Bipolar plate for fuel cell

Abstract

The invention relates to a bipolar plate (100) for a fuel cell, comprising two partial plates (50, 60) which are interconnected by an adhesive connection (20). The first and second partial plates (21,..., 27) are joined in such a way that the outwardly facing surfaces of the partial plates (50, 60) respectively form the cathode side and the anode side of the bipolar plate (10), the partial plates (50, 60) each have, on at least one of their surfaces, a surface structure (51, 61) with a corresponding port (11; ..., 16) for conducting a fluid along an associated surface. An adhesive connection (20) interconnects the partial plates (50, 60) via their inner facing surfaces and has a plurality of webs (21,..., 27), said adhesive connection (20) sealing the surface structures (51, 61) relative to each other and connecting the partial plates (50, 60) to the webs (21,..., 27) at least between two adjacent ports (13; 14) through an intermediate space (40; 41) are spaced apart from each other as a multiple seal (28; 29).

Description

Technical Field

[0001] The present invention relates to a bipolar plate for a fuel cell, a method for manufacturing such a bipolar plate, and a fuel cell stack including at least one such bipolar plate. Background Technology

[0002] Various fuel cell systems are known to supply hydrogen as fuel, such as polymer electrolyte membrane (PEM) fuel cells. A fuel cell consists of electrodes (i.e., anode and cathode) with an electrolyte located between them (MEA—membrane electrode assembly). In a PEM fuel cell, the electrolyte takes the form of a membrane (i.e., a polymer electrolyte membrane (PEM)) made of an ion-conducting polymer (so-called ionomer). The PEM physically and electrically separates the two electrodes from each other, but allows a specific type of ion (in this case, protons) to pass through. Protons migrate across the membrane to the cathode, while electrons pass through an external circuit to generate electrical energy. At the cathode, protons, electrons, and oxygen react to form water.

[0003] Because the voltage of a single fuel cell is limited, multiple cells are connected in series to form a "stack" to achieve a correspondingly higher voltage. Each individual MEA is separated from the others by bipolar plates, which connect the anode and cathode of consecutive MEAs to form a series circuit. Therefore, the bipolar plates are responsible for supplying hydrogen and oxygen, venting water, and cooling the fuel cell stack. Furthermore, the bipolar plates receive electrons released from hydrogen on the anode side (hydrogen side) and ultimately redirect them to the cathode side (oxygen side).

[0004] The bipolar plate can be manufactured from two partial plates bonded together by means of a suitable adhesive, wherein coolant can be conducted in the cavity (e.g., channel structure) between the partial plates. Surface structures can be formed on the externally facing surfaces, i.e., on the anode and cathode sides respectively, to guide hydrogen or oxygen into the MEA (typically via corresponding gas diffusion layers). Various fluids can be introduced via adjacent ports / connections, while used fluids or reaction products are discharged via corresponding ports after the reaction.

[0005] Therefore, the adhesive joint not only holds the two parts of the bipolar plate together, but also acts as a seal to separate various fluids from each other during operation. Furthermore, the adhesive joint is used to seal and isolate the interior of the bipolar plate from its environment.

[0006] For a fuel cell to operate optimally, the sealing of the bonded joints must be ensured to prevent fluid mixing within the bipolar plates and to prevent fluid leakage from the bipolar plates into the environment (bonded seals). However, it is possible that the bonded seals may become defective / damaged due to adverse conditions during production, particularly leaks, or leak over time (e.g., after several years of operation), allowing fluid to pass through the seals and cause mixing or leakage. Fuel cells with such defective bipolar plates cannot operate safely, potentially necessitating the complete replacement of the associated fuel cell stack. Summary of the Invention

[0007] The object of this invention is to provide a bipolar plate with improved safety, durability, and robustness. In particular, it aims to reduce the risk of fluid mixing within the bipolar plate due to defects in the seal between the portions of the plate.

[0008] The solution to this objective is achieved based on the teachings of the independent claims. Various embodiments and modifications of the invention are the subject of the dependent claims.

[0009] A first aspect of the invention relates to a bipolar plate for a fuel cell. The bipolar plate includes a first portion plate and a second portion plate, and an adhesive connection that hermetically interconnects the first and second portion plates. The first and second portion plates are joined such that the outer-facing surfaces of the portion plates respectively form the cathode and anode sides of the bipolar plate, wherein each portion plate includes a surface structure on at least one of its surfaces, the surface structure having corresponding ports for conducting fluid along the respective surfaces. The adhesive connection interconnects the portion plates via their inner-facing surfaces and includes a plurality of connecting plates. The adhesive connection hermetically isolates the structures of the inner-facing surfaces from each other and includes at least two connecting plates spaced apart from each other by an intermediate space between at least two adjacent ports as a multiple sealing portion.

[0010] Therefore, this invention is a proposal based on a special design of the adhesive connection between partial plates of a bipolar plate. Specifically, it provides a sealing connection between two adjacent ports formed by spaced-apart plates, thereby creating a multiple seal with an intermediate space between the plates. This multiple seal significantly reduces the risk of leakage. Tightness is still ensured even if only one (or not all) plate of the multiple seal is defective, particularly leaking. The risk of fluid exchange between ports is significantly reduced compared to a single seal, which would require defects in all plates of the multiple seal. By providing an intermediate space between the plates, the probability of a defect in one plate spreading to the other is reduced. Furthermore, capillary action, which would create a direct connection between adjacent ports if both plates are defective, can be avoided or reduced. Overall, this significantly improves the safety, durability, and robustness of the bipolar plate.

[0011] While multiple seals may be important, particularly for adjacent ports used to introduce fluid, it should be understood that they can also be provided for adjacent ports to discharge used fluid or reaction products from the bipolar plates. In particular, multiple seals can be provided between adjacent ports configured to introduce oxidant (especially oxygen) or fuel (especially hydrogen), because mixing of fluids (gases) is particularly detrimental to fuel cells with correspondingly damaged bipolar plates. Especially if such a mixture comes into contact with the MEA, the damage to the fuel cell will be considerable. At the very least, the performance of the fuel cell will deteriorate drastically, and its lifespan will be significantly shortened.

[0012] The term "partial plate" as used herein specifically refers to a component of a bipolar plate that provides one of the two surfaces of the bipolar plate. Two partial plates (and, if necessary, other components such as seals, coatings, ports, etc.) together form a bipolar plate. Thus, one partial plate forms the anode side of the bipolar plate, while the other partial plate forms the cathode side. The two partial plates are also correspondingly referred to as an anode plate (or anode partial plate) and a cathode plate (or cathode partial plate). The partial plates are, in particular, substantially plate-shaped. To form the bipolar plate, they are joined together, particularly glued, wherein they can thus also be connected, particularly electrically.

[0013] The term "surface structure" as used herein specifically refers to the surface structure of a portion plate configured to conduct fluid along its surface. The channels of the surface structure can accordingly form curves (continuous or branched), allowing for uniform fluid distribution across the surface of the bipolar plate. A gas diffusion layer (GDL) is typically adjacent to the surface structures on both the anode and cathode sides. A hollow channel structure can be formed between the two portion plates, formed by the surface structure on the inward-facing surface of at least one portion plate (on one or both). This hollow channel structure can be configured to conduct coolant, which is then conducted through the bipolar plate accordingly. Thus, each of the two portion plates can each include a surface structure on two separate surfaces.

[0014] The term "port" as used herein specifically refers to a port on a bipolar plate used for introducing fluid or for discharging used fluid or reaction products. Due to the flat design, ports are typically arranged side-by-side / closely to each other and correspondingly connected to the surface structure. Ports for introduction and discharging may be located in regions at opposite edges of the bipolar plate. Therefore, the term "adjacent ports" as used herein specifically refers to (side-by-side) ports used for different fluids.

[0015] The term "multiple seal" as used herein specifically refers to a sealing design or system in which areas to be sealed and isolated from each other are sealed and isolated by more than one seal. A single seal may be formed by a single plate, and a multiple seal is correspondingly formed by multiple plates (e.g., two ("double seal") or three or more). Here, the individual plates of the multiple seal necessarily all extend between the two areas to be sealed and isolated from each other (particularly between two adjacent ports) to form, for example, a multiple seal that is all parallel to each other.

[0016] The term "joint" as used herein specifically refers to a portion of an adhesive joint, including multiple seals. A joint is specifically formed by a path along which adhesive is applied (e.g., as a so-called adhesive strip). The adhesive joint forms a sealed connection between two part plates and is therefore also referred to as an adhesive seal. A joint may also be referred to accordingly as a "sealing lip," "sealing bead," "sealing rib," etc.

[0017] The terms “comprising,” “including,” “containing,” “having,” “having,” “with,” or any other variations thereof, as may be used herein, are intended to cover non-exclusive inclusion. For example, a method or apparatus that includes or has a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to the method or apparatus.

[0018] Furthermore, unless explicitly stated otherwise, "or" refers to an inclusive "or" rather than an exclusive "or". For example, condition A or B is satisfied by one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0019] As used herein, the term “one” is defined as meaning “one or more”. The terms “another” and “other”, and any other variations thereof, should be understood to mean “at least one additional”.

[0020] The term “multiple” as used in this article should be understood to mean “two or more”.

[0021] The terms "configured to" or "set to" perform a specific function (and their corresponding modifications) should be understood in the context of this invention as meaning that the corresponding device is already designed or configured to perform the function, or at least is configured (i.e., configurable) to perform the function after a corresponding setting. This configuration can be implemented, for example, through corresponding settings of process parameters or switches for activating or deactivating functionality or settings. In particular, the device may include multiple predetermined configurations or operating modes, such that the configuration can be implemented by selecting one of these configurations or operating modes.

[0022] Preferred embodiments of the bipolar plate are described below. In each case, unless explicitly excluded or technically impossible, these embodiments can be freely combined with each other and with other aspects of the invention as further described herein.

[0023] In some embodiments, the connecting plates of the multi-seal section, together with the connecting plates extending transversely to the adhesive joint, form at least one four-sided enclosed barrier chamber as an intermediate space. Therefore, the four-sided enclosed barrier chamber not only achieves sealing isolation of each of the adjacent ports but also achieves sealing isolation of the environment. Thus, if fluid enters the sealing chamber from the relevant port due to a leak in one of the seals, it is additionally prevented from escaping from the bipolar plate into the environment surrounding the bipolar plate. This further improves safety, durability, and robustness. To achieve further improved sealing even in the case of damage to both connecting plates, particularly when the damage is staggered along the length of the connecting plates, it can be specified that the barrier chamber is divided into two or more partial barrier chambers by means of at least one additional transverse connecting plate. Furthermore, a suction system can be provided for the barrier chamber to extract the fluid that has entered the barrier chamber in the event of damage, or to extract the fluid mixture from the barrier chamber in the event of leaks in both connecting plates. Alternatively, embodiments in which the barrier chamber is filled with a barrier fluid, particularly a (viscous) liquid barrier fluid, to prevent entry into the barrier chamber are also conceivable.

[0024] In some alternative embodiments, the plates of the multi-seal section, together with the adhesive joint extending transversely to its extension, form an intermediate space, wherein the intermediate space has an opening on its periphery that opens toward the environment of the bipolar plate. Unlike the surroundingly enclosed barrier chamber described above, while the opening does not prevent fluid from escaping through one of the plates, it still improves safety, durability, and robustness, particularly compared to a single seal. In the event that all plates of the multi-seal section have damaged sections, the risk of fluid transfer between the two ports (and thus mixing in the two surface structures) can be reduced. The opening of the intermediate space to the environment allows both fluids to escape, and the lower pressure in the intermediate space compared to the ports reduces the risk of fluid (especially "foreign" fluid) entering the port area.

[0025] In some implementations, the plates of the multiple seals extend parallel to each other. This allows the multiple seals to be designed in a particularly space-saving manner. The width of the intermediate space (i.e., the distance between the plates) can be, for example, in the range of 0.75 mm to 8 mm, particularly in the range of 1.2 mm to 5 mm.

[0026] In some embodiments, the multiple seal is a double seal having two spaced-apart plates. This allows the aforementioned effects to be effectively achieved with minimal space requirements for the multiple seal. While the effects could be further enhanced, for example, by a triple seal, a double seal may still be more advantageous because this requires more space and the space not occupied by surface structures and ports on some plates is limited.

[0027] In some implementations, the individual plates, and in particular all plates, of the adhesive joint have a constant width. This improves the manufacturing of the bipolar plate. For example, the plate width can range from 2.5 mm to 3.5 mm. While an improved seal can theoretically be achieved simply by widening the plates at the desired points, patterns with different plate widths can only be achieved with increased cost. By using multiple seals with multiple plates instead of widening the plates, a manufacturing method can be achieved where the resulting adhesive joints have plates of uniform width, thereby improving the efficiency of the method. Especially in high-volume production, minimizing process time is crucial.

[0028] In some embodiments, the individual plates of the adhesive joint, and particularly all the plates, are interconnected / joined together. This also improves the manufacturing of the bipolar plate. The trajectory used to generate the plates, i.e., the application of the corresponding adhesive strip (e.g., as "adhesive strip") (see below), can be optimized such that interruptions during the application of the plates are minimized, or the plates may even be produced continuously without stopping. This improves the efficiency of the manufacturing method. Further improvements to the manufacturing method are obtained by combining the previously described constant width of the plates.

[0029] In some embodiments, the adhesive joint is formed by an adhesive material comprising a plastic material with conductive additives. For example, a two-component adhesive, such as a 2K polymer resin (e.g., 2K epoxy resin), can be used, where one component can be applied to one of the partial plates and another component to the other, such that the components react with each other when the partial plates are joined together. Components can also be provided in the form of microencapsulated adhesives. In this case, two different microencapsulated adhesives can form the two components of a two-component adhesive, and when the partial plates are joined together, the microcapsules rupture, causing the two components to mix. Alternatively, various one-component adhesives can also be used. Such adhesives, when containing conductive additives, are also called electrically conductive adhesives (ECAs). ECA formulations typically include a polymer resin component containing conductive particulate fillers (such as metal particles). The particle size is typically in the µm range. Conductivity of the adhesive joint can also be achieved by adding carbon fibers, graphite, or carbon black.

[0030] In some implementations, a portion of the plate is made of a metallic material (metal bipolar plate). The metallic material can be stainless steel, aluminum, or titanium. Stainless steel is easy to process and cost-effective. Specifically, stainless steel grades 1.4404 or 1.4435 (316L stainless steel) can be used.

[0031] In some implementations, a portion of the plate is made of a non-metallic material. This non-metallic material can be a plastic material with conductive components, such as an epoxy-carbon mixture. For example, it can be a mixture of an epoxy or phenolic resin-based (thermosetting) curing binder (e.g., <25%) with a proportion of industrial carbon black (conductive carbon black particles) (e.g., <5%), graphite (e.g., <85%), a release agent (<5%), and a stabilizer (e.g., <3%). Such a bipolar plate can be referred to as a carbon bipolar plate or a carbon / composite bipolar plate.

[0032] In some implementations, a portion of the plate is manufactured using the metal material described above as the core and the non-metal material described above as the coating (hybrid bipolar plate).

[0033] A second aspect of the invention relates to a method for manufacturing a bipolar plate, particularly a bipolar plate according to the first aspect. Here, a first portion plate and a second portion plate are provided, each having a surface structure on at least one of its surfaces, the surface structure having corresponding ports for conducting fluid along the respective surfaces. An adhesive is then applied in strips (i.e., linearly) to the surface of at least one of the portion plates, wherein two strips spaced apart from each other are applied between at least two adjacent ports. The portion plates are then joined together, for example, by pressing them together, such that the outward-facing surfaces of the portion plates respectively form the cathode side or anode side of the bipolar plate. An adhesive joint with a plurality of connecting plates is formed between the portion plates by the adhesive strips, the adhesive joint sealing and isolating the surface structures from each other, and having at least two connecting plates spaced apart from each other by an intermediate space between at least two adjacent ports as a multiple sealing portion.

[0034] In some implementations, adhesive is applied to at least one of the portions of the plate by means of screen printing or by means of a dispenser, such that the strips have a uniform width. As explained above regarding the splice, a constant strip width can improve the efficiency of the method, which is particularly advantageous for high-volume production. This applies to both screen printing methods (if laser steel is used for screen fabrication) and dispenser methods, as it makes it possible to apply all strips with the same nozzle, constant nozzle pressure, constant nozzle speed, etc. A constant width of the splice also facilitates bonding, because in this way, the amount of adhesive along all splices (i.e., over the entire adhesive joint) and therefore the bond strength is constant. Furthermore, the design of the plate can be simplified, as the same features of the adhesive joint can be considered throughout the (partial) plate.

[0035] In screen printing, adhesive is applied to a section plate through a fine-mesh screen. The screen has impermeable areas and areas that allow the adhesive to pass through. The section plate is positioned, the screen is placed over it, and the adhesive is applied over the screen. Using a squeegee, the adhesive is pressed through the screen onto the section plate, thereby forming the desired strip. In a dispenser method, adhesive is applied from a nozzle (dispenser) to the section plate in a controlled manner. This can be accomplished using an automated system that can meterly supply the adhesive and precisely apply it into the desired strip. The dosage and speed can be adjusted as needed to ensure accurate and uniform distribution.

[0036] A third aspect of the invention relates to a fuel cell stack comprising at least one fuel cell having at least one bipolar plate according to the first aspect or at least one bipolar plate produced using the method according to the second aspect.

[0037] The features and advantages explained with respect to the first aspect of the invention also apply to the other aspects of the invention. Attached Figure Description

[0038] Further advantages, features and possible applications of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0039] In the attached diagram:

[0040] Figure 1 An exploded view of a bipolar plate according to a first embodiment is shown;

[0041] Figure 2 Showing from Figure 1 A top view of one of the plates in a bipolar plate;

[0042] Figure 3 Showing from Figure 2 Detailed images;

[0043] Figure 4a , Figure 4b , Figure 4c Showing from Figure 3 Detailed images show various defects in the multiple sealing sections;

[0044] Figure 5 Detailed diagrams according to the second embodiment are shown; and

[0045] Figure 6a , Figure 6b , Figure 6c Showing from Figure 5 The detailed diagram shows various defects in the multiple sealing sections.

[0046] Throughout the figures, the same reference numerals are used for the same or corresponding elements of the invention. The figures are schematic and therefore do not necessarily show the actual situation to scale. Detailed Implementation

[0047] Figure 1 A bipolar plate 10 according to a first embodiment is shown in an exploded view. The bipolar plate 10 has a first portion plate 50 forming, for example, the cathode side and a second portion plate 60 correspondingly forming the anode side. In operation within the fuel cell stack, each MEA is adjacent to the cathode side and the anode side, respectively. Corresponding ports 11, 12, 13, 14, 15, and 16 are provided. Cathode gas (oxidant, particularly oxygen) is input via inlet 12 of the bipolar plate 10 and then flows along a surface structure 51 across the cathode side of the bipolar plate 10, which is formed, for example, by a plurality of corresponding channels. Corresponding reaction products (particularly water) exit the bipolar plate 10 via outlet 15. Anode gas (fuel, particularly hydrogen) is similarly input via inlet 11 and flows along the corresponding surface structure 61 (in… Figure 1 The invisible surface structure 52 (which corresponds to surface structure 51) flows through the anode side. Residue is discharged via outlet 14. Coolant is input via inlet 13, flows through a hollow channel inside the bipolar plate 10, and finally exits the bipolar plate 10 at outlet 16. The hollow channel inside the bipolar plate 10 is formed by surface structures 52 and 62 on the inward-facing surfaces of portions of plates 50 and 60. The invisible surface structure 52 corresponds in design to surface structure 62.

[0048] Parts 50 and 60 of the bipolar plate 10 are interconnected by an adhesive connection 20, which simultaneously seals and isolates different fluid regions from each other and from the environment 70 of the bipolar plate 10. Figure 2 The top view shows a portion of plate 60 with adhesive connection 20. In addition to the connecting plates of the multi-seal portion 28, which is described in more detail below, the adhesive connection also includes connecting plates 21, 22, 23, and 24, all of which are interconnected. Connecting plates 21 and 22 on the periphery are used for sealing isolation from the environment 70, while connecting plates 23 and 24 isolate the ports from the internal seal. In the areas of outlets 14 and 15, a single seal may be sufficient instead of the multi-seal portion 28', as any mixing of fluids at the outlet is less critical.

[0049] As a material for bonding joints, conductive adhesives (ECAs) can be used in particular to form electrical connections between two part plates 50, 60. ECA formulations typically consist of a polymer resin component with conductive particulate fillers.

[0050] exist Figure 3A detailed view of the adhesive joint 20 of the bipolar plate 10 according to a first embodiment is shown. Specifically, the adhesive joint 20 in the region of adjacent ports 11, 12 is shown here. The seal between these two ports is particularly important to prevent the mixing of anolyte and cathode gases at the inlet. Therefore, a multiple seal 28 is provided, specifically formed by connecting plates 25, 26 located between ports 11, 12 and spaced apart from each other by an intermediate space 40. According to this embodiment, the intermediate space 40 is closed by lateral connecting plates 22, 24, thereby forming a barrier chamber enclosed on all four sides.

[0051] Figure 4a , Figure 4b and Figure 4c Different scenarios are illustrated in which the multiple seals 28 have different defects 31, 32 in the connecting plates 25, 26, which may cut through the respective connecting plates and thus cause fluid to pass through the respective connecting plates (“leakage”).

[0052] exist Figure 4a and Figure 4b In this configuration, only one of the connecting plates 25 and 26 has a corresponding defect 31 or 32. Since the other connecting plate 25 and 26 remains intact, the fluid only escapes into the intermediate space 40, thus ensuring the seal between ports 11 and 12. Furthermore, the enclosed shape on all sides prevents fluid from escaping into the environment 70 of the bipolar plate 10.

[0053] exist Figure 4c In the process, both connecting plates 25 and 26 have defects 31 and 32, respectively. While this may still lead to mixing of the two fluids, the probability is significantly reduced. If the probability of only one of the connecting plates 25 and 26 having a defect is, for example, 1%, then... Figure 4c The probability of the scenario shown is only 0.01%.

[0054] exist Figure 5 The image shows a detailed view of the adhesive connection 20 of the bipolar plate 10 with multiple sealing portions 29 according to the second embodiment. Compared with the multiple sealing portions 28 of the first embodiment, the connecting plate 22 forming a seal with the environment 70 of the bipolar plate 10 has an opening (notch) 42 in the region of the intermediate space 41. Therefore, the intermediate space 41 is not closed on all sides as in the first embodiment, but is open to the environment 70.

[0055] exist Figure 6a , Figure 6b and Figure 6c In, with Figure 4a , Figure 4b and Figure 4cSimilarly, different scenarios are shown where the multiple sealing sections 29 have different defects 31, 32 in the connecting plates 25, 26, which may cut through the respective connecting plates and thus cause fluid to pass through the respective connecting plates.

[0056] exist Figure 6a and Figure 6b In this configuration, only one of the plates 25 and 26 has a defect 31 or 32. Since the other plate 25 or 26 remains intact, the fluid only escapes into the intermediate space 41, thus ensuring the seal between ports 11 and 12. However, fluid can reach the environment 70 from the intermediate space 41 (dashed arrow). However, this is less critical than the mixing of fluids within the bipolar plates, and therefore this risk is acceptable.

[0057] exist Figure 6c In this configuration, the two connecting plates 25 and 26 each have defects 31 and 32. Due to the open design of the intermediate space 41, fluid can escape into the environment 70. This reduces the risk of mixing of fluids from the two ports 11 and 12, because the outward-opening design of the intermediate space 41 results in a lower pressure there than in the regions of ports 11 and 12. Therefore, the two fluids escaping through defects 31 and 32 are more likely to escape into the environment 70 through opening 42 (indicated by the dashed arrow) rather than seep into the regions of adjacent ports 11 and 12 through another defect 31 and 32.

[0058] While at least one exemplary embodiment has been described above, it should be noted that numerous variations exist. It should also be noted that the described exemplary embodiments represent only non-limiting examples and are not intended to limit the scope, applicability, or configuration of the devices and methods described herein. Rather, the foregoing description will provide guidance to those skilled in the art for implementing at least one exemplary embodiment, where it should be understood that various changes can be made to the operation and arrangement of the elements described in the exemplary embodiments without departing from the subject matter defined in the appended claims and their legal equivalents.

[0059] List of reference numerals in the attached diagram:

[0060] 10 Bipolar Plates

[0061] Port 11 (Entry Point)

[0062] 12 Ports (Entry Points)

[0063] Port 13 (Entry Point)

[0064] 14 Ports (Exit Points)

[0065] 15 Ports (Exit Points)

[0066] 16 ports (egress)

[0067] 17 Surface Structure

[0068] 20 Sealing part (adhesive joint)

[0069] Connecting plates 21 to 27

[0070] 28, 29 Multiple sealing parts

[0071] 31, 32 Defects (Leakage)

[0072] 40. Intermediate Space (Barrier Room)

[0073] 41 Intermediate Space

[0074] 42 Opening

[0075] 50-part board

[0076] 51 Externally facing surface structure

[0077] 52. Inward-facing surface structure

[0078] 60-part board

[0079] 61 Externally facing surface structure

[0080] 62. Inward-facing surface structure

[0081] 70. Environment.

Claims

1. A bipolar plate (10) for a fuel cell, comprising: - A first portion plate (50) and a second portion plate (60), the first portion plate and the second portion plate being joined together such that the externally facing surfaces of the portion plates (50, 60) respectively form the cathode side and the anode side of the bipolar plate (10), the portion plates (50, 60) each including a surface structure (51, 61) on at least one of their surfaces, the surface structure having corresponding ports (11; ..., 16) for conducting fluid along the respective surface; as well as - An adhesive connection (20) that interconnects the partial plates (50, 60) via their inward-facing surfaces and includes a plurality of connecting plates (21, ..., 27), the adhesive connection (20) sealingly isolating the surface structures (51, 61) from each other, and includes an intermediate space (40) between at least two adjacent ports (11; 12). 41) At least two spaced-apart plates (25, 26) serve as a multiple sealing section (28; 29).

2. The bipolar plate according to claim 1, wherein, The connecting plates (25, 26) of the multiple sealing section (28) together with the connecting plates (22, 24) of the adhesive connection section (20) extending transversely to the connecting plates of the multiple sealing section form at least one enclosed barrier chamber as an intermediate space (40).

3. The bipolar plate according to claim 1, wherein, The connecting plates (25, 26) of the multiple sealing portion (29) together with the connecting plate (24) of the adhesive connection portion (20) extending transversely to the connecting plates of the multiple sealing portion form the intermediate space (41), which has an opening (42) on its periphery that opens toward the environment (70) of the bipolar plate (10).

4. The bipolar plate according to any one of the preceding claims, wherein, The connecting plates (25; 26) of the multiple sealing parts (28; 29) extend in parallel.

5. The bipolar plate according to any one of the preceding claims, wherein, The multiple sealing parts (28; 29) are double sealing parts having two plates spaced apart from each other.

6. The bipolar plate according to any one of the preceding claims, wherein, The connecting plates (21, ..., 27) of the adhesive connection (20) have the same width.

7. The bipolar plate according to any one of the preceding claims, wherein, The various connecting plates (21, ..., 27) of the adhesive connection are connected as one unit.

8. A method for manufacturing a bipolar plate (10) for a fuel cell, wherein, The method includes: - Provide a first portion plate (50) and a second portion plate (60), each of the first portion plate and the second portion plate having a surface structure (51, 61) on at least one of their surfaces, the surface structure having corresponding ports (11; ..., 16) for conducting fluid along the respective surface; - Apply adhesive in strips to the surface of at least one of the partial plates (50, 60), wherein two strips spaced apart from each other are applied between at least two adjacent ports (13, 14); - The partial plates (50, 60) are joined such that the externally facing surfaces of the partial plates (50, 60) respectively form the cathode side and anode side of the bipolar plate (10), wherein an adhesive connection (20) with multiple connecting plates (21, ..., 27) is formed between the partial plates (50, 60) by adhesive strips, the adhesive connection sealingly isolating the surface structures (51, 61) from each other, and includes at least two connecting plates (25, 26) spaced apart from each other by intermediate spaces (40; 41) between at least two adjacent ports (13, 14) as a multiple sealing part (28; 29).

9. The method according to claim 8, wherein, The adhesive is applied to at least one of the portion plates (50, 60) by means of screen printing or by means of a dispenser, such that the strips have the same width.

10. A fuel cell stack comprising at least one bipolar plate (10) according to any one of claims 1 to 7 or a bipolar plate (10) produced according to the method according to claim 8 or 9.

Images