The Ni/YSZ composite electrode is conventionally used for solid oxide cells, in electrolysis (SOEC) as well as fuel cell (SOFC) operation. For enhanced electrochemical performance at low temperature, mechanical durability, and impurity tolerance, alternative fuel electrode materials and cell configurations are required. In this paper we have studied a metal supported cell (MSC) with a titanate-based fuel electrode (La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3, LSFNT) for its fuel cell performance using carbon containing fuel and compared to a state of the art (SoA) fuel electrode supported cell with a Ni/YSZ fuel electrode. In hydrogen fuel, the cells showed similar performance at intermediate and low temperatures (750 to 650°C), although the ASR is slightly higher for the MSC at all temperatures and steam/hydrogen ratios. Additionally, the MSC showed fair initial performance in reformate type fuel compositions (CO/steam and CO/steam/hydrogen), i.e. the fuel electrode possesses activity for the water gas shift reaction, which opens the possibility to use such cells with hydrocarbon fuels after a pre-reformer. Durability testing in pre-reformed fuel gas revealed that further fuel electrode tailoring is required to minimize cell degradation in carbon containing fuels.

The Ni/YSZ composite electrode is conventionally used for solid oxide cells, in electrolysis (SOEC) as well as fuel cell (SOFC) operation. For enhanced durability and C-tolerance, alternative fuel electrode materials are needed. In this paper, we compare the performance of two distinct Ni:CGO electrocatalyst coated A-site deficient lanthanum doped strontium titanate (La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3, LSFNT) based anodes, integrated into metal supported cells (MSCs), to the SoA Ni/YSZ anode supported cell in fuel cell mode for the first time. The three cells were investigated electrochemically by impedance spectroscopy (EIS) and performance under applied current (iV-curves) at temperatures 750˚C, 700˚C, 650˚C, and at novel 620˚C in steam/hydrogen and methane/steam. Additionally, one of the MSCs was investigated in CO/steam. Furthermore, galvanostatic durability tests were conducted in 4% steam/hydrogen for the MS-cells at low temperature (650˚C) at medium-high fuel utilization (50%).

In a time, where first solid oxide based systems enter demonstration and commercial markets, the European NewSOC project focuses on next generations. It aims at significantly improving performance, durability, and cost competitiveness of solid oxide cells and stacks compared to state-of-the-art (SoA). In order to achieve these goals, NewSOC investigates twelve innovative concepts in the following areas: (i) structural optimization and innovative architectures based on SoA materials, (ii) alternative materials, which allow for overcoming inherent challenges of SoA, (iii) innovative manufacturing to reduce critical raw materials and reduction of environmental footprint at improved performance and lifetime. The NewSOC unifies competences of 16 strong research and industry players. First scientific highlights were achieved despite the challenging working conditions under the European wide Covid-19 restrictions in the first year of the project. The presentation will provide a selection of these highlights.

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Solid oxide technologies (SOC: Solid oxide fuel cells SOFC & Solid oxide electrolysis SOE) are key enabling technologies for energy systems based on renewable sources and allow for a strong interlinking of sectors electricity, heat, and gas/fuels. SOC can emerge as key players in many concepts, such as fuel/gas to power and heat at small to large scale, energy storage through power to hydrogen/fuel, utilization and upgrading of biogas, balancing of intermittent electricity from renewable sources through load following and reversible operation, and central and decentral solutions for electricity and heat production. In a time, where first SOC systems enter demonstration and commercial markets, the NewSOC project focusses on next generations. It aims at significantly improving performance, durability, and cost competitiveness of solid oxide cells & stacks compared to state-of-the-art (SoA). In order to achieve these goals, NewSOC investigates twelve innovative concepts in the following areas: (i) structural optimization and innovative architectures based on SoA materials, (ii) alternative materials, which allow for overcoming inherent challenges of SoA, (iii) innovative manufacturing to reduce critical raw materials and reduction of environmental footprint at improved performance & lifetime. The NewSOC unifies competences of 16 strong research and industry players. First scientific highlights were achieved despite the challenging working conditions under the European wide covid-19 restrictions in the first year of the project. The presentation will provide a selection of these highlights. One focus area is the development of novel electrode materials, where high performance, impurity tolerance and stability are the primary targets. Nanostructured fuel electrodes based on doped SrTiO3 perovskites such as LaSrFeNiTiO3 are being developed as backbones. Subsequent, wet infiltration of Ni:GDC ensures high electro catalytic activity and ionic conductivity, while retaining the advantages of Ni-metal free fuel electrodes outlined above. Furthermore, a class of doped lanthanum chromites (La0.75Sr0.25CrxM1-xO3-δ, M=Fe, Mn, Ni) is developed as Ni-metal free fuel electrodes, to overcome the challenges faced by the SoA Ni-cermets. The perovskite structured electrodes, combined with highly conductive electrolytes have high performance, low ASR and flexibility in various operating modes (SOEC, rSOC). The most attractive feature of this class of electro catalysts is that they retain their properties (oxidative state, conductivity) in reducing and oxidizing environments at SOC operating temperatures, even in absence of a reducing agent, i.e. H2. Another approach is to modify SoA electrodes. Commercial (SoA) Ni/GDC was modified with iron by deposition – precipitation (D.P.), leading to enhanced performance as functional SOE fuel electrode. The promoting effect depends on the wt.% Fe content, where D.P. of quite a small amount of iron, through the formation of a Ni-Fe alloy, caused a 3-fold enhancement compared to Ni/GDC. Interestingly, the 0.5-Fe-Ni/GDC electrode performed similarly well like the noble-metal modified 3Au-0.3Mo-Ni/GDC. Materials compositions and structuring go hand in hand for tailoring cell properties. Under this focus, novel air electrode architectures for SOFC & SOE applications based on Co- and Ni-free materials with the (La, Ca, Sr)FeO3 perovskite class of materials are developed. The typically increased overpotential of Co- and Ni-free air electrodes is a challenge, which is tackled by introduction of a patterned porous barrier layer and addition of a composite layer at the electrode/electrolyte interface to enhance the triple phase boundary density between electrolyte and the Co-free air electrode. In another approach, the microstructure of SoA Ni/YSZ and LSCF/GDC electrodes was assessed to identify the best tradeoff between the cell performances, the durability and the robustness by a methodology coupling of manufacturing, characterization, and modeling. As a result, the performance of the LSCF/GDC composite electrode was improved, with different porosities, graded electrodes and composites. The role of the Ni/YSZ microstructure on the Ni migration during operation was investigated, with focus on finer and more homogeneous electrodes. Manufacturing and deposition methods contribute significantly to performance & lifetime, but also costs and environmental impact of SOC production. Thus, alternative approaches providing cells & stacks with required specifications are part of the NewSOC project. Progress on sputter deposited GDC buffer layers has been obtained in view of their implementation in the fabrication process of commercial Solid Oxide Fuel Cells.

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Danmarks Radios og Ole Bornedals stort anlagte tv-serie »1864« delte vandene i 2014. Lad det være sagt straks, at følgende er min helt personlige og stærkt subjektive vurdering af den. Jeg er skuffet og ærgerlig, og jeg mener, at serien i bund og grund ikke handler om Krigen 1864 og dens langvarige og vidtrækkende følger. Det er ikke sårfeberen fra 1864, vi bliver klogere på, men sårfeberen fra 2001. Det lyder sikkert kryptisk – og lidt indebrændt, og det må faktisk gerne læses sådan. For jeg er dybt provokeret af tv-serien, så er også det sagt.

Solid oxide cells (SOCs) are a key enabling technology for the required future renewable energy systems by providing an efficient link between the power, gas, and heat sectors. Specifically, solid oxide fuel cells (SOFCs) convert the chemical energy of a fuel into electricity and heat with high electrical efficiencies. Hydrogen is the obvious choice of fuel due to the only emissions being steam, however hydrocarbon fuels are an interesting and safe alternative to hydrogen, especially for mobile applications, facilitating easy integration into existing infrastructure. The state-of-the-art (SoA) Ni:YSZ (yttria-stabilized zirconia) composite fuel electrode is capable of direct oxidation of hydrocarbons or of reforming of hydrocarbon gas mixtures. Unfortunately, the material that facilitates the above reactions, nickel, is also an excellent carbon deposition catalyst. This is problematic, due to the associated volumetric changes and reduction in electrochemically active sites. Ultimately, the fuel electrode can delaminate from the electrolyte, causing a catastrophic failure of the cell. Alternative fuel electrode materials are the key to avoid this. A-site deficient lanthanum doped strontium titanate (La0.4Sr0.4Fe0.03Ni0.03Ti0.94O3, LSFNT) based anodes, coated with Ni:CGO (gadolinium-doped ceria) electrocatalyst are a promising alternative - while avoiding Ni as a major part of the backbone, the infiltrated Ni ensures electrocatalytic activity. The co-infiltrated CGO serves to improve the ionic conductivity. Integrating these anodes into a metal supported (MS) design ensures lower cost and mechanical robustness. Full cells are manufactured through scalable tape casting and screen printing technology, including the metal support. Possible pitfalls for the MS-cell include vulnerability to corrosion of the metal support and decreased reforming activity due to less electrocatalyst (Ni) compared to the SoA-cell. In this study, the reforming activity of methane in 3 different SOFCs is investigated: Cell 1 is with a SoA Ni:YSZ anode, cell 2 is with a LSFNT anode and cell 3 is with a LSFNT-FeCr anode. The investigation involves electrochemical characterization by impedance spectroscopy (EIS) and performance under applied current (I/V-curves) at temperatures 750˚C, 700˚C, 650˚C and 620˚C, so-called fingerprints, with special emphasis on the anode activity for reforming and water gas shift reaction. Furthermore, galvanostatic durability tests are conducted for the MS-cells (cell 2 and cell 3) with focus on the durability at low temperature (650˚C) and corrosion resistance at medium to high fuel utilization (ca. 50%). The degradation of the tested cells is examined by comparing the electrochemical performance before and after durability testing.