Fuel cell stack
By alternately stacking bipolar plates and membrane electrode assemblies in the fuel cell stack, and using end plates with protruding connecting elements as bottom plates and top plates of the housing, the problems of large weight and complex assembly of the traditional fuel cell stacks are solved, and lightweight and cost-effective manufacturing is achieved.
Patent Information
- Application Number
- CN202380057038.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-08-03
- Filing Date
- 2023-07-05
- Publication Date
- 2025-03-14
AI Technical Summary
Traditional fuel cell stacks have high manufacturing costs and high weight due to the large number of components and require precision assembly.
A lighter fuel cell stack is designed to reduce the number of parts and simplify the assembly process by alternately stacking bipolar plates and membrane electrode assemblies in the stack and utilizing end plates with protruding connecting elements as the base plate and top plate of the housing.
The lightweight and cost-effective manufacturing of the fuel cell stack is achieved, reducing assembly complexity and weight, while ensuring the sealing and stable operation of the fuel cell stack.
Smart Images
Figure CN119631209A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a fuel cell stack. Background Art
[0002] Generally, a fuel cell stack includes: a stack body including a plurality of membrane electrode assemblies (MEAs) separated by so-called bipolar plates (BPPs); a pair of terminal plates for collecting current generated by the stack body; and a pair of end plates for clamping the terminal plates. Generally, an insulating plate is provided between each terminal plate and an adjacent end plate to insulate each terminal plate from the adjacent end plate.
[0003] The bipolar plate itself usually includes at least two conductive metal plates, so-called flow field plates, which are stacked on each other, and the flow field plate has a flow field for reactants on one side and a flow field for cooling fluid on the other side. Therefore, the flow fields of the cooling fluid face each other, wherein the flow field of the reactant fluid faces the MEA. Each bipolar plate and / or membrane electrode assembly includes fuel, oxidant and coolant inlet manifolds, and fuel, oxidant and coolant outlet manifolds. In the assembled stack, each manifold forms a tubular channel that extends through the entire fuel cell stack body and transports the corresponding fluid into the fuel cell stack and outputs it from the fuel cell stack. The flow field of each plate forms an active area for generating electrical energy, wherein the active area is arranged between the inlet manifold and the outlet manifold of each unit fuel cell.
[0004] In addition, in order to provide touch protection and / or protection from environmental influences such as water and / or dust, the fuel cell stack is encapsulated in a housing, which includes a bottom plate, a top plate and side walls, wherein sealing elements can be arranged between different elements of the housing to achieve a sealed environment for the fuel cell stack within the housing, thereby ensuring safe and stable operation of the fuel cell stack.
[0005] However, conventional fuel cell stacks can become quite heavy due to the number of different components, and can be expensive and labor-intensive to manufacture because the components must be manufactured to close tolerances on a case-by-case basis to ensure proper function of the fuel cell stack, and the components also need to be assembled. Summary of the invention
[0006] It is therefore an object of the present invention to provide a fuel cell stack which is lighter and can be produced simply and cost-effectively.
[0007] This object is achieved by a fuel cell stack according to claim 1 .
[0008] Hereinafter, a fuel cell stack is provided, which includes a fuel cell stack body having a plurality of unit fuel cells. Each unit fuel cell includes a bipolar plate and a membrane electrode assembly, which are alternately stacked in a stacking direction. Therefore, each bipolar plate and / or membrane electrode assembly may include at least a fuel, oxidant and coolant inlet manifold, and at least a fuel, oxidant and coolant outlet manifold. Preferably, the manifold may form a corresponding tubular channel extending through the fuel cell stack body for delivering the corresponding fluid into and out of the fuel cell stack, wherein each unit fuel cell has an active area for generating electrical energy, wherein the active area is arranged between the inlet manifold and the outlet manifold of each unit fuel cell.
[0009] The fuel cell stack also includes a first terminal plate and a second terminal plate for clamping the fuel cell stack body, wherein the first terminal plate and the second terminal plate are suitable for collecting the electrical energy generated by the fuel cell stack body. In addition, the fuel cell stack includes a first end plate and a second end plate for clamping the fuel cell stack body. Therefore, at least one end plate may include at least one inlet opening and at least one outlet opening, wherein at least one inlet opening is aligned with one or more inlet channels, and at least one outlet opening is aligned with one or more outlet channels. For example, at least one end plate may include at least fuel, oxidant and coolant inlet openings, and at least fuel, oxidant and coolant outlet openings. In addition, an insulating plate may be provided between one of the terminal plates and an adjacent end plate.
[0010] Furthermore, the fuel cell stack comprises an outer shell having at least a bottom plate, a stack cover configured to cover the sides of the fuel cell stack, and a top plate. In particular, the top plate may be connected to the stack cover or may be formed integrally with the stack cover. The stack cover may be formed as a hollow box or may be formed by a plurality of separate side walls connected to each other to form a hollow box.
[0011] In order to reduce the number of components of the fuel cell stack and reduce the complexity of the fuel cell stack assembly process, the first end plate is configured as a bottom plate of the housing and is provided with at least one protruding connecting element, which protrudes laterally from the first end plate and is configured to connect the stack cover to the first end plate. This allows the bottom plate of the housing to be omitted, so that the entire fuel cell stack has a lighter weight and fewer components, which makes the assembly process simpler and the finished fuel cell stack lighter and saves costs. Advantageously, the second end plate can be further configured as a top plate of the housing. This reduces the number of components, thereby further reducing the weight of the fuel cell stack.
[0012] Furthermore, the first end plate may be provided with a plurality of protruding connection elements. The plurality of protruding connection elements may be discretely arranged at the periphery of the first end plate. This has the advantage that the stack casing may be securely fixed to the first end plate.
[0013] Alternatively, at least one protruding connection element can be configured as a flange extending along the entire periphery of the first end plate. This has the advantage that the stack housing can be evenly fixed around the first end plate. In addition, this allows to simplify the sealing of the housing to prevent external contaminants, as will be further explained below.
[0014] Furthermore, at least one protruding connecting element may comprise at least one fastening interface for fastening the stack cover to the at least one protruding connecting element and thereby to the first end plate. This allows the stack cover to be further fastened to the first end plate. Preferably, the fastening interface may be configured to removably fasten the stack cover to the protruding element. The advantage of this is that the housing can be easily removed for easy access to the fuel cell stack (e.g. for maintenance) and then reinstalled. The fastening interface may be configured to press fit and / or form fit the stack cover to the protruding connecting element. For example, the fastening interface may be a hole in a groove, a clamping element, a latch, a snap, a lug and / or a protruding connecting element, such as a threaded through hole or a threaded blind hole, or a through hole through which the fastening element can pass.
[0015] According to another embodiment, at least one sealing element is provided, which is configured to provide a seal between at least one protruding connection element and the stack cover. This allows a sealed environment of the fuel cell stack to be achieved within the housing, thereby ensuring safe and stable operation of the fuel cell stack. More specifically, the stack cover can be against the top of at least one protruding connection element or on the side of at least one protruding connection element. In the case where the stack cover is against the top of at least one protruding connection element, at least one sealing element can be arranged between the stack cover and the protruding connection element, so that at least one sealing element is compressed by gravity, thereby improving the sealing between the stack cover and the end plate or more specifically with the protruding connection member. However, at least one sealing element can also be compressed in other ways. For example, the fastening element that fixes the stack cover to the protruding connection element can be further configured to compress at least one sealing element. Therefore, even in the case where the stack cover is against the side of the protruding connection element, the sealing between the stack cover and the protruding connection element can be improved by compressing at least one sealing element by means of the fastening element.
[0016] Furthermore, at least one sealing element is arranged at the at least one protruding connection element and / or at the stack casing. Preferably, the at least one sealing element is fixed to the protruding connection element or the stack casing. For example, the at least one sealing element can be permanently or removably fixed to the protruding connection element or the stack casing. This has the advantage that the at least one sealing element is fixed in place.
[0017] Furthermore, at least one sealing element can be a continuous sealing element. In particular, in combination with the flange, this allows an improved gas-tight sealing of the fuel cell stack within the housing. If a gas-tight sealing of the housing is not required, for example, if only touch protection is required, a plurality of discrete sealing elements can also be provided. These elements can preferably interact with discrete protruding connecting elements.
[0018] Preferably, at least one sealing element is arranged in a groove. Furthermore, at least one sealing element can be fixed to a protruding connection element (in particular a flange or a stack casing) by friction, press fit, attachment with an adhesive and / or molding. For example, at least one sealing element can include a U-shaped structure that can be arranged at the edge of the stack casing. Furthermore, at least one sealing element can be molded, clamped and / or bonded.
[0019] Furthermore, at least one of the protruding connection elements may comprise a groove. The groove may be configured to receive a portion of the stack cover, such as an edge of the stack cover and / or at least one sealing element. This has the advantage that the position of the stack cover and / or the position of at least one sealing element on the first end plate may be aligned and / or fixed. Preferably, the groove is deep enough to include at least one sealing element. This may improve the gas-tight sealing of the fuel cell stack within the housing. Alternatively, the groove may only receive at least one sealing element.
[0020] According to another embodiment, the end plate includes a base and a step, wherein at least one protruding connecting element is arranged at the base, and wherein the step includes input and output ports and / or terminals for the operation of the fuel cell stack. For example, the input and output ports and terminals may include inlet openings for reactants and / or coolants, outlet openings for reactants and / or coolants, at least one output terminal for the generated electrical energy, and / or at least one terminal for monitoring the fuel cell stack. Preferably, the step is recessed by a predetermined amount relative to the base. This allows sufficient space to be provided between the components arranged at the step in the stack cover and the fuel cell stack (e.g., a compression element that may be used to compress the fuel cell stack).
[0021] Preferably, at least the first end plate comprises at least one reinforcing element (in particular for strengthening the ability of the first end plate to resist deformation forces). In particular, the at least one reinforcing element may be embedded in the first end plate. For example, the at least one reinforcing element may be overmolded with the material of the first end plate or inserted into the material of the first end plate. Preferably, the at least one reinforcing element is made of metal (such as a metal rod or a metal tube). This may increase the resistance of the first end plate to deformation forces. For example, the at least one reinforcing element may be a hollow element or a solid element. Furthermore, the at least one reinforcing element may be a profiled element and / or may include an opening, into which the material forming the end plate may enter.
[0022] Additionally or alternatively, at least one reinforcing element may be a frame having at least one rod having a circular, triangular, rectangular, elliptical or polygonal cross section. Preferably, at least one reinforcing element is arranged in a stepped portion of the first end plate. Furthermore, the reinforcing element may be adapted to serve as an anchor point for anchoring a compression element configured to compress the fuel cell stack in the stacking direction. This has the advantage that the compression element can be directly attached to the stable structure of the end plate.
[0023] According to another embodiment, at least the first end plate is made of an electrically insulating material. By making the first end plate of an electrically insulating material, the first end plate can advantageously be at least partially arranged in direct contact with the terminal plate, and an additional insulating plate can be omitted. Thus, the number of components can be further reduced, and the assembly process can be simplified, as fewer components need to be assembled. Since the end plate itself can be made at least partially of an electrically insulating material, there is no risk of a short circuit even if the terminal plate is in direct contact with the end plate.
[0024] Additionally or alternatively, at least one of the end plates may be at least partially coated with an electrically insulating material in the area in direct contact with the adjacent terminal plate. For example, the end plate may be at least partially made of a metal coated with an electrically insulating material. This has the advantage that the metal may provide the necessary strength and / or stability required of the end plate, while the electrically insulating material forms a coating for providing electrical insulation.
[0025] Furthermore, the plastic material may be a fiber reinforced plastic material. The advantage of a fiber reinforced plastic material is that it can provide higher strength and / or stability than a plastic material while also having electrical insulation properties. For example, the fiber reinforced plastic material may be a glass fiber reinforced molding compound, a glass fiber reinforced epoxy resin, a glass fiber reinforced polyester and / or a glass fiber reinforced phenolic molding compound.
[0026] Preferably, the electrically insulating material is a moldable material, wherein preferably at least one end plate is molded. Advantageously, the end plate can be formed by a molding process (e.g. injection molding). This allows a cost-effective manufacturing process. For example, the electrically insulating material can be a composite plastic, a thermosetting composite material and / or a phenolic plastic. Thermosetting plastic materials have the advantage that they do not change shape even when heated.
[0027] Preferably, at least one of the end plates comprises a groove, wherein the groove is formed in a surface of the end plate facing the adjacent terminal plate, and wherein the groove is sized to receive the terminal plate. This allows the overall height of the fuel cell stack to be reduced. Furthermore, the depth of the groove may also be designed so that the entire height of the terminal plate can be received in the groove. Alternatively, the depth of the groove may also be designed so that only a portion of the height of the terminal plate is located within the groove.
[0028] In addition, the size and / or depth of the groove can be designed so that the groove is also suitable for incorporating a heating element, which is configured to heat the fuel cell stack body. The heating element can be configured to provide thermal energy to the fuel cell stack or a component of the fuel cell stack to compensate for heat losses occurring during operation of the fuel cell stack or to heat the fuel cell stack during startup. By placing the heating element also in the groove of the end plate, the height of the fuel cell stack is further reduced.
[0029] According to another embodiment, at least the first end plate is at least partially in direct contact with the terminal plate, and at least one end plate comprises at least one surface structural element suitable for avoiding any current creepage between the terminal plate and the conductive part of the end plate. Although the end plate is electrically insulated, current creepage is still possible. Current creepage or leakage current is an uncontrollable undesirable current that flows along the surface of the insulating material between two conductors. The shortest path for these currents to flow on the surface of the insulating material is called creepage distance. Over time, these fault currents on the surface of the insulating material may cause changes in the insulating material.
[0030] For example, at least one surface structure element may be arranged near the conductive element. Preferably, at least one surface structure comprises at least one rib and / or groove and / or a plurality of ribs and / or grooves. Additionally or alternatively, at least one structure element is arranged at the periphery of at least one end plate and / or at a recess formed in at least one end plate. The conductive element may be a terminal plate, a reinforcement element and / or any other metal component. Furthermore, a plurality of surface structure elements may be provided on at least one end plate.
[0031] Further preferred embodiments are defined in the dependent claims as well as in the description and drawings. Hence, elements described or shown in combination with other elements may exist alone or in combination with other elements without departing from the scope of protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In the following, preferred embodiments of the present invention are described in conjunction with the accompanying drawings, wherein the accompanying drawings are only exemplary and are not intended to limit the scope of protection. The scope of protection is limited only by the attached claims.
[0033] The accompanying drawings show:
[0034] Figure 1 : A schematic perspective exploded view of a fuel cell stack according to an embodiment,
[0035] Figure 2 : Figure 1 A schematic perspective view of an end plate of a fuel cell stack in FIG.
[0036] Figure 3 : Side view of the fuel cell stack. DETAILED DESCRIPTION
[0037] In the following, elements with the same or similar functions are denoted by the same reference numerals.
[0038] Figures 1 to 3 A fuel cell stack 100 according to an embodiment is shown. The fuel cell stack includes a fuel cell stack body 102 having a plurality of unit fuel cells. Each unit fuel cell includes a bipolar plate and a membrane electrode assembly, which are alternately stacked in a stacking direction 104, wherein each bipolar plate and / or membrane electrode assembly may include at least a fuel, oxidant and coolant inlet manifold, and at least a fuel, oxidant and coolant outlet manifold. The manifold may form a corresponding tubular channel 106 extending through the fuel cell stack body 102 for providing a corresponding flow to and from the fuel cell stack 100. Each unit fuel cell has an active area 108 for generating electrical energy, wherein the active area 108 is arranged between the inlet manifold and the outlet manifold of each unit fuel cell.
[0039] The fuel cell stack 100 further includes first and second terminal plates 110 that clamp the fuel cell stack body 102. The first and second terminal plates 110 are used to collect the electrical energy generated by the fuel cell stack body 102 in the active area 108. In addition, the fuel cell stack further includes a first end plate 1 and a second end plate 3 that clamp the fuel cell stack body 102.
[0040] In addition, the fuel cell stack 100 is provided with a housing 18 ( Figure 3 ), the housing 18 can be used for touch and / or environmental protection. The housing 18 includes a stack cover 20 configured to cover the sides of the fuel cell stack 100 and a top plate 22. The bottom plate of the housing 18 is formed by the first end plate 1, such as from Figure 3 As shown in . The top plate 22 is connected to the stack cover 20 via a fastening interface 24, and the stack cover 20 is formed by a plurality of separate side walls 20-1, 20-2 connected to each other to form a hollow box. Alternatively, the stack cover 20 can be formed as a hollow box, and / or the top plate 22 can be formed integrally with the stack cover 20, or the second end plate 3 can be configured as the top plate 20.
[0041] In order to simultaneously serve as a base plate for the housing 18, the end plate 1 is provided with a protruding connection element 14, which protrudes laterally from the first end plate 1 and is configured to connect the housing 18 to the first end plate 1. In the described embodiment, the protruding connection element is a flange 14, which surrounds the periphery of the end plate 1. Alternatively, in particular if only touch protection is required, the first end plate 1 may be provided with a plurality of individual protruding connection elements, wherein the plurality of protruding connection elements are arranged around the periphery of the first end plate 1.
[0042] In the depicted embodiment, the housing 18 rests on the top of the flange 14, as shown in FIG. Figure 3 As shown. In order to attach the shell 18 to the end plate 1, the flange 14 has a plurality of fastening interfaces 16 for fixing the shell 18 on the end plate 1. In the illustrated embodiment, the fastening interfaces 16 are threaded blind holes arranged in the flange 14 along the stacking direction 104. However, the fastening interfaces 16 may also be threaded through holes or through holes into which fastening elements can be inserted. Alternatively, the stack cover 20 may be located on the side of the flange 14. In this case, the threaded blind holes used as fastening interfaces may be arranged in the side of the flange 14 perpendicular to the stacking direction 104.
[0043] In order to ensure the gas-tight sealing of the fuel cell stack, a continuous sealing element 26 is provided between the flange 14 and the housing 18 or the stack cover 20 for sealing. In the embodiment shown, the sealing element 26 is arranged in a groove 28 provided in the flange 14. Alternatively, the sealing element 26 can be fixed to the protruding connecting element 14 or the stack cover 20. For example, the sealing element 26 can be fixed by friction, press fit, attachment with an adhesive, molding, clamping and / or gluing. Figure 3 It can be seen that the stack casing 20 rests on the top of the flange 14 so that the sealing element 26 is compressed by the weight of the stack casing 20 due to gravity even before the stack casing 20 is fastened to the first end plate 1 .
[0044] It can be seen that the end plate 1 is T-shaped, the base of which is formed by a flange 14 and has a stepped portion, wherein the stepped portion includes input and output ports and / or terminals for operation of the fuel cell stack 100, such as input and output openings 2a, 2b, 2c, 4a, 4b, 4c. More specifically, the first end plate 1 has fuel, oxidant and coolant inlet openings 2a, 2b, 2c and fuel, oxidant and coolant outlet openings 4a, 4b, 4c.
[0045] like Figure 1 As shown, the inlet openings 2a, 2b, 2c and the outlet openings 4a, 4b, 4c are aligned with the inlet and outlet channels 106 extending through the fuel cell stack body 102 for providing the corresponding flows to and from the fuel cell stack 100. In this case, the second end plate 3 is adapted to terminate the inlet and outlet channels 106. Alternatively, the inlet openings 2a, 2b, 2c and the outlet openings 4a, 4b, 4c may be distributed between the first end plate 1 and the second end plate 3.
[0046] from Figure 1As can be seen in the figure, the first end plate 1 and the second end plate 3 are at least partially in direct contact with the terminal plate 110. In order to avoid any short circuit between the terminal plate 110 and the first end plate 1 and the second end plate 3, the end plates 1 and 3 are made of plastic material to electrically insulate the end plates 1 and 3. Alternatively, an insulating plate made of an electrically insulating material can be provided between the end plates 1 and 3 and the terminal plate 110.
[0047] The plastic material forming the first end plate 1 may be a formable plastic material, so that the end plate 1 may be formed by a molding process such as injection molding.
[0048] Furthermore, in the embodiment shown, the end plate 1 comprises three reinforcing elements 6 embedded in the plastic material. However, any other number of reinforcing elements 6 may be selected depending on the size of the end plate 1 and / or the expected loads to which the end plate 1 will be subjected. Figure 3 As shown, the reinforcement element 6 is a cylindrical rod extending through the end plate 1. For example, the reinforcement element 6 may be overmoulded with an electrically insulating material. Alternatively, the reinforcement element 6 may be inserted into the end plate 1.
[0049] Alternatively, the reinforcing element 6 may form a frame with metal rods having a circular, triangular, rectangular, oval or polygonal cross section. Depending on the size of the end plate 1 and / or the expected loads on the end plate 1, the reinforcing element may be a hollow element or a solid element. Furthermore, the reinforcing element 6 may be a profiled piece and / or may include openings into which the material forming the end plate 1 may enter. Of course, different types of reinforcing elements 6 may be used in one end plate 1.
[0050] The end plate 1 shown in the present embodiment is made of a plastic material, so that an additional insulating plate between the end plate 1 and the adjacent terminal plate 110 can be omitted. As can be further seen in the illustrated embodiment, the end plate 1 includes a groove 8 formed in a surface 10 of the end plate 1 facing the adjacent terminal plate 110. The size of the groove 8 is designed to receive the terminal plate 110. For example, the depth of the groove 8 can be designed so that the entire height of the terminal plate 110 can be received in the groove 8. Alternatively, the depth of the groove 8 is such that the height of the terminal plate 110 is only partially located in the groove 8.
[0051] Furthermore, the end plate 1 is provided with a surface structural element 12, which is suitable for avoiding any current creepage between a conductive element, such as the terminal plate 110, and a conductive part of the end plate 1. For example, the surface structural element 12 is arranged adjacent to the reinforcing element 6 as a conductive element. The surface structural element 12 is formed as a rib 13 and a groove 15. Additionally or alternatively, at least one structural element 12 may also be arranged in the groove 8.
[0052] In summary, providing an end plate that also serves as a bottom plate of the housing allows the bottom plate of the housing to be omitted, thereby reducing the number of components in the fuel cell stack. This can reduce the overall weight of the fuel cell stack and can also simplify the assembly process of the fuel cell stack due to the reduction in the number of components. Further weight reduction and / or component reduction can be achieved by using an end plate made of an electrically insulating plastic material, which can also allow the insulating plate that is usually provided between the end plate and the terminal plate to be omitted. Since the end plate is electrically insulating, there is no risk of short circuit even if the conductive element of the terminal plate contacts the end plate.
[0053] Reference numerals list
[0054] 1 End plate
[0055] 2 Opening
[0056] 3 End Plate
[0057] 4 Opening
[0058] 6Reinforcement elements
[0059] 8 grooves
[0060] 10 Surface
[0061] 12 Surface structural elements
[0062] 13 ribs
[0063] 14 Protruding connection elements
[0064] 15 Grooves
[0065] 16 Fastening interface
[0066] 18 Shell
[0067] 20 stacks of shrouds
[0068] 22 Top Plate
[0069] 24 Fastening interface
[0070] 26 Sealing element
[0071] 28 Grooves
[0072] 100 fuel cell stack
[0073] 102 fuel cell stack
[0074] 104 Stacking direction
[0075] 106 channels
[0076] 108 Active Area
[0077] 110 terminal board
Claims
1. A fuel cell stack (100), comprising at least: A fuel cell stack (102) having a plurality of unit fuel cells, wherein each unit fuel cell comprises bipolar plates and membrane electrode assemblies alternately stacked along a stacking direction (104), clamping first and second terminal plates (110) of the fuel cell stack (102), wherein the first and second terminal plates (110) are suitable for collecting electrical energy generated by the fuel cell stack (102), first and second end plates (1, 3) clamping first and second terminal plates (110), and A housing (18), wherein the housing (18) comprises at least a bottom plate, a stack cover (20) configured to cover a side of the fuel cell stack (100), and a top plate (22), It is characterized in that The first end plate (1) is configured as a bottom plate of the housing (18) and is provided with at least one protruding connection element (14) which protrudes laterally from the first end plate (1) and is configured to connect the stack casing (20) to the first end plate (1).
2. A fuel cell stack (100) according to claim 1, wherein at least one protruding connecting element (14) includes at least one fastening interface (16) for fixing the stack cover (20) to the at least one protruding connecting element and thereby to the first end plate (1).
3. The fuel cell stack (100) according to claim 1 or 2, wherein the stack cover (20) abuts against the top of at least one protruding connecting element (14) or the side of at least one protruding connecting element (14).
4. The fuel cell stack (100) according to any of the preceding claims, wherein at least one protruding connecting element (14) comprises a groove (28).
5. A fuel cell stack (100) according to any one of the preceding claims, wherein at least one sealing element (26) is provided, and the at least one sealing element (26) is configured to provide a seal between at least one protruding connecting element (14) and the stack cover (20), wherein preferably, the sealing element is arranged in a groove (28).
6. A fuel cell stack according to claim 5, wherein at least one sealing element (26) is arranged at at least one protruding connecting element (14) and / or at the stack cover (20), wherein preferably, at least one sealing element (26) is fixed to the protruding connecting element (14) or the stack cover (20).
7. The fuel cell stack (100) according to any one of the preceding claims, wherein the at least one protruding connection element (14) is configured as a flange extending along the entire periphery of the first end plate (1).
8. A fuel cell stack (100) according to any one of the preceding claims, wherein the first end plate (1) comprises a base and a step portion, wherein the at least one protruding connecting element (14) is arranged at the base, and wherein the step portion comprises input and output ports and / or terminals for operation of the fuel cell stack (100).
9. A fuel cell stack (100) according to any one of the preceding claims, wherein at least the first end plate (1, 3) comprises at least one reinforcing element (6), the at least one reinforcing element (6) being particularly used to reinforce the first end plate (1, 3) to resist deformation forces.
10. The fuel cell stack (100) according to any of the preceding claims, wherein at least the first end plate (1, 3) is made of a plastic material, preferably a fiber reinforced plastic material.
11. A fuel cell stack according to claim 10, wherein at least a first end plate (1, 3) is at least partially in direct contact with a terminal plate (110), and wherein at least one end plate (1, 3) comprises at least one surface structural element (12), wherein the at least one surface structural element (12) is suitable for avoiding any current creepage between the terminal plate (110) and a conductive element of the end plate (1, 3).