Sealing assembly for a fuel cell

Abstract

The invention relates to a sealing assembly (10) for a fuel cell (20), having a support plate (1) and a sealing portion (2) provided on one face (1.1) of the support plate (1) for limiting a medium flowing along the support plate (1). A counter portion (3) is provided on the face (1.2) of the support plate (1) opposite the sealing portion (2). The support plate (1) has at least one cutout (1.3) which connects one face (1.1) to the other face (1.2) and passes through the support plate (1), and the sealing portion (2) is connected to the counter portion (3) so as to interlockingly engage with the support plate (1) through the cutout (1.3). The invention further relates to a fuel cell (20) and to a method for producing a sealing assembly (10).

Description

[0001] Sealing arrangement for a fuel cell

[0002] The invention relates to a sealing arrangement for a fuel cell comprising a carrier plate and a sealing section arranged on one side of the carrier plate for limiting a medium flowing along the carrier plate. The invention further relates to a fuel cell and a method for manufacturing a sealing arrangement.

[0003] Such sealing arrangements can be used in various fields of technology. A typical application is fuel cells, especially polymer electrolyte fuel cells, which are also used in many areas of technology and have a layered structure consisting of several stacked plates with very thin channels to achieve the highest possible power density. In these fuel cells, a medium typically flows between two plates, which can then react with another medium in a reaction zone. To prevent leaks, it is necessary to seal the channels or the spaces between the two plates so that the media only flow in predetermined areas and, in particular, cannot escape from the channels unintentionally.

[0004] In practice, sealing arrangements are used that have a sealing section attached to one side of a plate, for example, in a fuel cell. This plate is subsequently referred to as the carrier plate. Since the plates are usually made of metal and the sealing sections of plastic, an adhesion promoter is required between the metal and plastic to ensure the sealing section adheres reliably to the metal plate. However, this adhesion promoter has proven disadvantageous in practice, particularly with regard to manufacturing, for several reasons. Firstly, not only are the manufacturing costs comparatively high due to the required adhesion promoter, but the applied adhesive is also usually not easy to remove from the metal surface. If the plate, for example,If the adhesive is to be reused or recycled, complex etching or pickling processes must be used to remove the residues. Furthermore, chemicals from the adhesive can dissolve in the flowing media, which, especially after prolonged use, can lead to partially unacceptable contamination of the media. Therefore, the invention aims to provide a sealing arrangement characterized by an improved connection between the sealing arrangement and the carrier plate.

[0005] This problem is solved in a sealing arrangement of the type mentioned above by arranging a counter-section on the side of the carrier plate opposite the sealing section, wherein the carrier plate has at least one recess connecting one side with the other side and passing through the carrier plate, and wherein the sealing section is connected to the counter-section through the recess for a positive connection with the carrier plate.

[0006] This design allows the sealing section to be reliably bonded to the carrier plate without the use of an adhesion promoter. The disadvantages associated with using an adhesion promoter are avoided, and manufacturing is significantly simplified. The positive-locking connection ensures that the sealing section cannot move relative to the carrier plate and that a reliable seal is guaranteed at all times, even under high pressures and temperatures. Furthermore, the mating section cannot move relative to the carrier plate due to the connection with the sealing section, as the sealing section and the mating section are positively locked to the carrier plate via the at least one recess.

[0007] Furthermore, the elimination of the adhesion promoter allows the use of materials on the carrier plate that are generally incompatible with adhesion promoters. In this respect, the inventive compound also opens up additional design possibilities for the carrier plate. The carrier plate can be made of steel or aluminum, but also, for example, of titanium, which is generally less suitable for adhesion promoters.

[0008] Regarding the connection between the sealing section and the mating section, it has proven advantageous for the sealing section and the mating section to be integrally joined. This ensures a highly reliable connection between the two elements, which in turn guarantees a secure, form-fitting hold on the carrier plate. The sealing section and the mating section can therefore be made of the same material or at least of materials that cross-link with each other. Advantageously, both elements are made of plastic, particularly an elastomer. Due to the integral connection, there is no interface between the mating section and the sealing section.

[0009] According to an advantageous embodiment of the invention, the opposing section is designed as a second sealing section. Analogous to the sealing section, the opposing section can also be designed as a sealing section, so that a sealing effect can be generated on both sides of the carrier plate. The sealing section arranged on the first side of the carrier plate can therefore be referred to as the first sealing section, and the other sealing section arranged on the correspondingly opposite side as the second sealing section. The embodiments for the first sealing section also apply to the second sealing section. The two sealing sections can be identical or different in design. For example, the sealing sections can differ with regard to the number of their sealing lips.

[0010] Furthermore, counter sections can also be provided on both sides of the carrier plate, e.g. to maintain only a separating layer at a predefined distance to the carrier plate on both sides, without simultaneously achieving a sealing effect, as will be explained in more detail below.

[0011] Furthermore, it is possible to arrange not only a sealing section or a counter-section on one side of the carrier plate, but also both a sealing section and a counter-section on one side of the carrier plate. The two sections can connect to each other and, in particular, be integrally joined. In areas where a seal is required, a sealing section can be provided accordingly, and in other areas where, for example, no sealing effect is required, but only a predefined distance between the carrier plate and a separating layer, a counter-section can be provided. On the opposite side of the carrier plate, the sealing section and the counter-section can then be connected to each other separately or together with a sealing section or a counter-section via one or more recesses.

[0012] With regard to the opposite section, it has proven advantageous for it to have a channel lip. A channel lip extends in or parallel to the flow direction and can therefore perform a certain flow-guiding function. However, such a channel lip advantageously does not have a sealing effect. Several channel lips can be arranged side by side, so that the medium can flow along the channel lips or between two channel lips in one direction. Two adjacent channel lips can be connected to each other via a connecting area, so that the medium also flows between the channel lips over the opposite section or the connecting area of ​​the opposite section. This ensures good stability and strength and eliminates the risk of channel lips becoming detached after prolonged use.

[0013] On the side of the channel lips opposite the support plate, they can abut a separating layer, so that the channel lips, together with the connection area between the channel lips and the separating layer arranged parallel to the connection area, can form an approximately rectangular flow channel. The channel lips can thus provide a spacing or support effect and ensure a constant distance between the support plate and the separating layer. Channel lips of different lengths can be provided. For example, longer and shorter channel lips can be arranged alternately next to each other.

[0014] If the opposing section with the channel lips is connected to a sealing section on the other side of the carrier plate, the channel lips and the sealing lip(s) can be aligned transversely to each other. This ensures that the medium cannot pass through the sealing lip on the sealing lip side, but can flow past it on the channel lip side. Thus, a sealing effect is achieved on one side, while on the other side only a flow-guiding and support effect is achieved.

[0015] Additionally or alternatively, the opposing section can also be designed as a spacer. The spacer can, but need not, provide a seal; it can also be designed so that the medium flows around it. The spacer can ensure a consistent distance between the carrier plate and the adjacent separating layer, which will be explained in more detail below with regard to the fuel cell. The separating layer can thus be arranged on the spacer, and the spacer can have a flattened surface, particularly oval or lenticular, which can serve as a bearing surface for the separating layer. Advantageously, several spacers are provided to maintain a consistent distance between the carrier plate and the separating layer over a larger area.The spacers can be connected to each other; however, it is advantageous if they are not connected in order to limit the free flow cross-section as little as possible. It can, however, be provided that each spacer is connected via one or more recesses to a continuous counterpart or sealing section on the other side of the support plate.

[0016] According to a further embodiment, the counter-section can also be designed as a retaining plate. In this embodiment, the counter-section's sole function is to positively connect the sealing section to the carrier plate. In this embodiment, the counter-section can be only slightly larger than the recess. This allows the counter-section to be pressed through the recess by elastic deformation, thus releasing the positive connection. The counter-section can therefore function as a kind of push button, allowing for a temporary connection of the sealing section. However, it is generally not necessary to remove the sealing section from the carrier plate, especially once the sealing assembly is installed or used in a fuel cell.The opposing section can thus be advantageously sufficiently stable so that no elastic deformation is possible, which would allow the sealing section to be removed from the carrier plate without damage. In this design, the opposing section can have a smaller thickness than in the designs described above, so that the opposing section cannot come into contact with the separating layer arranged on the respective side of the carrier plate.

[0017] To achieve a connection, especially between larger sealing sections, it has proven advantageous to provide multiple recesses. This design allows the sealing section and its counterpart to be connected at several points. Consequently, the sealing section and its counterpart can penetrate the carrier plate at multiple locations. This enables a reliable connection across a larger area and through multiple recesses. It is advantageous for the recesses to be arranged in a row. This row of recesses can extend primarily perpendicular to the flow direction of the medium. Furthermore, several rows of recesses can be arranged side by side, resulting in a matrix-like arrangement of the recesses.This allows the reliable connection between the sealing section and the mating section to be extended over a larger area. In practice, two adjacent rows of recesses have proven particularly advantageous. This is because the sealing section can be designed in a strip shape and then reliably connected to the carrier plate via the two rows of recesses. The two rows can be arranged parallel to each other, and the recesses can be spaced at a constant distance.

[0018] The recess can advantageously have a circular cross-section, and therefore can be designed as a cylindrical bore. This reliably avoids stress concentrations and notch effects that could otherwise occur at corners. If several recesses are provided, they can all have the same cross-section or geometry, which has proven advantageous in terms of manufacturing. However, differently shaped recesses are also possible.

[0019] With regard to the sealing section, it has proven advantageous for it to have at least one, preferably several, sealing lips. The sealing lip ensures a reliable seal, preventing the medium from flowing over the sealing lip or across a sealing line created by contact between the sealing lip and a separating layer. The sealing lip, and thus the sealing line, can therefore extend in the direction of flow or parallel to the flow direction. If the sealing section has multiple sealing lips, these can extend parallel to each other, thereby increasing the overall sealing effect. The multiple sealing lips can be arranged side by side, creating an even more reliable seal in a series configuration. The sealing lip, or...The sealing lips can be designed as wave crests, so that with several sealing lips arranged side by side, multiple wave crests and troughs are positioned next to each other. It is possible for the sealing lips to have the same contour and height, but it is also possible to use sealing lips of different heights. The sealing lips can be integrally connected, for example, via wave troughs arranged between each pair of sealing lips.

[0020] The recesses can be arranged laterally to the sealing lips and, in particular, can run parallel to each other in two rows. This ensures a reliable connection and prevents the sealing lips from moving relative to each other. The sealing section can have a lateral projection and be connected in this projection area to the corresponding section located on the other side of the carrier plate via a recess. Multiple corresponding projection areas on opposite sides of the sealing lips are also possible. The projection area(s) can extend along the surface of the carrier plate. Because of the projection areas, it is not necessary for the sealing lips to be located within the area of ​​the recesses; rather, the recesses can be positioned away from the sealing lips and thus connected to them via the projection areas.The projecting areas and the sealing lips can be integrally connected, or the projecting area(s) can be an integral part of the sealing section. Alternatively, or additionally, recesses can be arranged between two sealing lips.

[0021] Furthermore, it has proven advantageous to arrange the sealing lips in such a way that two different media are separated from each other by a single sealing lip. This design reliably prevents the media from mixing. For example, it could sometimes happen that a medium, at least to a small extent, could pass from one side of the carrier plate to the other in the area of ​​a recess, especially if there is a relatively high pressure difference between the two sides of the carrier plate. The sealing lips are therefore advantageously positioned so that mixing of the media always requires a medium to pass through a sealing lip. In this way, even very small leakage flows and unwanted mixing of the media can be prevented. In the simplest case, this can be achieved by arranging the recesses in the area between two sealing lips.

[0022] Furthermore, it has proven advantageous to connect the multiple sealing lips via stabilizing ribs. Especially in the area of ​​the wave troughs, i.e., essentially between two sealing lips, the material of the sealing section can become very thin, sometimes only a few tenths of a millimeter thick. In addition, tensile stresses can occur in the material, particularly in the area between two recesses. These tensile stresses could lead to damage to the sealing section or the thin wave troughs. The stabilizing ribs, on the other hand, can provide additional stability precisely in this area. The stabilizing ribs can extend from one wave crest to an adjacent wave crest, thus reducing the risk of cracking at specific points where higher stresses are expected, thanks to the additional material. With several sealing lips arranged side by side, or...Stabilizing ribs can connect two adjacent wave crests at wave troughs and crests. However, in areas where no or only minimal tensile stresses are expected, i.e., away from the force flow from one recess to another, stabilizing ribs are not required. Therefore, the stabilizing ribs can be relatively short and do not fill the entire wave troughs.

[0023] Furthermore, it has proven advantageous for the sealing section to have a vent. When injection molding the sealing section, it is necessary that the injection material is evenly distributed in the injection mold on the corresponding side of the carrier plate. For this to happen, the air contained in the injection mold must be able to escape so that the mold can be completely filled with material. The injection mold should therefore have corresponding channels for this purpose. It can also be provided that the air is actively extracted at the ends of these channels to improve the distribution of the material in the injection mold. Especially when the injection mold is filled at different points, or when the sealing section is injection molded at different points, it is advantageous to have channels, particularly in the area between these two or more injection points, through which the air can escape or be drawn in.Venting vents can form as the material flows into the corresponding channels. These venting vents can be removed after curing and removal of the injection mold. Furthermore, the opposite side can also have one or more injection vents, which can be designed accordingly. It is also possible to provide recesses between the injection vents, allowing the vents on opposite sides of the carrier plate to be connected.

[0024] According to a structurally advantageous embodiment of the invention, the carrier plate has several protrusions that act as spacers. These protrusions can be arranged at regular intervals, thus ensuring a distance between an adjacent plate, membrane, or separating layer that is as constant as possible across the entire carrier plate. The protrusion can have a hemispherical geometry and contact the adjacent separating layer at specific points. However, other geometries are also possible. From a manufacturing perspective, the protrusions can be introduced into the carrier plate, for example, by an embossing process. The protrusions can bulge the carrier plate in one direction. It is also possible to have several protrusions, some of which bulge the carrier plate in one direction and others in the opposite direction.Therefore, two separating layers arranged essentially parallel to the carrier plate can be kept at a constant distance. It is also possible for one or more separating layers to have corresponding bulges. In this case, adjacent plates can essentially keep each other at a distance.

[0025] From a design perspective, it has proven advantageous for the opposing section to have increased thickness in the area of ​​a recess. This increased thickness enhances stability, particularly in the critical area of ​​the recess, thus reducing the risk of the opposing section shearing off the recess or the material penetrating it. Consequently, more material can be available in the recess area than elsewhere. The increased thickness can be located at the end of a channel lip. The sealing section can also be equipped with a corresponding increased thickness.

[0026] With regard to the aforementioned task, a fuel cell with a sealing arrangement is further proposed, wherein the sealing arrangement is designed in the manner described above.

[0027] Furthermore, the fuel cell has at least one separating layer extending at least substantially parallel to the carrier plate, with the sealing section making sealing contact with the separating layer. A medium can thus flow between the carrier plate and the separating layer, and the sealing section can ensure that the medium flows only in a predetermined direction and, in particular, cannot leave the flow area between the carrier plate and the separating layer. The separating layer and the carrier plate can have substantially identical geometries and maintain a distance from each other that is at least approximately constant across the entire plate surface. This distance can be determined by the height of the sealing arrangement or by the height of the sealing section and / or the mating section.

[0028] Another separating layer can also be provided on the other side of the support plate, which can be designed and arranged analogously to the separating layer described above. This separating layer(s) can be another support plate. The use of bipolar plates, sieve plates, or perforated plates is also possible. Furthermore, the separating layer(s) can also be a membrane, in particular a subgasket. Therefore, the fuel cell as a whole can have a layered structure, and several layers can be arranged one above the other, with two adjacent layers forming a flow channel.

[0029] Furthermore, it may be provided that the sealing section and / or the counter section is in contact with an adjacent separating layer. However, it may also be provided that the sealing section and / or the counter section is in contact with sealing sections and / or counter sections of an adjacent carrier plate or an adjacent separating layer.

[0030] The term "fuel cell" encompasses not only cells that generate electrical energy through the conversion of fuel, but also cells that use electric current to bring about a material conversion. These are referred to as reversible fuel cells or electrolyzers and are included in claim 1.

[0031] With regard to the aforementioned problem, a method for manufacturing a sealing arrangement for a fuel cell is further proposed. The sealing arrangement is advantageously designed in the manner described above. That is to say, a sealing arrangement of the type described above can be manufactured using the method. In this respect, reference is also made to the preceding explanations concerning the fuel cell and the sealing arrangement. The method is characterized by the following steps:

[0032] Provide a support plate;

[0033] Providing at least one recess in the carrier plate, wherein the recess extends from one side of the carrier plate to the other side of the carrier plate and thus penetrates the carrier plate; applying a sealing section to one side of the carrier plate;

[0034] Applying a counter-section to the opposite side of the carrier plate;

[0035] Connecting the sealing section and the opposing section through the recess to create a positive-locking connection with the carrier plate.

[0036] Regarding the process, it has proven advantageous to injection-mold the sealing section onto one side of the carrier plate and the counter-section onto the other. The sealing section and the counter-section, or the liquid materials during injection, can flow into one another through the recess and bond together, so that after curing, the sealing section and the counter-section are integrally joined. A clear separation between the material of the sealing section and the material of the counter-section is then no longer discernible. Before injection-molding the sealing section and the counter-section, appropriate injection molds can be applied to the carrier plate, into which the material forming the sealing section and the counter-section can be injected.After curing, the molds can be removed, and the sealing section and the mating section are then permanently bonded to the carrier plate. Permanently bonded means that the elements can no longer be separated from each other without damage. Alternatively, it is also conceivable to create a separable connection, for example, if the mating section is only slightly larger than the recess. By elastically deforming the mating section to the size of the recess, the sealing section can then be removed from the carrier plate. Alternatively, it can also be provided that injection occurs only from a single side. The material can then flow from one side through the recess to the other. This is particularly possible if the mating section is to be very small and, for example, no additional sealing or support function is required.

[0037] Further details and advantages of the invention will be explained in more detail below with reference to the accompanying drawings. These show:

[0038] Fig. 1 shows a top view of a support plate of a fuel cell including a detail view;

[0039] Fig. 2a a perspective detail view of the support plate with a sealing section and a counter section;

[0040] Fig. 2b shows a perspective sectional view of the back of the support plate according to Fig. 2a;

[0041] Fig. 3a a perspective sectional view of a support plate;

[0042] Fig. 3b shows an enlarged perspective sectional view of a support plate according to Fig. 3a with a different section plane;

[0043] Fig. 4 shows a cutaway side view of a carrier plate with a sealing section and a counter section;

[0044] Fig. 5 shows a fuel cell consisting of several layers;

[0045] Fig. 6 shows a perspective sectional view of a carrier plate with a sealing section and a counter section according to a first embodiment;

[0046] Fig. 7 is a perspective sectional view of a carrier plate with a sealing section and a counter-section according to a second embodiment; Fig. 8 is a perspective sectional view of a carrier plate with a sealing section and a counter-section according to a third embodiment;

[0047] Fig. 9 shows a perspective sectional view of a carrier plate with a sealing section and a counter section according to a fourth embodiment;

[0048] Fig. 10 shows a perspective sectional view of a carrier plate with a sealing section and a counter section as well as a separating layer;

[0049] Fig. 11 shows a perspective sectional view of a carrier plate with a sealing section and a counter section as well as a separating layer according to another embodiment;

[0050] Fig. 12 shows a perspective sectional view of a carrier plate with a sealing section, a counter section and a vent flap;

[0051] Fig. 13 shows a perspective sectional view of a carrier plate with a sealing section and a counter section, wherein the counter section is designed as a spacer;

[0052] Fig. 14 shows a perspective sectional view of a support plate with a sealing section, a counter section and several stabilizing ribs.

[0053] The figures show a sealing arrangement 10, which can be used, for example, in a fuel cell 20. The sealing arrangement 10 essentially consists of a carrier plate 1, on one side 1.2 of which a sealing section 2 and on the other side a counter-section 3 are arranged. The carrier plate 1 has several cylindrical recesses 1.3 that extend from the first side 1.1 to the second side 1.2 and through which the sealing section 2 and the counter-section 3 are integrally connected. Thus, the sealing section 2 and the counter-section 3 extend through the recesses 1.3 and the carrier plate 1, respectively, so that they are positively connected to the carrier plate 1.

[0054] First, various concepts according to the invention will be described with reference to the illustrations in Figs. 6 to 14, before the design of a fuel cell 20 is described in detail with reference to the illustrations in Figs. 1 to 5, in which these concepts can be used individually or in combination.

[0055] Figure 6 shows a carrier plate 1, on each of its two sides 1.1, 1.2, a sealing section 2 is arranged. The opposing section 3 is also designed as a sealing section 2. Two rows of circular recesses 1.3 extend along the carrier plate 1 and penetrate it. The two sealing sections 2 are connected to each other via these recesses 1.3, resulting in a positive-locking connection between both sealing sections 2 and the carrier plate 1. Centrally located between the two rows of recesses 1.3, each of the two sealing sections 2 has a sealing lip 2.1, so that the two sealing lips 2.1 are opposite each other with respect to the plane of the plate. The two sealing sections 2 are thus essentially identical.

[0056] Not shown in the illustration are separating layers 4, which can also be designed as plates and are arranged parallel to each other on the opposite side of the depicted support plate 1. The area between the support plate 1 and each separating layer 4 thus acts as a flow channel, and a medium can flow along the sealing lips 2.1 between the two plates. Overflow via the sealing lip 2.1 is not possible, since each sealing lip 2.1 makes sealing contact with a separating layer 4, resulting in a straight sealing line D on both sides 1.1, 1.2 of the support plate 1, which is aligned parallel to the flow direction.

[0057] As can be further seen, the two sealing sections 2 are each connected to each other at their edges via the recesses 1.3. The areas of the sealing sections 2 extending along both sides 1.1, 1.2 of the carrier plate 1 from the sealing lip 2.1 to the recess 1.3 are referred to as projection areas 2.3, and the media could flow over these projection areas 2.3.

[0058] In this configuration, the media on sides 1.1 and 1.2 of the carrier plate 1 cannot mix due to the sealing lip 2.1. However, there is a risk of leakage through the recess 1.3. For example, a medium from above the carrier plate 1 could then flow through the recess 1.3 into the area below the carrier plate 1. This potential problem can be prevented by the configurations shown in Figures 7 and 8.

[0059] The embodiment shown in Fig. 7 illustrates that the two sealing sections 2 each have two sealing lips 2.1, which are arranged in a way that prevents a medium from penetrating the area between the two sealing lips 2.1, at least as long as the sealing lips 2.1 provide a sufficient seal. Furthermore, it can be seen that a series of recesses 1.3 are now provided in this area between the sealing lips 2.1, so that there is no longer a risk of the media reaching the other side 1.1, 1.2 of the carrier plate 1 via the recesses 1.3 in this area. However, the right-hand area in the embodiment according to Fig. 7 is identical to the embodiment according to Fig. 6, so that a corresponding risk of leakage still exists here. This embodiment can therefore be used, for example, when the right-hand side of the two sealing lips 2...1. Different media flow above and below the support plate 1, but on the left side of the two sealing lips 2.1, the same media are present on both sides of the support plate, or the same pressure conditions prevail, so that leakage is less critical here. In the embodiment according to Fig. 8, this area and the corresponding recesses 1.3 have now been removed. The two sealing sections 2 are now only connected to each other via a single row of recesses 1.3, but the arrangement of the recesses 1.3 between the two sealing lips 2.1 ensures that no unintentional leakage flow from one side 1.1 of the support plate 1 to the other side 1.2 of the support plate 1 can occur through the recesses 1.3. This embodiment can therefore be used when different media are present to the left and right of the sealing lips 2.1 as well as above and below the support plate 1.

[0060] In both the embodiment shown in Figures 7 and 8, a different medium can flow between the two sealing lips 2.1 than in the area outside the sealing lips 2.1. No leakage can occur in this area either. Overall, the sealing lips 2.1 in the various embodiments are designed and arranged such that at least one sealing lip 2.1 is present between two different media or between two media where leakage must be prevented in any case. This means that if the leakage flow passing through a recess 1.3 does not have to pass through a sealing lip 2.1, leakage may occur.

[0061] In the embodiment according to Fig. 7, for example, no sealing lip 2.1 is provided to the left of the sealing lip 2.1 between the medium flowing above and below the support plate 1. This allows the same media to be used above and below the support plate 1, thus making leakage less critical. In the embodiment according to Fig. 8, the leakage flow would necessarily have to pass through a sealing lip 2.1 in order to flow, for example, on the upper side of the support plate 1 under the sealing section 2 to the recess 1.3. This is reliably prevented by the sealing lip 2.1 and the contact force exerted by the sealing lip 2.1 on the support plate 1. It is therefore possible for a different medium with a different pressure to be in contact with each sealing lip 2.1 without leakage occurring.

[0062] The embodiment shown in Fig. 9 differs from the examples shown in Figs. 6, 7, and 8 in that the counterpart section 3 is not designed as a sealing section 2. It therefore does not have a sealing lip 2.1, but merely serves to fix the sealing section 2 to the upper side 1.1 of the carrier plate 1. In this embodiment, the counterpart section 3 thus only has the form of a retaining plate, and the individual retaining plates on the lower side 1.2 of the carrier plate 1 do not necessarily have to be connected to each other. The retaining plates can be mechanically separated. If there is no adhesion between the carrier plate 1 and the sealing lip 2.1, a laser contour for connecting or sealing the carrier plate 2 transversely to the sealing lip 2.1 can be introduced by folding back the sealing lip 2.1 at that point, and then the sealing lip 2.1 can be repositioned.1 are reconnected to the carrier plate 1 via the retaining plates.

[0063] On the upper surface 1.1 of the carrier plate 1, it can be seen that the sealing section 2 is designed differently on opposite sides of the sealing lip 2.1. On the right side, narrow projection areas 2.3 extend parallel to each other to the recesses 1.3, without adjacent projection areas 2.3 being connected to one another. On the other side, however, a more planar and continuous projection area 2.3 is provided. This projection area 2.3 may therefore lead to greater stability; however, the material requirement is also lower compared to the separate and rib-like projection areas 2.3 on the other side of the sealing lip 2.1.

[0064] It should also be noted that the recesses 1.3 are shown partially filled and partially unfilled. This can be seen, for example, in the illustration in Fig. 9. However, since the two opposing sealing / counter sections 2, 3 are integrally connected to each other via the recesses 1.3, the corresponding material of the sealing / counter sections 2, 3 completely fills the recesses 1.3. That is, the recesses 1.3 are entirely filled with material to ensure a positive-locking connection with the carrier plate 1.

[0065] Figure 10 shows a somewhat more complex embodiment. First, a support plate 1 is again provided, which is equipped with a sealing section 2 and a counter-section 3, as already described with reference to Figure 9. Furthermore, the support plate 1 has several protrusions 1.4 arranged in a row and essentially parallel to the recesses 1.3 to the left and right of the sealing section 1.1. These protrusions ensure a constant distance between the upper support plate 1 and the separating layer 4, which is also designed as a support plate 1 and is located below it. The protrusions 1.4 have a substantially semicircular shape and contact the lower support plate 1 at their underside, so that the two support plates 1 maintain an approximately constant distance across the entire surface of the plate and are thus arranged essentially parallel to each other.

[0066] The lower support plate 1 is also provided with a sealing section 2 and a counter-section 3, which are positively connected to the support plate 1 via recesses 1.3, as explained above. In contrast to the upper support plate 1, however, the lower support plate 1 only has one row of recesses 1.3, so that the sealing section 2 is only connected to the opposite counter-section 3 on one side of the sealing lip 2.1. As can be further seen, the two counter-sections 3 abut each other in the space between the two support plates 1 and can thus potentially achieve a slight sealing effect, even though no sealing lip 2.1 is provided in this area.

[0067] To the right of the bulges 1.4, the two support plates 1 form an approximately circular flow channel. This is created because the upper support plate 1 is curved upwards in a cylindrical shape, essentially parallel to the sealing lip 2.1, while the lower support plate 1 is curved downwards in the opposite direction. Analogous to the semicircular bulges 1.4, these channel-shaped bulges also allow for a constant distance to other separating layers 4, which can be located above the upper support plate 1 or below the lower support plate 1. Further to the right of the channel-shaped bulges, it can be seen that the two support plates 1 are welded together via an optional weld. This weld provides a reliable connection between the two support plates 1, and they cannot be separated from each other after welding.The weld seam can also be used to separate different media from each other.

[0068] The embodiment shown in Fig. 11 essentially corresponds to the embodiment shown in Fig. 10. The main difference is that the sealing sections 2 and the opposing sections 3 of the two support plates 1 are now identically designed. That is, the upper support plate 1 now also has only one series of recesses 1.3, and accordingly, a projection area 2.3 is provided only on one side of the sealing lip 2.1, extending to the recesses 1.3 and thus allowing a connection with the opposite opposing section 3.

[0069] In the embodiment according to Fig. 10, it can be provided that in the area between the two support plates to the left of the two sealing lips 2.1, the same medium flows both above and below the two support plates 1 and to the right of the upper sealing lip 2.1. However, it may also be provided that the medium is partially under different pressures, e.g., to the left and right of the sealing lip 2.1.

[0070] 2.1 However, a different medium can flow through the lower support plate 1. This is because it is sealed via a sealing lip.

[0071] 2.1 separated from the first-mentioned medium.

[0072] In the embodiment according to Fig. 11, the area is above the upper support plate 1 and to the right of the sealing lip.

[0073] 2.1 is separated from the area between the support plates 1 by a sealing lip 2.1. Thus, a first medium can flow to the right of the two sealing lips 2.1 above and below the support plate 1, as well as between the two support plates 1, while a different medium can flow to the right of the sealing lips 2.1 below the lower and above the upper support plate 1. This configuration therefore allows three media flows to be reliably separated from each other.

[0074] Overall, the concepts explained with reference to Figures 6 to 11 can be combined with one another in any way, so that the above explanations are not to be understood as limiting to a single embodiment. Further fundamental aspects of the present invention, which can also be combined with the concepts and embodiments described above, will now be explained with reference to Figures 12 to 14.

[0075] Figure 12 shows a carrier plate 1 with two sealing sections 2 arranged on opposite sides 1.1, 1.2 of the carrier plate 1 and connected to each other in the manner described above. Also visible are so-called venting tabs 2.5, which are of little use in the context of the use of the sealing arrangement 10, but which may be important for the manufacturing process. In all embodiments, the sealing sections 2, or the sealing section 2 and the opposing section 3, consist of the same material, namely an elastomer. To manufacture the sealing arrangements 10, a carrier plate 1 is first provided, and then the sealing section 2 and the opposing section 3 are injection-molded onto the two opposite sides 1.1, 1.2 of the carrier plate 1. For this purpose, the carrier plate 1 is cut on both sides 1.1, 1.2.2 is provided with a mold into which the liquid material, forming the sealing section 2 and the counter section 3, is injected. This is also referred to as the material being injected onto the carrier plate 1.

[0076] Since the mold initially contains air, which is then replaced by the material, the air must be vented from the mold. This is done via small channels, which are arranged particularly in areas where air venting is most beneficial. For example, if the upper side 1.1 of the carrier plate 1 is injection-molded at two points, meaning the material flows towards each other from opposite directions, a corresponding channel is provided in the central area from which the air can escape. Advantageously, several channels are provided in this area so that the air can be reliably vented and no air pockets form. Of course, the material also flows into these channels and then hardens within them. These areas can be seen in Fig. 12 as venting channels 2.5.This is therefore excess material that was no longer required for the production of sealing section 2 or the opposing section 3. The venting tabs 2.5 can be removed after production, although they may remain in some areas.

[0077] During injection molding, the liquid material can also flow into the recesses 1.3 of the carrier plate 1, which connect the two sides 1.1 and 1.2 of the carrier plate 1. The material can thus fill the recesses 1.3, and once the material has cured, the sealing section 2 and the opposing section 3 are integrally bonded, and there is no longer an interface between the sealing section 2 and the opposing section 3. Small recesses 1.3 extending through the carrier plate 1 can also be provided in the area of ​​the channels described above or in the corresponding area of ​​the vent flaps 2.5. In this respect, the sealing section 2 and the opposing section 3 can also be connected in this area. If additional recesses 1.3 are provided in the area of ​​the vent flaps 2.5, it is naturally advantageous not to remove these vent flaps 2.5.

[0078] Figure 13 shows a carrier plate 1, on the underside 1.2 of which a sealing section 2 with three adjacent sealing lips 2.1 is arranged. It can be seen that the sealing lips 2.1 do not all have the same height; the middle sealing lip 2.1 is higher than the two side sealing lips 2.1. On the upper side 1.1 of the carrier plate 1, the opposing sections 3 are each connected to the sealing section 2 via two recesses 1.3. The opposing sections 3 are not connected to each other on the upper side 1.1 of the carrier plate 1, but rather are spaced apart from each other. Therefore, the opposing sections 3 cannot create a sealing effect on the corresponding side of the carrier plate 1; instead, the medium can flow around the opposing sections 3. A sealing effect with regard to the recesses 1.3 is therefore not possible.However, the separation layer 4, arranged above the illustrated support plate 1 (but not shown), can be achieved by the opposing sections 3. In this embodiment, the opposing sections 3 primarily serve as spacers to maintain a constant distance between the separation layer 4 and the support plate 1. As shown in Fig. 13, the separation layer 4 then rests on top of the oval bearing surfaces of the opposing sections 3.

[0079] Figure 14 shows a carrier plate 1 with a sealing section 2 arranged on the upper surface 1.1 of the carrier plate 1, which has several sealing lips 2.1 arranged side by side. On the lower surface 1.2, the corresponding section 3 is also designed as a sealing section 2 and, analogous to the embodiment shown in Figure 13, has three sealing lips 2.1 of different heights arranged side by side. The sealing lips 2.1 arranged on the upper surface 1.1 are designed as wave crests, and a wave trough is provided between each pair of adjacent wave crests. In the area of ​​the wave troughs, the sealing section 2 is therefore very thin overall. For this reason, there is a risk of cracking or damage, particularly in the area of ​​the wave troughs between two recesses 1.3. As can be visualized with reference to Figure 14, part of the force flow runs from a recess 1.3 of a row to a recess 1.3 of the other row. That is, part of the force flow runs transversely to the longitudinal direction of the sealing lips 2.1 or transversely to the sealing line(s) D.

[0080] To achieve a certain degree of reinforcement in this area, the sealing lips 2.1 are connected to each other via stabilizing ribs 2.2. The stabilizing ribs 2.2 extend from one sealing lip 2.1 to the adjacent sealing lip 2.1 transversely to the longitudinal direction of the sealing lips 2.1. This provides more material in the area between the sealing lips 2.1, reducing the risk of cracking, particularly in the area of ​​force flow between two opposing recesses 1.3. Away from the recesses 1.3, i.e., outside the force flow transverse to the longitudinal direction of the sealing lips 2.1, the acting forces are lower, so that the corrugations do not require additional reinforcement in this area. These stabilizing ribs 2.2 can also advantageously ensure that the sealing lips 2.1 remain on the carrier plate 1 during demolding from the injection mold and are not pulled off. Therefore, the stabilizing ribs 2.2. It may also be advantageous to insert it between the recesses 1.3.

[0081] Figure 1 shows a fuel cell 20, or rather one plate of a fuel cell 20 consisting of several plates arranged one above the other, in a top view. In the lower section, two inlets 21, designed as elongated holes, are provided through which a medium can flow perpendicular to the plane of the drawing. The medium is deflected, flows via the opposite section 3 (which will be explained in more detail below) into the reaction area 23, as indicated by the black arrows, and a portion then flows to the outlets 22 located opposite the inlets 21. Further inlets and outlets can be seen to the left and right, but these do not open into the plane shown, but rather into a different plane. Therefore, the medium flowing in these channels passes the depicted plate perpendicular to the plane of the drawing.

[0082] To ensure that the medium flows into the reaction zone 23 in the depicted plane in a predetermined manner and that leaks or inflow into undesired areas do not occur, the corresponding flow zone is sealed by a circumferential sealing section 2. The sealing section 2, visible in the detail of Fig. 1, thus extends around the lateral inlets / outlets and around the entire flow zone of the depicted plate, so that the medium can only flow in the manner described above.

[0083] In the area between the inlets 21 and the reaction zone 23, as well as between the reaction zone 23 and the outlets 22, there is no sealing section 2, but rather a counter-section 3, which allows a flow of medium to and from the reaction zone 23. This counter-section 3 has several channel lips 3.1 oriented in the direction of flow, which primarily provide a bearing surface for the separating layer 4 arranged above the support plate 1 shown. The medium can thus flow between the support plate 1 and the separating layer 4 arranged above it, between the channel lips 3.1, into the reaction zone 23. The outlet side is designed accordingly so that the medium can flow from the reaction zone 23 to the outlets 22.

[0084] Figure 2a shows a perspective view of the detail area shown in Figure 1, and Figure 2b shows the rear or underside of this area. It can be seen that the medium can flow in the direction of the black arrows over the opposite section 3, or over the connecting sections 3.2 that link the channel lips 3.1, and between the channel lips 3.1. The connecting sections 3.2 are lower than the channel lips 3.1, thus providing a sufficient free flow cross-section and ensuring sufficient stability over the connecting sections 3.2 and the resulting one-piece design of the opposite section 3. The opposite section 3 is located on side 1.1 of the support plate 1, and a sealing section 2 is provided on the opposite side 1.2, which has several sealing lips 2.1 arranged side by side. On the sealing lips 2.1 is arranged a separating layer 4 which is not shown in the illustrations of Fig. 2a and 2b, so that the medium cannot flow over the sealing lips 2.1.

[0085] In the sectional view of Fig. 2b it can also be seen that the carrier plate 1 has recesses 1.3 arranged in pairs, through which the sealing section 2 is connected to the opposing section 3, as explained above with reference to Figs. 6 to 14.

[0086] Furthermore, Figure 2a shows two essentially cuboid injection points 2.4, one belonging to the sealing section 2 and the other to the opposing section 3. These injection points 2.4 are created during manufacturing because the liquid material is injected into the injection molds at these locations. Similar to the venting flaps 2.5, this area can remain on the carrier plate 1 after the material has hardened, or alternatively, it can be removed.

[0087] As can be seen when comparing the illustrations in Figures 2a and 2b, the recesses 1.3 on the side of the opposing section 3 are arranged in the area of ​​the channel lips 3.1, whereas in the area of ​​the opposite sealing section 2, the several sealing lips 2.1 arranged side by side and extending transversely to the channel lips 3.1 do not extend into the area of ​​the recesses 1.3. Rather, it can be seen that flat projection areas 2.3 are provided laterally next to the sealing lips 2.1 and extend in every direction on the corresponding side 1.2 of the carrier plate 1, in which the sealing section 2 is then connected to the opposing section 3 via the recesses 1.3. The sealing lips 2.1 are thus not arranged directly in the area of ​​the recesses 1.3, but are connected to the recesses 1.3 via the projection areas 2.3. This can also be seen, for example, in the illustration in Figure 2a.1 and, in particular, can be seen from the enlarged detail view in Fig. 1, since the sealing lips 2.1 do not extend to the edge of the respective sealing section 2. Sufficient stability can be ensured by the lateral projection areas 2.3, as the force flow from two recesses 1.3 arranged in a row one behind the other thus only passes through the flat projection areas 2.3, which have a constant height, and not through the less resilient sealing lips 2.1. In combination with the stabilizing ribs 2.2 described above, which are not shown in Fig. 2b, a stable cross-band is thus formed between the individual recesses 1.3, in which the opposing recesses 1.3 are connected to each other via the stabilizing ribs 2.2 and the recesses 1.3 arranged one behind the other are connected to each other via the projection areas 2.3.Therefore, there is no risk of cracks occurring, especially in the areas between two recesses 1.3 that are often subjected to tensile stress.

[0088] Figure 3a shows a perspective view of the carrier plate 1 according to Figure 1. Visible is the counter section 3 located on side 1.1 of the carrier plate 1 between the reaction zone 23 and the outlet 22, with its several channel lips 3.1, which primarily function as spacers and are oriented in the flow direction, as well as a sealing section 2 that is integrally connected laterally to the counter section 3 and branches out closely. It can also be seen that the sealing section 2 has three sealing lips 2.1 arranged side by side, whereas the sealing section 2 located on the underside 1.2 of the carrier plate 1 has significantly more sealing lips 2.1 arranged side by side. The two sealing sections 2, i.e., the sealing section 2 located on side 1.1 and the sealing section 2 located on side 1.2, thus differ from each other with respect to the number of sealing lips 2.1.1 and, consequently, the sealing lines D of the two sealing sections 2 run parallel to each other in the same direction. Furthermore, the multiple injection points 2.4 in the area of ​​sealing section 2 and the injection points 2.4 in the area of ​​the opposing section 3 are also visible.

[0089] Figure 3b shows, analogously to the view in Figure 2b, a section through the carrier plate 1, which also reveals the recesses 1.3. The two upper recesses 1.3 on the left serve to connect the opposing section 3 with the sealing section 2, as explained above, and the upper right recess 1.3 serves to connect two sealing sections 2. Figure 3a shows that a sealing section 2 is integrally connected to the opposing section 3 on the right, and is thus connected to the sealing section 2 of the underside 1.2 of the carrier plate 1 via the recess 1.3 before the branching point. The three lower recesses 1.3 are each arranged concentrically to the three upper recesses 1.3 and serve to connect a separating layer 4 arranged parallel to the carrier plate 1.First, a separating layer 4, designed as a membrane, is provided below the sealing section 2 of the upper support plate 1. This separating layer is in sealing contact on its upper side with the sealing section 2 located on the underside 1.2 of the upper support plate 1. On the other side of the membrane-designed separating layer 4, another sealing section 2 is provided, which has three adjacent sealing lips 2.1 and is designed in the same way as the sealing section 2 visible on the upper side 1.1 of the upper support plate 1. This sealing section 2 is in turn arranged on a separating layer 4, which is designed as a support plate 1 and is arranged parallel to the upper support plate 1. On the underside 1.2 of this support plate 1, yet another sealing section 2 is arranged, which also has three adjacent sealing lips 2.1.These different layers can also be seen in the sectional view of Fig. 3a.

[0090] Figure 4 shows a longitudinal section through the carrier plate 1, revealing the channel lips 3.1 in cross-section. On the opposite side 1.2, the sealing section 2 and a sealing lip 2.1 are visible. The layer visible between the sealing lip 2.1 and the underside 1.2 of the carrier plate 1 corresponds to the projection area 2.3, via which the sealing lips 2.1 are connected to the recess 1.3, as explained above.

[0091] The cross-sectional view also shows that the opposing section 3 has a thickness reinforcement 2.6 in the area of ​​the recess 1.3, i.e., in the extension of the recess 1.3. In the area of ​​this thickness reinforcement 2.6, slightly more material is available. Thus, the strength is increased in this area, and the positions of the recesses 1.3 can still be seen from the outside even after injection molding. The area between the channel lips 3.1 serves as a flow channel, which is formed downwards by the connection area 3.2 of the opposing section 3 between two channel lips 3.1. The channel is bounded upwards by the separating layer 4, which rests on the channel lips 3.1 but is not shown in Fig. 5a and is arranged essentially parallel to the carrier plate 1.

[0092] Figure 5 shows a fuel cell 20, consisting of several layers, in a perspective side view. The inlets and outlets for the various media, also shown in Figure 1, are visible at the edges. The upper and lower plates of the fuel cell 20, or the stack shown, are bipolar plates, and two support plates 1 with sealing devices 10 are arranged between the two bipolar plates, as described above. A membrane is provided between the two support plates 1, which is sealed on opposite sides by a sealing section 2. The connection between the sealing section 2 and the opposing section 3 described above ensures a reliable, positive-locking connection with the support plate 1 without the need for an adhesion promoter.

[0093] REFERENCE MARK LIST

[0094] 1 carrier plate

[0095] 1.1 Page

[0096] 1.2 Page

[0097] 1.3 Exclusion

[0098] 1.4 Bulge

[0099] 2 Sealing section

[0100] 2.1 Sealing lip

[0101] 2.2 Stabilizing rib

[0102] 2.3 Lead area

[0103] 2.4 Injection

[0104] 2.5 Venting plume

[0105] 2.6 Thickness reinforcement

[0106] 3 Opposite section

[0107] 3.1 Channel lip

[0108] 3.2 Connection area

[0109] 4 Separation layer

[0110] 10 Sealing arrangement

[0111] 20 Fuel cell

[0112] 21 Entrance

[0113] 22 outlet

[0114] 23 Reaction range

[0115] D sealing line

Claims

PATENT CLAIMS 1. Sealing arrangement for a fuel cell (20) with a carrier plate (1) and a on one side (1.1) a sealing section (2) arranged on the carrier plate (1) for limiting a medium flowing along the carrier plate (1), characterized in that a counter section (3) is arranged on the side (1.2) of the carrier plate (1) opposite the sealing section (2), wherein the carrier plate (1) has at least one recess (1.3) connecting one side (1.1) with the other side (1.2) and extending through the carrier plate (1), and wherein the sealing section (2) is connected to the counter section (3) through the recess (1.3) for a positive connection with the carrier plate (1).

2. Sealing arrangement according to claim 1, characterized in that the sealing section (2) and the counter section (3) are integrally connected.

3. Sealing arrangement according to one of claims 1 or 2, characterized in that the opposing section (3) is designed as a second sealing section (2).

4. Sealing arrangement according to one of the preceding claims, characterized in that the opposing section (3) has a channel lip (3.1).

5. Sealing arrangement according to one of the preceding claims, characterized in that the opposing section (3) is designed as a spacer.

6. Sealing arrangement according to one of the preceding claims, characterized by several recesses (1.3), which are in particular arranged in a row.

7. Sealing arrangement according to one of the preceding claims, characterized in that the sealing section (2) has at least one, preferably several, sealing lips (2.1).

8. Sealing arrangement according to claim 7, characterized in that the multiple sealing lips (2.1) are connected to each other via stabilizing ribs (2.2).

9. Sealing arrangement according to one of claims 7 or 8, characterized in that the sealing lips (2.1) are arranged such that two different media are separated from each other by at least one sealing lip (2.1).

10. Sealing arrangement according to one of the preceding claims, characterized in that the sealing section (2) has a venting flap (2.5).

11. Sealing arrangement according to one of the preceding claims, characterized in that the carrier plate (1) has several protrusions (1.4) acting as spacers.

12. Sealing arrangement according to one of the preceding claims, characterized in that the opposing section (3) has a thickness reinforcement (2.6) in the area of ​​a recess (1.3).

13. Fuel cell with a sealing arrangement (10) according to one of the preceding claims and at least one separating layer (4) extending at least substantially parallel to the carrier plate (1), wherein the sealing section (2) makes sealing contact with the separating layer (4).

14. Method for manufacturing a sealing arrangement (10) for a fuel cell (20), comprising the following steps: Provide a support plate (1); Providing at least one recess (1.3) in the carrier plate (1), wherein the recess (1.3) extends from one side (1.1) of the carrier plate (1) to the other side (1.2) of the carrier plate (1) and thus extends through the carrier plate (1); Applying a sealing section (2) to one side (1.1) of the carrier plate (1); Applying a counter section (3) to the opposite side (1.2) of the carrier plate (1); connecting the sealing section (2) and the counter section (3) through the recess (1.3) to create a positive connection with the carrier plate (1).

15. Method according to claim 14, characterized in that the sealing section is injected onto one side (1.1) of the carrier plate (1) and the opposing section (3) is injected onto the other side (1.2) of the carrier plate (1).

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