Multi-perforated plate for separator of fuel cell and fuel cell

Abstract

A multi-perforated plate for a separator of a fuel cell and a fuel cell are provided. The multi-perforated plate is disposed between a separator in a flat plate shape and a gas diffusion layer to form a flow path for a reaction gas, and the multi-perforated plate includes: a porous region having an uneven shape repeatedly formed in the porous region and provided with a plurality of flow path holes configured to allow the reaction gas to flow in a turbulent manner; and a channel region forming a flow path configured to allow the reaction gas to flow linearly along the flow direction of the reaction gas, wherein the porous region and the channel region are alternately arranged and integrally formed.

Description

Technical Field

[0001] The present invention relates to a perforation plate for a separator of a fuel cell. Background Art

[0002] A fuel cell is a power generation device that converts chemical energy contained in fuel into electrical energy through an electrochemical reaction in a stack body. The fuel cell is used not only to supply driving power in industries, homes, and vehicles but also to supply power to small electronic products such as portable devices. Therefore, the fuel cell can be used as an efficient clean energy source, and its application range is gradually expanding.

[0003] A unit cell constituting a fuel cell includes an electrolyte membrane, electrodes (i.e., an anode and a cathode), a gas diffusion layer (GDL), and a separator. In addition, these unit cells are stacked to form a fuel cell stack.

[0004] On the other hand, in recent years, since the gas diffusion layer and the separator are in direct contact with each other, in order to improve the diffusion ability of reaction gases, a perforation plate having a microporous structure is inserted between the gas diffusion layer and the separator while preventing the gas diffusion layer from being locally damaged due to the uneven pattern of the separator.

[0005] The perforation plate is used in such a way that the surface pressure applied to the gas diffusion layer is made uniform, and the turbulence of the reaction gases is guided, thereby protecting the gas diffusion layer, and the flows of the reaction gases and cooling water are uniformly distributed over the entire reaction area.

[0006] Figure 1 is a schematic view showing the configuration of a general unit cell of a fuel cell to which a conventional perforation plate is applied.

[0007] As Figure 1 shown, a conventional unit cell of a fuel cell to which a perforation plate is applied includes: a membrane electrode assembly (MEA) 10 including an electrolyte membrane 11 and a pair of electrodes 12a and 12b; a gas diffusion layer (GDL) 20 disposed on opposite sides of the membrane electrode assembly 10; a separator 31 disposed outside the gas diffusion layer 20; and a perforation plate 32 interposed between the gas diffusion layer 20 and the separator 31. Generally, the separator 31 and the perforation plate 32 are used together to form a porous separator 30, and in the unit cell of a conventional fuel cell, such a porous separator 30 serves as a separator in which a flow path having a linear shape is formed.

[0008] At this time, the separator 31 may be configured in various forms, but is preferably made of a flat plate having a planar shape.

[0009] Meanwhile, the multi-perforated plate 32 is formed by processing a plate-shaped material having a plurality of flow path holes, and is formed by repeatedly forming a corrugated cross section along the flow direction of the reaction gas, and thus is configured to have an uneven shape.

[0010] Therefore, when the reaction gas flows through the multi-perforated plate 32, the reaction gas flows in a turbulent manner when passing through the plurality of flow path holes in a zigzag manner, and as a whole flows in a direction from one side of the multi-perforated plate 32 toward the other side thereof.

[0011] Meanwhile, since fuel cells are applied to various platforms, it is necessary to improve the power density of fuel cells.

[0012] Since the interval between cells must be reduced to increase the power density, it is necessary to thin the components constituting the cells.

[0013] However, in a thinned cell, the effective cross-sectional area of the flow path through which the supplied reaction gas flows is reduced, and thus there is a problem that the discharge capacity of the generated water decreases.

[0014] Specifically, in the case where the unit cell includes the multi-perforated plate 32, since the reaction gas is forced to convect and diffuse in a turbulent manner, the generated water cannot be discharged smoothly compared to the discharge of a straight-shaped flow path. Thus, there is also a problem that since the generated water stagnates and the reaction gas cannot be supplied smoothly, the cell voltage decreases.

[0015] The above is only intended to help understand the background art of the present invention, and is not intended to mean that the present invention falls within the scope of related art well known to those skilled in the art. Summary of the Invention

[0016] The present invention relates to a multi-perforated plate for a separator of a fuel cell. A specific embodiment relates to a multi-perforated plate for a separator of a fuel cell, which can improve the discharge capacity of the generated water while maintaining excellent gas diffusion ability.

[0017] According to an exemplary embodiment of the present invention, a multi-perforated plate for a separator of a fuel cell is disposed between a separator having a flat plate shape and a gas diffusion layer to form a flow path for a reaction gas, and the multi-perforated plate includes: a porous region having an uneven shape repeatedly formed in the region and provided with a plurality of flow path holes to allow the reaction gas to flow in a turbulent manner; and a channel region forming a flow path to allow the reaction gas to flow in a straight line along the flow direction of the reaction gas, wherein the porous region and the channel region are alternately arranged and integrally formed.

[0018] The reaction gas can flow back and forth between the porous region and the channel region.

[0019] The channel region may include a pair of side surface portions and a contact surface portion formed between the pair of side surface portions to contact the gas diffusion layer; and the channel region may be open in the direction of the separator.

[0020] Each of the side surface portions may be provided with a plurality of first communication holes communicating with the porous region.

[0021] The contact surface portion may be provided with a plurality of second communication holes communicating with the gas diffusion layer.

[0022] The contact surface portion may be configured to be flat to make surface contact with the gas diffusion layer.

[0023] The porous region may be formed by processing a plate-like material having a plurality of flow path holes, and may be formed by repeatedly forming a corrugated cross-section along the flow direction of the reaction gas to form an uneven shape.

[0024] According to an exemplary embodiment of the present invention, in a perforated plate having a flow path through which a reaction gas and generated water flow, a porous region for guiding the reaction gas and the generated water to flow in a turbulent manner and a channel region for guiding the reaction gas and the generated water to flow in a straight line are alternately formed, thereby improving the discharge ability of the generated water while maintaining excellent gas diffusion ability.

[0025] In addition, since a channel region having a straight shape is formed as compared with the channel region of a conventional porous structure, the pressure difference between the inlet and the outlet of the reaction gas can be improved.

[0026] In addition, since communication holes through which the reaction gas and the generated water flow are formed between the channel region and the porous region, the supply of the reaction gas and the discharge of the generated water can be smoothly performed.

[0027] In addition, as compared with a conventional perforated plate structure, a flat portion in the channel region is ensured, so that damage to the gas diffusion layer due to direct contact during the lamination process can be suppressed.

[0028] Specifically, since the contact area between the perforated plate and the gas diffusion layer is ensured to be a wide surface, an effect of improving the distribution of the fastening force in the stack and reducing the contact resistance can be expected. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic view showing the structure of a general unit cell of a fuel cell using a conventional perforated plate.

[0030] Figure 2 is a schematic cross-sectional view showing a perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention.

[0031] Figure 3 is a schematic plan view of a multi-perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention.

[0032] Figure 4 is a schematic diagram showing the flow direction of reaction gas in a multi-perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention.

[0033] Figure 5A and Figure 5B are plan images showing multi-perforated plates according to a comparative example and an exemplary embodiment.

[0034] Figure 6A and Figure 6B are front images showing multi-perforated plates according to a comparative example and an exemplary embodiment. Detailed Embodiments

[0035] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the exemplary embodiments disclosed below, but can be implemented in various different forms. In addition, the exemplary embodiments are provided so that this disclosure will be thorough and complete, and the concept of the present invention will be fully conveyed to those skilled in the art. Throughout the drawings, the same reference numerals refer to the same components.

[0036] Figure 2 is a schematic cross-sectional view of a multi-perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention; Figure 3 is a schematic plan view of a multi-perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention; and Figure 4 is a schematic diagram showing the flow direction of reaction gas in a multi-perforated plate for a separator of a fuel cell according to an exemplary embodiment of the present invention.

[0037] As shown, a multi-perforated plate 100 for a separator of a fuel cell according to an exemplary embodiment of the present invention serves as a multi-perforated plate disposed between a flat separator 31 and a gas diffusion layer 20 to form a flow path for reaction gas, and the multi-perforated plate 100 includes a porous region 110 and a channel region 120. The porous region has an uneven shape repeatedly formed therein and is provided with a plurality of flow path holes 31a (see Figure 5A ) to allow the reaction gas to flow in a turbulent manner, and the channel region forms a flow path to allow the reaction gas to flow in a straight line along the flow direction of the reaction gas.

[0038] At this time, the multi-perforated plate 100 is configured as an integrated body having a porous region 110 and a channel region 120, and the porous region 110 and the channel region 120 are alternately arranged in a direction perpendicular to the flow direction of the reaction gas. In addition, the multi-perforated plate 100 is configured to allow the reaction gas to flow back and forth between the porous region 110 and the channel region 120.

[0039] More specifically, the multi-perforated plate 100 is formed by processing a plate-shaped metal material provided with a plurality of flow path holes 31a formed therein, as well as a plurality of first communication holes 123 and second communication holes 124 to be described later. For example, in the plate-shaped metal material, the plurality of flow path holes 31a are formed by punching in a predetermined pattern in a region corresponding to the porous region 110, and the plurality of first communication holes 123 and second communication holes 124 are formed by punching in a predetermined pattern in a region corresponding to the channel region 120. In addition, in a method using a mold formed in a protruding shape corresponding to the channel region 120, the region corresponding to the porous region 110 is formed in a shape corresponding to a waveform along the flow direction of the reaction gas, and the region corresponding to the channel region 120 is pressed by the plate-shaped metal material in which a plurality of flow path holes 31a, first communication holes 123, and second communication holes 124 are formed, thereby manufacturing the multi-perforated plate 100. Obviously, the method of manufacturing the multi-perforated plate 100 is not limited to the method presented herein, and various methods for manufacturing the presented multi-perforated plate are also applicable.

[0040] Meanwhile, the porous region 110 is a region corresponding to the shape of a conventional general multi-perforated plate 32 and is used to maintain excellent diffusion ability of the reaction gas. For this purpose, the channel region 120 has an uneven shape by repeatedly forming a waveform cross-section along the flow direction of the reaction gas, and is provided with a plurality of flow path holes 31a formed in various patterns (e.g., a zigzag pattern) to allow the reaction gas to flow in a turbulent manner. Therefore, as Figure 4 shown, the reaction gas as a whole flows from one side of the multi-perforated plate 100 to the other side, and diffuses while locally flowing irregularly from one side to the other side.

[0041] In addition, the channel region 120 is a region for promoting the discharge of the generated water and is provided with a straight-shaped flow path.

[0042] For example, the channel region 120 includes a pair of side surface portions 121 and a contact surface portion 122 formed between the pair of side surface portions 121 to contact the gas diffusion layer 20. Therefore, the channel region 120 has a substantially "U" - shaped cross-section. Thus, the contact surface portion 122 contacts the gas diffusion layer 20 and is open in the direction of the separator 31.

[0043] Meanwhile, while extending from the adjacent porous regions 110, side surface portions 121 of the channel region 120 are integrally formed. At this time, each of the side surface portions 121 is provided with a plurality of first communication holes 123 communicating with the porous regions 110, such that the reaction gas and the generated water can flow through each other in the porous regions 110. Accordingly, as Figure 4 shown, the reaction gas and the generated water flow through each other between the porous regions 110 and the channel region 120 through the first communication holes 123.

[0044] In addition, in the contact surface portion 122 of the channel region 120, a plurality of second communication holes 124 communicating with the channel region 120 are formed, such that the reaction gas and the generated water can flow through each other in the gas diffusion layer 20. Accordingly, the reaction gas flows from the channel region to the gas diffusion layer 20 through the second communication holes 124. In addition, the water generated in the membrane electrode assembly 10 passes through the gas diffusion layer 20, then flows into the channel region 120 through the second communication holes 124, and is then smoothly discharged through the channel region 120.

[0045] On the other hand, preferably, the contact surface portion 122 forming the channel region 120 is configured to be flat so as to make surface contact with the gas diffusion layer 20. Accordingly, a wide surface contact area between the perforated plate 100 and the gas diffusion layer 20 can be ensured, and thus the contact resistance between the perforated plate 100 and the gas diffusion layer 20 can be reduced.

[0046] Next, with reference to the drawings, a conventional general perforated plate structure (of the comparative example) is compared with the perforated plate structure (of the embodiment).

[0047] Figure 5A is a plan view showing a perforated plate according to the comparative example; Figure 5B is a plan view showing a perforated plate according to an exemplary embodiment; Figure 6A is a front view showing a perforated plate according to the comparative example; and Figure 6B is a front view showing a perforated plate according to an exemplary embodiment.

[0048] As Figure 5A and Figure 6A shown, in the comparative example which is a conventional general porous structure, only a structure corresponding to the porous region of the embodiment of the present invention is formed. Accordingly, although the diffusion ability of the reaction gas can be ensured, there may be a problem that the generated water cannot be smoothly discharged but stays.

[0049] In addition, since the perforated plate 32 formed in an uneven structure makes point contact or line contact with the gas diffusion layer 20, there may be a problem that the contact resistance increases in a specific region where contact occurs.

[0050] However, as Figure 5B and Figure 6B shown, in an exemplary embodiment of the multi-perforated plate structure according to the present invention, the porous regions 110 and the channel regions 120 are alternately formed, and a straight-shaped flow path is ensured within the channel regions 120, whereby the discharge capacity of the water generated in the multi-perforated plate 100 can be enhanced.

[0051] In addition, since the contact surface portion 122 of the channel region 120 makes surface contact with the gas diffusion layer 20, the contact area increases, and thus an effect that the contact resistance of the contact area may be reduced can be obtained.

[0052] Therefore, damage to the gas diffusion layer 20 can be prevented, and separation of the carbon fibers forming the gas diffusion layer 20 can be prevented, thereby also preventing damage to the membrane electrode assembly 10.

[0053] Although the present invention has been described with reference to the drawings and the above-described preferred exemplary embodiments, the present invention is not limited thereto, but is defined by the appended claims. Accordingly, those skilled in the art can make various modifications and changes to the present invention without departing from the scope of the technical spirit of the appended claims.

Claims

1. A multi-perforated plate for a separator of a fuel cell, the multi-perforated plate being designed to be disposed between a flat-shaped separator and a gas diffusion layer to form a flow path for a reaction gas, the multi-perforated plate comprising: A porous region having an uneven shape repeatedly formed in the porous region and provided with a plurality of flow path holes configured to allow the reaction gas to flow in a turbulent manner; And A channel region forming a flow path configured to allow the reaction gas to flow linearly along the flow direction of the reaction gas, wherein the porous region and the channel region are alternately arranged and integrally formed, Wherein the channel region includes a pair of side surface portions and a contact surface portion formed between the pair of side surface portions to contact the gas diffusion layer; and The channel region is open in the direction of the separator.

2. The multi-perforated plate according to claim 1, wherein, The reaction gas is configured to flow reciprocally between the porous region and the channel region.

3. The multi-perforated plate according to claim 1, wherein, Each of the side surface portions is provided with a plurality of first communication holes configured to communicate with the porous region.

4. The multi-perforated plate according to claim 1, wherein, The contact surface portion is provided with a plurality of second communication holes configured to communicate with the gas diffusion layer.

5. The multi-perforated plate according to claim 1, wherein, The contact surface portion is flat and makes surface contact with the gas diffusion layer.

6. A method for forming a porous region of the multi-perforated plate according to claim 1, the method comprising: Processing a plate-like material provided with a plurality of flow path holes formed in the plate-like material; And Repeatedly forming a corrugated cross-section along the flow direction of the reaction gas to form an uneven shape.

7. A fuel cell comprising: A membrane electrode assembly including an electrolyte membrane and a pair of electrodes disposed on opposite sides of the electrolyte membrane; A gas diffusion layer disposed on at least one side of the membrane electrode assembly; A separator disposed outside the gas diffusion layer; And A multi-perforated plate disposed between the separator and the gas diffusion layer, the multi-perforated plate comprising: A porous region having an uneven shape repeatedly formed in the porous region and provided with a plurality of flow path holes configured to allow a reaction gas to flow in a turbulent manner; and A channel region forming a flow path configured to allow the reaction gas to flow linearly along the flow direction of the reaction gas, wherein the porous region and the channel region are integrally formed and alternately arranged in the multi-perforated plate, Wherein the channel region includes: A pair of side surface portions; and A contact surface portion formed between the pair of side surface portions to contact the gas diffusion layer, Wherein the channel region is open in the direction of the separator.

8. The fuel cell according to claim 7, wherein, The separator has a flat shape.

9. The fuel cell according to claim 7, wherein, The porous region and the channel region are alternately arranged in a direction perpendicular to the flow direction of the reaction gas.

10. The fuel cell according to claim 7, wherein, The reaction gas is configured to flow reciprocally between the porous region and the channel region.

11. The fuel cell according to claim 7, wherein, Each of the side surface portions is provided with a plurality of first communication holes configured to communicate with the porous region.

12. The fuel cell according to claim 7, wherein, The contact surface portion is provided with a plurality of second communication holes configured to communicate with the gas diffusion layer.

13. The fuel cell according to claim 7, wherein, The contact surface portion is flat and makes surface contact with the gas diffusion layer.

14. A fuel cell, comprising: a membrane electrode assembly including an electrolyte membrane and a pair of electrodes disposed on opposite sides of the electrolyte membrane; a gas diffusion layer disposed on at least one side of the membrane electrode assembly; a separator disposed outside the gas diffusion layer; and a multi-perforated plate disposed between the separator and the gas diffusion layer, the multi-perforated plate including: a porous region having an uneven shape repeatedly formed in the porous region and provided with a plurality of flow path holes configured to allow a reaction gas to flow in a turbulent manner; and a channel region forming a flow path configured to allow the reaction gas to flow linearly along the flow direction of the reaction gas, the channel region including: a pair of side surface portions, each side surface portion being provided with a plurality of first communication holes configured to communicate with the porous region; and a contact surface portion formed between the pair of side surface portions to contact the gas diffusion layer and provided with a plurality of second communication holes configured to communicate with the gas diffusion layer, wherein the porous region and the channel region are integrally formed and alternately arranged in the multi-perforated plate.

15. The fuel cell according to claim 14, wherein, The channel region opens in the direction of the separator.

16. The fuel cell according to claim 14, wherein, The contact surface portion is flat and makes surface contact with the gas diffusion layer.

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