Manufacturing method of fuel cell

Abstract

This invention provides a technology for forming an adhesive layer with high precision at a specific location on a separator. [Solution] A method for manufacturing a fuel cell cell comprises the steps of cooling a separator for a fuel cell and applying an adhesive to the cooled separator to form an adhesive layer on the surface of the separator.

Description

Technical Field

[0001] This specification discloses a technique related to a method for manufacturing a fuel cell.

Background Art

[0002] Patent Document 1 discloses a fuel cell in which a separator and a seal member are joined by an adhesive layer. In Patent Document 1, a thermoplastic resin containing a crystalline polymer is used to join the separator and the seal member. Specifically, the thermoplastic resin is disposed between the separator and the seal member, heated to melt the thermoplastic resin, and then cooled to cure the thermoplastic resin to form an adhesive layer, thereby joining the separator and the seal member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the manufacturing method of Patent Document 1, when heated, the thermoplastic resin may wet and spread. That is, it may move to parts other than the place where the thermoplastic resin is disposed, and an adhesive layer may be formed in an unintended place. For example, when the adhesive layer is formed in the power generation part of the separator or the like, the contact resistance may increase or the voltage monitoring quality may be adversely affected. Therefore, a technique for suppressing the formation of an adhesive layer in an unintended place is required. This specification aims to provide a technique for accurately forming an adhesive layer at a specific place on the separator.

Means for Solving the Problems

[0005] This specification discloses a technology relating to a method for manufacturing a fuel cell cell. This manufacturing method may include the steps of cooling a separator for a fuel cell and applying an adhesive to the cooled separator to form an adhesive layer on the surface of the separator.

[0006] In the above configuration, by applying the adhesive to a pre-cooled separator, the viscosity of the adhesive increases the moment it comes into contact with the separator surface, which suppresses the wetting and spreading of the adhesive on the separator surface. As a result, it is possible to prevent the adhesive from forming in unintended locations on the separator. [Brief explanation of the drawing]

[0007] [Figure 1] The external view of the separator is shown. [Figure 2] The method for manufacturing the adhesive layer of this embodiment is shown. [Figure 3] This shows a conventional method for manufacturing adhesive layers. [Modes for carrying out the invention]

[0008] Referring to Figure 1, the separator 10 will be described. The separator 10 is placed between each cell of the fuel cell. The separator 10 is provided with an air inlet hole 2, an air outlet hole 14, a hydrogen gas inlet hole 8, a hydrogen gas outlet hole 6, a cooling water inlet hole 12, and a cooling water outlet hole 4. The inlet holes 2, 8, and 12 are located at one end of the separator 10. The outlet holes 4, 6, and 14 are located at the other end of the separator 10. A fuel passage 16 is formed in the central part of the separator 10. The fuel passage 16 is formed by grooves provided on the surface of the separator 10.

[0009] A sealing member, such as a resin frame or gasket, is joined to the separator 10 to seal air, hydrogen gas, and coolant. The separator 10 and the sealing member are joined by applying adhesive around the inlet holes 2, 8, 12, outlet holes 4, 6, 14, and fuel passage 16, thereby forming an adhesive layer between the separator 10 and the sealing member.

[0010] Figure 2 shows a manufacturing method for forming an adhesive layer 20 on the AA cross-section of Figure 1. First, before applying the adhesive to the separator 10, the separator 10 is cooled to ±10°C of the glass dislocation temperature of the adhesive. Cooling of the separator 10 can be carried out, for example, by passing it through a cooling device immediately before applying the adhesive to the separator 10. Furthermore, the cooling method and structure of the cooling device are not limited, such as air cooling or liquid cooling, as long as it has the capacity to cool the separator 10 to a temperature that increases the viscosity of the adhesive.

[0011] After cooling the separator 10, an adhesive is applied to the surface of the separator 10 as shown in (a) to form an adhesive layer 20. The adhesive in contact with the surface of the separator 10 is cooled to ±10°C of the glass transition temperature, and its viscosity increases. As a result, the wetting and spreading of the adhesive is suppressed, and the adhesive layer 20 is formed in the intended location on the separator 10 as shown in (b). Subsequently, a sealing member or the like is placed on the surface of the separator 10, and the separator 10 and the sealing member or the like are joined by the curing of the adhesive layer 20. In this way, by cooling the separator 10 before applying the adhesive to the separator 10, the area in which the adhesive layer 20 is formed can be precisely controlled. As a result, it is possible to suppress an increase in contact resistance and prevent adverse effects on voltage monitoring quality, etc., thereby suppressing a decrease in fuel cell performance.

[0012] Furthermore, by arranging the cooling device and the adhesive application device in close proximity, the time from cooling the separator 10 to applying the adhesive to the separator 10 can be shortened, and the time until the adhesive comes into contact with the separator 10 can be shortened. In other words, the time required to form the adhesive layer 20 can be shortened, and consequently, the manufacturing time of the fuel cell can be shortened.

[0013] Figure 3 shows a manufacturing method for forming an adhesive layer 20 on the AA cross-section of Figure 1 using a conventional method. In the conventional manufacturing method, the separator 10 is not cooled before applying the adhesive to the separator 10. Therefore, even if the adhesive is applied to the position shown in (a) to form the adhesive layer 20, the low viscosity of the adhesive causes the adhesive to wet and spread across the surface of the separator 10 as shown in (b), forming an adhesive layer 20 in unintended locations. If an adhesive layer 20 is formed in unintended locations, it can lead to increased contact resistance, adverse effects on voltage monitoring quality, etc., and a decrease in the performance of the fuel cell.

[0014] Furthermore, even with conventional methods, adjusting the viscosity of the adhesive (increasing its viscosity) can suppress the wetting and spreading of the adhesive on the surface of the separator 10. However, increasing the viscosity of the adhesive reduces the discharge performance of the adhesive application device, making it difficult to apply the adhesive to the surface of the separator 10 at high speed. As a result, the time required to form the adhesive layer 20 on the surface of the separator 10 increases, and the manufacturing time of the fuel cell increases.

[0015] Generally, the viscosity of adhesives such as acrylics is temperature-dependent. That is, the lower the temperature, the higher the viscosity, and the higher the temperature, the lower the viscosity. Therefore, adhesives at a favorable temperature (high temperature) in the coating process have low viscosity and are prone to wetting and spreading. On the other hand, adhesives at temperatures where wetting and spreading are less likely (low temperature) have high viscosity and poor coatability. In this embodiment, the manufacturing method cools the separator 10, thereby lowering the viscosity of the adhesive during the coating process and increasing the viscosity of the adhesive on the surface of the separator 10. Therefore, the adhesive coating process can be sped up (fuel cell manufacturing time can be shortened) while maintaining the quality (performance) of the fuel cell.

[0016] Although embodiments of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. Furthermore, the technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]

[0017] 10: Separator, 20: Adhesive layer

Claims

[Claim 1] A process for cooling the separator for fuel cells, The process involves applying an adhesive to the cooled separator to form an adhesive layer on the surface of the separator, A method for manufacturing a fuel cell equipped with

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