JP2003282127A - Cell stack and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell stack and a fuel cell enhancing current collecting characteristics between cells of the fuel cell. <P>SOLUTION: Each of plate-shaped current collecting members 43 is arranged between facing cells 33 of the fuel cell of a plurality of cells, facing cells are electrically connected, the plate-shaped current collecting member 43 is formed in a Z shape as viewed in the gas flowing direction, and each end of the plate- shaped current collecting member is brought into contact with each outer surface of the facing cells 33 of the fuel cell. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell stack and a fuel cell, and more particularly to a cell stack and a fuel cell which have good current collecting characteristics of a plurality of fuel cells.

[0002]

2. Description of the Related Art In recent years, various fuel cells in which a plurality of fuel cells are housed in a container have been proposed as next-generation energy.

A conventional solid oxide fuel cell is constructed by accommodating a plurality of fuel battery cells in a container and electrically connecting the fuel battery cells to each other in series or in parallel by a current collecting member. Was performed at a high temperature of about 600 to 1000 ° C. by supplying the oxygen-containing gas and the fuel gas to the fuel cell.

As a current collecting member for electrically connecting the fuel cells, a metal felt-like member in which fibrous metals are gathered is conventionally used. A fuel cell using such a felt-shaped current collecting member has a plurality of fuel cells arranged and assembled, and for example, between an interconnector of one fuel cell and an outer electrode of the other fuel cell. The fuel cell was packed in a felt-like current collecting member in series to form a cell stack, and the cell stack was housed in a housing container.

[0005]

However, in the above fuel cell, since the felt-shaped current collecting member is made of fibrous metal, the interconnector of one fuel cell and the fuel cell of the other fuel cell are formed. However, there was a problem that the current collecting characteristics were still low due to the point contact with the outer electrode.

Further, even if the current collecting member is packed between the fuel cells, the contact with the fuel cell is not sufficiently made due to vibrations or deterioration of elasticity of the current collecting member, so that the current collecting characteristics at the beginning of power generation. Was likely to decrease with time even if it was good to some extent.

Furthermore, when an oxygen-containing gas such as air is introduced between the fuel cells to generate electricity, the surface of the fibrous metal is oxidized to reduce the current collecting characteristics and the elastic force of the metal felt. However, there is also a problem that the characteristics deteriorate over time.

Further, when the current collecting member is packed between the interconnector of one fuel battery cell and the outer electrode of the other fuel battery cell, the current collecting member has a felt shape, so There is also a risk that the outer electrodes of the fuel cell and the other fuel cell may be electrically connected to each other.

An object of the present invention is to provide a cell stack and a fuel cell which can improve current collecting characteristics between fuel cells.

[0010]

In the cell stack of the present invention, plate-like current collecting members are arranged between a plurality of arranged fuel cells, and the opposing fuel cells are electrically connected to each other. At the same time, the plate-shaped current collecting member is Z-shaped when viewed from the gas flow direction, and both ends thereof are brought into contact with the outer surfaces of the fuel cell units facing each other.

In such a cell stack, the plate-shaped current collecting member has a Z-shape, and both ends of the plate-shaped current collecting member are in contact with the outer surfaces of the opposing fuel cells, and are in surface contact with the outer surfaces of the fuel cells. The area in contact with the fuel cell is larger than that of the conventional felt-shaped current collecting member, and the current collecting characteristics can be improved.

Further, since the plate-shaped current collecting member mainly made of metal or alloy has a spring property, it has a large elastic force, and even if vibration or the like occurs, sufficient contact with the fuel cell unit can be secured for a long period of time. Further, since the current collecting member is plate-shaped, it is more difficult to sinter than the conventional felt-shaped current collecting member even when the temperature inside the storage container is high, and the sufficient contact with the fuel battery cell is prolonged. The period can be secured.

Further, since the current collecting member is plate-shaped, for example, when the current collecting member is packed between the interconnector of one fuel battery cell and the outer electrode of the other fuel battery cell, one fuel It is possible to reliably prevent conduction between the outer electrodes of the battery cell and the other fuel cell.

Further, in the cell stack of the present invention, it is desirable that the fuel cells are flat and the outer surfaces of the opposing fuel cells are substantially flat. As described above, when the outer surfaces of the fuel cells facing each other are substantially flat, both end portions of the plate-shaped current collecting member are surely brought into contact with the flat portions of the outer surface of the fuel cell, so that the current collecting characteristic can be improved.

Further, in the cell stack of the present invention, it is desirable that the plate-shaped current collecting member is provided with irregularities at the contact portion with the outer surface of the fuel cell unit. In a cell stack like this,
The contact portion of the plate-shaped current collector member having the unevenness comes into contact with the outer surface of the opposing fuel battery cell. However, on the outer surface of the fuel battery cell, the protrusion of the contact portion of the plate-shaped current collector member is formed. Abut,
Since a space is formed between the outer surface of the fuel cell and the convex portion of the contact portion, and the gas will pass through this space, the supply of gas to the outer electrode surface is increased, and The amount of gas supplied to the solid electrolyte through the high quality outer electrode can be increased, and power generation performance can be improved.

In particular, a corrugated unevenness is formed in the contact portion of the plate-shaped current collecting member with the outer surface of the fuel cell, and the recess formed in the contact portion is formed in the gas flow direction. desirable. In this case, the gas passes between the concave portion formed in the abutting portion of the plate-shaped current collector and the outer surface of the outer electrode, the supply of gas to the outer electrode surface can be increased, and the power generation performance can be improved.

Further, in the cell stack of the present invention, in the fuel cell, a solid electrolyte and an outer electrode are sequentially formed on the surface of the inner electrode having gas passage holes formed in the axial direction, and the solid electrolyte and the outer electrode are formed. An interconnector is formed on the surface of the inner electrode on which no electrode is formed, and both ends of the plate-shaped current collecting member are in contact with the interconnector of one fuel battery cell and the outer electrode of the other fuel battery cell. It is characterized by being As described above, it is preferably used when the fuel cells are electrically connected in series.

Further, in the cell stack of the present invention, the fuel cell has an outer electrode exposed to an oxygen-containing gas, and the plate-shaped current collecting member has an acid-resistant surface of a metal or alloy having conductivity. It is desirable that it is coated with a chemical substance. Since the plate-shaped current collecting member has oxidation resistance, the plate-shaped current collecting member can have good electrical conductivity even when exposed to the oxygen-containing gas.

Further, in the cell stack of the present invention, it is desirable that both ends of the plate-shaped current collecting member are joined to the outer surfaces of the fuel cell units facing each other with a conductive paste. As a result, the electrical connection between the plate-shaped current collecting member and the fuel cell unit can be reliably performed. When the plate-shaped current collecting member has irregularities at both ends, the convex portions are bonded to the outer surface of the fuel cell unit by the conductive paste.

The fuel cell of the present invention is characterized in that the above cell stack is housed in a housing container. In such a fuel cell, since the cell stack has good current collecting characteristics, excellent power generating characteristics can be exhibited.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the fuel cell of the present invention, in which reference numeral 31 indicates a storage container having a heat insulating structure. Inside the storage container 31, a cell stack 35 in which a plurality of fuel battery cells 33 are assembled, a combustion chamber 37 formed above the cell stack 35, and an oxygen-containing gas supply pipe 39 that passes through the combustion chamber 37. And the combustion chamber 3
7 and a heat exchange portion 41 provided above the heat exchanger 7.

The storage container 31 includes a frame 31a made of heat-resistant metal and a heat insulating material 3 provided on the inner surface of the frame 31a.
1b and.

As shown in FIG. 2, the cell stack 35 in the storage container 31 is formed by arranging the fuel cells 33 in three rows, and the two outermost fuel cells 3 arranged adjacently are arranged.
The electrodes of 3 are connected to each other by the conductive member 42.
A plurality of fuel cells 33 arranged in rows are electrically connected in series. It should be noted that FIG. 1 shows four columns.

More specifically, the fuel cell 33 has a flat cross section and an elliptic column shape as a whole, and a plurality of fuel gas passage holes 34 are formed inside the fuel cell 33. The fuel cell 33 has a flat cross section, and has an elliptic columnar shape as a whole, and a dense solid electrolyte 33b is formed on the outer surface of a fuel-side electrode (inner electrode) 33a containing a porous metal as a main component.
An oxygen side electrode (outer side electrode) 33c made of porous conductive ceramics is sequentially laminated, and an interconnector 33d is formed on the outer surface of the fuel side electrode 33a opposite to the oxygen side electrode 33c. The electrode 33a serves as a support.

That is, the cross section of the fuel cell 33 is
It is composed of arc-shaped portions provided at both ends in the width direction and a pair of flat portions that connect these arc-shaped portions. The pair of flat portions are flat and are formed substantially parallel to each other. These pair of flat portions are formed on the flat portion of the fuel side electrode 33a by the interconnector 33d, the solid electrolyte 33b, or the oxygen side electrode 3.
3c is formed.

A plate-shaped collector member 43 is interposed between the one fuel battery cell 33 and the other fuel battery cell 33, and the fuel side electrode 33a of the one fuel battery cell 33 is connected to the fuel side electrode 33a. It is electrically connected to the oxygen-side electrode 33c of the other fuel cell 33 via the interconnector 33d and the plate-shaped current collecting member 43 provided. In addition, in FIG. 2, the plate-shaped collector member 43 is illustrated in a simplified manner.

The plate-shaped current collecting member 43, as shown in FIG.
It is configured by bending a rectangular plate into a Z shape, and both ends thereof are substantially parallel. That is, the plate-shaped current collecting member 43 has a connecting portion 43a formed in the central portion for applying a spring, and substantially parallel contact portions 43 formed on both sides of the connecting portion 43a.
b, and the contact portions 43b formed at both ends of the plate-shaped current collecting member 43 have opposed fuel cell units 33.
Abutting on the outer surface of each.

A corrugated unevenness is formed on the contact portion 43b of the plate-shaped current collecting member 43, and a recess 43b1 formed on the contact portion 43b is formed in the gas flow direction. Figure 3
In (b), the gas flow direction is perpendicular to the paper surface. The gas passes between the recess 43b1 formed in the contact portion 43b of the plate-shaped current collector 43 and the outer surface of the oxygen-side electrode 33c, so that the supply of the gas to the surface of the oxygen-side electrode 33c can be increased to improve the power generation performance. Can be improved.

A plurality of plate-shaped current collecting members 43 are arranged between the opposed fuel cells 33. By arranging a plurality of cells, the current collecting characteristics between the fuel cells 33 can be improved.

The plate-shaped current collecting member 43 is arranged between the oxygen-side electrode 33c and the interconnector 33d, which is a flat portion of the fuel cell 33 facing each other, and the fuel cell 33 are connected in series. . Since the contact portion 43b of the plate-shaped current collecting member 43 is in contact with the flat portion, the contact portion 43b surely contacts and the electrical connection can be reliably performed.

Further, the portion of the contact portion 43b that protrudes toward the fuel cell unit has the fuel cell unit 3 with Ag paste interposed.
It is joined to 3. This Ag paste is baked at the time of power generation, and the contact portion 43b is joined to the interconnector 33d of the fuel cell 33 and the oxygen side electrode 33c, thereby electrically connecting the plate-shaped current collecting member 43 and the fuel cell 33. You can make enough connections.

FIG. 3C shows the contact portion 4 of the plate-shaped current collecting member 44.
4b is formed by interspersing a plurality of convex portions 44b1,
Similar effects can be obtained even with such a plate-shaped current collecting member 44.

The entire surfaces of the contact portions 43b and 44b are in contact with the interconnector 33d, and the oxygen side electrode 33c has the oxygen side electrode 33 of the contact portions 43b and 44b as described above.
You may make the part which protrudes to the c side contact. In this case, the connection and fixation of the contact portions 43b and 44b can be performed more reliably. It is also possible to form a plurality of slits in the contact portion and supply the fuel gas to the oxygen side electrode from this portion.

A plurality of these plate-shaped current collecting members 43, 44 are interposed between the fuel cells 33 facing each other, and these plate-shaped current collecting members 43, 44 are conductive Cr, F.
The surface of ferritic stainless steel whose main component is e is Ag
Is coated with an oxidation resistant material. still,
The plate-shaped current collecting members 43 and 44 are not limited to those described above as long as they have a conductive metal or alloy as a main component and the surface thereof is coated with an oxidation resistant substance.

As shown in FIG. 1, a fuel gas tank 45 for supplying the fuel gas to the fuel cell 33 is provided below the cell stack 35. The fuel gas tank 45 is supplied with fuel gas from the outside. A fuel gas supply pipe 51 for supplying to the fuel gas tank 45 is connected.

In the fuel gas tank 45, the fuel cell 3
3, a mounting jig 53 mounted on the lower end of the fuel cell 3 is screwed, so that the fuel cell 33 can be attached to the fuel gas tank 4
5 are set up respectively. That is, the attachment jig 53 is connected to the cell end side attachment jig 53a attached to the end portion of the fuel cell 33, and the both ends are screwed to the cell end side attachment jig 53a and the fuel gas tank 45, respectively. Member 53b
And threaded portions having opposite directions are formed at both ends of the connecting member 53b. When the connecting member 53b is rotated to one side, both ends are attached to the cell end side attachment jig 53a and the fuel gas tank. It is formed so as to be screwed to each of 45.

Cell end side attachment jig 53a, connecting member 53
In b, a through hole is formed so as to communicate with the fuel gas tank 45 and the fuel gas passage hole 34 of the fuel cell 33.

Further, as shown in FIG. 1, the oxygen-containing gas supply pipe 39, which is inserted through the combustion chamber 37, has its tip located between the fuel cells 33. The oxygen-containing gas supplied from the oxygen-containing gas supply pipe 39 is jetted toward the fuel gas tank 45 side and then flows to the heat exchange section 41 side. Therefore, the excess oxygen-containing gas that is not used in power generation flows between the fuel cells 33 and above the fuel cells 33, and the excess fuel gas that is not used in power generation is the fuel of the fuel cells 33. The gas is blown from above the fuel cell 33 through the gas passage hole 34, and the fuel gas and the oxygen-containing gas react and burn near the upper end of the fuel cell 22.

The heat exchange section 41 is composed of a heat exchanger 41a and an oxygen-containing gas storage chamber 41b provided facing the cell stack 35 with the combustion chamber 37 interposed therebetween.

As shown in FIG. 4, the heat exchanger 41a has a plate fin type structure in which flat plates 61 and corrugated plates 63 are alternately laminated, and a wave forming a passage communicating with the oxygen-containing gas storage chamber 41b is formed. The plate 63a is formed as shown in FIG. 4 (b), and the corrugated plate 63b forming a passage for discharging the combustion gas is formed as shown in FIG. 4 (c).

The combustion gas is introduced from the lower side surface of the heat exchanger 41a as shown by the one-dot chain line in FIG.
1a, while the oxygen-containing gas is introduced from the upper side surface of the heat exchanger 41a as shown by the broken line in FIG. 1 and guided to the lower side of the heat exchanger 41a, and the oxygen-containing gas storage chamber 41b. Will be introduced in.

As shown in FIG. 5, the oxygen-containing gas storage chamber 41b is provided at the end surface of the heat exchanger 41a on the side where the oxygen-containing gas is introduced, that is, the cell stack side end surface, and each of the corrugated plates 63a is provided. The oxygen-containing gas that has passed through the passage is once stored.

One end of a plurality of oxygen-containing gas supply pipes 39 are open and communicate with the oxygen-containing gas storage chamber 41b.

Further, as shown in FIG. 1, between the side surface of the oxygen-containing gas storage chamber 41b and the heat insulating material 31b, that is, around the oxygen-containing gas storage chamber 41b, the combustion gas in the combustion chamber 37 is heat-exchanged. It is used as a combustion gas introduction port 71 that is introduced into the vessel 41a. The combustion gas is led out to the passage of the corrugated plate 63b of the heat exchanger 41a via the combustion gas inlet 71.

In the fuel cell configured as described above, an oxygen-containing gas (for example, air) from the outside is introduced into the heat exchanger 41a through the oxygen-containing gas pipe 73 and then into the oxygen-containing gas storage chamber 41b. Then, the fuel gas (for example, hydrogen) is supplied into the fuel gas passage hole 34 of the fuel cell 33 through the fuel gas supply pipe 51 while being ejected between the fuel cell 33 through the oxygen-containing gas supply pipe 39. Generate electricity.

Excess fuel gas not used for power generation is jetted into the combustion chamber 37 from the upper end of the fuel gas passage hole 34,
Excess oxygen-containing gas that was not used for power generation is in the combustion chamber 3
7, the excess fuel gas and the excess oxygen-containing gas are reacted and burned to generate combustion gas, and this combustion gas is led out to the heat exchanger 41a via the combustion gas inlet 71 to perform heat exchange. It is discharged from the upper end of the container 41a.

In the fuel cell of the present invention, the plate-shaped current collecting members 43 and 44 have a spring property, and the abutting portions 43b and 44b.
Is in surface contact with the outer surface of the fuel cell 33, the contact area with the fuel cell 33 is larger than that of the conventional felt-shaped current collecting member, and the current collecting characteristics can be improved. Further, since the plate-shaped current collecting members 43 and 44 are plate-shaped, they have a large elastic force, and even if vibration or the like occurs, sufficient contact with the fuel cell unit 33 can be secured for a long time. In particular, the contact portion 43b,
Since the fuel gas passes between the plate-shaped current collecting members 43, 44 and the outer surface of the fuel cell 33 by forming the unevenness on the 44b, the fuel gas can be sufficiently supplied to the solid electrolyte 33b and the power generation characteristics can be improved. .

Further, since the plate-shaped current collecting member 43 is plate-shaped, it is more difficult to sinter than the conventional felt-shaped current collecting member even when the temperature inside the storage container 31 is high, and the fuel cell unit It is possible to secure sufficient contact with 33 for a long time. Further, since the current collecting member 43 is plate-shaped, when the plate-shaped current collecting member 43 is interposed between the interconnector 33d of the one fuel battery cell 33 and the oxygen side electrode 33c of the other fuel battery cell 33. Also, it is possible to reliably prevent conduction between the oxygen-side electrodes 33c of the one fuel battery cell 33 and the other fuel battery cell 33.

Excess fuel gas and oxygen-containing gas that have not contributed to power generation are introduced into the combustion chamber 37, and react and burn in the combustion chamber 37, and the combustion gas and the external oxygen-containing gas are removed. This heat exchanger 4 is introduced into the heat exchanger 41a.
The heat can be exchanged between the combustion gas and the oxygen-containing gas in 1a, and the oxygen-containing gas can be preheated at the time of start-up. Further, the oxygen-containing gas supply pipe 39 is inserted through the combustion chamber 37, so that the oxygen is generated by the combustion gas. Since the oxygen-containing gas in the containing-gas supply pipe 39 can be further heated, the startup time until the fuel cell 33 is indirectly heated by the heated oxygen-containing gas to substantially generate power can be shortened.

Further, since the combustion chamber 37, the oxygen-containing gas storage chamber 41b, and the heat exchanger 41a are formed adjacent to each other on the upper part of the cell stack 35, the high-temperature combustion gas burned in the combustion chamber 37 is supplied to a pipe or the like. Without heat exchanger 41a
It can be introduced directly into the chamber, and the preheating efficiency of oxygen-containing gas can be increased with a simple structure.

Further, since the combustion gas and the oxygen-containing gas can be heat-exchanged in the storage container 31, it is not necessary to separately provide a burner for preheating the oxygen-containing gas, and the size can be reduced. Moreover, the combustion gas can be effectively used.

Further, since the heat exchanger 41a is provided with the oxygen-containing gas storage chamber 41b, the heat exchanger 41a and the oxygen-containing gas supply pipe 39 can be connected via the oxygen-containing gas storage chamber 41b. The oxygen-containing gas from the heat exchanger 41a can be reliably supplied into the power generation chamber 49.

The present invention is not limited to the above-described embodiment, but various modifications can be made without departing from the spirit of the invention. For example, in the above-described embodiment, the fuel cell 33 having a flat shape and a plurality of fuel gas passage holes 34 as shown in FIG. 2 has been described, but the fuel cell has only one fuel gas passage hole. The shape of the fuel cell is not particularly limited.

Further, although the plate fin type is used as the heat exchanger 41a, the present invention is not limited to this, and it goes without saying that other heat exchangers may be used.

Furthermore, in the above-mentioned example, the example in which the fuel cells 33 are connected in series has been described, but it goes without saying that they may be connected in parallel. Further, although the fuel side electrode 33a is the inner electrode, the oxygen side electrode may be the inner electrode.

Further, the case where the fuel gas is supplied to the fuel cells by using one fuel gas tank 45 has been described, but in the present invention, the fuel gas tank is provided for each cell row, and the fuel cell is provided between them. A burner for direct heating may be provided. In this case, the fuel cell can be directly heated by the burner at the time of start-up, and the start-up can be performed quickly.

[0057]

In the cell stack of the present invention, the plate-shaped current collecting member is Z-shaped, and both ends of the plate-shaped current collecting member are in contact with the opposite outer surfaces of the fuel cell, respectively. Since it has a surface contact with the outer surface of the fuel cell, it is possible to improve the current collecting characteristics, and since the current collecting member is plate-shaped, the elastic force is large, and sufficient contact with the fuel cell can be ensured for a long time. Since the current collecting member is plate-shaped, it is difficult to sinter, and it is possible to secure sufficient contact with the fuel cell for a long time,
Further, since the current collecting member is plate-shaped, it does not accidentally conduct electricity to a place to be insulated during manufacturing.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a fuel cell of the present invention.

FIG. 2 is a cross-sectional view showing the cell stack of FIG.

3A and 3B show a state in which fuel cells are connected using a plate-shaped current collecting member. FIG. 3A is a perspective view, FIG. 3B is a plan view of FIG. 3A, and FIG. It is a perspective view which shows the plate-shaped current collection member which formed the convex part in scattered.

4A and 4B are views for explaining the concept of the heat exchanger of FIG. 1, in which FIG. 4A is a perspective view of the heat exchanger, and FIG. 4B is a corrugated plate for forming a passage for an oxygen-containing gas. FIG. 3C is a perspective view showing a corrugated plate for forming a passage for combustion gas.

FIG. 5 is a perspective view for explaining a heat exchange section of the present invention.

[Explanation of symbols]

31 ... Storage container 33 ... Fuel cell 33a ... Fuel side electrode (inner electrode) 33b ... Solid electrolyte 33c ... Oxygen side electrode (outer electrode) 33d ... Interconnector 34 ... Gas passage hole 43, 44 ... Plate-shaped current collecting member 43b, 44b ... Abutting part (both ends) 43b1 ... Recessed portion of contact portion

Claims (9)

[Claims] 1. A plate-shaped current collecting member is arranged between each of a plurality of arranged fuel cells to electrically connect the fuel cells facing each other, and the plate-shaped current collecting member is a gas. A cell stack having a Z-shape when viewed from the flow direction, and having both ends abutting against the outer surfaces of the facing fuel cells, respectively. 2. The cell stack according to claim 1, wherein the fuel cells have a flat shape, and the outer surfaces of the opposing fuel cells are substantially flat. 3. The unevenness is formed in the contact portion of the plate-shaped current collecting member with the outer surface of the fuel cell unit.
Or the cell stack according to 2. 4. A corrugated unevenness is formed at a contact portion of the plate-shaped current collecting member with the outer surface of the fuel cell, and a concave portion formed at the contact portion of the plate-shaped current collecting member has a gas flow direction. The cell stack according to any one of claims 1 to 3, wherein the cell stack is formed in a. 5. A plurality of plate-shaped current collecting members are arranged between fuel cell units facing each other.
The cell stack according to any one of the above. 6. A fuel cell, wherein a solid electrolyte and an outer electrode are sequentially formed on the surface of an inner electrode having a gas passage hole formed in the axial direction, and the solid electrolyte and the outer electrode are not formed on the inner side. An interconnector is formed on the surface of the electrode, and both ends of the plate-shaped current collecting member are in contact with the interconnector of one fuel battery cell and the outer electrode of the other fuel battery cell. Item 6. The cell stack according to any one of items 1 to 5. 7. The fuel cell has an outer electrode exposed to an oxygen-containing gas, and the plate-shaped current collecting member covers the surface of a conductive metal or alloy with an oxidation resistant substance. The cell stack according to any one of claims 1 to 6, which is configured. 8. The cell stack according to claim 1, wherein both ends of the plate-shaped current collecting member are bonded to the outer surfaces of the opposing fuel cells by a conductive paste. . 9. A fuel cell in which the cell stack according to any one of claims 1 to 8 is housed in a housing container.