Separation plate, bipolar plate, production method and electrochemical cell

Abstract

The invention relates to a separating plate (28) comprising: a half-sheet (3, 4) having an active zone (2); a frame means (11) surrounding the active region (2); and a sealing device (15, 15 ') assigned to the frame device (11) and comprising a seal (16, 16') extending in a wave shape in a top view of a plane spanned by the separating plate (28). A three-dimensional support structure (29) is formed in the half-sheet (3, 4) in the region of the sealing device (15, 15 '), the support structure (29) being formed so as to protrude from the plane spanned by the separator plate (28). The invention also relates to a bipolar plate (1, 1'), a method for producing a sealing device (15, 15 ') on a separator plate (28) or a bipolar plate (1, 1'), and an electrochemical cell (40).

Description

Field of the Invention

[0001] The present invention relates to a separator plate comprising: a half sheet having an active area; a frame device surrounding the active area; and a sealing device assigned to the frame device and comprising a seal which extends in a wave shape in a top view of the plane spanned by the separator plate. The present invention also relates to a bipolar plate comprising: a first half sheet and a second half sheet, each having an active area; a frame device surrounding the active area; and a sealing device assigned to the frame device and comprising a seal which extends in a wave shape in a top view of the plane spanned by the bipolar plate. The present invention also relates to a method for producing a sealing device on a separator plate or on a bipolar plate. Finally, the present invention relates to an electrochemical cell. Background Art

[0002] Separator plates or bipolar plates of the above type and electrochemical cells in the form of fuel cells are known from DE 10 2021 115 559 A1. The separator plate or bipolar plate has a sealing device which extends along the edge of the bipolar plate and surrounds the supply and discharge channels for fluids, here called ports, of the bipolar plate, and which is intended to seal the active area of the separator plate or bipolar plate relative to the environment. The sealing device comprises a seal which extends in a wave shape and is made of plastic. The permanent application of the sealing device to the respective half sheets of the separator plate or bipolar plate is carried out by means of an injection molding process. The separator plate or bipolar plate is inserted into an injection molding tool and the tool is closed. Since the geometry of the sealing device is usually formed according to the injection molding tool used, a high degree of dimensional accuracy and reproducibility can be achieved in the manufacture of the sealing device using the injection molding process.

[0003] However, it has been shown that when the injection molding tool is closed, due to the contact pressure of the sealing edge of the tool on the surface of the thin-walled separator plate or bipolar plate, deformations in the form of bulges of the half sheets can form in the cavities to be filled with injection molding material. The thin-walled separator plate comprises half sheets, and the bipolar plate comprises two half sheets firmly connected to each other. Cavities are formed on both sides of the separator plate or bipolar plate because the sealing device usually has to be formed on both sides.

[0004] The metal separator plate or bipolar plate has a half sheet with a sheet thickness typically in the range of less than 0.5 mm. With such a small sheet thickness, residual compressive stress will quickly cause unwanted deformation in the surrounding area. The smaller the sheet thickness of the half sheet used, the greater the effect. The cavity of the injection molding tool is slightly reduced at least on one side of the separator plate, but in the case of the bipolar plate, the cavity is slightly reduced on both sides of the bipolar plate, and the volume for injecting the injection molding material may thus also be reduced. If the injection molding compound is now injected into the injection molding tool, the following expected amount of injection molding material may not be introduced at least on one side of the plate: the expected amount of injection molding material for forming a sealing device with the required geometric dimensions.

[0005] After the injection molding material has cured and the injection molding tool has been opened, the previously deformed area of at least one half sheet will spring back to its original position. Since the injection molding material cannot be injected into the cavity of the injection molding tool, the sealing device does not exist in the required geometry or thickness on at least one half sheet or both half sheets now. After demolding and at least partial bulging back of one or both half sheets, the height of the seal deviates significantly from the tool dimensions. This deviation is particularly obvious in the straight sealing area. Depending on the sheet rolling direction, the surrounding stamping geometry or radius, or in the case of a curved sealing flange, the bulging effect will also occur to varying degrees. Summary of the Invention

[0006] The object of the present invention is to provide a separator plate including a half sheet or a bipolar plate including a first half sheet and a second half sheet, the separator plate or bipolar plate having a correctly and reproducibly dimensioned sealing device, which is injection molded on the separator plate or bipolar plate during the injection molding process. In addition, the object of the present invention is to provide a method suitable for this purpose and to provide an electrochemical cell.

[0007] For the separator plate, to achieve this object, the separator plate includes: a half sheet having an active area; a frame device surrounding the active area; and a sealing device assigned to the frame device and including a seal that extends in a wave shape in a top view of the plane spanned by the separator plate. This object is achieved by forming a three-dimensional support structure in the half sheet in the area of the sealing device, wherein the support structure is formed to protrude from the plane spanned by the separator plate.

[0008] For a bipolar plate, to achieve this object, the bipolar plate comprises: a first half-sheet and a second half-sheet, each of the first half-sheet and the second half-sheet having an active area; a frame device that surrounds the active area; and a sealing device that is assigned to the frame device and that includes a seal, the seal extending in a waveform shape in a top view of the plane spanned by the bipolar plate. This object is achieved in that a three-dimensional support structure is formed in the two half-sheets in the area of the sealing device, wherein the support structures of the two half-sheets are formed to project in opposite directions from the plane spanned by the bipolar plate and to be aligned one above the other when viewed perpendicular to said plane.

[0009] In the area of the active area of the separator or bipolar plate, an electrochemical reaction takes place in the electrochemical cell, in which the fluid supplied to the cell undergoes a chemical conversion.

[0010] By providing support structures in each half-sheet within the geometry of the sealing device, the deformation of the half-sheet or half-sheets in the injection molding tool can be greatly reduced, since this causes local hardening of the half-sheet, thus counteracting the deformation. The injection molding material flows around the support structures, embedding the support structures and providing additional mechanical stability to the separator or bipolar plate.

[0011] Preferably, when viewed in a cross-section through the separator or bipolar plate, the support structure has a conical or hemispherical or lenticular shape. Such support structures in the half-sheet or two half-sheets provide excellent local hardening of the half-sheet. In the case of a bipolar plate, the support structures can be particularly well aligned one above the other.

[0012] It has proven particularly effective for the three-dimensional support structures to be formed in the half-sheets in the area of the seal that extends in a waveform shape, and for one support structure to be formed in the half-sheet for each waveform structure of the seal that extends in a waveform shape. However, several support structures can also be provided for each waveform structure to further increase the stiffness of the half-sheet in this area.

[0013] The waveform seal preferably has a plurality of straight sections, by means of which a common first straight line is defined, wherein the straight sections are each connected to one another by a curved section. In this case, the maximum offset of each curved section of the seal with respect to the straight section, measured in a direction orthogonal to said first straight line, corresponds to at least twice and at most five times the width of the waveform seal, for example. This means that the extension length of the waveform seal is significantly increased compared to a conceivable straight sealing strip, without requiring much additional installation space.

[0014] In this embodiment, the minimum radius of curvature of the corrugated seal can in particular be greater than the width of the corrugated seal, but less than the said offset between the curved section and the straight section of the corrugated seal. In particular, the minimum radius of curvature is given at the transition between the straight section and the curved section of the corrugated seal.

[0015] Preferably, each support structure in the support structure is arranged on a straight line that intersects the straight section of the associated corrugated structure in a centered manner and at a 90° angle. The corrugated structure includes a straight section and two adjacent curved sections.

[0016] Preferably, the support structure in each half-sheet has the following height starting from the surface of the half-sheet: this height corresponds to the maximum thickness D ± 20% of the sealing device injection-molded onto the half-sheet. Thus, the height of the support structure is designed such that the support structure has a size that is slightly too small (-20%) to slightly too large (+20%) with respect to the cavity height of the cavity of the injection-molding tool for forming the sealing device, and the support structure can thus be supported on the inner part of the injection-molding tool. When the injection-molding tool is closed, the support structure inside the cavity formed between the surface of the separator plate or bipolar plate and the injection-molding tool contacts the injection-molding tool. Thus, the half-sheet is held in the desired position and any undesired deformation of the half-sheet is directly counteracted.

[0017] Such a support structure can be used in the main sealing strip or secondary sealing strip of the sealing device. The term secondary sealing strip particularly refers to a sealing section for containing a flow bypass near the active field, such as the corrugated seal of the sealing device here.

[0018] The separator plate is made of a molded half-sheet or a metal sheet and has embossed flow channels for guiding the flow of fluid on the anode and cathode sides, and the embossed flow channels are preferably aligned parallel to the straight section of the corrugated seal, particularly in the active area.

[0019] The bipolar plate is particularly made of two molded half-sheets and has embossed flow channels for guiding the flow of fluid on the anode and cathode sides, and the embossed flow channels are preferably aligned parallel to the straight section of the corrugated seal, particularly in the active area. For example, the half-sheets are connected to each other by a welded joint. However, the two half-sheets can also be glued or welded together. Preferably, a space through which the coolant can flow is formed between the molded half-sheets.

[0020] The half-sheets of the separator plate or bipolar plate preferably have a sheet thickness in the range of 50 µm to 200 µm, particularly in the range of 50 µm to 100 µm.

[0021] The separator plate or bipolar plate according to the invention is suitable for forming an electrochemical cell, in particular an electrochemical cell in the form of a polymer electrolyte fuel cell or a polymer electrolyte electrolyzer for water electrolysis or a redox flow battery.

[0022] For a method for producing a sealing device on a separator plate or a bipolar plate according to the invention, this object is achieved by the following steps:

[0023] - Inserting a half-sheet or two half-sheets firmly connected to each other into an injection molding tool, wherein a cavity for forming the sealing device is formed between the half-sheet and the injection molding tool, and a three-dimensional support structure is supported against the injection molding tool in the cavity,

[0024] - Injecting an injection molding material into the cavity, wherein the support structure is at least partially embedded in the injection molding material,

[0025] - Curing the injection molding material in the cavity, and

[0026] - Demolding the separator plate or bipolar plate with the formed sealing device attached.

[0027] Thus, the support structure acts as a spacer between the respective half-sheet and the injection molding tool and prevents warping of the half-sheet or half-sheets when the injection molding tool is closed. Additionally, the support structure is embedded in the sealing device, wherein only the region of the support structure that contacts the injection molding tool during the injection process can remain uncovered by the injection molding material. Thus, the support structure does not affect the sealing function of the sealing device. On the contrary, the support structure results in a higher dimensional accuracy of the sealing device and enables a more precise molding of the cavity of the injection molding tool with the injection molding material. As a result, a finely and precisely formed sealing device is injection-molded on one side or both sides of the half-sheets of the separator plate or a finely and precisely formed sealing device is injection-molded on each of the half-sheets of the bipolar plate half-sheets.

[0028] For an electrochemical cell, this object is achieved, the electrochemical cell comprising a plurality of separator plates or bipolar plates according to the invention and at least one membrane electrode assembly arranged between two separator plates or bipolar plates, the membrane electrode assembly having a central region near the active region and a region arranged outside the active region when viewed perpendicular to the plane spanned by the separator plate or bipolar plate, wherein a seal extending in a waveform shape is located at the boundary between the regions.

[0029] For example, the membrane electrode assembly can be configured as seven layers and generally includes a membrane, electrode layers applied on two sides of the membrane to form an anode and a cathode, catalyst layers applied on the two sides, and optionally porous fluid distribution layers arranged on the two sides. The membrane electrode assembly typically has a plastic support frame firmly attached to the edge region for reinforcement. Then, the electrode layers, catalyst layers, and fluid distribution layers are located within the plastic support frame, which encloses the corresponding active regions of the separator plate or bipolar plate adjacent to the membrane electrode assembly and generally provides a contact surface for the sealing means on the adjacent separator plate or bipolar plate. Depending on the type of electrochemical cell, the membrane itself is preferably a polymer electrolyte membrane or a polymer ion exchange membrane.

[0030] Directly beside the corrugated seal of the sealing means, there is preferably a bypass channel for the fluid flowing through the electrochemical cell. The formation of such a bypass channel can occur particularly during assembly when pressing together the components of the membrane electrode assembly and the frame means of the separator plate or bipolar plate. The shape of the bypass channel follows the route of the corrugated seal.

[0031] The electrochemical cell is preferably a polymer electrolyte fuel cell or a polymer electrolyte electrolyzer for water electrolysis or a redox flow battery. Such fuel cells are suitable for stationary applications as well as mobile applications, particularly mobile applications in motor vehicles. Description of the Drawings

[0032] The exemplary embodiments of the present invention will be described in more detail below based on the drawings. In the drawings:

[0033] Figure 1 The separator plate or bipolar plate is shown in a schematic top view,

[0034] Figure 2 The enlarged section (marked by a circle in the figure) of the separator plate or bipolar plate according to Figure 1 is shown in a perspective view,

[0035] Figure 3 The section according to Figure 2 without the sealing means is shown in a perspective view,

[0036] Figure 4 Another enlarged view of the section of Figure 1 is shown,

[0037] Figure 5 And Figure 6 show a cross-section through the bipolar plate and the membrane electrode assembly adjacent to the bipolar plate on one side in the region of the sealing means,

[0038] Figure 7a A cross-section through an injection molding tool with clamped half-sheets according to the prior art is shown,

[0039] Figure 7b Shows a cross-section of an injection molding tool with clamped half-sheets, the half-sheets having a support structure in the region of the sealing device to be formed.

[0040] Figure 8a Shows a cross-section of an injection molding tool with a clamped bipolar plate according to the prior art, the bipolar plate comprising two half-sheets.

[0041] Figure 8b Shows a cross-section of an injection molding tool with a clamped bipolar plate, the bipolar plate comprising two half-sheets, each of the two half-sheets having a support structure in the region of the sealing device to be formed.

[0042] Figure 9 Shows a perspective view of the bipolar plate in a schematic illustration, and

[0043] Figure 10 Shows a perspective view of an electrochemical cell in a battery stack. Detailed Description

[0044] Figure 1 Shows in a schematic top view the separator plate 28 or the bipolar plate 1. The separator plate 28 or the bipolar plate 1 has an active area 2 and a frame device 11 surrounding the active area 2. The frame device 11 also includes a sealing device 15, which includes a seal 16 that extends in a waveform shape in the plane (x-y plane) spanned by the separator plate 28 in a top view. A three-dimensional support structure 29 is formed in the half-sheet 3 in the region of the sealing device 15, wherein the support structure 29 is formed to protrude from the x-y plane spanned by the separator plate 28 or the bipolar plate 1 in the direction of the observer.

[0045] For flow guiding of fluids such as hydrogen, air, coolant, etc. and for discharging the fluids, three fluid outlet openings 5, 6, 7 are formed through the separator plate 28 or the bipolar plate 1 on one side of the active area 2, and another three fluid outlet openings 8, 9, 10 are formed on the opposite side of the active area 2.

[0046] Figure 2 Shows in a perspective view an enlarged section of the separator plate 28 or the bipolar plate 1 according to Figure 1 and Figure 1Reference numerals that are the same in the accompanying drawings indicate the same elements. Now, the sealing device 15 with the corrugated seal 16 on the half sheet 3 and the support structure 29 formed in the half sheet in the region of the corrugated seal 16 can be seen. In addition, the active region 2, its shaped fluid channels 21, and the bypass channel 25 adjacent to the corrugated seal 16 can be seen. In this section, the corrugated seal 16 shows four corrugated structures, each having a support structure 29 centered within the corrugated structure.

[0047] Figure 3 A section according to Figure 2 is shown in a perspective view without the sealing device 15. Figure 1 and Figure 2 Reference numerals that are the same as those in the accompanying drawings indicate the same elements. Now, the tapered shape of the three support structures 29 protruding from the half sheet 3 can be clearly seen.

[0048] Figure 4 A section in Figure 1 is shown in a further magnified view. Figures 1 to 3 Reference numerals that are the same as those in the accompanying drawings indicate the same elements. The sealing device 15 has a strip structure 17, where the corrugated seal 16 represents the innermost strip of the strip structure 17. Contrary to the other outer strips of the strip structure 17, the corrugated seal 16 depicts alternating straight sections 23 and curved sections 24 having a shape approximating a half-sine wave. The width of the corrugated seal 16 visible in a top view is designated by B D . Immediately adjacent to the corrugated seal 16, the bypass channel 25 can be seen in the direction of the active region 2. This bypass channel follows the path of the corrugated seal 16 and has a bypass channel width B B . In the case of the bypass channel 25, the straight sections are designated as 26 and the curved sections as 27. The maximum distance between the curved section 24 and the straight section 23, measured orthogonally to the straight section 23 of the corrugated seal 16, is called the maximum offset V m and represents the amplitude of the corrugated seal 16 that is deflected multiple times in the form of half-waves. The minimum radius of the corrugated seal 16, designated by M D , can be found at the transition between the straight section 23 and the curved section 24. The minimum curvature radius M D of the corrugated seal 16 is greater than the width B D of the corrugated seal, but less than the specified offset V m .

[0049] Figure 5 and Figure 6Each shows a cross-section through the bipolar plate 1 and the membrane electrode assembly 12 adjacent to the bipolar plate on one side in the region of the sealing device 15. The bipolar plate 1 has two half-sheets 3, 4 welded together. On the surface of the bipolar plate 1 facing the membrane electrode assembly 12, a sealing device 15 including a corrugated seal 16 is injection-molded on the half-sheet 3. On the surface of the bipolar plate 1 facing away from the membrane electrode assembly 12, a sealing device 15' including a corrugated seal 16' is injection-molded on the half-sheet 4. In Figure 5 it, the path of the sealing device 15 below the membrane electrode assembly 12 is indicated by a dashed line. Two coolant channels 20 are formed between the two half-sheets 3, 4 in the region of the active area 2. Two fluid channels 21 exist between the membrane electrode assembly 12 and the bipolar plate 1 in the region of the active area 2. On the side of the bipolar plate 1 facing away from the membrane electrode assembly 12, additional fluid channels 22 exist in the region of the active area 2. A central region designated 13 of the membrane electrode assembly 12 is separated from the outer region 14 of the membrane electrode assembly 12. The central region is mainly located above the active area 2, and the outer region rests on the frame device 11 and partially protrudes beyond the frame device.

[0050] In this case, when stating that one component rests on another component, this refers to the arrangement visible in the drawings and does not include any statement regarding the spatial orientation of the components during normal operation.

[0051] Figure 7a Shows a cross-section through an injection molding tool according to the prior art, which includes an upper part 18 and a lower part 19, with the half-sheet 3 clamped between the upper part and the lower part. A cavity K1 is formed between the half-sheet 3 and the upper part 18 of the injection molding tool. A cavity K2 is formed between the half-sheet 3 and the lower part 19 of the injection molding tool. Due to the clamping force of the upper part 18 on the lower part 19, the thin half-sheet 3 bulges in the direction of the cavity K1, such that the cavity K1 is smaller than the cavity K2. When the injection molding material 30 is injected into the cavities K1, K2, less injection molding material 30 is introduced into the region of the cavity K1 than into the cavity K2. After the injection molding material 30 has cured and the injection molding tool has been opened, the half-sheet 3 returns to its original flat shape. The sealing device 15 formed between the upper part 18 of the injection molding tool and the half-sheet 3 is now thinner than the required sealing device, while the sealing device 15' formed between the lower part 19 of the injection molding tool and the half-sheet 3 is thicker than the required sealing device.

[0052] Figure 7b Shows a cross-section through an injection molding tool with the clamped half-sheet 3, and the half-sheet has a support structure 29 in the region of the sealing devices 15, 15' to be formed. AndFigure 7a Like reference numerals in the drawings indicate like elements. The support structure 29 reinforces the half-sheets 3 and is supported on the upper part 18 of the injection molding tool. This prevents unwanted deformation of the half-sheets 3. When the injection molding material 30 is injected into the cavities K1, K2, the cavities K1, K2 are filled with a desired amount of injection molding material. After the injection molding material 30 has cured and the injection molding tool has been opened, the sealing devices 15 formed between the upper part 18 of the injection molding tool and the half-sheets 3 and the sealing devices 15' formed between the lower part 19 of the injection molding tool and the half-sheets 3 are present in the required dimensions.

[0053] Figure 8a A cross-section of an injection molding tool with a clamped bipolar plate 1 according to the prior art is shown. The bipolar plate includes two half-sheets 3, 4. Figure 7a Like reference numerals in the drawings indicate like elements. A cavity K1 is formed between the half-sheet 3 and the upper part 18 of the injection molding tool. A cavity K2 is formed between the half-sheet 4 and the lower part 19 of the injection molding tool. Due to the clamping force of the upper part 18 on the lower part 19, the thin half-sheets 3, 4 bulge in the direction of the cavities K1, K2, making the cavities K1, K2 smaller. When the injection molding material 30 is injected into the cavities K1, K2, less injection molding material 30 is introduced into the regions of the cavities K1, K2 than the desired injection molding material. After the injection molding material 30 has cured and the injection molding tool has been opened, the half-sheets 3, 4 return to their original flat shape. The sealing devices 15 formed between the upper part 18 of the injection molding tool and the half-sheet 3 and also the sealing devices 15' formed between the lower part 19 of the injection molding tool and the half-sheet 4 are thinner than the required sealing devices.

[0054] Figure 8b A cross-section of an injection molding tool with a clamped bipolar plate 1 is shown. The bipolar plate includes two half-sheets 3, 4, and each of the two half-sheets has a support structure 29 in the region of the sealing devices 15, 15' to be formed. Figure 7bReference numerals identical in the figures indicate identical elements. The support structure 29 reinforces the half-sheets 3, 4, and in the case of the half-sheet 3, the support structure is supported on the upper part 18 of the injection molding tool, and in the case of the half-sheet 4, the support structure is supported on the lower part 19 of the injection molding tool. This prevents unwanted deformation of the half-sheets 3, 4. When the injection molding material 30 is injected into the cavities K1, K2, the cavities K1, K2 are filled with a desired amount of injection molding material. After the injection molding material 30 has cured and the injection molding tool has been opened, the sealing devices 15 formed between the upper part 18 of the injection molding tool and the half-sheet 3 and the sealing devices 15' formed between the lower part 19 of the injection molding tool and the half-sheet 4 have the required dimensions.

[0055] Figure 9 A perspective view of the bipolar plate 1 shown in a schematic illustration. Identical Figure 1 reference numerals in the figures indicate identical elements.

[0056] Figure 10 A perspective view of the electrochemical cell 40 in the cell stack 50 including a plurality of electrochemical cells 40 is shown. The electrochemical cell 40 includes a plurality of bipolar plates 1, 1' and at least one membrane electrode assembly 12, 12' arranged between the two bipolar plates 1, 1'. The membrane electrode assembly has a central region 13 adjacent to the active region 2 and a region 14 arranged outside the active region 2 when viewed perpendicular to the plane spanned by the bipolar plate 1. A seal 16 extending in a waveform shape is located at the boundary between the regions 13, 14. See also Figure 6 .

[0057] In summary, the design of the sealing device 15 significantly contributes to the uniform flow through the active region 2 in the case of a good sealing effect and a space-saving stacking of the bipolar plates 1, 1'.

[0058] List of reference numerals

[0059] 1, 1' Bipolar plate

[0060] 2 Active region

[0061] 3 Half-sheet

[0062] 4 Half-sheet

[0063] 5 Fluid outlet opening

[0064] 6 Fluid outlet opening

[0065] 7 Fluid outlet opening

[0066] 8 Fluid outlet opening

[0067] 9 Fluid outlet opening

[0068] 10 Fluid outlet opening

[0069] 11 Frame device

[0070] 12, 12’ Membrane electrode assembly

[0071] 13 Central region of the membrane electrode assembly

[0072] 14 Outer region of the membrane electrode assembly

[0073] 15, 15’ Sealing device

[0074] 16, 16’ Wave-shaped seal

[0075] 17 Strip structure

[0076] 18 Injection molding tool, upper part

[0077] 19 Injection molding tool, lower part

[0078] 20 Coolant channel

[0079] 21 Fluid channel

[0080] 22 Fluid channel

[0081] 23 Straight section of the wave-shaped seal

[0082] 24 Bending section

[0083] 25 Bypass channel

[0084] 26 Straight section

[0085] 27 Bending section

[0086] 28 Separation plate

[0087] 29 Support structure

[0088] 30 Injection molding material

[0089] 40 Electrochemical cell

[0090] 50 Battery stack

[0091] B B Bypass channel width

[0092] B D Width of the wave-shaped seal

[0093] M D Minimum radius of the wave-shaped seal

[0094] V m Maximum offset

[0095] K1 and K2 cavities

Claims

1. A separation plate (28), comprising: A half sheet (3, 4), wherein the half sheet has an active area (2); A frame device (11) which surrounds the active area (2); and a sealing device (15, 15') which is assigned to the frame device (11) and comprises a sealing element (16, 16') which extends in a wavy shape in a top view of the plane spanned by the separation plate (28), characterized in that a three-dimensional supporting structure (29) is formed in the half sheet (3, 4) in the region of the sealing device (15, 15'), wherein the supporting structure (29) is formed to protrude from the plane spanned by the separation plate (28).

2. A bipolar plate (1), comprising: A first half sheet (3) and a second half sheet (4), each of the first half sheet and the second half sheet having an active area (2); a frame device (11), the frame device surrounding the active area (2); and a sealing device (15, 15'), the sealing device being assigned to the frame device (11) and comprising a sealing member (16, 16'), the sealing member extending in a wavy shape in a top view of the plane spanned by the bipolar plate (1), characterized in that a three-dimensional supporting structure (29) is formed in the two half sheets (3, 4) in the region of the sealing member (15, 15'), wherein the supporting structure (29) of the two half sheets (3, 4) is formed to protrude in opposite directions from the plane spanned by the bipolar plate (1) and is aligned one above the other when viewed perpendicular to the plane.

3. The separator plate (28) or the bipolar plate (1) according to claim 1 or 2, characterized in that: When viewed in a cross section through the separator plate (28) or the bipolar plate (1), the support structure (29) has a conical or hemispherical or lens-like shape.

4. The separator plate (28) or bipolar plate (1) according to one of claims 1 to 3, characterized in that The supporting structure (29) is formed in the half sheet (3, 4) in the region of the seal (16, 16') extending in a wave shape, and a supporting structure (29) is formed in the half sheet (3, 4) for each wave structure of the seal (16, 16') extending in a wave shape.

5. The separator plate (28) or the bipolar plate (1) according to one of claims 1 to 4, characterized in that The corrugated seal (16, 16') has a plurality of straight sections (23) by which a common straight line is defined, wherein the straight sections (23) are each connected to one another by a curved section (24).

6. The separator plate (28) or the bipolar plate (1) according to claim 5, characterized in that Each of the support structures (29) is arranged on a straight line which intersects the straight section (23) of the associated wave-shaped structure in a central manner and at an angle of 90°.

7. The separator plate (28) or the bipolar plate (1) according to one of claims 1 to 6, characterized in that The support structure (29) in the half-sheet (3, 4) has a height from the surface of the half-sheet (3, 4) that corresponds to the maximum thickness D±20% of the sealing device (15, 15') injection-molded onto the half-sheet (3, 4) on this surface.

8. A method for producing a sealing device (15, 15') on a separator plate (28) or a bipolar plate (1) according to one of claims 1 to 7, the method comprising the following steps: - inserting the half sheet (3, 4) or the two half sheets (3, 4) firmly connected to each other into an injection molding tool (18, 19), wherein a cavity (K1, K2) for forming a seal (15, 15') is formed between the half sheet (3, 4) and the injection molding tool (18, 19), wherein the three-dimensional support structure (29) is supported against the injection molding tool (18, 19) in the cavity (K1, K2), - injecting an injection molding material (30) into the cavity (K1, K2), wherein the support structure (29) is at least partially embedded in the injection molding material (30), - solidifying the injection molding material (30) in the cavity (K1, K2), and - demoulding the separator plate (28) or the bipolar plate (1) with the molded sealing device (15, 15') attached.

9. An electrochemical cell (40), comprising a plurality of separator plates (28) or bipolar plates (1, 1') according to one of claims 1 to 7 and at least one membrane electrode assembly (12, 12') arranged between two separator plates (28) or bipolar plates (1, 1'), the membrane electrode assembly having a central region (13) adjacent to an active area (2) and a region (14) arranged outside the active area (2) when viewed perpendicularly to a plane spanned by the separator plates (28) or the bipolar plates (1), wherein: The sealing member (16, 16') extending in a wave shape is located at the boundary between the areas (13, 14).

10. The electrochemical cell (40) according to claim 9, characterized in that The electrochemical cell is a polymer electrolyte fuel cell or a polymer electrolyte electrolyzer for electrolyzing water or a redox flow battery.

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