JP2008282653A - Lateral stripe type cell for fuel cell and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lateral stripe type cell for a fuel cell having high output and high reliability, reducing complicated steps by separating stacking portions of a power generation element and a current collector. <P>SOLUTION: Two or more power generation elements 13 each formed by stacking an inside electrode 13a, a solid electrolyte 13b, and an outside electrode 13c in order are arranged in parallel on the surface of an electrically insulating porous supporting substrate 11 having a gas passage on the inside, and the inside electrode of the power generation element 13 is electrically connected to the outside electrode 13c of other power generation element 13 adjoined to the power generation element 13 through a current collector 17 to form the lateral stripe type cell 1 for the fuel cell. The current collector 17 is installed on the side surface of the porous supporting substrate 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

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. On the surface of a cylindrical support 11 (hereinafter referred to as an insulation support) 11 that is a porous insulator, a fuel electrode 3a, a solid electrolyte 3b, and air are provided. A plurality of power generating elements 3 having a multilayer structure in which poles 3c are sequentially stacked are formed at predetermined intervals in the longitudinal 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 the power generation element 3 and the air electrode 3 c of another power generation element 3 adjacent thereto 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.

そして、燃料極３ａと空気極３ｃとを電気的に接続することにより、燃料極３ａから空気極３ｃへの電子の移動が起こり、両極間で起電力が生じる。
このように、固体電解質形燃料電池セルでは、酸素と水素を供給することにより、前記の反応を連続して起こし、起電力を生じさせて発電する（例えば、特許文献１参照）。
横縞型の燃料電池セルでは、以上の反応を起こす発電素子３が、絶縁支持体１１表面に、長手方向に直列に複数接続されているために、少ないセル数で高い電圧が得られるという利点がある。

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).
The horizontal stripe fuel cell has the advantage that a high voltage can be obtained with a small number of cells because a plurality of power generating elements 3 that cause the above reaction are connected to the surface of the insulating support 11 in series in the longitudinal direction. is there.

In the horizontally striped hollow flat solid electrolyte fuel cell in which the power generation elements 3 are formed on both surfaces of the insulating support 11, when the power generation elements 3 on the front and back surfaces of the insulating support 11 are connected in series, As shown in FIG. 10, the metal that circulates outside the cell is connected to the power generating element (not shown) at the front end of the insulating support and the power generating element (not shown) at the front end of the insulating support. A method using band B is known (see, for example, 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, in order to reduce the size of a fuel cell composed of a plurality of power generation elements and a unit composed of a plurality of fuel cells, it is necessary to increase the output of a single cell. One method for achieving higher output is to increase the density of the number of power generation elements (number of power generation elements per unit cell length).
However, in the conventional cell, a power generating element and a current collector composed of a fuel electrode, an electrolyte, an air electrode, and the like are alternately arranged on the surface of the insulating support 11 in the longitudinal direction of the insulating support 11. It was difficult to increase the density of the number of power generation elements. Further, as shown in FIG. 11, there is a problem that a complicated step is formed on the cell surface by the power generation element 3 and the interconnector 4, which causes a gas leak and decreases reliability.
An object of the present invention is to provide a horizontal stripe fuel cell having high output and high reliability by increasing the density of the number of power generation elements and reducing a complicated step formed by the power generation elements and the current collector. It is in.

  As a result of intensive studies to solve the above problems, the present inventor formed the power generating element on the surface of the insulating support substrate and the current collector on the side surface of the insulating support substrate, respectively. The current collector can be laminated as a laminated member having the same polarity on the surface and side surfaces of the insulating support substrate. As a result, the number of power generating elements on the surface of the insulating support substrate can be increased, so that high output can be realized and a plurality of steps on the surface of the insulating support substrate do not occur, so that the occurrence of gas leak can be greatly reduced. . Further, since the adjacent power generating elements on the surface of the insulating support substrate are of the same polarity, the present inventors have found that there is no risk of an electrical short even if the width of the insulating portion between adjacent power generating elements is narrow. It came to complete.

That is, the horizontal stripe fuel cell according to the present invention and the fuel cell using the same have the following configuration.
(1) A plurality of power generation elements in which an inner electrode, a solid electrolyte, and an outer electrode are sequentially stacked are arranged in parallel on the surface of an electrically insulating porous support substrate having a gas flow path therein, and the inner electrode of the power generation element And a laterally striped fuel cell in which the outer electrode of another power generation element adjacent to the power generation element is electrically connected via a current collector, the current collector of the porous support substrate A horizontally-striped fuel cell characterized by being formed on a side surface.
(2) A plurality of the power generation elements are arranged in parallel on the front and back surfaces of the porous support substrate, respectively, and the current collectors are formed on both side surfaces of the porous support substrate, respectively (1) ) Horizontal stripe fuel cell.
(3) The inner electrode of the power generation element is extended to the side surface of the porous support substrate at the site where the power generation element is provided, and the current collector is formed on the surface of the extended portion of the extended inner electrode. The horizontal stripe fuel cell according to (1) or (2), wherein the current collector and an outer electrode of another power generation element adjacent to the power generation element are electrically connected.
(4) The inner electrode of the power generation element is extended to the side surface of the porous support substrate at a portion where the other power generation element adjacent to the power generation element is provided. A horizontal stripe fuel cell according to (1) or (2), wherein a current collector is formed, and the current collector is electrically connected to an outer electrode of the other power generating element. .
(5) In any one of (2) to (4), the surface of the current collector and the surface of the outer electrode of the other power generation element are connected via an inter-element connection member. The horizontal stripe fuel cell as described.
(6) A fuel cell comprising a plurality of horizontally-striped fuel cells according to any one of (1) to (5) stored in a storage container.

In the horizontal stripe fuel cell of the present invention, the current collector, which has been arranged alternately in parallel with the power generation element on the surface of the insulating support substrate, is provided on the side surface of the insulating support substrate. Even so, more power generating elements can be provided. Therefore, it becomes possible to increase the output of the cell (the cell can be made smaller if the output is the same). In addition, since members having the same polarity are disposed on the same surface and side surfaces of the insulating support substrate, there is no risk of causing an electrical short even if the width of the insulating portion between adjacent power generation elements is narrow. In addition, since only power generating elements having the same polarity are stacked on the same surface of the insulating support substrate, a complicated step caused by the parallel arrangement of current collectors of opposite poles as in the prior art does not occur. Thereby, the gas leak defect from a level | step-difference part can be reduced. From the above, it is possible to provide a horizontal stripe fuel cell having high output and high reliability.
According to the fuel cell of the present invention, it is possible to reduce the capacity by using a plurality of horizontally striped fuel cells with high output, and a high power generation amount can be obtained with a small number of horizontally striped 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 horizontal stripe fuel cell according to the present invention, and FIG. 2 is a plan view of FIG. In the fuel cell 1, a porous support (hereinafter referred to as a porous support substrate 11) includes a gas flow path 12 inside, and power generation elements 13 are formed on the front and back surfaces of the porous support substrate 11, and both side surfaces are provided. And a current collector 17 is formed. That is, the current collecting fuel electrode layer 23, the active fuel electrode layer 13a, the solid electrolyte layer 13b, and the air electrode layer 13c are sequentially laminated on the front and back surfaces of the electrically insulating porous support substrate 11 having a hollow flat plate shape. The current generating element 13 is arranged, and the current collector 17 constituting the same element portion together with the power generating element 13 is adjacent to the active fuel electrode layer 13a on each of both side surfaces (both ends in the width direction) of the porous support substrate 11. Are arranged. At this time, the current collecting fuel electrode layer 23 constituting the same element portion extends to the side surface adjacent to the width direction of the porous support substrate 11, and the extended portion 23 ′ of the current collecting fuel electrode layer 23 extended. The current collector 17 is formed on the surface.
A plurality of the element portions including the current collector 17 are arranged at predetermined intervals in the longitudinal direction of the porous support substrate 11, and they are connected in series via the inter-element connection member 18, thereby forming a horizontal stripe type. A fuel cell 1 was constructed.
The element portion includes the power generation element 13 and the current collector 17, and the power generation element 13 disposed on the surface of the porous support substrate 11 and the porous support substrate 11 on the width direction side of the power generation element 13. The current collectors 17 arranged on the side surfaces of the same are called the same element portion. In addition, the surface as used in this application means the main surface with a larger area than the side surface provided in the position which opposes, and may be used including a surface and a back surface.

  In the present invention, as described above, the current collector 17 that has been conventionally disposed adjacent to the power generation element 13 in the longitudinal direction on the surface of the porous support substrate 11 is disposed on the side surface of the porous support substrate 11, Both the surface and the side surface of the porous support substrate 11 were utilized for the arrangement of the element portion. Thereby, since more element parts can be arranged in the longitudinal direction of the porous support substrate 11, the amount of power generation per unit area can be increased, and high output or miniaturization can be achieved. In addition, since only a plurality of members of the same polarity are disposed adjacent to each other on the surface and side surfaces of the porous support substrate 11, even if the width of the insulating portion between adjacent element portions is narrow, an electrical short The risk of causing

  Conventionally, the power generation element 13 and the current collector 17 are alternately arranged in the longitudinal direction on the surface of the porous support substrate 11, so that a complicated step is generated in the element portion, and gas leakage occurs due to the influence of the step. It was. However, by arranging the current collector 17 on the side surface of the porous support substrate 11, the element portion has a certain level difference (see FIG. 3), and gas leak defects can be reduced.

  The solid electrolyte 13b has both the function of an insulating layer for electrically blocking between adjacent element portions and the function of preventing gas leakage from the gas flow path 12, so that the surface and side surfaces of the porous support substrate 11 are It is formed so as to cover the exposed part. On the other hand, since the solid electrolyte 13b is conventionally laminated on the entire surface of the porous support substrate 11, there is a problem that the solid electrolyte 13b is easily peeled off at both ends in the width direction of the porous support substrate 11 having a curvature. In the present invention, since the side surface of the porous support substrate 11 can be made flat, it is possible to suppress the separation of the solid electrolyte 13b.

In the present embodiment, as shown in FIG. 2, the inter-element connection member 18 for connecting adjacent element parts is a current collector 17 of another element part adjacent to the surface of the air electrode layer 13c of the element part. It is formed so as to connect with the surface. The arrow in the figure indicates the direction of movement of electricity (electron e ⁻ ). That is, the electrons generated in the power generation element 13 are collected on the side surface through the extending portion 23 ′ of the current collecting fuel electrode layer 23 extending from the active fuel electrode 13 a to the side surface of the porous support substrate 11. It moves to the body 17 and is then sent to the air electrode 13 c of another adjacent power generation element 13 via the inter-element connection member 18 connected to the surface of the current collector 17. As a result, the power generating elements 13 are electrically connected in series.

  The porous support substrate 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 longitudinal direction. Is provided. The number of the gas flow paths 12 is preferably 2 to 20, for example, and more preferably 6 to 15 in terms of power generation performance and structural strength. In this way, by forming a plurality of gas flow paths 12 inside the porous support substrate 11, the porous support substrate 11 can be compared with the case where one large gas flow path is formed inside the porous support substrate 11. Can be made into a flat plate shape, and the area of the power generation element 13 per volume of the fuel cell 1 can be increased to increase the amount of power generation. 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.

  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. 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. 3, the fuel cells 1 are electrically connected to each other via an inter-cell connecting member 19 disposed at the lower end.
That is, at the lower end portion of the cell stack, an inter-element connection member 18 is provided at the lower end portion of the fuel cell 1, and the other element portions adjacent to each other through the current collector 17 connected to the inter-element connection member 18 are provided. The collector fuel electrode layer 23 is electrically connected. The inter-element connection member 18 is electrically connected to the air electrode layer 13 c of the other fuel battery cell 1 via the inter-cell connection member 19 via the inter-element connection member 18. On the other hand, at the cell tip portion, the current collecting fuel electrode layer 23 on the surface of the porous support substrate 11 and the air electrode layer 13c on the other surface (back surface) facing each other through the current collector 17 and the inter-element connection member 18. Connected.
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.
(Porous support substrate)
The porous support substrate 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 . Preferably, the composition is 10 to 25 mol% NiO, 60 to 80 mol% MgO, and 5 to 15 mol% Y ₂ O ₃ .

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

The porous support substrate 11 needs to be electrically insulative in order to prevent an electrical short circuit between the power generating elements 13, and normally 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 porous support substrate 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%.
Moreover, the porous support substrate 11 is set to have a thickness of 2 to 5 mm, a width of 30 to 50 mm, and a length of 200 to 300 mm, for example, from the viewpoint of obtaining good power generation performance and structural strength. Is desirable. The present invention is not limited to this dimension.

(Fuel electrode layer)
The fuel electrode layer causes the electrode reaction of the above formula (2), and in this embodiment, the active fuel electrode layer 13a on the solid electrolyte 13b side and the current collecting fuel electrode layer on the porous support substrate 11 side. 23 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.
Among the fuel electrode layers, the current collecting fuel electrode layer 23 on the porous support substrate 11 side is a mixture of Ni or Ni oxide and rare earth element oxide, like the porous support substrate 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 porous support substrate 11 and the current collecting fuel electrode layer 23 can be made 2 × 10 ⁻⁶ (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 with the active fuel electrode layer 13a on the solid electrolyte 13b side and the current collecting fuel electrode layer 23 on the porous support substrate 11 side, the porous support substrate 11 side is provided. By adjusting the Ni amount or NiO amount in terms of NiO of the current collecting fuel electrode layer 23 within the range of 30 to 60% by volume, the thermal expansion coefficient is reduced without impairing the bonding property with the power generation element 13. The thermal expansion coefficient of the solid electrolyte 13b, which will be described later, can be approached. 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. . For this reason, even when fuel gas (hydrogen gas) is flowed to generate power, the consistency of the thermal expansion coefficient with the porous support substrate 11 is maintained stably, and cracks due to thermal expansion differences can be effectively avoided. it can.

(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.

(Current collector)
A current collector 17 used for connecting adjacent power generating elements 13 in series connects an active fuel electrode layer 13a of the power generating element 13 and an air electrode layer 13c of another power generating element 13. These can be made of conductive ceramics, metal, or metal glass containing glass. As the conductive ceramic, lanthanum chromite perovskite oxide (LaCrO ₃ oxide) is used. Alternatively, a two-layer structure of a metal layer and a metal glass layer containing glass may be used. 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.
Further, the current collector 17 can have a good current collecting property if its thickness is 20 μm or more.

(Element connection member)
The inter-element connection member 18 used for connecting adjacent power generating elements 13 in series connects the current collector 17 of the element section and the air electrode layer 13c of another adjacent element section. As the inter-element connection member 18, conductive glass, metal, or metal glass containing glass can be used. As the conductive ceramic, those used for the air electrode layer 13 c can be used. Moreover, in order to supply oxygen-containing gas, such as air, to the air electrode layer 13c, the conductive ceramic is made porous.
Moreover, as the inter-element connection member 18, a porous layer made of, for example, Ag—Pd can be used.
Further, the inter-element connection member 18 can have good conductivity if the thickness is 100 μm or more.

  In the example described above, the power generating element 13 formed on the porous support substrate 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, an air electrode layer, a solid electrolyte, and an active fuel electrode layer can be laminated in this order on the porous support substrate 11 to form a power generation element. In this case, an oxygen-containing gas such as air is introduced into the gas flow path of the porous support substrate 11, and the fuel gas is supplied to the outer surface of the active fuel electrode layer that is the outer electrode.

(Cell connecting member)
The inter-cell connecting member 19 is electrically connected to the air electrode layer 13 c of another fuel cell 1 facing the fuel cell 1, and the inter-element connecting member 18 of the fuel cell 1 and the air of the other fuel cell 1. The electrode layer 13c is not particularly limited as long as it is electrically connected to the electrode layer 13c. For example, the electrode layer 13c is formed of a heat-resistant metal, a conductive ceramic, or the like.
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 18 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 porous support substrate molded body 61 is produced. As a material of the porous support substrate molded body 61, for example, it is necessary for an MgO powder having an average particle diameter (D ₅₀ ) (hereinafter simply referred to as “average particle diameter”) on a volume basis of 0.1 to 10.0 μm. After mixing, Ni powder, NiO powder, Y ₂ O ₃ powder, rare earth element stabilized zirconia powder (YSZ), etc. are blended at a predetermined ratio for adjusting the thermal expansion coefficient or improving the bonding strength. The thermal expansion 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 as shown in FIG. 4, for example, a gas having a diameter of 1.0 to 1.5 mm inside. A hollow plate-like shape having six channels 62, having a length of 250 to 300 mm, a width of 60 to 70 mm, and a flat porous support substrate molded body 61 having a thickness of 3 to 5 mm, was dried, Calcination is performed at 900 ° C to 1200 ° 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, and an acrylic binder and toluene are mixed to prepare an active fuel electrode paste. Next, for example, NiO powder, Ni powder, and a rare earth element oxide such as Y ₂ O ₃ are mixed, a pore agent is added thereto, an acrylic binder and toluene are mixed to form a slurry, and a doctor blade The slurry is applied by the method and dried to produce a current collecting fuel electrode layer tape 63 having a thickness of 80 to 120 μm. Next, as shown in FIG. 5, for example, an active fuel electrode paste layer 63 a having a thickness of 30 to 60 μm and a collector film having a thickness of 30 to 60 μm are collected on the current collecting fuel electrode layer tape 63 using a predetermined mesh plate making. The electrical paste layer 67 is formed by printing. The bonded tape is cut in accordance with the shape S of the power generating element 13, and a portion R that forms an insulating portion is punched out [a chain line portion in FIG. However, in FIG. 5, the hatching 63a and 67 means not a cross section but a region. ]

Thereafter, the current collector fuel electrode layer tape 63 on which the active fuel electrode paste layer 63a and the current collector paste layer 67 are printed is respectively applied to the corresponding portions (A, B, C) of the calcined porous support substrate molded body 61. And D). That is, corresponding portions A and C of the active fuel electrode paste layer 63a are formed on the front and back surfaces (A, C) of the calcined porous support substrate molded body 61 on both sides of the calcined porous support substrate molded body 61. Affixed so that the corresponding parts B and D of the current collector paste layer 67 are laminated on the surfaces (B and D) [see FIG. However, in FIG. 8, the hatching 63a and 67 means a region, not a cross section. ]. In this manner, the plurality of element portions are attached in a horizontal stripe shape while sequentially providing the insulating portions between the element portions. This is repeated, and the current collector fuel electrode layer tape 63 in which a plurality of active fuel electrode paste layers 63a and current collector paste layers 67 are respectively printed and laminated is attached to the front and back surfaces of the porous support substrate molded body 61.
FIG. 8 shows a state where the current collecting fuel electrode layer tape 63 for lamination after printing is attached to the surface of the porous support substrate molded body 61 in comparison with the conventional structure.
Next, it dries in the state which affixed the current collection fuel electrode layer tape 63 which laminated | stacked this active fuel electrode paste layer 63a and the current collector paste layer 67, and calcined in the temperature range of 900-1100 degreeC after that.

Next, the solid electrolyte solution made into a slurry by adding acrylic binder and toluene to 8YSZ was printed on the front and back surfaces of this laminate and both sides of the surface of the current collector paste layer 67 masked. Peel off. By this printing, for example, a layer of a solid electrolyte slurry having a thickness of 30 to 60 μm is applied to the entire front and back surfaces of the laminate, and the solid electrolyte slurry is also filled in the insulating portion between adjacent element portions. The
In this state, firing is performed at 1450 to 1500 ° C. for 2 to 4 hours.

Next, a slurry in which lanthanum cobaltite (LaCoO ₃ ) and isopropyl alcohol are mixed is printed on the front and back surfaces of the obtained laminate 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.
Finally, a paste to be an inter-element connection member 18 having a thickness of 150 to 400 μm, for example, is applied to the surface of the current collector 17 and the air electrode layer 13c, and the inter-element connection member 18 is connected between the both surfaces. The horizontal stripe fuel cell can be obtained.

  In addition, about the lamination | stacking method of each above-mentioned layer, you may use any lamination method of tape lamination | stacking, paste printing, dipping, and spray spraying.

(Other embodiments)
In another embodiment according to the present invention, as shown in FIGS. 6A and 6B, the inter-element connection member 18 for connecting adjacent power generating elements is the surface of the air electrode layer 13c of the element portion. And the current collector 17 surface of the element part. At this time, as shown in FIG. 6A, the current collecting fuel electrode layer 23 of the other power generation element 13 adjacent to the power generation element 13 extends to the side surface of the porous support substrate 11 on the element side. The current collector 17 of the element portion is connected to the extended portion 23 ′ of the extended current collecting fuel electrode layer 23. The arrow in the figure indicates the direction of movement of electricity (electron e ⁻ ). That is, as shown in FIG. 6 (b), the electrons generated in the other power generating element 13 adjacent to each other are collected from the active fuel electrode 13a of the same element part through the current collecting fuel electrode layer 23 and collected in the element part. It moves to the body 17 and then is sent to the air electrode 13 c of the power generating element 13 through the inter-element connection member 18 connected to the surface of the current collector 17. Thereby, the power generation elements 13 are electrically connected in series.
At the time of production, it can be produced by the same production method as in the above-described embodiment except for the steps shown below. As shown in FIG. 7, the active fuel electrode paste layer 63a and the current collector paste layer 67 are formed on the current collecting fuel electrode layer tape 63 by using a predetermined mesh plate as in the case of the embodiment. Then, the bonded tape is cut according to the shape S of the power generating element 13. And the part R which forms an insulation part is punched out so that the other collector 17 in the row | line | column adjacent to the active fuel electrode 13a may be connected [the dashed-dotted line part of FIG. However, in FIG. 7, the hatched lines 63a and 67 indicate regions rather than cross sections. ]

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, as shown in FIG. 9, in order to electrically connect adjacent power generation elements, the above-described embodiment in which an inter-element connection member is extended and connected to the current collector 17 of another power generation element; A configuration in which the current collecting fuel electrode 23 is extended and connected to the current collector 17 of another power generation element may be combined. Although FIG. 9 shows an example in which the power generation element or the like is arranged on one side of the porous support substrate 11, it goes without saying that it may be arranged on both sides.
In the above manufacturing example, the inter-element connection member 18 is applied by applying the same paste to the portion laminated on the surface of the air electrode layer 13c and the portion laminated on the surface of the current collector 17, and then connecting the same. However, it may be connected by an electrically connectable member such as metal. Alternatively, the inter-element connecting member 18 may be affixed integrally including the both surfaces and the connecting portion.
Further, in the above embodiment, the case where the active fuel electrode layer 13a and the current collecting fuel electrode layer 23 are provided has been described, but the same effect can be obtained even when only the active fuel electrode layer 13a is provided.
Moreover, in the said form, although the material, the dimension, etc. were described about the porous support substrate 11, the electrical power collector 17, the element connection member 18, etc., in this invention, it is limited to the material, the dimension, etc. which were described in the said form. It is not something.

It is a partially broken perspective view which shows the structure of the fuel battery cell of this invention. It is a top view of FIG. It is a longitudinal cross-sectional view which shows the cell stack of the horizontal stripe type fuel cell of FIG. It is a manufacturing-process figure of the porous support substrate of this invention. It is a manufacturing-process figure of the fuel battery cell of this invention. (A) is a top view of the fuel cell of other embodiment concerning the present invention, (b) is a BB line sectional view of (a). It is a manufacturing-process figure of the fuel battery cell of other embodiment which concerns on this invention. It is the figure which compared about a part and structure of the manufacturing process of the conventional horizontal stripe type fuel cell (a) and the horizontal stripe type fuel cell (b) of this invention. It is a top view of the fuel cell which combined one embodiment and other embodiments concerning the present invention. It is a perspective view which shows an example of the connection structure of the conventional connection member between cell stacks. 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 Porous support substrate 12 Fuel gas flow path 13 Electric power generation element (13a: Active fuel electrode layer, 13b: Solid electrolyte, 13c: Air electrode layer)
17 Current collector 18 Inter-element connection member

Claims (6)

  A plurality of power generation elements in which an inner electrode, a solid electrolyte, and an outer electrode are sequentially stacked are arranged in parallel on the surface of an electrically insulating porous support substrate having a gas flow path therein, and the inner electrode of the power generation element, A horizontal stripe fuel cell in which an outer electrode of another power generation element adjacent to the power generation element is electrically connected via a current collector, and the current collector is formed on a side surface of the porous support substrate A horizontally-striped fuel cell characterized by being made.   2. The power generation element according to claim 1, wherein a plurality of the power generation elements are arranged side by side on the front and back surfaces of the porous support substrate, and the current collectors are formed on both side surfaces of the porous support substrate. Horizontal stripe fuel cell.   The inner electrode of the power generation element is extended to the side surface of the porous support substrate at the site where the power generation element is provided, and the current collector is formed on the surface of the extended portion of the extended inner electrode, The horizontal stripe fuel cell according to claim 1 or 2, wherein a current collector and an outer electrode of another power generation element adjacent to the power generation element are electrically connected.   An inner electrode of the power generation element extends to a side surface of the porous support substrate at a portion where the other power generation element adjacent to the power generation element is provided, and the current collector is formed on the surface of the extended portion of the extended inner electrode. The horizontal stripe fuel cell according to claim 1, wherein the current collector is electrically connected to an outer electrode of the other power generation element.   The horizontal stripe fuel according to any one of claims 2 to 4, wherein a surface of the current collector and a surface of an outer electrode of the other power generation element are connected via an inter-element connection member. Battery cell.   A fuel cell comprising a plurality of horizontally-striped fuel cells according to claim 1 in a storage container.

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