Unit cell of fuel cell stack

Abstract

An embodiment of a unit cell of a fuel cell stack includes: a power generation assembly (EGA) in which a membrane electrode assembly and a gas diffusion layer are bonded; a sheet including a slot into which the power generating component can be inserted and a through hole through which the gas flows; a first separator coupled to the sheet and including a first reaction flow field through which a first gas flows on a first side of the first separator; and a second diaphragm coupled to the sheet and including a second reaction flow field through which a second gas flows on a first side of the second diaphragm, the second gas flow field connected to a first end or a second end of the second reaction flow field, and the first gas flow field is connected to the first reaction flow field through a through hole arranged at a point position spaced from the second gas flow field.

Description

Technical Field

[0001] The present disclosure relates to unit cells of a fuel cell stack. Background Art

[0002] A fuel cell is a device that receives hydrogen and air from the outside and generates electric energy through an electrochemical reaction within a fuel cell stack, and can be used as a power source in various fields such as a fuel cell vehicle (FCEV) and a fuel cell for power generation.

[0003] The fuel cell system includes a fuel cell stack that stacks multiple unit cells and serves as a power source, a fuel supply system that supplies hydrogen (which is a fuel) to the fuel cell stack, an air supply system that supplies oxygen (which is an oxidant required for the electrochemical reaction), a water and thermal management system that controls the temperature of the fuel cell stack, etc.

[0004] When hydrogen is supplied to the anode of the fuel cell stack and air is supplied to the cathode, an electrochemical reaction occurs between the hydrogen and oxygen in the air, generating electric energy and water (product water).

[0005] at the same time, Figure 1 is a schematic diagram showing the construction of a typical fuel cell stack.

[0006] If available Figure 1 As can be seen in the figure, in the unit cells forming a typical fuel cell stack, the membrane electrode assembly (MEA) 10 is located at the innermost side, and the membrane electrode assembly 10 is composed of a polymer electrolyte membrane 11 capable of moving hydrogen cations (protons) and catalyst layers (i.e., a fuel electrode (anode) 12 and an air electrode (cathode) 13) coated on both sides of the polymer electrolyte membrane.

[0007] In addition, a pair of gas diffusion layers (GDL) 20 are stacked on the outside of the membrane electrode assembly 10, that is, on the outside where the fuel electrode 12 and the air electrode 13 are located, and a separator assembly 30 (having a flow field formed therein to supply fuel and discharge water generated by the reaction) is located on the outside of the gas diffusion layer 20, with a gasket 40 interposed therebetween.

[0008] Here, the separator assembly 30 is formed by combining an anode separator 31 disposed on the anode and a cathode separator 32 disposed on the cathode to face each other.

[0009] Meanwhile, the fuel cell stack is formed by stacking a plurality of unit cells, and the end plate 50 for supporting and fixing each of the above components is coupled to the outermost sides of the stacked unit cells.

[0010] Here, the anode separator 31 provided in any one unit cell is stacked to face the cathode separator 32 of another unit cell provided adjacent to the above-mentioned unit cell.

[0011] Accordingly, the separator assembly 30 in which the cathode separator 32 and the anode separator 31 of adjacent unit cells disposed to face each other are formed as one body is used to construct the unit cells to smoothly perform the stacking process of the unit cells and maintain the alignment of the respective unit cells.

[0012] Here, the anode separator 31 and the cathode separator 32 for forming the separator assembly 30 are combined and formed as one body so that manifolds communicate with each other and each reaction region is configured in a similar shape to be disposed at the same position.

[0013] Meanwhile, a gasket 40 is formed on the surface of the anode separator 31 and the cathode separator 32 using an injection molding method, and the gasket forms an airtight line and a flow path for a reaction gas or cooling water.

[0014] The matters described above as background art are only for enhancing the understanding of the background of the embodiments of the present disclosure and should not be regarded as an admission that they correspond to the prior art known to those skilled in the art. Summary of the invention

[0015] The present disclosure relates to a unit cell of a fuel cell stack. Detailed Description of the Invention The present disclosure relates to a unit cell of a fuel cell stack, wherein a sheet into which an electricity generating assembly (EGA) can be inserted is applied to the unit cell.

[0016] Embodiments of the present disclosure provide a unit cell of a fuel cell stack in which deformation of a first separator and a second separator can be suppressed by gaskets provided on both sides of the second separator even when a large number of fuel cells are stacked.

[0017] In addition, an embodiment of the present disclosure provides a unit cell of a fuel cell stack, which can maintain uniform surface pressure at all points of the cell even when a plurality of fuel cells are stacked, and can maintain airtightness when the fuel cells are stacked by forming a flow path for the reaction gas by a gasket arranged on a second separator to face the sheet and the sheet.

[0018] The unit cell of the fuel cell stack according to an embodiment of the present disclosure includes: a power generation assembly (EGA) in which a membrane electrode assembly and a gas diffusion layer are combined; a sheet including a slot for inserting the EGA and through holes through which gas flows at multiple points; a first separator connected to the sheet and including a first reaction flow field through which a first gas flows on one side of the first separator; and a second separator connected to the sheet, and a second reaction flow field through which a second gas flows is formed on one side of the second separator, the second gas flow field is connected to one or more of one end and the other end of the second reaction flow field, and the first gas flow field is connected to the first reaction flow field through through holes formed in the sheet at points spaced apart from the second gas flow field.

[0019] The gas diffusion layer of the EGA may include a first gas diffusion layer and a second gas diffusion layer, the area of ​​the first gas diffusion layer may be smaller than that of the second gas diffusion layer, and the first gas diffusion layer may be inserted into the slot of the sheet so that one side of the sheet may contact the membrane electrode assembly.

[0020] The first gas manifold for inflow and outflow of the first gas and the second gas manifold for inflow and outflow of the second gas may be formed at a plurality of points on one or more of the first separator, the second separator, and the sheet.

[0021] The first gas flow field may be connected to a first gas manifold formed in the second separator, and the second gas flow field may be connected to a second gas manifold formed in the second separator.

[0022] The first gas may flow into the first gas flow field through the first gas manifold, and the first gas flowing into the first gas flow field may pass through the through holes of the sheet and flow into the first reaction flow field of the first separator.

[0023] One end of the first gas flow field may be bent and connected to the through hole.

[0024] The gasket may be disposed around one or more of the first gas manifold, the second gas manifold, the second reaction flow field, the first gas flow field, and the second gas flow field formed on one side of the second separator.

[0025] The gasket disposed around one or more of the first gas manifold, the second gas manifold, and the second reaction flow field may be disposed continuously, and the gasket disposed around one or more of the first gas flow field and the second gas flow field may be disposed discontinuously.

[0026] The gasket may be disposed between adjacent first gas flow fields or adjacent second gas flow fields.

[0027] The gasket disposed around one or more of the first gas manifold and the second gas manifold may be disposed discontinuously.

[0028] A coolant manifold for coolant to flow in and out is formed on one or more of the first separator, the second separator, and the sheet on which the first gas manifold and the second gas manifold are formed, and a coolant flow field for coolant to flow through may be formed on the other side of the first separator or the second separator.

[0029] The gasket may be disposed around one or more of the first gas manifold, the second gas manifold, the coolant manifold, and the coolant flow field formed on the other side of the second separator.

[0030] A gasket disposed around one or more of the first gas manifold and the second gas manifold may be disposed to surround one or more of the first gas manifold and the second gas manifold.

[0031] Gaskets may be provided on one side and the other side of the second separator, and adhesive may be applied around the gaskets to attach the second separator to the sheet.

[0032] According to the unit cells of the fuel cell stack of the embodiment of the present disclosure, even when a large number of fuel cells are stacked, the gaskets provided on both sides of the second separator can prevent the first separator and the second separator from deforming, and even if multiple fuel cells are stacked, uniform surface pressure can be maintained at all points of the cell.

[0033] Furthermore, when a sheet provided separately from the separator is punched into a desired shape and placed between a pair of separators, a gasket provided on the separator to face the sheet and the sheet form a flow path for the reaction gas, so that double sealing can be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram showing the construction of a typical fuel cell stack.

[0035] Figure 2 is a schematic diagram showing an exploded view of a unit cell of a fuel cell stack according to an embodiment of the present disclosure.

[0036] Figure 3 FIG. 1 is a schematic diagram showing one side of the second separator of a unit cell when the cells are stacked, wherein an AA′ cross section and a BB′ cross section are shown.

[0037] Figure 4 FIG. 1 is a schematic diagram showing one side of the second separator of a unit cell when the cells are stacked, wherein a CC' cross section and a DD' cross section are shown.

[0038] Figure 5 FIG. 1 is a schematic diagram showing a gasket provided on a second separator according to a second embodiment.

[0039] Figure 6 Schematic diagram showing the cooling surface of the second separator according to the second embodiment.

[0040] Figure 7 It is a schematic diagram showing the EE' section when the other side of the second separator and the battery are stacked.

[0041] Figure 8 Schematic diagram showing an EGA coupled to a sheet and the sheet. DETAILED DESCRIPTION

[0042] Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar elements are denoted by the same reference numerals in all the drawings, and redundant descriptions are omitted.

[0043] When describing the embodiments disclosed in this specification, detailed descriptions of related known technologies may not be given to avoid blurring the subject matter of the embodiments disclosed in this specification. In addition, the drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, rather than to limit the technical spirit disclosed in this specification. In addition, the drawings should be understood to cover all changes, equivalents or alternatives within the spirit and technical scope of the present disclosure.

[0044] Although terms including ordinal numbers such as first, second, etc. may be used to describe various elements, the constituent elements are not limited by the terms. Such terms are used only to distinguish one element from another.

[0045] Unless the context clearly indicates otherwise, a singular expression includes a plural expression.

[0046] In the present disclosure, terms such as “include” or “have” may be understood to indicate certain features, quantities, steps, operations, constituent elements, parts or a combination thereof, but may not be understood to exclude the possibility of the existence or addition of one or more other features, quantities, steps, operations, constituent elements, parts or a combination thereof.

[0047] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intervening elements. In contrast, it should be understood that when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0048] Figure 2 Schematic diagram showing an exploded view of a unit cell of a fuel cell stack according to an embodiment of the present disclosure. Figure 2 , a unit cell of a fuel cell stack includes: a power generation assembly (EGA), in which a membrane electrode assembly (MEA) and a gas diffusion layer (GDL) are combined; a sheet 200; a first separator 400 and a second separator 300, in which the EGA 100 is connected to the sheet 200, and the second separator 300 and the first separator 400 are respectively connected to both sides of the sheet 200.

[0049] When stacking Figure 2 When the unit cells of the fuel cell stack shown are connected, a fuel cell stack is formed.

[0050] Meanwhile, in the present specification, the first separator 400 may be a cathode separator or an anode separator, and the same applies to the second separator 300. In addition, the first gas may be air or hydrogen, and the same applies to the second gas. However, for the convenience of explaining the embodiments of the present disclosure, it is assumed that in the embodiments of the present disclosure, the first separator is used as an anode separator, the second separator is used as a cathode separator, and the first gas is hydrogen and the second gas is air.

[0051] Specifically, in describing each configuration, the sheet 200 is configured to accommodate the EGA 100. The EGA 100 is a material having ductility and low strength, and the sheet 200 helps the EGA 100 maintain its shape, protects the EGA 100 from external forces, and serves to assist in fixing the EGA 100 within the unit cell.

[0052] The sheet 200 is made of a material that can be easily compressed and stamped, such as plastic or rubber, and is preferably made of a material that maintains the shape of the EGA 100 and has a hardness that can protect the EGA 100. In addition, the sheet 200 can be used as a separate piece to accommodate the EGA 100.

[0053] Meanwhile, a slot 210 into which the EGA 100 is inserted is formed at the center of the sheet 200. The slot 210 is formed by punching, and the slot 210 is punched into a shape that can accommodate the EGA 100, so that the EGA 100 can be inserted and accommodated in the sheet 200.

[0054] The first separator 400 and the second separator 300 are coupled to each side of the sheet 200 to which the EGA 100 is attached. The first separator 400 and the second separator 300 coupled to the sheet 200 are both coupled to the sheet 200 by an adhesive 800 .

[0055] The first separator 400 is coupled to the sheet 200 such that one side of the first separator 400 faces the sheet 200. A first reaction flow field 430 for the first gas to flow therethrough is formed on one side of the first separator 400. The first gas may diffuse into the EGA 100 through the first reaction flow field 430 and react with the second gas to generate electricity.

[0056] The second separator 300 is also coupled to the sheet 200 such that one side of the second separator 300 faces the sheet 200. A second reaction flow field 350 for the second gas to flow through is formed on one side of the second separator 300. The second gas may diffuse into the EGA 100 through the second reaction flow field 350 and react with the first gas to generate electricity.

[0057] The second gas flow field 310 is formed on one side of the second separator 300 to deliver the second gas to the second reaction flow field 350. The second gas flow field 310 is connected to the second reaction flow field 350 so that the second gas can be delivered to the second reaction flow field 350. A portion of the second gas may flow into the second reaction flow field 350 and react with the first gas, and a portion of the second gas may pass through the second reaction flow field 350 and flow back into the second gas flow field 310.

[0058] The first gas flow field 330 is formed on one side of the second separator 300 to deliver the first gas to the first reaction flow field 430. The first gas flow field 330 is formed on one side of the second separator 300 but is connected to the first reaction flow field 430 of the first separator 400. Specifically, refer to Figure 2 , the second gas flow field 310 is connected to the second reaction flow field 350 , while the first gas flow field 330 is not connected to the second reaction flow field 350 , and one end of the first gas flow field 330 is formed in a bent shape to face the first reaction flow field 430 .

[0059] That is, the first gas flowing in the first gas flow field 330 flows from one end of the first gas flow field 330 into the first reaction flow field 430 of the first separator 400 .

[0060] In this case, the through holes 230 are formed in the sheet 200, and the through holes 230 are formed at points corresponding to the bending points of the first gas flow fields 330. Therefore, the first gas moving through the first gas flow fields 330 passes through the through holes 230 and flows into the first reaction flow field 430. The number of the through holes 230 may be formed as many as the number of the first gas flow fields 330.

[0061] In addition, a portion of the first gas may flow into the first reaction flow field 430 and react with the second gas, while a portion of the first gas may pass through the first reaction flow field 430 and through the through holes 230 again, thereby flowing into the first gas flow field 330 of the second separator 300 .

[0062] Figure 3 Schematic diagram showing one side of the second separator of a unit cell when the cells are stacked, wherein an AA' cross section and a BB' cross section are shown. Figure 3 , the flow of the first gas will be described in detail.

[0063] First, referring to the AA' section, the first gas flows into the first gas flow field 330. The first gas flowing into the first gas flow field 330 passes through the through hole 230 along the first gas flow field 330 bent at one end thereof and moves to the first reaction flow field 430 of the first separator 400 connected to the first gas flow field 330.

[0064] A portion of the first gas flowing into the first reaction flow field 430 reacts with the second gas, while a portion of the first gas passes through the first reaction flow field 430, passes through the through hole 230 again, and flows into the first gas flow field 330 of the second separator 300. That is, referring to the BB' section, the first gas that has passed through the first reaction flow field 430 passes through the through hole 230 and flows back into the first gas flow field 330 of the second separator 300.

[0065] Figure 4FIG. 1 is a schematic diagram showing one side of the second separator of a unit cell when the cells are stacked, wherein a CC' cross section and a DD' cross section are shown. Figure 4 , the flow of the second gas will be described in detail.

[0066] First, referring to the CC' section, the second gas flows into the second gas flow field 310. The second gas flowing into the second gas flow field 310 flows into the second reaction flow field 350 connected to the second gas flow field 310. A portion of the second gas flowing into the second reaction flow field 350 reacts with the first gas, while a portion of the second gas passes through the second reaction flow field 350 and flows into the second gas flow field 310. That is, referring to the D-D' section, it can be seen that the second gas that has passed through the second reaction flow field 350 passes through the second reaction flow field 350 and flows into the second gas flow field 310.

[0067] Specifically, the flows of the first gas and the second gas will be described.

[0068] A plurality of points at one or more of the first separator 400, the second separator 300, and the sheet 200 have first gas manifolds 380, 390, 280, 290, 480, 490 for the first gas to flow in and out and second gas manifolds 360, 370, 260, 270, 460, 470 for the second gas to flow in and out. The first gas manifolds 380, 390, 280, 290, 480, 490 may be formed as a pair. One first gas manifold 380, 280, 480 may correspond to a portion where the first gas flows in, and the other first gas manifold 390, 290, 490 may correspond to a portion where the first gas flows out.

[0069] Likewise, the second gas manifolds 360, 370, 260, 270, 460, 470 may be formed as a pair. One second gas manifold 360, 260, 460 may correspond to a portion where the second gas flows in, and the other second gas manifold 370, 270, 470 may correspond to a portion where the second gas flows out.

[0070] Specifically, the first gas manifolds 380 and 390 formed on the second separator 300 may be connected to the other end of the first gas flow field 330 , and the second gas manifolds 360 and 370 formed on the second separator 300 may be connected to the other end of the second gas flow field 310 .

[0071] The first gas manifolds 380, 390, 280, 290, 480, 490 and the second gas manifolds 360, 370, 260, 270, 460, 470 are preferably formed at points corresponding to each other in the first separator 400, the second separator 300 and the sheet 200. Meanwhile, the first gas manifolds 380, 390, 280, 290, 480, 490 and the second gas manifolds 360, 370, 260, 270, 460, 470 may be formed to face each other, and the paired first gas manifolds 380, 390, 280, 290, 480, 490 may face each other diagonally, and the second gas manifolds 360, 370, 260, 270, 460, 470 may also face each other diagonally.

[0072] Meanwhile, the gasket may be disposed in the unit cell of the fuel cell stack to prevent the gas outside the unit cell from flowing into the unit cell or the gas inside the unit cell from flowing out. Specifically, the gasket 530 may be disposed around one or more of the first gas manifolds 380, 390, the second gas manifolds 360, 370, the second reaction flow field 350, the first gas flow field 330, and the second gas flow field 310 formed on one side of the second separator 300.

[0073] refer to Figure 3 and Figure 4 The first gas manifolds 380, 390 are arranged on one side of the second partition plate 300, and the gasket 530 is arranged around the second gas manifolds 360, 370, so that the first gas and the second gas can be prevented from flowing to the outside, and the gasket 530 is also arranged around the second reaction flow field 350 to prevent the second gas from flowing to the outside.

[0074] In addition, both the first separator 400 and the second separator 300 may be coupled to the sheet 200 by an adhesive. Specifically, an adhesive 800 may be applied around the gasket of the second separator 300 to couple the second separator 300 to the sheet 200.

[0075] Adhesive 800 may also be applied to the exterior of the first separator 400 to couple the first separator 400 to the sheet 200 .

[0076] That is, there is an adhesive layer formed by the adhesive 800 between the sheet 200 and the first separator 400 and between the sheet 200 and the second separator 300, and there is an advantage that the airtightness between the sheet 200 and the first separator 400 and between the sheet 200 and the second separator 300 can be ensured by the adhesive layer.

[0077] Since the first gas flow field 330 and the second gas flow field 310 are respectively channels for the first gas and the second gas to flow, the gasket 530 disposed around one or more of the first gas flow field 330 and the second gas flow field 310 may be disposed discontinuously. However, the gasket 530 disposed around one or more of the first gas manifolds 380, 390, the second gas manifolds 360, 370, and the second reaction flow field 350 may be disposed continuously, so that the first gas manifolds 380, 390, the second gas manifolds 360, 370, and the second reaction flow field 350 are used to maintain the airtightness of the unit cells of the fuel cell stack.

[0078] More specifically, the gasket 530 disposed around the first gas flow field 330 or the second gas flow field 310 may be disposed between adjacent first gas flow fields 330 or adjacent second gas flow fields 310 .

[0079] The gasket 530 may be injected into the second separator 300 to be disposed on the second separator 300. By integrally disposing the gasket 530 on the second separator 300, when the unit batteries are stacked, the surface pressure is kept uniform, and the first separator 400 and the second separator 300 may be suppressed from being deformed.

[0080] Meanwhile, when the first gas reacts with the second gas, water is generated inside the unit cell. The generated water may be discharged to the outside by air pressure caused by operating the air compressor, but due to the gasket 530 provided around the first gas manifold 380, 390 or the second gas manifold 360, 370, the water generated around the first gas manifold 380, 390 or the second gas manifold 360, 370 may not escape and may accumulate inside the unit cell.

[0081] Water accumulated inside the unit cell has a negative impact on the durability of the fuel cell stack. For example, when the external temperature drops below the freezing point, the phase of water changes to solid and the volume increases. The increased volume may cause damage to the internal parts of the unit cell, and the degradation of the membrane electrode assembly may be accelerated due to the increase in relative humidity inside the unit cell. Therefore, it is necessary to remove the water generated around the first gas manifold 380, 390 or the second gas manifold 360, 370.

[0082] The unit cells of the fuel cell stack according to the second embodiment of the present disclosure have gaskets 570 disposed discontinuously around one or more of the first gas manifolds 380, 390 and the second gas manifolds 360, 370. Even if water is generated around the first gas manifolds 380, 390 or the second gas manifolds 360, 370, the water can escape between the gaskets 570 disposed discontinuously.

[0083] Figure 5FIG. 2 is a schematic diagram showing a gasket disposed on the second separator according to the second embodiment. Figure 5 The gasket 570 is disposed around the first gas manifold 380, 390 and the second gas manifold 360, 370, but is not Figure 3 Differently, it can be seen that the gasket 570 is disposed discontinuously.

[0084] Thus, even if water is generated around the first gas manifolds 380 , 390 or the second gas manifolds 360 , 370 , the water can escape through the discontinuous gasket 570 , so that the durability of the fuel cell stack can be prevented from being reduced due to freezing of the accumulated water.

[0085] Figure 6 Schematic diagram showing the cooling surface of the second separator according to the second embodiment.

[0086] When based on Figure 5 When constructing the reaction surface in the second embodiment shown in FIG. Figure 6 The cooling surface is constructed as shown.

[0087] like Figure 6 As shown, the gasket 630 disposed on the other side of the second separator 300 is disposed around one or more of the first gas manifolds 380 , 390 and the second gas manifolds 360 , 370 , and specifically, the gasket 630 may be disposed to completely surround one or more of the first gas manifolds 380 , 390 and the second gas manifolds 360 , 370 .

[0088] Meanwhile, as described above, one side of each of the first separator 400 and the second separator 300 constitutes a reaction surface where the first gas and the second gas flow to cause an electrochemical reaction.

[0089] On the other hand, the other side of each of the first separator 400 and the second separator 300 forms a cooling surface for cooling the reaction heat generated by the electrochemical reaction of the first gas and the second gas. Therefore, when the unit batteries are stacked, the other side of the first separator 400 and the other side of the second separator 300 can be stacked to face each other.

[0090] Figure 7 It is a schematic diagram showing the EE' section when the other side of the second separator and the battery are stacked.

[0091] refer to Figure 2 and Figure 6, coolant manifolds 322, 321, 222, 221, 422, and 421 for coolant inflow and outflow may be formed on one of the first separator 400, the second separator 300, and the sheet 200 on which the first gas manifolds 380, 390, 280, 290, 480, 490 and the second gas manifolds 360, 370, 260, 270, 460, 470 are formed. The coolant may flow into the other side of the first separator 400 and the second separator 300 and into the coolant flow field 325 to cool the unit cells of the fuel cell stack, and then may flow out again through the coolant manifolds 322, 321, 222, 221, 422, 421.

[0092] Meanwhile, the gasket 630 may be disposed around one or more of the first gas manifolds 380 , 390 , the second gas manifolds 360 , 370 , the coolant manifolds 322 , 321 , and the coolant flow field 325 formed on the other side of the second separator 300 .

[0093] Specifically, just as the gasket 530 is disposed on one side of the second separator 300 to maintain airtightness, the gasket 630 may be disposed on the other side of the second separator 300 to maintain watertightness.

[0094] The gasket 630 disposed on the other side of the second separator 300 is disposed around one or more of the first gas manifolds 380 , 390 and the second gas manifolds 360 , 370 , and specifically, the gasket 630 may be disposed to completely surround one or more of the first gas manifolds 380 , 390 and the second gas manifolds 360 , 370 .

[0095] That is, the gasket 630 may be injected to completely surround the first gas manifold 380 , 390 and the second gas manifold 360 , 370 to prevent the first gas or the second gas from flowing into the other side of the second separator 300 corresponding to the cooling surface, and the gasket 630 may be injected around the coolant flow field 325 to prevent the coolant from flowing out.

[0096] Meanwhile, the gasket 730 may be disposed around the coolant manifolds 322 , 321 formed on the other side of the second separator 300 , and the gasket 730 disposed around the coolant manifolds 322 , 321 may serve to guide the flow of the coolant.

[0097] By providing the gasket 630 , 730 on the other side of the second separator 300 , when the unit batteries are stacked, the surface pressure is kept uniform, and deformation of the first separator 400 and the second separator 300 may be suppressed.

[0098] at the same time, Figure 8 Schematic diagram showing an EGA coupled to a sheet and the sheet.

[0099] refer to Figure 8 , gas diffusion layers 121, 122 are bonded to each side of the membrane electrode assembly 110 to form the EGA 100. The gas diffusion layers 121, 122 include a first gas diffusion layer 121 bonded to one side of the membrane electrode assembly 110 and a second gas diffusion layer 122 bonded to the other side of the membrane electrode assembly 110. In order to stably dispose the EGA 100 on the sheet 200, the areas of the first gas diffusion layer 121 and the second gas diffusion layer 122 may be configured differently.

[0100] like Figure 8 As shown, the area of ​​the first gas diffusion layer 121 is formed to be smaller than the area of ​​the second gas diffusion layer 122, so that when the EGA 100 is inserted into the slot of the sheet 200, as the first gas diffusion layer 121 is inserted into the slot 210, the rest of the sheet 200 can contact the membrane electrode assembly 110.

[0101] While embodiments of the present disclosure have been shown and described with respect to the particular exemplary embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure as defined in the following claims.

Claims

1. A unit cell of a fuel cell stack, the unit cell comprising: an electricity generating assembly (EGA) in which a membrane electrode assembly and a gas diffusion layer are combined; a sheet comprising a slot and a through hole configured to allow gas to flow therethrough, wherein the power generation assembly is insertable into the slot; a first separator plate coupled to the sheet and comprising a first reaction flow field for a first gas to flow through on a first side of the first separator plate; and A second separator is connected to the sheet and includes a second reaction flow field for a second gas to flow through on a first side of the second separator, the second gas flow field is connected to the first end or the second end of the second reaction flow field, and the first gas flow field is connected to the first reaction flow field through the through hole provided in the sheet at a point spaced apart from the second gas flow field.

2. The unit cell according to claim 1, wherein: The gas diffusion layer of the power generation component includes a first gas diffusion layer and a second gas diffusion layer, the area of ​​the first gas diffusion layer is smaller than that of the second gas diffusion layer, and the first gas diffusion layer can be inserted into the slot of the sheet so that one side of the sheet contacts the membrane electrode assembly.

3. The unit cell according to claim 1, further comprising a first gas manifold configured to allow the first gas to flow therethrough and a second gas manifold configured to allow the second gas to flow therethrough, wherein: The first gas manifold and the second gas manifold are disposed at a plurality of points of the first separator, the second separator, or the sheet.

4. The unit cell according to claim 3, wherein: The first gas flow field is connected to the first gas manifold disposed in the second separator, and wherein the second gas flow field is connected to the second gas manifold disposed in the second separator.

5. The unit cell according to claim 3, wherein: The first gas can flow into the first gas flow field through the first gas manifold, and the first gas flowing into the first gas flow field passes through the through holes of the sheet and flows into the first reaction flow field of the first separator.

6. The unit cell according to claim 3, wherein: One end of the first gas flow field is bent and connected to the through hole. 7 . The unit cell according to claim 3 , further comprising a gasket disposed around the first gas manifold, the second gas manifold, the second reaction flow field, the first gas flow field, or the second gas flow field disposed on one side of the second separator.

8. The unit cell according to claim 7, wherein: The gasket comprises: A first gasket disposed around the first gas manifold, the second gas manifold, or the second reaction flow field; and A second gasket is disposed around the first gas flow field and the second gas flow field.

9. The unit cell according to claim 8, wherein: The first gasket is continuous and the second gasket is discontinuous.

10. The unit cell according to claim 7, wherein: The gasket is disposed between adjacent first gas flow fields or adjacent second gas flow fields.

11. The unit cell according to claim 7, wherein: The gasket is disposed around the first gas manifold or the second gas manifold, and wherein the gasket is discontinuous.

12. The unit cell according to claim 3, further comprising: a coolant manifold through which a coolant can flow, the coolant manifold being disposed on the first separator, the second separator, or the sheet on which the first gas manifold and the second gas manifold are disposed; and A coolant flow field through which the coolant can flow is provided on the second side of the first separator or the second separator. 13 . The unit cell according to claim 12 , further comprising a gasket disposed around the first gas manifold, the second gas manifold, the coolant manifold, or the coolant flow field disposed on the second side of the second separator.

14. The unit cell according to claim 13, wherein: The gasket surrounds the first gas manifold or the second gas manifold.

15. The unit cell according to claim 1, further comprising: a first gasket disposed on the first side of the second separator and a second gasket disposed on the second side of the second separator; and An adhesive is positioned around the first gasket to attach the second separator to the sheet.

16. A unit cell of a fuel cell stack, the unit cell comprising: an electricity generating assembly (EGA) in which a membrane electrode assembly and a gas diffusion layer are combined; a sheet including slots and through holes configured for gas flow therethrough, wherein the power generation assembly is insertable into the slots; a first separator plate coupled to the sheet and comprising a first reaction flow field for a first gas to flow through on a first side of the first separator plate; and A second separator is connected to the sheet and includes a second reaction flow field for a second gas to flow through on a first side of the second separator, the second gas flow field is connected to the first end or the second end of the second reaction flow field, and the first gas flow field is connected to the first reaction flow field through the through hole provided in the sheet at a point spaced apart from the second gas flow field, wherein an end of the first gas flow field is bent and connected to the through hole.

17. The unit cell according to claim 16, wherein: The gas diffusion layer of the power generation component includes a first gas diffusion layer and a second gas diffusion layer, the area of ​​the first gas diffusion layer is smaller than that of the second gas diffusion layer, and the first gas diffusion layer can be inserted into the slot of the sheet so that one side of the sheet contacts the membrane electrode assembly.

18. The unit cell according to claim 16, further comprising a first gas manifold configured to allow the first gas to flow therethrough and a second gas manifold configured to allow the second gas to flow therethrough, wherein: The first gas manifold and the second gas manifold are disposed at a plurality of points of the first separator, the second separator, or the sheet. 19 . The unit cell according to claim 18 , further comprising a gasket disposed around the first gas manifold, the second gas manifold, the second reaction flow field, the first gas flow field, or the second gas flow field disposed on one side of the second separator.

20. The unit cell according to claim 16, further comprising: a first gasket disposed on the first side of the second separator and a second gasket disposed on the second side of the second separator; and An adhesive is positioned around the first gasket to attach the second separator to the sheet.

Images