JP2018147716A - Terminal plate for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal plate for fuel cell, capable of achieving suppression of the complexity of a structure as well as high corrosion resistance of the plate part and suppression of heat generation of a terminal part.SOLUTION: The terminal plate includes: a plate part formed from a first metal facing a single cell constituting a fuel cell; a terminal part joined to an outer edge of the plate part and formed from a second metal outputting generated power of the fuel cell to the outside. The first metal has higher corrosion resistance than the second metal. The second metal has higher conductivity than the first metal. The plate part and the terminal part are joined to each other by either one of bolt joining and welding.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a terminal plate for a fuel cell.

  A terminal plate for a fuel cell stack comprising a conductive core plate having a terminal portion, a pair of corrosion-resistant plates that sandwich the core plate, and an adhesive seal material that maintains the sandwiched state of the core plate by the corrosion-resistant plates is known. (For example, Patent Document 1).

JP-A-2015-88294

  However, the conventional terminal plate needs to cover a part of the core plate and the corrosion-resistant plate with an adhesive seal material, and the structure is complicated. Therefore, there is a demand for a technology that can suppress the complexity of the structure of the terminal plate for a fuel cell. Conventionally, there is a demand for a technique capable of improving the corrosion resistance and reducing the heat generation of the terminal portion in the terminal plate.

  This indication is made in order to solve at least one part of the above-mentioned subject, and can be realized as the following forms.

According to one aspect of the invention, a terminal plate for a fuel cell is provided. The terminal plate is joined to a plate portion made of a first metal facing a single cell constituting the fuel cell and an outer edge portion of the plate portion, and outputs the generated power of the fuel cell to the outside. And a terminal portion made of two metals. The first metal has higher corrosion resistance than the second metal, the second metal has higher conductivity than the first metal, and the plate portion and the terminal portion are bolted, And any one of welding.
According to the terminal plate of the said form, a plate part is comprised with the 1st metal and the terminal part is comprised with the 2nd metal. Moreover, the plate part and the terminal part are joined by any one of bolt joining and welding. Therefore, since it is not necessary to use an adhesive seal material as compared with the conventional case, the structure of the terminal plate can be prevented from becoming complicated. In the terminal plate according to the above aspect, the plate portion that is likely to be corroded by liquid water is composed of the first metal having higher corrosion resistance than the second metal, and the terminal portion that is likely to generate heat due to current concentration is the first. The second metal is higher in conductivity than the first metal. Therefore, it is possible to improve the corrosion resistance of the plate portion and reduce the heat generation of the terminal portion with a simple structure that does not use an adhesive seal material.

  The present disclosure can be realized in various forms other than the terminal plate described above. For example, the present disclosure can be realized in the form of a fuel cell or a fuel cell system including the terminal plate.

1 is a schematic view of a fuel cell to which a terminal plate according to an embodiment is applied. The schematic diagram of the terminal plate concerning an embodiment. Sectional drawing of the terminal plate which concerns on embodiment. Sectional drawing of the terminal plate which concerns on a prior art example.

A. First Embodiment FIG. 1 is a schematic diagram illustrating a fuel cell 200 in which terminal plates 110a and 110b according to an embodiment of the present disclosure are used. The fuel cell 200 includes a pair of end plates 130a and 130b, a pair of insulating plates 120a and 120b, a pair of terminal plates 110a and 110b, and a plurality of single cells 100. The fuel cell 200 has a stack structure, and includes a first end plate 130a, a first insulating plate 120a, a first terminal plate 110a, a plurality of single cells 100, a second terminal plate 110b, The second insulating plate 120b and the second end plate 130b are stacked in this order. The single cell 100 is a solid polymer fuel cell that generates power by receiving supply of hydrogen gas as a fuel gas and air as an oxidizing gas. The electric power generated by the electrochemical reaction in the single cell 100 is taken out from the terminal plates 110a and 110b. The insulating plates 120a and 120b are formed of an insulating member such as rubber or resin. The end plates 130a and 130b are made of a metal such as steel and have rigidity. The fuel cell 200 is mounted on a moving body such as a vehicle and used as a power source for the moving body. The fuel cell 200 is also used as a stationary household power source.

  The fuel cell 200 has supply manifolds M1in to M3in used for supplying fuel gas or the like to the single cell 100, and discharge manifolds M1out to M3out used for discharging fuel gas or the like. The supply manifolds M1in to M3in include a fuel gas supply manifold M1in, an oxidizing gas supply manifold M2in, and a refrigerant supply manifold M3in. The discharge manifolds M1out to M3out include a fuel gas discharge manifold M1out, an oxidizing gas discharge manifold M2out, and a refrigerant discharge manifold M3out. The fuel gas supply manifold M1in supplies fuel gas, for example, hydrogen gas, to the single cell 100 from the outside. The fuel gas discharge manifold M1out discharges the fuel gas that has passed through the flow path of the single cell 100 to the outside. The oxidizing gas supply manifold M2in supplies an oxidizing gas, for example, air, to the single cell 100. The oxidizing gas discharge manifold M2out discharges the oxidizing gas that has passed through the flow path of the single cell 100 to the outside. The refrigerant supply manifold M3in supplies a refrigerant such as water to the single cell 100. The refrigerant discharge manifold M3out discharges the refrigerant that has passed through the flow path of the single cell 100 to the outside. The water used as the refrigerant is also referred to as cooling water.

  Terminal plate 110a, 110b has plate part 10a, 10b and terminal part 20a, 20b joined to the outer edge part 15 of plate part 10a, 10b. The terminal plates 110a and 110b are current collecting plates that collect the generated power of the single cell 100, and output the power collected from the terminal portions 20a and 20b to the outside. Hereinafter, the common features and effects of the first terminal plate 110a and the second terminal plate 110b will be described as the terminal plate 110. When the features and effects common to the first terminal plate 110a and the second terminal plate 110b are described for the plate portions 10a and 10b and the terminal portions 20a and 20b, which are the components of the terminal plates 110a and 110b, It describes as the plate part 10 and the terminal part 20. FIG.

  FIG. 2 is a schematic view of the terminal plates 110a and 110b. The first terminal plate 110a has manifold forming portions 11a to 13b that form manifolds M1in to M3out (FIG. 1) when stacked. Manifold formation parts 11a-13b form the opening which penetrates 110a. On the other hand, the second terminal plate 110b does not have a manifold forming portion. The fuel gas and the oxidizing gas supplied from the outside are supplied from the first terminal plate 110a to each single cell 100, and the fuel gas and the oxidizing gas that are not used for the reaction are folded back to the first terminal plate 110a. Return. Similarly, the cooling water is supplied from the first terminal plate 110a to each single cell 100 and returns to the first terminal plate 110a.

  The external shape of the plate part 10 is substantially rectangular. The terminal portion 20 is joined to the outer edge portion 15 of the plate portion 10. The terminal portion 20 is a member protruding from the outer edge portion 15. For the joining of the plate portion 10 and the terminal portion 20, for example, bolt joining that uses a bolt or welding, which is a joining method that does not use an adhesive seal material, can be used. Examples of the welding include friction welding, friction stir welding, and laser welding. In this embodiment, joining by welding is adopted.

  The outer shape of the first terminal plate 110a is substantially rectangular. A fuel gas inlet manifold forming portion 11a, an oxidizing gas inlet manifold forming portion 12a, and a cooling medium inlet manifold forming portion 13a are provided at one end in the longitudinal direction of the first terminal plate 110a. A fuel gas outlet manifold forming portion 11b, an oxidizing gas outlet manifold forming portion 12b, and a cooling medium outlet manifold forming portion 13b are provided at the other end in the longitudinal direction of the first terminal plate 110a.

  The external shape of the second terminal plate 110b is substantially rectangular. In FIG. 2, alternate long and short dash lines SL <b> 1 to SL <b> 5 shown in the plate portion 10 b represent positions where gaskets arranged in the opposing single cells 100 abut. A region surrounded by the alternate long and short dash lines SL1 to SL5 of the plate portion 10b functions as a manifold rear end portion 14 serving as an end portion of each of the manifolds M1in to M3out.

  A part of the cooling water supplied from the manifold forming portion 13a flows into a refrigerant flow path (not shown) formed by the plate unit 10 and the adjacent single cell 100, and faces the single cell 100 of the terminal plate 110. The side to be exposed is exposed to cooling water. Further, the manifold forming portion 11 b and the manifold rear end portion 14 are exposed to a fuel gas containing generated water generated by a chemical reaction in the single cell 100. Since the plate portion 10 is exposed to cooling water or generated water, the plate portion 10 is in an environment where corrosion is more likely to occur than the terminal portion 20.

  When the electric power generated by the single cell 100 is collected and output to the outside, the electric power concentrates on the terminal portion 20. The terminal portion 20 having a smaller cross-sectional area than the plate portion 10 is more likely to generate heat than the plate portion 10.

  The plate portion 10 and the terminal portion 20 are made of different types of metals. The plate part 10 is made of a first metal. The terminal part 20 is comprised with the 2nd metal of the kind different from a 1st metal. The first metal is a metal having higher corrosion resistance than the second metal. The second metal is a metal having higher conductivity (conductivity) than the first metal.

  As described above, the plate portion 10 is made of the first metal having higher corrosion resistance than the second metal. Therefore, when the plate portion 10 is exposed to cooling water or the like, the plate portion 10 can suppress the corrosion of the plate portion 10 as compared with the case where the plate portion 10 is made of the second metal like the terminal portion 20. it can. Here, the first metal constituting the plate portion 10 prevents or prevents the deterioration of the performance of the fuel cell 200 due to corrosion even when the terminal plate 110 is exposed to cooling water or the like and a current is applied. You may have the corrosion resistance of the grade which can be suppressed. Examples of the first metal having corrosion resistance include titanium and stainless steel. The degree of corrosion resistance can be evaluated based on, for example, an electrochemical test in which a current is passed through a sample immersed in hydrofluoric acid or the like. In this embodiment, titanium is adopted as the first metal.

  As described above, the terminal portion 20 is made of the second metal having higher conductivity than the first metal. Therefore, when the power concentrates, the terminal portion 20 can suppress heat generation as compared with the case where the terminal portion 20 is made of the first metal like the plate portion 10. Here, the second metal constituting the terminal portion 20 is conductive so that the terminal portion 20 does not reach a high temperature when the maximum current assumed in normal use of the fuel cell 200 is applied to the terminal plate 110. You may have. The high temperature means a temperature at which a problem such as deterioration of a member adjacent to the terminal plate 110 occurs. Examples of the second metal having conductivity include aluminum and copper. In this embodiment, aluminum is adopted as the second metal.

  Hereinafter, the structure of the first terminal plate 110a according to the embodiment and the structure of the first terminal plate 210 according to the conventional example will be compared using FIGS. FIG. 3 is a cross-sectional view of the first terminal plate 110a according to the embodiment. FIG. 4 is a cross-sectional view of a first terminal plate 210 according to a conventional example.

  As shown in FIG. 3, the first terminal plate 110a according to the embodiment has a structure in which a plate portion 10a and a terminal portion 20a are joined. On the side of the terminal plate 110a facing the single cell 100, a gasket GKa for preventing leakage of fuel gas, oxidizing gas, or refrigerant is disposed on the outer periphery of the manifold forming portions 11a to 13b. The gasket GKa is in contact with the unit cell 100 facing each other, and is held at the installation position by the surface pressure between the first terminal plate 110 a and the unit cell 100.

  As shown in FIG. 4, the first terminal plate 210 according to the conventional example has a structure in which the core plate 40 is sandwiched between a pair of corrosion-resistant plates 50, and a part of the core plate 40 is exposed from the corrosion-resistant plate 50. Thus, the terminal portion 80 is formed. The manifold forming portions 71a and 73a are sealed with an adhesive seal material 60 so that the core plate 40 does not directly contact the fuel gas, the oxidizing gas, or the refrigerant. In the conventional example, it is necessary to cover the core plate 40 with the adhesive sealant 60 and the corrosion-resistant plate 50. Therefore, the structure is complicated as compared with the embodiment.

  According to the terminal plate 110 of the embodiment described above, the plate portion 10 and the terminal portion 20 are each composed of a single metal (first metal or second metal). The plate part 10 and the terminal part 20 are joined by any one of bolt joining and welding. Since it is not necessary to use an adhesive seal material, the complexity of the structure of the terminal plate 110 can be suppressed as compared with the conventional case. In addition, the terminal plate 110 is made of the first metal having a high corrosion resistance and the plate portion 10 that is easily corroded when exposed to generated water or cooling water, and the terminal portion 20 that is likely to generate heat due to current concentration has a high conductivity. It is composed of two metals. Compared with a terminal plate made of only a metal having high corrosion resistance and low conductivity, such as a first metal, heat generation of the terminal portion 20 can be suppressed. Moreover, compared with the terminal plate comprised only with the metal with high electroconductivity and low corrosion resistance, for example, the 2nd metal, corrosion of the plate part 10 can be suppressed. Therefore, it is possible to improve the corrosion resistance of the plate portion 10 and reduce the heat generation of the terminal portion 20 with a simple structure that does not use an adhesive seal material.

  The present disclosure is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in the embodiments described in the summary section of the invention are intended to solve part or all of the above-described problems or to achieve one of the above-described effects. In order to achieve part or all, replacement or combination can be appropriately performed. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 70 ... Plate part 11a, 71a ... Fuel gas inlet manifold formation part 11b ... Fuel gas outlet manifold formation part 12a ... Oxidation gas inlet manifold formation part 12b ... Oxidation gas outlet manifold formation part 13a, 73a ... Cooling medium Inlet manifold forming portion 13b ... Cooling medium outlet manifold forming portion 14 ... Manifold rear end 15 ... Outer edge portion 20, 20a, 20b, 80 ... Terminal portion 40 ... Core plate 50 ... Corrosion-resistant plate 60 ... Adhesive sealant 100 ... Single cell 110 110a, 110b, 210 ... Terminal plate 120a, 120b ... Insulating plate 130a, 130b ... End plate GKa, GKb ... Gasket

Claims (1)

A terminal plate for a fuel cell,
A plate portion made of a first metal facing a single cell constituting the fuel cell;
A terminal portion that is joined to an outer edge portion of the plate portion and configured by a second metal that outputs the generated power of the fuel cell to the outside;
With
The first metal has higher corrosion resistance than the second metal,
The second metal is more conductive than the first metal,
The plate part and the terminal part are joined by any one of bolt joining and welding,
Terminal plate.

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