SOC stack comprising combined flow distributor and contact enabler

Abstract

A solid oxide cell stack has a combined flow distributor and contact enabler made of a pressed metal foil with diversion structures and contact regions between interconnect layers and cell layers in the stack.

Description

Technical Field

[0001] The present invention relates to a solid oxide cell (SOC) stack, in particular a solid oxide electrolysis cell (SOEC) stack or a solid oxide fuel cell (SOFC) stack, comprising a plurality of elements, each of which is a combined flow distributor and contact enabler. Background Art

[0002] The present invention can be used in general in SOC stacks - thus in both SOEC and SOFC modes, even though for simplicity some parts of the following description refer to the SOEC mode.

[0003] In an SOC stack having an operating temperature between 600°C and 1000°C, preferably between 600°C and 850°C, several battery cells are assembled to form a stack and connected together by interconnects. The interconnects act as a gas barrier to separate the anode and cathode sides of adjacent battery cells, and at the same time they enable conduction of current between adjacent cells, i.e. between the anode of one cell and the cathode of an adjacent cell. Further, the interconnects typically provide multiple flow paths for the passage of process gases on both sides of the interconnect. To optimize the performance of the SOC stack, a range of positive values should be maximized without unacceptable consequences for another range of related negative values that should be minimized. Some of these values are:

[0004]

[0005] Almost all of the values listed above are interdependent, meaning that changing one value will affect the others. Some relationships between the characteristics of the process gas flow in the cell and the above values are mentioned here:

[0006] Process gas utilization:

[0007] The flow paths on the interconnects should be designed to seek to get equal amounts of process gas to each cell in the stack, ie there should be no flow "shortcuts" through the stack.

[0008] Parasitic losses:

[0009] The design of the process gas flow paths in the SOC stack and its cells should seek to achieve low pressure losses per flow volume, which will reduce parasitic losses in the blowers.

[0010] Electrical efficiency:

[0011] The interconnect directs current between the anode and cathode layers of adjacent cells. Therefore, to reduce internal resistance, the conductive contact points of the interconnect (hereinafter simply referred to as "contact points") should be designed to establish good electrical contact with the electrodes (anode and cathode), and the contact points should not be too far apart, which would force the current to travel a longer distance through the electrodes and result in higher internal resistance.

[0012] life:

[0013] It is desirable to maximize the life of the SOC stack, i.e., in SOFC mode, it can be used to generate as much electricity as possible, and in SOEC mode, to maximize the amount of electrolysis products (e.g., H and / or CO). Stack life depends on many factors, including the choice of interconnects and spacers, flow distribution on the two process gas sides of the interconnect, uniform distribution of protective coatings on the materials, operating conditions (temperature, current density, voltage, etc.), cell design and materials, edge reoxidation that reduces life, and many other factors.

[0014] cost:

[0015] The cost contribution of interconnects (and spacers) can be reduced by not using expensive materials, by reducing production time of interconnects and spacers, minimizing the number of components, and by minimizing material loss (the amount of material discarded during the production process).

[0016] size:

[0017] The overall size of the fuel stack is reduced when the interconnect design ensures high utilization of the active cell area. Dead zones with low process gas flow should be reduced and inactive areas for sealing surfaces should be minimized.

[0018] Production time.

[0019] The production time of the interconnects and spacers themselves should be minimized, and the interconnect design should also facilitate rapid assembly of the entire stack. Generally speaking, for each component that eliminates the need for an interconnect design, there is a gain in production time.

[0020] Failure rate.

[0021] The production methods and materials of interconnects and spacers should allow for low interconnect failure rates (e.g., unwanted holes in the interconnect gas barrier, uneven material thickness or properties). Furthermore, when interconnect designs reduce the total number of components to be assembled and reduce the length and number of sealing surfaces, the failure rate of assembled cell stacks can be reduced.

[0022] Number of components.

[0023] In addition to minimizing malfunctions and assembly times, as already mentioned, the reduction in the number of components also leads to reduced costs.

[0024] Anode and cathode gas flows are distributed within the SOC stack by providing a common manifold for each of the two process gases. The manifold can be internal or external. The manifold supplies process gases to individual layers within the SOC stack via channels to each layer. The channels are typically located within a layer of the repeating elements included in the SOC stack, either within the spacers or within the interconnects.

[0025] Interconnects and spacers made from sheet metal are typically made from two separate pieces of sheet material that are sealed together in the SOC stack. This requires a seal between the interconnect and spacer, as well as handling of the separate components during production. Furthermore, because the two separate pieces of sheet material often have the same outer dimensions, a lot of material is wasted when most of the center material of the spacer is removed (e.g., punched out).

[0026] Solid oxide electrolysis cells (SOECs) can be used to convert HO into H, CO into CO, or a combination of HO and CO into synthesis gas (H and CO). This conversion occurs on the cathode side (fuel side) of the SOEC, where the cell contains a nickel-containing layer in its reduced state. On the oxygen side (anode) of the SOEC, oxygen gas is produced and typically flushed with air.

[0027] When solid oxide cells are stacked into a SOC stack, the cells are separated by interconnects that have several functionalities. The functionality of the interconnects includes 1) separating the gases between the fuel and oxygen sides of the SOC, i.e. the fuel side containing the fuel of H2O and / or CO2 and the oxygen side of the SOC containing the oxygen stream of air and O2. 2) distributing the flow of the two gases (fuel or oxygen stream) on their respective sides of the active area of the SOC. 3) transmitting the electrical current from one cell in the stack to the next - from the fuel side of one cell to the oxygen side of the adjacent cell. 4) enabling sufficient electrical contact between the cell and the interconnects on both sides. 5) mechanically supporting the SOC and 6) ensuring all of the above requirements while taking into account the production tolerances of all components in the stack (cells, sealing materials and the interconnects themselves), i.e. the thickness and straightness tolerances of the components.

[0028] Thus, interconnects have many functionalities, some of which oppose each other and all of which interact to a large extent, which complicates the design and limits design freedom. It would therefore be an advantage if some of the interconnect functionality could be separated from other components to reduce the complexity of the interconnect design, thereby resulting in greater freedom in design and production, as well as in material selection.

[0029] Contact enablers are often used between the IC and the battery to ensure good contact and, to some extent, absorb minor production tolerances. Especially on the fuel side of the battery interconnect, a thin (<100 μm) mesh, foam, or other material made of nickel or other materials is often used to ensure good electrical contact by providing a (slightly) deformable element between the nickel-containing battery layer and the interconnect. The nickel mesh or foam can ensure good electrical contact on the fuel side by accommodating some local or minor production tolerances.

[0030] Thus, using a contact enabler on the fuel side can be used to mitigate functionality 4) and, to a lesser extent, 6) of the interconnect functionalities listed above. For example, using nickel contact enable elements on the fuel side is a good way to ensure good electrical contact because the nickel contact enabler can bond to the nickel-containing fuel-side cell layers through interdiffusion between the contact element and the cell. Similarly, the nickel contact enabler can be bonded to the interconnect, which is typically made of high-temperature ferritic stainless steel.

[0031] The present invention aims to solve the problem of moving more functionality from the interconnect to the fuel-side contact enable element by including contact enablement, flow distribution, and absorption of production tolerances in the contact enable element. Thus, the functionality of the interconnect can be reduced to 1) gas separator, 2) flow distributor - only on the oxygen side, 3) current conductor between cells, 4) contact enabler - only on the oxygen side, and 5) cell support - only on the oxygen side.

[0032] US6492053 discloses a fuel cell stack including an interconnect and a spacer. Both the interconnect and the spacer have inlet and outlet manifolds for oxygen / fuel flow. The inlet and outlet manifolds have grooves / channels on their surfaces for distributing oxygen / fuel along the anode and cathode. However, the grooves / channels of the interconnect and spacer are not aligned with each other, and therefore their geometries cannot be combined to achieve multiple entry points. Furthermore, because the grooves / channels are on the surfaces of both the interconnect and the spacer, forming multiple entry points is not feasible.

[0033] US2010297535 discloses a bipolar plate for a fuel cell having flow channels. The flow plate has multiple channels for evenly distributing fluid between the active areas of the fuel cell. The document does not describe a second layer and similar channels within it.

[0034] US2005016729 discloses a ceramic fuel cell supported in a thermally conductive interconnect plate, with multiple plates forming a conductive heater called a stack. Multiple stacks are connected to form a fuel cell rod. By connecting multiple stacks end to end, a fuel cell string is formed. The length of the string can be 1,000 feet or more, sized to penetrate underground resource layers (such as oil layers). A preheater brings the string to an operating temperature exceeding 700°C, and the fuel cell then maintains this temperature via multiple conduits that supply fuel cell fuel and oxidant and transfer exhaust gases to a planetary surface. A manifold can be used between the string and the planetary surface to extend the multiple conduits and act as a heat exchanger between the exhaust gas and the oxidant / fuel.

[0035] None of the known techniques described above provides a simple, effective solution to the above described problems.

[0036] Therefore, with reference to the considerations listed above, there is a need for a solution for producing a SOC stack comprising a combined flow distributor and contact enabler that is simple and easy, yet still robust, efficient and accurate.

[0037] These and other objects are achieved by the invention as described below. Summary of the Invention

[0038] As mentioned above, the standard solution is an interconnect with at least 6 functionalities, which can be slightly reduced by introducing contact enablers, which are typically used between the fuel side of the interconnect and the cell to ensure good contact and to some extent absorb small / local production tolerances (roughness).

[0039] In one embodiment, the present invention is a new type of contact enabler, for example on the fuel side of the stack between the cells and the interconnect, in the form of a deep drawn (pressed) nickel foil (or other material) that is much thicker (~500μm) than standard solutions of nickel mesh or foam (<100μm).

[0040] The thickness of the deep drawn nickel foil is sufficient to accommodate the fuel distribution channels, thus ensuring flow distribution to the active area of the fuel side of the cell. As a standard solution, the deep drawn nickel foil will also ensure sufficient electrical contact between the cells and the interconnects, but because the foil is deformable during stack production and can be pressed to a greater height than the finished geometry in the stack (+~100μm) – the nickel foil can also absorb all production tolerances from all components when the stack is produced, eliminating this functional requirement from the interconnects.

[0041] Several interconnect functionalities are transferred to a novel deep-drawn nickel contact-enabling foil. This reduces the interconnect's complexity, resulting in greater design freedom for the interconnect. The interconnect lacks fuel-side functionality because the nickel foil handles flow distribution and contacting, allowing the interconnect design, material selection, and fabrication methods to be optimized for the oxygen side of the cell (and as a gas separator).

[0042] The nickel foil is a more complex component than standard contact-enabling nickel mesh or foam, but because the nickel foil only experiences fuel-side conditions, it only needs to be optimized for fuel-side conditions with respect to flow distribution and contact. Therefore, the additional functionality of the contact-enabling element (nickel foil) is achieved at a marginal additional cost to the component.

[0043] In one embodiment, a major advantage of the novel contact and flow distribution element of deep drawn nickel foil is its ability to absorb all production tolerances of all components used to build the stack (cells, sealing materials, interconnects and the nickel foil itself). This is achieved by deep drawing the nickel foil to a height that is greater than its final height in the stack - it is produced at an "overheight". The overheight of the nickel foil serves to accommodate the (even large) production tolerances of the stack components while ensuring that there is adequate contact and support for the cells on the fuel side when the stack is produced and the stack components are compressed together. The nickel foil can be designed to creep during the production process of the stack because deep drawing can produce a "creep-able" structure. Furthermore, the fact that the nickel foil on the fuel side is in a reducing environment compared to the interconnects and cells ensures a high creep ratio for the nickel.

[0044] The ability to absorb large production tolerances of stack components reduces the requirements on components and production methods, thereby reducing costs.

[0045] In one embodiment, using nickel foil as the contact enable element between the fuel side cells and the interconnect has the same contact enable benefits as standard contact enablers made of nickel mesh or foam in that they can form a strong bond with the cells and interconnect. However, using a new, higher nickel foil as the contact enabler introduces a more flexible element to ensure contact between the cells and the interconnect during operation, where thermal expansion can disrupt contact. Because the nickel foil bonds well to the cells and interconnect and is able to creep thereon, contact integrity is maintained during operation even with large thermal expansion differences between layers (the nickel foil acts as a bonding string between the cells and the IC, allowing for variations in distance between the cells and the interconnect due to thermal expansion differences of the components and temperature gradients in the stack).

[0046] The invention according to claim 1 is a solid oxide cell stack comprising a plurality of stacked cell units as known in the art. Each cell unit comprises a cell layer comprising solid oxide cells and an interconnection layer comprising interconnects. As is known, the interconnection layer separates one cell layer from an adjacent cell layer in the cell stack. The particularity of the present invention is that the cell units in the stack also comprise at least one combined flow distributor and contact enabler made of pressed metal foil. This has the function of providing a flow pattern for the process gas in a desired pattern and amount and providing a clear, strong and reliable mechanical and electrical contact between the interconnect and the adjacent cell layers between which the combined flow distributor and contact enabler are located.

[0047] In one embodiment of the invention, the combined flow distributor and contact enabler is specifically located on the fuel side of the interconnect, which fuel side again faces the fuel side of the adjacent solid oxide cell in the solid oxide cell stack. The flow guides and contact areas of the combined flow distributor and contact enabler can have specified dimensions, which is possible because the combined flow distributor and contact enabler are made of pressed metal foil rather than, for example, a contact enabler made of a more undefined mesh. The metal foil can have protrusions that are pressed to a precisely specified dimension (the thickness of the combined flow distributor and contact enabler) or even a precisely specified oversize, and then pressed to its final dimension when the stack is assembled and compression forces are applied. Similarly, the flow guides and contact areas of the combined flow distributor and contact enabler can be positioned at a specified distance from each other and in a specified pattern, which is again possible because they are made of metal foil pressed according to a specified pattern or mold rather than, for example, a metal mesh whose appearance and structure may be more chaotic or unstable.

[0048] In one embodiment of the present invention, each combined flow distributor and contact enabler has a contact area, i.e., the area of the combined flow distributor and contact enabler that is in physical and mechanical contact with the adjacent solid oxide cell, which occupies between 2% and 50% of the total area of the adjacent solid oxide cell. The combined flow-guiding structure and contact area can be formed as elongated, wavy protrusions pressed into the metal foil, and they can be positioned and oriented to provide alternating flow paths. In one embodiment, the combined flow-guiding structure and contact area are formed as elongated, straight, and wavy protrusions pressed into the metal foil, wherein each protrusion contacts the metal foil only on one side of the wave. In another embodiment, the wavy protrusions can be curved.

[0049] In one embodiment, the metal foil can be pressed without removing material from the foil, while in another embodiment, material can be removed from the metal foil, and in another embodiment, the removed material can provide guides for the pressing of the metal foil. Further, areas with material removed from the metal foil can provide flow paths through the combined flow distributor and contact enabler. Before the metal foil is pressed, it can be laser cut, etched, water jet cut (or micro-abrasive water jet cut), or stamped, whichever process best suits the purpose of producing the combined flow distributor and contact enabler. The production process of the combined flow distributor and contact enabler can also involve pressing and cutting the metal foil at the same time.

[0050] In one embodiment of the present invention, as also described and explained above, the metal foil is made of nickel or at least coated with nickel. The thickness of the metal foil used to produce the combined flow distributor and contact enabler can be between 50 μm and 1200 μm, preferably between 100 μm and 300 μm. After the metal foil of the combined flow distributor and contact enabler is pressed, the height of the combined flow distributor and contact enabler is between 200 μm and 3000 μm, preferably between 400 μm and 1000 μm. Therefore, due to the pressed protrusions in the metal foil, the height of the combined flow distributor and contact enabler after it is pressed is greater than the thickness of the metal foil itself.

[0051] As also described above, the combined flow distributor and contact enabler can be produced to an "over" thickness prior to assembly in a solid oxide cell stack. Thus, the height of the combined flow distributor and contact enabler prior to assembly between the interconnect and the solid oxide cell is between 20 μm and 1000 μm, preferably between 50 μm and 200 μm, greater than the height of the combined flow distributor and contact enabler when located within the solid oxide cell stack after production of the finished solid oxide cell stack. Thus, after production of the solid oxide cell stack, which may involve pressing forces and elevated temperatures, the height of the combined flow distributor and contact enabler is reduced while providing good mechanical and electrical contact between the interconnect and adjacent cells.

[0052] Thus, in one embodiment of the invention, the combined flow distributor and contact enabler is connected to the solid oxide cell by diffusion bonding on at least a portion of the surface of the combined flow distributor and contact enabler facing the solid oxide cell.

[0053] In one embodiment of the present invention, a well-defined orientation and position of the combined flow distributor and contact enabler relative to at least its adjacent interconnect is fixed by at least one fixed guide structure adapted to interact with the interconnect to provide a specific position of the combined flow distributor and contact enabler relative to the interconnect. The fixed guide structure may be made of a bent part, at least partially stamped and bent parts of the combined flow distributor and contact enabler, or materials positioned by spot welding or laser welding.

[0054] In one embodiment of the present invention, at least a major portion of the surface of the interconnect facing the combined flow distributor and contact enabler is flat and free of protruding flow-guiding structures and contact areas. In another embodiment of the present invention, the solid oxide cell stack is a solid oxide electrolysis cell stack.

[0055] Features of the invention

[0056] 1. A solid oxide cell stack comprising a plurality of stacked cell units, each cell unit comprising a cell layer comprising solid oxide cells and an interconnect layer comprising interconnects, an interconnect layer separating one cell layer from an adjacent cell layer in the cell stack, wherein the cell unit further comprises at least one combined flow distributor and contact enabler made of pressed metal foil and comprising a combined flow guide structure and a contact area, the combined flow distributor and contact enabler being located between the interconnect layer and the cell layer and providing physical and electrical contact between the interconnect layer and the cell layer.

[0057] 2. A solid oxide cell stack according to feature 1, wherein the combined flow distributor and contact enabler is located on the fuel side of the interconnect, which fuel side faces the fuel side of an adjacent solid oxide cell in the solid oxide cell stack.

[0058] 3. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guiding structure and contact area have specified dimensions.

[0059] 4. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guiding structures and contact areas are positioned at specified distances and in a specified pattern.

[0060] 5. A solid oxide cell stack according to any one of the preceding features, wherein each of the combined flow distributors and contact enablers has a contact area with an adjacent solid oxide cell, the contact area being between 2% and 50% of the total area of the adjacent solid oxide cells.

[0061] 6. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow directing structures and contact areas are positioned in a pattern suitable for providing alternating flow paths.

[0062] 7. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guiding structures and contact areas are pressed, elongated and wavy protrusions in the metal foil.

[0063] 8. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guiding structures and contact areas are pressed, elongated, straight and wavy protrusions in the metal foil.

[0064] 9. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guide structure and contact area is a pressed, elongated, straight and wavy protrusion in the metal foil, wherein each protrusion contacts the metal foil only on one side of the wave.

[0065] 10. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow guiding structures and contact areas are pressed, elongated, curved and wavy protrusions in the metal foil.

[0066] 11. A solid oxide cell stack according to any one of the preceding features, wherein the pressed metal foil comprises areas of the metal foil from which metal foil material has been removed.

[0067] 12. A solid oxide cell stack according to feature 11, wherein the removed metal foil material provides a guide structure for pressing of the metal foil.

[0068] 13. A solid oxide cell stack according to feature 11 or 12, wherein the removed metal foil material provides a flow path through the combined flow distributor and contact enabler.

[0069] 14. A solid oxide cell stack according to any of the preceding features, wherein the metal foil is laser cut or etched or water jet cut and / or micro-abrasive water jet cut or punched prior to the pressing.

[0070] 15. A solid oxide cell stack according to any one of the preceding features, wherein the metal foil is pressed and cut simultaneously.

[0071] 16. A solid oxide cell stack according to any of the preceding features, wherein the metal foil is made of nickel.

[0072] 17. A solid oxide cell stack according to any one of the preceding features, wherein the metal foil is coated with nickel.

[0073] 18. Solid oxide cell stack according to any of the preceding features, wherein the metal foil has a thickness between 50 μm and 1200 μm, preferably between 100 μm and 300 μm.

[0074] 19. A solid oxide cell stack according to any one of the preceding features, wherein after the metal foil pressing of the combined flow distributor and contact enabler, the height of the combined flow distributor and contact enabler is between 200 μm and 3000 μm, preferably between 400 μm and 1000 μm.

[0075] 20. A solid oxide cell stack according to any one of the preceding features, wherein the height of the combined flow distributor and contact enabler before assembly between the interconnect and the solid oxide cell is between 20 μm and 1000 μm, preferably between 50 μm and 200 μm, greater than the height of the combined flow distributor and contact enabler when located in the solid oxide cell stack after production of the finished solid oxide cell stack.

[0076] 21. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow distributor and contact enabler is connected to the interconnect by diffusion bonding on at least a portion of the combined flow distributor and contact enabler surface facing the interconnect.

[0077] 22. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow distributor and contact enabler is connected to the solid oxide cell by diffusion bonding on at least a portion of the combined flow distributor and contact enabler surface facing the solid oxide cell.

[0078] 23. A solid oxide cell stack according to any one of the preceding features, wherein the combined flow distributor and contact enabler comprises at least one fixed guide structure adapted to interact with the interconnect to provide a specific position of the combined flow distributor and contact enabler relative to the interconnect.

[0079] 24. A solid oxide cell stack according to feature 23, wherein the at least one fixed guide structure is made of an at least partially stamped and bent part of a bent part, a combined flow distributor and a contact enabler, or a material positioned by spot welding or laser welding.

[0080] 25. A solid oxide cell stack according to any of the preceding features, wherein at least a major portion of the interconnect surface facing the combined flow distributor and contact enabler is flat and free of protruding flow-guiding structures and contact areas.

[0081] 26. A solid oxide cell stack according to any one of the preceding features, wherein the solid oxide cell stack is a solid oxide electrolysis cell stack.

Claims

1. A solid oxide cell stack comprising a plurality of stacked cell units, each cell unit comprising a cell layer comprising solid oxide cells and an interconnect layer comprising interconnects, an interconnect layer separating one cell layer from an adjacent cell layer in the cell stack, wherein the cell unit further comprises at least one combined flow distributor and contact enabler made of pressed metal foil and comprising a combined flow guide structure and a contact area, the combined flow distributor and contact enabler being located between the interconnect layer and the cell layer and providing physical and electrical contact between the interconnect layer and the cell layer.

2. The solid oxide cell stack of claim 1 , wherein the combined flow distributor and contact enabler is located on a fuel side of the interconnect that faces the fuel side of an adjacent solid oxide cell in the solid oxide cell stack.

3. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guiding structure and contact area have specified dimensions.

4. The solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guiding structures and contact areas are positioned at a specified distance and in a specified pattern.

5. A solid oxide cell stack according to any one of the preceding claims, wherein each of the combined flow distributors and contact enablers has a contact area with the adjacent solid oxide cell, the contact area accounting for between 2% and 50% of the total area of the adjacent solid oxide cell.

6. A solid oxide cell stack according to any preceding claim, wherein the combined flow guiding structures and contact areas are positioned in a pattern suitable for providing alternating flow paths.

7. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guiding structures and contact areas are pressed, elongated and wavy protrusions in the metal foil.

8. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guiding structures and contact areas are pressed, elongated, straight and wavy protrusions in the metal foil.

9. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guide structure and contact area is a pressed, elongated, straight and wavy protrusion in the metal foil, wherein each protrusion contacts the metal foil only on one side of the wave.

10. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow guiding structures and contact areas are pressed, elongated, curved and wavy protrusions in the metal foil.

11. A solid oxide cell stack according to any one of the preceding claims, wherein the pressed metal foil comprises areas of metal foil from which metal foil material has been removed.

12. The solid oxide cell stack of claim 11, wherein the removed metal foil material provides a guide structure for pressing of the metal foil.

13. The solid oxide cell stack of claim 11 or 12, wherein the removed metal foil material provides a flow path through the combined flow distributor and contact enabler.

14. A solid oxide cell stack according to any one of the preceding claims, wherein the metal foil is laser cut or etched or water jet cut and / or micro-abrasive water jet cut or punched prior to the pressing.

15. A solid oxide cell stack according to any preceding claim, wherein the metal foil is pressed and cut simultaneously.

16. A solid oxide cell stack according to any preceding claim, wherein the metal foil is made of nickel.

17. A solid oxide cell stack according to any preceding claim, wherein the metal foil is coated with nickel.

18. A solid oxide cell stack according to any one of the preceding claims, wherein the metal foil has a thickness between 50 μm and 1200 μm, preferably between 100 μm and 300 μm.

19. A solid oxide cell stack according to any one of the preceding claims, wherein after metal foil pressing of the combined flow distributor and contact enabler, the height of the combined flow distributor and contact enabler is between 200 μm and 3000 μm, preferably between 400 μm and 1000 μm.

20. A solid oxide cell stack according to any one of the preceding claims, wherein the height of the combined flow distributor and contact enabler before assembly between the interconnect and the solid oxide cell is between 20 μm and 1000 μm, preferably between 50 μm and 200 μm, greater than the height of the combined flow distributor and contact enabler when located within the solid oxide cell stack after production of the finished solid oxide cell stack.

21. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow distributor and contact enabler is connected to the interconnect by diffusion bonding on at least a portion of the surface of the combined flow distributor and contact enabler facing the interconnect.

22. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow distributor and contact enabler is connected to the solid oxide cell by diffusion bonding on at least a portion of the combined flow distributor and contact enabler surface facing the solid oxide cell.

23. A solid oxide cell stack according to any one of the preceding claims, wherein the combined flow distributor and contact enabler includes at least one fixed guide structure, which is suitable for interacting with the interconnect to provide a specific position of the combined flow distributor and contact enabler relative to the interconnect.

24. The solid oxide cell stack according to claim 23, wherein the at least one fixed guide structure is made of a bent part, an at least partially stamped and bent part of the combined flow distributor and contact enabler, or a material positioned by spot welding or laser welding.

25. A solid oxide cell stack according to any one of the preceding claims, wherein at least a major portion of the interconnect surface facing the combined flow distributor and contact enabler is flat and free of protruding flow guiding structures and contact areas.

26. A solid oxide cell stack according to any preceding claim, wherein the solid oxide cell stack is a solid oxide electrolysis cell stack.

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