JP2004228050A - Cell stack and fuel battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell stack and a fuel battery capable of improving current collector properties between fuel battery cells. <P>SOLUTION: On a cell stack 35, gas is made to flow through fuel battery cells 33, and a spiral current collector member 43, made of conductive member, electrically connecting the opposite fuel battery cells 33 to each other, is arranged between the fuel battery cells 33. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL 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 having a plurality of fuel cells having good current collection characteristics.
[0002]
[Prior art]
In recent years, various fuel cells in which a plurality of fuel cells are stored in a storage container have been proposed as next-generation energy.
[0003]
A conventional solid oxide fuel cell has a structure in which a plurality of fuel cells are housed in a housing, and the fuel cells are electrically connected in series or in parallel by a current collecting member. Oxygen-containing gas and fuel gas have been supplied to the cell, and have been performed at a high temperature of about 600 to 1000 ° C.
[0004]
As a current collecting member for making electrical connection between 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 in an array, for example, between an interconnector of one fuel cell and an outer electrode of the other fuel cell. A fuel cell is packed in series with a felt-shaped current collecting member to form a cell stack, and the cell stack is stored in a storage container (see Patent Document 1).
[0005]
[Patent Document 1]
JP 2000-058088 A
[Problems to be solved by the invention]
However, in the above-described fuel cell, since the felt-shaped current collecting member is formed of a fibrous metal, the interconnector of one fuel cell and the outer electrode of the other fuel cell are in point contact, There was a problem that the current collecting characteristics were still low.
[0007]
Also, even if the current collecting member is packed between the fuel cells, the contact with the fuel cell is not sufficiently performed due to vibration or a decrease in the elasticity of the current collecting member, and the current collecting characteristics are somewhat good at the beginning of power generation. However, the current collecting characteristics may deteriorate over time.
[0008]
Furthermore, when power is generated by introducing an oxygen-containing gas such as air between the fuel cells, oxidation proceeds from the surface of the fibrous metal, thereby deteriorating the current collection characteristics and reducing the elastic force of the metal felt. There is also a problem that the current collection characteristics decrease over time.
[0009]
Further, when the current collecting member is packed between the interconnector of one fuel cell and the outer electrode of the other fuel cell, one of the fuel cells is There is also a danger that the outer electrodes of the other fuel cells will conduct.
[0010]
An object of the present invention is to provide a cell stack and a fuel cell that can improve current collection characteristics between fuel cells.
[0011]
[Means for Solving the Problems]
The cell stack of the present invention is a cell stack in which gas flows between fuel cells, wherein a spiral current collecting member formed by spirally winding a linear member is arranged between the fuel cells, and is opposed to each other. The fuel cells are electrically connected to each other.
[0012]
The cross section of the line of such a spiral current collecting member may be a circle or an ellipse, and may be, for example, a quadrangle. The cross section of the line is desirably elliptical so that the contact area with the cell can be increased.
[0013]
In such a cell stack, the current collecting member has a spiral shape, and both ends of the current collecting member are in contact with the outer surfaces of the fuel cells facing each other. For example, as described above, the cross section of the line of the spiral current collecting member For example, when the shape is elliptical, the area in contact with the outer surface of the fuel cell unit and the area in contact with the fuel cell unit becomes larger than that of a conventional felt-shaped current collecting member, so that the current collecting characteristics can be improved.
[0014]
Further, since the spiral current collecting member has a spring property in the direction between the fuel cells and in the spiral traveling direction, the elastic force is large, and even if vibration or the like occurs, sufficient contact with the fuel cell can be ensured for a long time. Furthermore, since the spiral current collecting member has a larger wire diameter than the felt current collecting member, even when the temperature inside the storage container becomes high, the spiral current collecting member is less likely to be sintered than the conventional felt current collecting member. Sufficient contact with the fuel cell can be ensured for a long time without losing elasticity.
[0015]
Further, the cell stack of the present invention is characterized in that the spiral current collecting member has a drum shape when viewed from the spiral traveling direction, and a substantially flat portion of the spiral current collecting member is in contact with the fuel cell. . By forming the spiral current collecting member into a drum shape and forming the bent portion between substantially flat portions of the spiral current collecting member in this manner, even if the distance between the fuel cells is reduced, the spiral current collecting member becomes smaller. Since the width of the electric member does not increase, it is possible to prevent the electric member from being in contact with another fuel cell and being electrically short-circuited.
[0016]
Further, the cell stack of the present invention is characterized in that the spiral current collecting member is spirally formed in the gas flowing direction. In this way, by matching the gas flow direction and the spiral traveling direction of the current collecting member, a space through which gas can flow is formed inside the spiral of the spiral current collecting member disposed between the fuel cells, Gas supply to the fuel cell unit can be facilitated.
[0017]
Further, the cell stack of the present invention is characterized in that irregularities are formed at a contact portion of the spiral current collector with the outer surface of the fuel cell. In such a cell stack, the contact portion of the spiral current collecting member having the unevenness abuts on the outer surface of the opposed fuel cell, but the spiral current collecting member is formed on the outer surface of the fuel cell. The convex portion of the abutting portion abuts, and a space is formed between the outer surface of the fuel cell and the convex portion of the abutting portion, and the gas passes through this space. By increasing the supply to the electrode surface, the amount of gas supplied to the solid electrolyte via the porous outer electrode can be increased, and the power generation performance can be improved.
[0018]
Further, in the cell stack of the present invention, corrugated unevenness is formed in a contact portion of the spiral current collecting member with the outer surface of the fuel cell, and a concave portion formed in the contact portion of the spiral current collecting member is formed. It is characterized in that it is formed in the gas flow direction. In this case, the gas passes between the concave portion formed in the contact portion of the spiral current collector and the outer surface of the outer electrode, so that the supply of gas to the outer electrode surface can be increased, and the power generation performance can be improved.
[0019]
Further, in the cell stack of the present invention, the fuel cell includes an inner electrode, a solid electrolyte, and an outer electrode sequentially formed on the surface of the support having the gas flow path formed in the axial direction, and the solid electrolyte and the outer electrode are formed. An interconnector is provided on a support or an electrode on which no electrode is formed, and a spiral current collecting member is in contact with the interconnector of one fuel cell and the outer electrode of the other fuel cell. I do. Thus, it is suitably used when the fuel cells are electrically connected in series.
[0020]
Further, in the cell stack of the present invention, the fuel cell has the outer electrode exposed to the oxygen-containing gas, and the spiral current collecting member has a conductive metal or alloy formed on the surface of the oxidation-resistant substance. It is characterized by being constituted by being coated with. Since the spiral current collecting member has oxidation resistance, even if the spiral current collecting member is exposed to an oxygen-containing gas, it can have good electric conductivity.
[0021]
Furthermore, the cell stack of the present invention is characterized in that the contact portion of the spiral current collector with the outer surface of the fuel cell is joined to the outer surface of the fuel cell opposed by a conductive paste. Thereby, electrical connection between the spiral current collector and the fuel cell unit can be reliably performed. For example, when unevenness is formed at both ends of the spiral current collecting member, the projecting portion is joined to the outer surface of the fuel cell by the conductive paste.
[0022]
Further, in the cell stack of the present invention, the fuel cells are flat, and the outer surfaces of the opposed fuel cells are substantially flat. As described above, when the outer surfaces of the opposed fuel cells are substantially flat, the spiral current collecting member surely comes into contact with the flat portion of the outer surface of the fuel cells, so that the current collecting characteristics can be improved.
[0023]
The fuel cell of the present invention is characterized in that the above-described cell stack is stored in a storage container. In such a fuel cell, since the cell stack has good current collecting characteristics, excellent power generation characteristics can be exhibited.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an embodiment of the fuel cell of the present invention, and reference numeral 31 denotes a storage container having a heat insulating structure. Inside the storage container 31, a cell stack 35 in which a plurality of fuel cells 33 are assembled, a combustion space 37 formed above the cell stack 35, and an oxygen-containing gas supply pipe 39 passing through the combustion space 37. And a heat exchange section 41 provided above the combustion space 37.
[0025]
The storage container 31 includes a frame 31a made of a heat-resistant metal and a heat insulating material 31b provided on an inner surface of the frame 31a. A fuel gas tank 45 for supplying fuel gas to the fuel cell 33 is provided below the cell stack 35. The fuel gas tank 45 is provided with a fuel gas supply for supplying fuel gas to the fuel gas tank 45 from outside. Tube 51 is connected.
[0026]
An attachment jig 53 attached to the lower end of the fuel cell 33 is screwed to the fuel gas tank 45, whereby the fuel cells 33 stand on the fuel gas tank 45, respectively. That is, the attachment jig 53 is connected to the cell end side attachment jig 53 a attached to the end of the fuel cell 33 and both ends are screwed to the cell end side attachment jig 53 a and the fuel gas tank 45, respectively. The connecting member 53b is formed with screw portions having opposite directions at both ends, and when the connecting member 53b is rotated to one side, the both ends are connected to the cell end side mounting jig 53a and The fuel gas tanks 45 are formed so as to be screwed respectively.
[0027]
A through hole is formed in the cell end side mounting jig 53 a and the connecting member 53 b so as to communicate with the fuel gas tank 45 and the fuel gas flow path of the fuel cell 33.
[0028]
The oxygen-containing gas supply pipe 39 passing through the combustion space 37 has a tip located between the fuel cells 33. The oxygen-containing gas supplied from the oxygen-containing gas supply pipe 39 is ejected toward the fuel gas tank 45, and then flows toward the heat exchange unit 41. Therefore, the excess oxygen-containing gas not used in the power generation flows above the fuel cells 33 between the fuel cells 33, and the excess fuel gas not used in the power generation is The fuel gas is blown from above the fuel cell 33 through the gas flow path, and the fuel gas and the oxygen-containing gas react and burn near the upper end of the fuel cell 33.
[0029]
The heat exchange section 41 includes a heat exchanger 41a and an oxygen-containing gas storage chamber 41b provided to face the cell stack 35 via the combustion space 37.
[0030]
The heat exchanger 41a has, for example, a plate fin structure. The combustion gas is introduced from the lower side surface of the heat exchanger 41a as shown by a dashed line and discharged above the heat exchanger 41a, while the oxygen-containing gas is subjected to heat exchange as shown by a broken line in FIG. It is introduced from the upper side surface of the vessel 41a, is guided below the heat exchanger 41a, and is introduced into the oxygen-containing gas storage chamber 41b.
[0031]
The oxygen-containing gas storage chamber 41b is provided on the end face of the heat exchanger 41a on the cell stack 35 side, and temporarily stores the oxygen-containing gas that has passed through the heat exchanger 41a. One end of a plurality of oxygen-containing gas supply pipes 39 is open and communicates with the oxygen-containing gas storage chamber 41b.
[0032]
Further, 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, a combustion gas inlet 71 for introducing the combustion gas in the combustion space 37 to the heat exchanger 41a is provided. Have been. The combustion gas is led out to the heat exchanger 41a via the combustion gas inlet 71.
[0033]
As shown in FIG. 2, the cell stack 35 in the storage container 31 is configured by arranging the fuel cells 33 in three rows, and the electrodes of the two outermost fuel cells 33 adjacent to each other are connected to each other. The plurality of fuel cells 33 arranged in three rows are electrically connected in series by being connected by the conductive member 42. Note that FIG. 1 shows four columns.
[0034]
As shown in FIG. 2, the fuel cell 33 of the present invention has a flat cross section, a plate shape or an elliptic column shape as a whole, and a plurality of fuel gas flow paths 34 formed therein. Have been.
[0035]
The fuel cell 33 has a flat cross section, and has a plate-like or elliptic columnar porous support 33a as a whole, and a porous fuel-side electrode 33b, a dense solid electrolyte 33c, An oxygen-side electrode 33d made of porous conductive ceramics is sequentially laminated, and an interconnector 33e is formed on an outer surface of a support 33a opposite to the oxygen-side electrode 33d.
[0036]
That is, the fuel cell 33 has a cross-sectional shape including arc-shaped portions provided at both ends in the width direction and a pair of flat portions connecting these arc-shaped portions, and the pair of flat portions is flat, They are formed almost in parallel. An interconnector 33e is formed on one of the pair of flat portions, and a fuel-side electrode 33b, a solid electrolyte 33c, and an oxygen-side electrode 33d are sequentially formed on the other flat portion.
[0037]
In the cell stack of the present invention, the spiral current collecting member 43 is disposed between the one fuel cell 33 and the other fuel cell 33, and the fuel electrode 33b of the one fuel cell 33 is supported. It is electrically connected to an oxygen-side electrode 33d of the other fuel cell 33 via an interconnector 33e provided on the body 33a and a spiral current collecting member 43.
[0038]
The spiral current collecting member 43 has a circular shape when viewed from the gas flow direction, and is formed in a spiral shape when viewed from the gas flow direction as shown in FIGS. Are located. The cross section of the linear conductive member forming the spiral current collecting member 43 is circular, elliptical, or angular. In particular, in order to increase the contact area with the fuel cell 33, the cross section is elliptical, or A square shape is desirable.
[0039]
As shown in FIGS. 3A and 3B, such a spiral current collecting member 43 has, for example, an elliptical shape when viewed in the spiral traveling direction. The ellipse is formed by a substantially flat surface 43a that comes into contact with the fuel cells 33, and a non-contact portion 43b that maintains electrical and physical connections between the fuel cells 33.
[0040]
Since such a spiral current collecting member 43 has elasticity in the direction between the fuel cells 33 and in the axial direction of the fuel cells 33, a change in the distance between the fuel cells 33 due to a temperature change, It is possible to flexibly follow a change in the length of the fuel cell 33 in the axial direction, and the electrical connection between the fuel cells 33 can be maintained even when a heat cycle accompanying power generation and stop is repeated. For the same reason, disconnection due to vibration or the like does not occur.
[0041]
The spiral current collecting member 43 has a circular shape when viewed from the spiral traveling direction. However, even when the distance between the fuel cells 33 is reduced, the spiral current collecting member 43 is deformed to form a spiral current collecting member 43 that is adjacent to the spiral current collecting member 43. Since there is no risk of contact with the current collecting member 43 and no risk of contact with other fuel cells 33, the spiral traveling direction of the spiral current collecting member 43 as shown in FIGS. It is desirable that the shape as seen from is a drum shape.
[0042]
The drum-shaped spiral current collecting member 43 is formed on a substantially flat surface 43a that comes into contact with the fuel cell 33 and a non-contact portion 43b that keeps electrical and physical connection between the fuel cells 33. The bent portion 43c is formed.
[0043]
The bent portion 43c generates elasticity in the direction between the fuel cells 33, and when the distance between the fuel cells 33 is reduced, the bent portion 43c moves inside the spiral current collecting member 43. There is no interference or contact with the adjacent spiral current collecting member 43 or the adjacent fuel cell 33, and the reliability of the electrical connection can be improved.
[0044]
As shown in FIG. 4, the contact portion 43a of the spiral current collecting member 43 has corrugated unevenness, and a concave portion 43a1 formed in the contact portion 43a is formed in the gas flow direction. In FIG. 4, the direction perpendicular to the paper surface is the gas flow direction. The gas passes between the concave portion 43a1 formed in the contact portion 43a of the spiral current collecting member 43 and the outer surface of the oxygen-side electrode 33d, and the supply of the oxygen-containing gas to the surface of the oxygen-side electrode 33d can be increased. Performance can be improved.
[0045]
A plurality of spiral current collecting members 43 are arranged between the opposed fuel cells 33. By arranging a plurality of fuel cells, the current collection resistance between the fuel cells 33 can be reduced, and the current collection characteristics between the fuel cells 33 can be improved.
[0046]
Further, the spiral current collecting member 43 is disposed between the interconnector 33e which is a flat portion of the opposed fuel cell 33 and the oxygen-side electrode 33d, and the fuel cells 33 are connected in series. Since the contact portion 43a of the spiral current collecting member 43 is in contact with the flat portion of the fuel cell 33, the contact can be reliably made and the electrical connection can be reliably made.
[0047]
A portion of the contact portion 43a protruding toward the fuel cell 33 is joined to the oxygen-side electrode 33d and the interconnector 33e of the fuel cell 33 via a conductive paste 44, for example, an Ag paste. This Ag paste is baked, for example, at the time of power generation, and the contact portion 43a is joined to the interconnector 33e and the oxygen-side electrode 33d of the fuel cell 33, whereby the spiral current collector 43 and the fuel cell 33 are connected. A sufficient electrical connection can be obtained.
[0048]
Note that the entire surface of the contact portion 43a contacts the interconnector 33e, and the portion of the contact portion 43a protruding toward the oxygen electrode 33d may be contacted with the oxygen electrode 33d as described above. In this case, the connection and fixing of the contact portion 43a can be performed more reliably.
[0049]
A plurality of these spiral current collecting members 43 are interposed between the opposed fuel cells 33, and these spiral current collecting members 43 are made of a ferritic stainless steel mainly composed of conductive Cr and Fe. The surface is coated with an oxidation-resistant substance made of Ag. Note that the spiral current collecting member 43 is not limited to the above as long as it has a conductive metal or alloy as a main component and its surface is coated with an oxidation-resistant substance.
[0050]
In the fuel cell of the present invention, the spiral current collecting member 43 has a spring property, for example, because the abutting portion 43a having an elliptical cross section or an angular contact is in surface contact with the outer surface of the fuel cell 33. The area in contact 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, the spiral current collecting member 43 has a large elastic force, and can secure a sufficient contact with the fuel cell 33 for a long period even if vibration or the like occurs. Further, in particular, by forming irregularities in the contact portion 43a and passing the fuel gas between the spiral current collecting member 43 and the outer surface of the fuel cell 33, the fuel gas can be sufficiently supplied to the solid electrolyte 33b, Power generation characteristics can be improved.
[0051]
Further, since the spiral current collecting member 43 is linear, even when the temperature inside the storage container 31 becomes high, the spiral current collecting member 43 is less likely to sinter than the conventional felt-shaped current collecting member. Sufficient contact can be secured for a long time.
[0052]
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 via the oxygen-containing gas pipe 73, and is introduced into the oxygen-containing gas storage chamber 41b. A fuel gas (for example, hydrogen) is supplied to the fuel gas flow path of the fuel cell 33 via the fuel gas supply pipe 51 while causing the fuel gas to be ejected between the fuel cells 33 via the content gas supply pipe 39 to generate electric power.
[0053]
Excess fuel gas not used for power generation gushes into the combustion space 37 from the upper end of the fuel gas flow path, and excess oxygen-containing gas not used for power generation flows into the combustion space 37, and surplus fuel gas and The excess oxygen-containing gas is reacted and burned to generate combustion gas, which is led out to the heat exchanger 41a via the combustion gas inlet 71 and discharged from the upper end of the heat exchanger 41a.
[0054]
Excess fuel gas and oxygen-containing gas that have not contributed to power generation are introduced into the combustion space 37, react and burn in the combustion space 37, and the combustion gas and external oxygen-containing gas are exchanged by the heat exchanger. The heat is exchanged between the combustion gas and the oxygen-containing gas by the heat exchanger 41a, so that the oxygen-containing gas can be preheated at the time of start-up. The insertion allows the oxygen-containing gas in the oxygen-containing gas supply pipe 39 to be further heated by the combustion gas, so that the fuel cell 33 is indirectly heated by the heated oxygen-containing gas to substantially generate power. Start-up time can be reduced.
[0055]
Furthermore, since the combustion space 37, the oxygen-containing gas storage chamber 41b, and the heat exchanger 41a are formed adjacent to each other at the upper part of the cell stack 35, the high-temperature combustion gas burned in the combustion space 37 can be piped. The preheating efficiency of the oxygen-containing gas can be increased with a simple structure.
[0056]
Further, since the combustion gas and the oxygen-containing gas can be heat-exchanged in the storage container 31, there is no need to separately provide a burner for preheating the oxygen-containing gas in the storage container 31, and the combustion gas can be reduced in size. Can be used effectively.
[0057]
Further, since the oxygen-containing gas storage chamber 41b is provided in the heat exchanger 41a, the connection between the heat exchanger 41a and the oxygen-containing gas supply pipe 39 can be performed through the oxygen-containing gas storage chamber 41b. The oxygen-containing gas from 41a can be reliably supplied into the power generation space 75.
[0058]
Note that the present invention is not limited to the above-described embodiment, and various changes can be made without changing the gist of the present invention. For example, in the above embodiment, the description has been given using the fuel cell 33 having a plurality of flat fuel gas channels 34 as shown in FIG. 2. However, the fuel cell 33 has one fuel gas channel 34. The shape of the fuel cell 33 is not particularly limited.
[0059]
In some cases, a plurality of spiral current collecting members 43 are arranged between the fuel cells 33. In this case, for example, the spiral current collecting members 43 are combined to form, for example, a raft shape. Thus, the spiral current collecting member 43 can be easily arranged.
[0060]
Further, in the above example, the example in which the fuel cells 33 are connected in series has been described. However, the fuel cell using the wide spiral current collecting member 43 in which a plurality of such spiral current collecting members 43 are combined is used. Assembling becomes easier by connecting a plurality of cells 33 in parallel.
[0061]
Further, although the fuel-side electrode 33b is an inner electrode, the oxygen-side electrode 33d may be an inner electrode.
[0062]
Further, the case where the fuel gas is supplied to the fuel cells 33 using one fuel gas tank 45 has been described. However, in the present invention, the fuel gas tanks 45 are provided for each row of the fuel cells 33, and the fuel cell A burner for directly heating the cell 33 may be provided. In this case, the fuel cell 33 can be directly heated by the burner at the time of startup, and the startup can be performed more quickly.
[0063]
【The invention's effect】
In the cell stack of the present invention, the current collecting member has a spiral shape, and is in contact with the outer surface of the opposed fuel cell. Since the spiral current collecting member has spring properties, the current collecting member is in surface contact with the outer surface of the fuel cell. In addition to being able to improve the current collecting characteristics, the spiral shape of the current collecting member has a large elastic force, and can ensure sufficient contact with the fuel cell for a long period of time. And sufficient contact with the fuel cells can be ensured for a long period of time.
[Brief description of the 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 spiral current collecting member and a shape of the spiral current collecting member. FIG. 3A is a side view of the spiral current collecting member viewed from the side. (B) is a plan view of the spiral current collecting member used in (a) as viewed from the gas flow direction, (c) is a side view of another type of spiral current collecting member viewed from the side, and (d) is a side view thereof. It is the top view which looked at the spiral current collection member used at (c) from the gas flow direction.
FIG. 4 is an explanatory diagram showing a connection structure between a fuel cell and a spiral current collector.
[Explanation of symbols]
31 ... storage container 33 ... fuel cell 33a ... support 33b ... fuel side electrode (inside electrode)
33c: solid electrolyte 33d: oxygen side electrode (outer electrode)
33e Interconnector 34 Gas flow path 35 Cell stack 43 Spiral current collecting member 43a Contact portions (both ends)
43a1... Recess of the contact portion

Claims (10)

A cell stack in which gas flows between fuel cells, wherein a spiral current collecting member formed by spirally winding a linear member is disposed between the fuel cells, and the opposing fuel cells are separated from each other. A cell stack characterized by being electrically connected. 2. The cell stack according to claim 1, wherein the spiral current collecting member has a drum shape when viewed from the spiral traveling direction, and a substantially flat portion of the spiral current collecting member is in contact with the fuel cell. 3. The cell stack according to claim 1, wherein the spiral current collecting member is spirally formed in the gas flowing direction. The cell stack according to any one of claims 1 to 3, wherein an uneven portion is formed at a contact portion of the spiral current collector with the outer surface of the fuel cell. Corrugations are formed at the contact portion of the spiral current collecting member with the outer surface of the fuel cell, and the concave portion formed at the contact portion of the spiral current collecting member is formed in the gas flow direction. The cell stack according to any one of claims 1 to 4, wherein: The fuel cell has a structure in which an inner electrode, a solid electrolyte, and an outer electrode are sequentially formed on the surface of a support having a gas flow path formed in the axial direction, and the solid electrolyte and the outer electrode are not formed on the support or The spiral current collector is in contact with the interconnector of one fuel cell and the outer electrode of the other fuel cell. The cell stack described in Crab. The fuel cell has an outer electrode exposed to an oxygen-containing gas, and the spiral current collector is configured by coating a conductive metal or alloy surface with an oxidation-resistant substance. The cell stack according to claim 1, wherein: The abutting portion of the spiral current collector with the outer surface of the fuel cell is joined to the outer surface of the opposed fuel cell by a conductive paste, according to any one of the preceding claims. Cell stack. 9. The cell stack according to claim 1, wherein the fuel cells have a flat shape, and the outer surfaces of the opposed fuel cells are substantially flat. A fuel cell comprising the cell stack according to any one of claims 1 to 9 stored in a storage container.

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