SEPARATOR UNIT FOR A FUEL CELL AND A UNIT CELL FOR A FUEL CELL INCLUDING SAME

Abstract

A unit cell for a fuel cell includes an electricity-generating assembly (EGA) in which a gas diffusion layer (GDL) is laminated on each of both sides of a membrane electrode assembly (MEA). The unit cell has a first separator and a second separator disposed on an outside of the EGA and a reaction surface is formed on each of the first and second separators through which a reactive gas flows. A cooling surface is formed on each of the first and second separators opposite the reaction surfaces and through which cooling water flows. A reaction surface gasket is formed on the reaction surface of the first separator, wrapping and fixing a top and bottom of the EGA, and forming an airtight line with the second separator. A cooling surface gasket is formed on the cooling surface of the first separator and forms an airtight line with a second separator of another unit cell disposed adjacent to the unit cell.

Claims

1. A separator unit used in a unit cell of a fuel cell, the separator unit comprising: a first separator having a reaction surface on which an electricity-generating assembly (EGA) is disposed and in which a gas diffusion layer (GDL) is laminated on each of both sides of a membrane electrode assembly (MEA), the reaction surface formed on a first side of the first separator and a cooling surface formed on a second side of the first separator; and a reaction surface gasket formed on the reaction surface of the first separator, wrapping and fixing a top and bottom of the EGA at a side of the EGA, and forming an airtight line with a second separator of the unit cell.

2. The separator unit claim 1, wherein the reaction surface gasket is divided into: an adhesive portion provided by being adhered to the reaction surface of the first separator; a hinge portion extended in a direction protruding from the adhesive portion; and a close contact portion bent and extended from an end of the hinge portion, wherein an insertion space is formed by the reaction surface gasket in which the side of the EGA is inserted by being surrounded by the adhesive portion, the hinge portion, and the close contact portion.

3. The separator unit claim 2, wherein at least one sealing protrusion is formed on the close contact portion, protruding in a direction opposite to the direction in which the hinge portion is formed,.

4. The separator unit claim 2, wherein the end of the close contact portion is in a form of a fillet.

5. The separator unit claim 1, wherein the reaction surface gasket is formed of an elastic rubber material.

6. The separator unit claim 1, further comprising: a cooling surface gasket formed on the cooling surface of the first separator, the cooling surface gasket forming an airtight line with a second separator of another unit cell disposed adjacent to the unit cell.

7. The separator unit claim 1, wherein the EGA further comprises a sub gasket that surrounds and supports an edge of the MEA, and wherein the reaction surface gasket wraps and fixes the top and bottom of the sub gasket.

8. A unit cell for a fuel cell, the unit cell comprising: an electricity-generating assembly (EGA) in which a gas diffusion layer (GDL) is laminated on each of both sides of a membrane electrode assembly (MEA); a first separator and a second separator disposed on an outside of the EGA, wherein a reaction surface through which a reactive gas flows is formed on a surface of each of the first separator and the second separator, facing the GDL, and wherein a cooling surface through which cooling water flows is formed on a surface, of each of the first separator and the second separator, opposite to the surface facing the GDL; a reaction surface gasket formed on the reaction surface of the first separator, wrapping and fixing a top and bottom of the EGA at a side of the EGA, the reaction surface gasket forming an airtight line with the second separator; and a cooling surface gasket formed on the cooling surface of the first separator, the cooling surface gasket forming an airtight line with a second separator of another unit cell disposed adjacent to the unit cell.

9. The unit cell of claim 8, wherein the reaction surface gasket is divided into: an adhesive portion provided by being adhered to the reaction surface of the first separator; a hinge portion extended in a direction protruding from the adhesive portion; and a close contact portion bent and extended from an end of the hinge portion, and is in close contact with the reaction surface of the second separator, wherein an insertion space is formed by the reaction surface gasket and in which the side of the EGA is inserted by being surrounded by the adhesive portion, the hinge portion, and the close contact portion.

10. The unit cell of claim 9, wherein at least one sealing protrusion is formed on the close contact portion, protruding in a direction opposite to the direction in which the hinge portion is formed, and is in close contact with the reaction surface of the second separator.

11. The unit cell of claim 9, wherein the end of the close contact portion is in a form of a fillet.

12. The unit cell of claim 11, wherein an exposed area in which the GDL is not disposed is formed at an edge of the EGA, and wherein the adhesive portion and the close contact portion surround the exposed area of the EGA.

13. The unit cell of claim 9, wherein the EGA further comprises a sub gasket that surrounds and supports an edge of the MEA, and wherein the reaction surface gasket wraps and fixes the top and bottom of the sub gasket.

14. The unit cell of claim 13, wherein, when the EGA and the second separator and the first separator are fastened, a height of the hinge portion corresponds to a stacked height of the MEA and the sub gasket.

15. The unit cell of claim 13, wherein, when the EGA and the second separator and the first separator are fastened, the reaction surface gasket is formed of an elastic rubber material, and wherein, as the hinge portion is elastically deformed, the sub gasket is clamped by the adhesive portion and the close contact portion.

16. The unit cell of claim 8, wherein a gasket for airtightness is not formed on the reaction surface and the cooling surface of the second separator.

17. The unit cell of claim 8, wherein the first separator is a cathode separator and the second separator is an anode separator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The above and other objectives, features, and other advantages of the present disclosure should be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0059] FIG. 1 is a view showing the configuration of a typical fuel cell stack;

[0060] FIG. 2A is a view showing an anode separator of the typical fuel cell stack;

[0061] FIG. 2B is a view showing a cathode reaction surface of a cathode separator of the typical fuel cell stack;

[0062] FIG. 2C is a view showing a cathode cooling surface of the cathode separator of the typical fuel cell stack;

[0063] FIG. 3 is a view showing a unit cell of the typical fuel cell stack;

[0064] FIG. 4 is a view showing the stacked state of the unit cells along the line A-A of FIG. 2B;

[0065] FIG. 5 is a view showing a separator unit for a fuel cell according to an embodiment of the present disclosure;

[0066] FIGS. 6A and 6B are views showing the stacked state of unit cells along the lines B-B and C-C of FIG. 5; and

[0067] FIGS. 7A and 7B are views showing the structure of a reaction surface gasket before and after fastening of unit cells for a fuel cell according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0068] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided so that the present disclosure is complete, and to fully inform those of ordinary skill the scope of the inventive concept. In the drawings, the same reference numerals refer to the same or equivalent elements. When a component, device, element, or the like of the present disclosure is described as having a purpose or performing an operation, function, or the like, the component, device, or element should be considered herein as being “configured to” meet that purpose or to perform that operation or function.

[0069] A unit cell according to an embodiment of the present disclosure maintains the configuration of the unit cell of a typical fuel cell stack shown in FIGS. 1 and 3 as it is. The unit cell adjusts the formation position and shape of a gasket formed on a separator selected from a pair of separators to increase the airtight stability of the unit cell.

[0070] In the unit cell according to the embodiment of the present disclosure, as shown in FIGS. 6A and 6B, and like in the unit cell for a fuel cell, a membrane electrode assembly 110 and an electricity-generating assembly (EGA) 100 are disposed between a pair of separators 210 and 220. In the EGA 100, a gas diffusion layer 130 is laminated or disposed on each of both sides of the membrane electrode assembly 110. Here, the electricity-generating assembly 100 may further include a frame that surrounds and supports the edge of the membrane electrode assembly 110, and this frame is referred to as a sub gasket 120.

[0071] Here, the pair of separators 210 and 220 comprise a first separator and a second separator. The first separator is a cathode separator 220 and the second separator is an anode separator 210.

[0072] Thus, a reaction surface of the anode separator 210 and a reaction surface of the cathode separator 220 are disposed on each side of the electricity-generating assembly 100, respectively.

[0073] In particular, in the unit cell for a fuel cell according to the embodiment of the present disclosure, a reaction surface gasket 300 and a cooling surface gasket 400, which are described below, may be formed on one of the anode separator 210 and the cathode separator 220.

[0074] In the embodiment, the formation of the reaction surface gasket 300 and the cooling surface gasket 400 on the cathode separator 220 is described as an example.

[0075] To elaborate, the reaction surface gasket 300 is injected and formed on the reaction surface of the cathode separator 220. The cooling surface gasket 400 is injected and formed on the cooling surface of the cathode separator 220.

[0076] The reaction surface gasket 300 and the cooling surface gasket 400 are not limited to being formed on the cathode separator 220. The reaction surface gasket 300 and the cooling surface gasket 400 may be formed on the anode separator plate 210.

[0077] In addition, a plurality of unit cells are connected in series to constitute a fuel cell stack.

[0078] The anode separator 210 configured in one unit cell is disposed to face the cathode separator 220 configured in the unit cell adjacent thereto.

[0079] In the following description, a redundant description of the unit cell for a typical fuel cell stack has been omitted.

[0080] FIG. 5 is a view showing a separator unit for a fuel cell according to an embodiment of the present disclosure. FIGS. 6A and 6B are views showing a stacked state of unit cells along the lines B-B and C-C of FIG. 5. FIGS. 7A and 7B are views showing the structure of a reaction surface gasket before and after fastening of unit cells for a fuel cell according to an embodiment of the present disclosure.

[0081] Here, FIG. 6A is a view showing a stacked state of unit cells along the line B-B of FIG. 5. FIG. 6B is a view showing a stacked state of unit cells along the line C-C of FIG. 5. FIG. 7A is a view showing the structure of a reaction surface gasket before fastening of unit cells for a fuel cell according to an embodiment of the present disclosure. FIG. 7B is a view showing the structure of a reaction surface gasket after fastening of unit cells for a fuel cell according to the embodiment of the present disclosure.

[0082] A separator unit for a fuel cell according to an embodiment of the present disclosure refers to the cathode separator 220 of the unit cell. The reaction surface gasket 300 and the cooling surface gasket 400 are formed by injection on the reaction surface and the cooling surface of the cathode separator 220, respectively.

[0083] The unit cell for a fuel cell according to the embodiment of the present disclosure is configured to include the above-described separator unit.

[0084] To elaborate, the unit cell for a fuel cell according to the embodiment of the present disclosure includes: a membrane electrode assembly (MEA) 110; a sub gasket 120 that surrounds and supports the edge of the membrane electrode assembly 110; a electricity-generating assembly (EGA) 100 having a pair of gas diffusion layers (GDL) 130 disposed on both sides of the MEA 110; and an anode separator 210 and a cathode separator 220 disposed on the outside of the GDL 130. A reaction surface through which a reactive gas flows is formed on a surface of each of the anode separator 210 and the cathode separator 220, facing the GDL 130. A cooling surface through which cooling water flows is formed on a surface of each of the anode separator 210 and the cathode separator 220, opposite to the surface facing the GDL.

[0085] Also, the unit cell for a fuel cell according to the embodiment of the present disclosure further includes a reaction surface gasket 300 formed on the reaction surface of the cathode separator 220. The reaction surface gasket 300 wraps and fixes the top and bottom of the sub gasket 120 at the side of the sub gasket 120. The reaction surface gasket 300 forms an airtight line with the anode separator 210. The unit cell for the fuel cell further includes a cooling surface gasket 400 formed on the cooling surface of the cathode separator 220. The cooling surface gasket 400 forms an airtight line with the anode separator 210 of another unit cell disposed adjacent to the formerly mentioned unit cell.

[0086] Here, the membrane electrode assembly 110, the sub gasket 120, the gas diffusion layer 130, the anode separator 210, and the cathode separator 220 maintain the configuration of the membrane electrode assembly 110, the sub gasket 120, the gas diffusion layer 130, the anode separator 210, and the cathode separator 220 of the fuel cell stack shown in FIGS. 1 and 3 as it is.

[0087] However, changes are made to the arrangement and shape of the gasket that is injected and formed on the cathode separator 220.

[0088] To elaborate, the cathode separator 220 has a reaction region 221. In the reaction region 221, a flow field through which air flows is formed in the central region, and a plurality of manifolds 222 are formed on both sides of the reaction region 221. Here, any one of the plurality of manifolds 222 is an air intake manifold 222 through which air is introduced.

[0089] A plurality of air flow channels 130 protrude and penetrate in the reaction surface direction so that the air introduced through the air intake manifold 222 passes from the cooling surface of the cathode separator 220 to the reaction surface and flows to the reaction area 221. The plurality of air flow channels 130 are formed in the cathode separator 220 between the air intake manifold 222 and the reaction region 221.

[0090] In addition, the reaction surface gasket 300 is formed on the reaction surface of the cathode separator 220 to form an airtight line contacting the anode separator 210 while surrounding the plurality of manifolds 222 and the reaction region 22.

[0091] On the cooling surface of the cathode separator 220, like on the cathode cooling surface of the cathode separator 32 shown in FIG. 2C, the cooling surface gasket 400 is formed. The cooling surface gasket 400 forms an airtight line in contact with the anode separator 210 while securing a path through which cooling water flows and a path through which air flows. Here, the cooling surface gasket 400 maintains an airtight line formed in the cathode separator in its pattern and shape.

[0092] Meanwhile, the reaction surface gasket 300 is a gasket that wraps and fixes the upper and lower ends of the sub gasket 120 while clamping the sub gasket 120 in the form of a clip on the side of the electricity-generating assembly 100, i.e., at the side of the sub gasket 120. The reaction surface gasket 300 forms an airtight line with the anode separator 210.

[0093] To this end, the reaction surface gasket 300 is divided into: an adhesive portion 310 provided by being adhered to the reaction surface of the cathode separator 220; a hinge portion 320 extended in the direction protruding from the adhesive portion 310; and a close contact portion 330 bent and extended from the end of the hinge portion 320. The reaction surface gasket 300 is in close contact with the reaction surface of the anode separator 210.

[0094] In particular, an insertion space 321 is formed in the reaction surface gasket 300 by being surrounded by the adhesive portion 310, the hinge portion 320, and the close contact portion 330. The side of the sub gasket 120 is inserted into the insertion space 321. Thus, the cross-section of the reaction surface gasket 300 is made in the form of a clip having an approximately “E” shape.

[0095] Meanwhile, in the close contact portion 330, at least one sealing protrusion 331 is formed, which protrudes in the opposite direction to the direction in which the hinge portion 320 is formed, i.e., in the direction of the anode separator 210 of the unit cell together. The at least one sealing protrusion 331 is in close contact with the reaction surface of the anode separator 210.

[0096] Here, it is desirable that the sealing protrusion 331 is formed at both ends of the close contact portion 330 and is in close contact with the anode separator 210 while having a uniform surface pressure by the close contact portion 330.

[0097] Also, it is desirable that the end of the close contact portion 330 is formed in the form of a fillet 332.

[0098] In particular, an exposed area in which the gas diffusion layer 130 is not disposed is created at the edge of the sub gasket 120. Because the fillet 332 structure is formed at the end of the close contact portion 330, the close contact portion 330 is aligned while surrounding the exposed area of the sub gasket 120.

[0099] Similar to the close contact portion 330, the adhesive portion 310 also is aligned while surrounding the exposed area of the sub gasket 120.

[0100] Meanwhile, as shown in FIGS. 7A and 7B, the reaction surface gasket 300 is formed of an elastic rubber material. Thus, while the membrane electrode assembly 110, the sub gaskets 120, the pair of gas diffusion layers 130, the anode separator 210, and the cathode separator 220 are fastened, the hinge portion 320 is elastically deformed and the sub gasket 120 is clamped and fixed by the adhesive portion 310 and the close contact portion 330.

[0101] Here, it is desirable that the height of the hinge portion 320 is elastically deformed corresponding to the height at which the membrane electrode assembly 110 and the sub gasket 120 are stacked.

[0102] Therefore, airtightness is maintained between the anode separator 210 and the membrane electrode assembly 110 by the close contact portion 330 of the reaction surface gasket 300. Airtightness is also maintained between the cathode separator 220 and the membrane electrode assembly 110 by the adhesive portion 310 of the reaction surface gasket 300. Airtightness is further maintained between the anode separator 210 and the cathode separator 220 by the adhesive portion 310, the hinge portion 320, and the close contact portion 330 of the reaction surface gasket 300.

[0103] Since it is possible to maintain airtightness between the anode separator 210 and the membrane electrode assembly 110, airtightness between the cathode separator 220 and the membrane electrode assembly 110, and airtightness between the anode separator 210 and the cathode separator 220 by the reaction surface gasket 300 formed by being injected into the cathode separator 220, there is no need to form a separate means for maintaining airtightness in the anode separator 210 of the unit cell for a fuel cell according to the present disclosure.

[0104] Therefore, a gasket for airtightness is not formed on the reaction surface and the cooling surface of the anode separator 210.

[0105] Although the present disclosure has been described with reference to the accompanying drawings and the foregoing embodiments, the present disclosure is not limited thereto but is defined by the claims set forth below. Therefore, those having ordinary skill in the art can variously change and modify the present disclosure without departing from the technical spirit of the present inventive concept provided by the following claims.