Cells (SOCs) could become a vital technology in the transition to the carbon-neutral energy sector based on hydrogen. However, large cost and low durability constrain their full-scale commercialization. These challenges are tackled in the present work. Tubular cells are produced by a simple and inexpensive method, suitable for mass production. The cells showed excellent activity, stability and redox resistance due to tubular design and fully ceramic electrodes. Thermal shock resistance testing showed that the cell is resistant to rapid temperature changes.
A thick supporting layer of the porous backbone was cast first, and a thin layer of electrolyte over it. After rolling into a tubular shape, the assembly was co-sintered and impregnated with functional perovskite materials. Co-casting allowed to achieve a strong interface and reduce the thickness of electrolyte. The impregnation gave the possibility to deposit a perovskite in temperature much lower than in state-of-art methods, preventing the undesirable reaction with zirconia electrolyte and reducing their densification, producing more active spatial microstructures with large surface area. Moreover, such electrodes are more thermally compatible with electrolyte as their bulk TEC is mainly controlled by the porous backbone made of the same material as the electrolyte.
Yttria-stabilized zirconia (Zr0.92Y0.16O2.08, 8YSZ) is used as the electrolyte, for the fuel electrode nickel doped lanthanum calcium titanate (La0.43Ca0.37Ni0.06Ti0.94O3-
γ, LCNT) was impregnated onto a porous 8YSZ backbone, while on the air electrode a lanthanum strontium ferrite (La0.8Sr0.2FeO3, LSF) was applied. These materials offer high activity and stability for a relatively low price. Electrochemical impedance spectroscopy (EIS), current-voltage (I-V) and potentiostatic measurements were carried out to characterize cell performance and cell’s stability during the test. The electrochemical testing showed improvement in the cell performances after electrochemical poling at high potential, due to facilitated LCNT reduction and exsolution of nickel nanoparticles.
The cheap fabrication method, competitive performance, attracting redox stability and thermal shock resistance, braking the major limitation for SOFC applicability, making it even suitable to be used in portable applications.
The “Innovation Liquid Energy” (ger. “Innovation Flüssige Energie” - IFE) Project: Development of a 1MW Power-to-Liquid Plant Based on Co-SOC Electrolysis and Fischer-Tropsch Synthesis
Authors: Hauth Martin , Reiter Bernd 
Published: July 2021

The European climate protection program adopted in 2018 targets for a reduction in greenhouse gas emissions from the current 20% to 40% (compared to 1990) by 2030 ([1]), together with a simultaneous increase in the share of energy from renewable sources from the current 20% to 32%. In the transport sector, an increase in the share of renewable fuels from the current 10% to 14% is aimed for, with a maximum of 7% of this being Generation 1 fuels. Therefore, additional solutions such as power-to-liquid (PtL) fuels are needed to generate an immediate impact on existing fleets in order to achieve European and global CO2 emission targets in mobility.
The overall objective of the IFE (Innovation Liquid Energy) project is the development and realization of a Power-to-Liquid plant with a combined water and carbon dioxide high-temperature electrolysis (Co-SOEC) and a Fischer Tropsch synthesis for the production of synthetic fuel. By coupling these two processes in a way which enables heat integration, an increase of the overall electrical efficiency to 55% is to be achieved. The overall plant with a nominal electrolyser power of around 1 MW will constitute of several parts. Carbon dioxide is extracted from industrial waste gas or from a biogas/biomass plant and fed into the electrolyser process. There, a synthesis gas of hydrogen and carbon monoxide is produced based on an innovative Co-SOEC unit with an efficiency higher than 80%. In the next process stage, the syngas is fed into a low-temperature Fischer-Tropsch synthesis, where syncrude is produced with predominantly liquid and paraffinic products. The estimated output of Fischer-Tropsch products is around 500.000 L diesel-equivalent. The diesel fraction is targeted to meet the required quality of the EN15940 standard for alternative paraffinic diesel fuel.
The present work shows the status of the project and how specific challenges such as the reuse of the tail gas, the reuse of the aqueous product fraction and heat integration are addressed. Thereby a focus on the development of the co-SOEC unit and the optimization of the overall process towards highest efficiencies is being laid. Furthermore a techno-economic view on the potential cost of Fischer-Tropsch products is given, where, dependent on the electricity cost and full-load operating hours of the plant, FT-diesel costs in the range of 1-3 € seem reasonable (without tax and margin).
[1] The European parliament and the council of the European Union:DIRECTIVE (EU) 2018/2001, (L 328/82), Brüssel, 2018
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32018L2001&from=EN
Effect of Microstructure of the Anode Support Tubes Towards SOFC Performance
Authors: Sahu Sulata , Panthi Dhruba , Feng Hai , Du Yanhai 
Published: July 2021

Reversible solid-oxide fuel cells (rSOFC) attract enormous attentions because of their capability to operate in both fuel cell and electrolysis modes. rSOFC with a tubular cell design has multiple advantages over a planar design for example allowing faster startup and shutdown. Successful fabrication of tubular cells needs to overcome numerous technological challenges, including control of its mechanical stress and high interlayer electrode resistance. The scope of the present work involves fabrication and testing of anode supported rSOFC single cells using both ionic conducting electrolyte and protonic conducting electrolyte. For the ionic conducting cells, the rSOFCs constituted Ni + yttria-stabilized zirconia (YSZ) anode support tube, Ni + scandia-stabilized zirconia (ScSZ) anode functional layer, scandia-stabilized zirconia (ScSZ) electrolyte, samarium doped ceria (SDC) protective layer, La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) + SDC cathode functional layer, and LSCF cathode current collector layer, respectively. For the protonic conducting cells, BaZr0.1Ce0.7Y0.1Yb0.1O3-d (BZCYb) was used as electrolyte.
In this work, sequential dip-coating coupled with co-firing technique was implemented over the thin film cell structure fabrication. The nickel based tubular anode supports were made from various methods, including extrusion, freeze-casting and dipping processes. To achieve low interlayer resistance and dense electrolyte layer, we have optimized the ceramic slurry (ink) formulation parameters. Cell performance and microstructure of the rSOFC will be discussed and compared with the available data.
Importance of Mixed-Conducting Materials for High-Temperature Fuel Cells Applications
Authors: Fung Kuan-Zong , Chang Ting-You , Tang Jhih Yu , Tsai Shu-Yi 
Published: July 2021

In many electrochemical devices, mixed ionic/electronic conduction have received great attention. For instance, oxygen transport membrane (OTM) based on (Ba,Sr)(Co,Fe)O3 perovskite exhibit unique hole/oxygen ion mixed conduction behavior for oxygen separation application.
Accordingly, electrodes/electrolytes exhibiting both electronic and/or multiple ionic conducting properties have been used for high temperature fuel cell application. For example, mixed conducting electrodes based on composite electrode (e.g. LSM/SDC, LSM/YSZ) show improved SOFC performance in comparison to conventional electrode. Such unique conduction behavior may be rationalized based on defect chemistry consideration. Thus, the materials processing and microstructure design may become key issues to optimize their mixed conduction properties. For instance, better hole and oxygen conducing perovskite may be obtained when desired aliovalent dopant and oxidizing atmosphere are used.
Thus, the objective of this work is to conduct (1) fabrication/design of MIEC through defect-favored processing, (2) microstructure development for better gas transport, (3) characterization of conduction/interfacial kinetics for better electrodes/electrolytes performance. Desired analytical equipment such as SEM, XRD, electrochemical impedance spectroscopy (EIS) and cell testing are performed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrode/electrolytes will be discussed based on defect chemistry consideration and individual microstructure and morphology including pore size, pore distribution and interface area.
Inkjet 3D Printing of Functional Layers of Solid Oxide Fuel Cells (SOFCs) and Electrolyzers (SOEs)
Authors: Kawale Shrikant , Jang Inyoung , Alexander John , Kelsall Geoff 
Published: July 2021

Hydrogen production using renewable energy sources could enable the technological objectives to be met of decarbonising electrical power generation, energy storage to mitigate renewable energy intermittency and balancing electrical power supply and demand. The required reactors and processes need to be efficient, economic, durable, and of scalable design and fabrication. Additive manufacturing, e.g. by inkjet printing of ceramic particles offers novel means of fabricating solid oxide fuel cells and electrolysers with reproducible geometries, predictable densities of triple phase boundaries, and upscaling of electrode | electrolyte interfacial areas using imaginative 3D structures, thereby decreasing specific costs.
We shall present results of using 3D inkjet printing, currently with ca. 10 mm lateral resolution, followed by sintering, for fabrication of SOFCs and SOEs. Having characterised their particle size distributions, zeta potentials and rheologies, colloidal dispersions of < ca. 200 nm yttria-stabilised zirconia (8-YSZ), NiO and lanthanum strontium manganite (LSM) particles were formulated. Having optimised inkjet printing parameters, these dispersions were used for printing 3D structures using a Ceradrop X-Serie piezoelectric DOD printer with a DIMATIX Sapphire QS-256/30 AAA printhead with 52 µm nozzle diameters. Gas-tight planar YSZ electrolyte layers were printed and sintered with ca. 10 mm thicknesses, onto porous Ni(O)-YSZ substrates. Porous LSM electrode layers also were printed on pressed YSZ substrates; cracking of printed layers due to capillary forces were mitigated by avoiding attractive depletion potentials and judicious control of sintering conditions. Detailed optimization of printing parameters, droplet size and substrate temperatures will be presented for electrolyte and electrode layers.