JP2018092783A - Manufacturing method of fuel cell and cylindrical fuel cell - Google Patents

Abstract

A fuel cell manufacturing method and a cylindrical fuel cell capable of reducing electrical resistance between a current collector and a cathode layer joined and electrically connected with a current collector junction layer interposed therebetween I will provide a. A method of manufacturing a fuel cell 100, comprising: a cathode layer 2 and a current collecting bonding layer forming sheet J0; or a current collecting bonding layer forming sheet J0 and a current collecting member E; Adhesion assistance for making the current collecting bonding layer forming sheet J0 deformable and bringing the current collecting member E and the current collecting bonding layer forming sheet J0 into close contact with each other. After the current collecting bonding layer forming sheet arranging step for applying the agent A and the current collecting bonding layer forming sheet arranging step, the cathode layer 2 or / and the current collecting member E and the current collecting bonding layer forming sheet J0 It is heated while maintaining a close contact state between them, and a collector bonding layer J is formed, and a cathode layer 2 and a collector member E are bonded. [Selection] Figure 6

Description

  The present invention relates to a method for manufacturing a fuel cell and a cylindrical fuel cell.

  Conventionally, for example, between a cathode layer of a fuel cell (hereinafter also referred to as an air electrode) and a current collecting member that electrically connects a plurality of fuel cells, both are joined and electrically A structure in which a current-collecting bonding layer for connection is laminated is known.

  In order to form the above structure, in the fuel cells described in Patent Documents 1 and 2, the current collecting bonding layer is formed using a conductive paste containing a predetermined amount of solvent. Heat treatment is performed in a state where the conductive paste is sandwiched between the cathode layer and the current collecting member, the conductive paste is baked on the current collecting member or the air electrode, and both are bonded to form a current collecting bonding layer.

  Specifically, in the fuel cell of Patent Document 1, a contact layer 24 (corresponding to a current collecting bonding layer) is provided between the air electrode surface 18 a and the current collector 12. The contact layer 24 has a double stacked structure of a first part 241 joined to the surface 18 a of the air electrode and a second part 242 joined to the current collector 12. For example, the first part 241 is formed by screen-printing the first part material 241 a on the air electrode 18 and then heating. A manufacturing method for joining the contact layer 24 to the air electrode 18 by forming the second portion 242 in the same manner is disclosed. In the fuel cell of Patent Document 2, the air electrode has a double stacked structure of an air electrode base 181 and an air electrode convex 182. The air electrode convex portion 182 is stacked on the current collecting metal side of the air electrode base portion 181 that is stacked on the electrolyte layer side and mainly performs the electrode reaction. The air electrode convex portion 182 is a layer that is expected to have electronic conductivity, and is understood to correspond to a current collecting bonding layer. As a material for forming the air electrode convex portion 182, a convex portion forming material having an adjusted amount of solvent is used. A manufacturing method is disclosed in which this is pressed against the metal current collector 12 and then baked to join the metal current collector 12 to the air electrode convex portion 182.

  Moreover, in order to form said structure, in the fuel battery cell of patent document 3, 4, it replaces with said electroconductive paste, and uses the electroconductive sheet by which the content amount of solvent was restrict | limited, and a current collection joining layer As a material to form.

  Specifically, in the fuel cell described in Patent Document 3, connection between the cell 5 and the current collecting member 7 is performed using a sheet-like molded body having no fluidity. After the adhesive conductive sheet 6 formed from a slurry containing a binder and conductive metal particles as a component is attached to the cell 5 or the current collector 7, the cell 5 and the current collector 7 are bonded together. When the cell stack is manufactured, the cell 5 and the current collecting member 7 are bonded to each other due to the adhesiveness of the resin binder, and a heat history of about 700 to 1000 ° C. which is the operating temperature of the fuel cell is added, so The manufacturing method which bakes the cell 5 and the current collection member 7 with a conductive metal particle is disclosed. In the fuel cell described in Patent Document 4, a (current collection) connection layer is provided between a separator and an air electrode arranged between adjacent single cells. As the connection layer forming material, a connection layer forming sheet is used in which a conductive metal oxide powder is formed into a sheet shape integrally with an organic binder. A manufacturing method is disclosed in which the connection layer forming sheet is sandwiched between an air electrode and a separator, heated to the operating temperature of the fuel cell, the organic binder is removed, and a connection layer is formed to join them together.

JP 2016-24996 A JP-A-2006-9649 JP 2008-71676 A Japanese Patent No. 5189405

  However, in the manufacturing method in which the air electrode or the current collecting bonding layer is formed using the conductive paste described in Patent Documents 1 and 2, the solvent in the conductive paste inevitably evaporates during the heat treatment. Therefore, the volume of the conductive paste shrinks (decreases in volume), and cracks and voids are generated in the bonding member such as the current collecting bonding layer to be formed after the heat treatment. Cracks and voids generated in the joining member itself reach the boundary surface with the joined member such as a current collecting member to be joined with the conductive paste adhered, and between the joined member and the joined member formed after heat treatment. There is a risk that the contact resistance of the fuel cell increases and the power generation performance of the fuel cell decreases.

  Moreover, in the manufacturing method which forms a current collection joining layer using the electroconductive sheet of patent document 3, 4, an electroconductive sheet and to-be-joined member are closely_contact | adhered before heat processing rather than the case where an electroconductive paste is used. It becomes difficult to make contact in a state. In particular, when a member having a surface roughness different from that of a conductive sheet mainly composed of a conductive metal oxide is joined, difficulty increases. In addition, since the conductive sheet is harder than the conductive paste, for example, it is difficult to make contact with a curved surface such as the surface of a cylindrical fuel cell. There is a possibility that voids remain at the boundary surface between the current collecting bonding layer after the conductive sheet is formed by heat treatment and the member to be bonded such as the current collecting member, and the bonding between the two becomes insufficient. As in the case of using the conductive paste, the contact resistance between the current collecting bonding layer formed after the heat treatment and the member to be bonded is increased, and there is a possibility that the power generation performance of the fuel cell is lowered.

  The present invention has been made in view of such circumstances, and reduces the electrical resistance between the cathode layer and the current collector member joined and electrically connected with the current collector junction layer interposed therebetween. An object of the present invention is to provide a method of manufacturing a fuel cell and a cylindrical fuel cell that can be used.

  The fuel cell manufacturing method of the present invention includes an electrolyte layer, an anode layer disposed on one side of the electrolyte layer and under a fuel gas atmosphere, and a cathode layer disposed on the other side of the electrolyte layer and under an oxidant gas atmosphere And a current collecting member that is electrically connected to face the cathode layer and supplies electrons to the cathode layer, and is provided between the cathode layer and the current collecting member, and joins the cathode layer and the current collecting member; A current collecting joint layer electrically connected, and the current collecting joint layer is formed using a sheet for forming a current collecting joint layer formed of a conductive metal oxide as a main component and formed into a sheet shape. A method for producing a fuel cell, wherein when a current collecting bonding layer forming sheet is provided between a cathode layer and a current collecting member, between the cathode layer and the current collecting bonding layer forming sheet, or Between the current collecting bonding layer forming sheet and the current collecting member , A collecting auxiliary agent for making the current collecting bonding layer forming sheet deformable and adhering the cathode layer or / and the current collecting member and the current collecting bonding layer forming sheet to each other. After the electric bonding layer forming sheet arranging step and the current collecting bonding layer forming sheet arranging step, the contact state between the cathode layer and / or the current collecting member and the current collecting bonding layer forming sheet is maintained. A baking step of heating to form a current collecting bonding layer and bonding the cathode layer to the current collecting member.

  According to the method for producing a fuel cell of the present invention, the current collecting bonding layer forming sheet can be deformed between at least one of the cathode layer and the current collecting member and the current collecting bonding layer forming sheet. At the same time, an adhesion aid for attaching the cathode layer or / and the current collecting member and the current collecting bonding layer forming sheet is attached. Since the current collecting bonding layer forming sheet can be deformed, flexibility can be imparted to the current collecting bonding layer forming sheet. The current collecting bonding layer forming sheet can be disposed along the surface of the cathode layer and / or the surface of the current collecting member. Further, since the current collecting bonding layer forming sheet can be adhered to the cathode layer and / or current collecting member, the surface of the uneven cathode layer or / and the surface of the current collecting member and the uneven current collecting bonding layer are formed. Adhesion with the surface of the sheet can be further increased. The conductive metal oxide particles in the current collecting bonding layer forming sheet are likely to enter the concave portions of the surface of the cathode layer and / or the surface of the current collecting member. When the conductive metal oxide particles and the component particles forming the surface of the cathode layer or / and the current collecting member are close to each other, the interaction between the two particles is facilitated, and the adhesion between the particles is increased. The voids at the contact interface between the layer or / and the current collecting member and the current collecting bonding layer forming sheet are reduced. Even after performing the baking step, a state where there are few voids at the bonding interface is maintained, the bonding strength between the cathode layer and / or the current collecting member and the current collecting bonding layer is increased, and an increase in contact resistance is suppressed. Therefore, the power generation performance of the fuel cell can be enhanced.

It is a figure which shows SOFC of 1st embodiment. It is a figure which shows each process of the manufacturing method of the fuel cell of 1st embodiment. It is a figure which shows the manufacturing process of a single cell. It is a figure explaining the sheet | seat arrangement | positioning process (1) for current collection joining layer formation. It is a figure explaining the sheet | seat arrangement | positioning process (2) for current collection joining layer formation. It is a figure explaining the sheet | seat arrangement | positioning process (3) for current collection joining layer formation. It is a figure explaining a baking process. It is a schematic diagram for demonstrating the effect | action which attaches a close_contact | adherence adjuvant. It is a graph which shows the effect of the SOFC cell of a first embodiment. It is a figure explaining the cylindrical SOFC cell of 2nd embodiment.

  Hereinafter, a method for producing a solid oxide fuel cell (hereinafter also simply referred to as “SOFC”) using an oxide ion conductive solid electrolyte as an example of the fuel battery cell of the present invention will be described.

<< first embodiment >>
[SOFC cell]
First, the configuration of the SOFC cell 100 according to the SOFC cell manufacturing method of the first embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the structure of a flat plate-type SOFC cell 100 according to the first embodiment. As shown in the figure, the flat SOFC cell 100 is arranged between a plurality of single cells C and adjacent single cells C, and the anode layer 1 of the single cell C on one side and the cathode layer of the single cell C on the other side. 2 between the current collecting member E electrically connected to 2 and the cathode layer 2 and current collecting member E of the single cell C on the other side. Current-collecting junction layer J connected to each other. The SOFC cell 100 is formed by alternately laminating a plurality of flat single cells C and current collecting members E along their normal (up and down) directions with their surfaces (upper and lower surfaces in the drawing) facing each other. In the same manner, a flat current collecting bonding layer J is alternately laminated in the vertical direction so as to face the other surface of the current collecting member E and the surface of the cathode layer 2 of the single cell C. Have.

(Single cell)
The single cell C is a cell body that generates power as a fuel cell in the SOFC cell 100. The single cell C includes a flat thin-film electrolyte layer 3, a similarly flat cathode layer 2 provided on one side (upper side in the drawing) of the electrolyte layer 3 in an oxidizing gas atmosphere, a cathode Similarly, a flat thin-film intermediate layer 4 provided between the layer 2 and the electrolyte layer 3, and the same provided on the other side (lower side in the drawing) of the electrolyte layer 3 in the fuel gas atmosphere And a flat anode layer 1.

The anode layer 1 is a fuel electrode in which the fuel gas flowing through the electrode and the oxygen ions that have moved through the electrolyte layer 3 are in contact with each other, and an electrode reaction in which the fuel gas is oxidized to generate electrons proceeds. In the first embodiment, hydrogen is used as the fuel gas, but it may be a hydrocarbon such as methane or propane.
The electrolyte layer 3 is a layer that forms a path for moving oxygen ions generated in the cathode layer 2 to the anode layer 1. The electrolyte layer 3 has high oxygen ion conductivity and low electronic conductivity, and is densely formed so as not to transmit gas.
The cathode layer 2 is an air electrode that reduces oxygen in the air with electrons supplied into the electrode and sends the oxygen as oxygen ions to the electrolyte layer 3. In the cathode layer 2, the oxygen supplied in the electrode through the current collecting member E and the current collecting bonding layer J is consumed by oxygen in the air, generates oxygen ions, and moves the oxygen ions to the electrolyte layer 3. The reaction proceeds. In the first embodiment, air is used as the oxidant gas, but other oxidant gas (for example, pure oxygen) may be used.
The intermediate layer 4 is formed as a barrier layer for a reaction that generates a high resistance component from a predetermined component in the cathode layer 2 and a predetermined component in the electrolyte layer 3, and is provided between the electrolyte layer 3 and the cathode layer 2. It is done. For example, when selecting a cobaltite-based oxide having a perovskite structure as the cathode electrode material and selecting a zirconium oxide-based oxide such as yttria stabilized zirconia (hereinafter also referred to as “YSZ”) as the electrolyte layer material, This is because a high resistance component is generated at these contacting portions (interfaces), and oxygen ion conductivity may be reduced.

(Current collector)
The current collecting member E is interposed between adjacent single cells C, and the anode layer 1 of the single cell C disposed on one side of the current collecting member E and the cathode layer 2 of the single cell C disposed on the other side. Between the two. The current collecting member E is a member that collects electrons generated in the anode layer 1 of the single cell C on one side and forms an electron movement path to supply the electrons to the cathode layer 2 of the single cell C on the other side. is there. The current collecting member E also serves as a separator that separates the oxidizing oxidant gas supplied to the cathode layer 2 and the reducing fuel gas supplied to the anode layer 1. On one surface of the current collecting member E facing the anode layer 1, a flow path Ea through which fuel gas flows is formed (in the left-right direction in the drawing), and the other side of the current collecting member E facing the cathode layer 2. Is formed with a flow path Ec through which the oxidant gas flows (in the front-back direction in the drawing).

  The current collecting member E can be formed using a known material, and is not particularly limited. For example, the current collecting member E can be obtained by molding using a metal plate such as Ni, Fe—Cr, or SUS. Alternatively, it can be obtained by firing and cutting a mixture of a predetermined conductive material and a binder.

(Current collector bonding layer)
The current collecting bonding layer J is a layer for bonding the current collecting member E and the single cell C, and is sandwiched between the other surface of the current collecting member E and the surface of the cathode layer 2 of the single cell C. Both are joined in such a state. The current collecting bonding layer J is formed of a conductive material that electrically connects the current collecting member E and the cathode layer 2, and supplies the electrons collected by the current collecting member E to the cathode layer 2 of the single cell C. To relay. Further, as will be described later, the current collecting bonding layer J is formed using a current collecting bonding layer forming sheet J0 which is mainly formed of a conductive metal oxide and is formed into a sheet shape.

[Manufacture of SOFC cells]
Next, a method for manufacturing the SOFC cell 100 according to the first embodiment will be described. In the manufacturing method of the SOFC cell 100 of this embodiment, as shown in FIG. 2, the preparation process for producing the single cell C that is the main body of the SOFC cell 100 in step S1, the cathode layer 2 in step S2 and step S3, The current collecting bonding layer forming sheet J0 is provided between the current collecting member E and the current collecting bonding layer forming sheet J0. In step S4, the current collecting bonding layer forming sheet J0 is baked to form the current collecting bonding layer J. A baking step to be formed. In the manufacturing method of the SOFC cell 100 of the present embodiment, in the current collecting bonding layer forming sheet disposing step, between the cathode layer 2 and the current collecting bonding layer forming sheet J0 or for collecting the current collecting bonding layer. Adhesion between the sheet J0 and the current collecting member E so that the current collecting bonding layer forming sheet J0 can be deformed and the cathode layer 2 and the current collecting bonding layer forming sheet J0 are in close contact with each other. Adjunct A is added. That is, it can manufacture similarly to the manufacturing method of a conventionally well-known SOFC cell except this characteristic process.

  Hereinafter, in the present specification, the expression “attaching” in “attaching an adhesion aid” refers to, for example, the concept of applying to one side, applying, applying, spotting, infiltrating, and placing on the surface. Used as a superordinate concept.

[Preparing Step of Single Cell C: Step S1]
First, the step of manufacturing the cell body (single cell C) in step S1 will be described in detail. The manufacturing procedure of the single cell C is based on a well-known manufacturing method. For example, as shown in FIG. 3, (1) the anode layer precursor 10, the electrolyte layer precursor 30, and the intermediate layer precursor 40 are laminated, and (2) a half cell laminate HC obtained by co-firing in advance is obtained. . (3) The single cell C can be produced by a method in which the cathode layer precursor 20 is laminated on the intermediate layer 4 of the half cell laminate HC and (4) firing.

(Anode layer precursor)
The anode layer precursor 10 can be prepared by preparing a slurry by adding a binder, a pore former and a solvent to a mixed powder of a ceramic material powder and a metal material powder forming the anode layer 1 and mixing them. Next, a green sheet is produced from this slurry, cut into a predetermined shape, and then dried. Thereby, the green sheet-like anode layer precursor 10 is obtained. As the binder for adjusting the slurry, polyvinyl butyral, ethyl cellulose or the like, as the pore-forming agent, fine particles such as polymethyl methacrylate or carbon, and as the solvent, toluene, butanol or ethanol can be suitably used.

As a material for forming the anode layer 1, a known ceramic material powder in an appropriate electrolyte layer is mixed with a metal material powder selected in consideration of catalytic activity, stability in a reducing atmosphere, cost, and the like. Cermets can be used. Although there is no particular limitation, a typical example is Ni-YSZ cermet in which YSZ as a ceramic material is mixed with nickel oxide (NiO) as a metal material. As the ceramic material, scandia-stabilized zirconia (ScSZ), gadolinia-doped ceria (GDC), samarium-doped ceria (SDC), or the like can be used instead of YSZ. As the metal material, Fe, Co, Ru, Pd, Pt, or the like can be used instead of Ni.
The anode layer 1 may have a function as a support for supporting the thin-film other layer of the single cell C. The thickness of the anode layer 1 may be, for example, about 10 μm to 300 μm. However, when the anode layer 1 is used as a support, the thickness of the anode layer 1 can be made larger than the thickness of other layers.

(Electrolyte layer precursor)
Similarly to the anode layer precursor 10, the electrolyte layer precursor 30 is prepared by adding a binder to the electrolyte layer material powder and mixing in a solvent to prepare a slurry. The slurry is screen-printed on the surface of the anode layer precursor 10. It can be produced by laminating and drying.
The material for forming the electrolyte layer 3 is not particularly limited, but zirconia (ZrO ₂ ) stabilized by adding a heterovalent metal oxide such as Y can be used. Specifically, at least one selected from Y ₂ O ₃ , Yb ₂ O ₃ , Sc ₂ O ₃ , Gd ₂ O ₃ , Sm ₂ O ₃ , CeO _{2 and the} like is used as the heterovalent metal oxide. be able to. Among these, YSZ stabilized with Y ₂ O ₃ can be preferably used. The amount of the heterovalent metal oxide added can be about 5 mol% to 10 mol%. The thickness of the electrolyte layer 3 should just be about 30 micrometers, for example.

(Interlayer precursor)
Similarly to the electrolyte layer precursor 30, the intermediate layer precursor 40 is prepared by adding a binder to the intermediate layer material powder and mixing in a solvent to prepare a slurry, which is screen-printed on the surface of the electrolyte layer precursor 30. It can be produced by laminating and drying.
As a material for forming the intermediate layer, cerium oxide can be used. Specifically, CeO ₂ doped with Y ₂ O ₃ , Gd ₂ O ₃ , Sm ₂ O ₃ or the like can be given. The thickness of the intermediate layer 4 may be about 10 μm, for example.

(Half cell laminate)
Next, the half-cell precursor HC0 in which the anode layer precursor 10, the electrolyte layer precursor 30, and the intermediate layer precursor 40 are sequentially laminated is co-fired over a temperature (for example, 1300 ° C. or higher) and time suitable for firing them. As a result, a half-cell laminate HC in which the anode layer 1, the electrolyte layer 3 and the intermediate layer 4 are laminated is obtained. In addition, after producing the laminated body by co-firing the half cell precursor which laminated | stacked the anode layer precursor 10 and the electrolyte layer precursor 30 in order, the slurry of the intermediate | middle layer precursor 40 on the surface of the electrolyte layer 3 of the laminated body The method of printing and baking again may be used. In addition, there is no limitation in particular about the method of laminating | stacking another precursor in order on each precursor, It can laminate | stack using a slurry coat method, a tape casting method, a doctor blade method etc. other than a screen printing method.

(Cathode layer precursor)
As with the anode layer precursor 10, the cathode layer precursor 20 is prepared by adding a binder, a pore forming agent and a solvent to the material powder of the cathode layer 2 and mixing them, and this slurry is half-cell laminated by screen printing. It can be produced by laminating on the surface of the intermediate layer 4 of the body HC and drying.
The material for forming the cathode layer 2 is not particularly limited, but contains at least one of La, Sr and Sm at the A site, and at least one of Ca, Mn, Co, Fe, Cr and Ni. An oxide having a perovskite structure containing at least seeds at the B site can be used. Specific examples include lanthanum strontium cobaltite (hereinafter also simply referred to as “LSC”), lanthanum strontium cobaltite ferrite (hereinafter also simply referred to as “LSFC”), samarium strontium cobaltite (SSC), and the like. . The thickness of the cathode layer 2 may be about 50 μm, for example.

  Then, the single cell precursor C0 obtained by laminating the slurry of the cathode layer precursor 20 on the surface of the intermediate layer 4 of the half cell laminate HC is subjected to a temperature suitable for firing (preferably 900 ° C. or more and 1250 ° C. or less). The firing is preferably carried out by holding for not less than 1 hour and not more than 12 hours. A single cell C of SOFC in which the anode layer 1, the electrolyte layer 3, the intermediate layer 4, and the cathode layer 2 are laminated can be produced.

[Current Disposition Bonding Layer Forming Sheet Arrangement Step: Steps S2 and S3]
Next, the current collecting bonding layer forming sheet disposing step corresponding to steps S2 and S3 in FIG. 2 will be described in detail. In the current collecting bonding layer forming sheet disposing step, the process of attaching and adhering the adhesion auxiliary agent in step S2, and the process of laminating the single cell C, the current collecting bonding layer forming sheet J0 and the current collecting member E in step S3. I do. First, the current collector bonding layer forming sheet J0 and the adhesion aid A used in the step S2 for attaching and infiltrating the adhesion aid will be described.

(Sheet for current collector bonding layer)
The current collecting bonding layer forming sheet J0 is a sheet for forming the current collecting bonding layer J for bonding the current collecting member E and the cathode layer 2 by performing heat treatment. The current collecting bonding layer forming sheet J0 is an unfired sheet that has a conductive metal oxide as a main component, has a uniform thickness, and has a predetermined fixed shape, unlike a paste. The current collecting bonding layer forming sheet J0 is formed in a substantially square flat plate shape so as to cover and overlap the entire surface of the cathode layer 2. The current collecting bonding layer forming sheet J0 is preferably formed into a sheet shape without containing a solvent. More preferably, the conductive metal oxide powder is bound with an organic binder so as to form a predetermined shape. In addition to the organic binder, the current collecting bonding layer forming sheet J0 can contain various additives such as a plasticizer, an antioxidant, a thickener, and a dispersant as required.

As the main component conductive metal oxide in the current collecting bonding layer forming sheet J0, the current collecting bonding layer J is exposed to an oxidant gas at a high temperature. A material that satisfies such conditions as high electrical conductivity, low temperature dependence of electrical conductivity, small endurance fluctuation, and ease of processing is selected. Furthermore, considering practical aspects such as cost, a material similar to the material for forming the cathode layer 2 described above can be used. From the viewpoint of placing more emphasis on conductivity than the material of the cathode layer 2, lanthanum cobaltite (LaCoO ₃ ) system, lanthanum manganese knight (LaMnO ₃ ) system, lanthanum ferrite (LaFeO ₃ ) system, lanthanum nickelite system (LaNiO ₃ ) Examples thereof include metal oxides having a perovskite type structure. More specifically, LaSrMnO _3, LSC, LSCF, LaCoNiO _{3 and the} like can be mentioned. Among these, LSC can be preferably used in consideration of the usage record.

  Although it does not specifically limit as an organic binder contained in the sheet | seat J0 for current collection joining layer formation, A well-known organic binder can be selected suitably and can be used. For example, (meth) acrylate copolymers, cellulose polymers such as ethyl cellulose, ethylene copolymers, styrene copolymers, vinyl acetate copolymers, vinyl butyral resins such as polyvinyl butyral, polyvinyl alcohol, etc. Examples thereof include rubbers such as vinyl alcohol resin and styrene butadiene rubber. Among these, ethyl cellulose or polyvinyl butyral can be preferably used.

(Adhesion aid)
The adhesion auxiliary agent A is an agent that acts on the current collecting bonding layer forming sheet J0 so that the current collecting bonding layer forming sheet J0 can be deformed and the cathode layer 2 and the current collecting bonding layer forming sheet J0 are in close contact with each other. . The adhesion aid A is not particularly limited as long as it has these functions, but as an example, a terpineol solvent or a solvent capable of dissolving the organic binder in the current collecting bonding layer forming sheet J0 can be preferably used. . Alternatively, as the adhesion aid A, a conductive paste in which a conductive metal oxide powder is dispersed in these solvents can be preferably used.

但し、一般式（１）中、Ｒ^１，Ｒ^２，Ｒ^３は、各々独立の水素原子または炭化水素基を示し、Ｒ^１，Ｒ^２およびＲ^３の少なくとも１つは水素原子でない。 (Terpineol solvent)
The terpineol solvent used as the adhesion aid A has a terpineol basic skeleton in addition to terpineol, and has a structure in which at least one of the terminal hydrogen or hydroxy group in the terpineol molecular structure is substituted with a hydrocarbon group A solvent can be included. Alternatively, a predetermined terpineol derivative may be used. Of the terpineol isomers α, β, γ, and δ, any terpineol may be defined as the basic skeleton. For example, if the molecular structure of α-terpineol is defined as the basic skeleton, an α-terpineol solvent represented by the following general formula (1) can be used.

However, in the general formula (1), R ¹ , R ² and R ³ each represents an independent hydrogen atom or hydrocarbon group, and at least one of R ¹ , R ² and R ³ is not a hydrogen atom.

R ¹ and R ² in the general formula (1) are each an independent hydrocarbon group, which is a hydrogen atom, an alkyl group or an alkoxy group. Although it does not specifically limit as an alkyl group, A C1-C14 linear or branched alkyl group is preferable, and a C1-C10 linear or branched alkyl group is more preferable. The alkoxy group is not particularly limited, but is preferably a linear or branched alkoxy group having 1 to 4 carbon atoms. In particular, R ¹ and R ² are preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group.

R ³ in the general formula (1) is a hydrocarbon group, which is a hydrogen atom, an alkyl group, an alkoxy group or an acyl group. The alkyl group and alkoxy group may be the same as described above. Examples of the acyl group include a formyl group, an acetyl group, a propanoyl group, and a benzoyl group. Any of R ¹ , R ² , and R ³ must be a hydrocarbon group. Further, as the terpineol derivative, an organic acid ester of terpineol is preferable, and specifically, dihydroterpineol acetate, dihydroterpinylpropionate, and the like can be used. Of the terpineol solvents, α-terpineol can be preferably used.

(Solvent that can dissolve organic binder)
The “solvent capable of dissolving the organic binder” used as the adhesion aid A is determined in relation to the organic binder used in the current collecting bonding layer forming sheet J0. For example, it is possible to select a solvent whose difference is as small as possible with reference to the difference between the solubility parameter of the organic binder to be used and the solubility parameter of the solvent. Although it is thought that a suitable solvent may change according to the kind of organic binder to be used, the organic solvent which has the use track record generally used as an example can be mentioned. Specific examples include alcohol solvents, ether solvents, ester solvents, ketone solvents, cyclic ether solvents, aromatic hydrocarbon solvents, and other organic solvents. More specifically, ethanol, isopropyl alcohol, isobutyl alcohol, octanol, ethylene glycol, α-terpineol, butyl cellosolve acetate, butyl carbitol acetate, butyl diglycol acetate, isobornyl acetate, butyl carbitol, butyl cellosolve, methyl ethyl ketone, cyclohexane , Toluene, xylene, etc., among which α-terpineol can be preferably used.

(Conductive paste)
The conductive paste used as the adhesion aid A is a paste obtained by dispersing the conductive metal oxide similar to the conductive metal oxide in the current collecting bonding layer forming sheet J0 in each of the above solvents. What was adjusted can be used preferably. It is preferable that the conductive paste used as the adhesion aid A can be applied thinly so as to cover the surface of the cathode layer 2, the surface of the current collecting member E, or the surface of the current collecting bonding layer forming sheet J0. The viscosity should be adjusted appropriately according to workability, and a binder or the like may be added if necessary.

(Treatment with adhesion aid)
Next, the process for attaching and infiltrating the adhesion aid in step S2 shown in FIG. 2 will be described. As shown in FIG. 4A, the SOFC single cell C, the current collecting member E, and the current collecting junction layer forming sheet J0 prepared as described above are prepared. The current collecting member E of the first embodiment is formed of a metal material, and the current collecting bonding layer forming sheet J0 is formed using LSC as a conductive metal oxide and polyvinyl butyral as an organic binder. Yes.

And the operation | work which apply | coats the adhesion adjuvant A is performed. Α-Terpineol is used as the adhesion aid A. FIG. 4B shows a state immediately after the adhesion auxiliary agent A is applied to the surface 22 of the cathode layer 2 (hereinafter also referred to as the cathode layer surface 22) and the convex surface E11 of the current collecting member facing the cathode layer 2. It is a figure. As shown in the figure, a straight convex portion E1 is formed on the surface of the current collecting member E facing the cathode layer 2 along the front-back direction (see FIG. 1). The convex portion E1 is a convex portion for forming the oxidant gas flow path Ec together with the adjacent concave portion E2.
When the adhesion aid A is applied to the surface of the current collecting member E, it may be applied to at least the convex surface E11 of the convex portion E1 that is to contact the current collecting bonding layer forming sheet J0. Although it may be applied to the entire surface E3 (surface including all of the convex surface E11, the concave surface E21, and the side surface E12 of the convex portion E1) of the current collecting member E facing the cathode layer 2, it may be applied to at least the convex surface E11. . Moreover, in the cathode layer 2, the method of apply | coating the adhesion adjuvant A uniformly along the cathode layer surface 22 is preferable. Although it is not always necessary to apply to the entire surface of the cathode layer, it is preferable to apply to the entire surface from the viewpoint of securing the bonding strength.
FIG. 4 (2) shows that the adhesion aid A is still attached on the cathode layer surface 22 and the convex surface E11 in a liquid state. In the drawing, partial hatching indicates that the adhesion aid A is liquid.

  Moreover, the location which apply | coats the adhesion adjuvant A is not limited to the said form. For example, it is applied to the upper surface J0e (hereinafter also referred to as the current collecting bonding layer forming sheet upper surface J0e) and the lower surface J02 (hereinafter also referred to as the current collecting bonding layer forming sheet lower surface J02) of the current collecting bonding layer forming sheet J0. It doesn't matter how. That is, as shown in FIG. 5, it may be applied to any one of the cathode layer surface 22 and the lower surface J02 of the current collecting bonding layer forming sheet J0 facing each other in the cathode layer side region CS. Moreover, what is necessary is just to apply | coat to either one of the upper surface J0e of the current collection joining layer formation sheet | seat J0 and the convex surface E11 (or whole surface E3) of a current collection member which mutually oppose in the current collection member side area | region ES. Further, as in the above-described embodiment, by interposing the adhesion auxiliary agent A in both the cathode layer side region CS and the current collecting member side region ES, the bonding strength is increased and the contact resistance is further reduced. Can increase the possibility of Alternatively, in the cathode layer side region CS, when the opposing surfaces are made of ceramic materials and the contact strength is assumed to be larger than that of the current collecting member side region ES due to a decrease in bonding strength, the cathode layer A method may be used in which the adhesion aid A is applied to either the front surface 22 or the lower surface J02 of the current collecting bonding layer forming sheet J0.

(Lamination process)
FIG. 5 shows that the fluidity of the adhesion aid A, which was still attached in the liquid state in FIG. 4 (2), is reduced and is attached on the cathode layer surface 22 and the convex surface E11. . In the drawing, the cross-sectional display indicated by somewhat dense dots shows a state where the adhesion aid A loses fluidity and adheres to the vicinity of the surface. On the cathode layer surface 22, the applied adhesion aid A is in a state of adhering to the surface while soaking into the ceramic material from the surface 22. The convex surface E11 is attached to the metal surface while spreading. Next to the process of applying the adhesion auxiliary agent A, the process proceeds to a process of laminating the single cell C, the current collecting bonding layer forming sheet J0 and the current collecting member E. At that time, as shown in FIG. Thus, the adhesion aid A may be adhered in a liquid state, and as shown in FIG. 5, after the application of the adhesion aid A, the adhesion aid A loses fluidity. It may be in a state of adhering to the surface.

  Next, as shown in FIG. 6, the process of laminating | stacking the single cell C, the sheet | seat J0 for current collection joining layers, and the current collection member E is performed. The cathode layer surface 22 of the single cell C and the current collecting bonding layer forming sheet lower surface J02 are brought into contact with or in close contact with each other, and the convex surface E11 of the current collecting member and the current collecting bonding layer forming sheet upper surface J0e are brought into contact with or brought into close contact with each other. . As schematically shown in the upper part of FIG. 8, the surface of the cathode layer 22, the upper and lower surfaces J0e and J02 of the current collecting bonding layer forming sheet J0, and the convex surface E11 of the current collecting member E are shown. May not necessarily be in a state of being in close contact with each other (adhered state) on the entire surface where the adhesion auxiliary agent A is applied. It is preferable if the entire surface is in close contact (adhesion state) after the lamination treatment, but if the next heat treatment is performed, the surface can be further deformed so as to approach the entire surface (adhesion state). Good, it is not necessary to be transformed into a close contact state immediately after the lamination process.

  In the laminating step, heating may be performed for the purpose of drying the laminated body, if necessary. By heating at a predetermined temperature, the organic binder in the current collecting bonding layer forming sheet J0 can be softened or melted to further improve the adhesion. The organic binder is a polymer material, and the adhesion aid A, which is an organic solvent, has a high probability of dissolving the polymer. By softening or melting the organic binder, the interaction between the polymer and the solvent molecule becomes stronger and easier to work, and the dissolution of the polymer starts by surpassing the interaction between the polymers (chains). As the dissolution of the polymer proceeds, so-called “wetting” of the surface of the current collecting bonding layer forming sheet J0 is enhanced, and the adhesion between the current collecting bonding layer forming sheet J0 and the cathode layer 2 or the current collecting member E Can be increased. The component (conductive metal oxide or the like) particles in the current collecting bonding layer forming sheet J0 flow so as to be close to the component (cathode electrode material) particles of the cathode layer 2 or the metal component particles of the current collecting member E. As shown in the lower part of FIG. 8, the current collecting bonding layer forming sheet J <b> 0 is deformed so as to fill the unevenness of the mating surface. As a result, the adhesiveness between both particles increases, and the gap at the bonding interface decreases. Even after the heat treatment, it is considered that the gap is kept small and contributes to the reduction of the ohmic resistance.

[Baking process: Step S4]
Next, the baking process (firing process) corresponding to step S4 in FIG. 2 will be described.
In the baking step, the current collecting bonding layer forming sheet J0 is baked, and is baked and bonded to the cathode layer 2 and the current collecting member E. The baking temperature is not particularly limited as long as it is a temperature at which the current collecting bonding layer forming sheet J0 can be baked. For example, the baking process can be performed at about 700 ° C to 1000 ° C. The time for maintaining the firing temperature can be, for example, about 0.5 to 5 hours. In addition, when performing said lamination process or baking process, you may apply the pressure of an up-down direction, and it is not necessary to apply the pressure of an up-down direction, but it is better to apply the pressure of an up-down direction. Can be manufactured. As described above, the adhesion auxiliary agent that enables the current collecting bonding layer forming sheet J0 to be deformed and the cathode layer 2 and the current collecting bonding layer forming sheet J0 to be in close contact in the current collecting bonding layer forming sheet disposing step. By attaching A, the SOFC cell 100 shown in FIG. 7 can be preferably manufactured.

[Example]
Next, examples of the first embodiment will be described. A power generation test was performed on the SOFC cell sample subjected to the current collecting bonding layer forming sheet disposing step using the adhesion auxiliary agent according to the present invention and the SOFC cell sample not performed, and the output characteristics of both cells were confirmed. Evaluation was made to compare the magnitude of the loss. Specifically, for a cell having a configuration conforming to SOFC 100 described in the embodiment, a sample using the material shown in Table 1 as a material of each component was manufactured. The configuration and manufacturing method of each sample differed only in the materials or members described in Table 1, and all other components were manufactured in the same configuration and manufacturing method. About each sample, the baking temperature at the time of a baking process was performed at 850 degreeC. As a solvent of the LSC paste according to Example 2 and Comparative Example 1, α-terpineol was used.

但し、表1中、密着補助剤Ａ１は、カソード層２と集電接合層形成用シートＪ０（集電接合層Ｊ）との間に塗布した剤を示し、密着補助剤Ａ２は、集電部材Ｅと集電接合層形成用シートＪ０（集電接合層Ｊ）との間に塗布した剤を示す。
実施例１，２、比較例２のサンプルセルで用いたＬＳＣシートとして、厚みが２００μｍのシート状のものを用意した。

However, in Table 1, adhesion aid A1 indicates an agent applied between the cathode layer 2 and the current collecting bonding layer forming sheet J0 (current collecting bonding layer J), and adhesion aid A2 is a current collecting member. The agent applied between E and the current collecting bonding layer forming sheet J0 (current collecting bonding layer J) is shown.
As the LSC sheets used in the sample cells of Examples 1 and 2 and Comparative Example 2, sheet-like sheets having a thickness of 200 μm were prepared.

[Power generation test]
Using the SOFC cells obtained in the examples and comparative examples, a power generation test was performed under the following conditions, and the output characteristics of each sample were measured. At an ambient temperature of 650 ° C., an electrode body made of a platinum mesh member is brought into contact with the exposed portion of the anode layer 1 to collect current on the anode electrode side. The current was collected on the cathode layer 2 side. 20% H ₂ / N ₂ with 3% humidification was used as the fuel gas, and air was used as the oxidant gas. The flow rates were 200 (ml / min) and 200 (ml / min), respectively. The voltage between the electrode bodies at each predetermined current density was measured. The relationship between the output voltage and the current is illustrated, and the measurement result of the ohmic loss is shown in the graph of FIG.

[Evaluation]
As shown in the figure, the samples using the current collecting bonding layer forming sheet J0 of LSC in Examples 1 and 2 and using the adhesion assistants A1 and A2 were superior to the samples of Comparative Examples 1 and 2. The power generation performance was shown. Adhesion aids A1 and A2 were α-terpineol and LSC paste, respectively, which showed better power generation performance than the samples of Comparative Examples 1 and 2. In the sample of Comparative Example 2, the LSC sheet peeled off from the cathode layer 2 and the current collecting member E during the test, and the power generation test could not be performed.

  In the fuel cell manufacturing method of the present invention, the current collecting bonding layer is formed using a current collecting bonding layer forming sheet formed by binding a conductive metal oxide with an organic binder into a sheet shape. It is preferable that the adhesion aid contains a solvent capable of dissolving the organic binder.

(Effects of the first embodiment)
As described in detail above, according to the SOFC 100 manufacturing method of the present embodiment, the SOFC cell 100 includes the electrolyte layer 3, the anode layer 1 disposed on one side of the electrolyte layer 3, and in the fuel gas atmosphere, and the electrolyte layer. 3, a cathode layer 2 disposed on the other side of the gas generator 3 and in an oxidant gas atmosphere, a current collector E electrically connected to the cathode layer 2 so as to face the cathode layer 2, and supplying electrons to the cathode layer 2; A current collecting joint layer J provided between the current collecting member E and joining and electrically connecting the cathode layer 2 and the current collecting member E. The current collecting joint layer J is electrically conductive. A current collecting bonding layer forming sheet formed between the cathode layer 2 and the current collecting member E, using the current collecting bonding layer forming sheet J0 which is mainly composed of a metal oxide and formed into a sheet shape. When J0 is provided, cathode layer 2 and current collecting junction layer type The current collecting bonding layer forming sheet J0 can be deformed between the sheet J0 or between the current collecting bonding layer forming sheet J0 and the current collecting member E. Current collecting bonding layer forming sheet arranging step for applying adhesion auxiliary agent A for making cathode layer 2 or / and current collecting member E and current collecting bonding layer forming sheet J0 in close contact with each other, and current collecting bonding layer forming sheet arrangement After the process, the cathode layer 2 and / or the current collecting member E and the current collecting bonding layer forming sheet J0 are heated while maintaining a close contact state to form the current collecting bonding layer J and the cathode layer 2 and the current collecting layer. A baking process for joining the electric member E.

  Between the cathode layer 2 and the current collecting bonding layer forming sheet J0 or between the current collecting bonding layer forming sheet J0 and the current collecting member E (preferably, the cathode layer) 2 and the current collecting bonding layer forming sheet J0 and between the current collecting bonding layer forming sheet J0 and the current collecting member E), the current collecting bonding layer forming sheet J0 can be deformed and the cathode. Adhesion aid A for adhering layer 2 or / and current collecting member E and current collecting bonding layer forming sheet J0 is applied. Since the current collecting bonding layer forming sheet J0 is deformable, flexibility can be imparted to the current collecting bonding layer forming sheet J0. The current collecting bonding layer forming sheet J0 can be disposed along the surface of the cathode layer 2 and / or the current collecting member E. Furthermore, since the current collecting bonding layer forming sheet J0 can be adhered to the cathode layer 2 and / or the current collecting member E, the surface 22 of the uneven cathode layer 2 and / or the convex surface E11 of the current collecting member E and Adhesiveness with the surface of the uneven | corrugated current collection joining layer formation sheet J0 can be made higher. The conductive metal oxide particles in the current collecting bonding layer forming sheet J0 can easily enter the cathode layer surface 22 and / or the concave portion of the convex surface E11. When the conductive metal oxide particles and the component particles forming each surface 22 of the cathode layer 2 and / or the convex surface E11 of the current collecting member E are close to each other, the interaction between the two particles is facilitated. Adhesiveness between them increases, and the gap at the contact interface between the cathode layer 2 and / or the current collecting member E and the current collecting bonding layer forming sheet J0 is reduced. Even after the baking step, the state in which there are few voids is maintained, the bonding strength between the cathode layer 2 and / or the current collecting member E and the current collecting bonding layer J is increased, and the increase in contact resistance is suppressed. Therefore, the power generation performance of the SOFC cell can be improved.

  Furthermore, in 1st embodiment, the current collection joining layer J is formed using the sheet | seat J0 for current collection joining layers formed in a sheet form by binding a conductive metal oxide with an organic binder, Adhesion aid A contains α-terpineol, which is a solvent that can dissolve the organic binder.

  Therefore, the current collecting bonding layer J is formed by using a bonding layer forming sheet formed by binding a conductive metal oxide with an organic binder into a sheet shape, and the adhesion auxiliary agent A includes an organic binder. Since α-terpineol, which is a soluble solvent, is contained, adhesion when the cathode layer 2 or / and the current collecting member E and the current collecting bonding layer forming sheet J0 are superposed can be improved. That is, when the solvent in the adhesion auxiliary agent A acts on the organic binder in the current collecting bonding layer forming sheet J0 to dissolve the organic binder, the surface of the current collecting bonding layer forming sheet J0 (upper surface J0e, lower surface J02). ) Wettability and adhesion of the bonding surface can be improved. In this state, the current collecting bonding layer forming sheet J0 is heat-treated to be baked, so that an ohmic resistance is formed at the bonding interface with the cathode layer 2 bonded to the current collecting bonding layer J and / or the bonding interface with the current collecting member E. Can be suppressed more reliably.

  Further, by using α-terpineol as the adhesion aid A, flexibility can be easily given to the current collecting bonding layer forming sheet J0. As shown in the Examples, the power generation performance of the fuel cell can be improved by using α-terpineol. A terpineol-based solvent having the same monoterpene alcohol skeleton as terpineol is considered to have the same effect.

  Further, by using a conductive paste in which a conductive metal oxide powder is dispersed in a solvent together with an organic binder as the adhesion assistant A, the cathode layer 2 and the current collecting bonding layer forming sheet J0 and / or the current collecting member The adhesiveness between E and the current collecting bonding layer forming sheet J0 can be further improved. Flexibility can be easily given to the current collecting bonding layer forming sheet J0. Therefore, the power generation performance of the fuel cell can be improved more reliably. In addition, since it is sufficient to apply a thin conductive paste used as an adhesion aid, there is less risk of cracks, voids, and the like occurring in the conductive paste itself due to heating in the baking process.

  In addition, since the conductive paste contains LSC as the conductive metal oxide, as shown in the examples, by using the conductive paste of LSC as the adhesion aid A, the power generation performance of the fuel cell can be reliably ensured. Can be increased. When the conductive oxide in the current collecting bonding layer J also contains LSC as a main component, the same metal oxide is contained, so that a power generation action is generated between the current collecting bonding layer J and the conductive paste. It is preferable that there is basically no possibility of an unexpected interaction to be hindered (for example, the bonding strength is reduced and the contact resistance is increased due to different expansion coefficients).

  The current collecting bonding layer J is formed using a current collecting bonding layer forming sheet J0 mainly composed of LSC as a conductive metal oxide. LSC is a metal oxide that does not contain expensive rare metals, has a low environmental impact, is stable in the atmosphere, and can be used even under the operating (high) temperature of SOFC. Thus, it is known as a compound exhibiting high conductivity. Therefore, when practicality is considered, the ohmic resistance loss of the current collecting bonding layer itself can be preferably suppressed comprehensively.

<< Second Embodiment >>
[SOFC cell]
Next, the configuration of the SOFC cell 200 according to the SOFC cell manufacturing method of the second embodiment will be described with reference to FIG. The SOFC cell 200 according to the second embodiment is mainly different from the SOFC cell 100 according to the first embodiment in that a cylindrical single cell C2 is used, whereas the flat single cell C is used. Hereinafter, a description will be given focusing on differences from the SOFC cell 100 of the first embodiment.

  FIG. 10 is a view showing a cylindrical SOFC cell 200 of the second embodiment. As shown in the figure, a cylindrical SOFC cell 200 includes a plurality of cylindrical single cells C2 whose outer electrode is the cathode layer 21 and whose inner electrode is the anode layer 11, and between the cylindrical single cells C2 that are electrically adjacent to each other. Disposed so as to face the cathode layer 21 of the cylindrical single cell C2 so as to electrically connect the anode layer 11 of the cylindrical single cell C2 on one side and the cathode layer 21 of the cylindrical single cell C2 on the other side. The current collecting member E20 is provided between the cathode layer 21 of the other cylindrical unit cell C2 and the current collecting member E20, and the cathode layer 21 and the current collecting member E20 are joined and electrically connected. A current collecting bonding layer J2. The SOFC cell 200 is formed by laminating a substantially cylindrical current collecting member E20 that covers substantially the entire outer peripheral surface of the cylindrical single cell C2 and is opposed to each other along the radial direction outside the outer peripheral surface of the cylindrical single cell C2. In addition, a cylindrical current collecting bonding layer J2 is similarly laminated along the radial direction between the inner peripheral surface of the current collecting member E20 and the outer peripheral surface of the cylindrical single cell C2.

(Cylindrical single cell)
The cylindrical single cell C <b> 2 is a cell body that generates power as a fuel cell in the SOFC cell 200. The cylindrical single cell C2 includes an anode layer 11 that is an inner electrode, an electrolyte layer 31, and a cathode layer 21 that is an outer electrode, and these are formed in a layered manner. The anode layer 11 is formed in a long cylindrical shape, and the fuel gas (H ₂ ) flows from one end side (lower side in the drawing) to the other end side (upper side in the drawing). The cathode layer 21 is laminated on the outside of the anode layer 11 and is provided in an oxidant gas (air) atmosphere. The oxidant gas flows from one end side (lower side in the drawing) to the other end side (upper side in the drawing). The electrolyte layer 31 is formed between the anode layer 11 and the cathode layer 21. That is, each of the plurality of cylindrical single cells C <b> 2 is formed in order of the anode layer 11, the electrolyte layer 31, and the cathode layer 21 from the inside. The cylindrical single cell C2 may be formed in the order of the cathode layer 21, the electrolyte layer 31, and the anode layer 11 from the inside. Further, an intermediate layer may be provided between the electrolyte layer 31 and the cathode layer 21 as in the first embodiment.

(Current collector)
The substantially cylindrical current collecting member E <b> 20 is mounted so as to face the outside of the cathode layer 21. The current collecting member E20 attached to the left cylindrical single cell C2 receives electrons generated in the anode layer 11 of the right cylindrical single cell C2 via a predetermined connecting member 50. The current collecting member E20 forms a path for moving received electrons toward the cathode layer 21 of the left cylindrical single cell C2. The circumferential wall of the substantially cylindrical current collecting member E20 is provided with a slit E201 penetrating along the axial direction so that the current collecting member E20 can be expanded in the radial direction as a whole and opened in the circumferential direction. Is formed. In addition, the peripheral wall of the current collecting member E20 is provided with slits E202 having a long hole shape along the circumferential direction, and a large number of slits E202 are continuously formed over substantially the entire length along the axial direction. Yes. These slits E201 and E202 are provided in order to efficiently supply the oxidant gas to the surface of the cathode layer 21 of the cylindrical single cell in a state where the current collecting member E20 is mounted on the cylindrical single cell C2. .

(Current collector bonding layer)
The current collecting bonding layer J2 is a layer for bonding the current collecting member E20 and the cylindrical single cell C2, and substantially the entire inner peripheral surface excluding the slits E201 and E202 of the current collecting member E20 and the substantially entire outer periphery of the cathode layer 21. Both are joined in a state of being stacked so as to be in contact with the surface and sandwiched therebetween. The current collecting bonding layer J2 is formed of a conductive material that electrically connects the current collecting member E20 and the cathode layer 21 to supply electrons collected by the current collecting member E20 to the cathode layer 21. Relay. Further, the current collecting bonding layer J2 is formed by using a current collecting bonding layer forming sheet J20 which is mainly formed of a conductive metal oxide and is formed in a sheet shape. The current collecting bonding layer forming sheet J20 is formed in a substantially rectangular flat plate shape so as to cover and overlap almost the entire outer peripheral surface of the cathode layer 21.

[Manufacture of SOFC cells]
Next, the manufacturing method of the SOFC cell 200 of the above-described second embodiment will be described focusing on differences from the first embodiment. Also in the second embodiment, as in the first embodiment, a preparation step for producing a cylindrical single cell C2 that is a main body of the SOFC cell 200, and a current collector bonding layer formation between the cathode layer 21 and the current collector E20 The current collecting bonding layer forming sheet disposing step for providing the sheet J20 and the baking step for baking the current collecting bonding layer forming sheet J20 to form the current collecting bonding layer J2 are performed. Similarly to the first embodiment, in the current collecting bonding layer forming sheet disposing step, between the cathode layer 21 and the current collecting bonding layer forming sheet J20 or the current collecting bonding layer forming sheet J20 and the current collecting sheet. The current collecting bonding layer forming sheet J20 can be deformed between at least one of the electric members E20 and the cathode layer 21 or / and the current collecting member E20 and the current collecting bonding layer forming sheet J20. In addition to this characteristic step, it can be produced in the same manner as in the conventionally known SOFC cell production method.

  In the current collector bonding layer forming sheet disposing step, in the SOFC 100 of the first embodiment, the flat plate current collector bonding is performed in such a manner that the flat plate cathode layer 21 and the current collecting member E20 overlap almost the entire surface. The layer forming sheet J0 was laminated, but in the SOFC 200 of the second embodiment, the substantially rectangular current collecting bonding layer forming sheet J20 is wound around the entire outer peripheral surface of the cylindrical cathode layer 21, and the substantially entire peripheral surface is wound. It differs in that it is laminated and manufactured so as to overlap. For example, in the SOFC cell 200, after applying a close adhesion agent (not shown) to the outer peripheral surface of the cathode layer 21, the current collecting bonding layer forming sheet J20 is bonded to the cathode layer 21, and the close adhesion auxiliary agent is formed on the inner peripheral surface side. The current collecting member E20 coated with (not shown) is mounted on the outer periphery of the current collecting bonding layer forming sheet J20.

  As described above, the SOFC 200 (cylindrical fuel cell) of the second embodiment is laminated on one side of the electrolyte layer 31 formed in a cylindrical shape and the inside and outside of the electrolyte layer 31, and the fuel gas is on one end side. An anode layer 11 that flows from the other end side to the other end side, a cathode layer 21 that is laminated on either the inner side or the outer side of the electrolyte layer 31 and in which an oxidant gas flows from one end side to the other end side; A current collecting member E20 that is electrically connected to face the cathode layer 21 and supplies electrons to the cathode layer 21, and is provided between the cathode layer 21 and the current collecting member E20. The cathode layer 21 and the current collecting member E20 And a current collecting bonding layer J2 which is formed into a sheet shape with a conductive metal oxide as a main component. Using J20 It is formed.

According to the second embodiment, the invention of the manufacturing method according to the SOFC cell 100 of the first embodiment is an invention grasped from the viewpoint of the cylindrical fuel cell, and has the same effects. The current collecting bonding layer J2 is formed by using the current collecting bonding layer forming sheet J20 which is mainly formed of a conductive metal oxide and formed into a sheet shape, and basically does not contain a solvent in the components. Therefore, it can suppress that a crack, a space | gap, a sink mark etc. arise in the sheet | seat J20 for current collection joining layer formation by heating. The bonding strength between the cathode layer 21 and / or the current collecting member E20 and the current collecting bonding layer J2 is increased, and an increase in contact resistance is suppressed. Therefore, the power generation performance of the cylindrical fuel battery cell can be enhanced.
In addition, since the cylindrical single cell C2 is cylindrical, the difficulty of disposing the current collecting bonding layer forming sheet J20 having a certain thickness between the cathode layer 21 and the current collecting member E20 is a flat SOFC cell. Higher than 100. This is because in the case of a cylindrical shape, it is more difficult to apply pressure along the stacking direction than a flat plate type. In particular, the workability of disposing the current collecting bonding layer forming sheet J20 having a certain thickness along the cylindrical peripheral surface and in a close contact state is deteriorated. The SOFC cell 200 of the second embodiment can be easily obtained by producing according to the production method of the first embodiment, by a simple production method with an adhesion aid.

C ... single cell, C2 ... cylindrical single cell, E, E20 ... current collecting member, J, J2 ... current collecting bonding layer, J0, J20 ... current collecting bonding layer forming sheet, 1, 11 ... anode layer, 2, 21 ... cathode layer, 3, 31 ... electrolyte layer, 100 ... SOFC cell (fuel cell), 200 ... SOFC cylindrical cell (cylindrical fuel cell).

Claims (6)

An electrolyte layer, an anode layer disposed on one side of the electrolyte layer and in a fuel gas atmosphere, a cathode layer disposed on the other side of the electrolyte layer and in an oxidant gas atmosphere, and facing the cathode layer A current collector that is electrically connected and supplies electrons to the cathode layer; and is provided between the cathode layer and the current collector, and joins and electrically connects the cathode layer and the current collector. A current collecting junction layer to be connected,
The current collecting bonding layer is a manufacturing method of a fuel cell formed by using a sheet for collecting current collecting bonding layer formed in a sheet shape with a conductive metal oxide as a main component,
When providing the current collecting bonding layer forming sheet between the cathode layer and the current collecting member, between the cathode layer and the current collecting bonding layer forming sheet, or for the current collecting bonding layer forming The current collecting bonding layer forming sheet can be deformed between at least one of the sheet and the current collecting member, and the cathode layer and / or the current collecting member and the current collecting bonding layer A current collecting bonding layer forming sheet disposing step for attaching a close adhesion auxiliary agent that closely contacts the forming sheet;
After the step of disposing the current collecting bonding layer forming sheet, heating is performed while maintaining a close contact state between the cathode layer and / or the current collecting member and the current collecting bonding layer forming sheet. A baking step of forming a layer and joining the cathode layer and the current collector;
The manufacturing method of the fuel cell which has these.   The method for producing a fuel cell according to claim 1, wherein the adhesion aid is a terpineol solvent.   The method for producing a fuel cell according to claim 1, wherein the adhesion assistant is a conductive paste in which a conductive metal oxide powder is dispersed in a solvent together with an organic binder. The method for producing a fuel cell according to claim ₃ , wherein the conductive paste contains lanthanum strontium cobaltite (LaSrCoO ₃ ) as the conductive metal oxide. The current collecting bonding layer is formed by using the current collecting bonding layer forming sheet containing lanthanum strontium cobaltite (LaSrCoO ₃ ) as a main component as the conductive metal oxide. A method for producing a fuel cell according to one item. An electrolyte layer formed in a cylindrical shape, an anode layer that is laminated on either the inner side or the outer side of the electrolyte layer, and in which fuel gas flows from one end side to the other end side, and the inner side of the electrolyte layer And a cathode layer laminated on either side of the outer side and an oxidant gas flowing from the one end side toward the other end side, and electrically connected to face the cathode layer, and electrons are supplied to the cathode layer. A current collecting member to be supplied; and a current collecting joint layer provided between the cathode layer and the current collecting member, for joining and electrically connecting the cathode layer and the current collecting member,
The said current collection joining layer is a cylindrical fuel cell formed using the sheet | seat for current collection joining layer formation which formed the electroconductive metal oxide as a main component and was formed in the sheet form.

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