Fuel cell stack

Abstract

A fuel cell stack (100) is provided, the fuel cell stack (100) comprising at least a fuel cell stack body (102) having a plurality of unit fuel cells, each unit fuel cell including a bipolar plate and a membrane electrode assembly stacked alternately in a stacking direction (104); a first and second terminal plates (110) sandwiching the fuel cell stack body (102), the first and second terminal plates (110) configured to collect electrical energy generated by the fuel cell stack body (102); and first and second end plates (1, 3) sandwiching a second terminal plate (110); and a housing (18) including at least a bottom plate, a stack enclosure (20) configured to cover the side of the fuel cell stack (100), and a top plate (22), wherein the first end plate (1) is configured as the bottom plate of the housing (18) and has at least one protruding connecting element (14) protruding laterally from the first end plate (1) and configured to connect the stack enclosure (20) to the first end plate (1).

Description

Technical Field

[0001] The present 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 sandwiching the terminal plates. Generally, an insulating plate is provided between each terminal plate and the adjacent end plate to insulate each terminal plate from the adjacent end plate.

[0003] The bipolar plate itself usually consists of at least two conductive metal plates, so-called flow field plates, which are arranged on top of each other and have a flow field for reactants on one side and a flow field for a cooling fluid on the opposite side. Therefore, the cooling fluid flow fields face each other, and the reactant flow fields face the MEA. Each bipolar plate and / or membrane electrode assembly includes an inlet manifold for fuel, an oxidant, and a coolant, and an outlet manifold for fuel, an oxidant, and a coolant. In the assembled stack, each manifold extends through the fuel cell stack body and forms a tubular channel for carrying each flow to / from the fuel cell stack. The flow field of each plate forms an active region where electrical energy is generated, and the active region is arranged between the inlet and outlet manifolds of each unit fuel cell.

[0004] Furthermore, in order to provide contact protection and / or protection from environmental influences such as water and / or dirt, the fuel cell stack is enclosed in a housing including a bottom plate, an upper plate, and side walls, and a seal element is provided between different elements of the housing to achieve a hermetically sealed environment of the fuel cell stack within the housing and ensure safe and stable operation of the fuel cell stack.

[0005] However, due to the number of different components, a typical fuel cell stack can be quite heavy. Furthermore, because the components need to be manufactured and assembled with tight tolerances in some cases to ensure the proper functioning of the fuel cell stack, manufacturing a fuel cell stack is costly and requires a focused effort. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the object of the present invention is to provide a fuel cell stack that is lightweight and can be manufactured in a simple and cost-effective manner. [Means for solving the problem]

[0007] This objective is solved by the fuel cell stack described in claim 1.

[0008] In the following, a fuel cell stack is provided, comprising a fuel cell stack body having a plurality of unit fuel cells. Each unit fuel cell comprises bipolar plates and membrane electrode assemblies stacked alternately in the stacking direction. In this regard, each bipolar plate and / or membrane electrode assembly may include at least a fuel, oxidizer, and coolant inlet manifold and at least a fuel, oxidizer, and coolant outlet manifold. In particular, the manifolds may extend through the fuel cell stack body to form respective tubular channels for supplying their respective flows to and from the fuel cell stack, and each of the unit fuel cells has an active region where electrical energy is generated, the active region located between the inlet and outlet manifolds of each unit fuel cell.

[0009] The fuel cell stack further includes first and second terminal plates flanking the fuel cell stack body, the first and second terminal plates configured to collect electrical energy generated by the fuel cell stack body. The fuel cell stack also includes first and second end plates flanking the fuel cell stack body. In this regard, at least one end plate may include at least one inlet opening and at least one outlet opening, the at least one inlet opening being aligned with one or more inlet channels, and the at least one outlet opening being aligned with one or more outlet channels. For example, the at least one end plate may include at least inlet openings for fuel, oxidizer, and coolant, and at least outlet openings for fuel, oxidizer, and coolant. Furthermore, an insulating plate may be provided between one terminal plate and an adjacent end plate.

[0010] Furthermore, the fuel cell stack includes a housing having at least a bottom plate, a stack enclosure configured to cover the sides of the fuel cell stack, and an upper plate. In particular, the upper plate may be connected to the stack enclosure or formed integrally with the stack enclosure. The stack enclosure may be formed as a hollow box or as a plurality of separate side walls connected to each other to form a hollow box.

[0011] To reduce the number of parts and the complexity of the assembly process of the fuel cell stack, the first end plate is configured as the bottom plate of the housing and includes at least one protruding connecting element that projects laterally from the first end plate and is configured to connect the stack enclosure to the first end plate. This allows the bottom plate of the housing to be omitted, thereby reducing the overall weight and number of parts of the fuel cell stack, simplifying the assembly process, making the finished fuel cell stack lighter, and reducing costs. Conveniently, the second end plate may further be configured as the top plate of the housing. This reduces the number of parts and thereby further reduces the weight of the fuel cell stack.

[0012] Furthermore, the first end plate may also include a plurality of protruding connecting elements. These plurality of protruding connecting elements may be discretely arranged around the outer circumference of the first end plate. This has the advantage of securely fixing the stack enclosure to the first end plate.

[0013] Alternatively, the at least one protruding connecting element may be configured as a flange extending along the entire circumference of the first end plate. This has the advantage of evenly securing the stack enclosure around the first end plate. Furthermore, as will be detailed below, this simplifies the sealing of the housing against external contaminants.

[0014] Furthermore, the at least one protruding connection element may include at least one fastening interface for securing the stack enclosure to the at least one protruding connection element, thereby securing it to the first end plate. This allows for further fastening of the stack enclosure to the first end plate. Preferably, the fastening interface may be configured to removably fasten the stack enclosure to the protruding element. This has the advantage that the housing can be easily removed and then reattached, for example, to access the fuel cell stack for maintenance purposes. The fastening interface may be configured to pressure and / or shape-fit the stack enclosure to the protruding connection element. For example, the fastening interface may be a groove, clamping element, latch, snap tag, lug, and / or hole (e.g., a screw through hole, a screw blind hole, or a through hole through which a fastening element can pass) of the protruding connection element.

[0015] In a further embodiment, at least one sealing element is provided, configured to provide a seal between the at least one protruding connector and the stack enclosure. This ensures the safe and stable operation of the fuel cell stack by creating a sealed environment for the fuel cell stack within the housing. More specifically, the stack enclosure may abut the top or side of the at least one protruding connector. If the stack enclosure abuts the top of the at least one protruding connector, the at least one sealing element can be positioned between the stack enclosure and the protruding connector such that the at least one sealing element is compressed by gravity, thereby improving the seal between the stack enclosure and the end plate, and more specifically, the protruding connector. However, it is also possible to compress the at least one sealing element by other means. For example, fastening elements that secure the stack enclosure to the protruding connector may be further configured to compress the at least one sealing element. In this way, even when the stack enclosure abuts against the side surface of the protruding connecting element, the seal between the stack enclosure and the protruding connecting element can be improved by compressing the at least one sealing element using the fastening element.

[0016] Furthermore, the at least one sealing element is positioned on the at least one protruding connector and / or the stack enclosure. Preferably, the at least one sealing element is fixed to the protruding connector or the stack enclosure. For example, the at least one sealing element may be permanently or removablely fixed to the protruding connector or the stack enclosure. This has the advantage that the at least one sealing element is fixed in place.

[0017] Furthermore, at least one of the sealing elements may be a continuous sealing element. In particular, when combined with the flange, it enables an improved airtight seal of the fuel cell stack within the housing. If an airtight seal of the housing is not required, for example, if only contact protection is needed, it is also possible to provide a plurality of discrete sealing elements. These elements can preferably interact with discrete protruding connecting elements.

[0018] Preferably, the at least one sealing element is positioned in a groove. Furthermore, the at least one sealing element may be fixed by friction to the protruding connecting element, particularly the flange, or the stack enclosure, or be press-fitted, bonded with adhesive, and / or molded. For example, the at least one sealing element may have a U-shape that can be attached to the edge of the stack enclosure. Alternatively, the at least one sealing element may be molded, clamped, and / or bonded.

[0019] Furthermore, the at least one protruding connecting element may include a groove. The groove may be configured to accommodate a portion of the stack enclosure, such as the edge of the stack enclosure, and / or the at least one sealing element. This has the advantage that the position of the stack enclosure and / or the position of the at least one sealing element on the first end plate can be adjusted and / or fixed. Preferably, the groove may be deep enough to also accommodate the at least one sealing element. This can improve the airtight seal of the fuel cell stack within the housing. Alternatively, the groove may accommodate only the at least one sealing element.

[0020] In a further embodiment, the end plate includes a base portion and a stepped portion, the at least one protruding connecting element being positioned on the base portion, and the stepped portion including 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 an inlet opening for reactants and / or coolant, an outlet opening for reactants and / or coolant, at least one output terminal for the generated electrical energy, and / or at least one terminal for monitoring the fuel cell stack. Preferably, the stepped portion is recessed by a predetermined amount relative to the base portion. This ensures sufficient space between the stack enclosure and components of the fuel cell stack positioned on the stepped portion, such as compression elements that will be provided to compress the fuel cell stack.

[0021] Preferably, at least the first end plate includes at least one reinforcing element to reinforce the first end plate, particularly against 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 metal tube. This improves the resistance of the first end plate to deformation forces. For example, the at least one reinforcing element may be hollow or solid. The at least one reinforcing element may also be a profiled element and / or may include an opening into which the material forming the end plate can enter.

[0022] Additionally or alternatively, the at least one reinforcing element may be a frame having at least one bar with a circular, triangular, rectangular, elliptical, or polygonal cross-section. Preferably, the at least one reinforcing element is positioned on the stepped portion of the first end plate. Furthermore, the reinforcing element may also be configured to function as an anchor point for securing the compression element, which is 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] In a further embodiment, at least the first end plate is made of an electrically insulating material. By making the first end plate from an electrically insulating material, the first end plate can be conveniently positioned in at least partially direct contact with the terminal plate, eliminating the need for an additional insulating plate. This further reduces the number of parts, and consequently simplifies the assembly process by reducing the number of parts that need to be assembled. Since the end plate itself is made at least partially from an electrically insulating material, there is no risk of short circuit even if the terminal plate is in direct contact with the end plate.

[0024] Additionally or alternatively, the at least one end plate may be coated with an electrical insulating material at least partially in the area in direct contact with the adjacent terminal plate. For example, the end plate may be made of metal coated at least partially with an electrical insulating material. This has the advantage that the metal provides the necessary strength and / or stability required for the end plate, while the electrical insulating material forms a coating that provides electrical insulation.

[0025] Furthermore, the plastic material may be a fiber-reinforced plastic material. Fiber-reinforced plastic materials have the advantage of providing greater strength and / or stability than plastic materials while also having electrical insulation properties. For example, the fiber-reinforced plastic material may be a glass fiber-reinforced molding material, a glass fiber-reinforced epoxy, a glass fiber-reinforced polyester, and / or a glass fiber-reinforced phenolic resin molding material.

[0026] Preferably, the electrical insulation material is a moldable material, and preferably the at least one end plate is molded. Advantageously, the end plate may be formed by a molding process such as injection molding. This enables a cost-effective manufacturing process. For example, the electrical insulation material may be a composite plastic, a thermosetting composite material, and / or a phenolic plastic. Thermosetting plastic materials have the advantage of not changing shape when exposed to heat.

[0027] Preferably, the at least one end plate includes a recess formed on the surface of the end plate facing the adjacent terminal plate, and the dimensions of the recess are sized to accommodate the terminal plate. This can reduce the overall height of the fuel cell stack. Furthermore, the depth of the recess can be designed such that the overall height of the terminal plate can be accommodated within the recess. Alternatively, the depth of the recess may be designed such that only a portion of the height of the terminal plate is incorporated into the recess.

[0028] Furthermore, the dimensions and / or depth of the recess may be further configured and sized such that the recess incorporates a heating element configured to heat the fuel cell stack body. The heating element may be configured to supply thermal energy to the fuel cell stack or a part of the fuel stack to compensate for heat loss generated during operation of the fuel cell stack or to heat the fuel cell stack during startup. By also disposing the heating element in the recess of the end plate, the height of the fuel cell stack is further reduced.

[0029] According to a further embodiment, at least the first end plate is in at least partial direct contact with the terminal plate, and the at least one end plate includes at least one surface structure element configured to avoid current leakage between the terminal plate and the conductive portion of the end plate. Despite the end plate being electrically insulated, there is a possibility that current leakage may occur. Leakage current, i.e., leakage current, is an uncontrollable and undesirable current that flows along the surface of the insulating material between two conductors. The shortest path for these currents to flow along the surface of the insulating material is called the creepage distance. These fault currents on the surface of the insulating material can cause changes in the insulating material over time.

[0030] For example, the at least one surface structure element may be disposed adjacent to the conductive element. Preferably, the at least one surface structure includes at least one rib and / or groove, and / or a plurality of ribs and / or grooves. Additionally or alternatively, the at least one structural element is disposed around the at least one end plate and / or in a recess formed in the at least one end plate. The conductive element may be the terminal plate, a reinforcing element, and / or other metal parts. Also, there may be provided one or more surface structure elements on the at least one end plate.

[0031] Further preferred embodiments are provided not only in the specification and drawings but also in the dependent claims. In this regard, elements described or illustrated in combination with other elements may exist alone or in combination with other elements without departing from the scope of protection.

[0032] Preferred embodiments of the present invention will be described below with reference to the drawings, which are for illustrative purposes only and are not intended to limit the scope of protection. The scope of protection is defined solely by the appended claims. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic perspective exploded view of a fuel cell stack according to one embodiment. [Figure 2] Figure 1 is a schematic perspective view of the end plate of the fuel cell stack. [Figure 3] This is a side view of a fuel cell stack. [Modes for carrying out the invention]

[0034] In the following, elements that are identical or function similarly are indicated by the same reference number.

[0035] Figures 1-3 show a fuel cell stack 100 according to one embodiment. The fuel cell stack includes a fuel cell stack body 102 comprising a plurality of unit fuel cells. Each unit fuel cell includes bipolar plates and membrane electrode assemblies stacked alternately in the stacking direction 104, and each bipolar plate and / or membrane electrode assembly may include at least a fuel, oxidizer, and coolant inlet manifold and at least a fuel, oxidizer, and coolant outlet manifold. The manifolds can extend through the fuel cell stack body 102 to form respective tubular channels 106 for supplying their respective flows to and from the fuel cell stack 100. Each unit fuel cell has an active region 108 where electrical energy is generated, and the active region 108 is located between the inlet and outlet manifolds of each unit fuel cell.

[0036] The fuel cell stack 100 further includes first and second terminal plates 110 that sandwich the fuel cell stack body 102. The first and second terminal plates 110 are configured to collect electrical energy generated by the fuel cell stack body 102 within the active region 108. The fuel cell stack also includes a first end plate 1 and a second end plate 3 that sandwich the fuel cell stack body 102.

[0037] Furthermore, the fuel cell stack 100 includes a housing 18 (Figure 3) which can function as contact and / or environmental protection. The housing 18 includes a stack enclosure 20 configured to cover the sides of the fuel cell stack 100 and an upper plate 22. The bottom plate of the housing 18 is formed by a first end plate 1, as can be seen in Figure 3. The upper plate 22 is connected to the stack enclosure 20 by fastening interfaces 24, and the stack enclosure 20 is formed by a plurality of interconnected independent side walls 20-1, 20-2 to form a hollow box. Alternatively, the stack enclosure 20 may be formed as a hollow box, and / or the upper plate 22 may be formed integrally with the stack enclosure 20, or the second end plate 3 may be configured as the upper plate 20.

[0038] To also function as a bottom plate for the housing 18, the end plate 1 includes a protruding connecting element 14 that projects laterally from the first end plate 1 and is configured to connect the housing 18 to the first end plate 1. In the above embodiment, the protruding connecting element is a flange 14 surrounding the outer circumference of the end plate 1. Alternatively, particularly when only contact protection is required, the first end plate 1 may include a plurality of independent protruding connecting elements, which are arranged around the outer circumference of the first end plate 1.

[0039] In the embodiment described above, the housing 18 abuts against the upper part of the flange 14, as can be seen in Figure 3. To attach the housing 18 to the end plate 1, the flange 14 has a plurality of fastening interfaces 16 for securing the housing 18 to the end plate 1. In the illustrated embodiment, the fastening interfaces 16 are blind holes provided in the flange 14 in the stacking direction 104. However, the fastening interfaces 16 may also be through holes through which fastening elements can be inserted or through holes through which screws can pass. Alternatively, the stack enclosure 20 may abut against the side surface of the flange 14. In this case, the blind holes serving as fastening interfaces may be provided on the side surface of the flange 14 perpendicular to the stacking direction 104.

[0040] To ensure an airtight seal of the fuel cell stack, a continuous sealing element 25 is provided to seal between the flange 14 and the housing 18 or stack enclosure 20. In the illustrated embodiment, the sealing element 26 is positioned in a groove 28 provided in the flange 14. Alternatively, the sealing element 26 may be fixed to the protruding connecting element 14 or the stack enclosure 20. For example, the sealing element 26 may be fixed by friction, press-fitted, attached with adhesive, molded, clamped, and / or bonded. As can be seen in Figure 3, the stack enclosure 20 abuts against the top of the flange 14, so that the sealing element 26 is compressed by the weight of the stack enclosure 20 due to gravity even before the stack enclosure 20 is fastened to the first end plate 1.

[0041] As can be seen, the end plate 1 has a T-shape with a base portion and a stepped portion formed by a flange 14, the stepped portion including input and output ports and / or terminals for the operation of the fuel cell stack 100, for example, input and output openings 2a, 2b, 2c, 4a, 4b, 4c. More specifically, the first end plate 1 has fuel, oxidizer and coolant inlet openings 2a, 2b, 2c and fuel, oxidizer and coolant outlet openings 4a, 4b, 4c.

[0042] As shown in Figure 1, the inlet openings 2a, 2b, 2c and outlet openings 4a, 4b, 4c are aligned with the inlet and outlet channels 106 that extend through the fuel cell stack body 102, supplying their respective flows to and from the fuel cell stack 100. In this case, the second end plate 3 is configured to terminate the inlet and outlet channels 106. Alternatively, the inlet openings 2a, 2b, 2c and outlet openings 4a, 4b, 4c may be divided between the first and second end plates 1 and 3.

[0043] As can be seen from Figure 1, the first end plate 1 and the second end plate 3 are in direct contact with the terminal plate 110, at least partially. To avoid short circuits between the terminal plate 110 and the first and second end plates 1 and 3, the end plates 1 and 3 are made of a plastic material to electrically insulate them. Alternatively, an insulating plate made of an electrically insulating material may be provided between the end plates 1 and 3 and the terminal plate 110.

[0044] The plastic material forming the first end plate 1 may be a moldable plastic material, and the end plate 1 can be formed by a molding process such as injection molding.

[0045] Furthermore, in the illustrated embodiment, the end plate 1 includes three reinforcing elements 6 embedded in the plastic material. However, any other number of reinforcing elements 6 may be selected depending on the dimensions of the end plate 1 and / or the expected loads that the end plate 1 will be subjected to. As can be seen in Figure 3, the reinforcing elements 6 are cylindrical rods extending through the end plate 1. For example, the reinforcing elements 6 may be overmolded with an electrically insulating material. Alternatively, the reinforcing elements 6 may be inserted into the end plate 1.

[0046] Alternatively, the reinforcing element 6 may form a frame having metal rods with circular, triangular, rectangular, elliptical, or polygonal cross-sections. Depending on the dimensions of the end plate 1 and / or the expected load on the end plate 1, the reinforcing element may be a hollow element or a solid element. The reinforcing element 6 may also be profiled and / or may include openings into which the material forming the end plate 1 can be inserted. Of course, different types of reinforcing elements 6 may be used for a single end plate 1.

[0047] The end plate 1 shown in this embodiment is made of a plastic material, which eliminates the need for an additional insulating plate between the end plate 1 and the adjacent terminal plate 110. As can be seen further in the illustrated embodiment, the end plate 1 includes a recess 8 formed in the surface 10 of the end plate 1 that faces the adjacent terminal plate 110. The dimensions of the recess 8 are determined to accommodate the terminal plate 110. For example, the depth of the recess 8 may be designed so that the entire height of the terminal plate 110 can be accommodated in the recess 8. Alternatively, the depth of the recess 8 may be such that only a portion of the height of the terminal plate 110 is incorporated into the recess 8.

[0048] Furthermore, the end plate 1 includes surface structural elements 12 configured to avoid current leakage between conductive elements such as the terminal plate 110 and the conductive portion of the end plate 1. For example, the surface structural elements 12 are positioned adjacent to the reinforcing elements 6, which are conductive elements. The surface structural elements 12 are formed as ribs 13 and grooves 15. Additionally or alternatively, at least one structural element 12 may be positioned in the recess 8.

[0049] In summary, by providing an end plate that also functions as the bottom plate of the housing, the bottom plate of the housing can be omitted, resulting in a reduction in the number of parts in the fuel cell stack. This reduces the overall weight of the fuel cell stack and simplifies the assembly process of the fuel cell stack due to the reduction in the number of parts. Further weight and / or part reductions can be achieved by using an end plate made of electrically insulating plastic material, which also eliminates the insulating plate that is normally placed between the end plate and the terminal plate. Because the end plate is electrically insulated, there is no risk of short circuits even if the conductive elements of the terminal plate are in contact with the end plate. [Explanation of Symbols]

[0050] 1 End plate 2 openings 3 End Plates 4 openings 6. Reinforcement elements 8 recesses 10 surface 12 Surface structure elements 13 Ribs 14. Protruding connection element 15 groove 16. Fastening Interface 18 Housing 20 Stackable Enclosures 22 Top plate 24 Fastening Interfaces 26 Seal elements 28 Groove 100 fuel cell stacks 102 Fuel cell stack body 104 Lamination direction 106 channels 108 Active Area 110 Terminal Plate

Claims

1. A fuel cell stack body (102) comprising a plurality of unit fuel cells, each including bipolar plates and membrane electrode assemblies, which are alternately stacked in the stacking direction (104), A terminal plate (110) including a first terminal plate and a second terminal plate, which sandwiches the fuel cell stack body (102) and is configured to collect electrical energy generated by the fuel cell stack body (102), The end plates (1, 3) include a first end plate (1) adjacent to the first terminal plate and a second end plate (3) adjacent to the second terminal plate, A housing (18) including at least a bottom plate, a stack enclosure (20) configured to cover the sides of the fuel cell stack (100), and an upper plate (22), A fuel cell stack (100) comprising at least the following: The first end plate (1) is configured as the bottom plate of the housing (18) and includes at least one protruding connecting element (14) that protrudes laterally from the first end plate (1) and is configured to connect the stack enclosure (20) to the first end plate (1). A fuel cell stack characterized in that the portion of the first end plate excluding the protruding connecting element (14) is a protruding portion that can penetrate into the interior of the stack enclosure (20), and anchor points for fixing a compression element capable of compressing a plurality of the unit fuel cells are formed on the protruding portion.

2. The fuel cell stack according to claim 1, wherein at least one of the protruding connecting elements (14) includes at least one fastening interface (16) for fixing the stack enclosure (20) to the protruding connecting element (14) and thereby fixing it to the first end plate (1).

3. The fuel cell stack according to claim 1 or 2, wherein the stack enclosure (20) abuts against the upper part of at least one of the protruding connecting elements (14) or the side surface of at least one of the protruding connecting elements (14).

4. The fuel cell stack according to claim 1, wherein at least one of the protruding connecting elements (14) includes a groove (28).

5. The fuel cell stack according to claim 1, further comprising at least one sealing element (26) configured to provide a seal between at least one of the protruding connecting elements (14) and the stack enclosure (20), wherein the sealing element (26) is positioned in a groove (28).

6. At least one of the sealing elements (26) is located on at least one of the protruding connecting elements (14) and / or the stack enclosure (20), The fuel cell stack according to claim 5, wherein at least one of the sealing elements (26) is fixed to the protruding connecting element (14) or the stack enclosure (20).

7. The fuel cell stack according to claim 1, wherein at least one of the protruding connecting elements (14) is configured as a flange extending along the entire circumference of the first end plate (1).

8. The first end plate (1) includes a base portion and a stepped portion, At least one of the protruding connecting elements (14) is positioned on the base portion, The fuel cell stack according to claim 1, wherein the stepped portion includes input and output ports and / or terminals for the operation of the fuel cell stack (100).

9. The fuel cell stack according to claim 1, wherein the end plates (1, 3) include at least one reinforcing element (6) for reinforcing the end plates (1, 3) against deformation forces.

10. The fuel cell stack according to claim 1, wherein the end plates (1, 3) are made of a plastic material or a fiber-reinforced plastic material.

11. The end plates (1, 3) are in at least partial direct contact with the terminal plate (110), The fuel cell stack according to claim 10, wherein at least one of the end plates (1, 3) includes at least one surface structure element configured to avoid current leakage between the terminal plate (110) and the conductive elements of the end plate (1, 3).

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