KR20080045417A - A manufacturing method and separator for embedded fuel cell - Google Patents

Abstract

An integrated fuel cell separator is provided to fundamentally prevent an outflow of coolant from a cooling channel, to produce a stack simply, and to improve airtight performance of a stack. A fuel electrode-cooling plane-air electrode integrated fuel cell separator includes: a separator cooling plane(1) coated with an adhesive; an adhesive-coated layer(2) formed by applying an adhesive onto the upside of the separator cooling plane; a cooling plane-fuel electrode separator(3) which is formed on the adhesive-coated layer and separates the cooling plane from the fuel electrode; and an air electrode-cooling plane separator(4) which is formed on the underside of the separator cooling plane and separates the air electrode from the cooling plane.

Description

Integrated fuel cell separator and its manufacturing method {A Manufacturing method and Separator for embedded fuel cell}

1 is a block diagram showing a fuel cell separator plate of the anode-cooling surface-air cathode of the present invention.

FIG. 2 is a block diagram illustrating a gasket, an air electrode, a cooling surface, a fuel electrode, and a gasket-integrated fuel cell separation plate integrated by bonding a gasket to FIG. 1.

Figure 3 is a block diagram showing a fixture for applying a separator adhesive of the present invention.

Figure 4 is a block diagram showing a separator cooling surface coated with the adhesive of the present invention.

5 is a block diagram showing that the fixing device for applying the adhesive of the present invention fixed on the separator plate cooling surface.

Figure 6 is a block diagram showing a fastener for applying a separator plate adhesive strip of Figure 1 removed.

Figure 7 is a block diagram showing an apparatus for fixing the separator adhesive applying fixture of the present invention to the separator plate cooling surface.

Explanation of symbols on the main parts of the drawing

1: Separation plate cooling surface 2: Adhesive coating layer

3: cooling surface-fuel electrode separator 4: air cathode-cooling electrode separator

5: Gasket layer (adhesive coating gasket layer) 6: Adhesive fastener

7: adhesive coating groove 8: manifold

9: cooling channel surface 10: connecting leg

11: adhesive uncoated surface 12: metal plate

13: fixing groove 14: manifold corner

15: fixing pin 16: rubber packing

The present invention relates to a fuel cell separator, and in particular, to combine and integrate oxygen or air-cooled separator and cold-fuel separator to improve the sealing performance of the fuel cell separator and to be suitable for simplifying stack fabrication. An integrated fuel cell separator and a method of manufacturing the same.

In general, a fuel cell uses a principle in which chemical energy of a fuel (hydrogen, methanol, etc.) is converted into electricity and thermal energy by using an electrochemical reaction. Fuel cells are solid oxide fuel cells (SOFCs), alkaline electrolyte fuel cells (AFCs), and polymer electrolyte membrane fuel cells (PEMFCs), depending on the type of fuel and reaction catalyst. , Hereinafter referred to as PEMFC), direct methanol fuel cell (DMFC, hereinafter referred to as DMFC), and the like, the present invention will be described for a separator having high applicability to PEMFC and DMFC. PEMFC and DMFC have a limitation in the temperature of use of the polymer electrolyte membrane used and are mainly used at a temperature of 80 degrees or less. In particular, the DMFC is known to be used at room temperature at a lower temperature of 50 degrees. For the operation of PEMFC and DMFC, components such as membrane electrode assembly (MEA, MEA), separation plate, current collector plate, and insulation plate are required.The separation plate is formed with a channel consisting of channels and ribs. Oxygen and air flow through the cathode, and hydrogen and methanol, which are fuels, flow through the anode.

Among the stack parts of fuel cells, metal separator plates and graphite separator plates are mainly used. In order to apply the separator to a fuel cell, electrical conductivity, gas permeability, strength, corrosion characteristics, dissolution characteristics, and the like must be considered. In order to apply a metal separator to a fuel cell, it is necessary to solve the corrosion problem, which is the most vulnerable characteristic, and since graphite separators are mostly used by machining, manufacturing costs are very high and bulky. Therefore, studies to solve this problem are ongoing.

For the stack application of graphite separators (including graphite composite separators) in fuel cells, the assembly process and condition of parts such as MEA, separator plate, and gasket are basically important. The fuel cell stack consists of an end plate, an insulating plate, a current collector plate, a separator plate, and a MEA. The anode / MEA / air electrode / cooling surface / fuel electrode is repeatedly stacked to meet the stack specifications. At this time, in order to reduce the volume of the stack, a cooling flow path is formed on the back of the cathode or, conversely, a cooling flow path is formed on the back of the anode. In addition, the cooling channel may be simultaneously formed on the back of the cathode and the back of the anode to reduce the volume of the fuel cell stack.

As the separator cooling surface is manufactured as described above, water flows inside to maintain the sealing performance. Basically, the gasket is manufactured like the electrode surface of the fuel cell to maintain the sealability, which takes a very long time to assemble the stack, and has a disadvantage of not maintaining the sealability according to the state of the gasket. The gasket for sealing the separator cooling surface has a problem that the mold for manufacturing the gasket must be made independently, and a lot of effort is required to give the precision of the gasket.

In addition, as a method for sealing the separator cooling surface, there is a method of discharging the adhesive at a constant pressure and curing to form a gasket. Makes it partially uneven. Therefore, there is often a case where the adhesiveness cannot be maintained at the overlapping portion, and there is a problem that the equipment for discharging the adhesive is additionally required.

Accordingly, the present invention has been invented to solve the above conventional problems, and the cathode-cooling separator and the cooling-fuel separator are bonded to the cooling channel side to form the cathode-cooling surface-fuel electrode as one unit cell, and thus the cooling channel. It is an object of the present invention to provide an integrated fuel cell separation plate and a method of manufacturing the same, which essentially prevent leakage of cooling water from and to easily manufacture a stack.

In addition, another object of the present invention is to provide a fuel cell separator and a method of manufacturing the same, in which a gasket is integrated into an air cathode-cooling plane-fuel separator to form a gasket-air cathode-cooling plane-fuel-gasket fuel cell separator. .

The present invention for achieving the above object, First, the separation plate cooling surface to which the adhesive is applied; An adhesive coating layer having an adhesive applied to an upper surface of the separating plate cooling surface; A cooling surface-fuel electrode separator formed on the adhesive coating layer to separate the cooling surface from the fuel electrode; And a cathode-cooling surface separator formed on a bottom surface of the separator cooling surface and separating the cathode and the cooling surface.

In addition, by applying and curing an adhesive to the integral fuel cell separator of the cathode-cooling surface-fuel electrode (also referred to as fuel electrode-cooling surface-air electrode), it is possible to perform the role of a gasket. A gasket layer is added to the cooling surface, the adhesive coating layer, the cooling surface-fuel separator, and the cathode-cooling separator to form a gasket-fuel electrode-cooling surface-air electrode-gasket integral fuel cell separator.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing a fuel cell separator plate of a fuel cell-cooling surface-air electrode integrated according to the present invention, and FIG. 2 is a gasket-air electrode-cooling surface-fuel electrode-gasket integrated fuel cell separating plate integrated by bonding a gasket to FIG. 1. The configuration diagram is shown.

1 and 2, a separator plate cooling surface 1 to which an adhesive is first applied; An adhesive coating layer (2) having an adhesive applied to an upper surface of the separating plate cooling surface (1); A cooling surface-fuel pole separating plate (3) formed on the adhesive coating layer (2) to separate the cooling surface from the fuel electrode; It is formed on the lower surface of the separator plate cooling surface (1) and comprises a cathode-cooling surface separator plate (4) separating the cathode and the cooling surface to form an anode-cooling surface-air electrode integrated fuel cell separator plate, and the adhesive is shown in FIG. A gasket layer (5) is added in addition to the separator cooling surface, the adhesive coating layer, the cooling surface-fuel electrode separation plate, the cathode-cooling surface separation plate and the gasket layer by applying and curing. -Form a cooling surface-air cathode-gasket integrated fuel cell separator.

3 to 7 are views illustrating a method of manufacturing the anode-cooling surface-air electrode integrated fuel cell separator plate and the gasket-fuel electrode-cooling surface-air electrode-gasket integrated fuel cell separator of FIGS. 1 and 2.

Figure 3 is a block diagram showing a fixture for applying a separator adhesive of the present invention.

As shown, the adhesive application fixture 6 for applying the adhesive on the separator cooling surface 1 cools the separator application groove 7 at the position where the adhesive is to be applied on the separator cooling surface 1. A hole was formed in the outer circumference of the manifold 8 and the cooling channel surface 9 formed on the surface 1 to connect the independently configured manifold 8, cooling channel surface 9 and the outermost part. In order to configure the connecting legs (10) having a width of 0.05 ~ 10mm.

In addition, the adhesive application fixture (6) is fixed on the separator plate cooling surface (1), and then the adhesive is applied on the adhesive application fixture (6) in a uniform height and width by a silk screen and screen printing method, wherein the application height is adhesive By adjusting the height of the application fixture 6 can be applied to 0.1 ~ 10mm. In detail, the height of the fastener 6 for adhesive application was made into 0.2-0.3 mm. The narrower the width of the connecting leg 10 for connecting the manifold 8, the cooling channel surface 9 and the outermost part, the wider the coating area of the adhesive formed on the separator plate, thereby improving the sealing performance. Therefore, the width of the connecting leg 10 was adjusted to 0.05 ~ 10mm, and in detail less than 1mm.

Further, after the adhesive applicable to the fuel cell is raised on the separator plate adhesive applying fixture 6, the adhesive is uniformly applied to the adhesive application groove 7 at the position where the adhesive is to be applied through the rubber squeegee. At this time, the adhesive is configured to have a uniform thickness and area on the separator cooling surface 1 by putting a film of 0.1 mm or less that is the same as the structure of the coating jig between the adhesive applying fixture 6 and the adhesive.

Figure 4 is a block diagram showing a separator cooling surface coated with the adhesive of the present invention.

As shown, the adhesive applied on the separator cooling surface (fuel-cooling, cooling-air) is bonded to the separator cooling surface (air-cooling, cooling-fuel) to which the adhesive is not applied, and thus room temperature according to the characteristics of the adhesive. Bonding for more than 24 hours at, or bonding from minutes to hours at a temperature of more than 100 degrees to produce an integral separator. For the above bonding process, a pressure of 10 psi or more is required. The adhesive non-coating surface 11, which is a portion where the adhesive is not applied at the bonding portion formed on the separator cooling surface 1, is spread out to the portion where the adhesive is not applied when pressure is applied in the process of fabricating the integrated separator plate and cooling the separator. Seal the face 1 completely.

5 is a configuration diagram showing that the fixing device for applying the adhesive of the present invention fixed on the separator plate cooling surface.

As shown, in order to fix the adhesive applying fixture 6 on the separator cooling surface 1, the adhesive applying fixture 6 is placed on the separator cooling surface 1 and then the separator cooling surface 1 The metal plate 12 is fixed below. At this time, the separation plate adhesive applying fixture (6) and the metal plate 12 is made wider than the separation plate cooling surface (1), forming a fixing groove 13 in the separation plate application fixture (6) and the metal plate (12) Make sure that the adhesive is applied on the separator plate cooling surface 1 in the correct position.

FIG. 6 is a diagram illustrating a fastener for applying a separator adhesive to which the connecting leg of FIG. 3 is removed.

As shown, in order to evenly apply the adhesive on the separator cooling surface 1, the connecting leg 10 of FIG. 3 is removed so that the adhesive is evenly applied to the entire area. Therefore, a device for fixing the adhesive applying fixture 6 is required for the separator adhesive applying fixture 6.

Figure 7 is a block diagram showing an apparatus for fixing the separator adhesive applying fixture of the present invention to the separator plate cooling surface.

As shown, as a device for fixing the adhesive applying fixture (6), connecting the fixing pin (15) having a length of 2mm or more to the edge portion 14 of the bottom of each manifold and the adhesive applying fixture (6) To the manifold (8) of the separation plate. Fixing pins 15 protruding to the bottom of the manifold 8 of the separator plate are fixed to the separator plate cooling surface 1 and the adhesive application fixture 6 using the rubber packing 16. The adhesive applying fixture 6 having the separator plate cooling surface 1 formed on the cooling channel surface 9 inserts the fixing pin 15 into the groove configured for the inflow and outflow of the cooling water to fix the adhesive applying fixture 6. . Using the adhesive and squeegee on the adhesive applying fixture 6 configured as described above, the adhesive is uniformly applied on the separator cooling surface.

The adhesive applied on the separator cooling surface (fuel-cooling or cooling-air) by the above methods is bonded to the separator cooling surface (air-cooling or cooling-fuel) to which the adhesive is not applied. Depending on the adhesive properties, the anode-cooling surface-air cathode integrated separator was manufactured by bonding at least 24 hours at room temperature or several minutes to several hours at a temperature of 100 degrees or higher. The cross-sectional structure of is shown in FIG. In addition, a pressure of 10 psi or more is required for the above bonding process.

In order to improve the anode-cooling surface-air cathode integrated fuel cell separator of FIG. 1, the adhesive applying fixture 6 is manufactured according to the structure of the anode and the cathode to select an adhesive suitable as a sealing material for the electrode surface of the fuel cell. The gasket-fuel electrode-cooling surface-air electrode-gasket integrated separator plate was manufactured using the same method as shown in FIG. 2. For gasket-fuel-cooling-air-gasket-integral separators, no pressure greater than 10 psi is required for the bonding process.

The following table shows the results obtained by comparing the thickness variation, the assembly time, and the permeation conductivity when manufactured by the existing method and the method of the present invention.

division Existing Method Invention method Thickness deviation ± 50㎛ ± 25㎛ Assembly time (based on 20cell stack) 30 minutes Within 10 minutes Transmission conductivity 0.829 mΩ 0.465 mΩ

As described above, the present invention has devised a separator for applying adhesive to the separator plate to uniformly apply the adhesive to the separator cooling surface, and through this separator adhesive applying fixture, the application process can be simplified and used for manufacturing the gasket. There is an effect that the mold and the equipment for discharging the adhesive is not required incidentally.

In addition, the adhesive uniformly configured through the separator adhesive application jig is completely cured at a pressure of 10 psi, so that the separator cooling surface is completely overlapped, so that the electrical conductivity required when the separator cooling surface is bonded is not significantly impaired. It works.

In addition, when assembling the stack by discharging the gasket and adhesive, the seal is often checked after the stack is completely configured. Therefore, when the stack cannot be sealed, the stack must be completely disassembled and then reassembled. Although inconvenience occurs, the present invention has the effect of confirming the sealing property of the cooling surface in advance before stack assembly.

In addition, the conventional stack assembly process requires a process of stacking a gasket between the separator cooling surfaces, so that the stack assembly time increases as the number of cells stacked in the stack increases, but as in the present invention, the separator is integrated. If manufactured to have an effect of shortening the stack assembly process.

Although the above has been described as being limited to the preferred embodiment of the present invention, the present invention is not limited thereto and various changes, modifications, and equivalents may be used. Therefore, the present invention can be applied by appropriately changing the above embodiment, it will be obvious that such application also belongs to the scope of the present invention based on the technical idea described in the claims.

Claims (12)

In the integrated fuel cell separator, A separator cooling surface 1 to which an adhesive is applied; An adhesive coating layer (2) having an adhesive applied to an upper surface of the separator plate cooling surface (1); A cooling surface-fuel electrode separating plate (3) formed on the adhesive coating layer (2) to separate the cooling surface from the fuel electrode; And a cathode-cooling surface separating plate (4) formed on a lower surface of the separating plate cooling surface (1) and separating the cathode and the cooling surface. The method of claim 1, By applying and curing an adhesive to the anode-cooling surface-air cathode integrated fuel cell separator, the separator serves as a gasket, an adhesive coating layer, a cooling surface-fuel separator, and an cathode-cooling. A gasket-fuel electrode-cooling surface-air electrode-gasket integral fuel cell separator, characterized in that a gasket layer (5) is additionally formed in addition to the face separator. After making the adhesive applying fixture 6 for applying the adhesive on the separator plate cooling surface 1, the adhesive applying fixture 6 is formed by a device for fixing the adhesive applying fixture 6 to the separator plate cooling surface ( 1) It is fixed on the adhesive plate, and the adhesive is evenly applied on the separator plate cooling surface 1 using an adhesive and a squeegee on the adhesive applying fixture 6, and is applied on the separator plate cooling surface (fuel-cooling or cooling-air). And the adhesive is bonded to the separator cooling surface (air-cooling or cooling-fuel) to which the adhesive is not applied to produce an anode-cooling surface-air cathode integrated fuel cell separator. The method of claim 3, wherein The adhesive applying fastener 6 has a manifold 8 and a cooling channel surface 9 formed on the separator cooling surface 1 with an adhesive applying groove 7, which is a position where the adhesive is to be applied on the separator cooling surface 1. To form a hole in the outer periphery of the), and to connect the manifold (8), the cooling flow path surface 9 and the outermost part formed independently of the width of the connecting legs (10) 0.05 ~ 10mm, in detail 1mm An integrated fuel cell separator manufacturing method, characterized in that below. The method of claim 3, wherein The adhesive applying fixture 6 is fixed on the separator plate cooling surface 1 and then the adhesive is applied on the adhesive applying fixture 6 in a uniform height and width by a silk screen and screen printing method, wherein the application height is adhesive applied. Adjusting the height of the fixing fixture (6) for coating up to 0.1 ~ 10mm, in detail, the manufacturing method of the integrated fuel cell separation plate, characterized in that the height of the adhesive fixing fixture (6) to 0.2 ~ 0.3mm. The method of claim 3, wherein An integrated fuel cell, characterized in that the adhesive is configured to have a uniform thickness and area on the separator cooling surface 1 by inserting a film of 0.1 mm or less that is the same as the structure of the coating jig between the adhesive applying fixture 6 and the adhesive. Separator manufacturing method. The method of claim 3, wherein The adhesive applied to the separator cooling surface (fuel-cooling, cooling-air) is bonded to the separator cooling surface (air-cooling, cooling-fuel) to which the adhesive is not applied, and at least 24 hours at room temperature according to the characteristics of the adhesive. A method of manufacturing an integrated fuel cell separator, the method comprising adhering or bonding at a temperature of 100 degrees or more for several minutes to several hours. The method of claim 7, wherein The bonding requires a pressure of 10 psi or more, and the adhesive non-coating surface 11, which is a portion where the adhesive is not applied at the bonding site configured on the separator cooling surface 1, is applied when this pressure is applied in the manufacturing process of the integrated separator plate. A method of manufacturing an integrated fuel cell separator, characterized in that it spreads to a portion where the adhesive is not applied to completely seal the separator plate cooling surface (1). The method of claim 3, wherein The separator plate adhesive applying fixture 6 and the metal plate 12 are made wider than the separator plate cooling surface 1, and the fixing groove 13 is formed in the separator plate applying fixture 6 and the metal plate 12. Method for producing a fuel cell separator plate, characterized in that the adhesive is applied on the separator plate cooling surface (1) in the correct position. The method of claim 3, wherein The device for fixing the adhesive applying fixture (6) is connected to a fixing pin (6) or more of the length of the edge portion 14 at the bottom of each manifold and the adhesive coating fixture (6) to the manifold (8) of the separation plate It is inserted into the site, the fixing pin (15) protruding to the bottom of the manifold (8) of the separator plate using the rubber packing (16) to secure the separator plate cooling surface (1) and adhesive applying fixture (6) An integrated fuel cell separator manufacturing method characterized in that. The method of claim 3, wherein The method of claim 1, wherein an adhesive is applied to the anode-cooling surface-air cathode integrated fuel cell separator to perform a role of a gasket. The method of claim 11, A method of manufacturing an integrated fuel cell separator, wherein a pressure of 10 psi or more is not required for bonding to apply and harden an adhesive to the anode-cooling surface-air cathode integrated fuel cell separator.

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