Fuel cell and fuel cell stack

Abstract

A metal supported SOEC or SOFC fuel cell unit (10) includes a separator plate (12) and a metal support plate (14) having a chemical layer (50), the separator plate and the metal support plate overlapping each other to form a repeating unit, at least one plate having a flange peripheral feature (18) formed by pressing the plate, the plates directly connected at the flange peripheral feature to form a fluid volume (20) therebetween, each plate having at least one fluid port (22), wherein the ports are aligned and communicate with the fluid volume, and at least one plate having a pressed and formed molded port feature (24) extending around its port toward the other plate and including mutually spaced elements to define a fluid passageway to enable fluid to enter the fluid volume from the port. The protruding member (120) can receive a gasket (34) as a hard stop surface or as a seal bearing surface.

Description

[0001] The present invention relates to an improved electrochemical fuel cell unit and a cell stack comprising a plurality of such electrochemical fuel cell units, and methods for manufacturing the same. The present invention more particularly relates to metal-supported fuel cells, in particular metal-supported solid oxide fuel cell units of the oxidant type (MS-SOFC) or electrolyzer type (MS-SOEC), and their cell stacks.

[0002] Some fuel cell units can generate electricity by using an electrochemical conversion process (oxidizing the fuel). Some fuel cell units can also or alternatively operate as regenerative fuel cell (or reverse fuel cell) units, commonly known as solid oxide electrolyzer fuel cell units, for example, to separate hydrogen and oxygen from water, or to separate carbon monoxide and oxygen from carbon dioxide. They can have a tubular or planar configuration. Planar fuel cell units can overlap each other in a stacked manner, for example, 100-200 fuel cell units are a stack, and the individual fuel cell units are arranged in an electrical series manner.

[0003] Solid oxide fuel cells that generate electricity are based on solid oxide electrolytes that conduct negative oxygen ions from the cathode to the anode located on the opposite side of the electrolyte. To this end, the fuel or reformed fuel is in contact with the anode (fuel electrode) and the oxidant (such as air or oxygen-rich liquid) is in contact with the cathode (air electrode). Conventional ceramic-supported (such as anode-supported) SOFCs have low mechanical strength and are prone to breakage. Therefore, metal-supported SOFCs in which the active fuel cell component layers are supported on a metal substrate have recently been developed. In these cells, the ceramic layers can be very thin because they only perform electrochemical functions: that is, the ceramic layers are not self-supporting, but thin coatings / films that are laid on and supported by the metal substrate. Such metal-supported SOFC cell stacks are stronger, less expensive, have better thermal properties, and can be manufactured using conventional metal welding techniques than ceramic-supported SOFC cell stacks.

[0004] The applicant's earlier WO2015 / 136295 discloses a metal-supported SOFC, in which the electrochemically active layers (or active fuel cell element layers) include respective anode, electrolyte and cathode layers deposited (e.g., as thin coatings / films) on and supported by a metal support plate 110 (e.g., foil). The metal support plate has a porous region surrounded by a non-porous region, and the active layer is deposited on the porous region so that gas can pass through the holes from one side of the metal support plate to the other side to access the active layer coated thereon. Fig.42As shown, the fuel cell unit 90 includes three plates or layers - a metal support plate 110, a separator plate 150 and a spacer plate 152 sandwiched therebetween. It also has fluid ports 180, 200 (for oxidant or fuel), and the three plates are stacked on top of each other and welded (fused together) through the spacer plate 152 to form a single metal-supported solid oxide fuel cell unit, with the fluid volume in the middle defined by the large space 160 provided in the spacer plate 152. The metal parts of the repeated layers of the fuel cell stack are in electrical contact with each other, and the electron flow between them is mainly through the fusion / welding path, thereby avoiding surface-to-surface contact resistance losses.

[0005] As discussed in WO2015 / 136295, small holes (not shown) are provided on the metal support plate 110 through the metal support plate 110 at positions covering the anode (or cathode, depending on the polarity orientation of the electrochemically active layer), which is located below the metal support plate 110. They are located in the large space or small holes 160 defined by the spacer plate 152 to allow the fluid volume to be in fluid communication with the electrochemically active layer on the bottom surface of the support plate 110 through the small holes.

[0006] In the separator 150, the upper and lower corrugations 150A are configured to extend upward to the cathode (or anode, depending on the polarity direction of the electrochemically active layer) of the subsequent fuel cell unit stacked on the fuel cell unit, and extend downward to the metal support plate 110 of its own fuel cell unit. This achieves electrical connection between adjacent stacked fuel cell units, so that the stacked electrochemically active layers (usually one on each fuel cell unit) are connected in series.

[0007] A solid oxide electrolyser (SOEC) may have the same structure as a SOFC, but is essentially a SOFC operating in reverse or regenerative mode to electrolyze water and / or carbon dioxide using a solid oxide electrolyte to produce hydrogen and / or carbon monoxide and oxygen.

[0008] The present invention is directed to a stack of repeating solid oxide fuel cell units having a structure suitable for use as a SOEC or SOFC. For convenience, both SOEC or SOFC stacked cell units will be referred to as "fuel cell units" or simply "cells" (i.e., referring to SOEC or SOFC stacked cell units) hereinafter.

[0009] The present invention seeks to simplify the structure of the fuel cell unit because there is a continuous push to improve the cost-effectiveness of fuel cells - reducing their manufacturing costs will have a great benefit in reducing the entry cost of fuel cell energy production.

[0010] According to the present invention, there is provided a metal-supported solid oxide fuel cell unit, comprising:

[0011] Dividers; and

[0012] A metal support plate carrying a fuel cell chemical layer disposed on the porous region;

[0013] separator plates and metal support plates that overlap each other to form a repeating unit;

[0014] in:

[0015] At least one of the separator plate and the metal support plate includes a flange peripheral feature formed by pressing the plate into a concave configuration;

[0016] The separator plate and the metal support plate directly meet at the flange peripheral feature to form a fluid volume therebetween;

[0017] at least one fluid port is disposed within the flange perimeter feature of each of the separator plate and the metal support plate, the respective fluid ports being aligned and in communication with the fluid volume; and

[0018] At least one of the separator plate and the metal support plate has a molded port feature formed by pressing around its port and extending toward the other plate, and the elements of the molded port feature are spaced apart from each other to define a fluid passage from the port and located between the elements to enable fluid to pass from the port to the fluid volume.

[0019] In the present invention, instead of the three metal support plates, the spacer plates and the separator plates, only two of them (components) are needed, namely, the metal support plate and the separator plate, and the battery still operates in substantially the same manner, with the output of the electrochemically active layer per square centimeter per battery cell being substantially the same. In other words, there is no separate plate as a separator between them, and the battery cells still operate in the same manner. This simplifies the number of components that need to be supplied and handled (such as coating), and simplifies assembly, while also directly reducing the amount of material required, thereby reducing the material cost and weight of each fuel cell unit.

[0020] The recessed structure can give the associated plate the appearance of a rimmed tray, with a corresponding raised exterior shape (relative to the exterior of the fuel cell unit) and a generally planar base, whereby the recess defines a fluid volume within a (eg partially) assembled cell.

[0021] In this concave configuration, the flange peripheral feature extends from the plane of the original sheet material of the separator plate and / or the metal support plate toward the opposing surface of the other of the separator plate and the metal support plate.

[0022] Thus, the fluid volume is bounded by formed flange peripheral features formed by pressing, such as by using a die press, hydroforming or stamping. These are simple processes that have formed a central protrusion in the fluid volume, as found in prior art separator plates for supporting and electrically connecting adjacent fuel cells via electrochemically active layers.

[0023] These central protrusions include inlet and outlet protrusions (upper and lower protrusions as shown) extending between the opposing inner surfaces of the two plates and the outer surface of the electrochemically active layer of the battery cell adjacent to the outward protrusions. They also define a fluid passage between the two, or define an outward protrusion in the two (relative to the fuel cell cell), thereby defining a fluid passage through the fluid volume between the fluid ports at each end of the fuel cell cell.

[0024] In the present invention, the central inlet and outlet projections are therefore also pressed from the original sheet material of the separator plate, either before or after the flange peripheral features and the forming features, but more preferably at the same time.

[0025] In some embodiments, the central protrusion is circular. They can be other shapes, including elongated or corrugated similar to the prior art. They do not need to be in the exact center of the separator plate, although they can be distributed relative to the separator plate, but they will usually be between the inlet and outlet fluid ports of the fuel cell unit, so as to be centered relative to them.

[0026] Typically, at least two fluid ports are provided within the flange perimeter features of each of the separator plates and metal support plates, i.e. within the area enclosed by the flange perimeter features of these plates. These are typically inlet ports and outlet ports. There may be more than one inlet port and / or more than one outlet port. For example, a port may be provided at each corner of a plate.

[0027] In some embodiments, the porous region is formed by drilling holes, typically laser drilling, in the metal support plate.

[0028] In some embodiments, the (active) fuel cell chemical layer takes the form of an electrochemically active layer, the electrochemically active layer comprising an anode, an electrolyte and a cathode formed (e.g., coated or deposited) on a metal support plate and located above a porous region, in which embodiments, the porous region is disposed within the metal support plate. This arrangement in which the (non-self-supporting, thin) chemical layer is disposed directly on the metal support plate requires a minimum number of components. Thus, the metal support plate has the dual function of supporting the cell chemistry and limiting the fluid volume (together with the separator). Furthermore, it is understood that both the metal support plate and the separator plate have an oxidant exposed side and a fuel exposed side, and therefore, they are both components subject to the harsh dual atmospheric environment.

[0029] In other embodiments, the porous region is disposed on a separator plate (e.g., metal foil) on which the fuel cell chemical layers are formed (e.g., coated or deposited), and the separator plate (carrying the fuel cell chemical layers) is disposed on a window (e.g., frame) on a metal support plate.

[0030] There may be multiple regions of fuel cell chemistry layers. For example, there may be multiple regions of small holes on a metal support plate, with the small hole regions being covered by separate, respective electrochemically active layers. Alternatively, there may be multiple windows on a metal support plate, with active battery (fuel cell) chemistry layers formed above these windows on multiple separator plates.

[0031] The or each separator plate may be welded to the metal support plate on the window of the metal support plate.Thus, the central protrusion extending between the opposing inner surfaces of the two plates extends all the way to the inner surface of the separator plate.

[0032] In some embodiments, the shaped port features of the central region of the fuel cell and / or the inlet and outlet protrusions covering the electrochemically active layer have a substantially circular cross-section when bisected in the plane of the separator plate or metal support plate.

[0033] It is simple and low cost to form flange perimeter features, port features and any protrusions from a (e.g., initially flat) separator plate or metal support plate having an initial (substantially) uniform material thickness (i.e., over the entire extent of the plate) when performing the pressing step. In contrast, it is difficult, time consuming and wasteful of material to provide fluid flow volumes / channels or flange features by etching away material to form a plate with thicker and thinner areas.

[0034] In some embodiments, the fluid pathways from the fluid ports to the fluid volume are tortuous and / or intersect each other at multiple locations, such as by a staggered array of dimples or an arrangement of staggered elements.

[0035] In some embodiments, the shaped port features and inlet and outlet protrusions in the central portion of the fluid volume are dimples, preferably of circular cross-section as defined above.

[0036] The shaped port features define channels that form a portion of the fluid volume, so that the fluid channels extend from the ports, between the elements, to the open area, and further, the fluid channels extend through the "active area" of the cell (i.e., when in a stack) between the electrochemically active layers of adjacent fuel cells. In the open area, flow dividers may be provided to spread the fluid flow within the active area to the full width of the active area.

[0037] Preferably, the metal of the metallic support layer is steel (eg stainless steel) - a number of suitable ferritic steels (eg ferritic stainless steels) may be used.

[0038] Preferably, the separator plate is formed from a similar or same type of metal as the metal support layer.

[0039] In some embodiments, only the flange perimeter feature is provided on the separator plate. This simplifies production because the separator plate is already pressed in the central area and the metal support plate only needs to be cut into the required configuration.

[0040] In some embodiments, only the formed port features are provided on the separator plate. This also simplifies production because the separator plate is already pressed in the center area and only the metal support plate needs to be cut.

[0041] In some embodiments, the height of the shaped port features above the surface from which they extend is the same as the distance between the opposing inner surfaces of the two plates. Therefore, they extend to the inner plane of the opposing surface of the other plate. In this way, such features can be set on only one surface as a hard stop to transfer the compressive load around the port while maintaining the required fluid channel open. However, oppositely shaped port features can be set to extend from two surfaces toward each other to perform the same function adjacent to each other.

[0042] The use of sheet metal support plates and / or separator plates to press form flange perimeter features, molded port features, and inlet and outlet protrusions in the center region of the separator plate ensures that the structure for supporting the fluid volume height is formed from the same thin foil substrate as the rest of the metal support plate and / or separator plate, thereby keeping the weight of each battery cell low.

[0043] In some embodiments, at least one fluid port includes a fuel port, and thus the fluid volume in the fuel cell unit includes the fuel volume between the separator plate and the metal support plate.

[0044] In these embodiments, the fuel cell chemistry layers are typically formed on the outer surface of the metal support plate.

[0045] In some embodiments, the at least one fluid port comprises an oxygen-containing fluid port and the fluid volume comprises an oxygen-containing fluid volume between the separator plate and the metal support plate.

[0046] In these embodiments, the fuel cell component layers are typically disposed on the inner surface of the metal support plate.

[0047] In some embodiments, at least one of the separator plate and the metal support plate is provided with one or more protruding members formed by pressing, which extend from the other plate. Advantageously, these members may be arranged around each fluid port.

[0048] As described above, the molded port features (on at least one plate) can extend toward another (i.e., separator plate and metal support plate) plate of the corresponding fuel cell unit. By being arranged in the fluid volume between the two plates, they can be regarded as features arranged on the inner surface of the fuel cell unit. They maintain the internal spacing and transfer the load. On the other hand, the protruding members (on at least one plate) extend away from the other (same unit) plate (i.e., separator plate and metal support plate). For example, they can be arranged in a ring around the port and can therefore be regarded as features arranged on the outer surface of each fuel cell unit, which act between adjacent fuel cell units. Depending on their construction, arrangement and respective heights, they can perform positioning functions, hard stopper functions (maintaining spacing / transferring loads / limiting compression), fluid distribution functions and / or sealing support functions.

[0049] A plurality of protruding members may be arranged to define the space for accommodating the gasket in the protruding member and / or a plurality of protruding members, and / or a plurality of protruding members may be arranged to define the periphery of the gasket for accommodating the protruding member outside. When the fuel cell unit and the gasket are stacked alternately in a stacking manner to form a single repeated stacking unit of a fuel cell group, a large amount of time and energy may be spent on keeping each gasket in a proper position relative to the center of the port (e.g., using glue or tools). However, the protruding member can be used for lateral positioning of the gasket, even if it is centered around the port. Conveniently, the protruding member can define an internal space / area configured to accommodate the gasket in the protruding member, preferably closely matching the periphery of the gasket so as to receive and locate the space and shape of the gasket in the desired position, thereby avoiding positioning and fixing in place by other steps during assembly. In addition or alternatively, some protruding members may be arranged to define the outer periphery of the inner periphery (also with matching size and shape) of the gasket for accommodating the protruding member outside.

[0050] In some embodiments, a plurality of protruding members are interspersed between the molded port features.

[0051] Alternatively, the or each protruding member may be located outside the profiled port feature.Preferably, each protruding member is located radially beyond the profiled port feature relative to the centre of the port.

[0052] The or each protruding member may have a top end defining a hard stop surface against which adjacent fuel cell units or portions extending therefrom may abut during assembly of a stack of cells. Such a hard stop (surface) may maintain spacing between fuel cell units and assist in transferring compressive loads through the stack near the ports. There may be a plurality of protruding members defining hard stop surfaces, and the hard stop surfaces may all lie in the same plane.

[0053] The present invention also provides a fuel cell stack, comprising a plurality of such fuel cell units, the fuel cell units being stacked one upon the other, and having seals around the fluid ports between adjacent fuel cell units, the seals preferably covering the molded port features around the fluid ports between adjacent fuel cell units. The aligned fluid ports and seals thus form an internal oxidant or fuel manifold or "breathing channel" within the fuel cell stack, thereby preventing the oxidant from mixing with the fuel.

[0054] The seals may include gaskets. These may be preformed sealing devices, i.e., components such as rings or sheets of suitable shape for sealing between two surfaces. As described above, in a stacked arrangement, the fuel cell units and gaskets are stacked alternately with each other to form a single repeating unit of the stack, and the protruding members may be used to laterally position each gasket, i.e., center it around the port. When the protruding members are arranged to define a space for accommodating the gaskets, this assembly method may avoid the need for a gluing step or any other method of securing the gaskets.

[0055] Alternatively, the seal may include an in-situ seal (i.e., a non-self-supporting seal formed in situ), for example, formed by a sealing contact adhesive or liquid coated on one of the plates around the port, the sealing contact adhesive or liquid being bonded to the surface and cured in situ to provide a sealant around the port. The adhesive may be an elastic curable sealing paste. Advantageously, by replacing preformed gaskets with such seals, such stacking can only be assembled by stacking the fuel cell units directly on top of each other, which are the only components forming repeated stacking units.

[0056] The seal may be compressible. Preferably, it is an electrically insulating compressible seal. The stack needs to be assembled and compressed to ensure good airtightness and electrical contact in the active chemical layer area. Using a compressible seal around the ports helps to strengthen the airtightness in these areas of the stack without over-compressing the stack, which would damage the active chemical layer.

[0057] The seal may be electrically insulating. An electrically insulating seal may be used near the port to prevent short circuits between metal surfaces (which should not touch) of adjacent fuel surfaces. However, this may alternatively be achieved by coating at least one of the metal surfaces with an insulating layer or coating, such as by extending the electrolyte layer of the cell to cover the area around the port.

[0058] In some embodiments, the internal components of the fuel cell stack will only include repeated fuel cell units and seals covering molded port features around the fluid ports. The port features are formed by compression molding, and they define recessed holes covered by the seals on the outer surface of the plate from which they are formed, and these holes are optionally located on the protruding portions of the plate.

[0059] Each protruding member may have a top end defining a hard stop surface as described above, wherein the at least one seal on the seal receiving surface of the lower one of the fuel cell units has a height above the seal receiving surface before the next fuel cell unit is stacked thereon, and the hard stop surface of the lower one of the fuel cell units has a height above the seal receiving surface but below the seal located on the seal receiving surface to provide a limit to compression between adjacent fuel cell units. The use of such a hard stop surface with a seal ring can maintain a constant distance between adjacent fuel cell units, thereby mitigating irregularities or excessive compression of the in-situ seal or gasket over time.

[0060] In the case of a stacked arrangement where fuel cell units and gaskets are stacked alternately with each other to form a single repeating unit of the stack, providing a hard stop surface having a depth less than the depth of the non-compressed gasket (e.g., 75-95% thereof) is important for simplifying stack assembly and improving uniformity of the final stack height. In the assembly method, the stack can be compressed during the assembly process until the gasket is compressed, causing the hard stop surface to abut against the surface of the adjacent fuel cell unit and achieve a desired constant distance or spacing, and the load is transmitted through the hard stop structure.

[0061] In another variation of the fuel cell stack, in which the or each protruding member also has a top end defining the above-mentioned hard stop surface, at least one seal can abut against an upper seal receiving surface in an upper fuel cell unit, and before the upper fuel cell unit is stacked on the lower fuel cell unit, the seal has a second height that is higher than the lower seal receiving surface of the lower fuel cell unit, and the hard stop surface of the upper fuel cell unit has a height extending below the upper seal receiving surface that is less than the height of the seal seated on the lower seal receiving surface so as to provide a limit to compression between adjacent fuel cell units.

[0062] In some embodiments, at least one seal is partially located in a groove surrounding a corresponding fluid port of the seal, the groove being optionally located in a protruding portion of the plate. The groove preferably extends downwardly and into the space between the metal support plate and the separator plate of the fuel cell unit, and its depth does not exceed 50% of the distance between the metal support plate and the separator plate of the fuel cell unit.

[0063] The metal-supported solid oxide fuel cell unit or stack defined above can be arranged to generate heat and electricity from a supplied fuel and oxidant (such as air), i.e., a generative SOFC. Alternatively, it can be arranged for regeneration purposes, such as regenerating hydrogen from water, or regenerating carbon monoxide and oxygen from carbon dioxide, i.e., a regenerative SOEC.

[0064] The present invention also provides a method for manufacturing a fuel cell unit, which comprises the following steps.

[0065] Provide dividers;

[0066] providing a metal support plate; and

[0067] processing at least one of the metal support plate and the separator plate to form:

[0068] Flange peripheral features;

[0069] at least one fluid port in the separator plate and the metal support plate; and

[0070] forming at least one molded port feature around the at least one fluid port,

[0071] The processing includes at least pressing the plate or plates to form the flange perimeter feature, thereby forming a concave structure in the plate or plates, and likewise pressing the molded port feature;

[0072] The method further comprises:

[0073] stacking the separator plate and the metal support plate on each other to form a repeating unit;

[0074] The separator plate and the metal support plate are directly connected at the flange peripheral feature, wherein the flange peripheral feature forming the concave structure forms a fluid volume therebetween, wherein the molded port feature extends toward the other plate, and the elements of the molded port feature are spaced apart from each other to provide a fluid passage from the port to the fluid volume, and optionally, the fluid port is cut before pressing the plate or multiple plates.

[0075] A compressing step may be performed to compress adjacent fuel cell units into contact with each other.

[0076] If the seals are (prefabricated) gaskets, the method may include positioning them using only raised members, which are arranged and designed to receive and position the gaskets. In the case where a hard stop surface is provided, the method may involve compressing the stack until the hard stop surface contacts the surface of an adjacent fuel cell unit.

[0077] Before the electrochemically active layer components of the fuel cell chemistry support are applied to the metal support plate, the metal support plate is usually pressed.

[0078] The fuel cell unit or stack may be as previously described.

[0079] The present invention also provides a method for manufacturing a fuel cell stack using such a fuel cell unit, comprising: stacking such fuel cell units together, and using a seal (such as a gasket) between the two to cover the molded port features around the fluid ports between adjacent fuel cell units.

[0080] For the avoidance of any doubt, by pressing the plate to form the flange perimeter features, molded port features and inlet and outlet protrusions, there is no need to etch the plate to remove material from the sheet, nor are there molded port features deposited or printed on the surface to form integral features on a sheet having substantially different thicknesses.

[0081] In the disclosed embodiment, the porous region is provided by drilling holes (laser drilling) in a corresponding metal sheet (e.g., stainless steel (ferrite) foil). However, the porosity that allows fluid access to the active cell (e.g., fuel cell) chemistry may be provided in any suitable manner known in the art.

[0082] These and other features of the present invention will now be described in further detail by way of various embodiments and by way of example only, with reference to the accompanying drawings (which are not drawn to scale and in which the height dimensions are generally exaggerated for clarity), wherein:

[0083] Figure 1 shows a plan view of a fuel cell unit including a metal support of a first embodiment;

[0084] Figure 2 Shows Figure 1 A first perspective view of a fuel cell having two gaskets below the fuel cell;

[0085] Figure 3 yes Figure 2 a second perspective view of the arrangement shown from a different angle;

[0086] Figure 4 is with Figure 1 a plan view of an opposing fuel cell unit, with a gasket shown positioned over a fluid port of the fuel cell unit;

[0087] Figure 5 shows a cross-section through a fuel cell unit;

[0088] Figure 6 shows a cross-sectional view through a fuel cell unit and a gasket, showing the fuel cell unit as it is compressed during its assembly;

[0089] Figure 7 An exploded perspective view of a stack of two fuel cell units is shown with two gaskets underneath each fuel cell unit;

[0090] Figure 8 Shows Figure 7 A stack, but not shown in exploded form, of two battery cells stacked on top of each other with a first pair of gaskets between them and two further gaskets below the stack for stacking onto another fuel cell unit (not shown);

[0091] Fig. 9 An alternative fuel cell unit is shown in plan view, including a second embodiment, which is similar to the first fuel cell unit, but with the addition of a flange peripheral feature on the visible portion of the metal support plate of the fuel cell unit (around its fluid ports), rather than just around the fluid ports on the separator plate of the fuel cell unit.

[0092] Fig.10 is a perspective view of a fuel cell unit with two gaskets underneath, one for each fluid port;

[0093] Fig.11 yes Fig.10 a second perspective view of the arrangement of;

[0094] Fig.12 yes Fig.11 and 10 An overhead plan view of the arrangement;

[0095] Fig.13 and 14 is a cross-section through an assembled fuel cell unit, with gaskets where applicable, Fig.14 Force indicators are displayed to show compression during stacking (eg Figure 6 shown);

[0096] Figures 15 to 17 A second embodiment stack is shown which is similar to the first embodiment stack, albeit with an arrangement of differently shaped port features.

[0097] Figures 18 to 26 A third embodiment is shown, which is similar to the first embodiment, but in which the fuel cell unit has a separate section for the active fuel cell components - in which the electrochemically active layers are located, and in which the metal support plate of the fuel cell unit is provided with windows. Otherwise, the arrangement in these figures is similar to that in the first embodiment;

[0098] Figures 27 to 35 and Figures 18 to 26Similarly, but a fourth embodiment is shown having molded port features on the metal support plate as well as the divider plate, very similar to the second embodiment.

[0099] Fig.36 A fifth embodiment of the present invention is shown in which the external shape of the fuel cell unit has been changed to provide two fluid ports at each end of the fuel cell, rather than one fluid port as in the first embodiment.

[0100] Fig.37 Shown in more detail Fig.36 A corner of the product, where the molded port features are more clearly visible;

[0101] Fig.38 A sixth embodiment of the invention is shown wherein the fifth embodiment is adapted to include a pair of windows in its metal support plate to align two separate electrochemically active fuel cell assemblies;

[0102] Fig.39 An alternative arrangement of a fuel cell unit is shown in which the separator plate of the fuel cell unit has a returning flange peripheral feature extending rearwardly from the flange peripheral feature so that the edge of the separator plate is in the same plane as the majority of the separator plate so that the flange peripheral feature for forming a fluid volume in the fuel cell is ridged; the corners of the cell are also rounded;

[0103] Fig.40 A stack of fuel cell units clamped together is shown, with a power output that enables the fuel cells to be used as a power source for a load (L);

[0104] Fig.41 shows a perspective view of a battery cell stack prior to compression into a fuel cell stack;

[0105] Fig.42 An exploded view of a prior art fuel cell unit (from WO2015 / 136295) is shown, comprising a metal support plate and a separator plate, very similar to the present invention, but it additionally comprises a spacer plate;

[0106] Fig.43 and 44 Shows Fig.37 A variation of Fig.43 It is a partial plan view. Fig.44 are partial perspective views, both showing a corner of the product with a gasket used to cover a molded port feature around a fluid port;

[0107] Fig.45 and 46 Shows Fig.43 and 44 A cross-sectional view of a variant of Fig.46 yes Fig.45 An enlarged view of part A;

[0108] Figures 47 to 50 A similar view showing another variation, again with a gasket and molded port features around the fluid port, and with the addition of a hard stop feature; and

[0109] Figures 51 to 54 A similar view is shown of another variation, again with a molded port feature around the fluid port, but using an in-situ seal rather than a conventional grommet-style gasket.

[0110] First reference Figure 2 , showing an exploded view of a fuel cell unit and two gaskets according to a first embodiment of the present invention. Fig.42 The orientation of the prior art fuel cell unit is shown inverted because the present invention is primarily concerned with the interior of the fuel cell unit 10. It can be seen that the fuel cell unit 10 includes a flat (i.e., planar) metal support plate 14 that is stacked beside - in this case, on top of - the separator plate 12. The separator plate 12 is shown as having a flanged peripheral feature 18 at its periphery. This serves to make the prior art spacer plate 152 redundant and is an important element of the present invention.

[0111] The flange peripheral feature 18 extends out of the major plane of the sheet material to form a depression in the separator sheet (and a protrusion to the outer surface) as found in the central fluid volume area. The depression will form a fluid volume 20 within the fuel cell unit when the fuel cell unit is assembled.

[0112] In this illustrated arrangement (which is simplified to illustrate the main features of the invention), the fuel cell unit 10 has rounded ends and parallel sides, with a fluid port 22 at each end. Of course, other shapes, sizes and numbers of unit features are possible - see, for example, Fig.37 —Depending on the power and size required for the final stack assembly.

[0113] In the middle part of the fuel cell unit 10 , an electrochemically active layer 50 is provided on a metal support plate. In this embodiment, it is located outside the fluid volume 20 .

[0114] like Figure 3As shown, a plurality of small holes 48 are provided on the metal support plate 14 (e.g., a metal foil) to allow the fluid in the fluid volume to contact the side of the electrochemical layer closest to the metal support plate 14. These small holes form a porous area surrounded by a non-porous area. In a preferred embodiment, the anode (fuel electrode) layer is located near the small holes, and the (enclosed) fluid volume 20 in the fuel cell unit includes a fuel fluid volume 20, which is provided by the fuel entering and flowing out through the fluid port 22 (hence the fuel port 22). The cathode (air electrode) layer is located on the opposite side of the electrochemically active layer 50, that is, on its outer surface, and is exposed to the air flowing through the layer during the use of the fuel cell unit 10.

[0115] Both the separator plate 12 and the metal support plate 14 are provided with fluid ports 22. In the present embodiment, molded port features 24 are provided around the fluid ports of the separator plate 12. In the present embodiment, the molded port features 24 are provided as a plurality of elements in the form of circular depressions that extend from the bottom plane of the fluid volume 20 by a distance corresponding to the height of the flange peripheral features 18 - so that they have the same height. This is so that when the battery cell 10 is assembled, they will contact the opposing surface of the metal support plate 14, just like the flange peripheral features 18. Therefore, when the flange peripheral features 18 are connected to the metal support plate 14, for example by welding, the molded port features 24 will also contact the metal support plate 14 as well.

[0116] This is important because the molded port features 24 also provide part of the function of the spacer plates 152 provided in the prior art - supporting the fuel cell units during compression of the multiple fuel cell units in the stack together when the stack is assembled. Thus, they help maintain the height of the fluid volume within the fuel cell unit during this compression process.

[0117] The elements of this embodiment are circular in cross section and are substantially frustoconical in form, in that they have non-vertical side walls and truncated flat tops. They are pressed into the sheet of the divider 12. Such angled walls are a preferred arrangement because the angle is easier to achieve than vertical walls when pressing them out of the sheet forming the divider 12. However, any angle from about 20 degrees to 90 degrees may provide a usable form. Preferably, it is between 40 and 90 degrees from the plane of the sheet from which it is pressed.

[0118] Typically, these elements are pressed in the same step as the rest of the separator plate, namely the flange peripheral features and the central upward projection, and the downward or under projection, as described below.

[0119] Pressing may be any suitable method of forming the sheet into a suitable configuration, for example hydroforming or stamping / pressing. Thus, a single sheet may be used to form this portion of the fuel cell unit.

[0120] The compressive force in the stack near the electrochemically active layer is necessary for good electrical contact and therefore good conductivity through the stack. The central protrusion 32 and the central downward protrusion 30 extend downward to the opposite surface of the electrochemically active layer of the battery below it by extending upward to the bottom surface of the metal support plate 14 in the area of ​​the small hole 48, thereby forming the required electrical contact between the battery cells and also providing a support function for the fuel cell cells in the central area.

[0121] In this embodiment, the protrusions in the central region of the partition plate 12 are again circular, and also typically have inclined side walls. However, according to the prior art, they can have different shapes, such as strips of the prior art. They can have the same inclined side walls as the shaped port region, i.e. typically in the range of 20 to 90 degrees, or more preferably between 40 and 90 degrees.

[0122] However, the function of these central protrusions and downward protrusions is also to establish corresponding fluid channels, namely, fuel volume channels and oxidant (e.g., air) volume channels, on both sides of the separator plate 12. In this case, inside the fuel cell unit, these protrusions form a tortuous (e.g., curved) fluid channel within the fluid volume so that the fluid can pass from a fluid port 22 at one end of the fuel cell unit 10 through the active layer 50 to the fluid port 22 at the other end of the fuel cell unit 10.

[0123] This internal flow path also extends between the elements 26 of the molded port feature 24, as these elements also provide fluid passages 28 - see Figure 5 .

[0124] In the present embodiment, a seal in the form of a gasket 34 is also provided for the fuel cell stack between adjacent fuel cell units 10 . Figure 2 and Figure 3Some examples are provided in . The seal (here the gasket 34) provides the primary sealing function and is typically a compressible gasket that is subject to high compressive forces in the vicinity of the port. The gasket may be sized to cover all of the molded port features 24 of each fluid port 22 to prevent fluid flowing through the fluid port 22 in the stack between the exterior of the fuel cell unit 10 and the gasket 34 from seeping into areas outside the cell, i.e., into the fluid surrounding the fuel cell unit 10, or fluid outside the fluid port from seeping into the fluid port from the other direction. This is important to prevent mixing of fluid inside the cell 10 with fluid outside the cell 10 (this would be the fuel and oxidant), the polarity of the electrochemically active layer 50 determining which way this will be. As discussed above, typically within the fluid volume 20 of the fuel cell unit 10 is the fuel and therefore within the vents 72, 74 (see FIG. 1 ) formed by the fluid ports and gasket (annular gasket). Fig.40 and 41 ) contains the fuel, while surrounding the fuel cell unit is air or other oxidant.

[0125] The gasket may also provide electrical insulation between a first fuel cell unit 10 and an adjacent flow cell unit 10 to prevent short circuits. The gasket may be any suitable fuel cell gasket (sealing ring), for example, thermite.

[0126] Reference Figure 5 and Figure 6 , it can be seen how the flange perimeter feature 18, the center protrusions (upper and lower protrusions) 32, 30, and the formed port feature 24 extend out of the original plane of the metal sheet used to form the separator plate 12, and how the diameter of the gasket 34 is sized to cover the area of ​​the formed port feature 24, which is pressed upward out of the bottom surface of the separator plate 12 - that is, away from the gasket 34 to leave a void. In this arrangement, when pressure is applied to the battery cells 10 in the assembled battery cell stack, the formed port feature 24, together with the flange perimeter feature 18 and the center protrusions 30, 32, support and prevent the fluid volume from being squeezed and deformed.

[0127] In the prior art, the support function of the molded port feature 24 in conjunction with the flange perimeter feature 18 is instead performed by the spacer plate 152. In particular, the spacer plate ensures that the high loads of the gasket compression near the port are transferred to the next fuel cell unit.

[0128] Additionally, the formation of the internal fluid volume 20 is accomplished by the flange perimeter feature 18 - a feature previously provided by the spacer plate 152. However, the footprint of the original part cut from the spacer plate is large, resulting in wasted material.

[0129] Reference Figure 4 , Figure 5 and Figure 6It can also be seen that the central upward protrusions 32 in the separator plate 12 alternate with the central downward protrusions 30. This is to allow the downward protrusions 30 to extend downward to the upper electrochemically active layer 50 of the adjacent fuel cell (below it). Figure 7 and Figure 8 As shown more clearly in FIG. 1 , it can be seen that the central upward protrusion 32 extends upward to the bottom surface of the metal support plate 14 of its own fuel cell unit 10, while the downward protrusion 30 contacts the outer side of the electrochemically active layer 50 of the fuel cell unit 10 below it. This ensures that adjacent fuel cell units 10 are connected in series like batteries in each stack. It has a beneficial function, that is, to expand the height of the fluid volume channel in the fluid volume.

[0130] Next reference Figure 8 , it can be seen that adjacent fuel cell units 10 preferably have separator plates with mutually matching opposing protrusions so that the upward protrusion 32 on one fuel cell unit 10 is aligned with the downward protrusion 30 on the adjacent fuel cell unit 10, and the downward protrusion 30 is aligned with the upward protrusion 32. This allows the forces of the individual protrusions to offset each other in the axial direction (i.e., parallel to the compressive forces applied to the stack during assembly). This avoids or minimizes torsional forces on the electrochemically active layer 50 between the protrusions, thereby preventing accidental cracking of the electrochemically active layer.

[0131] Please refer to the following Figures 9 to 17 , a second embodiment of the invention is disclosed. In this embodiment, there is still a separator plate 12 and a metal support plate 14, similar to the first embodiment, but the molded port features 24 are now arranged around the fluid ports 22 of the metal support plate 14 and the separator plate 12. Therefore, the height of the elements in the separator plate 12 is not as high as in the previous embodiment, and the individual, aligned molded port features 24 are arranged to face downward from the metal support plate 14, the latter of which is suitable for forming a height equal to the overall height in the first embodiment when combined with the elements of the separator plate 12. By aligning them with each other, the volume inside the fuel cell unit 10 can again be maintained at the height of the two stacked elements, while still providing the required support for the fluid volume channels near the ports where the compressive forces are particularly high in the assembled stack. Compared with the previous embodiment, the rest of this arrangement is unchanged.

[0132] Typically, the heights of the two elements are different from each other but together form the desired overall height, however they can be matched to achieve the desired overall height.

[0133] With the arrangement of the second embodiment, the formed port features 24 in any particular part need not be so high, and therefore are more easily accomplished when pressing them out of the sheet material.

[0134] The formed port feature 24 may also be located in only the metal support plate 14, or both may be of sufficient height and have them intermesh, while still leaving a fluid passage in the fluid volume for fluid flow.

[0135] In this second embodiment, as in the previous embodiment, the molded port feature 24 and the central upper and lower protrusions 30, 32 are all dimples having rounded shapes. They can have different shapes, but dimples are preferred because they provide large channels for the flow of fluid, which is particularly important for the molded port features 24 because they are therefore less likely to form channels between the gasket and the other side of the part they are pressed into, otherwise the fluid in the port can leak through these channels into the surrounding volume of the battery cell 10, or vice versa.

[0136] Next reference Figures 18 to 26 , a third arrangement of the fuel cell unit 10 is provided. In this embodiment, similar to the first embodiment, the shaped port features 24 and the central protrusions 30, 32 are again provided in the separator plate 12, so that the metal support plate 14 is instead generally flat or at least lacks such protrusions, but previously the metal support plate 14 had a number of small holes 48 in the central region with the electrochemically active layer 50 directly overlying it, in this embodiment, the metal support plate 14 has a window 54 on which a separate electrochemically active layer component 52 will be located. Although formed separately, the electrochemically active layer component 52 will be connected to the metal support plate 14 (e.g., by welding) so that the metal support plate carries it.

[0137] Electrochemically active layer member 52 has a plurality of apertures therein and directly overlies electrochemically active layer 50 so that fluid in fluid volume 20 can contact the innermost electrochemical layer.

[0138] This embodiment still only involves joining the two components at the peripheral flange feature, but does not require the fuel chemistry to be integrally formed with the metal support plate from the outset, which may be advantageous.

[0139] Laser welding is generally the preferred means of connecting the metal support plate 14, the separator plate 12, and the separate electrochemically active layer components 52 to one another.

[0140] In this third embodiment, the window is rectangular. Other shapes of windows are naturally possible.

[0141] Electrochemically active layer member 52 is generally of similar shape to window 54 to optimize the size of electrochemically active layer 50 thereon, although larger sizes may overlap as shown. This again avoids excessive weight increase to fuel cell unit 10.

[0142] from Fig. 20As can be seen in the figure, the electrochemically active layer member 52 has many small holes 48, much like the small holes in the metal support plate 14 of the first and second embodiments. They also provide access to one side of the electrochemically active layer 50 thereon. Therefore, the operation of this fuel cell unit in a stack is similar to the previous embodiments and the prior art, although in this embodiment, the upward protrusions 32 need to be higher than in the previous two embodiments because they now also need to make up for the thickness of the metal support plate 14 in order to contact the bottom side of the small holes 48.

[0143] Then refer to Figures 27 to 35 , a fourth embodiment is shown. In this embodiment, the arrangement is similar to the second embodiment, but it includes an electrochemically active layer component 52 that is independent of the third embodiment itself. Therefore, again, the upward protrusion 32 is higher than in the first and second embodiments. It will be appreciated that before the fuel cell chemicals supporting the electrochemically active layer component 52 are attached to the metal support plate 14, the metal support plate 14 can be pressed and the window 54 cut. The window can be cut before or after pressing, or simultaneously on a press with a punch. More typically, it will be cut from the metal support plate with a laser.

[0144] All four embodiments show a preferred arrangement of the elements forming the port features 24. As can be seen, they take the form of circular dimples. Furthermore, the circular dimples are arranged in concentric rings around the fluid port 22, with circumferential gaps between them, with the gaps between the dimples increasing as they go further outward (from the fluid port 22). This is an arrangement suitable for circular fluid ports, although different arrangements are possible, such as a regular arrangement, or an irregular arrangement, or different numbers or sizes of dimples, or different numbers of rings.

[0145] In these embodiments, each concentric ring of dimples has 10 dimples, and each concentric ring of dimples is rotated on the basis of the previous dimples so as to be staggered relative to them. This can be arranged differently for each ring, or as shown in the figure, the inner concentric ring and the third concentric ring are aligned radially, while the second concentric ring is located between two adjacent dimples of the first concentric ring, and similarly, the two dimples of the second concentric ring are also spaced apart.

[0146] In this and preferred arrangement, a tortuous rather than a linear fluid path is formed from the fluid port 22 to a location outside the concentric rings (or formed port features 24).

[0147] It is preferred to have a larger gap between the elements as the elements are located radially farther from the fluid port 22, and a closer gap as they are located closer to the fluid port 22. This larger "outer" gap ensures greater freedom for fluid to move in the fluid passages between the dimples, but more importantly, it provides a more complete surface near the edge of the gasket against which the gasket 34 can provide a good seal.

[0148] The gasket 34 can be compressed when the stack is assembled so as to deflect into the depression left by the depression pressed into the sheet material of the separator plate 12 (or metal support plate 14). This further forms a good seal between the fluid port vents and the volume surrounding the fuel cell units in the stack.

[0149] The external shape of the fuel cell unit 10 does not need to match the first to fourth embodiments. In fact, there are many variations available to the skilled person. The present invention is intended to cover any and all of these different shapes. For example, it may not be the elongated type shown herein, but more like a rectangle, with fluid ports at four corners, or it may be a diamond, with fluid ports at two corners, or it may be an ellipse, with fluid ports at both ends of its longer spacing.

[0150] Fig.36 Another possible shape of the fuel cell unit 10 is shown, in which the separator plate 12 and the metal support plate 14 are generally rectangular, although there are cutout areas at their short ends to define two extended fingers at each end. A fluid port 22 is provided at each end of the two fingers.

[0151] Some embodiments may have more fingers, or more ports.

[0152] In the fifth embodiment, the flange perimeter feature 18 is again provided, as is the shaped port feature 24 in the separator plate 12. In addition, the protrusions 30, 32 extend alternately upward and downward throughout the central region of the separator plate to achieve the purpose previously disclosed with respect to the previous fourth embodiment. In addition, there is an electrochemically active layer 50 on the metal support plate 14. By providing two fluid ports 22 at both ends, the fluid flow within the fluid volume within the SOEC or SOFC fuel cell unit 10 can be better guided.

[0153] Next reference Fig.37 , showing Fig.37 Detail of the corner of the fuel cell unit 10. It can be seen that the gasket 34 for the fuel stack is also shown. It is sized to cover all the molded port features 24, which in this embodiment include dimples around the fluid port 22. The dimples can be several concentric rings, such as four concentric rings of staggered circular dimples.

[0154] Other arrangements of the formed port features 24 may also be provided, such as the arrangements of the first through fourth embodiments.

[0155] Next reference Fig.38 , the figure shows Fig.36 An improved version of the product in which two windows 54 are provided, which are arranged end to end for receiving two independent electrochemically active layer components 52.

[0156] Other embodiments may have more than two window and electrochemically active layer components.

[0157] Next reference Fig.39 , a further modification of the fuel cell unit 10 of the present invention is shown in the figure, wherein a pressed flange peripheral feature 18 is located on the inside of the edge of the fuel cell unit 10 so as to form an upward protrusion or ridge relative to the edge and middle of the separator plate 12 or the metal support plate 14 (if it is instead arranged above the metal support plate or above both).

[0158] Next reference Fig.40 , shows a fuel cell stack consisting of a plurality of fuel cell units 10. It can be seen that it has a top compression plate 62 and a bottom compression plate 64, which are connected together by bolts 66 to allow the battery unit 10 to be compressed together, thereby ensuring electrical connection between the central protrusion and the porous area / electrochemically active layer, thereby completing the use of each electrochemically active area. In addition, it shows an inlet position 68 and an outlet position 70 so that air or fuel fluid enters downwardly into a first vent 72 formed by a first group of gaskets 34 and a row of all first fluid ports, and then comes down from a second vent 74 formed by a second group of gaskets 34 and a row of all second fluid ports. However, it is understood that the fluid inlet and outlet can be arranged in other ways relative to the vents 72, 74, for example, all at the top or bottom, or the fuel cell stack can be mounted on its side (or at a certain angle).

[0159] Fig.40 Also shown are contact pads 60 at the top and bottom of the stack, illustrating possible locations for connecting the stack to a power demand, such as a load L as shown.

[0160] Next reference Figures 43 to 46 , showing a modified corner arrangement. Fig.37 As in the embodiment of the present invention, there is a fluid port 22 surrounded by a molded port feature 24 and a gasket 34, which is used to cover the groove formed by the molded port feature 24 during assembly, such as Fig.43As shown, the gasket 34 has an outer diameter that covers at least the outer edge of the molded port feature 24, but has an inner diameter that is larger than the fluid port 22. Although optional, this prevents the inner diameter of the gasket 34 from blocking the vent formed by the fluid port in the final fuel cell stack if the gasket is slightly misaligned relative to the center of the vent.

[0161] The formed port feature 24 extends downwardly to contact the metal support plate 14 with its lowermost surface located in a first plane, in the same plane as the flange peripheral feature 18 , and its uppermost surface and the remainder of the divider plate 12 located in a second plane spaced apart from the metal support plate 14 to define the fluid volume 20 .

[0162] In this embodiment, the molding port feature 24 has grooves in the innermost area, and these grooves are open to the fluid port 22. Then two staggered circular groove rings, followed by the grooves and circular grooves of the last ring alternately, the length of these grooves is approximately twice of the circular groove diameter. In this embodiment, the groove is aligned radially with the circular grooves in the inner side in two staggered rings, and is staggered relative to the innermost groove. The last ring circular groove is radially aligned with the second circular groove in the two staggered rings on the contrary. This arrangement forms a passage that allows fluid to flow between the grooves inside the fuel cell unit (entering the fuel cell unit inside from the fluid port, or flowing in the opposite direction when ventilated).

[0163] Although this embodiment is shown for one corner of the fuel cell unit, it can replace Fig.36 , 38 39, but this arrangement of grooves and recesses can also be applied to other fuel cell unit designs, including those with single fluid ports at both ends, such as Figure 1 design.

[0164] Next reference Figures 47 to 50 , shows another variation of the fuel cell corners, although this could also be provided on different fuel cell designs, such as elsewhere in the fuel cell unit shape, i.e. a fuel cell unit with four fluid ports, one fluid port per corner (e.g. Fig.36 , 38 and 39, or having two fluid ports, one at each end (e.g. Figure 1 embodiments)), or any other fuel cell design, including fuel cells having any other number of fluid ports.

[0165] In this variation, in addition to the grooves and / or channels that form the molded port features 24, raised members 120 are provided. These raised members 120 are located in a ring around the periphery of the gasket 34 and in this embodiment provide two functions.

[0166] Firstly, they provide a guide for the position of the gasket, as the gasket can be mounted inside the ring of the protruding member 120 and thus positioned in the correct position relative to the fluid port 22 during assembly of the fuel cell stack, ie centered relative to the fluid port 22 .

[0167] Secondly, if Fig.49 and 50 As shown, the height h of the protruding member 120 is less than the thickness t of the gasket 34, or preferably between 75% and 99% of the thickness t, or more preferably between 75% and 85% (e.g., 78% to 82%). The ratio of the height h to the thickness t can be adjusted according to the compression requirements of the specific gasket used. Although such a large height h is not necessary to provide the first function, so it can be less high (e.g., h can be between 5-75% of the gasket thickness t), a larger height is preferred to provide the second function, namely, to provide a hard stop during assembly and stacking. This hard stop function is helpful during the manufacturing process of the fuel cell stack because the gasket is compressible, so that it can be sealed against the grooves on the outer surface of the fuel cell unit when compressed, there is a possibility of over-compressing the stack during assembly, and this over-compression may cause the electrochemically active layers on the metal support plate to rupture or otherwise damage because the central protrusion 30 is also brought into contact with these electrochemical layers during the gasket compression process. By providing a hard stop, a limit can be set for the degree of compression so that excessive compression is resisted by the hard stop, thereby preventing unintentional cracking of the electrochemically active layer on the metal support plate (thereby providing better tolerance for the bonding pressure between the central protrusion and the electrochemically active layer within the fuel cell).

[0168] However, it is important that the height of these protruding members 120 does not exceed the thickness t of the gasket 34, otherwise, during the stacking process, the gasket cannot be compressed and, likewise, electrical connection between the electrochemically active layer and the central protrusion may not be achieved, thereby preventing effective operation of the stack and introducing potential hot spots therein. However, the actual height h of the protruding members 120 can be varied or set appropriately to achieve the necessary compression of the gasket during assembly to achieve proper connection between the electrochemically active layer and the central protrusion to ensure proper sealing of the gasket to the groove on the outer surface of the fuel cell unit and proper electrical connection of the entire central protrusion 30. An electrically insulating coating or adhesive layer can be used on one or both of the mating surfaces of adjacent fuel cell units (the hard stop surface formed by the protruding members 120 and the metal sheet of the adjacent fuel cell unit) to prevent electrical contact between adjacent fuel cell units through the mating surfaces.

[0169] In a variation thereof, the washer 34 has no protruding member on its periphery, but instead has a shape or hole on its interior to accommodate the protruding member 120, thereby again providing the washer with a fixed position relative to the protruding member 120, and possibly providing a potential fixed orientation of the washer relative to the protruding member (or multiple fixed orientations, if the washer can be adapted to multiple fixed orientations).

[0170] In a variation thereof, a protruding member 120 around the periphery of the gasket is formed on the metal support plate 14, extending toward the separator plate 12 of the adjacent fuel cell unit. In another variation, the protruding members are formed on the metal support plate 14 and the separator plate 12, and these protruding members may be spaced apart from each other. In addition, the protruding members on the metal support plate 14 and the separator plate 12 may be of medium height and arranged so that their protruding features are adjacent to each other to form a situation having the same total height as the height of the protruding members on the separator plate 12 or the metal support plate 14, or spaced apart from each other on the separator plate 12 and the metal support plate 14.

[0171] See next Figures 51 to 54 , another variation of the corner is shown. In this embodiment, an annular groove 122 is provided around the fluid port 22 instead of a (prefabricated) gasket to accommodate the in-situ sealing material. Fig.52 1. The groove 122 is shown having a depth less than the recesses 24 of the molded port features on either side of it because it need not form a barrier to the flow of fluid from the fluid ports 22 into the interior space of the fuel cell unit.

[0172] The grooves 24 are again provided, arranged in the form of concentric rings. In this case, one ring is outside the annular groove and one ring is inside the annular groove, the latter being in the form of a groove at the edge of the fluid port. As in the previous embodiment, additional grooves or groove rings may also be provided. However, for the sake of clarity, only two rings are shown so that the annular grooves can be most clearly seen.

[0173] Although in this embodiment the annular groove is formed into a uniform circular shape with a constant depth, it is possible to make the radius and depth of the annular groove less uniform, but for simplicity, a uniform radius and depth are provided.

[0174] Reference again Fig.51 , it can be seen that the annular groove 122 is now covered by an in-situ seal, i.e. a ring of sealing material 124. This material 124 can be a liquid or an adhesive used during the assembly of the stack. It can be any conventional sealing contact adhesive which, after hardening, can withstand the operating environment of the fuel cell. If desired, it can also be replaced by a (prefabricated) gasket, but the use of an in-situ seal has the significant advantages of reducing the number of parts, reducing costs and simplifying assembly, since the gasket no longer needs to be carefully positioned.

[0175] Please also refer to Fig.53 and 54 , Fig.54 1 is a more detailed view, it can be seen that the annular groove 122 accommodates a volume (or pellet) of sealant material 124, which also extends in an annular manner to the upper surface of the molded port feature, thereby acting similarly to the gasket 34 in the previous embodiment. With this arrangement, the thickness of the sealant material 124 can be significantly lower than the thickness required for a typical preformed gasket. Similarly, an electrically insulating seal can be used, or alternatively an electrically insulating coating or adhesive layer can be used on one or both of the mating surfaces of adjacent fuel cell units (such as the surface of the hard stop formed by the protruding portion 126 of the adjacent fuel cell unit and the metal sheet) to prevent electrical contact between adjacent fuel cell units through the mating surfaces.

[0176] The thickness of the gasket 34 in the previous embodiment helps to provide space between adjacent fuel cell units for air or fuel flow. In order to retain this space, a molded port feature 24 can be provided in the protruding portion 126 of the separator plate 12, such as Fig.52 , 53 and 54. This also ensures that the final height of the top of the gasket sealing material remains the proper height to allow the outer surface of the electrochemically active layer to properly align and contact the top of the outwardly extending central protrusion 30 during compression or clamping of the stack into the final assembled position.

[0177] Groove 122 Fig.54As shown, the groove has a depth d that is less than the depth of the grooves 24 on both sides because it does not need to form a barrier for the fluid to flow from the fluid port 22 into the fluid volume 20 of the fuel cell unit. Preferably, the depth d of the groove 122 is less than the depth d2 of the protrusion 126. Also preferably, the depth d of the groove is between 5-75% of the depth d2 of the protrusion 126. Typically, this can correspond to the groove 122 extending into the space between the metal support plate and the separator plate, with a depth between 5-80% of the extension depth of the groove 24, or more preferably between 10-50%, and more preferably less than 50%. The depth can be measured from the outside, such as Fig.54 As shown in d and d2 in FIG. 1 , it can also be measured at the internal height of the internal space of the fuel cell unit.

[0178] The raised portion 126 where the annular groove 122 is located can serve as a hard stop feature, similar to Figures 47 to 50 Of course, in addition to the annular groove, a protrusion may also be included to provide a hard stop feature similar to Figures 47 to 50 The invention also provides a hard stop feature to help avoid over-compression of the sealing material / stack. Likewise, it may even be possible to surface mount without the use of an annular groove, for example by using a liquid applied sealing material on a flat annular surface rather than a pre-formed gasket. However, the absence of a groove may result in a greater likelihood of seal failure because the groove provides a volume into which a portion of the sealing material may be pushed (seated) during compression, while without the groove, the sealing material may be pushed away from the sealing surface area due to, for example, slight misalignment of the stack. A seal failure would allow fuel and air to mix within the stack, which is undesirable. Therefore, an annular groove is more preferred as a solution to provide a longer service life for the stack during use.

[0179] Finally, reference Fig.41 , illustrates a stack of fuel cell units according to a first embodiment. This is before any housing or compression bolts or top and bottom plates 62, 64 are added. This is to illustrate the vents (here internal manifolds formed by multiple aligned ports and aligned gaskets) 72, 74, through the top of which the inner edges of the metal support plate 14, separator plate 12 and gasket 34 can be seen. Fluid in the vents can enter the fluid volume 20 within each fuel cell unit 10, the fluid volume between the metal support plate 14 and separator plate 12 of each fuel cell unit, but cannot enter between adjacent fuel cell units 10 due to the gasket 34, while fluid outside the fuel cell units can enter the space between adjacent units, except at the gaskets and vents, such as shown by arrow 76, because the sides / edges between them are open.

[0180] In summary, a metal-supported fuel cell unit 10 is provided, including a separator plate 12 and a metal support plate 14 (such as a stainless steel foil carrying a chemical layer 50), which overlap each other to form a repeating unit, at least one plate having a flange peripheral feature 18 formed by pressing the plates, the plates directly connected at the flange peripheral feature, forming a fluid volume 20 between them, each plate having at least one fluid port 22, wherein the ports are aligned and connected to the fluid volume, and at least one plate has a pressed molded port feature 24 extending around its port toward another plate and including elements spaced apart from each other to define a fluid channel so that fluid can enter the fluid volume from the port. Thus, the stack can be formed by a minimum number of different, multifunctional components. The protruding member 120, which is also formed by pressing, can receive a gasket 34 as a hard stop or as a sealing bearing surface.

[0181] Alternative arrangements and shapes would also be within the scope of the invention, for example, where square fingers are provided rather than round fingers. Likewise, as a set of components, the shape of the molded port features need not match the shape of the battery cell area provided to them, as fluid exiting the fluid passages can circulate around any gaps between the component set and the flange peripheral features.

[0182] The above description of these and other features of the invention is purely illustrative. The invention may be modified in detail within the scope of the claims, particularly with respect to the shape of the fuel cell unit, the arrangement of the electrochemically active layer and the shaped port features and the central protrusion elements for allowing fluid to flow between the fluid ports within the fuel cell unit.

[0183] List of reference numerals: Prior art

[0184] 90 - Fuel Cell

[0185] 110 - Metal support plate

[0186] 150 - Divider

[0187] 150A - Up and down ripple

[0188] 152 - Spacer

[0189] 160 - Large Space / Hole

[0190] 180 - Fluid Port

[0191] 200 - Fluid Port

[0192] The present invention

[0193] 10 - Fuel Cell

[0194] 12 - Divider

[0195] 14 - Metal support plate

[0196] 18 - Flange peripheral features

[0197] 20 - Fluid Volume

[0198] 22 - Fluid Port

[0199] 24 - Molded Port Features

[0200] 26 - Components of the Molded Port Feature

[0201] 28 - Fluid Channel

[0202] 30,32 - Central protrusion

[0203] 34 - Washer

[0204] 48 - Small hole

[0205] 50 - Electrochemically active layer

[0206] 52 - Individual parts

[0207] 54 - Window

[0208] 58 - Ridge

[0209] 60 - Contact pad

[0210] 62 - Top Compression Plate

[0211] 64 - Bottom compression plate

[0212] 66 - Bolt

[0213] 68 - Entrance location

[0214] 70 - Exit location

[0215] 72 - First Airway

[0216] 74 - Second airway

[0217] 120 - protruding member

[0218] 122 - Annular groove

[0219] 124 - In-situ seal

[0220] 126 - protrusion

[0221] h - height of the protruding member

[0222] t - Washer thickness

[0223] d - Groove depth

[0224] d2 - protrusion depth

Claims

1. A metal-supported solid oxide fuel cell unit, comprising: Dividers; and A metal support plate carrying a fuel cell chemical layer disposed on the porous region; The partition plate and the metal support plate overlap each other to form a repeating unit; Features: At least one of the separator plate and the metal support plate includes a flange peripheral feature formed by pressing the plate into a concave configuration; The separator plate and the metal support plate directly meet at the flange peripheral feature to form a fluid volume therebetween; at least one fluid port is disposed within the flange perimeter feature of each of the separator plate and the metal support plate, the respective fluid ports being aligned and in communication with the fluid volume; and At least one of the separator plate and the metal support plate has a molded port feature formed by pressing around its port and extending toward the other plate, and the elements of the molded port feature are spaced apart from each other to define a fluid passage from the port and located between the elements to enable fluid to pass from the port to the fluid volume.

2. The metal-supported solid oxide fuel cell unit according to claim 1, characterized in that: The fuel cell chemical layers take the form of electrochemically active layers including an anode, an electrolyte, and a cathode formed on and above a porous region within the metal support plate.

3. The metal-supported solid oxide fuel cell unit according to claim 1, characterized in that: The porous area is arranged on a separator plate, the fuel cell chemical layer is formed on the separator plate, the fuel cell chemical layer takes the form of an electrochemically active layer, the electrochemically active layer includes an anode, an electrolyte and a cathode, and the separator plate is arranged on the window of the metal support plate.

4. A metal-supported solid oxide fuel cell unit according to any preceding claim, characterized in that The fluid pathways leading from the fluid ports to the fluid volume are tortuous and / or intersect each other at multiple locations.

5. The metal-supported solid oxide fuel cell unit according to any one of claims 1 to 3, characterized in that: The flange perimeter feature is provided only on the separator plate.

6. The metal-supported solid oxide fuel cell unit according to any one of claims 1 to 3, characterized in that: The formed port features are provided only on the divider plate.

7. The metal-supported solid oxide fuel cell unit according to any one of claims 1 to 3, characterized in that: The height of the formed port feature above the surface from which it extends is the same as the distance between the opposing inner surfaces of the two plates.

8. The metal-supported solid oxide fuel cell unit according to any one of claims 1 to 3, characterized in that: At least one of the separator plate and the metal support plate is provided with one or more protruding members formed by pressing and extending away from the other plate and arranged around the or each fluid port.

9. The metal-supported solid oxide fuel cell unit according to claim 8, characterized in that: A plurality of protruding members are included, the plurality of protruding members being arranged to define a space for receiving a gasket within the protruding members and / or the plurality of protruding members being arranged to define a perimeter for receiving a gasket outside the protruding members.

10. The metal-supported solid oxide fuel cell unit according to claim 8, characterized in that: A plurality of protruding members are interspersed between the molded port features.

11. The metal-supported solid oxide fuel cell unit according to claim 8, characterized in that: The or each protruding member is located externally of the profiled port feature.

12. The metal-supported solid oxide fuel cell unit according to any one of claims 9 to 11, characterized in that: The or each protruding member has a top end defining a hard stop surface against which an adjacent fuel cell unit, or a portion extending therefrom, can abut during assembly of a stack of the units.

13. The metal-supported solid oxide fuel cell unit according to claim 12, characterized in that: A plurality of raised members defining hard stop surfaces are included, and the hard stop surfaces all lie within a common plane.

14. The metal-supported solid oxide fuel cell unit according to any one of claims 1 to 3, 9 to 11, and 13, characterized in that: The separator plate and the metal support plate are directly connected at the flange peripheral feature by welding around the flange peripheral feature.

15. A solid oxide fuel cell stack comprising a plurality of fuel cell units according to any one of claims 1 to 14, the fuel cell units being stacked on each other, and seals being provided around fluid ports between adjacent fuel cell units, the seals optionally covering the molded port features.

16. The fuel cell stack according to claim 15, characterized in that: The seal includes a gasket.

17. The fuel cell stack according to claim 15, characterized in that: The seal comprises an in-situ seal.

18. The fuel cell stack according to any one of claims 15 to 17, characterized in that: The fuel cell unit is a fuel cell unit according to claim 12, wherein at least one seal on the sealing receiving surface of a lower one of the fuel cell units has a height higher than the sealing receiving surface before the next fuel cell unit is stacked thereon, and the hard stop surface of the lower one of the fuel cell units has a height higher than the sealing receiving surface but lower than the seal located on the sealing receiving surface so as to provide limitation for compression between adjacent fuel cell units.

19. The fuel cell stack according to any one of claims 15 to 17, characterized in that: At least one of the seals is partially located in a groove surrounding a fluid port corresponding to the seal, the groove optionally being located in a raised portion of the plate.

20. The fuel cell stack according to any one of claims 15 to 17, characterized in that: The internal components of the fuel cell stack include only the cell stack and the seal, which optionally overlies molded port features around the respective fluid ports.

21. The fuel cell stack according to any one of claims 15 to 17, characterized in that: The stamped and formed port features define recessed holes on the outer surface of the plate from which they are formed, the holes of each set of molded port features being covered by one of the seals, the holes optionally being located in a raised portion of the plate.

22. A method for manufacturing a metal-supported solid oxide fuel cell unit, the method comprising the steps of: Provide dividers; providing a metal support plate; and processing at least one of the metal support plate and the separator plate to form: Flange peripheral features; at least one fluid port in said separator plate and said metal support plate; as well as at least one formed port feature formed around the at least one fluid port, The processing includes at least pressing the plate or plates to form the flange perimeter feature, thereby forming a concave structure in the plate or plates, and likewise pressing the molded port feature; The method further comprises: stacking the separator plate and the metal support plate on each other to form a repeating unit; The separator plate and the metal support plate are directly connected at the flange peripheral feature, wherein the flange peripheral feature forming the concave structure forms a fluid volume therebetween, wherein the molded port feature extends toward another plate and the molded port feature is an element are spaced apart from each other to provide a fluid passage from the port to the fluid volume, and optionally Wherein, the fluid port is cut prior to pressing the plate or multiple plates to form the flange peripheral feature.

23. The method according to claim 22, characterized in that The fuel cell unit is consistent with the fuel cell unit of any one of claims 1 to 14, or the stack is a stack as defined in any one of claims 15 to 21.

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