JP2008059793A - Horizontally-striped fuel cell and fuel cell - Google Patents

Abstract

[PROBLEMS] To reduce the risk of external contact and disconnection by forming a connection member between a solid electrolyte and a porous support, rather than using an external terminal for electrical connection between the cell surface and the cell back surface. A fuel cell and a fuel cell that can be prevented and have high reliability are provided.
In a horizontally striped fuel cell in which power generation elements are formed on the front and back surfaces of a porous support, the power generation elements on both surfaces of the porous support facing each other at the cell tip are The porous support 11 is electrically connected by a connecting member 30 between the opposing surfaces disposed on the surface and / or inside thereof.
[Selection] Figure 4

Description

  The present invention relates to a horizontal stripe fuel cell and a fuel cell.

  In recent years, various types of fuel cells in which a cell stack formed by connecting a plurality of fuel cells is accommodated in a storage container have been proposed as next-generation energy. As such a fuel cell, various types such as a polymer electrolyte fuel cell, a phosphoric acid fuel cell, a molten carbonate fuel cell, and a solid electrolyte fuel cell are known. In particular, solid electrolyte fuel cells have advantages such as high power generation efficiency and high operating temperatures of 700 ° C. to 1000 ° C., so that the exhaust heat can be used, and research and development are being promoted. .

  FIG. 11 is an enlarged longitudinal sectional view showing a part of a conventional solid oxide fuel cell. This solid electrolyte fuel cell is called a horizontal stripe type, and a fuel electrode 3a, a solid electrolyte 3b and an air electrode 3c are formed on the surface of a cylindrical support 11 (hereinafter referred to as an insulating support) that is a porous insulator. A plurality of power generating elements 3 having a multilayer structure that are sequentially stacked are formed at predetermined intervals in the axial length direction shown in FIG. The power generating elements 3 adjacent to each other are electrically connected in series by inter-element connection members (interconnectors) 4 respectively. That is, the fuel electrode 3 a of one power generation element 3 and the air electrode 3 c of the other power generation element 3 are connected by the inter-element connection member 4.

A gas flow path 12 is formed inside the insulating support 11.
In the horizontally-striped fuel cell, the oxygen ion conductivity of the solid electrolyte 3b increases at 600 ° C. or higher. Therefore, a gas containing oxygen flows through the air electrode 3c at such a temperature, and a gas containing hydrogen flows through the fuel electrode 3a. By flowing, the oxygen concentration difference between the air electrode 3c and the fuel electrode 3a is increased, and a potential difference is generated between the air electrode 3c and the fuel electrode 3a.

Due to this potential difference, oxygen ions move from the air electrode 3c to the fuel electrode 3a through the solid electrolyte 3b. The moved oxygen ions are combined with hydrogen at the fuel electrode 3a to become water, and at the same time, electrons are generated at the fuel electrode 3a.
That is, the electrode reaction of the following formula (1) occurs in the air electrode 3c, and the electrode reaction of the following formula (2) occurs in the fuel electrode 3a.

Air electrode 3c: 1 / 2O ₂ + 2e− → O ² − (1)
Fuel electrode 3a: O ² − + H ₂ → H ₂ O + 2e− (2)
Then, by electrically connecting the fuel electrode 3a and the air electrode 3c, electrons move from the fuel electrode 3a to the air electrode 3c, and an electromotive force is generated between both electrodes.
Thus, in the solid oxide fuel cell, by supplying oxygen and hydrogen, the above reaction is continuously caused to generate an electromotive force to generate electric power (see, for example, Patent Document 1).
In the horizontally striped fuel cell, a plurality of power generating elements 3 that cause the above reaction are formed on the surface of the insulating support 11 in the axial direction and connected in series, so that a high voltage can be obtained with a small number of cells. There is an advantage that

In a horizontally striped hollow flat solid electrolyte fuel cell having a power generation element 3 formed on the front and back surfaces of the insulating support, the electrical connection between the front and back surfaces of the insulating support is performed in series. As shown in FIG. 10, the connection between the power generation element (not shown) at the front end of the insulating support and the power generation element (not shown) at the front end of the insulation support is performed around the outside of the cell. A method using a metal band is known (for example, see Patent Document 2). Reference numeral 8 denotes an inter-cell connecting member that connects power generating elements of adjacent fuel cells.
JP 10-003932 A JP 2006-019059 A

However, when the electrical connection between the power generating elements on the front and back surfaces of the insulating support is performed by an external terminal made of a metal band, this external terminal is outside the solid electrolyte and exposed, so contact with the outside or disconnection The risk was high. Contact with the outside has a risk of electric leakage, and disconnection has a risk that the entire bundle cannot be generated.
An object of the present invention is to provide an electrical connection between power generating elements on both surfaces of a porous support in a horizontally striped solid oxide fuel cell in which power generating elements are formed on both surfaces of the porous support. Rather than using external terminals, the formation of an inter-face connection member between the solid electrolyte and the porous support prevents the risk of contact with the outside and disconnection, and is a highly reliable horizontal stripe type It is in providing a fuel cell and a fuel cell.

  As a result of intensive studies to solve the above problems, the present inventors have made a porous inter-face connection member that electrically connects the power generating elements on both surfaces of the support facing each other at the cell tip. It has been found that the risk of leakage and disconnection due to contact with the outside can be prevented by disposing on the surface and / or inside of the support, and the present invention has been completed.

That is, the fuel cell and the fuel cell in the present invention have the following configurations.
(1) A plurality of power generating elements each having a multilayer structure in which an inner electrode, a solid electrolyte, and an outer electrode are sequentially laminated on both opposing surfaces of an electrically insulating porous support having a gas flow path therein; In each of the opposing surfaces of the porous support, an inner electrode of one of the power generating elements is electrically connected to an outer electrode of the other power generating element adjacent to the one power generating element, In the horizontally striped fuel cell in which a plurality of power generation elements are connected in series, the power generation elements on both surfaces of the porous support facing each other at the cell tip are on the surface and / or inside of the porous support. A horizontally-striped fuel cell, wherein the fuel cell is electrically connected by a connecting member between opposed surfaces.
(2) The horizontal stripe fuel cell according to (1), wherein the connecting member between the opposing surfaces is disposed over the entire circumference between the porous support and the solid electrolyte.
(3) The horizontal stripe fuel cell according to (1), wherein the connecting member between the opposing surfaces is configured to penetrate through the porous support member from one surface to the other surface facing the connecting member. cell.
(4) The horizontal stripe fuel cell according to any one of (1) to (3), wherein the facing-surface connecting member is made of an electrode material or a metal.
(5) A fuel cell comprising a plurality of horizontally-striped fuel cells according to any one of (1) to (4) stored in a storage container.

According to (1) to (3), the laterally striped fuel cell of the present invention is provided with an inter-face connection member that electrically connects the power generating elements on both surfaces of the porous support facing each other at the cell tip. By forming it inside the solid electrolyte, the connecting member between the opposing surfaces is protected by the solid electrolyte, and it is possible to prevent the risk of leakage and disconnection due to contact with the outside, and to provide a highly reliable horizontal stripe fuel cell. .
According to (4), since an electrode material or a metal is used for the connecting member between the opposing surfaces, the connection resistance between the power generating elements on both surfaces of the porous support is reduced. The generated power can be efficiently extracted from the cell.
According to the fuel cell of the present invention, by using a plurality of horizontal stripe fuel cells having improved power generation performance, a high power generation amount can be obtained with a small number of horizontal stripe fuel cells.

Hereinafter, an embodiment of a horizontal stripe fuel cell according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a partially broken perspective view showing the structure of a horizontally striped fuel cell of the present invention, and FIG. 2 is a cell surface view and a cell back view of the tip portion thereof. This fuel cell 1 has a plurality of power generating elements 13 along the axial length direction of the insulating support 11 on both opposing surfaces of a hollow flat plate-like electrically insulating porous support (hereinafter referred to as an insulating support 11). A plurality of such elements are arranged, and these are connected in series via the inter-element connection member 17. A plurality of power generating elements 13 are respectively formed on the front and back surfaces of the insulating support 11 that face each other.

  3A is a cross-sectional view taken along the line AA in FIG. 2, and the inter-facing surface connection member 30 circulates between the insulating support 11 and the solid electrolyte 13b, and the cell surface at the cell tip portion. (Insulation support surface) The power generation element 13 of 1a and the power generation element 13 of the cell back surface (insulation support back surface) 1b are shown connected. In this connection, the direction of current on the cell surface 1a is opposite to the direction of current on the cell back surface 1b. That is, the power generating elements 13 on the front and back surfaces of the cell (insulating support) are connected in series. FIG. 3B is a cross-sectional view taken along the line BB in FIG.

  FIG. 4 is a cross-sectional view taken along the line C-C in FIG. 3A, and is a vertical cross-sectional view of a cell showing a portion where the power generating element 13 is formed. The fuel cell 1 is configured by arranging a plurality of power generating elements 13 on the front and back surfaces of the insulating support 11 at predetermined intervals in the axial length direction. Each power generating element 13 has a layer structure in which a current collecting fuel electrode layer 23, an active fuel electrode layer 13a, a solid electrolyte 13b, and an air electrode layer 13c are sequentially stacked.

  The power generating elements 13 adjacent to each other on the front and back surfaces of the insulating support 11 are connected in series by an inter-element connection member 17 including a first current collecting layer 17a and a second current collecting layer 17b. That is, the first current collecting layer 17a is formed on the active fuel electrode layer 13a of the one power generating element 13, and the first current collecting layer 17a includes the both ends in the axial length direction and is surrounded by the solid electrolyte 13b. It is covered in a sealed state and exposed in a strip shape from the solid electrolyte 13b. The exposed portion of the first current collecting layer 17a is covered with the second current collecting layer 17b, and this second current collecting layer 17b is formed on the air electrode layer 13c of the other power generating element 13, thereby generating power. The elements 13 are electrically connected in series.

  The insulating support 11 is porous, and a plurality of fuel gas passages 12 with small inner diameters are separated by partition walls 51 (see FIG. 1) and extend in the axial length direction. Is provided. The number of the gas flow paths 12 is preferably 2 to 14, for example, and more preferably 6 to 10 in terms of power generation performance and structural strength. In this way, by forming a plurality of gas flow paths 12 inside the insulating support 11, the insulating support 11 is flattened compared to the case where one large gas flow path is formed inside the insulating support 11. It is possible to increase the power generation amount by increasing the area of the power generation element 13 per volume of the fuel cell 1. Therefore, the number of cells for obtaining the required power generation amount can be reduced. In addition, the number of connection points between cells can be reduced.

  By flowing a fuel gas (hydrogen gas) through the gas flow path 12 and exposing the air electrode layer 13c to an oxygen-containing gas such as air, the above-described equation (1) is obtained between the active fuel electrode layer 13a and the air electrode layer 13c. ), Electrode reaction shown in (2) occurs, a potential difference is generated between the two electrodes, and power is generated.

As shown in FIGS. 3 and 4, the above-described feature of the present embodiment is that when the power generating elements 13 formed on the cell surface 1 a and the cell back surface 1 b are electrically connected to each other at the cell tip, the insulating support 11 It is connected with the connection member 30 between opposing surfaces formed so that it may circulate around the surface of this. The facing inter-surface connection member 30 extends an active fuel electrode layer 13a and a current collecting fuel electrode layer 23 formed on one surface (for example, the cell surface 1a) of the insulating support 11 to the cell tip E side. The extended portion is formed so as to extend to the other surface of the insulating support 11 and surround the outer surface of the insulating support 11. The active fuel electrode layer 13a and the collector fuel electrode layer 23 are not extended to the cell tip E side, but from the side surfaces of the active fuel electrode layer 13a and the collector fuel electrode layer 23 through the side surface of the insulating support 11. Thus, the opposing surface connecting member 30 may be formed by forming the insulating support 11 up to the other surface. At this time, the first current collecting layer 17a of the inter-element connection member 17 is disposed on the opposing inter-surface connection member 30 extending on the opposite side (for example, the cell back surface 1b). The first current collecting layer 17 a and the air electrode 13 c at the tip of the cell on the same surface are electrically connected by the second current collecting layer 17 b of the inter-element connection member 17. However, at this time, insulation is ensured by the electrolyte material between the fuel electrode layers 13a, 23 at the tip of the opposite side (for example, the cell back surface 1b) and the inter-facing surface connecting member 30. Moreover, the electrolyte material is also filled around the first current collecting layer 17a to form a gas sealed state (see FIG. 4).
Thereby, the connection member 30 between opposing surfaces is protected by electrolyte material (electrolyte), and can prevent the danger of the electric leakage by the contact with the exterior, or a disconnection.

  A plurality of the fuel cells 1 are assembled to assemble a cell stack as shown in FIG. A conductive member (not shown) for taking out the electric power generated in the cell stack to the outside of the fuel cell is attached to both ends of the cell stack, and accommodated in a storage container to produce a fuel cell. An oxygen-containing gas such as air is introduced into the storage container, and a fuel gas such as hydrogen is introduced into the fuel gas manifold 50 through an introduction pipe. The fuel gas is introduced into the gas flow path 12 of the fuel cell 1 through the fuel gas manifold 50 and introduced upward, and the remaining fuel gas is discharged from the tip E of the fuel cell 1. If the fuel cell 1 is heated to a predetermined temperature, the fuel cell 1 can generate electric power. The used fuel gas and oxygen-containing gas are discharged out of the storage container.

As shown in FIG. 5, the fuel cells 1 are electrically connected to each other via an inter-cell connection member 19 disposed at the lower end.
That is, at the lower end portion of the cell stack, the inter-element connection member 17 is provided at the lower end portion of one fuel cell 1 and is electrically connected to the active fuel electrode layer 13a of the one fuel cell. The inter-element connection member 17 is electrically connected to the air electrode layer 13 c of the other fuel cell 1 via the inter-cell connection member 19.
Thus, since the above-mentioned fuel battery cells 1 are electrically connected to each other via the inter-cell connecting member 19, the cell stack can arrange the fuel battery cells 1 densely, and the power generation amount The volume of the hit cell stack can be reduced. Therefore, a small and highly efficient cell stack can be provided. In the present invention, the cell tip refers to the end of the fuel cell 1 on the side opposite to the side connected to the manifold 50, in other words, the fuel cell 1 on the downstream side (discharge side) of the fuel gas. The end of

Hereinafter, the material of each member constituting the fuel cell 1 will be described in detail.
(Insulating support)
The insulating support 11 according to the present invention is made of Ni or Ni oxide (NiO) and a rare earth element oxide. Examples of rare earth elements constituting rare earth element oxides include Y, La, Yb, Tm, Er, Ho, Dy, Gd, Sm, and Pr. Preferably, Y ₂ O ₃ or Yb ₂ O ₃ , especially Y ₂ O ₃ .

The Ni or NiO (NiO is usually reduced by hydrogen gas and present as Ni during power generation) is 10 to 25% by volume in terms of NiO, particularly 15 to 20% by volume in the insulating support 11. It should be contained.
The thermal expansion coefficient of the insulating support 11 is usually about 10.5 to 12.5 × 10 ⁻⁶ (1 / K).

The insulating support 11 needs to be electrically insulating in order to prevent an electrical short circuit between the power generating elements 13, and it is generally desirable that the insulating support 11 has a resistivity of 10 Ω · cm or more. When the content of Ni or the like exceeds the above range, the electric resistance value tends to decrease. Further, when the content of Ni or the like is less than the above range, it is not different from the case where a rare earth element oxide (for example, Y ₂ O ₃ ) is used alone, and it is difficult to adjust the thermal expansion coefficient with the power generation element 13. Tend to be.

Further, the remaining amount other than Ni or the like is usually at least one kind of rare earth element oxide. However, other oxides such as MgO and SiO ₂ or composite oxides such as calcium zirconate may be contained in a small amount, for example, in the range of 5% by mass or less.
The insulating support 11 must be able to introduce the fuel gas in the fuel gas flow path 12 up to the surface of the active fuel electrode layer 13a, and therefore needs to be porous. In general, the open porosity should be 25% or more, especially in the range of 30-40%.

(Fuel electrode layer)
The fuel electrode layer causes the electrode reaction of the above formula (2). In the present embodiment, the active fuel electrode layer 13a on the solid electrolyte 13b side and the current collecting fuel electrode layer 23 on the insulating support 11 side. And a two-layer structure.
The active fuel electrode layer 13a on the solid electrolyte 13b side is formed of a known porous conductive ceramic. For example, it is composed of ZrO ₂ (stabilized zirconia) in which a rare earth element is dissolved, and Ni and / or NiO (hereinafter referred to as Ni or the like). As the stabilized zirconia in which the rare earth element is dissolved, the same one used for the solid electrolyte 13b described later is preferably used.

The stabilized zirconia content in the active fuel electrode layer 13a is preferably in the range of 35 to 65% by volume, and the content of Ni or the like is 65 to 35% in terms of NiO in order to exhibit good current collecting performance. % Should be in the range.
Further, the open porosity of the active fuel electrode layer 13a is preferably 15% or more, particularly preferably in the range of 20 to 40%.

The thermal expansion coefficient of the active fuel electrode layer 13a is usually about 12.3 × 10 ⁻⁶ (1 / K).
The active fuel electrode layer 13a has a thickness of 5 to 5 because it absorbs thermal stress generated due to the difference in thermal expansion from the solid electrolyte 13b and prevents cracking or peeling of the active fuel electrode layer 13a. It is desirable to be in the range of 15 μm.
In the fuel electrode layer, the current collecting fuel electrode layer 23 on the insulating support 11 side is a mixture of Ni or Ni oxide and rare earth element oxide, like the insulating support 11.

The Ni or Ni oxide (NiO is usually reduced by hydrogen gas and present as Ni during power generation) is contained in the rare earth element oxide in a range of 30 to 60% by volume in terms of NiO. Is good. By adjusting within this range, the difference in thermal expansion between the insulating support 11 and the current collecting fuel electrode layer 23 can be made 2 × 10 ⁻⁵ (1 / K) or less.
The current collecting fuel electrode layer 23 needs to be conductive so as not to impair the flow of current, and it is generally desirable that the current collecting fuel electrode layer 23 have a conductivity of 400 S / cm or more. From the viewpoint of having good electrical conductivity, the content of Ni or the like is desirably 30% by volume or more.

The thermal expansion coefficient of the current collecting fuel electrode layer 23 is usually about 11.5 × 10 ⁻⁶ (1 / K).
In addition, the thickness of the current collecting fuel electrode layer 23 is desirably 80 μm or more from the viewpoint of improving electric conductivity.
As described above, if the fuel electrode is formed in two layers, the active fuel electrode layer 13a on the solid electrolyte 13b side and the current collecting fuel electrode layer 23 on the insulating support member 11 side, the collector electrode on the insulating support member 11 side is used. By adjusting the Ni amount or NiO amount in terms of NiO of the electrofuel electrode layer 23 within the range of 30 to 60% by volume, the thermal expansion coefficient thereof will be described later without impairing the bondability with the power generating element 13. The thermal expansion coefficient of the solid electrolyte 13b can be approached, and for example, the difference in thermal expansion between the two can be less than 2 × 10 ⁻⁶ (1 / K). Therefore, since the thermal stress generated due to the difference in thermal expansion between the two during the production, heating, and cooling of the fuel battery cell 1 can be reduced, cracking and peeling of the fuel electrode can be suppressed. . Therefore, even when fuel gas (hydrogen gas) is flowed to generate power, the consistency of the thermal expansion coefficient with the insulating support 11 is stably maintained, and cracks due to thermal expansion differences can be effectively avoided. .

(Solid electrolyte)
The solid electrolyte 13b is composed of a dense ceramic made of stabilized ZrO ₂ composed of ZrO ₂ which was a solid solution of rare earth or an oxide thereof.
Here, as rare earth elements to be dissolved or oxides thereof, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc. Or these oxides etc. are mentioned, Preferably, Y, Yb, or these oxides are mentioned. The solid electrolyte 13b is a lanthanum gallate system (LaGaO ₃ ) having a thermal expansion coefficient substantially equal to that of stabilized ZrO ₂ (8 mol% Yttoria Stabilized Zirconia, hereinafter referred to as “8YSZ”) in which 8 mol% of Y is dissolved. System) solid electrolytes. The solid electrolyte 13b has a thickness of 10 to 100 μm, for example, and has a relative density (according to Archimedes method) of 93% or more, preferably 95% or more.
Such a solid electrolyte 13b has a function as an electrolyte for bridging electrons between electrodes, and at the same time has a gas barrier property to prevent leakage of fuel gas or oxygen-containing gas (gas permeation). .

(Air electrode layer)
The air electrode layer 13c is made of conductive ceramics. Examples of conductive ceramics include ABO ₃ type perovskite oxides. Examples of such perovskite oxides include transition metal type perovskite oxides, preferably LaMnO ₃ oxides, LaFeO ₃ oxides. Examples thereof include transition metal type perovskite oxides having La at the A site, such as oxides based on oxides and LaCoO ₃ oxides. More preferably, from the viewpoint of high electrical conductivity at a relatively low temperature of about 600 to 1000 ° C., a LaCoO ₃ oxide is used.
In the perovskite oxide described above, La and Sr may coexist at the A site, and Fe, Co, and Mn may coexist at the B site.
Such an air electrode layer 13c can cause the electrode reaction of the above-described formula (1).
Further, the air electrode layer 13c has an open porosity of, for example, 20% or more, and preferably 30 to 50%. If the open porosity is within the above-described range, the air electrode layer 13c can have good gas permeability.
Moreover, the thickness of the air electrode layer 13c is set in a range of 30 to 100 μm, for example. If it exists in an above-described range, the air electrode layer 13c can have favorable current collection property.

(Element connection member)
An inter-element connection member 17 (first current collecting layer 17a and second current collecting layer 17b) used for connecting adjacent power generating elements 13 in series is connected to the active fuel electrode layer 13a of one power generating element 13 and The other electrode element 13c is connected to the air electrode layer 13c of the other power generation element 13, and these are formed of conductive ceramics. However, since they are in contact with an oxygen-containing gas such as fuel gas (hydrogen gas) and air, they are resistant to reduction. It is necessary to have oxidation resistance.
For this reason, conductive ceramics, metal, and metal glass containing glass can be used as the inter-element connection member 17, and the lanthanum chromite perovskite oxide (LaCrO ₃ oxide) is used as the conductive ceramic. used. In order to prevent leakage of fuel gas passing through the gas flow path 12 in the insulating support 11 and oxygen-containing gas such as air passing outside the air electrode layer 13c, such conductive ceramics must be dense. For example, it is preferable to have a relative density (Archimedes method) of 93% or more, particularly 95% or more. In addition, a sealing property can also be improved by interposing an appropriate bonding layer (for example, Y ₂ O ₃ ) between the end face of the first current collecting layer 17a and the end face of the solid electrolyte 13b.
The first current collecting layer 17a may have a two-layer structure of a metal layer and a metal glass layer containing glass. The metal layer is made of, for example, an alloy of Ag and Ni, and the metal glass layer is made of Ag and glass. Due to the metal glass layer, the fuel gas passing through the gas flow path 12 in the insulating support 11 leaks to the second current collecting layer 17b, and the oxygen-containing gas passes outside the air electrode layer 13c to the metal layer. Can be effectively prevented. Moreover, as the 2nd current collection layer 17b, the porous layer comprised, for example from Ag-Pd can be used.
The inter-element connection member 17 electrically connects the fuel electrode layer 13a of one power generation element 13 and the air electrode layer 13c of the other power generation element 13 adjacent to each other. It is comprised from the current collection layer 17b, and these are electrically connected.

  In the above-described example, the power generating element 13 formed on the insulating support 11 has a layer structure in which the inner electrode is the active fuel electrode layer 13a and the outer electrode is the air electrode layer 13c. However, it is of course possible to reverse the positional relationship between the two electrodes. That is, the power generation element 13 can be formed by laminating the air electrode layer 13c, the solid electrolyte 13b, and the active fuel electrode layer 13a in this order on the insulating support 11. In this case, an oxygen-containing gas such as air is introduced into the gas flow path 12 of the insulating support 11, and the fuel gas is supplied to the outer surface of the active fuel electrode layer 13a that is the outer electrode.

(Connecting member between opposing surfaces)
The inter-facing surface connection member 30 is not particularly limited as long as it electrically connects the electrodes described above, and is, for example, the same as the fuel electrode layer (the active fuel electrode layer 13a and / or the current collecting fuel electrode layer 23). Materials can be used. Preferably, a Ni—Y ₂ O ₃ layer used as the current collecting fuel electrode 23 is used. Further, the thickness is desirably 50 to 200 μm. By setting the thickness to 50 μm or more, the resistance can be reduced.
Moreover, the opposing surface connection member 30 can use the metal which consists of at least 1 type or more of Pt, Ag, Ni base alloy, and a Fe-Cr steel alloy.
By using an electrode material or a metal for the connecting member 30 between the opposing surfaces, the connection resistance between the front and back surfaces of the fuel cell 1 is reduced, so that the generated power can be efficiently taken out from the fuel cell.
In the above embodiment, the case where the facing inter-surface connection member 30 is formed of two layers by extending the active fuel electrode layer 13a and the current collecting fuel electrode layer 23 has been described. Instead of extending the layer 13a and the current collecting fuel electrode layer 23, the inter-facing surface connecting member may be formed as a single layer. In this case, the thickness of the connecting member between the opposing surfaces is preferably the total thickness of the active fuel electrode layer 13a and the current collecting fuel electrode layer 23. Further, the facing inter-surface connection member can be formed of a material different from that of the active fuel electrode layer 13a and the current collecting fuel electrode layer 23.

(Cell connecting member)
The inter-cell connection member 19 is electrically connected to the air electrode layer 13c of the other fuel battery cell 1, and electrically connects the one inter-element connection member 17 and the air electrode layer 13c of the other fuel battery cell 1 described above. If it does, it will not restrict | limit in particular, For example, it forms from a heat resistant metal, conductive ceramics, etc.
Further, by applying a conductive adhesive such as a paste containing a noble metal such as Ag or Pt to the connection portion between the inter-cell connection member 19, the inter-element connection member 17 and the air electrode layer 13c, the inter-cell connection The connection reliability of the member 19 can also be improved.

(Production method)
Next, a method for manufacturing the horizontal stripe fuel cell described above will be described with reference to FIGS.

First, the insulating support body molded body 11 is produced. As a material of the insulating support molded body 11, an MgO powder having an average particle size (D ₅₀ ) (hereinafter simply referred to as “average particle size”) on a volume basis is 0.1 to 10.0 μm, and if necessary, thermal expansion is performed. Ni powder, NiO powder, Y ₂ O ₃ powder, rare earth element stabilized zirconia powder (YSZ), etc. are mixed at a predetermined ratio and mixed for coefficient adjustment or bonding strength improvement, and thermal expansion after mixing The coefficient is adjusted so as to substantially match that of the solid electrolyte 13b. This mixed powder is mixed with a solvent composed of a pore agent, a cellulosic organic binder, and water, extruded, and formed into a hollow plate shape having a gas flow path 12 inside as shown in FIG. Then, a flat insulating support molded body 11 is prepared, dried, and calcined at 900 ° C. to 1100 ° C.

Next, a fuel electrode layer and a solid electrolyte are produced. First, for example, NiO powder, Ni powder, and YSZ powder are mixed, a pore agent is added thereto, an acrylic binder and toluene are mixed to form a slurry, and the slurry is applied by a doctor blade method and dried. Then, an active fuel electrode layer tape 13a having a thickness of 50 to 60 μm is produced (FIG. 7A).
Next, in the same manner as the active fuel electrode layer tape 13a, for example, NiO powder, Ni powder, and rare earth element oxide such as Y ₂ O ₃ are mixed, and a pore agent is added thereto, and an acrylic binder is added. Toluene is mixed to form a slurry, and the slurry is applied by a doctor blade method and dried to produce a current collecting fuel electrode layer tape 23 having a thickness of 50 to 60 μm. The active fuel electrode layer tape 13a is affixed to the current collecting fuel electrode layer tape 23 (FIG. 7B). The bonded tape is cut in accordance with the shape of the power generating element 13, and a portion for forming an insulating portion is punched out (FIG. 7C).

Thereafter, as shown in FIG. 7D, the current collecting fuel electrode layer tape 23 to which the active fuel electrode layer tape 13a is attached is attached to the calcined insulating support molded body 11 in a horizontal stripe shape. This is repeated and a plurality of current collecting fuel electrode layer tapes 23 are attached to the surface of the insulating support body molded body 11. At this time, one current collecting fuel electrode layer tape 23 and the other current collecting fuel electrode layer tape 23 are arranged with an interval of 3 to 20 mm in width. At the tip of one cell, the current collecting fuel electrode layer tape 23 to which the active fuel electrode layer tape 13a is attached is used as the connecting member 30 between the opposing surfaces, and is attached around the surface of the insulating support 11 with a width of 10 mm. wear.
Next, the active fuel electrode layer tape 13a and the current collecting fuel electrode layer tape 23 are dried and then calcined in a temperature range of 900 to 1100 ° C. (FIG. 7D). Then, a masking tape 21 is affixed to a portion of the active fuel electrode layer 13a where the first current collecting layer 17a is to be formed (FIG. 7 (e)).

Next, this laminate is immersed in a solid electrolyte solution that is a slurry obtained by adding an acrylic binder and toluene to 8YSZ, and is taken out from the solid electrolyte solution. By this dipping, a layer of the solid electrolyte 13b is applied to the entire surface, and the space cut out in FIG. 7C is filled with the solid electrolyte 13b as an insulator.
In this state, calcination is performed at 1150 to 1200 ° C. for 2 to 4 hours. During this calcination, the layer of the masking tape 21 and the solid electrolyte 13b applied thereon can be removed (FIG. 7 (f)).

Next, a slurry obtained by mixing lanthanum cobaltite (LaCoO ₃ ) and isopropyl alcohol is printed to form an air electrode layer 13c having a thickness of 10 to 100 μm. Then, baking is performed at 950 to 1150 ° C. for 2 to 5 hours (FIG. 7G).
And the sheet | seat of the metal layer which consists of Ag / Ni is affixed on the part which wants to form the 1st current collection layer 17a, Furthermore, the sheet | seat of the metal glass layer containing Ag and glass is affixed (FIG.7 (g)), and then , Heat treatment is performed at 1000 to 1200 ° C.
Finally, the second current collecting layer 17b can be applied at a predetermined position to obtain a horizontally striped fuel cell (FIG. 7 (i)).

  In addition, about the lamination | stacking method of each above-mentioned layer, you may use any lamination method of tape lamination | stacking, paste printing, dip, and spray spraying. Preferably, the drying process at the time of lamination is short, and each layer is laminated by dipping from the viewpoint of shortening the process.

<Other embodiments>
As shown in FIG. 8, when electrically connecting the cell surface 1a and the cell back surface 1b at the cell tip, the inter-facing surface connection member 30 extends from one surface of the insulating support 11 to the other surface facing it. The insulating support 11 is formed so as to penetrate through the insulating support 11, whereby the fuel electrode layers 13a and 23 of the power generating element 13 at the foremost portion of the cell surface 1a and the first current collecting layer 17a on the cell back surface 1b facing this are connected. Are electrically connected. The first current collecting layer 17a on the cell back surface 1b is electrically connected to the air electrode 13c at the tip of the cell surface on the same side via the second current collecting layer 17b of the inter-element connection member 17 on the cell surface on the same side. Connected.
There are no particular limitations on the shape and the number of the opposing inter-surface connection members 30 that penetrate therethrough as long as electrical connection is ensured and the strength of the support 11 is not impaired. The shape is preferably cylindrical.
Thereby, the connection member 30 between opposing surfaces is protected by the insulation support body 11 and the solid electrolyte 13b, and can prevent the risk of electric leakage and disconnection due to contact with the outside.

  At the time of manufacture, a through hole is previously formed by a drill or the like at a position where the inter-facing surface connection member 30 is disposed at the distal end portion of the insulating support 11. Then, before the step of attaching the current collecting fuel electrode layer tape 23, the opposing surface connecting member 30 can be formed by filling the through hole with, for example, the same material as the current collecting fuel electrode layer 23. .

<Still another embodiment>
As shown in FIG. 9 (a), when electrically connecting the power generating element 13 on the cell front surface 1a and the cell back surface 1b at the cell tip, the inter-facing surface connection member 30 is insulated and supported from the side surface of the power generating element 13. It is formed to the side of the power generation element on the cell back surface 1b through the side surface of the body 11, and the inter-facing surface connection member 30 is formed around the surface of the insulating support 11 and is on the opposite side (cell back surface 1b). The inter-element connection member 17 is connected to and electrically connected to the first current collecting layer 17a. At this time, the inter-facing surface connection member 30 is insulated from the fuel electrode layers 13a and 23 of the power generating element 13 on the opposite side (for example, the cell back surface 1b) by an electrolyte material.
Thereby, the connection member 30 between opposing surfaces is protected by the solid electrolyte 13b, and the risk of electric leakage and disconnection due to contact with the outside can be prevented. FIG. 9B shows the cell surface 1a and the cell back surface 1b of the cell of FIG. 9A.

  At the time of manufacture, in the manufacturing method of the above-described embodiment, the current collector electrode layer tape 23 having the active fuel electrode layer tape 13a attached to the cell tip is used as the inter-face connection member 30, and the support 11 When affixing around the surface, the winding is performed with an interval so as not to contact the active fuel electrode layer 13a and the collector fuel electrode layer tape 23 of the power generation element 13 on the opposite side (for example, the cell back surface 1b). A solid electrolyte material is applied and insulated in the gap formed between the power generating element 13 and the inter-facing surface connecting member 30. At this time, a masking tape is attached to the wound end so that the connecting member 30 between the opposing surfaces can be connected to the first current collector layer 17a of the connecting member 17 formed on the upper surface. And after apply | coating the solid electrolyte 13b, a masking tape is peeled off and it can fill with the same material as the connection member 30 between opposing surfaces, and the connection member 30 between opposing surfaces can be pulled out on the surface of the solid electrolyte 13b.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above example, the insulating support 11 is described as a hollow plate having a plurality of gas flow paths 12 inside, but the insulating support 11 may be cylindrical and the number of gas flow paths 12 There may be only one, and any material may be used as long as it is an insulator. In addition, various modifications can be made within the scope of the present invention.

It is a partially broken perspective view which shows the structure of the fuel battery cell 1 of this invention. (A) is a top view of FIG. 1, (b) is a bottom view of FIG. (A) is the enlarged view of the AA line cross section of FIG. 2, (b) is the enlarged view of the BB line cross section of FIG. It is CC sectional view taken on the line of Fig.3 (a). It is a schematic block diagram of the fuel cell stack of the present invention. It is a manufacturing-process figure of the insulation support body of this invention. It is a manufacturing-process figure of the fuel battery cell of this invention. It is a cross-sectional view showing the structure of another embodiment according to the present invention. (A) is a cross-sectional view showing the structure of still another embodiment of the present invention, (b-1) is a plan view of (a), and (b-2) is a bottom view of (a). It is a perspective view which shows an example of the connection structure of the conventional connection member between cells. It is an enlarged view of a longitudinal section showing an example of a conventional horizontal stripe type solid electrolyte fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 11 Insulation support body 12 Fuel gas flow path 13 Electric power generation element (13a: Active fuel electrode layer, 13b: Solid electrolyte, 13c: Air electrode layer)
17 Inter-element connection member (17a: first current collecting layer, 17b: second current collecting layer)
30 Connecting member between opposing faces

Claims (5)

  A plurality of power generating elements each having a multilayer structure in which an inner electrode, a solid electrolyte, and an outer electrode are sequentially laminated on both opposing surfaces of an electrically insulating porous support having a gas flow path therein; On each of the opposing surfaces of the support, an inner electrode of one of the power generation elements is electrically connected to an outer electrode of the other power generation element adjacent to the one power generation element, and the plurality of power generation elements In a horizontal stripe fuel cell in which elements are connected in series, power generating elements on both surfaces of the porous support facing each other at the cell tip are disposed on the surface and / or inside the porous support. A horizontally-striped fuel cell, wherein the fuel cell is electrically connected by a connecting member between opposing surfaces.   2. The horizontal stripe fuel cell according to claim 1, wherein the connection member between the opposing surfaces is disposed over the entire circumference between the porous support and the solid electrolyte.   2. The horizontal stripe fuel cell according to claim 1, wherein the connecting member between the opposing surfaces is configured to penetrate the porous support from one surface to the other surface facing the one.   The horizontal stripe fuel cell according to any one of claims 1 to 3, wherein the facing inter-surface connection member is made of an electrode material or a metal.   A fuel cell comprising a plurality of horizontally-striped fuel cells according to any one of claims 1 to 4 housed in a housing container.

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