JP2005353413A - Current collector and fuel cell having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collector for a fuel cell of which the wear can be suppressed, and also to provide a fuel cell using the collector. <P>SOLUTION: A collector for a fuel cell has a surface for contacting to the electrode of a fuel cell, and further has a portion for increasing contacting surface pressure between the surface portion of the collector and the electrode of the fuel cell. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a current collector and a fuel cell having the current collector.

  In recent years, fuel cells have attracted attention as a new electric energy source. This fuel cell may use a film-like electrode (hereinafter also referred to as an electrode film) made of a metal or a metal oxide, and collects electrons from the electrode film or supplies electrons to the electrode. Current collectors are provided for power distribution. As such a current collector, a metal mesh or carbon cloth made of stainless steel or the like, and one made of a scouring metal fiber as shown in Patent Document 1 below are used.

JP-A-6-36783

  However, all of the above-described conventional current collectors are formed in a fiber shape, and thus there is a problem that the electrode film is damaged and worn by point contact with the electrode film. When the electrode film is worn in this way, the film resistance of the electrode film is partially unbalanced, causing a problem that the battery performance of the fuel cell is lowered.

  The above-mentioned problem is a problem that can occur not only when the electrode is in the form of a membrane but also when the electrode is in a porous (porous) form.

  This invention is made | formed in view of the said subject, and it aims at providing the electrical power collector which can suppress abrasion with respect to an electrode, and a fuel cell having the same.

In order to achieve at least part of the above object, a fuel cell current collector of the present invention is a current collector used in a fuel cell,
The gist of the present invention is to have a contact surface pressure increasing portion that has a surface portion that contacts the electrode of the fuel cell and increases the contact surface pressure between the surface portion and the electrode.

  According to the configuration of the fuel cell, since the surface portion of the current collector is in contact with the electrode, it is possible to suppress the electrode from being worn by the current collector.

In the fuel cell current collector,
The electrode is formed in a film shape,
In the contact surface pressure increasing portion,
The surface portion may be in surface contact with the electrode formed in a film shape.

  In this way, since the current collector and the electrode are in surface contact, it is possible to prevent the electrode from being worn by the current collector.

In the fuel cell current collector,
Consists of metal plates,
You may make it raise the contact surface pressure of the surface part of the said metal plate, and the said electrode using the heat_generation | fever accompanying the action | operation of the said fuel cell.

  In this way, in the operating temperature range of the fuel cell, it is possible to increase the contact surface pressure between the surface portion of the metal plate and the electrode in the current collector, so that the current collector and the electrode due to secular change, thermal deterioration, etc. It is possible to prevent the contact surface pressure from decreasing.

In the fuel cell current collector,
In the contact surface pressure increasing portion,
The metal plate is composed of a first metal plate having the surface portion and a second metal plate,
You may make it provide the gas layer thermally expanded in the operating temperature range of the said fuel cell enclosed between the said 1st metal plate and the said 2nd metal plate.

  By doing so, the enclosed gas layer is thermally expanded in the operating temperature range of the fuel cell, and accordingly, the surface portion of the first metal plate is pushed up to the electrode side. The contact surface pressure between the surface portion of the metal plate and the electrode can be increased. Further, when the temperature of the fuel cell is lower than the operating temperature range, the push-up of the first metal plate due to the thermal expansion of the gas layer is reduced, so that the surface portion of the first metal plate and the electrode are unnecessarily necessary. The secular change of the 1st metal plate resulting from raising the contact surface pressure in between can be suppressed.

In the fuel cell current collector,
The first metal plate may be convex, and the top portion may be the surface portion.

In the fuel cell current collector,
In the contact surface pressure increasing portion,
The metal plate has a bimetal structure including a first metal plate having the surface portion and a second metal plate, and the second metal plate has a thermal expansion coefficient higher than that of the first metal plate. May be made higher.

  In this way, the first metal plate is pushed by the second metal plate due to the difference in thermal expansion between the first metal plate and the second metal plate in the operating temperature range of the fuel cell. The contact surface pressure between the surface portion of the metal plate (first metal plate) and the electrode in the current collector can be increased.

The fuel cell current collector is:
The shape of the metal plate having a bimetal structure may be a step shape, and the top portion may be the surface portion.

In order to achieve at least a part of the above object, the fuel cell of the present invention is a fuel cell,
First and second electrodes;
An electrolyte membrane sandwiched between the first and second electrodes;
A current collector of the fuel cell in contact with the first electrode;
The main point is that

  According to the configuration of the fuel cell, since the surface portion of the current collector is in contact with the first electrode, it is possible to suppress wear of the electrode by the current collector.

In the fuel cell,
The first electrode may be composed of a hydrogen permeable metal film.

Hereinafter, the embodiment of the present invention will be described based on the following procedure.
A. First embodiment:
A1. Fuel cell configuration:
A2. Current collector configuration:
A3. Effects of the embodiment:
B. Second embodiment:
B1. Fuel cell configuration:
B2. Current collector configuration:
B3. Effects of the embodiment:
C. Variations:

A. First embodiment:
A1. Fuel cell configuration:
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a single cell 500 which is a structural unit of a fuel cell in a first embodiment of the present invention. The fuel cell in the present embodiment has a stack structure in which a plurality of single cells 500 are stacked and connected in series. The single cell 500 is formed on the current collector 100, the anode electrode 10, the hydrogen permeable metal layer 15, the electrolyte layer 20 formed on the surface of the hydrogen permeable metal layer 15, and the electrolyte layer 20. A cathode electrode 30 and a current collector 40 disposed on the cathode electrode 30 are provided. Hereinafter, the structure in which the anode electrode 10, the hydrogen permeable metal layer 15, the electrolyte layer 20, and the cathode electrode 30 are laminated is also referred to as MEA (Membrane-Electrode Assembly) 70, and further, on both sides of the MEA 70. A structure in which the current collector 100 and the current collector 40 are formed is also referred to as a multilayer body 75. The single cell 500 further includes two gas separators 50 and 60 that sandwich the multilayer body 75 from both sides.

  The current collector 40 is made of a gas-permeable member formed by weaving fibers made of a conductive material. The current collector 40 has a function of distributing electrons supplied from the separator 50 to the cathode electrode 30. The conductive material forming the current collector 40 is only required to be stable in the internal environment of the fuel cell and to be formed into a fiber shape. For example, metals such as stainless steel (SUS) and titanium (Ti), carbon Etc. Therefore, the current collector 40 can be formed of, for example, a metal mesh or carbon cloth. Between the gas separator 50 and the current collector 40, an in-single cell oxidizing gas channel 90 through which an oxidizing gas containing oxygen passes is formed.

  On the other hand, the current collector 100 is composed of two metal plates as will be described later. The current collector 100 is provided between the gas separator 60 and an anode electrode 10 made of a metal film, which will be described later. The current collector 100 is in contact with each of the anode electrode 10 and the gas separator 60 and generates electrons generated by the anode electrode 10. Is collected and supplied to the gas separator 60. Between the anode electrode 10 provided with the current collector 100 and the gas separator 60, the gas separator 60 also has a function as a fuel gas flow path 80 in a single cell through which a fuel gas containing hydrogen passes. Details of the current collector 100 will be described later.

  The hydrogen permeable metal layer 15 is a layer formed of a metal having hydrogen permeability, and is made of, for example, a group 5 metal such as vanadium (V) (in addition to V, niobium, tantalum, etc.) or an alloy of a group 5 metal. It is formed.

  The anode electrode 10 is formed into a dense film by a metal having activity of separating hydrogen molecules and hydrogen permeability, such as palladium (Pd) or palladium (Pd) alloy. The anode electrode 10 is formed on the hydrogen permeable metal layer 15 by physical vapor deposition (PVD), chemical vapor deposition (CVD), plating (for example, aerosol deposition method) or the like.

The electrolyte layer 20 is a layer made of a solid electrolyte having proton conductivity. As the solid electrolyte constituting the electrolyte layer 20, for example, BaCeO ₃ or SrCeO ₃ based ceramic proton conductors can be used. The electrolyte layer 20 can be formed on the hydrogen permeable metal layer 15 by generating the solid electrolyte. As a method of forming the electrolyte layer 20, various methods such as PVD and CVD can be used, for example. Thus, by forming the electrolyte layer 20 on the dense hydrogen permeable metal layer 15, the electrolyte layer 20 can be sufficiently thinned. By reducing the thickness of the electrolyte layer 20, the membrane resistance of the electrolyte layer 20 can be further reduced, and the fuel cell can be operated at about 200 to 600 ° C., which is lower than the operating temperature of the conventional solid electrolyte fuel cell. It becomes possible to drive.

  The cathode electrode 30 is a layer including a material having catalytic activity that promotes an electrochemical reaction. In the present embodiment, the cathode electrode 30 is provided by forming a porous (porous) thin platinum (Pt) layer on the electrolyte layer 20. The platinum (Pt) layer that becomes the cathode electrode 30 is formed by, for example, PVD or CVD.

  The gas separators 50 and 60 are gas-impermeable plate-like members made of a conductive material such as carbon or metal. On the surface of the gas separator 50, a predetermined concavo-convex shape for forming the oxidizing gas flow path 90 in the single cell is formed. The uneven portion of the gas separator 50 is in contact with the current collector 40. Therefore, electrons sent from the anode electrode side are distributed to the current collector 40 via the gas separator 50. The gas separator 50 is preferably formed of the same material as the current collector 40 in contact with the separator. On the other hand, the current collector 100 is joined to the surface of the gas separator 60 by brazing. Therefore, the electrons supplied from the current collector 100 are transmitted to the cathode electrode side through the gas separator 60. Moreover, it is good also as providing a refrigerant flow path between the adjacent single cells 500 in a fuel cell stack.

Although not shown in FIG. 1, the fuel cell stack penetrates in the stacking direction in the fuel cell stack, and a fuel gas supply manifold, a fuel gas discharge manifold, an oxidizing gas supply manifold, and an oxidizing gas discharge manifold. Is provided. When fuel gas is supplied to the fuel cell stack, the fuel gas is distributed to each in-cell fuel gas flow path 80 via the fuel gas supply manifold and used for the electrochemical reaction, and then the fuel gas discharge manifold. Are gathered together and guided to the outside. Further, when the oxidizing gas is supplied to the fuel cell stack, the oxidizing gas is distributed to the oxidizing gas flow paths 90 in each single cell via the oxidizing gas supply manifold, and is supplied to the electrochemical reaction, and thereafter the oxidizing gas. Collected in the discharge manifold and guided to the outside.
Now, the current collector 100 will be described below.

A2. Current collector configuration:
FIG. 2 is a schematic cross-sectional view illustrating a schematic configuration of the current collector 100 in the present embodiment. As shown in the figure, the current collector 100 in this embodiment is composed of two metal plates 110 and 120, each of which is made of stainless steel (SUS). In the current collector 100, the metal plate 110 is formed in a convex shape and the metal plate 120 is formed in a flat shape, and a portion other than the convex portion of the metal plate 110 and a portion corresponding to that of the metal plate 120 are brazed. It is joined. The top surface of the convex portion of the metal plate 110 is in surface contact with the anode electrode 10 made of a metal film. Further, air is enclosed in a space surrounded by the convex portion of the metal plate 110 and the metal plate 120 to form an air layer 130. In FIG. 1, the height of the current collector 100 in the z direction is shown to be smaller than the thickness of the MEA 70 in the z direction, but in reality, the height of the current collector 100 in the z direction is It is about 4 to 5 times the thickness of the MEA 70. As shown in FIG. 2, in the metal plate 120, the surface opposite to the bonding surface with the metal plate 110 is bonded to the gas separator 60.

  FIG. 3 is a schematic arrangement view of each convex portion in the current collector 100 of the present embodiment. This figure is a diagram showing the AA ′ cross section in FIG. 1 from the z direction. As shown in the figure, the convex portions of the current collector 100 are arranged on the gas separator 60 in a staggered manner. In this way, the fuel gas (hydrogen gas) is smoothly supplied to the anode electrode 10.

A3. Effects of the embodiment:
As described above, the current collector 100 in the present embodiment is configured by forming the convex metal plate 110 on the surface of the flat metal plate 120, and the top surface of the convex portion of the metal plate 110 is a metal film. It is comprised so that it may be in surface contact with the anode electrode 10 which consists of (FIG. 1). In this way, wear of the anode electrode 10 by the current collector 100 can be suppressed.

  Further, in the present embodiment, in the current collector 100, air is enclosed in a space surrounded by the convex portions of the metal plate 110 and the metal plate 120 to form an air layer 130 (FIG. 2). In this way, when the fuel cell is operated and the temperature in the fuel cell rises, the air layer 130 thermally expands, whereby the top surface of the convex portion of the current collector 100 (metal plate 110) is in the z direction. The contact surface pressure between the top surface of the convex portion of the current collector 100 and the anode electrode 10 can be increased. As a result, it is possible to prevent a decrease in contact surface pressure between the current collector 100 and the anode electrode 10 due to secular change, thermal deterioration, or the like. Further, after that, when the operation of the fuel cell is finished and the temperature thereof is lower than the operating temperature range, the push-up of the top surface of the convex portion of the current collector 100 due to the thermal expansion of the air layer 130 is reduced. Therefore, the contact surface pressure between the top surface of the convex portion of the current collector 100 and the anode electrode 10 is not increased unnecessarily, and the secular change of the metal plate 110 on the top surface of the convex portion of the current collector 100 is achieved. And heat deterioration can be suppressed.

  As described above, conventionally, a fibrous current collector has been used as a current collector for collecting electrons from the anode electrode 10. In this case, in addition to the problems described above, there is also a problem that a part of the current collector falls off due to deterioration, and this prevents the gas flow in the gas flow path. On the other hand, the current collector 100 of the present embodiment uses two metal plates 110 and 120. In this way, unlike the conventional fibrous current collector, a part of the current collector does not fall off due to deterioration, and as a result, the gas collector in the gas flow path is caused by the dropped current collector. Does not obstruct the flow.

B. Second embodiment:
Next, a second embodiment of the present invention will be described. The fuel cell of the present embodiment is different from the fuel cell of the first embodiment in the following points. That is, in the fuel cell of the first embodiment, the current collector on the anode electrode side is formed by joining a convex metal plate and a flat metal plate and enclosing air between the metal plates. However, the fuel cell of the present example uses a plurality of the current collectors on the anode electrode side which are formed by joining two metal plates having different thermal expansion coefficients. Therefore, in the following, the present embodiment will be described focusing on differences from the first embodiment.

B1. Fuel cell configuration:
FIG. 4 is a schematic cross-sectional view showing a schematic configuration of a single cell 500 ′ which is a structural unit of the fuel cell in the second embodiment of the present invention. The single cell 500 ′ in the present embodiment has almost the same configuration as the single cell 500 in the first embodiment, but as shown in the figure, the single cell 500 ′ in the present embodiment has the same structure as the first cell 500 ′. Instead of the current collector 100 of the example, a plurality of current collectors 100 ′ are used.
The current collector 100 ′ will be described below.

B2. Current collector configuration:
FIG. 5 is a schematic cross-sectional view showing a schematic configuration of the current collector 100 ′ in the present embodiment. As shown in the figure, the current collector 100 ′ in this example has a bimetallic structure composed of two metal plates 110 ′ and 120 ′ having different thermal expansion coefficients, and the metal plate 110 ′ is made of stainless steel. Made of steel (SUS), the metal plate 120 ′ is made of copper (Cu), which has a higher coefficient of thermal expansion than stainless steel. In the current collector 100 ′, the metal plate 110 ′ and the metal plate 120 ′ have substantially the same step shape (step shape), and the metal plate 110 ′ is joined to the metal plate 120 ′ with a clat material. Yes. In the current collector 100 ′, the K portion shown in the drawing is called a step portion, and the H portion is called a holding portion. The top surface of the step portion of the metal plate 110 ′ is in surface contact with the anode electrode 10 made of a metal film. In FIG. 4, the height of the current collector 100 ′ in the z direction is shown to be smaller than the thickness of the MEA 70 in the z direction, but actually the height of the current collector 100 ′ in the z direction is z It is about 4 to 5 times the thickness of the MEA 70 in the direction. As shown in FIG. 5, the metal plate 120 ′ and the gas separator 60 are brazed and joined at the holding portion of the current collector 100 ′. Thereby, the current collector 100 ′ is held by the gas separator 60.

  In the step portion of the current collector 100 ′, the slope between the top surface and the holding portion is referred to as a slope portion. As shown in FIG. 4, each of the current collectors 100 ′ described above has a slope portion opposed to the fuel gas flow direction (x direction), and the top surface portion is downstream of the holding portion in the fuel gas flow direction. It is installed to be on the side. In this way, the fuel gas is smoothly supplied to the anode electrode 10 along the slope portion of the current collector 100 ′.

  FIG. 6 is a schematic layout diagram of the current collector 100 ′ in the present embodiment. This figure is a diagram showing the BB ′ cross section in FIG. 4 from the z direction. As shown in the figure, the current collectors 100 ′ are arranged on the gas separator 60 in a staggered manner. In this way, the fuel gas (hydrogen gas) is smoothly supplied to the anode electrode 10.

B3. Effects of the embodiment:
As described above, the current collector 100 ′ in this embodiment is configured by joining two step-shaped metal plates 110 ′ and 120 ′, and the top surface of the step portion of the metal plate 110 ′ is made of metal. The anode electrode 10 made of a film is configured to be in surface contact (FIG. 4). In this way, wear of the anode electrode 10 due to the current collector 100 ′ can be suppressed.

  Further, the current collector 100 ′ in this embodiment has a step-like bimetal structure including a metal plate 110 ′ and a metal plate 120 ′ having a higher coefficient of thermal expansion than the metal plate 110 ′. (FIG. 5). In this way, when the fuel cell is activated and the temperature in the fuel cell rises, the metal plate 120 ′ expands more thermally than the metal plate 110 ′, thereby collecting the current collector 100 ′ (metal plate 110 ′). The top surface of the step portion in FIG. 5 is pushed up in the z direction, and the contact surface pressure between the top surface of the step portion of the current collector 100 ′ and the anode electrode 10 can be increased. As a result, it is possible to prevent a decrease in contact surface pressure between the current collector 100 ′ and the anode electrode 10 due to aging, thermal degradation, and the like. On the other hand, when the operation of the fuel cell ends and the temperature becomes lower than the operating temperature range, the pushing-up in the z direction of the top surface of the step portion of the current collector 100 ′ due to thermal expansion is reduced. Accordingly, the contact surface pressure between the top surface of the step portion of the current collector 100 and the anode electrode 10 is not increased unnecessarily, and the aging of the metal plate 110 ′ on the top surface of the step portion of the current collector 100 is aged. Changes and thermal degradation can be suppressed.

  Further, the current collector 100 ′ of the present embodiment uses two metal plates 110 ′ and 120 ′. In this way, unlike the conventional fibrous current collector, a part of the current collector is not dropped due to deterioration, and as a result, the gas flow in the gas flow path is reduced by the dropped current collector. There is no hindrance.

C. Variation:
The present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the scope of the invention.

C1. Modification 1:
In the above embodiment, the separator 60 is treated as a separate member from the current collectors 100 and 100 ′. However, the present invention is not limited to this, and the separator 60 is also a part of the current collector 100 or 100 ′. May be handled.

C2. Modification 2:
In the first embodiment, the current collector 100 is joined to the gas separator 60, and the top surface of the convex portion of the current collector 100 is configured to contact the anode electrode 10. It is not limited to. The current collector 100 may be bonded to the anode electrode 10 so that the top surface of the current collector 100 is in surface contact with the gas separator 60. In this case, the current collector 100 is configured to have a large number of holes in portions other than the convex portions so that the fuel gas can contact the anode electrode 10. In this way, since the current collector 100 is in surface contact with the anode electrode 10, wear of the anode electrode 10 by the current collector 100 can be suppressed. In this way, when the fuel cell is operated and the temperature in the fuel cell rises, the air layer 130 thermally expands, whereby the top surface of the convex portion of the current collector 100 (metal plate 110) becomes z. The contact surface pressure between the top surface of the convex portion of the current collector 100 and the separator 60 can be increased. As a result, the contact surface pressure between the current collector 100 and the anode electrode 10 also increases, so that it is possible to prevent a decrease in the contact surface pressure between the current collector 100 and the anode electrode 10 due to secular change or thermal degradation.

C3. Modification 3:
In the second embodiment, the current collector 100 ′ is joined to the gas separator 60, and the top surface of the step portion of the current collector 100 ′ is configured to come into contact with the anode electrode 10. Is not limited to this. In the current collector 100 ′, the holding portion may be joined to the anode electrode 10, and the top surface of the current collector 100 ′ may be in contact with the gas separator 60. In this way, since the current collector 100 ′ (holding portion) is in surface contact with the anode electrode 10, the wear of the anode electrode 10 by the current collector 100 ′ can be suppressed. In this way, when the fuel cell is operated and the temperature in the fuel cell rises, the metal plate 120 ′ expands more thermally than the metal plate 110 ′, and thereby the current collector 100 ′ (metal plate 110). The top surface of the step portion in ') is pushed up in the z direction, and the contact surface pressure between the top surface of the step portion of the metal plate 110 ′ and the gas separator 60 can be increased. As a result, the contact surface pressure between the current collector 100 ′ and the anode electrode 10 also increases, so that it is possible to prevent a decrease in the contact surface pressure between the current collector 100 ′ and the anode electrode 10 due to aging, thermal degradation, and the like. it can.

C4. Modification 4:
In the first embodiment, the two metal plates 110 and 120 constituting the current collector 100 are made of stainless steel (SUS), but the present invention is not limited to this. For example, the metal plates 110 and 120 may be made of iron (Fe), copper (Cu), or the like. Further, the metal plate 110 and the metal plate 120 may be made of different metals.

C5. Modification 5:
In the first embodiment, the current collector 100 encloses air between the metal plate 110 and the metal plate 120 to form the air layer 130. However, the present invention is not limited to this. Instead of air, oxygen gas (O ₂ ), nitrogen gas (N ₂ ), carbon dioxide gas (CO ₂ ), or the like may be enclosed.

C6. Modification 6:
In the above embodiment, the anode electrode 10 is formed of palladium (Pd) or a palladium (Pd) alloy, but the present invention is not limited to this. For example, the anode electrode 10 may be formed of ruthenium (Ru). The anode electrode 10 may be formed of a material other than metal. For example, the anode electrode 10 can be formed by a mixed conductor having proton conductivity and electron conductivity. As such a mixed conductor, for example, a SrZrO ₃ -based or BaCeO ₃ -based solid oxide or tungsten oxide (WO ₃ ) can be used. This solid oxide can exhibit electronic conductivity in addition to proton conductivity by adjusting the composition of the constituent elements.

C7. Modification 7:
In the above embodiment, the cathode electrode 30 is formed in a porous shape. However, the present invention is not limited to this, and may be formed in a film shape in the same manner as the anode electrode 10. In this case, as a material for forming the film, a metal such as palladium (Pd), palladium (Pd) alloy, or ruthenium (Ru) having catalytic activity for promoting an electrochemical reaction and also having proton conductivity is used. . Further, the cathode electrode 30 is formed in a film shape from the mixed conductor described in the modification 6 or the mixed conductor having oxide ion conductivity and electron conductivity (for example, BaPrCoO ₃ -based solid oxide). You may make it do.

C8. Modification 8:
In the embodiment or the modification example 7, the fibrous current collector 40 is used as the current collector on the cathode electrode 30 side, but the present invention is not limited to this, and the current collector 40 is not limited to this. Instead, the current collector 100 or 100 ′ in the above embodiment may be further used. When the current collector 100 is used, the metal plate 110 may be bonded to the gas separator 50 and the top surface may be in surface contact with the cathode electrode 30, or the metal plate 110 may be connected to the cathode electrode 30. The top surface may be in surface contact with the gas separator 50. When the current collector 100 ′ is used, the holding portion may be bonded to the gas separator 50 and the top surface may be in surface contact with the cathode electrode 30, or the holding portion may be bonded to the cathode electrode 30. The top surface may be in surface contact with the gas separator 50.

C9. Modification 9:
In the above embodiment, the MEA 70 has the hydrogen permeable metal layer 15, but this may be omitted.

C10. Modification 10:
The current collector 100 ′ in the second embodiment is composed of a metal plate 110 ′ made of stainless steel (SUS) and a metal plate 120 ′ made of copper (Cu), but the present invention is limited to this. It is not a thing. The metal plate 120 ′ only needs to have a higher thermal expansion coefficient than the metal plate 110 ′. The metal plate 120 ′ may be made of Cu, Cu—Zn, Ni—Mn—Fe, Ni—Cr—Fe, austenite (SUS304, 316), or the like. In this case, the current collector 100 ′ can be formed as a bimetal structure of any combination of the metal plate 110 ′ and the metal plate 120 ′. Further, each of the metal plate 110 ′ and the metal plate 120 ′ is formed by adding nickel (Ni) to a base material made of stainless steel (SUS), and the Ni is interposed between the metal plate 110 ′ and the metal plate 120 ′. The coefficient of thermal expansion of the metal plate 120 ′ may be made higher than that of the metal plate 110 ′ by adjusting the addition amount. In this case, the amount of Ni added to the metal plate 110 ′ is made smaller than the amount of Ni added to the metal plate 120 ′. As described above, even when the current collector 100 ′ is formed, the effect of the second embodiment can be obtained.

It is a cross-sectional schematic diagram which shows schematic structure of the single cell 500 which is a structural unit of the fuel cell in a 1st Example. It is a cross-sectional schematic diagram which shows schematic structure of the electrical power collector 100 in a 1st Example. It is a schematic arrangement | positioning figure of each convex part in the electrical power collector 100 of a 1st Example. It is a cross-sectional schematic diagram which shows schematic structure of single cell 500 'which is a structural unit of the fuel cell in a 2nd Example. It is a cross-sectional schematic diagram which shows schematic structure of collector 100 'in a 2nd Example. It is a schematic layout of current collector 100 ′ in the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Anode electrode 15 ... Hydrogen permeable metal layer 20 ... Electrolyte layer 30 ... Cathode electrode 40 ... Current collector 50, 60 ... Gas separator 70 ... MEA
75 ... Multi-layer body 80 ... Fuel gas flow path in single cell 90 ... Oxidation gas flow path in single cell 100, 100 '... Current collector 110, 120, 110', 120 '... Metal plate 500,500 '... Single cell

Claims (9)

A current collector used in a fuel cell,
A current collector for a fuel cell, comprising: a surface portion in contact with the electrode of the fuel cell; and a contact surface pressure increasing portion for increasing a contact surface pressure between the surface portion and the electrode. The current collector of the fuel cell according to claim 1,
The electrode is formed in a film shape,
In the contact surface pressure increasing portion,
The collector of a fuel cell, wherein the surface portion is in surface contact with the electrode formed in a film shape. The current collector of the fuel cell according to claim 1 or 2,
The contact surface pressure increasing portion is
Consists of metal plates,
A current collector for a fuel cell, wherein the contact surface pressure between the surface portion of the metal plate and the electrode is increased using heat generated by the operation of the fuel cell. The current collector of the fuel cell according to claim 3,
In the contact surface pressure increasing portion,
The metal plate is composed of a first metal plate having the surface portion and a second metal plate,
A fuel cell current collector, comprising: a gas layer thermally expanded in an operating temperature range of the fuel cell, which is enclosed between the first metal plate and the second metal plate. The current collector of the fuel cell according to claim 4,
The current collector of the fuel cell, wherein the first metal plate has a convex shape, and a top portion thereof serves as the surface portion. The current collector of the fuel cell according to claim 3,
In the contact surface pressure increasing portion,
The metal plate has a bimetal structure including a first metal plate having the surface portion and a second metal plate, and the second metal plate has a thermal expansion coefficient higher than that of the first metal plate. A current collector of a fuel cell characterized by having a high value. The current collector of the fuel cell according to claim 6,
A current collector for a fuel cell, wherein the metal plate having a bimetal structure has a step shape, and a top portion thereof serves as the surface portion. A fuel cell,
First and second electrodes;
An electrolyte membrane sandwiched between the first and second electrodes;
The current collector according to any one of claims 1 to 7, which is in contact with the first electrode;
A fuel cell comprising: The fuel cell according to claim 8, wherein
The fuel cell, wherein the first electrode is formed of a hydrogen permeable metal film.

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