JP4807605B2 - STACK FOR SOLID ELECTROLYTE FUEL CELL AND SOLID ELECTROLYTE FUEL CELL - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid electrolyte fuel cell (SOFC) that uses a solid electrolyte and obtains electric energy by an electrochemical reaction, and more specifically, a fuel cell including a single cell in which a solid electrolyte is sandwiched between electrode layers. The present invention relates to a stack and a solid oxide fuel cell.
[0002]
[Prior art]
In recent years, fuel cells have been attracting attention as clean energy sources that are capable of high energy conversion and are friendly to the global environment, and their application as power sources for automobiles is being studied.
Solid oxide fuel cells (hereinafter abbreviated as “SOFC”) are 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 form a stack by connecting a plurality of single cells in series in order to increase the voltage, so the stacking method is important.
Also, when considering application as a power source for automobiles, it is necessary to increase the output, and one of the technologies for increasing the output of SOFC is to reduce the thickness of the solid electrolyte and electrode. The structure disclosed in Japanese Patent Application Laid-Open No. 8-64216 or the like has an insufficient current collecting function and requires a wiring structure for smoothly extracting current.
[0003]
[Problems to be solved by the invention]
In the conventional fuel cell stack as described above, since the electrode portion also serves as a current collecting function, when the electrode is thinned, the cross-sectional area of the conductive path is reduced and the electric resistance is increased.
Further, if a separator or an interconnector is disposed between the cell elements in order to improve the current collecting function, the proportion of the non-power generation elements in the fuel cell stack increases, and the output density decreases.
Furthermore, since the conventional interconnector is exposed to both an oxidizing gas atmosphere and a reducing gas atmosphere at a high temperature, high durability is required and usable materials are limited.
Furthermore, in order to increase the voltage, it is necessary to connect single cells in series. However, in a flat stack without a gas separator, it is very difficult to connect each single cell in series inside the stack. There is a problem related to complicated wiring structure and an increase in the number of components because serial connection must be performed outside.
[0004]
Accordingly, an object of the present invention is to provide a solid oxide fuel cell stack and a solid oxide fuel cell that can be reduced in size and output and are highly reliable.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by arranging the conductive material responsible for current collection in a predetermined shape, and the present invention has been completed. It was.
[0006]
The stack for a solid oxide fuel cell according to claim 1, wherein the solid electrolyte layer is sandwiched between the air electrode layer and the fuel electrode layer to be electrically and mechanically joined, and an electrochemical reaction occurs at the interface of the solid electrolyte layer. A fuel cell unit plate in which a single cell for a fuel cell forming a field is disposed in a plurality of grooves or holes provided in a conductive substrate or an insulating substrate, and the groove or hole of each of the cell plates for a fuel cell It is a non-existing part, and a conductive material for conducting the current collected from the reaction field to the outside from a part of the upper surface of the fuel cell plate to a part of the lower surface is penetrated, and those A fuel cell plate is integrated by connecting two conductive materials penetrating in series to each other and two-dimensionally connecting them in the same direction as the air electrode layer, fuel electrode layer, and solid electrolyte layer. It is characterized by that.
[0007]
The stack for a solid oxide fuel cell according to claim 2 is a material for forming an air electrode layer and a fuel electrode layer in which the electronic conductivity of the conductive material penetrating the cell plate for fuel cell according to claim 1 is the same. It is more than electronic conductivity.
[0008]
The solid oxide fuel cell stack according to claim 3, wherein the conductive material penetrating the fuel cell plate according to claim 1 is a lanthanum-strontium-manganese composite oxide, lanthanum-strontium-cobalt. It consists of a complex oxide, lanthanum chromite, an alloy comprising at least one selected from the group consisting of silver, nickel, copper, platinum and iron, and / or stainless steel.
[0009]
The stack for a solid oxide fuel cell according to claim 4 includes a groove or a hole adjacent to the groove or hole disposed in the fuel cell plate according to any one of claims 1 to 3. The conductive material is embedded in the gap and the extending direction of the substrate.
[0010]
The solid oxide fuel cell stack according to claim 5 is characterized in that the conductive material embedded in the extending direction of the fuel cell plate according to claim 4 is a surface side or back surface of the fuel cell plate. The gas flow path is disposed on the back side or the front side of the fuel cell plate.
[0011]
The stack for a solid oxide fuel cell according to claim 6 includes the thickness t of the cell plate, the embedding depth d1 of the conductive material, and the gas flow path according to any one of claims 1 to 5. The depth d2 satisfies the relationship t> d1 + d2.
[0012]
The stack for a solid oxide fuel cell according to claim 7 is provided with an insulating portion in the single cell for fuel cell or the conductive material according to any one of claims 1 to 6, and for one or a plurality of fuel cells. A current collecting unit for collecting current for each unit cell and for the air electrode layer side and the fuel electrode layer side is formed.
[0013]
In the stack for a solid oxide fuel cell according to claim 8, the average area Sc of the cross section or vertical section of the current collector described in claim 7 is greater than the average area Sr of the cross section or vertical section of the reaction field. It ’s a big one.
[0014]
In the solid oxide fuel cell stack according to claim 9, the average area Sc described in claim 8 and the average area Sr satisfy the relationship of Sc / Sr ≧ 10.
[0015]
The stack for a solid oxide fuel cell according to claim 10 is provided with an insulating portion in the single cell for fuel cell or the conductive material according to any one of claims 1 to 9.
[0016]
The stack for a solid oxide fuel cell according to claim 11 comprises the stack for a solid oxide fuel cell according to any one of claims 1 to 10 as a power generation element.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the single cell and the cell plate for the solid oxide fuel cell of the present invention will be described in detail. In the present specification, “%” indicates a mass percentage unless otherwise specified.
For convenience of explanation, 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 are mutually replaced. It goes without saying that such a configuration is also included in the scope of the present invention. Furthermore, the cell plate is a practical product form for promoting the integration of single cells and increasing the output of the resulting fuel cell.
[0018]
As described above, the unit cell of the present invention is formed by sandwiching a solid electrolyte layer between an air electrode layer and a fuel electrode layer, and arranging this on a substrate.
Here, the substrate is not particularly limited to a silicon (Si) 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. Thereby, the cost concerning a board | substrate can be reduced.
Moreover, the said clamping body (laminated body of an air electrode layer, a solid electrolyte layer, and a fuel electrode layer) is arrange | positioned in the groove | channel or hole provided in the board | substrate. Thus, the reaction field (power generation unit) formed by the contact of the raw material gas (air gas and fuel gas) is fixed in a desired form. Such grooves and holes can be formed in various shapes in consideration of the output of the fuel cell, the raw material gas flow path, and the like, and the depths of the grooves and holes are not particularly limited.
[0019]
Moreover, as a constituent material of the said air electrode layer and a fuel electrode layer, nickel (Ni) or copper (Cu), these cermets, etc. can be used as a fuel electrode layer, for example, LSM can be used as LSM. , LSC, Pt, and Ag can be used.
[0020]
Further, the solid electrolyte layer is necessary for developing a power generation function, and is a conventionally known material having oxygen ion conductivity, such as neodymium oxide (Nd ₂ O ₃ ), Samarium oxide (Sm ₂ O ₃ ), Yttria (Y ₂ O ₃ ) And gadolinium oxide (Gd) ₂ O ₃ ) And the like, and stabilized ceria (CeO ₂ ) System solid solution, bismuth oxide and LaGaO ₃ However, the present invention is not limited to this.
[0021]
The unit cell of the present invention is characterized in that 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 interface of the solid electrolyte layer. And a conductive material capable of conducting the current collected from the reaction field to the outside from a part of the upper surface to a part of the lower surface and not having the groove or hole. And
Thus, the direct current resistance (resistance based on Ohm's law) when the stack is formed can be reduced, and single cells can be connected in series in the stack. In addition, since the conductive material is not exposed to the source gas, even a material having low durability can be used. Furthermore, by using a material having high strength as the conductive material, the mechanical strength when the cell plate is constructed can be improved.
[0022]
For example, as the conductive material, lanthanum-strontium-manganese (La-Sr-Mn) composite oxide, lanthanum-strontium-cobalt (La-Sr-Co) composite oxide, lanthanum chromite, silver (Ag), nickel ( Ni), copper (Cu), platinum (Pt) or iron (Fe), and alloys mainly containing metals according to any combination thereof, and / or stainless steel can be used. In this way, by selecting a material that can alleviate the difference in thermal expansion coefficient of other portions, it is possible to alleviate the heat shock when the stack is formed, and to raise the temperature of the fuel cell stack at high speed. In addition, an electrode layer current collector having a high current collecting function and stable even at high temperatures can be formed.
In addition, it is also effective to use a heating element such as a nickel-chromium alloy as the conductive material. In this case, it can be used as a heat source for starting up a stack or the like by energization.
[0023]
Furthermore, the electronic conductivity of the conductive material is preferably 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 configured, the temperature distribution in the cell plate can be made uniform, and the thermal durability of the stack can be improved. Moreover, current collection in each electrode layer tends to be smooth.
[0024]
In the fuel cell plate according to the present invention, a plurality of the above-described single cells are two-dimensionally and continuously or intermittently provided in a direction substantially perpendicular to the stacking direction of the air electrode layer, the fuel electrode layer, and the solid electrolyte layer. Joined. In this case, it is effective because 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.
Here, the case where the cell plate is formed by intermittently joining the single cells means that the cell plate is a cell plate formed by combining single cells having a configuration in which the conductive material is removed from the single cell of the present invention. In other words, a conductive material is provided for every two or more cell units.
[0025]
In addition, from the surface where current is collected more smoothly, the conductive material is buried in the gap between the groove or the hole and the groove or hole adjacent to the groove or in the extending direction of the substrate to obtain a fuel cell plate. Is preferred.
In this case, since the conductive material is embedded 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. In addition to the conductive material penetrating in the vertical direction (thickness direction) of the cell plate, the conductive material is also embedded in the horizontal direction (plane direction), so that a wider reaction field (power generation unit) can be obtained. It is effective because current can be collected efficiently and direct current resistance can be reduced.
In addition, it is needless to say that “between grooves or holes” is not limited to all the grooves or holes, and may be a part of grooves or holes in a cell unit constituted by a plurality of single cells. . Further, as the conductive material embedded in the extending direction of the substrate, the same material as the conductive material penetrating substantially in the vertical direction can be used, and the both can be connected and arranged. Further, it is desirable to dispose a large amount of conductive material embedded in the extending direction of the substrate as long as the strength of the cell plate can be maintained.
[0026]
Further, it is preferable that the groove or hole communicates with three or more adjacent grooves or holes through a gas flow path. If the gas is circulated in only one direction, the gas flow may be blocked by the conductive material penetrating substantially in the vertical direction, which is effective because it can be prevented. Further, the gas flow path can be arranged in a desired shape such as a mesh shape, for example, a gas flow path as shown in FIG. When the cell plate is configured as a stack described later, it is possible to connect the gas flow paths in the vertical direction (stacking direction).
[0027]
Furthermore, the conductive material embedded in the extending direction of the substrate is disposed on the front side or the back side of the substrate, and the gas flow path is disposed on the back side or the front side of the substrate. Is preferred. 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 ensuring 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.
In addition, the cell plate thickness t, the embedding depth d of the conductive material ₁ And the depth d of the gas flow path ₂ But t> d ₁ + D ₂ It is better to satisfy the relationship. In particular, considering 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. T> d ₁ + D ₂ If the above relationship is not satisfied, the embedded depth and the gas flow path are too deep, the substrate penetrates, the strength of the cell plate decreases, the gas contacts the current collector, and the gas leaks. There are things to do.
[0028]
Next, the stack for the solid oxide fuel cell of the present invention will be described.
Such a solid oxide fuel cell stack is formed by connecting a plurality of the above-mentioned single cells or cell plates for a fuel cell two-dimensionally in substantially the same direction as the stacking direction of the air electrode layer, fuel electrode layer, and solid electrolyte layer. It is made up of. When such a stack is used as a power generation element, a fuel cell excellent in output characteristics (suitable for an automobile power source) can be obtained.
[0029]
In addition, it is preferable that an insulating part is provided in the single cell or the conductive material for the fuel cell to form a current collecting part for collecting current on one or a plurality of single cells and on the air electrode layer side and the fuel electrode layer side. is there. That is, it can be arbitrarily divided into a reaction field responsible for electrode reaction and a current collector responsible for current transport, and the direct current resistance of the stack can be reduced, and single cells can be connected in series in the stack.
The insulating part can be provided so as to be connected in series. For example, as shown in FIGS. 4 and 8, the insulating part 11a for dividing the cell, the insulating part 11b for preventing the short circuit of the cell, and the adjacent series. An insulating part 11c that divides the parts can be provided to form a series connection. Further, as the insulator constituting the insulating portion, SiN, Al ₂ O ₃ Examples include (alumina) and glass.
On the other hand, as shown in FIGS. 3 and 7, the air electrode layer side current collector 9 connected only to the air electrode layer 2 of each cell, and the fuel electrode layer side current collector connected only to the fuel electrode layer 3. The insulating part 11 may be provided so as to form the electric part 10 to form a parallel connection. At this time, current collection in each electrode layer tends to be smooth.
[0030]
Furthermore, the average area Sc of the cross section or vertical section of the current collector is preferably larger than the average area Sr of the cross section or vertical section of the reaction field, specifically, the average area Sc and the above It is preferable that the average area Sr satisfies the relationship Sc / Sr ≧ 10. In this case, the resistance of the electrode layer current collector can be made sufficiently small, and current can be collected smoothly. Note that when the Sc / Sr is 10 or more, the conductivity is sufficient and the resistance is small, and there is no fear that the output is lowered.
[0031]
Next, the solid oxide fuel cell of the present invention will be described.
Such a fuel cell is obtained by configuring the above-described solid oxide fuel cell stack as a power generation element. As a result, since the conductive material is formed in a stack, the conductive material can be used as an interconnector (electric conduction path), and the fuel cell can be easily made thin and small.
[0032]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail with reference to drawings, this invention is not limited to these Examples.
[0033]
In the following examples, cell plates (unit cell plate A and unit cell plate B) are produced using a silicon substrate (Si substrate), and a plurality of these are laminated to produce a solid oxide fuel cell of each example. The performance was evaluated.
[0034]
(Example 1: Parallel connection)
1) Fabrication of substrate (How to make μ cell)
As a (100) -oriented single crystal silicon substrate (5 inch diameter, thickness 1.0 mm) having a resistivity of 10 to 11 Ωcm mixed with antimony, one side of which is mirror-polished is used for each side with a dicing saw. Was cut into a square shape of 5 cm square so as to be in the (110) direction. This square product was immersed in a mixed solution of water: hydrogen peroxide: ammonium hydroxide = 5: 1: 0.05 kept at 90 ° C. for 10 minutes, and then purified with a 5% hydrofluoric acid aqueous solution for 1 minute. It was taken out after being immersed in water for 1 minute, and was then carried into an ultra-high vacuum specification, multi-target sputtering apparatus immediately after drying by nitrogen gas injection. With respect to the film formation surface of the square silicon substrate housed in the substrate holder of the apparatus, the outer edge portion was covered with an Inconel mask so that the peripheral portion was not formed. The film formation area was set to be a 4 cm square portion of the central portion of the square substrate.
[0035]
2) Manufacture of cell plate A
The substrate temperature was raised to 700 ° C. using a radiation heater on the Si substrate, and a nickel oxide film having a thickness of about 5000 mm was grown by RF sputtering using a metallic nickel target.
Next, the substrate temperature is lowered to 600 ° C., and a 10 mol% yttria-added stabilized zirconia (hereinafter referred to as “10YSZ”) sintered body target is used, and a 10 YSZ thin film having a thickness of about 2 μm is formed on the nickel oxide film. Grew.
Further, the substrate temperature was lowered to 500 ° C., and a polycrystalline LSM film having a thickness of about 3000 mm was grown using a sintered compact target of LSM.
In this way, a nickel oxide film, a 10YSZ film, and a polycrystalline LSM film were sequentially laminated on one side of the Si substrate.
[0036]
Next, as shown in FIG. 1, a PSG film having a thickness of about 5000 mm is deposited on both surfaces of the Si substrate 1 by atmospheric pressure CVD, and then the back surface of the Si substrate 1 (the back surface of the surface on which the 10YSZ film or the like is laminated). 1), the pattern shown in FIG. 1 was transferred by photolithography, and only the transfer portion corresponding to the white portion was removed by immersion in a hydrofluoric acid etching solution. Here, the reason why the width of the etching pattern is narrow is that the etching stops in the middle of the substrate during anisotropic etching.
After the photoresist is removed by ashing, the Si substrate is immersed in an anisotropic etching solution of hydrazine hydrate kept at about 60 ° C. for about 8 hours. As shown in FIG. According to the above, etching is removed and a small opening 7 is formed in the substrate surface so that the laminated thin film is partially self-supporting. Next, the silicon substrate 1 was immersed in a hydrofluoric acid-based etching solution, and the protective PSG film 20 was removed.
Subsequently, with respect to the surface where the laminated film is not formed, the substrate temperature is raised to 500 ° C. using a radiation heater, and along the gas flow path by RF sputtering using a sintered nickel metal target. Thus, a nickel oxide film having a thickness of about 3000 mm was grown.
Further, when the cell plates are stacked to form a stack, one of the portions where the current collector and the electrode layer are in contact with each other so that the circuit configuration is as shown in FIG. 3 and FIG. 4 (parallel connection, series connection). Part with Al ₂ O ₃ Powder (material) was spray-coated to form an insulating film, and then a nickel metal paste was filled in the opening (cell hole) serving as a current collector and dried to obtain a current collector.
A single battery plate A was produced as described above. The size of each element part was 1.0 mm × 1.0 mm in the opening part, and the interval between the opening parts was 1.0 mm.
[0037]
3) Manufacture of cell plate B
With respect to the silicon substrate, the substrate temperature was raised to 700 ° C. using a radiation heater, and a polycrystalline LSM film having a film thickness of about 5000 mm was grown by RF sputtering using a sintered compact target of LSM.
Next, the substrate temperature is lowered to 600 ° C., and a 10 YSZ thin film having a thickness of about 2 μm is formed on the LSM film using a sintered target of 10 mol% yttria-added stabilized zirconia (hereinafter referred to as “10YSZ”). Grown up.
Next, the substrate temperature was lowered to 500 ° C., and a nickel oxide film having a thickness of about 3000 mm was grown using a metallic nickel target. In this manner, a polycrystalline LSM film, a 10YSZ film, and a nickel oxide film were sequentially laminated on one surface of the silicon substrate.
[0038]
Next, a PSG film having a thickness of about 5000 mm is deposited on both surfaces of the substrate by atmospheric pressure CVD, and then the pattern shown in FIG. 1 is applied to the back surface of the silicon substrate (the back surface of the surface on which the 10YSZ film or the like is laminated). Transfer was performed by a lithography method, 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 narrow is that the etching stops in the middle of the substrate during anisotropic etching.
After removing the photoresist by ashing, the substrate is immersed in an anisotropic etching solution of hydrazine hydrate kept at about 60 ° C. for about 8 hours, and the silicon substrate is made to correspond to the above pattern as shown in FIG. Etching is removed to make a small opening 7 in the substrate surface so that the laminated thin film is partially self-supporting. Next, the silicon substrate 1 was immersed in a hydrofluoric acid-based etching solution, and the protective PSG film 20 was removed.
Subsequently, with respect to the surface where the laminated film is not formed, the substrate temperature is raised to 500 ° C. using a radiation heater, and RF sputtering is performed along the gas flow path using an LSM sintered body target. A polycrystalline LSM film having a thickness of about 3000 mm was grown.
Further, when a stack is formed by stacking unit cell plates, 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 FIGS. ₂ O ₃ Powder (material) was spray-coated to form an insulating film, and then the nickel metal paste was filled into the opening serving as the current collector, and dried to form a current collector.
A single battery plate B was produced as described above. The size of each element part was 1.0 mm × 1.0 mm in the opening part, and the interval between the opening parts was 1.0 mm.
[0039]
4) Production of solid oxide fuel cell (lamination of each cell plate)
A slurry of the same LSM air electrode layer material as the electrode layer material deposited on the flat surface of the unit cell plate A produced by the above procedure is applied onto the electrode layer on the flat surface of the unit cell plate A, and then Then, a slurry of the same nickel oxide fuel electrode layer material as the electrode layer material deposited on the outermost surface of the flat surface of the unit cell plate is applied on the electrode layer of the flat surface of the unit cell plate, and FIG. As shown, the single cell plates were stacked facing each other. After stacking them, they were fired at 600 ° C. in a firing furnace to produce a solid oxide fuel cell.
[0040]
As shown in FIG. 3, a fuel cell in which two unit cell plates A and one unit cell plate B are stacked is installed in an electric furnace, heated to 700 ° C., and pure oxygen and pure hydrogen are used as source gases, respectively. AC impedance measurement and power generation test were conducted.
As a result of AC impedance measurement, the DC resistance was 0.5Ω when the electrode layer current collectors 9 and 10 were not formed, whereas the resistance produced by this example was as small as 0.03Ω. showed that.
Moreover, as a result of the power generation test, an open electromotive force of 1.05 V and a maximum output of 0.8 W / cm ² Met.
[0041]
(Example 2: Series connection)
As shown in FIG. 4, a fuel cell in which five cell plates A and five cell plates B are stacked in an electric furnace is installed, heated to 700 ° C., and pure oxygen and pure hydrogen are used as source gases, respectively. A power generation test was conducted.
The total voltage of the series part was 5.1 V, and the voltage was increased by serialization. Moreover, 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 Met.
[0042]
(Example 3: Glass substrate serial connection (1))
The manufacturing process of the cell board of a present Example is shown in FIG. FIG. 5 shows a cross-sectional view and a plan view of a part of the cell plate.
(A) Six holes of 2 mmφ cell holes 7 were processed using a high silicate glass of 0.5 mm thickness and 5 cm square as the substrate 1. A conductive material was penetrated into a part of these cell holes 7 to form an electrode current collector 8.
(B) Next, a silane coupling material was applied to the surface of the Si substrate as the temporary substrate 1 ′, placed on the upper surface of the substrate 1, and heat-treated at 200 ° C. for bonding.
(C) Using an evaporation mask from the lower surface of the substrate, 1 μm of YSZ was formed as an electrolyte layer 4 in the cell hole 7 in a desired pattern by RF sputtering.
(D) Subsequently, 5 μm of LSM was formed by RF sputtering so that the lower electrode layer 2 (3) was directly adhered to the electrolyte layer 4 from the lower surface of the substrate.
(E) The temporary substrate 1 ′ was peeled and removed with a hydrofluoric acid-based etching solution.
(F) From the upper surface of the substrate, 5 μm of YSZ and Ni were formed as the upper electrode layer 3 (2) by the two-source sputtering method.
The single battery plate thus produced was designated as single battery plate A.
[0043]
Further, in the above manufacturing process, the unit cell plate in which the lower electrode layer is formed with 5 μm of YSZ and Ni by the two-source sputtering method in the step (d), and the upper electrode layer is formed with LSM of 5 μm by the RF sputtering method in the step (g). Was designated as a unit cell plate B.
In the same manner as in Example 2, the power generation characteristics were evaluated at 500 ° C. using a fuel cell in which the above single cell plate A and five single cell plates B were laminated as shown in FIG. Open end voltage 4.5V, output 1.05W / cm ² Met.
[0044]
(Example 4: glass substrate series connection (2))
The manufacturing process of the cell board of a present Example is shown in FIG. FIG. 9 shows a cross-sectional view and a plan view of a part of the cell plate.
(A) Using a high-silicate glass having a thickness of 0.5 mm and a 5 cm square as a substrate 1, six 2 mmφ cell holes 7 and a groove (size) 12 to be an electrode current collector 8 were processed.
(B) Next, a silane coupling material was applied to the surface of the Si substrate as the temporary substrate 1 ′, placed on the upper surface of the substrate 1, and heat-treated at 200 ° C. for bonding.
(C) Using an evaporation mask from the lower surface of the substrate, 1 μm of YSZ was formed as an electrolyte layer 4 in the cell hole 7 in a desired pattern by RF sputtering.
(D) Subsequently, 5 μm of LSM was formed by RF sputtering so that the lower electrode layer 2 (3) was directly adhered to the electrolyte layer 4 from the lower surface of the substrate.
(E) Further, the temporary substrate 1 ′ was peeled and removed with a hydrofluoric acid-based etching solution.
(F) Further, the groove (size) 12 on the upper surface of the substrate was filled with a nickel metal paste and dried to form the electrode current collector 8.
(G) From the upper surface of the substrate, 5 μm of YSZ and Ni were formed as the upper electrode layer 3 (2) by the two-source sputtering method.
The single battery plate thus produced was designated as single battery plate A.
[0045]
Further, in the above manufacturing process, the lower electrode layer 2 (3) is formed to have a thickness of 5 μm by YSZ and Ni by the two-source sputtering method in the step (d), and the upper electrode layer 3 (2) is RF sputtered from the LSM in the step (g). A cell plate formed by the method was formed as a cell plate B.
Further, a conductive material was inserted into the predetermined cell hole 7 to form an electrode current collector 8.
In the same manner as in Example 2, the power generation characteristics were evaluated at 500 ° C. using a fuel cell in which the above unit cell plate A5 and unit cell plate B5 were stacked as shown in FIGS. Open end voltage 4.3V, output 0.98W / cm ² Met.
[0046]
As mentioned above, although this invention was demonstrated in detail by the Example, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this 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 target output can be produced.
[0047]
【The invention's effect】
As described above, according to the present invention, since the conductive material responsible for current collection is arranged in a predetermined shape, it is possible to reduce the size and increase the output, and the highly reliable single cell, cell plate, A fuel cell stack and a solid oxide fuel cell including these can be provided.
[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 cross-sectional view and a perspective view showing an example of a fuel cell stack.
FIG. 3 is a cross-sectional view and a circuit diagram showing another example of a fuel cell stack.
FIG. 4 is a cross-sectional view and a circuit diagram showing still another example of a fuel cell stack.
FIG. 5 is a cross-sectional view and a plan view showing an example of a part of a cell plate.
FIG. 6 is a cross-sectional view showing an example of a manufacturing process of a cell plate.
FIG. 7 is a cross-sectional view and a circuit diagram showing another example of a fuel cell stack.
FIG. 8 is a cross-sectional view and a circuit diagram showing still another example of a fuel cell stack.
FIG. 9 is a cross-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 cross-sectional view and a perspective view showing another example of a fuel cell stack.
FIG. 12 is a cross-sectional view showing another example of the etching pattern of the substrate.
[Explanation of symbols]
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 Insulating part
12 Groove (size)
13 Reaction Field (Power Generation Unit)
20 Protective PSG film

Claims (11)

A single cell for a fuel cell that sandwiches a solid electrolyte layer between an air electrode layer and a fuel electrode layer and is electrically and mechanically joined to form an electrochemical reaction field at the interface of the solid electrolyte layer is formed as a conductive substrate or A fuel cell plate disposed in a plurality of grooves or holes provided in the insulating substrate;
In each of the fuel cell plate, there is no groove or hole for conducting the current collected from the reaction field from a part of the upper surface to a part of the lower surface of the fuel cell plate to the outside. While penetrating conductive material,
The conductive materials penetrating into the fuel cell plate were connected in series with each other, and two-dimensionally connected and integrated in the same direction as the stacking direction of the air electrode layer, the fuel electrode layer, and the solid electrolyte layer. A stack for a solid oxide fuel cell . 2. The solid oxide fuel cell stack according to claim 1, wherein an electronic conductivity of the conductive material penetrating the fuel cell plate is equal to or higher than an electronic conductivity of a material forming the air electrode layer and the fuel electrode layer. The conductive material penetrating the fuel cell plate is selected from the group consisting of lanthanum-strontium-manganese composite oxide, lanthanum-strontium-cobalt composite oxide, lanthanum chromite, silver, nickel, copper, platinum and iron. The stack for a solid oxide fuel cell according to claim 1 or 2, wherein the stack comprises at least one alloy comprising at least one kind and / or stainless steel. 4. The fuel cell plate according to claim 1, wherein the conductive material is embedded in the gap between the groove or hole disposed in the cell plate for the fuel cell and the groove or hole adjacent thereto and in the extending direction of the substrate. A stack for a solid oxide fuel cell according to Item . The conductive material embedded in the extending direction of the fuel cell plate is disposed on the front side or back side of the fuel cell plate, and the conductive material is disposed on the back side or front side of the fuel cell plate. The stack for a solid oxide fuel cell according to claim 4, wherein a gas flow path is provided . The solid according to any one of claims 1 to 5, wherein a thickness t of the cell plate, an embedding depth d1 of the conductive material, and a depth d2 of the gas flow path satisfy a relationship of t> d1 + d2. Stack for electrolyte fuel cell . 2. An insulating part is provided in the single cell or conductive material for the fuel cell, and a current collecting part for collecting current on the air electrode layer side and the fuel electrode layer side is formed for each one or a plurality of fuel cell single cells. The stack for a solid oxide fuel cell according to any one of -6 . The stack for a solid oxide fuel cell according to claim 7, 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 . 9. The solid oxide fuel cell stack according to claim 8, wherein the average area Sc and the average area Sr satisfy a relationship of Sc / Sr ≧ 10 . The stack for a solid oxide fuel cell according to any one of claims 1 to 10, wherein an insulating part is provided in the single cell or the conductive material for the fuel cell. A solid oxide fuel cell comprising the stack for a solid oxide fuel cell according to claim 1 as a power generation element .

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