JP2002329508A - Solid electrolyte fuel cell and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell and its manufacturing method providing miniaturization and reducing internal resistance by providing electrodes (an air electrode and a fuel electrode) and a solid electrolyte as thin films. SOLUTION: In an SOFC, single cells comprised by holding electrode reaction parts 10-12 and 14 between porous metal substrates 1 and 2 and laminating an electrically conductive and gas impermeable substrate 13 are continuously connected, the electrode reaction parts are comprised by covering side faces of the air electrode 10, the solid electrolyte 12 and the fuel electrode 11 by an electrically insulating and gas impermeable substrate 14, the porous metal substrates 1 and 2 communicate gas, and a cell output is collected by the electrode reaction parts. The SOFC is comprised by continuously connecting single cells comprised by laminating the electrode reaction parts so that the porous metal substrates are held between the electrodes and laminating a porous metal substrate B. The SOFC is comprised by arranging a single cell component comprised by inscribing a porous metal substrate A in the electrode reaction parts in an insertion hole of the porous metal substrate B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid oxide fuel cell (SOFC) which uses a solid electrolyte to obtain electric energy by an electrochemical reaction, and more particularly to a solid electrolyte comprising a solid electrolyte sandwiched between electrodes. The present invention relates to an electrolyte fuel cell and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a structure in which a solid oxide electrolyte is sandwiched between two electrodes, that is, a fuel electrode (anode) and an air electrode (cathode), has been used as a power generating element, and hydrocarbons such as hydrogen and methane are provided on the fuel electrode side. 2. Description of the Related Art A solid oxide fuel cell (hereinafter abbreviated as “SOFC”) that generates power through a system fuel gas and an oxidizing gas such as oxygen or air on the air electrode side is known. Such a SOFC has high power generation efficiency and can also utilize waste heat, and is expected as a third-generation fuel cell.

As a cell structure of a conventionally known SOFC, an electrolyte supporting type cell can be exemplified. This cell is formed by sintering an electrolyte material powder at a high density to form a dense electrolyte body, and forming a fuel electrode and an air electrode on the front and back by screen printing or the like. In addition, this cell uses an electrolyte as a support member for a power generation element. Further, as another cell structure, an electrode supporting type cell can be exemplified. This cell is obtained by sintering an electrode material powder to form a porous electrode body, and forming an electrolyte layer and an electrode layer thereon by screen printing or the like. Further, this cell uses a porous electrode body as a support member of a power generation element.

[0004] Specifically, Japanese Patent Application Laid-Open No. 9-50812 reports a porous electrode substrate made of a sintered body of ceramic electrode material powder having a porosity that varies in the thickness direction.
Japanese Patent Application Laid-Open No. 2000-200614 similarly reports a porous electrode substrate made of a sintered body of ceramic electrode material powder. Further, as a support member for the fuel electrode / electrolyte / air electrode (hereinafter abbreviated as "power generation element"), a cell in which the fuel electrode / electrolyte / air electrode is formed on a porous metal substrate by a thermal spraying method has been reported. Furthermore, the DLR cell (Pl
asma Sprayed Thin-Film SOF
C for Reduced Operating T
emperature, Fuel Cells Bu
lletin, pp597-600, 2000).

As disclosed in Japanese Patent Application Laid-Open Nos. 7-45297 and 63-106063, conventionally known SOFCs collect electric power generated at a fuel electrode and an air electrode. Ni is separated from the electrode to
Current collectors such as felt are used. Further, such an SOFC is used by electrically connecting a large number of battery elements in series or in parallel. At this time, a member (hereinafter, referred to as “IC (interconnector)”) electrically connects each battery element. ) "). This I. C. May have a current collector function. Furthermore, the SOFC generates a hydrocarbon fuel gas, such as hydrogen or methane, on the fuel electrode side and an oxidizing gas, such as oxygen or air, on the air electrode side, thereby generating a gas flow for guiding the gas to the electrode surface. Requires a member to form a path. This gas flow path is I. C. It may have functions.

[0006]

However, since the above-mentioned electrolyte-supporting cell uses the electrolyte as a support member of the power generation element, the thickness of the electrolyte is about several hundreds μm to several mm due to mechanical strength requirements. The internal resistance of the part sometimes increased. In addition, since the electrode-supporting cell uses the electrode as a support member of the power generation element, the thickness of the electrode body is approximately several mm or more due to mechanical strength requirements, and in addition to the increase in internal resistance of the electrode portion, In some cases, the permeability and diffusion of the fuel gas or the oxidizing gas were deteriorated. Further, Japanese Patent Application Laid-Open No. 9-5081 with improved air permeability
The porous ceramic electrode substrates disclosed in JP-A-2000-200614 and JP-A-2000-200614 are not sufficient for electric conduction and have brittleness inherent to ceramic materials. Furthermore, I.I. C. In addition, the gas flow path member must be provided separately from the electrolyte-supported cell and the electrode-supported cell, which has been an obstacle to downsizing the SOFC.

In the cell obtained by using the above-mentioned thermal spraying method, the thickness of each of the electrodes and the electrolyte is as large as several tens of μm, and the internal resistance is not reduced, probably due to the restriction of the thermal spray film formation. Because the surface is rough, the electrode and electrolyte cannot be thinned and the internal resistance cannot be reduced.As a gas flow path to the lower fuel electrode of the cell, the porous metal body is not used as a gas flow path and has a substantially concave cross section. Because the plate is used, the cell size cannot be reduced. As the gas flow path to the upper air electrode of the cell, the porous metal body is not used as the gas flow path, and the plate 15 having a roughly wavy section is used. As a result, the cell size cannot be reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to reduce the internal resistance by thinning the electrodes (air electrode and fuel electrode) and the solid electrolyte. It is another object of the present invention to provide a solid oxide fuel cell that achieves miniaturization and a method for manufacturing the same.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a porous metal substrate having a desired strength is used as a support substrate for a power generation element, and that the output of a battery is collected. It has been found that the above-mentioned problems can be solved by making the electric function and the gas flow path function fulfill, and the present invention has been completed.

That is, the solid oxide fuel cell of the present invention
A single cell in which an electrically conductive and gas-impermeable substrate is laminated on the front or back surface of a sandwich formed by sandwiching both surfaces of an electrode reaction portion between porous metal substrates A and B, in a direction substantially the same as the lamination direction A solid electrolyte fuel cell formed by connecting a plurality of air electrodes, a solid electrolyte, and a fuel electrode in this order. The porous metal substrates A and B are covered with a permeable substrate, and flow fuel gas or oxidizing gas and collect battery output from the electrode reaction section.

Further, in another solid oxide fuel cell according to the present invention, an electrode reaction section is laminated on both surfaces of the porous metal substrate A so that the porous metal substrate A is sandwiched between air electrodes or fuel electrodes. A solid electrolyte fuel cell comprising a plurality of unit cells each formed by laminating a porous metal substrate B on any one of the electrode reaction sections in a direction substantially the same as the lamination direction; The reaction section is formed by covering the side surface of a laminate obtained by laminating an air electrode, a solid electrolyte, and a fuel electrode in this order with an electrically insulating and gas impermeable substrate, and the porous metal substrates A and B are provided. In addition, a fuel gas or an oxidizing gas is circulated, and the battery output is collected from the electrode reaction section.

Further, in still another solid oxide fuel cell according to the present invention, a plurality of single-cell components formed by inscribing a porous metal substrate A to an annular electrode reaction portion are provided on a porous metal substrate B. A solid oxide fuel cell having a plurality of insertion holes, wherein the electrode reaction part electrically insulates a side surface of a stacked body obtained by stacking an air electrode, a solid electrolyte, and a fuel electrode in this order. -It is characterized by being covered with a gas impermeable substrate, wherein the porous metal substrates A and B flow fuel gas or oxidizing gas and collect battery output from the electrode reaction section.

Further, in the method for manufacturing a solid oxide fuel cell according to the present invention, in manufacturing the solid oxide fuel cell, (a) laminating an air electrode or a fuel electrode on a porous metal substrate A; b) stacking a solid electrolyte on the air electrode or fuel electrode, (c) stacking a fuel electrode or air electrode on the solid electrolyte, and (d) stacking a porous metal substrate B on the fuel electrode or air electrode. (E) laminating an electrically conductive and gas impermeable substrate on the porous metal substrate B;
Alternatively, an electrically insulating and gas-impermeable substrate is coated on the side surface of the laminate formed by the fuel electrode and the solid electrolyte, and (g) a single layer obtained in the laminating steps (a) to (e) and the covering step (f). It is characterized in that a plurality of cell structures are continuously joined in substantially the same direction as the lamination direction and joined.

Further, another method of manufacturing a solid oxide fuel cell according to the present invention comprises the steps of: (a) stacking an air electrode or a fuel electrode on both surfaces of a porous metal substrate A to manufacture the solid oxide fuel cell; (B) laminating a solid electrolyte on the air electrode or fuel electrode, and (c) coating an electrical insulating / gas impermeable substrate on a side surface of the laminate formed by the air electrode or fuel electrode and the solid electrolyte; (D) a fuel electrode or an air electrode is laminated on both surfaces of the porous metal substrate B, (e) an electrically insulating / gas impermeable substrate is coated on the side surfaces of the fuel electrode or the air electrode, and (f) a laminating step. (A) and (b) and the single-cell constituent part obtained in the coating step (c) and the single-cell constituent part obtained in the stacking step (d) and the coating step (e) are alternately arranged in substantially the same direction as the stacking direction. And joining them continuously.

Still another method of manufacturing a solid oxide fuel cell according to the present invention comprises the steps of: (a) forming an air electrode or fuel on the side surface of the porous metal substrate A in the longitudinal direction; (B) coating a solid electrolyte on the air electrode or fuel electrode, (c) coating a fuel electrode or air electrode on the solid electrolyte, and (d) inserting a plurality of pieces into the porous metal substrate B. (E) arranging a plurality of single cell constituent parts obtained in the coating steps (a) to (c) in the insertion hole, and (f) lengthening the air electrode, the fuel electrode and the solid electrolyte. It is characterized in that both ends in the direction are covered with an electrically insulating and gas impermeable substrate, and the inner wall of the insertion hole is joined to the fuel electrode or the air electrode.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a solid oxide fuel cell according to the present invention will be described in detail. In addition, in this specification, "%" shows a mass percentage unless otherwise specified. Also,
For convenience of explanation, one surface such as a base or an electrode is described as “front surface” and “upper surface”, and the other surface is described as “back surface” and “lower surface”, but these are equivalent elements and are replaced with each other. It goes without saying that the configuration is also included in the scope of the present invention.

As described above, the solid oxide fuel cell (hereinafter abbreviated as "SOFC") of the present invention has a structure in which both surfaces of the electrode reaction portion are sandwiched between the porous metal substrates A and B on the surface or the back surface thereof. A plurality of unit cells each formed by laminating an electrically conductive and gas impermeable substrate are connected in substantially the same direction as the laminating direction. Typically, as shown in FIG. 1, a single cell as a unit component (has a structure of porous metal substrate 1 / air electrode 10 / solid electrolyte 12 / fuel electrode 11 / porous metal substrate 2)
In series in the same direction as the stacking direction.

Here, as shown in FIG. 1, the electrode reaction section includes an air electrode 10, a solid electrolyte 12, and a fuel electrode 11.
Are laminated in this order, and the side surfaces of the laminate are covered with an electrically insulating and gas impermeable substrate. in this way,
By covering the side surface of the electrode reaction part with an insulating member, the air electrode 10 and the fuel electrode 11 and the porous metal bases 1 and 2 are reliably insulated and the integration of cells is facilitated. In addition, as the above-mentioned electrically insulating and gas-impermeable substrate, glass, ceramics, a metal whose surface is coated with glass or ceramics, and any combination thereof can be used. Furthermore, such electrical insulation
The gas impermeable substrate is preferably coated with a thickness of 0.02 to 10 mm. If the thickness is less than 0.02 mm, it may not be possible to secure and maintain sufficient insulation including reliability. If the thickness exceeds 10 mm, not only the cell itself becomes large, but also the reliability is reduced due to cracks and chips. In some cases, the insulation cannot be maintained.

Further, since the electrically conductive and gas impermeable base is provided between each battery element (air electrode, solid electrolyte and fuel electrode), each battery element can be connected in series in the film thickness direction. As the electrically conductive and gas impermeable substrate, the same kind of metal material as the porous metal body can be used. Further, such an electrically conductive and gas impermeable substrate is
It is preferable to use with a thickness of 0.05 to 10 mm.
If the thickness is less than 0.05 mm, the strength as a joining member between cells is low, and good inter-cell connection may be hindered,
If it exceeds 10 mm, the cell itself becomes thicker, which may impair the reliability of the laminate.

Further, the porous metal substrates A and B are characterized in that the fuel gas or the oxidizing gas flows and the battery output is collected from the electrode reaction section. By using a porous metal having gas permeability and diffusibility as a support substrate, a fuel gas is attached to the fuel electrode 10 that is closely attached to the porous metal substrate 1 and is attached to the porous metal substrate 2. The air electrode 11 can be supplied with air. That is, since the porous metal base serves both as a support base and a gas flow path, all of the solid electrolyte, the air electrode, and the fuel electrode can be thinned to reduce the internal resistance. The porous metal substrate also has a role of supporting the battery element, and the SOFC can maintain a desired strength even when the battery element is thinned.

The porous metal substrates A and B desirably have electrical conductivity. In this case, the battery output is collected from the electrode reaction section. That is, since the porous metal substrate also functions as a current collecting member, the porous metal substrate of the present invention
FC can be miniaturized. Nickel (Ni), nickel chromium (Ni-
Cr), nickel chromium iron (Ni-Cr-Fe), nickel chromium tungsten molybdenum (Ni-Cr-W-
Mo), nickel cobalt (Ni-Co), nickel copper (Ni-Cu), silver (Ag), silver palladium (Ag-P
r), silver platinum (Ag-Pt), iron chromium nickel (Fe
-Cr-Ni) or iron-chromium aluminum (Fe-Cr-A)
It is preferred to use alloys comprising metals consisting of 1) and any combination thereof. Further, the porous metal substrate is typically used in the form of a foam having a desired porosity, but is not particularly limited thereto, and may be a sintered body of metal fibers having a desired pore, a metal fine particle. A sintered body, a metal mesh, or the like can be used. Further, a porous substrate obtained by plating ceramics with a metal (such as Ni and Ag) may be used. It should be noted that a metal material other than the above may not have sufficient resistance to a reducing atmosphere or an oxidizing atmosphere generated by a fuel gas or an oxidizing gas.
Further, in the present SOFC, a hydrocarbon-based gas such as methanol, natural gas, gasoline or the like can be used as a fuel gas, but at this time, the porous metal substrate provided on the fuel electrode side is not violated by sulfur contained in the fuel gas. You need to do that. Further, the present SOFC uses oxygen gas as an oxidizing gas,
Although air can be used, it is necessary to prevent the porous metal substrate provided on the air electrode side from being oxidized in the oxidizing gas.

Further, the porous metal substrates A and B are
The thickness is preferably 0.1 to 5 mm. In this case, the strength as a supporting member, I.P. C. Electric conductivity as an (interconnector) and gas permeability / diffusion as a gas flow path can be ensured. If the thickness of the porous metal substrate is less than 0.1 mm, the strength as a support member may be insufficient, or the electrical conductivity may be insufficient. May deteriorate.

Further, as the porous metal substrates A and B, a laminate formed by laminating two or more porous substrate layers of the same type or different types having different porosity can be used. The porous metal substrate can be closely attached to the entire surface of the fuel electrode or the air electrode, which is a thin-film battery element, so that the thin-film battery element can be favorably supported and good current collection can be performed. The constituent materials of the same or different kinds of porous base layers can be appropriately selected from the above-mentioned metal materials and the like.

Further, by using the porous metal substrate as described above, a thin film SOFC capable of collecting current in the film thickness direction can be obtained.
Can be formed. Thereby, the cell internal resistance in the film thickness direction can be reduced. Specifically, the air electrode and / or the fuel electrode coated with the porous metal substrate, in other words, the electrode of the air electrode and the fuel electrode which is in contact with the porous metal substrate is 5
The thickness can be set to ｍ100 μm. in this case,
The thickness is at least half that of the conventional electrode-supported cell.
This is effective because it can be reduced to 0 or less, and the internal electric resistance of the electrode portion can be simply reduced by about 1/20. Also,
The solid electrolyte may have a thickness of 50 μm or less. In this case, the thickness can be reduced to at least 1/20 or less as compared with the conventional electrolyte-supported cell, and the internal electric resistance of the electrolyte portion can be simply reduced by about 1/20, which is effective. In addition, such an electrode and a solid electrolyte are:
It can be coated by employing various film forming methods such as PVD, CVD, thermal spraying, screen printing, spray coating, plating, electrophoresis, and sol-gel method. Further, an electrode and / or a solid electrolyte can be formed by attaching a green sheet containing an electrode and a solid electrolyte material to the porous metal body and sintering the green sheet.

Next, another SOFC of the present invention will be described in detail. In such an SOFC, an electrode reaction part is laminated on both surfaces of the porous metal base A so that the porous metal base A is sandwiched between the air electrodes or the fuel electrodes, and a porous part is provided on one of the electrode reaction parts. A plurality of unit cells formed by laminating the metal bases B are connected in substantially the same direction as the laminating direction. With such an SOFC configuration, it is only necessary to pass a fuel gas or an oxidizing gas through the porous metal substrate A and the porous metal substrate B, which is effective because the fuel cell can be reduced in size and simplified. Typically, as shown in FIG. 2, the unit components (porous metal substrate 1 / fuel electrode 10 / solid electrolyte 12 / air electrode 11 / porous metal substrate 2 / air electrode 11 / solid electrolyte 12 / fuel electrode) 10) are connected in a direction substantially the same as the laminating direction.
OFC can be mentioned.

Here, the SOFC was connected in parallel without using an electrically conductive and gas impermeable substrate,
It has almost the same configuration as the series SOFC described above,
Specifically, they differ in the following points. That is, as the electrically insulating / gas impermeable substrate, glass, ceramics,
Alternatively, a metal whose surface is coated with glass or ceramics, or a material relating to any combination thereof can be used. Such an electrically insulating and gas impermeable substrate is preferably coated with a thickness of 0.02 to 10 mm. If the thickness is less than 0.02 mm, it may not be possible to secure and maintain a sufficient insulating property including reliability.
If it exceeds mm, not only the cell itself becomes large, but also the reliability is reduced due to cracks, chips, etc., and the insulating property may not be maintained. Further, the porous metal substrates A and B preferably have a thickness of 0.1 to 5 mm. In this case, the strength as a supporting member, I.P. C.
Electric conductivity as an (interconnector) and gas permeability / diffusion as a gas flow path can be ensured. If the thickness of the porous metal substrate is less than 0.1 mm, the strength as a support member may be insufficient, or the electrical conductivity may be insufficient. May deteriorate.

Next, still another SOFC of the present invention will be described in detail. Such a SOFC has a plurality of single-cell components formed by inscribing a porous metal substrate A to an annular electrode reaction portion, and is disposed in a plurality of insertion holes provided in the porous metal substrate B. Such an SOFC configuration is effective because gas sealing becomes easy (simple) and thermal shock resistance is improved. Typically, as shown in FIG. 3, a plurality of single-cell constituent portions (a configuration in which a fuel electrode 10, a solid electrolyte 12, and an air electrode 11 are coated on the outer periphery of a cylindrical porous metal substrate 1 in this order) is used. Is provided in a plurality of insertion holes provided in the porous metal substrate 2. In this SOFC, the porous metal substrate 2
By appropriately arranging an insulating member inside, it can be connected in series or in parallel. In addition, the shape of the insertion hole is round, square,
Oval and triangular shapes can be exemplified.

Here, the SOFC has substantially the same configuration as the above-mentioned serial type SOFC and parallel type SOFC except that the electrode reaction section is formed in a ring shape, but specifically differs in the following points. That is, the porous metal substrates A and B
Preferably has a thickness of 0.1 to 5 mm. In this case, strength as a support member, I.P. C. Electric conductivity as an (interconnector) and gas permeability / diffusion as a gas flow path can be ensured. If the thickness of the porous metal substrate is less than 0.1 mm, the strength as a supporting member may not be sufficient, and if it exceeds 5 mm, the cell and the stack may be large.

Next, the method for manufacturing an SOFC of the present invention will be described in detail. In this manufacturing method, (a) an air electrode or a fuel electrode is stacked on the porous metal substrate A, (b) a solid electrolyte is stacked on the air electrode or the fuel electrode, and (c) a fuel electrode is stacked on the solid electrolyte. Or (d) laminating a porous metal substrate B on the fuel electrode or the air electrode,
An electrically conductive and gas impermeable substrate is laminated on the porous metal substrate B, and (f) an electrically insulating and gas impermeable substrate is formed on the side surface of the laminate formed by the air electrode and / or the fuel electrode and the solid electrolyte. (H) coating the permeable substrate, joining (g) a plurality of the single cell structures obtained in the laminating steps (a) to (e) and the covering step (f) in a direction substantially the same as the laminating direction; The laminating steps (d) to (e) and the covering step (f) are performed, for example, at 850.
C. and 1 Pa, and (i) the bonding step (g)
For example, the above-described series SOFC is performed at 900 ° C. and 0.5 Pa. By employing this method, an SOFC in which the electrodes (the air electrode and the fuel electrode) and the solid electrolyte are thinned can be manufactured, which is effective. In addition, if it has a desired SOFC configuration, the above step (a)
The order of (i) to (i) is not particularly limited, and typically, a SOFC can be manufactured by a manufacturing process as shown in FIG. Since the electrically insulating and gas-impermeable substrate is finally coated on the side surfaces of the electrode and the solid electrolyte, the electrically insulating and gas-impermeable base is coated on the side surfaces of the air electrode or the fuel electrode and the solid electrolyte in the coating step (f). After coating the permeable / gas impermeable substrate, the laminating step (c) can be performed so that the side surface of the fuel electrode or the air electrode is coated with the electrically insulating / gas impermeable substrate. Further, the substrate, the electrode and the solid electrolyte are typically PVD,
The bonding can be performed by a CVD method, a screen printing method, a spray coating method, a plating method, an electrophoresis method, a sol-gel method, or the like. The electrode and the solid electrolyte are PVD
It can be coated by adopting various film forming methods such as a method, a CVD method, a thermal spraying method, a screen printing method, a spray coating method, a plating method, an electrophoresis method and a sol-gel method. Further, an electrode and / or a solid electrolyte can be formed by attaching a green sheet containing an electrode and a solid electrolyte material to the porous metal body and sintering the green sheet.

Next, another SOFC manufacturing method of the present invention will be described in detail. In this manufacturing method, (a) the air electrode or the fuel electrode is laminated on both surfaces of the porous metal substrate A,
(B) laminating a solid electrolyte on the air electrode or the fuel electrode,
(C) coating a side surface of the laminate formed by the air electrode or fuel electrode and the solid electrolyte with an electrically insulating and gas impermeable substrate,
(D) A fuel electrode or an air electrode is laminated on both surfaces of the porous metal substrate B, and (e) an electric insulating property is provided on the side surface of the fuel electrode or the air electrode.
A gas-impermeable substrate, and (f) a unit cell component obtained in the laminating steps (a) and (b) and the coating step (c);
A plurality of the unit cell constituent parts obtained in the laminating step (d) and the covering step (e) are alternately and continuously joined in substantially the same direction as the laminating direction, and joined (g) in the laminating steps (a), (b) and (D) and the coating step (c) are performed, for example, at 850 ° C. and 1 Pa, and (h) the coating step (e) and the joining step (f) are performed, for example, at 900 ° C. and 0.5 Pa. Thus, the above-mentioned parallel type SOFC is obtained. By employing this method, an SOFC in which the electrodes (the air electrode and the fuel electrode) and the solid electrolyte are thinned can be manufactured, which is effective. The order of the steps (a) to (h) is not particularly limited as long as the SOFC has a desired SOFC configuration. Typically, a parallel SOFC can be manufactured by the manufacturing steps shown in FIG. The substrate, the electrode, and the solid electrolyte can be typically joined by a PVD method, a CVD method, a screen printing method, a spray coating method, a plating method, an electrophoresis method, a sol-gel method, or the like. The electrode and the solid electrolyte can be coated by employing various film forming methods such as a PVD method, a CVD method, a thermal spraying method, a screen printing method, a spray coating method, a plating method, an electrophoresis method and a sol-gel method. Further, an electrode and / or a solid electrolyte can be formed by attaching a green sheet containing an electrode and a solid electrolyte material to the porous metal body and sintering the green sheet.

Next, still another method of manufacturing an SOFC of the present invention will be described in detail. In such a manufacturing method,
(A) an air electrode or a fuel electrode is coated on the side surface in the longitudinal direction of the porous metal substrate A; (b) a solid electrolyte is coated on the air electrode or the fuel electrode; and (c) a fuel electrode or a fuel electrode is coated on the solid electrolyte. Covering the air electrode, (d) providing a plurality of insertion holes in the porous metal substrate B, and (e) covering the insertion holes with the coating steps (a) to (c).
(F) coating the air electrode, the fuel electrode and the solid electrolyte on both ends in the longitudinal direction with an electrically insulating and gas-impermeable substrate; Steps (a) to (c) and (f) are performed, for example, under the conditions of 850 ° C. and atmospheric pressure, and the inner wall of the insertion hole and the fuel electrode or the air electrode are joined to obtain the above-mentioned tubular SOFC. . By adopting this method, the electrodes (air electrode and fuel electrode)
This is effective because an SOFC in which the solid electrolyte is thinned can be manufactured. The order of the steps (a) to (g) is not particularly limited as long as the SOFC has a desired SOFC configuration. Typically, a tubular SOFC can be manufactured by the manufacturing steps shown in FIG. The substrate, the electrode, and the solid electrolyte can be typically joined by a PVD method, a CVD method, a screen printing method, a spray coating method, a plating method, an electrophoresis method, a sol-gel method, or the like. Further, the insertion hole can be formed by, for example, drilling, electric discharge machining, laser processing, or the like, and typically a pore of about 1 to 5 mm can be the insertion hole.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 As shown in FIG. 4, a sintered body of fine metal particles (foamed metal of Ni-16Cr-8Fe) was used as a porous substrate 1 and an electrode 10 (Ni-8% YSZ),
The solid electrolyte 12 (8% YSZ) is laminated in this order by a screen printing method, the side surfaces of the electrode 10 and the solid electrolyte 12 are covered with an electrically insulating and gas-impermeable base 14, and the electrode 11 is provided on the upper surface of the solid electrolyte 12. (LSC) is laminated by a screen printing method, and a sintered metal fine particle (Ni-16C) is formed thereon.
r-8Fe foamed metal) as a porous substrate 2
Further, an electrically conductive / gas impermeable substrate 13 is laminated and SO
A single cell as an FC constituent unit was obtained. A plurality of the single cells were stacked in the same direction to obtain a series-type solid oxide fuel cell as shown in FIG. 900 ° C, 0.5 Pa between each layer
By heating and pressurizing. Table 1 shows the configurations of the porous substrate, the electrically insulating and gas impermeable substrate, the electrically conductive and gas impermeable substrate, and the battery elements (electrodes and solid electrolyte).

Example 2 Example 1 was performed except that the process shown in FIG. 5 was adopted and no electrically conductive and gas impermeable substrate was used.
By substantially the same operation as described above, a parallel solid oxide fuel cell as shown in FIG. 2 was obtained. In addition, a porous substrate,
Table 1 shows the configurations of the electrically insulating and gas impermeable substrate and the battery elements (electrodes and solid electrolyte).

(Example 3) A columnar SOF employing the process shown in FIG. 6 without using an electrically conductive and gas impermeable substrate
The same operation as in Example 1 was repeated, except that the C constituent unit was placed in the insertion hole of the porous metal substrate, to obtain a tube-type solid oxide fuel cell as shown in FIG. Table 1 shows the configurations of the porous substrate, the electrically insulating and gas impermeable substrate, and the battery elements (electrodes and solid electrolyte).

[0036]

[Table 1]

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to these, and various modifications can be made within the scope of the present invention. For example, the structural unit of the SOFC is not limited to a single cell, and a cell plate formed by two-dimensionally connecting and integrating a plurality of single cells in a direction substantially perpendicular to the stacking direction can be used as the structural unit. Further, a gas flow path may be provided inside the porous metal alone. Furthermore, the shape of the SOFC can be arbitrarily selected.
It can be manufactured according to the desired output. The arrangement of the fuel electrode and the air electrode can be switched according to the type of gas (hydrogen, air, etc.) flowing therethrough.

[0038]

As described above, according to the present invention, a porous metal substrate having a desired strength is used as a support substrate for a power generation element, and a battery output power collection function and a gas flow path function are provided. Electrodes (air electrode and fuel electrode)
Further, it is possible to provide a solid electrolyte fuel cell in which the solid electrolyte is thinned to reduce the internal resistance to achieve downsizing, and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of a series solid oxide fuel cell.

FIG. 2 is a configuration diagram illustrating an example of a parallel solid oxide fuel cell.

FIG. 3 is a cross-sectional view illustrating an example of a tube-type solid oxide fuel cell.

FIG. 4 is a schematic view illustrating an example of a manufacturing process of the series-type solid oxide fuel cell.

FIG. 5 is a schematic view showing one example of a manufacturing process of a parallel type solid oxide fuel cell.

FIG. 6 is a schematic view showing one example of a manufacturing process of a tubular solid oxide fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Porous metal base (A or B) 2 Porous metal base (B or A) 10 Electrode (fuel electrode or air electrode) 11 Electrode (air electrode or fuel electrode) 12 Solid electrolyte 13 Electric conductivity and gas impermeability Substrate 14 Electrically insulating and gas-impermeable substrate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 4/88 H01M 4/88 T 8/12 8/12 8/24 8/24 E (72) Inventor Nissan Motor Co., Ltd. (72) Inside the Nissan Motor Co., Ltd. (72) Inventor Mitsuru Yamanaka, Nissan Motor Co., Ltd. (72) Inventor Makoto Uchiyama Kanagawa-ku, Yokohama City, Kanagawa Prefecture 2 Takaracho Nissan Motor Co., Ltd. F-term (reference) 5H018 AA06 AS02 AS03 BB01 BB03 BB08 CC06 DD01 DD08 EE04 EE10 EE12 HH03 5H026 AA06 BB01 BB02 BB04 CC01 CV02 CV08 CX01 EE02 EE08 HH03

Claims (27)

[Claims] 1. A single cell comprising an electrically conductive and gas-impermeable substrate laminated on the front or back surface of a sandwiched body comprising both sides of an electrode reaction portion sandwiched between porous metal substrates A and B. A solid electrolyte fuel cell comprising a plurality of cells connected in substantially the same direction as the direction, wherein the electrode reaction unit electrically connects a side surface of a stacked body obtained by stacking an air electrode, a solid electrolyte, and a fuel electrode in this order. Insulation
A solid electrolyte type wherein the porous metal substrates A and B flow fuel gas or oxidizing gas and collect battery output from the electrode reaction section. Fuel cell. 2. The method according to claim 1, wherein the air electrode and / or the fuel electrode is 5-1.
2. The solid oxide fuel cell according to claim 1, wherein said fuel cell has a thickness of 00 [mu] m. 3. The solid oxide fuel cell according to claim 1, wherein said solid electrolyte has a thickness of 50 μm or less. 4. The method according to claim 1, wherein the porous metal substrate A and / or the porous metal substrate B have a thickness of 0.1 to 5 mm. Solid electrolyte fuel cell. 5. The method according to claim 1, wherein the electrically conductive and gas impermeable substrate comprises:
The solid oxide fuel cell according to any one of claims 1 to 4, wherein the thickness is 0.05 to 10 mm. 6. The electric insulating / gas impermeable substrate according to claim 1,
The solid oxide fuel cell according to any one of claims 1 to 5, which is coated with a thickness of 0.02 to 10 mm. 7. The method according to claim 7, wherein the porous metal substrate A and / or the porous metal substrate B is made of nickel, nickel chromium, nickel chromium iron, nickel chromium tungsten molybdenum,
7. An alloy containing at least one metal selected from the group consisting of nickel cobalt, nickel copper, silver, silver palladium, silver platinum, iron chromium nickel and iron chromium aluminum. A solid oxide fuel cell according to any one of the preceding claims. 8. The electric conductive and gas impermeable substrate according to claim 1,
Nickel, nickel chrome, nickel chromium iron, nickel chrome tungsten molybdenum, nickel cobalt,
8. An alloy containing at least one metal selected from the group consisting of nickel copper, silver, silver palladium, silver platinum, iron chromium nickel and iron chromium aluminum. Item 6. The solid oxide fuel cell according to item 1. 9. The method according to claim 9, wherein the electrically insulating and gas impermeable substrate comprises:
The solid electrolyte type according to any one of claims 1 to 8, wherein the solid electrolyte type is at least one selected from the group consisting of glass, ceramics, and a metal whose surface is coated with glass or ceramics. Fuel cell. 10. An electrode reaction part is laminated on both sides of the porous metal base A so that the porous metal base A is sandwiched between the air electrodes or the fuel electrodes, and a porous part is formed on one of the electrode reaction parts. A solid electrolyte fuel cell comprising a plurality of single cells formed by laminating porous metal substrates B in substantially the same direction as the laminating direction, wherein the electrode reaction section comprises an air electrode, a solid electrolyte, and a fuel electrode. The side of the laminate obtained by laminating in this order
A solid electrolyte type wherein the porous metal substrates A and B flow fuel gas or oxidizing gas and collect battery output from the electrode reaction section. Fuel cell. 11. The air electrode and / or the fuel electrode may be 5 to
The solid oxide fuel cell according to claim 10, wherein the thickness is 100 µm. 12. The solid oxide fuel cell according to claim 10, wherein said solid electrolyte has a thickness of 50 μm or less. 13. The method according to claim 10, wherein the porous metal substrate A and / or the porous metal substrate B has a thickness of 0.1 to 5 mm. Solid electrolyte fuel cell. 14. The solid electrolyte according to claim 10, wherein the electrically insulating and gas impermeable substrate is coated with a thickness of 0.02 to 10 mm. Type fuel cell. 15. The method according to claim 15, wherein the porous metal substrate A and / or the porous metal substrate B comprises nickel, nickel chromium, nickel chromium iron, nickel chromium tungsten molybdenum, nickel cobalt, nickel copper, silver, silver palladium, silver platinum, The solid oxide fuel cell according to any one of claims 10 to 14, wherein the alloy is an alloy containing at least one metal selected from the group consisting of iron chromium nickel and iron chromium aluminum. 16. The electric insulating / gas impermeable substrate is at least one selected from the group consisting of glass, ceramics, and a metal whose surface is coated with glass or ceramics. Claims 10-1
Item 6. The solid oxide fuel cell according to any one of Items 5. 17. A porous metal substrate A is provided on an annular electrode reaction portion.
A solid electrolyte fuel cell comprising a plurality of single cell constituent parts inscribed in a plurality of insertion holes provided in a porous metal substrate B, wherein the electrode reaction unit comprises an air electrode, a solid The side surface of the laminate obtained by laminating the electrolyte and anode in this order
A solid electrolyte type wherein the porous metal substrates A and B flow fuel gas or oxidizing gas and collect battery output from the electrode reaction section. Fuel cell. 18. The method according to claim 18, wherein the air electrode and / or the fuel electrode is 5 to
18. The solid oxide fuel cell according to claim 17, having a thickness of 100 [mu] m. 19. The solid oxide fuel cell according to claim 17, wherein said solid electrolyte has a thickness of 50 μm or less. 20. The method according to claim 17, wherein the porous metal substrate A and / or the porous metal substrate B has a thickness of 0.1 to 5 mm. Solid electrolyte fuel cell. 21. The solid electrolyte according to claim 17, wherein the electrically insulating and gas impermeable substrate is coated with a thickness of 0.02 to 10 mm. Type fuel cell. 22. The method according to claim 19, wherein the porous metal substrate A and / or the porous metal substrate B comprises nickel, nickel chromium, nickel chromium iron, nickel chromium tungsten molybdenum, nickel cobalt, nickel copper, silver, silver palladium, silver platinum, The solid oxide fuel cell according to any one of claims 17 to 21, wherein the alloy is an alloy containing at least one metal selected from the group consisting of iron chromium nickel and iron chromium aluminum. 23. The electric insulating and gas impermeable substrate is at least one selected from the group consisting of glass, ceramics, and metal whose surface is coated with glass or ceramics. Claims 17-2
Item 3. The solid oxide fuel cell according to any one of Items 2. 24. In manufacturing the solid oxide fuel cell according to any one of claims 1 to 9, (a)
An air electrode or a fuel electrode is laminated on the porous metal substrate A,
(B) laminating a solid electrolyte on the air electrode or the fuel electrode,
(C) stacking a fuel electrode or an air electrode on the solid electrolyte;
(D) a porous metal substrate B is laminated on the fuel electrode or the air electrode; (e) an electrically conductive / gas impermeable substrate is laminated on the porous metal substrate B; And / or covering the side surface of the laminate formed by the fuel electrode and the solid electrolyte with an electrically insulating / gas impermeable substrate, and (g) laminating steps (a) to
A method for manufacturing a solid oxide fuel cell, comprising joining a plurality of single cell structures obtained in (e) and the coating step (f) in a direction substantially the same as the lamination direction. 25. The method according to claim 25, wherein the laminating step (c) is performed after the side surfaces of the air electrode or the fuel electrode and the solid electrolyte are coated with an electrically insulating and gas impermeable substrate as the coating step (f). 25. The method for producing a solid oxide fuel cell according to claim 24. 26. In manufacturing the solid oxide fuel cell according to any one of claims 10 to 16,
(A) An air electrode or a fuel electrode is laminated on both surfaces of the porous metal substrate A, (b) a solid electrolyte is laminated on the air electrode or the fuel electrode, and (c) the air electrode or the fuel electrode and the solid electrolyte are laminated. The side surface of the laminate to be formed is covered with an electrically insulating and gas impermeable substrate, (d) a fuel electrode or an air electrode is laminated on both surfaces of the porous metal substrate B, and (e) a side surface of the fuel electrode or the air electrode. Is coated with an electrically insulating and gas impermeable substrate, and (f) laminating step (a)
And (b) a plurality of single-cell constituent parts obtained in the coating step (c) and a plurality of single-cell constituent parts obtained in the laminating step (d) and the covering step (e) are alternately arranged in substantially the same direction as the laminating direction. A method for manufacturing a solid oxide fuel cell, comprising joining continuously. 27. In manufacturing the solid oxide fuel cell according to any one of claims 17 to 27,
(A) the air electrode or the fuel electrode is coated on the side surface in the longitudinal direction of the porous metal substrate A; (b) the solid electrolyte is coated on the air electrode or the fuel electrode; and (c) the fuel electrode or the fuel electrode is coated on the solid electrolyte. Covering the air electrode, (d) providing a plurality of insertion holes in the porous metal substrate B, and (e) covering the insertion holes with the coating steps (a) to (c).
(F) covering both ends of the air electrode, the fuel electrode and the solid electrolyte in the longitudinal direction with an electrically insulating and gas impermeable substrate, and A method for manufacturing a solid oxide fuel cell, comprising joining an inner wall and the fuel electrode or the air electrode.