JP2002329513A - Single cell for fuel cell and solid electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized, high output and highly reliable single cell, cell plate, a stack for a fuel cell provided with these and a solid electrolyte fuel cell. SOLUTION: In the single cell for the fuel cell, a solid electrolyte layer 4 is arranged in a groove or a hole providing an air electrode layer 2 and a fuel electrode layer 3 on a substrate 1, a reaction field is formed in a solid electrolyte layer interface by joining the air electrode layer 2 and the fuel electrode layer 3 to the solid electrolyte layer 4, and a conductive material 8 is inserted in the substrate 1. Electron conductivity of the conductive material 8 is higher than that of a forming material of the air electrode layer 2 and the fuel layer 3. In the solid electrolyte fuel cell, the stack for the solid electrolyte fuel cell is used as a power generating element.

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) that uses a solid electrolyte to obtain electric energy by an electrochemical reaction, and more particularly, to a solid electrolyte sandwiched between electrode layers. The present invention relates to a single cell, a cell plate, a fuel cell stack including the same, and a solid oxide fuel cell.

[0002]

2. Description of the Related Art In recent years, fuel cells have attracted attention as a clean energy source capable of high energy conversion and friendly to the global environment, and applications as power sources for automobiles are being studied. 2. Description of the Related Art Solid oxide fuel cells (hereinafter abbreviated as “SOFC”) have been attracting attention as highly efficient fuel cells. However, since the electromotive force of a single fuel cell is as low as about 1 V, it is necessary to connect a plurality of single cells in series to form a stack in order to increase the voltage. Therefore, a stacking method is important. Further, when considering the application as a power source for automobiles, it is necessary to increase the output. One of the techniques for increasing the output of an SOFC is to reduce the thickness of a solid electrolyte or an electrode. JP-A-8-64
In the structure disclosed in Japanese Patent Application Publication No. 216 and the like, the current collecting function is insufficient, and a wiring structure for smoothly extracting a current is required.

[0003]

In the conventional fuel cell stack as described above, since the electrode portion also has a current collecting function, the thinner the electrode, the smaller the cross-sectional area of the conductive path, and the lower the electrical resistance. Becomes large. Further, if a separator or an interconnector is arranged between the cell elements in order to improve the current collection function, the ratio of the non-power generation elements in the fuel cell stack increases, and the output density decreases. Further, the conventional interconnector is exposed to both an oxidizing gas atmosphere and a reducing gas atmosphere at a high temperature, so high durability is required, and usable materials are limited. Furthermore, it is necessary to serialize the single cells in order to increase the voltage, but in a flat stack without a gas separator, it is extremely difficult to connect each single cell in series inside the stack. The external connection must be performed in series, and there are problems related to the complexity of the wiring structure and the increase in the number of components.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a highly reliable single cell that can be reduced in size and output.
An object of the present invention is to provide a cell plate, a stack for a fuel cell provided with these, and a solid oxide fuel cell.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by arranging a conductive material for collecting electricity in a predetermined shape. As a result, the present invention has been completed.

That is, the single cell for a fuel cell according to the present invention comprises a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer, which are arranged in grooves or holes provided in a conductive substrate or an insulating substrate. A single cell for a fuel cell, wherein the air electrode layer and the fuel electrode layer are electrically and mechanically joined to the solid electrolyte layer to form an electrochemical reaction field at the solid electrolyte layer interface; The substrate is characterized by being formed by penetrating a conductive material capable of conducting a current collected from the reaction field to the outside from a part of the upper surface to a part of the lower surface and where the groove or hole does not exist. I do.

In a preferred embodiment of the fuel cell unit cell according to the present invention, the electronic conductivity of the conductive material is equal to or higher than that of the material forming the air electrode layer and the fuel electrode layer. And

Further, the fuel cell plate according to the present invention provides the fuel cell unit cell in a two-dimensional and continuous manner in a direction substantially perpendicular to the laminating direction of the air electrode layer, the fuel electrode layer and the solid electrolyte layer. Alternatively, it is characterized by a plurality of intermittently joined ones.

In a preferred embodiment of the fuel cell plate according to the present invention, the conductive material is buried in a gap between the groove or hole and an adjacent groove or hole and in a direction in which the substrate extends. It is characterized by.

In another preferred embodiment of the fuel cell plate according to the present invention, the groove or hole is connected to three or more adjacent grooves or holes via a gas flow path.

In still another preferred embodiment of the cell plate for a fuel cell according to the present invention, a conductive material embedded in the extending direction of the substrate is provided on the front side or the back side of the substrate, A flow path is provided on the back side or the front side of the substrate.

Further, in the fuel cell stack according to the present invention, the fuel cell unit cell or the fuel cell cell plate may be placed in the same direction as the lamination direction of the air electrode layer, the fuel electrode layer and the solid electrolyte layer. It is characterized in that it is two-dimensionally connected and integrated.

In a preferred embodiment of the fuel cell stack according to the present invention, the fuel cell single cell or the conductive material is provided with an insulating portion, and one or a plurality of single cells are provided on the air electrode layer side and the fuel electrode layer side. A current collecting portion for collecting the current.

Further, another preferred embodiment of the fuel cell stack according to the present invention is characterized in that the average area Sc and the average area Sr satisfy a relationship of Sc / Sr ≧ 10.

Still another preferred embodiment of the fuel cell stack according to the present invention is characterized in that an insulating portion is provided on the fuel cell single cell or the conductive material and connected in series.

Further, the solid oxide fuel cell of the present invention comprises:
The solid oxide fuel cell stack is configured as a power generating element.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a single cell and a cell plate for 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. For convenience of description, one surface of each layer such as a single cell or an electrode layer is described as “upper surface, front surface”, and the other surface is described as “lower surface, back surface”, etc., but these are equivalent elements, and Needless to say, such a configuration is also included in the scope of the present invention. Further, the cell plate is a practical product form for promoting the integration of the single cells and increasing the output of the obtained fuel cell.

As described above, the single cell of the present invention comprises a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer, which is disposed on a substrate. Here, the substrate is, in particular, silicon (Si).
The present invention is not limited to the substrate, and any of a conductive substrate and an insulating substrate can be employed. For example, a glass substrate or a metal substrate can be used. Thus, the cost for the substrate can be reduced.
Further, the sandwiching body (the laminate of the air electrode layer, the solid electrolyte layer, and the fuel electrode layer) is arranged in a groove or a hole provided in the substrate.
Thus, a reaction field (power generation unit) formed by contact of the source gases (air gas and fuel gas) is fixed in a desired form. The grooves and holes can be formed into various shapes in consideration of the output when the fuel cell is used, the source gas flow path, and the like, and the depths of the grooves and holes are not particularly limited.

As a constituent material of the air electrode layer and the fuel electrode layer, for example, nickel (N
i) or copper (Cu) and cermets thereof can be used, and as the air electrode layer, LSM, LSC, Pt, Ag and the like can be used.

Further, the solid electrolyte layer is necessary for exhibiting a power generation function, and is a conventionally known material having oxygen ion conductivity, for example, neodymium oxide (Nd
₂ O _3), samarium oxide _{(Sm 2 O} 3), yttria _(Y 2 _{O 3)} and stabilized zirconia and the solid solution and gadolinium oxide _(Gd 2 _{O 3),} ceria (CeO ₂₎ solid solution, bismuth oxide And LaGaO ₃ can be used, but is not limited thereto.

In the single cell of the present invention, the air electrode layer and the fuel electrode layer are electrically and mechanically joined to the solid electrolyte layer to form an electrochemical reaction field at the solid electrolyte layer interface. In addition, a conductive material capable of conducting a current collected from the reaction field to the outside is penetrated from a part of the upper surface to a part of the lower surface and in a portion where the groove or the hole does not exist. It is characterized by the following. This reduces the DC resistance (resistance based on Ohm's law) when the stack is used,
Single cells can be connected in series in the stack. Further, since the conductive material is not exposed to the source gas, even a material having low durability can be used. Further, by using a material having high strength as the conductive material, the mechanical strength when the cell plate is formed can be improved.

For example, lanthanum-strontium-manganese (La-Sr-Mn) composite oxide, lanthanum-strontium-cobalt (La-
Sr-Co) composite oxide, lanthanum chromite, silver (A
g), nickel (Ni), copper (Cu), platinum (Pt) or iron (Fe), and alloys mainly comprising metals according to any combination thereof, and / or stainless steel. As described above, by selecting a material that can reduce the difference in thermal expansion coefficient between the other portions, the thermal shock when the stack is formed can be reduced, and the temperature of the fuel cell stack can be increased at a high speed. In addition, an electrode layer current collector having a high current collecting function and stable even at a high temperature can be formed. It is also effective to use a heating element such as a nickel-chromium alloy as the conductive material, and in this case, it can be used as a starting heat source for a stack or the like by energization.

Furthermore, it is preferable that the electronic conductivity of the conductive material is equal to or higher than the electronic conductivity of the material forming the air electrode layer and the fuel electrode layer. Thus, when the cell plate is formed, the temperature distribution in the cell plate can be made uniform, and the thermal durability of the stack can be improved. In addition, current collection in each electrode layer is likely to be smooth.

The cell plate for a fuel cell according to the present invention is characterized in that the above-mentioned single cell is two-dimensionally and continuously or intermittently arranged in a direction substantially perpendicular to the laminating direction of the air electrode layer, the fuel electrode layer and the solid electrolyte layer. And a plurality of them. In this case, the balance between the electric resistance and the power generation output can be adjusted by appropriately changing the number of single cells handled by the conductive material, which is effective. Here, the case where such a cell plate is formed by intermittently joining the unit cells means that the unit plate is a unit plate obtained by combining the unit cells of the present invention in which the conductive material is removed from the unit cells. In other words, a configuration is adopted in which a conductive material is provided for every two or more cell units.

Also, from the viewpoint of smooth current collection,
Preferably, the conductive material is buried in the gap between the groove or hole and the adjacent groove or hole and in the extending direction of the substrate to obtain a cell plate for a fuel cell. In this case, since the conductive material is buried in the empty space of the substrate, the dead space can be effectively used without reducing the reaction field (power generation unit). In addition, electron conductivity (function of collecting electrons generated by the reaction) can be improved. Furthermore, since the conductive material does not come into contact with gas, it is not necessary to consider gas durability at high temperatures. By embedding the conductive material in the horizontal direction (plane direction) in addition to the conductive material penetrating in the vertical direction (thickness direction) of the cell plate, the reaction field (power generation unit) can be expanded from a wider area. This is effective because current can be collected efficiently and the DC resistance can be reduced. Note that the “between grooves or holes” is not limited to all the grooves or holes, and it is needless to say that some of the grooves or holes in a cell unit composed of a plurality of single cells may be used. . Further, as the conductive material buried in the extending direction of the substrate, the same material as the conductive material penetrating substantially in the vertical direction can be used, and furthermore, both can be connected and arranged. Further, it is desirable to arrange as many conductive materials as to be embedded in the extending direction of the substrate as long as the strength and the like of the cell plate can be maintained.

It is preferable that the groove or hole communicates with three or more adjacent grooves or holes via a gas flow path. When the gas flows in only one direction, the flow of the gas may be interrupted by a conductive material that penetrates in a substantially vertical direction, but this is effective because it can be prevented. Further, the gas flow path can be arranged in a desired shape such as a mesh, for example,
A gas flow path as shown in FIG. 12 can be mentioned. When the cell plate is configured as a stack described later, such gas flow paths can be connected in the vertical direction (stacking direction).

Further, the conductive material buried in the extending direction of the substrate is disposed on the front side or the rear side of the substrate, and the gas flow path is disposed on the rear side or the front side of the substrate. Is preferably performed. For example, as shown in FIG. 12, by embedding a conductive member on the front surface and forming a gas flow path on the back surface, these can be arranged in a desired shape while securing the strength of the cell plate. If these are formed on the same surface, the conductive material is blocked by the gas flow path or the gas flow path is blocked by the conductive material, and it is difficult to arrange them in a desired shape. The cell plate thickness t, the depth d ₂ of the buried depth d ₁ and the gas flow path of the conductive material may satisfy the relation of t> d 1 ₊ d _2. In particular, in consideration of the strength of the cell substrate, it is desirable that the conductive material and the gas flow path have an interval of 5 μm or more. If the relationship of t> d ₁ + d ₂ is not satisfied, the burying depth and the depth of the gas flow path are too deep, penetrating the substrate, reducing the strength of the cell plate, and reducing the gas flow to the current collector. Contact and gas leakage.

Next, the stack for a solid oxide fuel cell according to the present invention will be described. Such a stack for a solid oxide fuel cell comprises two or more two-dimensionally connected single cells or cell plates for the fuel cell described above, which are two-dimensionally connected in the same direction as the lamination direction of the air electrode layer, the fuel electrode layer and the solid electrolyte layer. Become
When such a stack is used as a power generation element, a fuel cell having excellent output characteristics (suitable for an automobile power supply) can be obtained.

Further, the above-described single cell for a fuel cell or a conductive material
Insulation is provided on the material, and one or more single cells and air electrodes
To form a current collector that collects power on the layer side and fuel electrode layer side
Is preferred. In other words, the reaction field responsible for the electrode reaction and the current transport
Can be arbitrarily divided into a current collector and
Reduce DC resistance and connect single cells in series in a stack
be able to. The insulating parts are connected in series
For example, as shown in FIGS. 4 and 8
In addition, the insulating portion 11a for dividing the cell prevents the short circuit of the cell.
To separate the insulating part 11b and adjacent series parts
The portion 11c can be provided to form a series connection. Ma
In addition, as an insulator constituting the insulating portion, SiN, Al₂
O ₃(Alumina) and glass. on the other hand,
As shown in FIGS. 3 and 7, only the air electrode layer 2 of each cell is provided.
Only the connected air electrode layer side current collector 9 and fuel electrode layer 3
And the fuel electrode layer side current collector 10 connected to the
To form the parallel connection by providing the insulating portion 11 as described above.
Can also. In this case, current collection in each electrode layer is smooth
Easy to be.

Further, it is preferable that the average area Sc of the cross section or the vertical section of the current collecting portion is larger than the average area Sr of the cross section or the vertical section of the reaction field. Sc and the above average area Sr are Sc / Sr ≧ 1.
It is preferable to satisfy the relation of 0. In this case, the resistance of the electrode layer current collector can be sufficiently reduced, and current collection can be performed smoothly. When Sc / Sr is 10 or more, the conductivity is sufficient, the resistance is small, and there is no possibility that the output is reduced.

Next, the solid oxide fuel cell of the present invention will be described. Such a fuel cell is obtained by configuring the solid oxide fuel cell stack described above as a power generation element. Thus, since the stack is formed by penetrating the conductive material, the conductive material can be used as an interconnector (electrically conductive path), and the fuel cell can be easily made thinner and smaller.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings by way of examples and comparative examples, but the present invention is not limited to these examples.

In the following examples, cell plates (single cell plate A and single cell plate B) were prepared by using a silicon substrate (Si substrate), and a plurality of these were laminated. A battery was manufactured and its performance was evaluated.

(Example 1: Parallel connection) 1) Fabrication of substrate (How to fabricate μ cell) [1] (1) having a resistivity of 10 to 11 Ωcm mixed with antimony
00) Oriented single crystal silicon substrate (5 inch diameter, thickness 1.
0 mm), using a mirror-polished surface on one side,
This was cut with a dicing saw into a square of 5 cm square so that each side was in the (110) direction. This square was kept at 90 ° C. water: hydrogen peroxide: ammonium hydroxide =
After immersion treatment in a 5: 1: 0.05 mixed solution for 10 minutes, immersion in a 5% aqueous hydrofluoric acid solution for 1 minute and immersion in pure water for 1 minute, and then taking out, followed by drying with nitrogen gas injection, and immediately It was carried into a vacuum specification, multiple target sputtering system. The outer peripheral portion of the film formation surface of the square silicon substrate housed in the substrate holder of the apparatus was covered with an Inconel mask to prevent the peripheral portion from being formed. The film formation area was set to be a 4 cm square portion at the center of the square substrate.

2) Preparation of unit cell plate A The substrate temperature of the above-mentioned Si substrate was set to 70 using a radiant heater.
Raise the temperature to 0 ° C and use a metallic nickel target.
A nickel oxide film having a thickness of about 5000 ° was grown by RF sputtering. Next, the substrate temperature is lowered to 600 ° C.
10 mol% yttria-added stabilized zirconia (hereinafter, referred to as
Using a sintered target of “10YSZ”, a 10YSZ thin film having a thickness of about 2 μm was grown on the nickel oxide film. Further, the substrate temperature is lowered to 500 ° C.
Approximately 3000mm thick using LSM sintered target
Was grown. Thus, Si
A nickel oxide film, a 10YSZ film, and a polycrystalline LSM film were sequentially laminated on one surface of the substrate.

Next, as shown in FIG.
A PSG film having a thickness of about 5000 mm is deposited on both surfaces of the substrate by a normal pressure CVD method, and then the pattern shown in FIG. Then, only the transfer portion corresponding to the white portion was removed by immersion in a hydrofluoric acid-based etchant. Here, the reason why the area of the width of the etching pattern is narrow is to stop the etching in the middle of the substrate during the anisotropic etching. After the photoresist was removed by ashing, the Si substrate was immersed in an anisotropic etching solution of hydrazine hydrate kept at about 60 ° C. for about 8 hours, and as shown in FIG. The small opening 7 is formed in the surface of the substrate by etching.
To make the laminated thin film partially self-supporting. Next, the silicon substrate 1 was immersed in a hydrofluoric acid-based etchant to remove the protective PSG film 20. Subsequently, the substrate temperature was raised to 500 ° C. using a radiant heater on the surface on which the above-mentioned laminated film was not formed, and along a gas flow path by RF sputtering using a sintered target of metallic nickel. Thus, a nickel oxide film having a thickness of about 3000 ° was grown. Further, when the unit cell plates are stacked to form a stack, FIG.
And a part of the portion where the current collector and the electrode layer are in contact with each other so as to have a circuit configuration as shown in FIG. 4 (parallel connection, series connection).
1 ₂ O ₃ powder (material) was spray-coated to form an insulating film, and then an opening (cell hole) serving as a current collector was filled with a nickel metal paste and dried to form a current collector. The unit cell plate A was produced as described above. The size of each element is 1.0 mm × 1.0 mm for the opening, and the interval between the openings is 1.0 m.
m.

3) Preparation of single cell plate B The above silicon substrate was heated to 700 ° C. using a radiant heater, and was subjected to RF sputtering using a sintered LSM target to a thickness of about 5000 ° C. Polycrystalline L
An SM film was grown. Next, the substrate temperature was lowered to 600 ° C., and a 10 YSZ thin film having a thickness of about 2 μm was formed on the LSM film using a sintered target of 10 mol% yttria-added stabilized zirconia (hereinafter referred to as “10YSZ”). Grew. Next, the substrate temperature is lowered to 500 ° C.
Approximately 3000mm thick using a nickel metal target
Was grown. In this manner, the polycrystalline LSM film, 10YSZ
A film and a nickel oxide film were laminated.

Next, a PSG film having a thickness of about 5000 mm is deposited on both surfaces of the substrate by a normal pressure CVD method, and then the back surface of the silicon substrate (the back surface of the surface on which the 10YSZ film and the like are laminated).
Then, the pattern shown in FIG. 1 was transferred by photolithography, and only the transfer portion corresponding to the white portion in FIG. 1 was removed by immersion in a hydrofluoric acid-based etching solution. here,
The reason why the width of the etching pattern is small is that the etching stops halfway through the substrate during anisotropic etching. After the photoresist was removed by ashing, the substrate was immersed in an anisotropic etching solution of hydrazine hydrate kept at about 60 ° C. for about 8 hours, and the silicon substrate was made to conform to the above pattern as shown in FIG. Then, a small opening 7 is made in the substrate surface so that the laminated thin film is partially free standing. Next, the silicon substrate 1 is immersed in a hydrofluoric acid-based etching solution, and
Was removed. Subsequently, the substrate temperature was raised to 500 ° C. using a radiant heater on the surface on which the laminated film was not formed, and along a gas flow path by RF sputtering using a sintered target of LSM. Polycrystalline L with a thickness of about 3000mm
An SM film was grown. Further, when a stack is formed by stacking the unit cell plates, a part of the contact portion between the current collector and the electrode layer is formed of Al ₂ so that the circuit configuration shown in FIGS.
O ₃ powder (the material) to form a spray coating and the insulating coating,
Thereafter, an opening serving as a current collector was filled with a nickel metal paste and dried to form a current collector. As described above, the cell plate B
Was prepared. The size of each element is 1.0 mm for the opening
× 1.0 mm, and the interval between the openings was 1.0 mm.

4) Fabrication of Solid Oxide Fuel Cell (Lamination of Single Cell Plates) The same LSM air electrode layer material as the electrode layer material adhered to the flat surface of the single cell plate A prepared by the above procedure Is applied on the electrode layer on the flat surface of the unit cell plate A,
A slurry of the same nickel oxide fuel electrode layer material as the electrode layer material adhered to the outermost flat surface of the unit cell plate was applied on the flat surface electrode layer of the unit cell plate, as shown in FIG. Thus, the unit cell plates were stacked facing each other. After laminating them, they were fired at 600 ° C. in a firing furnace to produce a solid oxide fuel cell.

As shown in FIG. 3, the cell plate A was placed in an electric furnace.
A fuel cell in which two sheets and one unit cell plate B are stacked is installed,
The temperature was raised to 700 ° C., and an AC impedance measurement and a power generation test were performed using pure oxygen and pure hydrogen as raw material gases, respectively. As a result of AC impedance measurement, DC resistance is
0.5 Ω when the electrode layer collectors 9 and 10 are not formed
On the other hand, what was produced in this example was 0.03
It showed a small resistance value of Ω. As a result of the power generation test, the open electromotive force was 1.05 V and the maximum output was 0.8 W / cm ² .

(Example 2: Series connection) As shown in FIG. 4, a fuel cell in which five unit cells A and five unit cells B were stacked in an electric furnace was installed, and the temperature was raised to 700 ° C. A power generation test was performed using pure oxygen and pure hydrogen as raw material gases. The total voltage of the serial portion was 5.1 V, and the voltage was increased by serialization. As a result of the power generation test, the open electromotive force was 5.1 V and the maximum output was 3.2 W / cm ² .

Embodiment 3 Series Connection of Glass Substrates FIG. 6 shows a manufacturing process of the cell plate of this embodiment. FIG. 5 shows a cross-sectional view and a plan view of a part of the cell plate. (A) Using high silicate glass having a thickness of 0.5 mm and a size of 5 cm square as the substrate 1, six 2 mmφ cell holes 7 were machined. A part of these cell holes 7 was penetrated with a conductive material to form an electrode current collector 8. (B) Next, a silane coupling material is applied to the surface of the Si substrate as the temporary substrate 1 ′ and placed on the upper surface of the substrate 1.
Heat treatment was performed at 0 ° C. and the substrates were laminated. (C) YSZ was formed as a 1 μm-thick film as an electrolyte layer 4 in the cell hole 7 by a RF sputtering method in a desired pattern from the lower surface of the substrate using a vapor deposition mask. (D) Subsequently, an LSM was formed as a lower electrode layer 2 (3) by RF sputtering so as to have a thickness of 5 μm so as to directly adhere to the electrolyte layer 4 from the lower surface of the substrate. (E) The temporary substrate 1 ′ was peeled off and removed with a hydrofluoric acid-based etchant. (F) YSZ and Ni were formed as the upper electrode layer 3 (2) from the upper surface of the substrate by 5 μm by a two-source sputtering method. The cell plate thus produced was referred to as a cell plate A.

In the above manufacturing process, the step (d)
The lower electrode layer is formed by sputtering YSZ and Ni by two-source sputtering.
A cell plate having an upper electrode layer of 5 μm formed by RF sputtering on the upper electrode layer in step (g) was
And In the same manner as in Example 2, the power generation characteristics were evaluated at 500 ° C. using a fuel cell in which five unit cells A and five unit cells B were stacked as shown in FIG. Open end voltage 4.5
V and the output was 1.05 W / cm ² .

(Embodiment 4: Series Connection of Glass Substrates) A manufacturing process of the cell plate of this embodiment is shown in FIG. FIG. 9 shows a cross-sectional view and a plan view of a part of the cell plate. (A) Using high silicate glass having a thickness of 0.5 mm and a 5 cm square as the substrate 1, six 2 mmφ cell holes 7 and a groove (size) 12 to be the electrode current collector 8 were processed. (B) Next, a silane coupling material is applied to the surface of the Si substrate as the temporary substrate 1 ′ and placed on the upper surface of the substrate 1.
Heat treatment was performed at 0 ° C. and the substrates were laminated. (C) YSZ was formed as a 1 μm-thick film as an electrolyte layer 4 in the cell hole 7 by a RF sputtering method in a desired pattern from the lower surface of the substrate using a vapor deposition mask. (D) Subsequently, an LSM was formed as a lower electrode layer 2 (3) by RF sputtering so as to have a thickness of 5 μm so as to directly adhere to the electrolyte layer 4 from the lower surface of the substrate. (E) Further, the temporary substrate 1 'was peeled off and removed with a hydrofluoric acid-based etching solution. (F) Further, a groove (size) 12 on the upper surface of the substrate was filled with a nickel metal paste and dried to form an electrode current collector 8. (G) YSZ and Ni were formed as the upper electrode layer 3 (2) from the upper surface of the substrate by 5 μm by a two-source sputtering method. The cell plate thus produced was referred to as a cell plate A.

In the above manufacturing process, the step (d)
To form a lower electrode layer 2 (3) with a thickness of 5 μm using YSZ and Ni by a two-source sputtering method, and to form an upper electrode layer 3 (2) in a step (g).
Was used as a single cell plate B in which LSM was formed to 5 μm by RF sputtering. An electrode current collector 8 was formed by penetrating a conductive material into a predetermined cell hole 7. In the same manner as in Example 2, the fuel cell in which the five unit cells A and the five unit cells B were stacked as shown in FIGS.
The power generation characteristics were evaluated at 0 ° C. The open-circuit voltage was 4.3 V and the output was 0.98 W / cm ² .

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, in the present invention, the shape and the like of the single cell and the cell plate can be arbitrarily selected, and a solid oxide fuel cell according to the desired output can be manufactured.

[0047]

As described above, according to the present invention, since the conductive material for collecting current is arranged in a predetermined shape, it is possible to reduce the size, increase the output, and obtain a highly reliable unit. It is possible to provide a cell, a cell plate, a fuel cell stack including the same, and a solid oxide fuel cell.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an etching pattern of a substrate.

FIG. 2 is a sectional view and a perspective view showing an example of a fuel cell stack.

FIG. 3 is a sectional view and a circuit diagram showing another example of a fuel cell stack.

FIG. 4 is a sectional view and a circuit diagram showing still another example of a fuel cell stack.

5A and 5B are a cross-sectional view and a plan view illustrating an example of a part of a cell plate.

FIG. 6 is a cross-sectional view illustrating an example of a manufacturing process of the cell plate.

FIG. 7 is a sectional view and a circuit diagram showing another example of a fuel cell stack.

FIG. 8 is a sectional view and a circuit diagram showing still another example of a fuel cell stack.

FIG. 9 is a sectional view and a plan view showing another example of a part of the cell plate.

FIG. 10 is a cross-sectional view showing another example of the manufacturing process of the cell plate.

FIG. 11 is a sectional view and a perspective view showing another example of a fuel cell stack.

FIG. 12 is a sectional view showing another example of the etching pattern of the substrate.

[Explanation of symbols]

 Reference Signs List 1 substrate (glass substrate) 1 'temporary substrate 2 air electrode 3 fuel electrode 4 electrolyte 5 air gas flow path 6 fuel gas flow path 7 cell hole 8 current collector (conductive part) 9 air electrode layer current collector 10 fuel electrode layer Current collector 11, 11a, 11b, 11c Insulator 12 Groove (size) 13 Reaction field (power generator) 20 Protective PSG film

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tadashi Shibata Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Masaharu Hatano 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa, Nissan Motor Co., Ltd. 72) Inventor Naoki Hara 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Fumi Sato 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Mitsugu Yamanaka Kanagawa Prefecture Nissan Motor Co., Ltd., 2 Takara-cho, Kanagawa-ku, Yokohama-shi (72) Inventor Makoto Uchiyama 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. F-term (reference) 5H026 AA06 CC00 CC03 CV00 EE08 EE13 HH02 HH03

Claims (14)

[Claims] 1. A single cell for a fuel cell comprising a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer and arranged in a groove or a hole provided in a conductive substrate or an insulating substrate, The air electrode layer and the fuel electrode layer are electrically and mechanically joined to the solid electrolyte layer to form an electrochemical reaction field at the solid electrolyte layer interface. A unit cell for a fuel cell, wherein a conductive material capable of conducting a current collected from the reaction field to the outside penetrates into a part and a portion where the groove or hole does not exist. 2. The unit cell for a fuel cell according to claim 1, wherein the electronic conductivity of the conductive material is equal to or higher than the electronic conductivity of the material forming the air electrode layer and the fuel electrode layer. 3. The method according to claim 1, wherein the conductive material is at least one selected from the group consisting of lanthanum-strontium-manganese composite oxide, lanthanum-strontium-cobalt composite oxide, lanthanum chromite, silver, nickel, copper, platinum and iron. 3. The unit cell for a fuel cell according to claim 1, wherein the unit cell is made of an alloy containing any one of the above and / or stainless steel. 4. The fuel cell unit according to claim 1, wherein the single cell for a fuel cell is two-dimensionally arranged in a direction substantially perpendicular to a laminating direction of the air electrode layer, the fuel electrode layer and the solid electrolyte layer. A cell plate for a fuel cell, wherein a plurality of cells are continuously or intermittently joined. 5. The fuel cell plate according to claim 4, wherein said conductive material is buried in a gap between said groove or hole and an adjacent groove or hole and in a direction in which said substrate extends. . 6. The cell plate for a fuel cell according to claim 4, wherein said groove or hole is communicated with three or more adjacent grooves or holes via a gas flow path. 7. A conductive material buried in an extending direction of the substrate is provided on a front side or a back side of the substrate, and the gas flow path is provided on a back side or a front side of the substrate. The fuel cell plate according to claim 6, wherein the cell plate is made of a fuel cell. 8. The thickness t of the cell plate, the depth d ₁ of burying the conductive material, and the depth d ₂ of the gas flow path are t> d ₁ + d _2.
The fuel cell plate according to claim 6, wherein the following relationship is satisfied. 9. The fuel cell unit cell according to any one of claims 1 to 3, or the fuel cell panel according to any one of claims 4 to 8, A stack for a solid oxide fuel cell, comprising a plurality of two-dimensionally connected and integrated two-dimensionally in substantially the same direction as the lamination direction of an air electrode layer, a fuel electrode layer and a solid electrolyte layer. 10. An insulating portion is provided on the fuel cell single cell or the conductive material, and a current collecting portion for collecting power on the air electrode layer side and the fuel electrode layer side is formed for one or more single cells. The stack for a solid oxide fuel cell according to claim 9, wherein: 11. The solid electrolyte fuel according to claim 10, wherein an average area Sc of a cross section or a vertical section of the current collector is larger than an average area Sr of a cross section or a vertical section of the reaction field. Stack for batteries. 12. The average area Sc and the average area Sr
Satisfies the relationship of Sc / Sr ≧ 10, the stack for a solid oxide fuel cell according to claim 11, wherein 13. The solid electrolyte fuel cell according to claim 9, wherein an insulating portion is provided on the fuel cell unit cell or the conductive material and connected in series. stack. 14. A solid oxide fuel cell comprising the solid oxide fuel cell stack according to any one of claims 9 to 13 as a power generating element.