Separator assembly for fuel cell and Fuel cell stack including the same

Abstract

The present invention relates to a separator assembly for a fuel cell that is connected by a mechanical structure and a fuel cell stack including the same. A fuel cell separator assembly according to one embodiment of the present invention is a fuel cell separator assembly comprising a pair of separators, comprising: a first separator in which a tunnel-shaped fastening portion is formed at a plurality of points in a periphery region; and a second separator in which an insertion portion is formed at a position corresponding to the fastening portion of the first separator in the periphery region and is inserted into the fastening portion, wherein the insertion portion of the second separator is inserted into the fastening portion of the first separator and the first separator and the second separator are assembled.

Description

Technology Field

[0001] The present invention relates to a separator assembly for a fuel cell and a fuel cell stack including the same, and more specifically, to a separator assembly for a fuel cell that is fastened by a mechanical structure and a fuel cell stack including the same. Background Technology

[0003] Fuel cells are a type of power generation device that converts the chemical energy contained in fuel into electrical energy through an electrochemical reaction within a stack. They can be used not only to supply power for industrial, residential, and vehicle use, but also to power small electronic products such as portable devices, and their scope of application is gradually expanding as a high-efficiency clean energy source.

[0004] Figure 1 is a diagram showing the configuration of a typical fuel cell stack.

[0005] As can be seen in FIG. 1, a typical fuel cell stack has a membrane-electrode assembly (MEA) located at the innermost part, and this membrane-electrode assembly (10) is composed of a polymer electrolyte membrane (11) capable of transporting hydrogen cations (protons), and catalyst layers coated on both sides of the electrolyte membrane to allow hydrogen and oxygen to react, namely an anode (12) and a cathode (13).

[0006] Additionally, a pair of gas diffusion layers (20, GDL) are laminated on the outer part of the membrane electrode assembly (10), that is, the outer part where the fuel electrode (12) and the air electrode (13) are located, and a pair of separator plates (30) with a flow field formed to supply fuel and discharge water generated by the reaction are positioned on the outer side of the gas diffusion layers (20) with a gasket (40) in between, and an end plate (50) is attached to the outermost part to support and fix each of the above components.

[0007] At this time, a pair of separator plates (30) are divided into an anode separator plate (31) placed at the fuel electrode (anode) and a cathode separator plate (32) placed at the air electrode (cathode).

[0008] Meanwhile, the fuel cell stack is formed by stacking a plurality of unit cells, wherein the anode separator (31) placed in one of the unit cells is stacked so as to be in contact with the cathode separator (32) of the unit cell adjacent to the one of the unit cells.

[0009] Accordingly, to smoothly carry out the stacking process of the unit cells and to maintain the alignment of each unit cell, the cathode separator (32) and the anode separator (31) of adjacent unit cells, which are arranged to be butted against each other, are integrated to stack the unit cells.

[0010] Figure 2 is a drawing showing a conventional separator plate integrated by welding.

[0011] As can be seen in FIG. 2, a conventional separator (30) has a reaction surface formed in the central region where a membrane electrode assembly is disposed, and a plurality of inlet manifolds and outlet manifolds are formed in the regions on both sides of the reaction surface. At this time, to seal the reaction surface, inlet manifolds and outlet manifolds, a gasket (40) is used to surround the region where the reaction surface, inlet manifolds and outlet manifolds are formed.

[0012] Meanwhile, a method for integrating the anode separator plate (31) and the cathode separator plate (32) of adjacent unit cells was adopted by spot welding a predetermined point among the edge regions of the anode separator plate (31) and the cathode separator plate (32) that are butted against each other. At this time, the welding point was indicated as the welding point (W).

[0013] Figure 3 is an enlarged view of part "A" of Figure 2.

[0014] As can be seen in FIG. 3, when a pair of separator plates (30), namely the anode separator plate (31) and the cathode separator plate (32), are facing each other, the edges are separated from each other by the channels formed in each.

[0015] However, due to the nature of spot welding, the welding surfaces must be in very close contact. Therefore, in order to spot weld the anode separator (31) and the cathode separator (32), a welding surface (32a) is formed by bending the welding point of the cathode separator (32) so that it comes into contact with the anode separator (31).

[0016] In addition, since it is important to remove metal burrs that inevitably occur during the manufacturing process of the anode separator (31) and cathode separator (32), a lot of time and cost is invested in trimming process management, and a cleaning process is essential before welding.

[0017] Additionally, the anode separator (31) and the cathode separator (32) are subject to a springback phenomenon due to the characteristics of the press process, and the inevitable springback phenomenon increases the failure rate of contact with the weld surface (32a).

[0018] Thus, the poor welding surface contact caused by phenomena such as metal burrs and springback during the joining process of the anode separator (31) and the cathode separator (32) became a major factor in lowering the yield of the separator.

[0019] Furthermore, since welding is fundamentally a technique that applies the principle of locally melting and joining metals, if both welding strength and position are not properly controlled, holes may form in the affected area due to the melting of the metal. This causes airtightness failures in the flow paths for hydrogen, air, and cooling water, which are critical components handled by the separator.

[0021] The content described above as background technology is intended only to help understand the background of the present invention and should not be construed as an acknowledgment that it constitutes prior art already known to those skilled in the art. Prior art literature

[0023] Registered Patent Publication No. 10-0783423 (December 3, 2007) The problem to be solved

[0024] The present invention provides a fuel cell separator assembly connected by a mechanical structure and a fuel cell stack including the same. means of solving the problem

[0026] A fuel cell separator assembly according to one embodiment of the present invention is a fuel cell separator assembly comprising a pair of separators, comprising: a first separator in which a tunnel-shaped fastening portion is formed at a plurality of points in a periphery region; and a second separator in which an insertion portion is formed at a position corresponding to the fastening portion of the first separator in the periphery region and is inserted into the fastening portion, wherein the insertion portion of the second separator is inserted into the fastening portion of the first separator and the first separator and the second separator are assembled.

[0027] The fastening portion of the first separator plate is characterized by being bent and protruding in a direction facing the second separator plate, and at least one of the two ends is opened to form an inlet.

[0028] The insertion portion of the second separator plate is characterized by being bent and protruding in a direction facing the first separator plate, and extending so as to be inserted into the inlet.

[0029] The fastening portion of the first separator plate is formed along the long axis direction of the first separator plate, and a pair of inlets are formed at both ends based on the long axis direction, and the pair of inlets are connected to each other.

[0030] The insertion portion of the second separator is formed along the long axis direction of the second separator, and at one end, an extension portion is formed that is bent while extending integrally with the main body of the second separator based on the long axis direction, and at the other end, a separation portion is formed that is spaced apart from the main body of the second separator, so that the insertion portion is inserted into the inlet of the fastening portion through the separation portion.

[0031] The fastening portion of the first separator plate is formed along the short axis direction of the first separator plate, and a pair of inlets are formed at both ends based on the short axis direction, and the pair of inlets are connected to each other.

[0032] The insertion portion of the second separator is formed along the short axis direction of the second separator, and at one end, an extension portion is formed that is bent while extending integrally with the main body of the second separator based on the short axis direction, and at the other end, a separation portion is formed that is spaced apart from the main body of the second separator, so that the insertion portion is inserted into the inlet of the fastening portion through the separation portion.

[0033] The fastening portion of the first separator is formed at least two points each in the border areas on both sides based on the short axis direction of the first separator, and the insertion portion of the second separator is formed corresponding to the point where the fastening portion is formed.

[0034] The direction of the insertion part inserted into the fastening part along the same major axis is characterized by being the same direction.

[0035] The insertion part inserted into the fastening part along the same major axis is characterized by having opposite directions.

[0036] The direction of the insertion part inserted into the fastening part on the same short axis is characterized by being the same direction.

[0037] The insertion part inserted into the fastening part on the same axis is characterized by having opposite directions.

[0039] Meanwhile, a fuel cell stack according to one embodiment of the present invention is a fuel cell stack formed by stacking a plurality of fuel cell cells, each comprising a membrane electrode assembly, a pair of gas diffusion layers, a first separator, and a second separator, wherein a tunnel-shaped fastening portion is formed at a plurality of points in the edge region of the first separator, and an insertion portion is formed in the edge region of the second separator at a position corresponding to the fastening portion of the first separator, into which the fastening portion is inserted, and the first separator and the second separator are assembled by inserting the insertion portion of the second separator into the fastening portion of the first separator. Effects of the invention

[0041] According to an embodiment of the present invention, by applying a method of fastening with a mechanical structure instead of a welding method during the process of assembling a pair of separator plates, the welding process itself is eliminated, thereby reducing process costs and resolving issues such as ion leaching from the separator plates due to welding and reduced durability caused by corrosion resistance.

[0042] In addition, the stacking defect rate during the separator stacking process caused by welding defects in the separator can be reduced, and accordingly, the defect rate of the fuel cell stack can also be expected to be reduced. Brief explanation of the drawing

[0044] Figure 1 is a diagram showing the configuration of a typical fuel cell stack, and FIG. 2 is a drawing showing a conventional separator plate integrated by welding, and FIG. 3 is an enlarged view of section "A" of FIG. 2, and FIG. 4 is a drawing showing a separator assembly for a fuel cell according to one embodiment of the present invention, and FIG. 5 is a drawing showing a first separator of a fuel cell separator assembly according to one embodiment of the present invention, and FIGS. 6a and 6b are drawings showing a second separator of a fuel cell separator assembly according to an embodiment of the present invention, and FIG. 7 is a drawing showing the assembled state of a separator assembly for a fuel cell according to one embodiment of the present invention, and FIG. 8 is an enlarged view of section "B" of FIG. 7, and FIGS. 9 and 10 are drawings showing the fastening direction of a separator assembly for a fuel cell according to an embodiment of the present invention, and FIG. 11 is a drawing showing a first separator of a fuel cell separator assembly according to another embodiment of the present invention, and FIG. 12 is a drawing showing a second separator of a fuel cell separator assembly according to another embodiment of the present invention, and FIGS. 13 and 14 are drawings showing the fastening direction of a separator assembly for a fuel cell according to another embodiment of the present invention. Specific details for implementing the invention

[0045] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms; these embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Identical reference numerals in the drawings refer to identical elements.

[0047] A fuel cell stack according to one embodiment of the present invention improves the assembly structure and method of separator plates facing each other while maintaining the conventional fuel cell stack configuration shown in FIG. 1. Specifically, a pair of separator plates facing each other in adjacent cells each have a fastening part and an insertion part formed for mechanical fastening to each other, and the pair of separator plates are assembled by fastening the insertion part to the fastening part. Accordingly, a welding process for joining the pair of separator plates can be eliminated.

[0048] Accordingly, a fuel cell stack according to one embodiment of the present invention comprises a membrane electrode assembly (10) as shown in FIG. 1, a pair of gas diffusion layers (20), an anode separator (31, hereinafter referred to as "first separator (100)"), and a cathode separator (32, hereinafter referred to as "second separator (200)") to form a unit cell, and several unit cells are connected in series. Accordingly, the first separator (100) formed in one cell is arranged facing each other with the second separator (200) formed in the adjacent cell. In this embodiment, the first separator (100) and the second separator (200) facing each other are assembled into a mechanical structure to form a separator assembly.

[0049] In the present invention, if a fastening part (110) is formed on one of the separator plates and an insertion part (210) is formed on another separator plate, the formation location is not specified as an anode separator plate and a cathode separator plate.

[0050] Accordingly, in the following description, among the pair of separator plates forming the separator plate assembly, the anode separator plate is referred to as the first separator plate (100), and the cathode separator plate is referred to as the second separator plate (200).

[0051] Further explanation regarding the separator assembly.

[0052] FIG. 4 is a drawing showing a separator assembly for a fuel cell according to one embodiment of the present invention, FIG. 5 is a drawing showing a first separator of a separator assembly for a fuel cell according to one embodiment of the present invention, and FIG. 6a and FIG. 6b are drawings showing a second separator of a separator assembly for a fuel cell according to one embodiment of the present invention.

[0053] As illustrated in the drawing, a fuel cell separator assembly according to one embodiment of the present invention comprises a first separator (100) in which a tunnel-shaped fastening portion (110) is formed at a plurality of points in a border area; and a second separator (200) in which an insertion portion (210) is formed at a position corresponding to the fastening portion (110) of the first separator (100) in the border area, and which is inserted into the fastening portion (110). Thus, the insertion portion (210) of the second separator (200) is inserted into the fastening portion (110) of the first separator (100), and the first separator (100) and the second separator (200) are assembled.

[0054] At this time, the first separator (100) and the second separator (200) have a reaction surface formed in the central region where a membrane electrode assembly is disposed, and a plurality of inlet manifolds and outlet manifolds are formed in the regions on both sides of the reaction surface based on the long axis direction. At this time, to seal the reaction surface, inlet manifolds, and outlet manifolds, a gasket is used to surround the region where the reaction surface, inlet manifolds, and outlet manifolds are formed.

[0055] And, the positions of the reaction surface, inlet manifold, and outlet manifold of the first separator plate (100) and the positions of the reaction surface, inlet manifold, and outlet manifold of the second separator plate (200) are formed at positions corresponding to each other.

[0057] The fastening portion (110) formed on the first separating plate (100) is bent and protruded in a direction facing the second separating plate (200), and at least one end is opened to form an inlet (111, 112). Thus, the fastening portion (110) is formed in a tunnel shape with both ends open or in a tunnel shape with one end open. In this embodiment, the fastening portion (110) formed on the first separating plate (100) is implemented in a tunnel shape with both ends open.

[0058] At this time, the open end of the fastening part (110) formed on the first separator plate (100) is referred to as the first inlet (111), and the other open end of the fastening part (110) is referred to as the second inlet (112).

[0059] And, the fastening portion (110) of the first separator plate (100) is formed along the long axis direction of the first separator plate (100), so that a first inlet (111) is formed at one end and a second inlet (112) is formed at the other end based on the long axis direction. Thus, the first inlet (111) and the second inlet (112) are connected to each other.

[0060] Meanwhile, the cross-section of the fastening part (110) is preferably formed in the shape of a parallelogram, with the length of the upper side (L2) being relatively short and the length of the lower side (L1) being relatively long, and the upper and lower sides being parallel (L1 > L2).

[0062] The insertion portion (210) formed in the second separator plate (200) is bent and extended so as to be inserted into the inlet (111, 112) while protruding in a direction facing the first separator plate (100).

[0063] To elaborate, the insertion portion (210) of the second separator plate (200) is formed along the long axis direction of the second separator plate (200), so that an extension portion (212) is formed that is bent and extends integrally with the main body of the second separator plate (200) at one end relative to the long axis direction, and a separation portion (211) is formed that is spaced apart from the main body of the second separator plate (200) at the other end. Thus, the cross-section of the insertion portion (210) formed in the second separator plate (200) is formed in an approximate "L" shape. Among the outer surface of the second separator plate (200), that is, the four sides, the remaining two sides, excluding the side where the extension portion (212) and the separation portion (211) are formed, are also spaced apart from the main body of the second separator plate (200) in the same way as the separation portion (211).

[0065] The assembly state of the first separator plate (100) and the second separator plate (200) configured as described above will be explained with reference to the drawings.

[0066] FIG. 7 is a drawing showing the assembled state of a separator assembly for a fuel cell according to one embodiment of the present invention, and FIG. 8 is an enlarged drawing of part "B" of FIG. 7.

[0067] As shown in the drawing, the second separator (200) is moved along the long axis direction while the gap portion (211) of the insertion portion (210) formed on the second separator (200) is inserted into the second inlet (112) of the fastening portion (110) formed on the first separator (100). Thus, when the extension portion (212) of the insertion portion (210) formed on the second separator (200) comes into contact with the second inlet (112) of the fastening portion (110) formed on the first separator (100), the assembly is completed as the gap portion (211) of the insertion portion (210) formed on the second separator (200) is positioned at the first inlet (111) of the fastening portion (110) formed on the first separator (100), as shown in FIG. 8.

[0069] Meanwhile, the fastening direction of the fastening portion (110) formed on the first separator plate (100) and the insertion portion (210) formed on the second separator plate (200) can be varied to facilitate the fastening process of the first separator plate (100) and the second separator plate (200) or to strengthen the fastening force of the first separator plate (100) and the second separator plate (200).

[0070] FIGS. 9 and FIGS. 10 are drawings showing the fastening direction of a separator assembly for a fuel cell according to one embodiment of the present invention.

[0071] As shown in FIG. 9, the direction of the insertion part (210) inserted into the fastening part (110) on the same long axis line can be set to be the same direction to facilitate the fastening process of the first separator plate (100) and the second separator plate (200).

[0072] At this time, the formation direction of the spacing portion (211) and the extension portion (212) of the insertion portion (210) formed on the same long axis line in the second separator plate (200) is formed in the same way. Thus, the fastening portion (110) and the insertion portion (210) are assembled in the same direction at multiple assembly points (C1) where they are fastened.

[0073] Thus, as shown in Fig. 9, a plurality of insertion parts (210) can be assembled to a plurality of fastening parts (110) in a single operation at a plurality of assembly points (C1).

[0074] Meanwhile, as shown in FIG. 10, the direction of the insertion part (210) inserted into the fastening part (110) on the same long axis line can be set in opposite directions to strengthen the fastening force between the first separator plate (100) and the second separator plate (200).

[0075] At this time, the formation directions of the separation portion (211) and the extension portion (212) of the insertion portion (210) formed on the same long axis line in the second separator plate (200) are formed in opposite directions. Thus, the assembly points where the fastening portion (110) and the insertion portion (210) are fastened, namely assembly points C1 and C2 shown in FIG. 10, are assembled in opposite directions.

[0076] In order to assemble in opposite directions at assembly points C1 and C2 as shown in Fig. 10, first, an insertion part (210) is inserted into the fastening part (110) at assembly point (C1), and then, utilizing the elasticity of the second separating plate (200), the second separating plate (200) is bent in the long axis direction, and then an insertion part (210) is inserted into the fastening part (110) at assembly point (C2).

[0078] Meanwhile, when assembling the first separator plate (100) and the second separator plate (200), the assembly is not limited to the long axis direction; the first separator plate (100) and the second separator plate (200) can be assembled in the short axis direction by changing the shape of the fastening part (110) and the insertion part (210).

[0079] FIG. 11 is a drawing showing a first separator of a fuel cell separator assembly according to another embodiment of the present invention, and FIG. 12 is a drawing showing a second separator of a fuel cell separator assembly according to another embodiment of the present invention.

[0080] As shown in FIG. 11, the fastening portion (110) of the first separator plate (100) is formed along the short axis direction of the first separator plate (100), so that a third inlet (113) is formed at one end with respect to the short axis direction and a fourth inlet (114) is formed at the other end. Thus, the third inlet (113) and the fourth inlet (114) are connected to each other.

[0081] Additionally, as illustrated in FIG. 12, the insertion portion (210) of the second separator plate (200) is formed along the short axis direction of the second separator plate (200), so that at one end, an extension portion (214) is formed that is bent while extending integrally with the main body of the second separator plate (200) with respect to the short axis direction, and at the other end, a separation portion (213) is formed that is spaced apart from the main body of the second separator plate (200). In this case as well, the cross-section of the insertion portion (210) formed on the second separator plate (200) is formed in an approximate "L" shape.

[0083] In addition, the first separator plate (100) and the second separator plate (200) assembled in the short direction can also have their fastening directions varied by changing the fastening direction of the fastening part (110) formed on the first separator plate (100) and the insertion part (210) formed on the second separator plate (200) to facilitate the fastening process of the first separator plate (100) and the second separator plate (200) or strengthen the fastening force of the first separator plate (100) and the second separator plate (200).

[0084] FIGS. 13 and 14 are drawings showing the fastening direction of a separator assembly for a fuel cell according to another embodiment of the present invention.

[0085] As shown in FIG. 13, the direction of the insertion part (210) inserted into the fastening part (110) on the same short axis can be set to be the same direction to facilitate the fastening process of the first separator plate (100) and the second separator plate (200).

[0086] At this time, the formation direction of the separation portion (213) and the extension portion (214) of the insertion portion (210) formed on the same short line in the second separator plate (200) is formed in the same way. Thus, the fastening portion (110) and the insertion portion (210) are assembled in the same direction at multiple assembly points (C3) where they are fastened.

[0087] Thus, as shown in Fig. 13, a plurality of insertion parts (210) can be assembled to a plurality of fastening parts (110) in a single operation at a plurality of assembly points (C3).

[0088] Meanwhile, as shown in FIG. 14, the direction of the insertion part (210) inserted into the fastening part (110) on the same short axis can be set in opposite directions to strengthen the fastening force between the first separator plate (100) and the second separator plate (200).

[0089] At this time, the separation portion (211) and extension portion (212) of the insertion portion (210) formed on the same short axis in the second separator plate (200) are formed in opposite directions. Thus, the assembly points where the fastening portion (110) and the insertion portion (210) are fastened, namely assembly points C3 and C4 shown in FIG. 14, are assembled in opposite directions.

[0090] As shown in FIG. 14, in order to assemble in opposite directions at assembly points C3 and C4, first, an insertion part (210) is inserted into the fastening part (110) at assembly point (C3), and then, utilizing the elasticity of the second separating plate (200), the second separating plate (200) is bent in the short-axis direction, and then an insertion part (210) is inserted into the fastening part (110) at assembly point (C4).

[0092] Meanwhile, for a robust assembly of the first separator plate (100) and the second separator plate (200), the fastening portion (110) of the first separator plate (100) is formed at least two points on each side edge area based on the short axis direction of the first separator plate (100), and the insertion portion (210) of the second separator plate (200) is preferably formed corresponding to the points where the fastening portion (110) is formed.

[0093] Therefore, it is preferable that the fastening part (110) formed on the first separator plate (100) and the insertion part (210) formed on the second separator plate (200) each be formed with at least 4 or more.

[0095] Although the present invention has been described with reference to the accompanying drawings and the aforementioned preferred embodiments, the present invention is not limited thereto but is defined by the claims set forth below. Accordingly, those skilled in the art can make various modifications and variations to the present invention within the scope of the technical spirit of the claims set forth below without departing from the technical spirit of the present invention. Explanation of the symbols

[0097] 10: Membrane Electrode Assembly (MEA) 20: Gas Diffusion Layer (GDL) 30: Separator 40: Gasket 50: End plate 100: First separator 110: Connecting part 111, 112, 113, 114: Inlet 200: Second separator plate 210: Insert part 211, 213: Separation part 212, 214: Extension part

Claims

Claim 1 A fuel cell separator assembly comprising a pair of separator plates, wherein the first separator plate has a tunnel-shaped fastening portion formed at a plurality of points in a perimeter region; and the second separator plate has an insertion portion formed at a position in the perimeter region corresponding to the fastening portion of the first separator plate, into which the insertion portion of the second separator plate is inserted, so as to assemble the first separator plate and the second separator plate, wherein the fastening portion of the first separator plate is bent and protrudes in a direction facing the second separator plate, and at least one end of the two ends is opened to form an inlet. Claim 2 delete Claim 3 A fuel cell separator assembly according to claim 1, characterized in that the insertion portion of the second separator is bent and extended to be inserted into the inlet while protruding in a direction facing the first separator. Claim 4 A fuel cell separator assembly according to claim 1, wherein the fastening portion of the first separator is formed along the long axis direction of the first separator, and a pair of inlets are formed at both ends based on the long axis direction, and the pair of inlets are connected to each other. Claim 5 A fuel cell separator assembly according to claim 4, wherein the insertion portion of the second separator is formed along the long axis direction of the second separator, and with respect to the long axis direction, an extension portion is formed that is bent while extending integrally with the main body of the second separator at one end, and a separation portion is formed that is spaced apart from the main body of the second separator at the other end, so that the insertion portion is inserted into the inlet of the fastening portion through the separation portion. Claim 6 A fuel cell separator assembly according to claim 1, wherein the fastening portion of the first separator is formed along the short axis direction of the first separator, and a pair of inlets are formed at both ends based on the short axis direction, and the pair of inlets are connected to each other. Claim 7 A fuel cell separator assembly according to claim 6, wherein the insertion portion of the second separator is formed along the short axis direction of the second separator, and with respect to the short axis direction, an extension portion is formed that is bent while extending integrally with the main body of the second separator, and a separation portion is formed at the other end that is spaced apart from the main body of the second separator, so that the insertion portion is inserted into the inlet of the fastening portion through the separation portion. Claim 8 A fuel cell separator assembly according to claim 1, wherein the fastening portion of the first separator is formed at least two points each in the edge areas on both sides based on the short axis direction of the first separator, and the insertion portion of the second separator is formed corresponding to the point where the fastening portion is formed. Claim 9 A fuel cell separator assembly according to claim 8, characterized in that the direction of the insertion part inserted into the fastening part along the same major axis is the same direction. Claim 10 A fuel cell separator assembly according to claim 8, characterized in that the directions of the insertion portions inserted into the fastening portions along the same major axis are opposite to each other. Claim 11 A fuel cell separator assembly according to claim 8, characterized in that the direction of the insertion part inserted into the fastening part on the same short axis is the same direction. Claim 12 A fuel cell separator assembly according to claim 8, characterized in that the directions of the insertion portions inserted into the fastening portions along the same short axis are opposite to each other. Claim 13 A fuel cell stack formed by stacking a plurality of fuel cell cells, each comprising a membrane electrode assembly, a pair of gas diffusion layers, a first separator, and a second separator, wherein a tunnel-shaped fastening portion is formed at a plurality of points in the edge region of the first separator, and an insertion portion is formed in the edge region of the second separator at a position corresponding to the fastening portion of the first separator, into which the fastening portion is inserted, and the insertion portion of the second separator is inserted into the fastening portion of the first separator so that the first separator and the second separator are assembled, and the fastening portion of the first separator is bent and protruded in a direction facing the second separator, and at least one end is opened to form an inlet.

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