JP5686190B2 - Joining material for solid oxide fuel cell, method for producing solid oxide fuel cell, method for producing solid oxide fuel cell module, solid oxide fuel cell and solid oxide fuel cell module - Google Patents

Description

  The present invention relates to an electrical connecting material for a solid oxide fuel cell, a joining material for a solid oxide fuel cell, a method for producing a solid oxide fuel cell, a method for producing a solid oxide fuel cell module, and a solid oxide. The present invention relates to a fuel cell and a solid oxide fuel cell module.

  In recent years, attention has been paid to fuel cells as a new energy source. Examples of the fuel cell include a solid oxide fuel cell (SOFC), a molten carbonate fuel cell, a phosphoric acid fuel cell, and a solid polymer fuel cell. Among these fuel cells, solid oxide fuel cells do not necessarily require liquid components, and can be reformed internally when using hydrocarbon fuel. For this reason, research and development on solid oxide fuel cells are actively conducted.

For example, in Patent Document 1, as an interconnector for a solid oxide fuel cell, a general formula: Ln _1-x Ae _x MO _3-δ (1) (where Ln is at least one selected from lanthanoids) Ae is one or more elements selected from the group consisting of Sr, Ba and Ca, and M is Ti, Zr, Al, Ga, Nb, Ta, Fe, Co, Ni , Cu, Mn, Mg, Rh, Pd, Pt and Au are one or more elements selected from the group consisting of 0 ≦ x ≦ 1, δ is a value determined to satisfy the charge neutrality condition The interconnector is formed from a perovskite oxide represented by the formula (II) and silica, and the content of the silica in the entire interconnector is 5% by mass to 14% by mass. In Patent Document 1, the interconnector has a function of electrically connecting the fuel cells. Patent Document 1 describes that the interconnector described in Patent Document 1 has a dense structure, so that leakage of oxidant gas and fuel gas can be suppressed by using this interconnector. .

JP 2010-186645 A

  However, in the interconnector described in Patent Document 1, electrical connection may not be suitably performed, and the electrical resistance may increase.

  This invention is made | formed in view of such a point, The objective is to provide the electrical connection material for solid oxide fuel cells in which suitable electrical connection is possible.

A bonding material for a solid oxide fuel cell according to the present invention includes a bonding material main body and an electric connection portion that is disposed at a different position in plan view from the bonding material main body and includes a porous metal layer. Prepare. The bonding material main body includes a glass ceramic layer containing silica, barium oxide and alumina, and a constraining layer provided on the glass ceramic layer and containing alumina and glass.

  In a specific aspect of the solid oxide fuel cell bonding material according to the present invention, the porous metal layer is made of a foam metal.

  In another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the porosity of the porous metal layer is 10% by volume to 95% by volume.

  In another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the porous metal layer is a metal selected from the group consisting of silver, gold, palladium, nickel, and stainless steel, or silver, gold, It consists of an alloy containing at least one metal selected from the group consisting of palladium, nickel and stainless steel.

  In another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the constraining layer does not sinter or melt at the sintering temperature of the glass ceramic layer.

  In yet another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the solid oxide fuel cell bonding material is provided between the bonding material main body and the electrical connection portion, An adhesive portion made of glass ceramics is further provided.

  In still another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the content of alumina in the constraining layer is 30% by mass to 90% by mass.

  In still another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the constraining layer is made of a metal plate in which a plurality of through holes penetrating in the thickness direction are formed.

  In another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the constraining layer is made of expanded metal, punching metal, wire mesh, or foam metal.

  In still another specific aspect of the solid oxide fuel cell bonding material according to the present invention, the constraining layer has a melting point of 900 ° C. or higher.

In the production method of engaging Ru solid body oxide fuel cell in the present invention, electrically connected with joining a plurality of power generation cells with solid oxide fuel cell bonding material according to the present invention.

In the manufacturing method of the solid body oxide fuel cell module engaging Ru in the present invention, joined with the power generation cell, and other power generation cell or enclosure using a solid oxide fuel cell bonding material according to the present invention And connect electrically.

Solid body oxide fuel cell Ru engaged to the present invention includes a bonding layer, and a plurality of power generation cells. The bonding layer is made of a sintered body of the solid oxide fuel cell bonding material according to the present invention. The plurality of power generation cells are joined and electrically connected by a joining layer.

The first solid oxide fuel cell module according to the present invention is provided with the engaging Ru solid body oxide fuel cell to the present invention.

The second solid oxide fuel cell module according to the present invention includes a bonding layer, a fuel cell, and a housing. The bonding layer is made of a sintered body of the solid oxide fuel cell bonding material according to the present invention. The housing is joined to and electrically connected to the fuel cell by the joining layer.

  ADVANTAGE OF THE INVENTION According to this invention, the electrical connection material for solid oxide fuel cells in which suitable electrical connection is possible can be provided.

FIG. 1 is a schematic perspective view of a solid oxide fuel cell bonding material according to a first embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. FIG. 3 is a schematic perspective view of the solid oxide fuel cell bonding material according to the second embodiment. FIG. 4 is a schematic perspective view of a solid oxide fuel cell bonding material according to a third embodiment. FIG. 5 is a schematic cross-sectional view of a joining material body of a joining material for a solid oxide fuel cell according to a fourth embodiment. FIG. 6 is a schematic cross-sectional view of a bonding material body of a solid oxide fuel cell bonding material according to a fifth embodiment. FIG. 7 is a schematic cross-sectional view of a bonding material body of a bonding material for a solid oxide fuel cell according to a sixth embodiment. FIG. 8 is a schematic cross-sectional view of a joining material body of a joining material for a solid oxide fuel cell according to a seventh embodiment. FIG. 9 is a schematic cross-sectional view of an electrical connection portion of the solid oxide fuel cell bonding material according to the eighth embodiment. FIG. 10 is a schematic side view of a solid oxide fuel cell module according to the ninth embodiment. FIG. 11 is a schematic exploded perspective view of the power generation cell according to the ninth embodiment. FIG. 12 is a schematic exploded perspective view of a fuel cell according to the ninth embodiment. FIG. 13 is a schematic exploded perspective view of a part of the fuel cell module according to the ninth embodiment.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described, and the ratio of the dimensions of the objects drawn in the drawings may be different from the ratio of the dimensions of the actual objects. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

<< First Embodiment >>
FIG. 1 is a schematic perspective view of a solid oxide fuel cell bonding material according to a first embodiment. FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG.

  The solid oxide fuel cell bonding material 1 is a bonding material used for a solid oxide fuel cell module. Specifically, it can be used for, for example, applications in which the power generation cells are joined and electrically connected, and applications in which the power generation cell of the fuel cell and the housing are joined and electrically connected.

  The solid oxide fuel cell bonding material 1 includes a bonding material body 2 and an electrical connection portion 3 as an electrical connection material.

(Bonding material body 2)
The joining material main body 2 mainly bears the function of joining the members to be joined together. For this reason, the joining material main body 2 is not particularly limited as long as the members to be joined can be suitably joined to each other. The joining material main body 2 can also be comprised, for example with glass ceramics. In the present embodiment, an example in which the bonding material body 2 is configured by a laminated body of a glass ceramic layer 10 and a constraining layer 11 provided on the glass ceramic layer 10 will be described. Note that it is not always necessary to provide both the glass ceramic layer 10 and the constraining layer 11. One of the glass ceramic layer 10 and the constraining layer 11 may be provided.

  The glass ceramic layer 10 contains glass ceramics. The glass ceramic layer 10 may be made of only glass ceramics, or may contain, for example, amorphous glass in addition to the glass ceramics.

  Here, the “glass ceramics” is a mixed material system of glass and ceramics.

In the present embodiment, the glass ceramic contains silica, barium oxide, and alumina. In the glass ceramics, Si is 48 mass% to 75 mass% in terms of SiO ₂ , Ba is 20 mass% to 40 mass% in terms of BaO, and Al is 5 mass% to 20 mass% in terms of Al ₂ O _3. It is preferable that it is included. Glass ceramics, further, in terms of 2 mass% to 10 mass% in terms of Mn to MnO, 0.1 wt% to 10 wt% in terms of Ti to TiO _2, and Fe in the _Fe 2 _{O 3} You may further contain 0.1 mass%-10 mass%. It is preferable that the glass ceramic does not substantially contain Cr oxide or B oxide. In this case, for example, glass ceramics that can be fired at a temperature of 1100 ° C. or lower can be obtained.

  Although the thickness of the glass ceramic layer 10 is not specifically limited, For example, it is preferable that they are 10 micrometers-150 micrometers, and it is more preferable that they are 20 micrometers-50 micrometers.

  A constraining layer 11 is stacked on the glass ceramic layer 10. In the present embodiment, the constraining layer 11 and the glass ceramic layer 10 are in direct contact.

  The constraining layer 11 is not fired or melted at the firing temperature of the glass ceramic layer 10. That is, the constraining layer 11 has such a property that the glass ceramic layer 10 can be fired in a state where the constraining layer 11 is not substantially fired or melted. The constraining layer 11 is preferably made of a metal plate or ceramic.

  For example, the constraining layer 11 preferably contains an inorganic material such as alumina that does not sinter at the sintering temperature of glass ceramics. In this case, the glass ceramic layer 10 can be sintered in a state where the constraining layer 11 does not substantially contract. Moreover, it is preferable that the constrained layer 11 contains glass. In this case, when the bonding material 1 is sintered, the bonding strength between the constraining layer 11 and the layer formed by sintering the glass ceramic layer 10 can be increased. In addition, it is preferable that the center particle diameter of an inorganic material is 5 micrometers or less. When the center particle diameter of the inorganic material is larger than 5 μm, the effect of suppressing shrinkage during firing of the glass ceramic layer may be reduced.

  In the constraining layer 11, the glass volume is preferably 10 to 70% with respect to the total volume of alumina and glass. If the volume of the glass is less than 10%, the amount of glass in the constraining layer may be insufficient, and these may not be densified. When the volume of the glass exceeds 70%, the shrinkage suppressing effect at the time of firing the glass ceramic layer may be weakened. The glass contained in the constraining layer 11 may be an amorphous glass or a glass that crystallizes at least partially during firing.

  Moreover, the constraining layer 11 may be configured by a metal plate in which a plurality of through holes penetrating in the thickness direction (z direction) are formed. Specifically, the constraining layer 11 may be made of expanded metal, punching metal, wire mesh, foam metal, or the like.

  Here, “expanded metal” refers to a group of cuts having a plurality of linear cuts extending in one direction and arranged at intervals along one direction, and perpendicular to the one direction. A plurality of metal plates that are arranged at intervals along the other direction, and the cuts are staggered along the other direction, are formed by extending in the other direction. A metal plate having openings formed in an oblique matrix.

  The expanded metal preferably has a porosity of 30% to 86%, a line width of 30 μm to 250 μm, and a thickness of 30 μm to 500 μm.

  “Punching metal” refers to a metal plate having a plurality of openings formed in a matrix at predetermined intervals.

  The punching metal preferably has a porosity of 10% to 60%, an opening diameter of 50 μm to 1000 μm, and a thickness of 30 μm to 250 μm.

  The “wire mesh” is a plurality of first metal lines that extend in one direction and are spaced apart from each other along another direction perpendicular to the one direction, and extend in the other direction. A plurality of second metal lines that are arranged at intervals along one direction and intersect with the plurality of first metal lines, and the plurality of first metal lines and the plurality of first metal lines The second metal wire is a member fixed in the thickness direction perpendicular to one direction and the other direction. In the “wire mesh”, a member in which a plurality of first metal wires and a plurality of second metal wires are knitted, a plurality of first metal wires, and a plurality of second metal wires are welded, etc. And both non-knitted members are included.

  The metal mesh preferably has a porosity of 50% to 85% and a wire diameter of 50 μm to 200 μm.

  “Foamed metal” refers to a metal member having a plurality of pores therein. The foam metal may have a three-dimensional network structure. The pores may be continuous pores or closed pores.

  The foam metal preferably has a porosity of 10% to 70%.

  When the constraining layer 11 is formed of a metal plate having a plurality of through holes, the constraining layer 11 preferably has a melting point of 900 ° C. or higher and does not melt at the firing temperature of the glass ceramic layer 10. For this reason, it is preferable that the constrained layer 11 consists of high melting point metals, such as stainless steel, silver, gold | metal | money, nickel, for example. The melting point of the constraining layer 11 is more preferably 1100 ° C. or higher.

  The thickness of the constraining layer 11 is preferably 0.5 μm to 500 μm, and more preferably 1 μm to 300 μm. When the thickness of the constraining layer 11 is less than 0.5 μm, the effect of suppressing shrinkage in the surface direction may be reduced. When the thickness of the constraining layer 11 exceeds 500 μm, it is disadvantageous for the reduction in the height of the solid oxide fuel cell.

(Electrical connection 3)
The electrical connection portion 3 is arranged at a different position from the bonding material body 2 in a plan view (when viewed from the thickness direction of the solid oxide fuel cell bonding material 1). Whereas the bonding material body 2 is mainly responsible for the function of bonding the members to be bonded, the electrical connection portion 3 has conductivity and functions to electrically connect the members to be bonded. Is responsible. For this reason, the electrical connection part 3 should just be distribute | arranged so that it may be located between the terminal part of one to-be-joined member, and the terminal part of the other to-be-joined member. That is, the arrangement of the electrical connection portion 3 can be appropriately set according to the arrangement of the terminal portion of one member to be joined and the terminal portion of the other member to be joined. In the present embodiment, the electrical connection portion 3 is provided so as to extend from the center of the solid oxide fuel cell bonding material 1 to one end side of the solid oxide fuel cell bonding material 1.

  The electrical connection portion 3 includes a porous metal layer 3a. Specifically, in this embodiment, the electrical connection part 3 is comprised only by the porous metal layer 3a. The porous metal layer 3a may be made of a foam metal.

  The constituent material of the porous metal layer 3a is not particularly limited as long as it has conductivity. The porous metal layer 3a includes, for example, a metal selected from the group consisting of silver, gold, palladium, nickel and stainless steel, or at least one metal selected from the group consisting of silver, gold, palladium, nickel and stainless steel. It can be composed of an alloy. Especially, it is preferable that the porous metal layer 3a is comprised with silver. In this case, it is easy to deform following the amount of contraction of the bonding material main body 2 and the conductivity is high.

  The porous metal layer 3a may have continuous pores or may have closed pores.

  The porosity of the porous metal layer 3a is preferably 10% by volume to 95% by volume, and more preferably 20% by volume to 60% by volume.

  The thickness of the porous metal layer 3a may be the same as the thickness of the bonding material body 2 or may be different. The thickness of the porous metal layer 3a is preferably 0.5 to 1.5 times the thickness of the bonding material body 2 and more preferably 0.9 to 1.1 times.

  By the way, for example, the amount of shrinkage of the bonding material and the amount of shrinkage of the power generation cell when the bonding material is heated to join the two power generation cells using the bonding material are different. Normally, the bonding material contracts more than the power generation cell. At the time of bonding, stress is applied to the bonding material due to the difference in shrinkage between the bonding material and the power generation cell.

  Therefore, for example, when performing bonding and electrical connection using a conductive paste as described in Patent Document 1 as a bonding material, the bonding layer formed from the conductive paste and the material to be bonded are not suitably bonded, Therefore, there are cases where electrical connection cannot be suitably performed.

  Therefore, the metal member is disposed between the portions to be electrically connected between the two members to be bonded, and the bonding material is disposed in the other portion, thereby performing bonding and electrical connection. It is also possible.

  However, in this case, the bonding material contracts in the thickness direction during heat bonding, but the metal member does not contract in the thickness direction. For this reason, it is controlled that a to-be-joined member approaches by a metal member with the shrinkage | contraction in the thickness direction of a joining material. Therefore, a gap is generated between the bonding material and at least one member to be bonded due to shrinkage in the thickness direction of the bonding material. As a result, the members to be joined cannot be suitably joined.

  On the other hand, in this embodiment, the electrical connection part 3 consists of the porous metal layer 3a. For this reason, when the bonding material main body 2 contracts in the thickness direction during heat bonding, the porous metal layer 3a also contracts in the thickness direction by the amount of contraction in the thickness direction of the bonding material main body 2 accordingly. Therefore, the bonding material main body 2 is not easily separated from the member to be bonded, and the electrical connection portion 3 is also difficult to separate from the member to be bonded. Therefore, by using the solid oxide fuel cell bonding material 1 of the present embodiment, it is possible to suitably perform bonding and electrical connection between the members to be bonded.

  From the viewpoint of more suitably performing joining and electrical connection between the members to be joined, the porosity of the porous metal layer 3a is preferably 10% by volume to 95% by volume, and 20% by volume to 60%. More preferably, it is volume%. If the porosity of the porous metal layer 3a is too low, it may be difficult to shrink in the thickness direction during heat bonding. On the other hand, if the porosity of the porous metal layer 3a is too high, the porous metal layer 3a may shrink too much in the thickness direction during heat bonding.

  The thickness of the porous metal layer 3a is preferably 0.5 to 1.5 times the thickness of the bonding material body 2 and more preferably 0.9 to 1.1 times. If the thickness of the porous metal layer 3a is too small with respect to the thickness of the bonding material main body 2, reliable electrical connection may be difficult. On the other hand, if the thickness of the porous metal layer 3a is too large with respect to the thickness of the bonding material main body 2, reliable bonding may be difficult.

  By the way, when manufacturing the fuel cell, the separator shrinks in the firing step. As a result, irregularities are formed on the surface of the separator. For this reason, for example, in the case of an interconnector described in Patent Document 1, when a dense electrical connection material is used that includes a perovskite oxide, contact between the via-hole electrode provided in the separator and the electrical connection material The area is reduced and the contact resistance is increased. As a result, the electrical resistance between the fuel cells increases.

  On the other hand, in this embodiment, the electrical connection part 3 which comprises the electrical connection material contains the porous metal layer 3a. For this reason, when the unevenness | corrugation is formed in the surface of the connection object of the electrical connection part 3, the surface of the electrical connection part 3 deform | transforms with respect to the shape dimension of the unevenness | corrugation. Therefore, the reduction of the contact area between the electrical connection part 3 and the connection object can be suppressed. Therefore, the fuel cells can be suitably electrically connected.

  In the present embodiment, the example in which the entire electrical connection portion 3 is configured by the porous metal layer 3a has been described. However, the present invention is not limited to this configuration. The electrical connection portion 3 constituting the electrical connection material may be configured by a laminate of at least one porous metal layer 3a and at least one dense layer. In that case, it is preferable that the surface layer of the electrical connection part 3 is comprised by the porous metal layer 3a.

  In the present embodiment, the constraining layer 11 is laminated on the glass ceramic layer 10. The constraining layer 11 suppresses shrinkage along the surface direction when the glass ceramic layer 10 is fired. For this reason, when the bonding material 1 of the present embodiment is used, even when the bonding material 1 is baked, the bonding material 1 does not shrink so much along the surface direction. Therefore, it can suppress more effectively that the joining material main body 2 peels from a to-be-joined material. Therefore, the materials to be joined can be joined more reliably.

  Hereinafter, other examples of preferred embodiments of the present invention will be described. In the following description, members having substantially the same functions as those of the first embodiment are referred to by common reference numerals, and description thereof is omitted.

<< Second and Third Embodiments >>
FIG. 3 is a schematic perspective view of the solid oxide fuel cell bonding material according to the second embodiment. FIG. 4 is a schematic perspective view of a solid oxide fuel cell bonding material according to a third embodiment.

  In the first embodiment, the example in which the electrical connecting portion 3 reaches the one end edge of the solid oxide fuel cell bonding material 1 has been described. However, the present invention is not limited to this configuration. For example, as shown in FIGS. 3 and 4, the electrical connection portion 3 does not reach the edge of the solid oxide fuel cell bonding material 1 at the center of the solid oxide fuel cell bonding material 1. It may be provided as follows.

  Further, in the third embodiment shown in FIG. 4, an adhesive portion 4 made of glass ceramics is provided between the bonding material main body 2 and the electrical connection portion 3. The adhesion strength between the bonding material main body 2 and the electrical connection portion 3 is enhanced by the adhesion portion 4.

<< Fourth to seventh embodiments >>
FIG. 5 is a schematic cross-sectional view of a joining material body of a joining material for a solid oxide fuel cell according to a fourth embodiment. FIG. 6 is a schematic cross-sectional view of a bonding material body of a solid oxide fuel cell bonding material according to a fifth embodiment. FIG. 7 is a schematic cross-sectional view of a bonding material body of a bonding material for a solid oxide fuel cell according to a sixth embodiment. FIG. 8 is a schematic cross-sectional view of a joining material body of a joining material for a solid oxide fuel cell according to a seventh embodiment.

  In the first embodiment, the example in which the bonding material main body 2 is configured by a laminate of one glass ceramic layer 10 and one constraining layer 11 has been described. However, the present invention is not limited to this configuration.

  For example, as shown in FIGS. 5 to 8, the bonding material body 2 may include a plurality of at least one of the glass ceramic layer 10 and the constraining layer 11.

  In the example shown in FIG. 5, the first glass ceramic layer 10a is provided on one main surface of the constraining layer 11, and the second glass ceramic layer 10b is provided on the other main surface. . Therefore, both surfaces of the bonding material are composed of glass ceramic layers. Accordingly, both the bonding strength between the bonding material to be bonded to one main surface of the bonding material and the bonding material, and the bonding strength between the bonding material to be bonded to the other main surface of the bonding material and the bonding material. Can be increased.

  In the example shown in FIG. 6, constraining layers 11 a and 11 b are provided on both sides of the glass ceramic layer 10. That is, the glass ceramic layer 10 is sandwiched between the constraining layers 11a and 11b. Therefore, shrinkage during firing of the glass ceramic layer 10 can be more effectively suppressed.

  In the example shown in FIG. 7, two constraining layers 11a and 11b are arranged between three glass ceramic layers 10a to 10c. For this reason, both surfaces of the bonding material are composed of glass ceramic layers. Accordingly, both the bonding strength between the bonding material to be bonded to one main surface of the bonding material and the bonding material, and the bonding strength between the bonding material to be bonded to the other main surface of the bonding material and the bonding material. Can be increased. Further, since the number of constraining layers with respect to the number of glass ceramic layers is larger than that of the bonding material shown in FIG. 5, shrinkage during firing of the glass ceramic layers 10 a to 10 c can be more effectively suppressed.

  In the example shown in FIG. 8, two glass ceramic layers 10a and 10b and two constraining layers 11a and 11b are alternately stacked. Even in this case, the same effect as in the first embodiment can be obtained.

<< Eighth Embodiment >>
FIG. 9 is a schematic cross-sectional view of an electrical connection portion of the solid oxide fuel cell bonding material according to the eighth embodiment.

  In 1st Embodiment, the electrical connection part 3 demonstrated the example which consists only of the porous metal layer 3a. However, the present invention is not limited to this configuration. For example, the electrical connection part 3 may be comprised by the laminated body of the porous metal layer and the metal layer which does not have a pore substantially.

  As shown in FIG. 9, in this embodiment, the electrical connection portion 3 is disposed between the two porous metal layers 3a1 and 3a2 and the porous metal layers 3a1 and 3a2, and substantially has pores. It is comprised by the metal layer 3b which does not have.

  Further, instead of the metal layer 3b, a layer made of another conductive material may be provided. For example, a layer made of LSM (Lanthanum Strontium Manganite) or the like may be provided.

<< Ninth embodiment >>
FIG. 10 is a schematic side view of a solid oxide fuel cell module according to the ninth embodiment.

  As shown in FIG. 10, the solid oxide fuel cell module (also referred to as a hot module) 6 includes a housing 6a. A solid oxide fuel cell 5 is disposed inside the housing 6a.

  The fuel cell 5 has a plurality of power generation cells 20. Specifically, the fuel cell 5 has two power generation cells 20.

  FIG. 11 is a schematic exploded perspective view of the power generation cell according to the ninth embodiment. As shown in FIG. 11, the power generation cell 20 includes a first separator 40, a power generation element 46, and a second separator 50. In the power generation cell 20, the first separator 40, the power generation element 46, and the second separator 50 are stacked in this order.

  The power generation cell 20 is formed with an aerobic gas supply manifold 44 and a fuel gas supply manifold 45 which are through holes.

(Power generation element 46)
The power generation element 46 is a portion where the oxidant gas supplied from the oxidant gas supply manifold 44 reacts with the fuel gas supplied from the fuel gas supply manifold 45 to generate power. Here, the oxidant gas can be composed of, for example, an oxidant gas such as air or oxygen gas. The fuel gas may be a gas containing hydrogen gas, city gas, liquefied petroleum gas, hydrocarbon gas such as vaporized kerosene, and the like.

(Solid oxide electrolyte layer 47)
The power generation element 46 includes a solid oxide electrolyte layer 47. It is preferable that the solid oxide electrolyte layer 47 has high ionic conductivity. The solid oxide electrolyte layer 47 can be formed of, for example, stabilized zirconia or partially stabilized zirconia. Specific examples of the stabilized zirconia include 10 mol% yttria stabilized zirconia (10YSZ), 11 mol% scandia stabilized zirconia (11ScSZ), and the like. Specific examples of the partially stabilized zirconia include 3 mol% yttria partially stabilized zirconia (3YSZ). Further, the solid oxide electrolyte layer 47 is, for example, Sm and Gd or the like ceria oxides doped, a LaGaO ₃ as a host, _{La 0} the part of the La and Ga was substituted with Sr and Mg, _{respectively.} It can also be formed of a perovskite oxide such as ₈ Sr _0.2 Ga _0.8 Mg _0.2 O _(3-δ) .

  The solid oxide electrolyte layer 47 is sandwiched between the air electrode layer 48 and the fuel electrode layer 49. That is, the air electrode layer 48 is formed on one main surface of the solid oxide electrolyte layer 47, and the fuel electrode layer 49 is formed on the other main surface.

(Air electrode layer 48)
The air electrode layer 48 has an air electrode 48a. The air electrode 48a is a cathode. In the air electrode 48a, oxygen takes in electrons and oxygen ions are formed. The air electrode 48a is preferably porous, has high electron conductivity, and does not easily cause a solid-solid reaction with the solid oxide electrolyte layer 47 and the like at a high temperature. The air electrode 48a is, for example, scandia-stabilized zirconia (ScSZ), indium oxide doped with Sn, PrCoO ₃ oxide, LaCoO ₃ oxide, LaMnO ₃ oxide, La _0.8 Sr _0.2 Co _{0. .2} Fe _{0 .} It can be formed of ₈ O ₃ (common name: LSCF) or the like. Specific examples of LaMnO ₃ -based oxides include La _0.8 Sr _0.2 MnO ₃ (common name: LSM), La _{0. 6} Ca _0.4 MnO ₃ (common name: LCM) and the like. The air electrode 48a may be made of a mixed material obtained by mixing two or more of the above materials.

(Fuel electrode layer 49)
The fuel electrode layer 49 has a fuel electrode 49a. The fuel electrode 49a is an anode. In the fuel electrode 49a, oxygen ions and fuel gas react to emit electrons. The fuel electrode 49a is preferably porous, has high electron conductivity, and does not easily cause a solid-solid reaction with the solid oxide electrolyte layer 47 and the like at a high temperature. The fuel electrode 49a can be composed of, for example, NiO, yttria stabilized zirconia (YSZ) / nickel metal porous cermet, scandia stabilized zirconia (ScSZ) / nickel metal porous cermet, or the like. The fuel electrode layer 49 may be made of a mixed material obtained by mixing two or more of the above materials.

(First separator 40)
On the air electrode layer 48 of the power generation element 46, the first separator 40 constituted by the first separator body 41 and the first flow path forming member 42 is disposed. The first separator 40 is formed with an oxidant gas passage 43 for supplying an oxidant gas to the air electrode 48a. The oxidant gas flow path 43 extends from the aerobic gas supply manifold 44 toward the x2 side from the x1 side in the x direction.

  The constituent material of the first separator 40 is not particularly limited. The first separator 40 can be formed of, for example, stabilized zirconia such as yttria stabilized zirconia, partially stabilized zirconia, or the like.

(Second separator 50)
On the fuel electrode layer 49 of the power generation element 46, a second separator 50 constituted by a second separator body 51 and a second flow path forming member 52 is disposed. The second separator 50 is formed with a fuel gas passage 53 for supplying fuel gas to the fuel electrode 49a. The fuel gas passage 53 extends from the fuel gas supply manifold 45 toward the y2 side from the y1 side in the y direction.

  The constituent material of the second separator 50 is not particularly limited. The second separator 50 can be formed of, for example, stabilized zirconia, partially stabilized zirconia, or the like.

  FIG. 12 is a schematic exploded perspective view of a fuel cell according to the ninth embodiment. As shown in FIG. 12, in this embodiment, the two power generation cells 20 are joined using the joining material 1 described in the first embodiment. That is, the solid oxide fuel cell module 6 is manufactured by joining two power generation cells 20 using the joining material 1 described in the first embodiment. For this reason, the two power generation cells 20 can be suitably joined and electrically connected appropriately.

  Specifically, the two power generation cells 20 are joined by a first joining layer 21 a formed by firing the joining material 1. More specifically, the first bonding layer 21a includes a bonding layer body 21a1 formed of a laminate of the fired layer 22 formed by baking the glass ceramic layer 10 and the constraining layer 11, and in the thickness direction. It is comprised by the electrical connection part 3 which consists of the shrink | contracted porous metal layer 3a.

  FIG. 13 is a schematic exploded perspective view of a part of the fuel cell module according to the ninth embodiment. In FIG. 13, only a part of the housing 6a is drawn, and other parts are not drawn.

  As shown in FIG. 13, the fuel cell 5 is joined to the housing 6a by a second joining layer 21b. Similarly to the first bonding layer 21a, the second bonding layer 21b is formed by baking the bonding material 1. That is, the solid oxide fuel cell module 6 is manufactured by bonding the housing 6a and the power generation cell 20 of the fuel cell 5 using the bonding material 1 described in the first embodiment. For this reason, the power generation cell 20 and the housing 6a can be suitably joined and can be suitably electrically connected.

(Experimental example 1)
In Experimental Example 1, a glass ceramic layer was produced. First, polyvinyl butyral as a binder and di-n- as a plasticizer with respect to glass ceramics having a composition of SiO ₂ : 57.0 mass%, BaO: 31.0 mass%, and Al ₂ O ₃ : 12.0 mass%. A slurry was prepared by adding butyl phthalate and toluene and isopropylene alcohol as solvents. Using the slurry, a ceramic green sheet of a glass ceramic layer was produced by a doctor blade method. The thickness of the ceramic green sheet of the glass ceramic layer was 60 μm. The laminate obtained by laminating the ceramic green sheets of the glass ceramic layer was pressed at a temperature of 50 ° C. and a pressure of 500 kgf / cm ² to obtain a glass ceramic layer.

As an inorganic material that does not sinter at the sintering temperature of glass ceramics, alumina having a center particle size of 0.5 μm was used, and borosilicate glass having a center particle size of 1.3 μm was used as glass. After mixing alumina and glass in a volume ratio of 6: 4, a slurry was prepared by adding polyvinyl butyral as a binder, di-n-butyl phthalate as a plasticizer, and toluene and isopropylene alcohol as solvents. Using the slurry, a ceramic green sheet of a constraining layer was produced by a doctor blade method. In addition, the thickness of the ceramic green sheet of the constraining layer was 10 μm. A laminate obtained by laminating two ceramic green sheets of the constraining layer and three ceramic green sheets of the produced glass ceramic layer was pressed at a temperature of 50 ° C. and a pressure of 500 kgf / cm ² , A bonding material body, which is a laminate of constraining layers, was produced. The above-mentioned borosilicate glass is composed of 55 mol% SiO ₂ , 4 mol% Al ₂ O ₃ , 10 mol% B ₂ O ₃ , 20 mol% BaO, 5.5 mol% CaO, and MgO. A composition having a composition containing 0.5 mol% and 5 mol% SrO was used.

  In this experimental example, the glass ceramic layer and the constraining layer were separately prepared and laminated to prepare the bonding material main body. However, the constraining layer may be formed into a sheet on the glass ceramic layer.

  Further, the laminated structure of the glass ceramic layer and the constraining layer is not limited to the lamination of sheets, and the same effect can be obtained even by a paste method, a printing method, an aerosol deposition, or the like.

  As an electrical connection portion, a foamed silver sheet having a porosity of 95% and a thickness of 200 μm was cut into a predetermined size and used.

(Experimental example 2)
A sample was prepared in the same manner as in Experimental Example 1 except that a mixed sheet of silver and LSM prepared by the following method was used as the electrical connection portion.

LSM, carbon powder and silver powder were mixed at a volume ratio of 0.5: 1: 1 to obtain a mixed powder. A slurry was prepared by adding polyvinyl butyral as a binder, di-n-butyl phthalate as a plasticizer, and toluene and isopropylene alcohol as a solvent to the mixed powder. Using the slurry, a green sheet having an electrical connection portion having a thickness of 40 μm was prepared by a doctor blade method. A laminate obtained by laminating five green sheets of electrical connection parts was pressed at a temperature of 50 ° C. and a pressure of 500 kgf / cm ² to prepare a mixed sheet of silver and LSM, and cut into a predetermined size. used. In addition, the porosity of the produced electrical connection part was 40%.

(Experimental example 3)
A sample was prepared in the same manner as in Experimental Example 1 except that plate-like silver (porosity <1%) was used as the electrical connection portion.

(Example 1)
Under the conditions shown below, a power generation cell having a configuration substantially similar to that of the power generation cell according to the ninth embodiment was produced by integrally firing the following constituent members.

Constituent material of separator: 3YSZ (ZrO ₂ stabilized with Y ₂ O ₃ added in 3 mol%)
Constituent material of the solid oxide electrolyte layer: ScSZ (addition amount of 10 mol% Sc ₂ O ₃ , 1 mol% CeO ₂ stabilized ZrO ₂ )
Air electrode constituent material: La _0.8 Sr _0.2 MnO ₃ powder 60% by mass and ScSZ 40% by mass of carbon powder added 30% by mass Fuel electrode constituent material: NiO 65% by mass And 30% by mass of carbon powder with respect to a mixture of 35% by mass of ScSZ. Constituent material of the interconnector on the fuel electrode side: Mixture of 70% by mass of NiO and 30% by mass of TiO ₂ Constituent material of connector: Pd-Ag alloy with Pd content of 30% by mass Diameter of via hole: 0.2 mm
Fuel electrode thickness: 30 μm
Air electrode thickness: 30 μm
Solid oxide electrolyte layer thickness: 30 μm
Height of flow path forming part: 240 μm
Separator body thickness: 360 μm

  Two power generation cells prepared under the above conditions were prepared and fired at 1000 ° C. for 1 hour while applying a 1 kg weight load with the bonding material main body and electrical connection portion prepared in Experimental Example 1 interposed between the power generation cells. . A fuel cell having a configuration substantially similar to that of the fuel cell according to the ninth embodiment was produced.

(Example 2)
A fuel cell was produced in the same manner as in Example 1 except that the electrical connection part produced in Experimental Example 2 was used.

(Comparative Example 1)
A fuel cell was produced in the same manner as in Example 1 except that the electrical connection part produced in Experimental Example 3 was used.

(Evaluation)
The fuel cells produced in Examples 1 and 2 and Comparative Example 1 were heated to 900 ° C., and after the humidified hydrogen was supplied to the fuel electrode side to reduce the fuel electrode, the IR resistance of the entire fuel cell was measured with an impedance analyzer. The value obtained by removing the IR resistance of the power generation cell from the obtained IR resistance was taken as the IR resistance of the electrical connection portion. As a result, IR resistance of 5 mΩ or less was obtained in Example 1, Example 2, and Comparative Example 1.

Further, each of the fuel gas supply manifold of the fuel cell to the oxidant gas supply manifold flowing at room temperature with N ₂ gas, the leak checker evaluation pressure in the manifold is whether the gas leakage when 10kPa from commercial surfactants When the sealing properties of the solid oxide fuel cell bonding material were evaluated, no gas leak was observed in Examples 1 and 2. In Comparative Example 1, a gas leak occurred. The plate-like silver used for the electrical connection part did not follow the shrinkage of the joint material body, and the thickness of the electrical connection part was too thick compared to the thickness of the joint material body. It is thought that they have left.

DESCRIPTION OF SYMBOLS 1 ... Joining material for solid oxide fuel cells 2 ... Bonding material main body 3 ... Electrical connection part 3a ... Porous metal layer 3b ... Metal layer 4 ... Adhesion part 5 ... Solid oxide fuel cell 6 ... Solid oxide form Fuel cell module 6a ... Case 10, 10a-10c ... Glass ceramic layers 11, 11a, 11b ... Constraining layer 20 ... Power generation cell 21a1 ... Junction layer body 21a ... First joining layer 21b ... Second joining layer 22 ... Firing Layer 40 ... First separator 41 ... First separator body 42 ... First flow path forming member 43 ... Oxidant gas flow path 44 ... Oxidant gas supply manifold 45 ... Fuel gas supply manifold 46 ... Power generation element 47 ... Solid oxide electrolyte layer 48 ... Air electrode layer 48a ... Air electrode 49 ... Fuel electrode layer 49a ... Fuel electrode 50 ... Second separator 51 ... Second separator body 52 ... Second flow path forming member 53 ... Fuel gas Flow path

Claims (12)

A plate-shaped, solid oxide fuel cell bonding material that is joined to and electrically connected to a power generation cell on one main surface, and joined to and electrically connected to another material to be joined on the other main surface. Because
A bonding material body;
The bonding material body is disposed at a different position in plan view, and includes an electrical connection portion including a porous metal layer,
The bonding material body includes a glass ceramic layer containing silica, barium oxide, and alumina;
Wherein provided on the glass ceramic layer, and looking containing alumina and glass, said having a glass-ceramic layer suppresses constraining layer shrinkage along the surface direction during the firing of the solid oxide fuel cell Bonding material.   The bonding material for a solid oxide fuel cell according to claim 1, wherein the porous metal layer is made of a foam metal.   The solid oxide fuel cell bonding material according to claim 1 or 2, wherein the porosity of the porous metal layer is 10% by volume to 95% by volume.   The porous metal layer is made of a metal selected from the group consisting of silver, gold, palladium, nickel and stainless steel, or an alloy containing at least one metal selected from the group consisting of silver, gold, palladium, nickel and stainless steel. The joining material for a solid oxide fuel cell according to any one of claims 1 to 3.   The bonding material for a solid oxide fuel cell according to claim 1, wherein the constraining layer does not sinter or melt at a sintering temperature of the glass ceramic layer.   The solid oxide fuel cell bonding material according to claim 1, wherein a content of the alumina in the constrained layer is 30% by mass to 90% by mass. The solid oxide fuel cell joint according to any one of claims 1 to 6 , further comprising an adhesive portion that is provided between the bonding material main body and the electrical connection portion and is made of glass ceramics. Wood. A method for producing a solid oxide fuel cell, wherein a plurality of power generation cells are joined and electrically connected using the joining material for a solid oxide fuel cell according to any one of claims 1 to 7 . Electrically connecting with joining a power generation cell, and other power generation cell or enclosure using a solid oxide fuel cell bonding material according to any one of claims 1 to 7 solid oxide Manufacturing method of fuel cell module. A bonding layer comprising a sintered body of the solid oxide fuel cell bonding material according to any one of claims 1 to 7 ,
A plurality of power generation cells joined and electrically connected by the joining layer;
A solid oxide fuel cell. Comprising a solid oxide fuel cell according to claim 1 0, a solid oxide fuel cell module. A bonding layer comprising a sintered body of the solid oxide fuel cell bonding material according to any one of claims 1 to 7 ,
A fuel cell;
A housing that is joined to and electrically connected to the fuel cell by the joining layer;
A solid oxide fuel cell module comprising: A solid oxide fuel cell module comprising:

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