JP2011134448A - Solid electrolyte fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell capable of preventing deformation of an air electrode collector or a fuel electrode collector. <P>SOLUTION: In the solid electrolyte fuel cell 10, a first separator 17 laminated on a fuel electrode collector 16, and supplying fuel gas to a membrane electrode assembly 12 is provided with a plurality of projections 25, a plurality of through-holes 26 each capable of insertion-coupling with the projection of the first separator are provided on the fuel electrode collector intervened between the first separator and the membrane electrode assembly, a second separator 22 laminated on an air electrode collector 21, and supplying air to the membrane electrode assembly is provided with a plurality of projections 32, and a plurality of through-holes 33 each capable of insertion-coupling with the projection of the second separator are provided on the air electrode collector intervened between the second separator and the membrane electrode assembly. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides a solid oxide fuel that supplies fuel gas to a membrane electrode assembly through an anode current collector and generates electric power by supplying air to the membrane electrode assembly through an air electrode collector It relates to batteries.

  In a solid oxide fuel cell, an air electrode (cathode) and a fuel electrode (anode) are stacked on both sides of a solid electrolyte to form a membrane electrode assembly (MEA), and an air electrode current collector on both sides of the membrane electrode assembly. (Cathode current collector) and a fuel electrode current collector (anode current collector) are stacked, and a separator is stacked on each of the air electrode current collector and the fuel electrode current collector to form a single cell.

According to this single cell, air (oxygen) is supplied from the separator on the air electrode current collector side to the air electrode current collector, and fuel gas (hydrogen or the like) is supplied from the separator of the fuel electrode current collector to the fuel electrode current collector. ) Is supplied.
The air supplied to the air electrode current collector reaches the air electrode side through the pores of the air electrode current collector.
On the other hand, the fuel gas supplied to the anode current collector reaches the anode side through the pores of the anode current collector.

The oxygen that has reached the air electrode side reaches the vicinity of the interface with the solid electrolyte via the pores in the air electrode, and the fuel gas that has reached the fuel electrode side near the interface with the solid electrolyte via the pores in the fuel electrode. To reach.
Air (oxygen) that reaches the vicinity of the interface with the air electrode receives electrons from the air electrode and is ionized into oxide ions. The oxide ions reach the vicinity of the interface with the fuel electrode by diffusing and moving in the solid electrolyte toward the fuel electrode.

  Oxide ions that have reached the vicinity of the interface with the fuel electrode react with the fuel gas in the vicinity of this interface to emit electrons, and the electrons are taken out from the single cell as electromotive force to generate electric power (for example, (See Patent Document 1).

JP 2002-280026 A

Here, since the electric power generated from the single cell is relatively small, it is necessary to stack a plurality of single cells in order to obtain a desired electric power.
In addition, the plurality of single cells are stacked with a load applied in order to reduce electrical resistance between the plurality of single cells and to prevent diffusion of air and fuel gas.

On the other hand, in order to allow the air supplied to the air electrode current collector to reach the air electrode side, a plurality of (many) pores through which air passes are formed in the entire area of the air electrode current collector.
Further, in order to allow the fuel gas supplied to the fuel electrode current collector to reach the fuel electrode side, a plurality of (many) pores through which the fuel gas passes are formed throughout the fuel electrode current collector.
That is, the air electrode current collector and the fuel electrode current collector are formed of members that are allowed to deform to some extent with respect to the load.

On the other hand, as described above, the solid oxide fuel cell is stacked in a state where a load is applied to a plurality of single cells.
For this reason, it is conceivable that the air electrode current collector and the fuel electrode current collector are deformed with time due to heat generated when generating power in the solid oxide fuel cell (crushing occurs).
As described above, the air electrode current collector and the fuel electrode current collector are deformed, so that it becomes difficult to maintain a desired load on a plurality of single cells.

  An object of the present invention is to provide a solid oxide fuel cell capable of preventing the air electrode current collector and the fuel electrode current collector from being deformed.

  According to the first aspect of the present invention, fuel gas is supplied to the membrane electrode assembly through the fuel electrode current collector, and electric power is generated by supplying air to the membrane electrode assembly through the air electrode current collector. In the solid oxide fuel cell, a protrusion is provided on a first separator that is stacked on the fuel electrode current collector and supplies the fuel gas to the membrane electrode assembly, and is provided between the first separator and the membrane electrode assembly. A through hole into which the protruding portion of the first separator can be fitted is provided in the interposed fuel electrode current collector, and is stacked on the air electrode current collector to supply the air to the membrane electrode assembly. Protrusions are provided on two separators, and through holes into which the protrusions of the second separator can be fitted are provided in the air electrode current collector interposed between the second separator and the membrane electrode assembly. Features.

  The invention according to claim 2 is characterized in that the fuel electrode current collector and the air electrode current collector are formed of a foam made of a conductive metal or a mesh member made of a conductive metal.

In the invention which concerns on Claim 1, the protrusion was provided in the 1st separator and the through-hole was provided in the anode current collector so that the protrusion of the 1st separator can fit.
Further, a protrusion is provided on the second separator, and a through hole is provided in the air electrode current collector so that the protrusion of the second separator can be fitted.

Therefore, the protrusion of the first separator can be fitted into the through hole of the fuel electrode current collector, and the protrusion of the second separator can be fitted into the through hole of the air electrode current collector.
Further, with the load applied to the plurality of stacked single cells, the protrusion of the first separator is brought into contact with the membrane electrode assembly, and the protrusion of the second separator is brought into contact with the membrane electrode assembly. (Contact).

As a result, the load applied to the plurality of single cells can be received by the protrusions provided on the first and second separators, and the load acts on the fuel electrode current collector and the air electrode current collector. Can be prevented.
By preventing the load from acting on the fuel electrode current collector and the air electrode current collector, it is possible to prevent the fuel electrode current collector and the air electrode current collector from being deformed (crushed).

Therefore, the electrical resistance between the single cells can be kept small, and a decrease in the conductivity due to an increase in contact resistance can be prevented.
In addition, the occurrence of a gap between the single cells can be suppressed, and the diffusion of air and fuel gas from the gap between the single cells can be prevented.
As a result, the electrical resistance between the single cells can be suppressed to a low level, and air and fuel gas can be prevented from diffusing between the single cells, so that the power generation efficiency of the solid oxide fuel cell can be increased.

Furthermore, by preventing the fuel electrode current collector and the air electrode current collector from being deformed (crushed) by a load, a gap is generated between the membrane electrode assembly and the fuel electrode current collector, It is possible to prevent a gap from being generated between the electrode assembly and the air electrode current collector.
Therefore, both surfaces of the membrane electrode assembly can be covered with the fuel electrode current collector or the air electrode current collector.

In the invention according to claim 2, the fuel electrode current collector and the air electrode current collector are formed of a foam or a mesh member.
That is, as described above, the load is applied to the fuel electrode current collector and the air electrode current collector by receiving the load applied to the plurality of single cells by the protrusions provided on the first and second separators. Can be prevented.

Therefore, it is not necessary to increase the strength (rigidity) of the fuel electrode current collector and the air electrode current collector more than necessary.
As a result, the fuel electrode current collector and the air electrode current collector can be easily formed of a foam or mesh member that does not need to be relatively rigid, and the cost of the fuel electrode current collector and the air electrode current collector can be reduced. Can be suppressed.

1 is a cross-sectional view showing a solid oxide fuel cell according to the present invention. It is sectional drawing shown in the state which decomposed | disassembled the single cell of FIG. 3A is a cross-sectional view taken along line 3a-3a in FIG. 2, and FIG. 3B is a cross-sectional view taken along line 3b-3b in FIG. It is a figure explaining the example which supports a load with protrusion of the 1st and 2nd separator concerning the present invention. It is a figure explaining the example which generate | occur | produces electric power with the solid oxide fuel cell which concerns on this invention.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

A solid oxide fuel cell 10 according to an embodiment will be described.
As shown in FIG. 1, the solid oxide fuel cell 10 is configured such that desired power can be obtained by stacking a plurality of single cells 11 with a load F1 applied.

  The single cell 11 includes a membrane electrode assembly (MEA) 12 and a fuel electrode current collector (anode current collector) laminated on a lower surface (lower surface of a fuel electrode 14 described later) 14a of the membrane electrode assembly (MEA) 12. 16, the first separator 17 stacked on the lower surface 16 a of the fuel electrode current collector 16, and the air electrode current collector (cathode) stacked on the upper surface (upper surface of the air electrode 15 described later) 15 a of the membrane electrode assembly 12. Current collector) 21 and a second separator 22 stacked on the upper surface 21 a of the air electrode current collector 21.

  The membrane electrode assembly 12 includes a solid electrolyte 13, a fuel electrode (anode) 14 stacked on the lower surface 13 a of the solid electrolyte 13, and an air electrode (cathode) 15 stacked on the upper surface 13 b of the solid electrolyte 13. Yes.

As shown in FIGS. 2 and 3, the first separator 17 is provided with a fuel gas supply channel 24 for supplying a fuel gas (such as hydrogen) to the anode current collector 16. The supply port 24a is provided in the center 17a.
The first separator 17 is provided with a plurality of protrusions 25 on a surface 17 b facing the anode current collector 16.
As an example, the plurality of protrusions 25 of the first separator 17 are formed by embossing.

The fuel electrode current collector 16 is formed of a foam made of a conductive metal or a mesh member made of a conductive metal, so that the fuel gas supplied from the supply port 24a of the fuel gas supply channel 24 is converted into a membrane electrode. A plurality of pores (not shown) led to the fuel electrode 14 of the joined body 12 are provided.
A foam is a member having a plurality of (many) pores in a continuous solid material.
The mesh member is a member having a plurality of (many) pores by knitting a wire in a mesh shape.
The fuel electrode current collector 16 is formed with a plurality of through holes 26 so as to penetrate from the lower surface 16 a facing the first separator 17 to the upper surface 16 b facing the fuel electrode 14.

In a state where the first separator 17 is stacked on the fuel electrode current collector 16, a plurality of protrusions 25 are fitted into the plurality of through holes 26, and the tips 25 a of the plurality of protrusions 25 are the fuel electrodes 14 of the membrane electrode assembly 12. (See FIG. 1).
Therefore, in a state where the plurality of single cells 11 are stacked with the load F 1, the load F 1 acting on the first separator 17 is transmitted to the fuel electrode 14 through the plurality of protrusions 25, and the load is applied to the fuel electrode current collector 16. F1 can be prevented from acting.

Thereby, it is not necessary to increase the strength (rigidity) of the fuel electrode current collector 16 more than necessary.
Therefore, the fuel electrode current collector 16 can be easily formed of a foam or mesh member that does not require relatively rigidity, and the cost of the fuel electrode current collector 16 can be reduced.

The second separator 22 is provided with an air supply channel 31 for supplying air (oxygen) to the air electrode current collector 21, and a supply port 31a of the air supply channel 31 is provided in the center 22a. .
The second separator 22 is provided with a plurality of protrusions 32 on a surface 22 b facing the air electrode current collector 21.
The plurality of protrusions 32 of the second separator 22 are formed by embossing as an example, similarly to the plurality of protrusions 25 of the first separator 17.

The air electrode current collector 21 is formed of a foam made of a conductive metal or a mesh member made of a conductive metal, so that air supplied from the supply port 31a of the air supply flow path 31 is converted into a membrane electrode assembly. A plurality of pores (not shown) leading to 12 air electrodes 15 are provided.
A foam is a member having a plurality of (many) pores in a continuous solid material.
The mesh member is a member having a plurality of (many) pores by knitting a wire in a mesh shape.
The air electrode current collector 21 has a plurality of through holes 33 so as to penetrate from the upper surface 21 a facing the second separator 22 to the lower surface 21 b facing the air electrode 15.

In the state where the second separator 22 is stacked on the air electrode current collector 21, the plurality of protrusions 32 are fitted into the plurality of through holes 33, and the tips 32 a of the plurality of protrusions 32 are the air electrodes 15 of the membrane electrode assembly 12. (See FIG. 1).
Therefore, in a state where the plurality of single cells 11 are stacked with the load F1, the load F1 acting on the second separator 22 is transmitted to the air electrode 15 through the plurality of protrusions 32, and the load is applied to the air electrode current collector 21. F1 can be prevented from acting.

Thereby, it is not necessary to increase the strength (rigidity) of the air electrode current collector 21 more than necessary.
Therefore, the air electrode current collector 21 can be easily formed of a foam or a mesh member that does not need to consider relatively rigidity, and the cost of the air electrode current collector 21 can be suppressed.

Next, an example in which the load F1 is supported by the protrusions 25 and 32 of the first and second separators 17 and 22 will be described with reference to FIG.
As shown in FIG. 4, in the state where the first separator 17 is laminated on the fuel electrode current collector 16, the tips 25 a of the plurality of protrusions 25 abut against the fuel electrode 14 of the membrane electrode assembly 12.
Similarly, in a state where the second separator 22 is stacked on the air electrode current collector 21, the tips 32 a of the plurality of protrusions 32 come into contact with the air electrode 15 of the membrane electrode assembly 12.

Therefore, in a state where the plurality of single cells 11 are stacked with the load F <b> 1, the load F <b> 1 acting on the first separator 17 is transmitted to the fuel electrode 14 via the plurality of protrusions 32.
Thereby, it is possible to prevent the load F1 from acting on the fuel electrode current collector 16.
Similarly, in a state where the plurality of single cells 11 are stacked with the load F 1, the load F 1 acting on the second separator 22 is transmitted to the air electrode 15 via the plurality of protrusions 32.
Therefore, it is possible to prevent the load F1 from acting on the air electrode current collector 21.

Next, an example of generating electric power by supplying fuel gas (hydrogen or the like) or air (oxygen) to the solid oxide fuel cell 10 will be described with reference to FIG.
As shown in FIG. 5, fuel gas (such as hydrogen) is supplied to the anode current collector 16 from the supply port 24 a of the fuel gas supply channel 24 of the first separator 17 as indicated by an arrow A.
Further, air (oxygen) is supplied to the air electrode current collector 21 from the supply port 31 a of the air supply flow path 31 of the second separator 22 as indicated by an arrow B.

  The fuel gas supplied to the anode current collector 16 reaches the anode 14 as indicated by an arrow C through the pores of the anode current collector 16. The fuel gas that has reached the fuel electrode 14 reaches the vicinity of the interface 32 between the fuel electrode 14 and the solid electrolyte 13 through pores in the fuel electrode 14.

  On the other hand, the air supplied to the air electrode current collector 21 reaches the air electrode 15 as indicated by an arrow D through the pores of the air electrode current collector 21. The air that has reached the air electrode 15 side passes through the pores in the air electrode 15 and reaches the vicinity of the interface 31 between the air electrode 15 and the solid electrolyte 13.

Air (oxygen) that reaches the vicinity of the interface 31 between the air electrode 15 and the solid electrolyte 13 receives electrons from the air electrode 15 and is ionized into oxide ions. The oxide ions diffuse and move in the solid electrolyte 13 toward the fuel electrode 14.
The oxide ions that have reached the vicinity of the interface 32 between the fuel electrode 14 and the solid electrolyte 13 react with the fuel gas in the vicinity of the interface 32 to emit electrons, and the electrons are taken out as electromotive force to generate electric power. .

Here, in the conventional solid oxide fuel cell, the load F1 acting on the first separator 17 is transmitted to the anode current collector 16, and the load F1 acting on the second separator 22 is applied to the air electrode current collector 21. It is transmitted.
Thus, when the load F1 acts on the anode current collector 16 and the air electrode current collector 21, the heat generated when the fuel electrode current collector 16 and the air electrode current collector 21 generate electric power over time. It is conceivable that the material is deformed (crushed).

On the other hand, as shown in FIG. 4, in the solid oxide fuel cell 10, the load F <b> 1 acting on the first separator 17 is transmitted as the load F <b> 2 to the fuel electrode 14 through the plurality of protrusions 25. It is possible to prevent the load F1 from acting on the electric body 16.
Similarly, the load F1 acting on the second separator 22 is transmitted as the load F2 to the air electrode 15 through the plurality of protrusions 32, and the load F1 can be prevented from acting on the air electrode current collector 21.

Therefore, it is possible to prevent the fuel electrode current collector 16 and the air electrode current collector 21 from being deformed over time (caused to be crushed) by the load F1.
Thereby, the electrical resistance between the single cells 11 can be suppressed to a low level, and a decrease in electrical conductivity due to an increase in contact resistance can be prevented.
In addition, the generation of a gap between the single cells 11 can be suppressed, and the diffusion of air and fuel gas from the gap between the single cells 11 can be prevented.

  Thus, while suppressing the electrical resistance between the single cells 11 and preventing the air and the fuel gas from diffusing from between the single cells 11, the power generation efficiency of the solid oxide fuel cell 10 can be increased.

Further, a gap is generated between the membrane electrode assembly 12 and the fuel electrode current collector 16 by preventing the fuel electrode current collector 16 and the air electrode current collector 21 from being deformed (crushed) by the load F1. It is possible to prevent the gap between the membrane electrode assembly 12 and the air electrode current collector 21 from being generated.
Therefore, the upper surface 15 a of the membrane electrode assembly 12 (that is, the upper surface of the air electrode 15) 15 a can be covered with the air electrode current collector 21.
Similarly, the lower surface 14 a of the membrane electrode assembly 12 (that is, the lower surface of the fuel electrode 14) 14 a can be covered with the fuel electrode current collector 16.

The solid oxide fuel cell 10 according to the present invention is not limited to the above-described embodiments, and can be changed or improved as appropriate.
For example, in the above-described embodiment, the example in which the protrusions 25 and 32 of the first and second separators 17 and 22 are formed by embossing is described. However, the present invention is not limited to this, and other methods may be used. It is.

  In addition, the solid oxide fuel cell 10, the single cell 11, the membrane electrode assembly 12, the fuel electrode current collector 16, the first separator 17, the air electrode current collector 21, the second separator 22, and the protrusions shown in the above embodiment. The shapes and configurations of 25 and 32 and the through holes 26 and 33 are not limited to those illustrated, and can be changed as appropriate.

  The present invention is suitable for application to a solid oxide fuel cell in which electric power is generated by supplying fuel gas to a membrane electrode assembly through an anode current collector and supplying air through an air electrode current collector. is there.

  DESCRIPTION OF SYMBOLS 10 ... Solid electrolyte type fuel cell, 11 ... Single cell, 12 ... Membrane electrode assembly, 16 ... Fuel electrode current collector, 17 ... First separator, 21 ... Air electrode current collector, 22 ... Second separator, 25, 32 ... protrusions, 26, 33 ... through holes.

Claims (2)

In a solid electrolyte fuel cell that generates fuel by supplying fuel gas to a membrane electrode assembly through an anode current collector and supplying air to the membrane electrode assembly through an air electrode current collector,
Protruding to the first separator that is laminated on the fuel electrode current collector and supplies the fuel gas to the membrane electrode assembly,
The fuel electrode current collector interposed between the first separator and the membrane electrode assembly is provided with a through hole into which a protrusion of the first separator can be fitted,
Protruding to the second separator that is stacked on the air electrode current collector and supplies the air to the membrane electrode assembly,
A solid oxide fuel cell, wherein a through-hole into which a protrusion of the second separator can be fitted is provided in the air electrode current collector interposed between the second separator and the membrane electrode assembly. .   2. The solid oxide fuel cell according to claim 1, wherein the fuel electrode current collector and the air electrode current collector are formed of a foam made of a conductive metal or a mesh member made of a conductive metal. .

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