JP2023023049A - Electrochemical reaction single cell and method of manufacturing the same - Google Patents

Abstract

To suppress delamination of a specific electrode from a metal support body, in an electrochemical reaction single cell.SOLUTION: An electrochemical reaction single cell comprises: an electrolyte layer; a fuel electrode and an air electrode opposed to each other in a first direction while interposing the electrolyte layer; and a metal support body located on an opposite side to the electrolyte layer, of a specific electrode, which is one of the fuel electrode and the air electrode, having a plurality of through-holes penetrating in the first direction. The specific electrode comprises an electrode hole interior located inside a specific through-hole, which is at least one of the plurality of through-holes. In at least one cross section along the first direction of the electrochemical reaction single cell, when surface roughness of a first portion including an end at the specific electrode side, of a pair of outlines that defines the specific through-hole on the metal support body, is defined as A1 (μm), and surface roughness of a second portion continuous to the first portion at an opposite side to the specific electrode, of the outlines, is defined as A2 (μm), a numerical expression: A1>A2 is satisfied. The electrode hole interior is in contact with at least a part of the first portion of the metal support body.SELECTED DRAWING: Figure 6

Description

The technology disclosed by this specification relates to an electrochemical reaction single cell and a method for manufacturing an electrochemical reaction single cell.

A solid oxide fuel cell (hereinafter referred to as "SOFC") is known as one type of fuel cell that generates power using an electrochemical reaction between hydrogen and oxygen. A fuel cell single cell (hereinafter simply referred to as "single cell"), which is a structural unit of SOFC, has an electrolyte layer containing a solid oxide and a predetermined direction (hereinafter referred to as "first direction") across the electrolyte layer. .) with an anode and an air electrode facing each other.

As one form of a single cell, a metal-supported single cell is known (see, for example, Patent Document 1). A metal-supported single cell has a metal support disposed on the side opposite to the electrolyte layer with respect to one of the fuel electrode and the air electrode (hereinafter referred to as "specific electrode"). Supports other parts of the cell (such as the electrolyte layer). In general, metal-supported single cells are less likely to crack due to thermal shock and have higher startability than other types of single cells (for example, fuel electrode-supported cells).

In a metal-supported single cell, a plurality of through-holes extending from one surface of the metal support to the other surface are formed in the metal support in order to pass the reaction gas used for power generation. The plurality of through holes are positioned so as to overlap the specific electrodes when viewed from the first direction. In a conventional metal-supported single cell, the surface of the metal support that defines the through-hole (hereinafter referred to as the “inner surface of the hole”) has a uniform surface roughness. (hereinafter referred to as "inside the pore") is in contact with the pore inner surface of the metal support having such surface roughness.

JP-A-2005-93262

In the conventional metal-supported single cell described above, when a force (a force substantially parallel to the first direction) is applied to separate the metal support and the specific electrode, the specific electrode may be separated from the metal support. There is

Such problems are also common to electrolytic single cells, which are structural units of solid oxide electrolytic cells (hereinafter referred to as "SOEC") that generate hydrogen using the electrolysis reaction of water. It is a problem. In this specification, the fuel cell single cell and the electrolysis single cell are collectively referred to as an electrochemical reaction single cell.

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) The electrochemical reaction single cell disclosed in the present specification includes an electrolyte layer, a fuel electrode and an air electrode facing each other in a first direction with the electrolyte layer interposed therebetween, and the fuel electrode and the air electrode. A metal support located on the side opposite to the electrolyte layer with respect to one specific electrode, and a plurality of metal supports penetrating in the first direction at a position overlapping the specific electrode when viewed in the first direction and a metal support having through holes, wherein the specific electrode has an electrode hole inside located in at least one specific through hole of the plurality of through holes, and the electrochemical In a specific cross section that is at least one cross section of the reaction unit cell along the first direction, of a pair of specific contour lines that define the specific through-hole of the metal support, the Let A1 (μm) be the surface roughness of the first portion including the end on the side of the specific electrode, and the surface roughness of the second portion of the specific contour line that is continuous with the first portion on the side opposite to the specific electrode. is A2 (μm), the formula: A1>A2 is satisfied, and the inside of the electrode hole is in contact with at least a part of the first portion of the metal support.

In the present electrochemical reaction single cell, by satisfying A1>A2, when a force (a force substantially parallel to the first direction) separating the metal support and the specific electrode acts, the inside of the electrode hole becomes the metal support. (the contour line defining the through-hole of the metal support) of the first portion (the portion including the end on the side of the specific electrode) to effectively function as an anchor. Therefore, according to the present electrochemical reaction single cell, compared with the configuration in which A1 and A2 are equal, of the first directions in the specific electrode and the metal support, the direction in which the specific electrode and the metal support separate can be suppressed, and in turn, peeling of the specific electrode from the metal support can be suppressed.

Furthermore, in this electrochemical reaction single cell, by satisfying A1>A2, the flow along the second portion of the specific contour line in the through hole of the metal support compared to the configuration in which A1 and A2 are equal It is possible to improve the flowability of the reaction gas.

As is clear from the above description, according to the present electrochemical reaction single cell, peeling of the specific electrode from the metal support can be suppressed compared to the configuration in which A1 and A2 are equal, and It is possible to improve the flowability of the reaction gas passing through the through-holes of the metal support, thereby improving the performance of the electrochemical reaction single cell.

(2) The electrochemical reaction single cell may have a configuration that satisfies the formula: A1/A2≧1.2. According to the present electrochemical reaction single cell, it is possible to more effectively suppress positional deviation in the first direction between the specific electrode and the metal support in the direction in which the specific electrode and the metal support separate, As a result, peeling of the specific electrode from the metal support can be suppressed more effectively.

(3) In the above electrochemical reaction single cell, the metal support comprises a first metal member having the first portion of the specific contour and a second metal member having the second portion of the specific contour. It is good also as a structure containing a member.

In a configuration in which the metal support is made of a single metal member, surfaces having two different types of surface roughness (A1, A2) are formed on the single metal member (and , for each portion defining the same through-hole), it is not easy to process to achieve such surface roughness. On the other hand, in the present electrochemical reaction unit cell, which is configured to include the first metal member having the first portion of the specific contour line and the second metal member having the second portion of the specific contour line, 1 Each metal member (first metal member, second metal member) is processed to have different surface roughness (A1 or A2), and only by assembling them, two different surface roughnesses (A1, A2) can be obtained. A metal support with A2) can be made. Therefore, the present electrochemical reaction single cell having such a configuration can be easily manufactured.

(4) In the above electrochemical reaction single cell, in the specific cross section, the specific through hole may have a space on the side opposite to the electrolyte layer in the first direction inside the electrode hole.

In the present electrochemical reaction single cell, as described above, by satisfying A1>A2, the separation of the specific electrode from the metal support can be suppressed, and the reaction passing through the through holes of the metal support can be suppressed. It is possible to improve gas flowability, thereby improving the performance of the electrochemical reaction single cell. According to the present electrochemical reaction single cell, although such an effect can be obtained, as described above, the through-hole of the metal support is a space on the opposite side of the electrolyte layer in the first direction inside the electrode hole. By having the through-hole of the metal support, compared to a configuration in which the through-hole does not have the space (for example, a configuration in which the entire through-hole is filled with the specific electrode), the flow of the reaction gas through the through-hole can be improved, and thus the performance of the electrochemical reaction single cell can be improved.

(5) In the electrochemical reaction single cell, in the specific cross section, a joint portion where the first portion of the specific contour line of the metal support and the specific electrode are joined (hereinafter referred to as “first joint The length in the first direction of the second portion of the specific contour line of the metal support and the specific electrode are joined to the joint portion (hereinafter referred to as the “second joint (referred to as "part") in the first direction. According to the present electrochemical reaction single cell, it is possible to more effectively suppress positional deviation in the first direction between the specific electrode and the metal support in the direction in which the specific electrode and the metal support separate, As a result, peeling of the specific electrode from the metal support can be suppressed more effectively.

(6) In the method for producing an electrochemical reaction single cell, a first step of preparing the metal support and a paste material for forming the specific electrode; a second step of disposing, the second step of pouring from the first portion side to the second portion side into the specific through-hole formed in the metal support; and curing at least the paste-like material. Thus, the specific electrode having the inside of the electrode hole and the metal support are provided, and the specific through hole forms a space inside the electrode hole on the side opposite to the electrolyte layer in the first direction. and a third step of obtaining a member having.

The metal support in the manufacturing method of the present electrochemical reaction single cell satisfies A1>A2 as described above. In other words, the surface roughness (A1) of the first portion (the portion including the end on the side of the specific electrode) of the specific contour line of the metal support (the contour line defining the through-hole of the metal support) is relatively high, The surface roughness (A2) of the second portion of the specific contour line of the metal support is relatively low. Therefore, compared to the manufacturing method in which A1 and A2 are equivalent, in the second step, the paste-like material is poured from the first portion side toward the second portion side into the through holes formed in the metal support. However, the paste-like material tends to stay in the first portion with high surface roughness, while the paste-like material does not easily stay in the second portion with low surface roughness (A2). After such a second step, the paste material is cured in a third step ST13. Therefore, according to the present manufacturing method, compared with the manufacturing method in which A1 and A2 are equal, the through hole of the metal support is easily or reliably positioned on the opposite side of the electrolyte layer in the first direction inside the electrode hole. Spatial configurations can be realized (manufactured).

The technology disclosed in the present specification can be implemented in various forms. It is possible to implement it in the form of

1 is a perspective view showing the external configuration of a fuel cell stack 100 according to this embodiment; FIG. Explanatory drawing showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position II-II in FIG. Explanatory drawing showing the YZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. Explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory diagram showing the YZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. FIG. 6 is an explanatory diagram showing an enlarged YZ cross-sectional configuration of a portion (X1 section in FIG. 5) of the single cell 110; 4 is a flow chart showing a method of manufacturing a single cell 110. FIG. FIG. 5 is an explanatory diagram showing performance evaluation results;

A. Embodiment:
A-1. Configuration of fuel cell stack 100:
FIG. 1 is a perspective view showing the external configuration of the fuel cell stack 100 in this embodiment, and FIG. 2 is an explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position II-II in FIG. FIG. 3 is an explanatory diagram showing the YZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. Each figure shows mutually orthogonal XYZ axes for specifying directions. In this specification, for the sake of convenience, the positive Z-axis direction is referred to as the upward direction, and the negative Z-axis direction is referred to as the downward direction. may be installed. The same applies to FIG. 4 and subsequent figures.

The fuel cell stack 100 includes a plurality of (seven in this embodiment) fuel cell power generation units (hereinafter simply referred to as “power generation units”) 102 and a pair of end plates 104 and 106 . The seven power generation units 102 are arranged side by side in a predetermined arrangement direction (the Z-axis direction in this embodiment). A pair of end plates 104 and 106 are arranged so as to sandwich an aggregate composed of seven power generation units 102 from above and below. The arrangement direction (Z-axis direction) is an example of a first direction in the scope of claims.

A plurality of holes (eight in this embodiment) penetrating in the Z-axis direction are formed in the peripheral edge portion around the Z-axis direction of each layer (the power generating unit 102, the end plates 104 and 106) constituting the fuel cell stack 100. Corresponding holes formed in each layer communicate with each other in the Z-axis direction to form through-holes 108 extending in the Z-axis direction from one end plate 104 to the other end plate 106 . In the following description, the holes formed in each layer of the fuel cell stack 100 to form the through holes 108 may also be referred to as the through holes 108 .

A bolt 22 extending in the Z-axis direction is inserted through each through-hole 108 , and the fuel cell stack 100 is fastened by the bolt 22 and nuts 24 fitted on both sides of the bolt 22 . As shown in FIGS. 2 and 3, an insulating sheet 26 is interposed between the nut 24 and each of the end plates 104, 106 (or a gas passage member 27 to be described later).

A space is secured between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each through hole 108 . As shown in FIGS. 1 and 2, the space formed by one bolt 22 (bolt 22A) and the through-hole 108 through which the bolt 22A is inserted allows the oxidizing gas OG (for example, air) is introduced, and functions as an air electrode side gas supply manifold 161, which is a gas flow path for supplying the oxidant gas OG to the air chamber 166 of each power generation unit 102, and the other one bolt 22 (bolt 22B). The space formed by the through-hole 108 through which the bolt 22B is inserted serves as an air electrode for discharging the oxidant off-gas OOG, which is the gas discharged from the air chamber 166 of each power generation unit 102, to the outside of the fuel cell stack 100. It functions as a side gas exhaust manifold 162 . Further, as shown in FIGS. 1 and 3, the space formed by another bolt 22 (bolt 22D) and the through hole 108 through which the bolt 22D is inserted is filled with fuel gas from the outside of the fuel cell stack 100. FG (for example, hydrogen-rich gas) is introduced, and functions as a fuel electrode side gas supply manifold 171 that supplies the fuel gas FG to the fuel chamber 176 of each power generation unit 102, and the other one bolt 22 (bolt 22E). The space formed by the through hole 108 through which the bolt 22E is inserted is the fuel electrode side through which the fuel off-gas FOG, which is the gas discharged from the fuel chamber 176 of each power generation unit 102, is discharged to the outside of the fuel cell stack 100. It functions as a gas exhaust manifold 172 .

Four gas passage members 27 are provided in the fuel cell stack 100 . Each gas passage member 27 has a hollow tubular body portion 28 and a hollow tubular branch portion 29 branched from a side surface of the main body portion 28 . A hole in the branch portion 29 communicates with a hole in the main body portion 28 . The holes of the body portion 28 of each gas passage member 27 communicate with manifolds 161 , 162 , 171 and 172 provided at the installation positions of the gas passage members 27 .

(Configuration of end plates 104, 106)
The pair of end plates 104 and 106 are plate-shaped conductive members substantially orthogonal to the Z-axis direction, and are made of stainless steel, for example. One end plate 104 is arranged above the uppermost power generation unit 102 and is electrically connected to the power generation unit 102 . The other end plate 106 is arranged below the lowest power generation unit 102 and is electrically connected to the power generation unit 102 . The upper end plate 104 functions as the positive side output terminal of the fuel cell stack 100 , and the lower end plate 106 functions as the negative side output terminal of the fuel cell stack 100 .

(Configuration of power generation unit 102)
4 is an explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. 2, and FIG. FIG. 3 is an explanatory diagram showing a YZ cross-sectional configuration of two power generation units 102;

As shown in FIGS. 4 and 5, the power generation unit 102 includes a fuel cell single cell (hereinafter referred to as "single cell") 110, a separator 120, an air electrode side frame member 130, and an air electrode side current collector. 134 , an anode-side frame member 140 , an anode-side current collector 144 , and a pair of interconnectors 150 . Peripheral portions of the separator 120, the air electrode side frame member 130, the fuel electrode side frame member 140, and the interconnector 150 are formed with holes corresponding to the through holes 108 through which the bolts 22 are inserted.

The interconnector 150 is a plate-shaped conductive member substantially perpendicular to the Z-axis direction, and is made of, for example, stainless steel. The interconnector 150 ensures electrical continuity between the power generating units 102 and prevents mixing of reaction gases between the power generating units 102 . In this embodiment, when two power generation units 102 are arranged adjacently, one interconnector 150 is shared by the two adjacent power generation units 102 . That is, the upper interconnector 150 in a certain power generation unit 102 is the same member as the lower interconnector 150 in another power generation unit 102 adjacent to the upper side of the power generation unit 102 . In addition, the power generation unit 102 located at the top in the fuel cell stack 100 does not have the upper interconnector 150, and the power generation unit 102 located at the bottom does not have the lower interconnector 150 (FIGS. 2 and 3). See Figure 3).

The unit cell 110 includes an electrolyte layer 112, and an air electrode 114 and a fuel electrode 116 facing each other in the Z-axis direction with the electrolyte layer 112 interposed therebetween. The unit cell 110 further includes a metal support 180 arranged on the opposite side (lower side) of the electrolyte layer 112 with respect to the fuel electrode 116 (more specifically, the base 117 of the fuel electrode 116 described later).

The metal support 180 is a flat plate-shaped conductive member substantially perpendicular to the Z-axis direction, and is made of metal (for example, stainless steel). The metal support 180 supports other components in the single cell 110 (such as the electrolyte layer 112). As described above, the unit cell 110 of the present embodiment is a so-called metal support type unit cell in which the mechanical strength of the unit cell 110 is ensured by the metal support 180 . A metal-supported single cell is less prone to cracking due to thermal shock and has a higher startability than other types of single cells (for example, a fuel electrode-supported type). The metal support 180 is formed with a plurality of through holes 50 for passing the fuel gas FG (see FIG. 6). The plurality of through holes 50 penetrate in the Z-axis direction from the upper surface (upper surface S11 described later) to the lower surface (lower surface S22 described later) of the metal support 180 .

The electrolyte layer 112 is a plate-shaped member substantially orthogonal to the Z-axis direction, and is a dense layer. In this embodiment, the electrolyte layer 112 is formed so as to continuously cover the upper surface of the fuel electrode 116 and the region of the upper surface of the metal support 180 that is not covered with the fuel electrode 116 . there is The electrolyte layer 112 is made of solid oxide such as YSZ (yttria-stabilized zirconia). Thus, the single cell 110 of this embodiment is a solid oxide fuel cell (SOFC) using a solid oxide as an electrolyte. The air electrode 114 is a flat plate-shaped member substantially orthogonal to the Z-axis direction, and is a porous layer. The air electrode 114 is made of, for example, a perovskite oxide (for example, LSCF (lanthanum strontium cobalt iron oxide)). The fuel electrode 116 is a flat plate-shaped member substantially orthogonal to the Z-axis direction, and is a porous layer. The fuel electrode 116 is made of, for example, a cermet made of Ni and oxide ion conductive ceramic particles (eg, YSZ). In this embodiment, the fuel electrode 116 corresponds to a specific electrode in the claims.

The separator 120 is a frame-like member having a substantially rectangular hole 121 extending in the Z-axis direction near its center, and is made of stainless steel, for example. A portion of the separator 120 surrounding the hole 121 is joined to the peripheral portion of the unit cell 110 (electrolyte layer 112) by a joining portion 124 containing brazing material, for example. Separator 120 separates air chamber 166 facing air electrode 114 and fuel chamber 176 facing fuel electrode 116 .

The air electrode-side frame member 130 is a frame-shaped member having a substantially rectangular hole 131 penetrating in the Z-axis direction near the center, and is made of an insulator such as mica. The hole 131 of the cathode-side frame member 130 constitutes an air chamber 166 facing the cathode 114 . A pair of interconnectors 150 included in the power generation unit 102 are electrically insulated by the cathode-side frame member 130 . The air electrode side frame member 130 has an air electrode side gas supply communication passage 132 that communicates between the air electrode side gas supply manifold 161 and the air chamber 166, and an air electrode side gas discharge manifold 162 that communicates with the air chamber 166. An air electrode side gas discharge communication channel 133 is formed.

The fuel electrode-side frame member 140 is a frame-shaped member having a substantially rectangular hole 141 penetrating in the Z-axis direction near the center, and is made of stainless steel, for example. A hole 141 of the anode-side frame member 140 constitutes a fuel chamber 176 facing the anode 116 . In the fuel electrode side frame member 140, a fuel electrode side gas supply communication passage 142 that communicates between the fuel electrode side gas supply manifold 171 and the fuel chamber 176, and a fuel electrode side gas discharge manifold 172 that communicates with the fuel chamber 176 are provided. A fuel electrode side gas discharge communication channel 143 is formed.

The air electrode side current collector 134 is composed of a plurality of substantially quadrangular prism-shaped current collector elements 135 arranged in the air chamber 166, and is made of, for example, stainless steel. The air electrode side current collector 134 electrically connects the air electrode 114 and the interconnector 150 . However, since the uppermost power generation unit 102 in the fuel cell stack 100 does not have the upper interconnector 150, the air electrode side current collector 134 in the power generation unit 102 is composed of the air electrode 114 and the upper end plate 104 and are electrically connected (see FIGS. 2 and 3). The cathode-side current collector 134 and the interconnector 150 may be configured as an integral member.

The fuel electrode side current collector 144 is composed of a plurality of substantially quadrangular prism-shaped current collector elements 145 arranged in the fuel chamber 176, and is made of, for example, stainless steel. The fuel electrode-side current collector 144 electrically connects the metal support 180 and the interconnector 150 . However, since the lowest power generation unit 102 in the fuel cell stack 100 does not have the lower interconnector 150, the fuel electrode side current collector 144 in the power generation unit 102 is formed by the metal support 180 and the lower It is electrically connected to the end plate 106 (see FIGS. 2 and 3). Note that the fuel electrode-side current collector 144 and the interconnector 150 may be configured as an integral member.

A-2. Operation of fuel cell stack 100:
As shown in FIGS. 2 and 4, the oxidant gas OG is supplied from a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the air electrode side gas supply manifold 161. The gas is supplied to the air electrode side gas supply manifold 161 through the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and from the air electrode side gas supply manifold 161 to the air electrode side gas supply communication channel of each power generation unit 102. 132 to air chamber 166 . Further, as shown in FIGS. 3 and 5, the fuel gas FG is supplied from a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the fuel electrode side gas supply manifold 171. , is supplied to the fuel electrode side gas supply manifold 171 through the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and the fuel electrode side gas supply communication flow of each power generation unit 102 is supplied from the fuel electrode side gas supply manifold 171. It is supplied to fuel chamber 176 via passage 142 .

In each power generation unit 102, the oxidant gas OG supplied to the air chamber 166 entered the porous air electrode 114, and the fuel gas FG supplied to the fuel chamber 176 was formed on the metal support 180. When entering the porous fuel electrode 116 through the plurality of through-holes 50 , electricity is generated by an electrochemical reaction between oxygen contained in the oxidant gas OG and hydrogen contained in the fuel gas FG in the single cell 110 . This power generation reaction is an exothermic reaction. In each power generation unit 102, the air electrode 114 of the single cell 110 is electrically connected to one interconnector 150 through the air electrode side current collector 134, and the fuel electrode 116 is connected to the metal support 180 and the fuel electrode side. It is electrically connected to the other interconnector 150 via the current collector 144 . Also, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series. Therefore, the electrical energy generated in each power generation unit 102 is taken out from the end plates 104 and 106 that function as output terminals of the fuel cell stack 100 . Since the SOFC generates power at a relatively high temperature (for example, 700° C. to 1000° C.), the fuel cell stack 100 is heated by the heater ( (not shown).

As shown in FIGS. 2 and 4, the oxidant offgas OOG discharged from the air chamber 166 of each power generation unit 102 to the air electrode side gas discharge manifold 162 through the air electrode side gas discharge communication channel 133 is The gas is discharged to the outside of the fuel cell stack 100 from a gas pipe (not shown) connected to the branch portion 29 via the main portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the side gas discharge manifold 162 . be done. Further, as shown in FIGS. 3 and 5, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102 to the fuel electrode side gas discharge manifold 172 through the fuel electrode side gas discharge communication passage 143 is The gas is discharged to the outside of the fuel cell stack 100 from a gas pipe (not shown) connected to the branch portion 29 via the main portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the pole-side gas discharge manifold 172 . be done.

A-3. Detailed configuration of single cell 110:
FIG. 6 is an explanatory view showing an enlarged YZ cross-sectional configuration of a portion (X1 portion in FIG. 5) of the single cell 110. As shown in FIG. The cross section shown in FIG. 6 is an example of a specific cross section in the claims.

(Metal support 180)
As described above, the metal support 180 is formed with a plurality of through holes 50 for passing the fuel gas FG. In the metal support 180, each through-hole 50 penetrates in the Z-axis direction from an upper surface S11 in contact with the fuel electrode 116 (more specifically, a base portion 117 described later) to a lower surface S22 opposite to the upper surface S11. there is Each through-hole 50 is positioned so as to overlap the fuel electrode 116 when viewed in the Z-axis direction.

The metal support 180 has a structure in which two plate members (a first metal member 181 and a second metal member 182) are laminated in the Z-axis direction. The second metal member 182 is arranged below the first metal member 181 and is joined to the first metal member 181 by welding, for example. The thickness of the first metal member 181 and the thickness of the second metal member 182 are substantially the same.

Each through-hole 50 formed in the metal support 180 has an upper portion 51 that includes an opening 53 in the upper surface S11 of the metal support 180 . An upper portion 51 of each through-hole 50 is formed in a first metal member 181 that constitutes the metal support 180 . Each upper part 51 penetrates from the upper surface S11 of the first metal member 181 in contact with the fuel electrode 116 to the lower surface S12 opposite to the upper surface S11.

Each through-hole 50 formed in the metal support 180 has an upper portion 51 and a lower portion 52 communicating with the upper portion 51 . The lower side portion 52 is a portion including the opening 54 in the lower surface of the metal support 180 (the lower surface S22 of the second metal member 182 described later). Each lower part 52 penetrates from the upper surface S21 of the second metal member 182 in contact with the first metal member 181 to the lower surface S22 opposite to the upper surface S21. The outline of the lower portion 52 overlaps the outline of the upper portion 51 when viewed in the Z-axis direction. That is, each through hole 50 is composed of an upper portion 51 and a lower portion 52 .

Hereinafter, in a cross section along the Z-axis direction of the unit cell 110 (for example, the cross section shown in FIG. 6), one of a pair of contour lines defining the through hole 50 of the metal support 180 is referred to as a contour line 501, and the other is referred to as a contour line 501. is called a contour line 502 .

A portion of the outline 501 of the metal support 180 formed by the first metal member 181 is called a first portion 5011 , and a portion formed by the second metal member 182 is called a second portion 5012 . In other words, the first portion 5011 of the contour 501 is the portion of the contour 501 that includes the end on the fuel electrode 116 side, and the second portion 5012 of the contour 501 is the portion of the contour 501 that includes the fuel electrode 116 side. 116 is a portion continuous with the first portion 5011 on the opposite side. The second portion 5012 constitutes the end of the outline 501 opposite to the fuel electrode 116 .

When the surface roughness of the first portion 5011 of the contour 501 of the metal support 180 is A11 (μm) and the surface roughness of the second portion 5012 of the contour 501 is A21 (μm), the The single cell 110 satisfies the formula: A11>A21. A11 and A21 have three significant digits. In this embodiment, any cross section along the Z-axis direction of the unit cell 110 satisfies the formula.

The surface roughness of each portion (the first portion 5011 and the second portion 5012) of the contour line 501 of the metal support 180 is specified, for example, as follows. First, a cross section parallel to the Z-axis direction in the single cell 110 (however, the position where the through hole 50 of the metal support 180 and the fuel electrode 116 appear) is arbitrarily set, and an arbitrary position in the cross section (however, the metal support 180 where the contour line 501 appears), an SEM image (for example, 1000 times magnification) of the fuel electrode 116 is obtained with an SEM (accelerating voltage of 15 kV). In addition, you may use the image in a laser microscope.

In the SEM image, by performing image analysis of the first portion 5011 (or second portion 5012) of the contour 501, the arithmetic mean roughness Ra in the first portion 5011 (or second portion 5012) of the contour 501 Calculate the corresponding surface roughness value. Based on this ratio, the surface roughness of the first portion 5011 (or the second portion 5012) is estimated and identified. The same applies to specifying the surface roughness of the first portion 5021 and the second portion 5022 of the other contour line 502 .

The adjustment of the surface roughness of each part (the first part 5011 and the second part 5012) of the contour line 501 of the metal support 180 is performed, for example, when forming the through holes 50 in the metal support 180 by etching, It can be realized by appropriately changing the etching conditions (type of etchant, etc.).

The configuration of the other contour line 502 is also the same as the configuration of the contour line 501 described above. That is, the configuration of the other contour line 502 is as follows.

When the surface roughness of the first portion 5021 of the contour line 502 is A12 (μm) and the surface roughness of the second portion 5012 of the contour line 502 is A22 (μm), the single cell 110 of the present embodiment is Expression: A12>A22 is satisfied. A12 and A22 have three significant digits. In this embodiment, any cross section along the Z-axis direction of the unit cell 110 satisfies the formula.

(Fuel electrode 116, etc.)
The fuel electrode 116 includes a base portion 117 having a flat plate shape and a plurality of hole interiors 118 . Each hole interior 118 is connected to the base 117 and located within each through hole 50 of the metal support 180 .

Each hole interior 118 of the fuel electrode 116 is located only in the upper portion 51 of each through hole 50 . Each hole interior 118 of the anode 116 is in contact with a first portion 5011,5012 of the contour lines 501,502 of the metal support 180, but is not in contact with a second portion 5011,5012. The first portions 5011 and 5012 of the contour lines 501 and 502 of the metal support 180 are joined to substantially the entirety (the surface of the first metal member 181 defining the through hole 50). Accordingly, the hole interior 118 of the fuel electrode 116 contacts substantially the entirety of the first portions 5011 and 5012 of the contour lines 501 and 502 of the metal support 180 .

Therefore, in the cross section along the Z-axis direction of the unit cell 110 (for example, the cross section shown in FIG. 6), the joint portion where the first portion 5011 of the contour line 501 of the metal support 180 and the fuel electrode 116 are joined is greater than the length in the Z-axis direction of the joint where the second portion 5012 of the contour line 501 of the metal support 180 and the fuel electrode 116 are joined. Furthermore, the length in the Z-axis direction of the joint where the first portion 5021 of the contour 502 of the metal support 180 and the fuel electrode 116 are joined is also the length of the second portion 5022 of the contour 502 of the metal support 180. , and the anode 116 are longer than the length in the Z-axis direction of the joint.

Each through-hole 50 has a space SP on the opposite side of the electrolyte layer 112 in the Z-axis direction inside the hole 118 of the fuel electrode 116 .

In addition, in the present embodiment, the plurality of through holes 50 are arranged over substantially the entire range in which the metal support 180 and the fuel electrode 116 overlap when viewed in the Z-axis direction. Moreover, the shape of each through-hole 50 in the XY cross section of the single cell 110 is circular. The diameter of each through-hole 50 is substantially constant from the position of the opening 53 on the upper surface S11 of the metal support 180 to the position of the opening 54 on the lower surface S22. Also, the diameters of the plurality of through holes 50 are substantially the same.

The reaction gas (fuel gas FG) supplied to the fuel chamber 176 advances through each through-hole 50 (space SP), further advances through the gap of the base 117 of the fuel electrode 116, and is supplied to the reaction field. .

A-4. Manufacturing method of single cell 110:
FIG. 7 is a flow chart showing a method for manufacturing the single cell 110. As shown in FIG.

The single cell 110 can be manufactured, for example, by the following steps. First, a metal support 180 and a paste material for forming the fuel electrode 116 (hereinafter referred to as "fuel electrode paste material") are prepared (ST11). The step of ST11 is an example of the first step in the claims.

The metal support 180 can be produced, for example, as follows. A first metal member 181 and a second metal member 182 that constitute a metal support 180 are prepared, and the upper portions 51 of the through holes 50 are formed in the first metal member 181 by drilling. The lower part 52 of each through-hole 50 is formed in the metal member 182 of . Next, the first metal member 181 and the second metal member 182 are connected so that each upper portion 51 communicates with each lower portion 52 (and the contour line of the upper portion 51 and the lower portion when viewed in the Z-axis direction). A metal support 180 is fabricated by aligning and joining, for example, by welding. Moreover, the fuel electrode paste material can be obtained by preparing various materials.

Next, the fuel electrode paste material is placed on the metal support 180, and further, the first portion 5011 side (upper side) of the contour lines 501 and 502 is applied to the plurality of through holes 50 formed in the metal support 180. from the second portion 5012 side (lower side) (ST12). As a result, the plurality of through holes 50 formed in the metal support 180 are filled with the fuel electrode paste material for forming the hole interiors 118 of the fuel electrode 116 . At this time, each through-hole 50 is filled so that the above-mentioned space (space on the side opposite to the electrolyte layer 112 in the Z-axis direction in the inside 118 of the hole 118 of the fuel electrode 116) SP is formed in each through-hole 50. The filling amount of the fuel electrode paste material is adjusted. The step of ST12 is an example of the second step in the claims.

Next, a fuel electrode paste material for forming the base portion 117 of the fuel electrode 116 is applied to the upper surface S11 of the metal support 180 to form a film. Through the above steps, a laminate including the metal support 180 and the fuel electrode paste material is obtained. The paste-like material for forming the hole interior 118 of the fuel electrode 116 and the paste-like material for forming the base portion 117 may have the same composition, or may have different compositions.

Next, a paste material for forming electrolyte layer 112 is arranged (ST13). That is, a paste-like material for forming the electrolyte layer 112 is prepared, and the paste-like material for forming the base portion 117 of the fuel electrode 116 is coated on the coating film of the fuel electrode paste-like material to form a film.

Next, the laminate produced as described above is fired at a predetermined temperature to harden the above various paste materials (at least the fuel electrode paste materials) (ST14). Thus, by curing various paste-like materials, the fuel electrode 116 and the electrolyte layer 112 are formed, and a laminate including the metal support 180, the fuel electrode 116, and the electrolyte layer 112 is obtained. The step of ST13 is an example of the third step in the claims.

Next, the air electrode 114 is formed (ST15). That is, a paste material for forming the air electrode 114 is prepared and applied onto the electrolyte layer 112 to form a film. By firing the laminate thus produced at a predetermined temperature, the air electrode 114 is formed, and the unit cell 110 described above (the metal support 180, the fuel electrode 116, the electrolyte layer 112, and the air electrode 114 is A single cell 110) comprising:

The order of performing all or part of the step of ST13 (the step of disposing a paste material for forming the electrolyte layer 112) and the step of ST15 (the step of forming the air electrode 114) should be changed to another step (ST11). , ST12, ST14).

A-5. Effect of this embodiment:
As described above, each unit cell 110 constituting the fuel cell stack 100 of the present embodiment includes an electrolyte layer 112, a fuel electrode 116 and an air electrode 114 facing each other in the Z-axis direction with the electrolyte layer 112 interposed therebetween, and a metal support 180 located on the opposite side of the anode 116 from the electrolyte layer 112 . The metal support 180 has a plurality of through holes 50 penetrating in the Z-axis direction at positions overlapping the fuel electrode 116 when viewed in the Z-axis direction. The anode 116 comprises a bore interior 118 located within the through bore 50 . In at least one cross section along the Z-axis direction of the unit cell 110 (hereinafter referred to as "specific cross section"), one of the pair of contour lines (501, 502) defining the through hole 50 of the metal support 180 A11 (μm) is the surface roughness of a first portion 5011 of a certain contour line 501 including the end on the fuel electrode 116 side. When the surface roughness of the second portion 5012 to be used is A21 (μm), the formula: A11>A21 is satisfied. The hole interior 118 of the fuel electrode 116 is in contact with at least a portion of the first portion 5011 of the metal support 180 .

In the single cell 110 of the present embodiment, by satisfying A11>A21, when a force (a force substantially parallel to the Z-axis direction) separating the metal support 180 and the fuel electrode 116 acts, the hole of the fuel electrode 116 The inner portion 118 engages with the first portion 5011 (the portion including the end on the fuel electrode 116 side) of the contour 501 (the contour defining the through hole 50) of the metal support 180 to effectively function as an anchor. Therefore, according to the single cell 110 of the present embodiment, compared to the configuration in which A11 and A21 are equal, the fuel electrode 116 and the metal support 180 It is possible to suppress positional deviation in the direction in which the metal support 180 separates from the metal support 180 , and thus to suppress separation of the fuel electrode 116 from the metal support 180 .

Furthermore, in the unit cell 110 of the present embodiment, by satisfying A11>A21, the second portion 5012 of the outline 501 (the fuel electrode 116 and can improve the flowability of the reactant gas (fuel gas FG) flowing along the portion including the opposite end).

As is clear from the above description, according to the single cell 110 of the present embodiment, separation of the fuel electrode 116 from the metal support 180 can be suppressed as compared with the configuration in which A11 and A21 are equal. Moreover, the flowability of the reaction gas (fuel gas FG) passing through the through-holes 50 of the metal support 180 can be improved, thereby improving the performance of the single cell 110 .

Further, the single cell 110 of the present embodiment satisfies the formula: A11/A21≧1.2. Therefore, according to the unit cell 110 of the present embodiment, the displacement in the Z-axis direction between the fuel electrode 116 and the metal support 180 can be more effectively reduced. In addition, separation of the fuel electrode 116 from the metal support 180 can be suppressed more effectively.

In addition, in the unit cell 110 of the present embodiment, the metal support 180 includes the first metal member 181 having the first portion 5011 of the contour line 501 and the second metal member 181 having the second portion 5012 of the contour line 501. 182 and .

In a configuration where the metal support 180 is made of a single metal member, surfaces having two different types of surface roughness (A11, A21) are formed on the single metal member (and the same (for each portion defining the through-hole 50), it is not easy to process such a surface roughness. On the other hand, the unit cell of the present embodiment includes a first metal member 181 having a first portion 5011 of the contour line 501 and a second metal member 182 having a second portion 5012 of the contour line 501. In 110, one type of surface roughness (A11 or A21) is applied to each metal member (first metal member 181, second metal member 182), and only by assembling them, two different types of surface roughness can be obtained. A metal support 180 can be fabricated with a surface roughness (A11, A21) of . Therefore, the single cell 110 of this embodiment having such a configuration can be easily manufactured.

In addition, in the unit cell 110 of the present embodiment, the through hole 50 has a space SP on the opposite side of the electrolyte layer 112 in the Z-axis direction of the inside 118 of the hole of the fuel electrode 116 in the specific cross section.

In the unit cell 110 of the present embodiment, as described above, by satisfying A11>A21, separation of the fuel electrode 116 from the metal support 180 can be suppressed, and the through hole of the metal support 180 can be suppressed. The flowability of the reactant gas (fuel gas FG) passing through the inside of 50 can be improved, and the performance of the single cell 110 can be improved. According to the single cell 110 of the present embodiment, although such an effect can be obtained, as described above, the through hole 50 is located on the opposite side of the electrolyte layer 112 in the Z-axis direction of the inside 118 of the fuel electrode 116 . By having a space in the through-hole 50, the reactant gas passing through the through-hole 50 ( The flowability of the fuel gas FG) can be improved, and thus the performance of the single cell 110 can be improved.

Further, in the unit cell 110 of the present embodiment, in a specific cross section, a joint portion (hereinafter referred to as “first joint portion ) in the Z-axis direction is the joint portion where the second portion 5012 of the outline 501 of the metal support 180 and the fuel electrode 116 are joined (hereinafter referred to as the “second joint portion”). ) in the Z-axis direction. According to the single cell 110 of the present embodiment, displacement in the Z-axis direction between the fuel electrode 116 and the metal support 180 is more effectively suppressed. As a result, separation of the fuel electrode 116 from the metal support 180 can be suppressed more effectively.

Moreover, the manufacturing method of the single cell 110 of the present embodiment includes a first step ST11, a second step ST12, and a third step ST13. The first step ST11 is a step of preparing the metal support 180 and the paste-like material for forming the fuel electrode 116 . The second step ST12 is a step of placing a paste-like material on the metal support 180 and then pouring it into the through holes 50 formed in the metal support 180 from the first portion 5011 side to the second portion 5012 side. . In the third step ST13, by curing at least the paste-like material, the fuel electrode 116 having the hole inside 118 and the metal support 180 are provided, and the through hole 50 is aligned with the Z axis of the hole inside 118 of the fuel electrode 116. It is a step of obtaining a member having a space SP on the side opposite to the electrolyte layer 112 in the direction.

The metal support 180 in the manufacturing method of the single cell 110 of this embodiment satisfies A11>A21 as described above. In other words, the surface roughness (A11) of the first portion 5011 (the portion including the end on the fuel electrode 116 side) of the contour 501 (the contour defining the through hole 50) of the metal support 180 is relatively high, The surface roughness (A21) of the second portion 5012 (the portion including the end opposite the anode 116) of the contour 501 of the metal support 180 is relatively low. Therefore, when compared with the manufacturing method in which A11 and A21 are equivalent, in the second step ST12, the paste-like material is applied to the through holes 50 formed in the metal support 180 from the first portion 5011 side to the second portion 5012. When poured sideways, the paste-like material tends to stay in the first portion 5011 with a high surface roughness, while the paste-like material does not easily stay in the second portion 5012 with a low surface roughness (A21). . After the second step ST12, the paste material is cured in the third step ST13. Therefore, according to the present manufacturing method, compared with a manufacturing method in which A11 and A21 are equivalent, the through-hole 50 is easily or reliably formed on the opposite side of the electrolyte layer 112 in the Z-axis direction of the hole interior 118 of the fuel electrode 116. It is possible to realize (manufacture) a configuration having a space SP at .

Although the effects of applying the present invention to the configuration relating to the contour line 501 have been described above, the same effects can be obtained by applying the present invention to the configuration relating to the contour line 502 .

A-6. Performance evaluation:
Next, performance evaluation of this embodiment will be described. A plurality of single cell 110 samples having different characteristics were produced, and performance evaluation was performed using the samples ("Evaluation of power generation performance of single cell 110" will be described later as a button cell). FIG. 8 is an explanatory diagram showing performance evaluation results.

As shown in FIG. 8, six samples (samples SP1 to SP6) of the single cell 110 were used for this performance evaluation.

In each sample, the surface of the metal support 180 (first metal member 181) defining the upper portion 51 of the through-hole 50 had a uniform surface roughness. That is, in a cross section along the Z-axis direction of the unit cell 110 (for example, the cross section shown in FIG. 6), the surface roughness A11 (μm) of the first portion 5011 of the contour line 501 of the metal support 180 and the roughness of the other The surface roughness A12 (μm) of the first portion 5021 of the outline 502 is assumed to be equivalent. Hereinafter, the surface roughnesses A11 and A12 of the first portions 5011 and 5021 of the contour lines 501 and 502 of the metal support 180 are collectively referred to as "A1" (μm).

Similarly, the surface roughness of the surface of the metal support 180 (second metal member 182) defining the lower portion 52 of the through-hole 50 was uniform. That is, in the cross section along the Z-axis direction of the single cell 110 (for example, the cross section shown in FIG. 6), the surface roughness A21 (μm) of the second portion 5012 of the contour line 501 of the metal support 180 and the surface roughness A21 (μm) of the other The surface roughness A22 (μm) of the second portion 5022 of the outline 502 is assumed to be equivalent. Hereinafter, the surface roughnesses A21 and A22 of the second portions 5012 and 5022 of the contour lines 501 and 502 of the metal support 180 are collectively referred to as "A2" (μm).

Each sample differs from each other in properties. Specifically, each sample has a surface roughness A1 (μm) of the first portions 5011 and 5021 of the contours 501 and 502 of the metal support 180 and a surface roughness A1 (μm) of the second portions 5012 and 5022 of the contours 501 and 502. The size relationship between roughness and A2 (μm) (“A1 and A2 size relationship” column in FIG. 8) and whether or not A1/A2≧1.2 is satisfied (“A1/A2≧1 in FIG. 1.2” column) and the presence or absence of the space SP (the space SP formed in the through-hole 50 on the opposite side of the electrolyte layer 112 in the Z-axis direction inside the hole 118 of the fuel electrode 116) (“ column) are different from each other.

(Evaluation of bonding strength between fuel electrode 116 and metal support 180)
For each sample (single cell 110), an adhesive tape was attached to the surface of the fuel electrode 116, and the presence or absence of separation between the fuel electrode 116 and the metal support 180 when the adhesive tape was peeled off was checked. A sample in which the amount (area) of the fuel electrode 116 adhering to the adhesive tape after peeling off the adhesive tape was equal to or less than a predetermined determination threshold value (hereinafter referred to as “first determination threshold value”) was evaluated as “particularly good (◎ )” was evaluated. The amount of the fuel electrode 116 adhering to the adhesive tape is greater than a first determination threshold and is equal to or less than a predetermined determination threshold (hereinafter referred to as a "second determination threshold") that is greater than the first determination threshold. The sample was evaluated as "good (○)". A sample in which the amount of the fuel electrode 116 adhering to the adhesive tape was larger than the second judgment threshold was evaluated as "failed (x)". As the first determination threshold value, 10% of the area of the portion of the surface of the fuel electrode 116 to which the adhesive tape is attached is used, and as the second determination threshold value, A value of 30% of the taped area was used. The evaluation results are as shown in the column "bonding strength between fuel electrode 116 and metal support 180" in FIG.

As shown in FIG. 8, samples SP1 and SP4 were evaluated as "particularly good" because the amount of fuel electrode 116 adhering to the adhesive tape was equal to or less than the first determination threshold. In samples SP2 and SP5, the amount of fuel electrode 116 adhering to the adhesive tape was greater than the first determination threshold and less than or equal to the second determination threshold, so they were evaluated as "good." On the other hand, in samples SP3 and SP6, the amount of the fuel electrode 116 adhering to the adhesive tape was larger than the first determination threshold, so they were evaluated as "failed".

In samples SP3 and SP6, the surface roughness A1 (μm) of the first portions 5011 and 5021 of the contours 501 and 502 of the metal support 180 is the surface roughness A2 of the second portions 5012 and 5022 of the contours 501 and 502. (μm). From the above results, the surface roughness A1 (μm) of the first portions 5011 and 5021 of the contour lines 501 and 502 of the metal support 180 is the surface roughness A2 (μm) of the second portions 5012 and 5022 of the contour lines 501 and 502. μm), the amount of the fuel electrode 116 adhering to the adhesive tape is reduced, that is, it was confirmed that the single cell 110 with high bonding strength between the fuel electrode 116 and the metal support 180 can be obtained.

Further, while samples SP1 and SP4 satisfy A1/A2≧1.2, samples SP2 and SP5 do not satisfy A1/A2≧1.2. From the above results, in the configuration satisfying A1/A2≧1.2, the amount of the fuel electrode 116 adhering to the adhesive tape is particularly small, that is, the bonding strength between the fuel electrode 116 and the metal support 180 is particularly high. It was confirmed that a single cell 110 was obtained.

(Evaluation of power generation performance of single cell 110)
In this evaluation, instead of the six samples (samples SP1 to SP6) of the single cell 110 described above, six button cells manufactured according to the manufacturing method of the single cell 110 described above were used. Each sample (button cell) has the same characteristics as those of the single cell 110 described above (such as "the magnitude relationship between A1 and A2"), and is a square having sides of 25 mm when viewed from the top and bottom. The air electrode 114 having a circular shape with a diameter of 13 mm when viewed from above is formed on a laminate in which the fuel electrode 116 and the electrolyte layer 112 are laminated on the metal support 180 . In the following, for the sake of convenience, a button cell sample having the same characteristics (such as "the magnitude relationship between A1 and A2") as the sample of the single cell 110 described above will be referred to by the same reference numerals (for example, sample SP1).

For each sample (single cell 110), the oxidant gas OG was supplied to the air electrode 114 at about 700 (° C.), the fuel gas FG was supplied to the fuel electrode 116, and the current density was 0.55 A/cm ² . The output voltage of the single cell 110 was measured, and the sample whose measured value was equal to or higher than a predetermined judgment threshold (hereinafter referred to as the “third judgment threshold”) was evaluated as “passed (◯)”, and the measured value was Samples that were lower than the third determination threshold were evaluated as "failed (x)". The evaluation results are as shown in the "power generation performance" column of FIG.

As shown in FIG. 8, in samples SP1, SP2, and SP3, the measured value (the output voltage of the single cell 110) was equal to or higher than the third determination threshold, and thus was evaluated as "acceptable." On the other hand, samples SP4, SP5, and SP6 were evaluated as "failed" because the measured values were lower than the third determination threshold.

Here, the samples SP1, SP2 and SP3 have a space SP. On the other hand, in samples SP4, SP5, and SP6, there is no space SP (the entire through hole 50 is filled with the inside 118 of the fuel electrode 116). From the above results, it was confirmed that the single cell 110 with particularly high power generation performance can be obtained in the configuration with the space SP.

From the above evaluation, the surface roughness A1 (μm) of the first portions 5011 and 5021 of the contours 501 and 502 of the metal support 180 is the surface roughness A2 (μm) of the second portions 5012 and 5022 of the contours 501 and 502. It was confirmed that the structure of the single cell 110 larger than μm) has an excellent effect. Also, in a configuration in which only one of the two contour lines 501, 502 of the metal support 180 satisfies such surface roughness conditions, the effect may be somewhat less, but the same effect may be obtained. (Particularly, the effect on the "joint strength between the fuel electrode 116 and the metal support 180") can be obtained.

B. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configurations of the fuel cell stack 100 and the unit cells 110 in the above embodiment are merely examples, and various modifications are possible. For example, in the above-described embodiment, each through-hole 50 formed in the metal support 180 is composed of an upper portion 51 and a lower portion 52 , but the configuration of the through-hole 50 is different from the Z direction of the metal support 180 . As long as it penetrates from one axial surface to the other axial surface, it is not necessarily limited to this. For example, the through hole 50 formed in the metal support 180 may include a portion extending in a direction orthogonal to the Z-axis direction.

In the above embodiment (or modified example, the same applies hereinafter), each through-hole 50 of the metal support 180 in the XY cross section of the unit cell 110 is circular, but may be other than circular (for example, rectangular). . In the above embodiment, the diameter of each through-hole 50 is substantially constant from the position of the opening 53 on the upper surface S11 of the metal support 180 to the position of the opening 54 on the lower surface S22. good too. Further, although the configurations of the plurality of through holes 50 are the same in the above-described embodiment, the configuration of one of the through holes may be different from the configuration of the other through holes. For example, the diameters of the plurality of through holes 50 are substantially the same, but may be different.

In the above embodiment, the metal support 180 is made of metal (eg, stainless steel), but the surface of the base material made of metal (eg, stainless steel) may be covered with an oxide film, coating film, or the like. .

In the above embodiment, the metal support 180 is composed of the first metal member 181 and the second metal member 182 laminated in the Z-axis direction, but the configuration of the metal support 180 is not limited to this. . For example, the metal support 180 may be composed of one plate-like member, or may be composed of three or more plate-like members stacked in the Z-axis direction. Also, the first portions 5011 and 5021 and the second portions 5012 and 5022 of the outlines 501 and 502 may be formed across a plurality of plate members. Moreover, when the metal support 180 is composed of a plurality of plate-like members laminated in the Z-axis direction, the thickness of each plate-like member may be the same or different.

In the above embodiment, the second portions 5012 and 5022 of the contour lines 501 and 502 of the metal support 180 form the ends of the contour lines 501 and 502 opposite to the fuel electrode 116. The two portions 5012 , 5022 may not be the ends of the contours 501 , 502 opposite the anode 116 . In other words, the second portions 5012 and 5022 may be portions that form between the first portions 5011 and 5021 and the end opposite to the fuel electrode 116 .

In the above embodiment, the metal support 180 satisfies the formula: A1/A2≧1.2, but as long as the formula: A1>A2 is satisfied, the formula: A1/A2≧1.2 is not satisfied. good too. Note that A1 is one of a pair of contour lines defining the through-hole 50 of the metal support 180 in at least one cross section along the Z-axis direction of the unit cell 110 (hereinafter referred to as "specific cross section"). It is the surface roughness (μm) of the first portions 5011 and 5012 of the specific contour lines 501 and 502 including the ends on the fuel electrode 116 side. A2 is the surface roughness (μm) of the second portion 5012 of the specific contour lines 501 and 502 that is continuous with the first portion 5011 on the side opposite to the fuel electrode 116 .

In the above embodiment, the hole interior 118 of the anode 116 is in contact with substantially the entirety of the first portions 5011, 5021 of the contours 501, 502 of the metal support 180, but the contours 501, 502 of the metal support 180 contact with at least part of the first portions 5011 and 5021 of the . Further, in the above embodiment, the hole inside 118 of the fuel electrode 116 is not in contact with the second portions 5012 and 5022 of the contour lines 501 and 502 of the metal support 180, but the contour lines 501 and 502 of the metal support 180 It may be in contact with the second portions 5012 and 5022 .

In the above embodiment, the hole interior 118 of the fuel electrode 116 is bonded to the contour lines 501 and 502 of the metal support 180 (surfaces of the metal support 180 that define the through hole 50). As long as they are in contact with the contour lines 501 and 502 of 180, they do not have to be joined.

In the above embodiment, the hole interior 118 of the anode 116 is located only in the upper portion 51 of each through-hole 50 in this embodiment. The arrangement of 118 is not limited to this. For example, it may be positioned at the lower side portion 52 or may be positioned over the entire range in the Z-axis direction.

In the above embodiment, the present invention is applied to the fuel cell stack 100 in which the metal support 180 is located on the opposite side of the fuel electrode 116 from the electrolyte layer 112 . Moreover, the present invention may be applied to a fuel cell stack in which the metal support is a member located on the side opposite to the electrolyte layer 112 with respect to the air electrode 114 . In addition, in such a configuration, the air electrode 114 is an example of a specific electrode in the claims.

In the above embodiment, it is not necessary that all the unit cells 110 included in the fuel cell stack 100 have the above-described configuration, and at least one unit cell 110 included in the fuel cell stack 100 has the above-described configuration. should be realized. For example, in the above embodiment, the metal supports 180 included in each unit cell 110 have the same configuration, but the metal supports included in any of the single cells may have different configurations. Further, in the above-described embodiment, the configuration of the fuel electrode 116 provided in each unit cell 110 is the same, but the configuration of the fuel electrode provided in any of the unit cells may be different.

In the above-described embodiment, all the through holes 50 formed in the metal support 180 (and the hole interiors 118 of the fuel electrodes 116 located in the through holes 50) have the characteristic configuration of the present invention (formula: A11 >A21, etc.), but only one of all the through-holes 50 formed in the metal support 180 (and the hole interior 118 of the fuel electrode 116 located in the through-hole 50) It may constitute a characteristic configuration of the invention.

In the above embodiment, any cross section of the unit cell 110 along the Z-axis direction has the characteristic configuration of the present invention (formula: A11>A21, etc.). At least one cross-section along may be a characteristic feature of the invention.

The materials constituting each member in the above embodiment are merely examples, and each member may be made of another material. Moreover, the manufacturing method of the single cell 110 in the above embodiment is merely an example, and various modifications are possible.

In the above embodiment, the object is a solid oxide fuel cell (SOFC) that generates power by utilizing an electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas. The disclosed technology can also be applied to an electrolytic cell stack comprising an electrolytic single cell and a plurality of electrolytic single cells, which are constituent units of a solid oxide electrolysis cell (SOEC) that produces hydrogen using an electrolysis reaction of water. equally applicable. The configuration of the electrolysis cell stack is known, for example, as described in Japanese Patent Application Laid-Open No. 2016-81813, so it will not be described in detail here. Configuration. That is, the fuel cell stack 100 in the above-described embodiment can be read as an electrolytic cell stack, the power generation unit 102 can be read as an electrolytic cell unit, and the single cell 110 can be read as an electrolytic single cell. However, during the operation of the electrolytic cell stack, a voltage is applied between the two electrodes so that the air electrode 114 is positive (anode) and the fuel electrode 116 is negative (cathode). Water vapor is supplied as a source gas. As a result, an electrolysis reaction of water occurs in each electrolysis cell unit, hydrogen gas is generated in the fuel chamber 176 , and the hydrogen is taken out of the electrolysis cell stack through the through-hole 108 . Even in the electrolytic single cell having such a configuration, by adopting a configuration similar to that of the above-described embodiment, the same effect as that of the above-described embodiment can be obtained.

In the above embodiments, a solid oxide fuel cell (SOFC) was described as an example, but the technology disclosed herein can be applied to other types of fuel cells (or electrolysis) such as molten carbonate fuel cells (MCFC). cell).

24: Nut 26: Insulating sheet 27: Gas passage member 28: Body portion 29: Branch portion 50: Through hole 51: Upper portion (of through hole) 52: Lower portion (of through hole) 53: Opening 54: Opening 100 : Fuel cell stack 102: Power generation unit 104, 106: End plate 108: Through hole 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 117: Base (of fuel electrode) 118: Hole (of fuel electrode) Inside 120: Separator 121: Hole 124: Joint 130: Air electrode side frame member 131: Hole 132: Air electrode side gas supply communication channel 133: Air electrode side gas discharge communication channel 134: Air electrode side current collector 135 : Current collector element 140 : Fuel electrode side frame member 141 : Hole 142 : Fuel electrode side gas supply communication channel 143 : Fuel electrode side gas discharge communication channel 144 : Fuel electrode side current collector 145 : Current collector element 150 : Interconnector 161: Air electrode side gas supply manifold 162: Air electrode side gas discharge manifold 166: Air chamber 171: Fuel electrode side gas supply manifold 172: Fuel electrode side gas discharge manifold 176: Fuel chamber 180: Metal support 181: First metal member 182: Second metal member 501, 502: Contour lines 5011, 5021: First portion (of contour line) 5012, 5022: Second portion (of contour line) A1, A11, A12: (Second 1 part) surface roughness A2, A21, A22: (2nd part) surface roughness FG: Fuel gas FOG: Fuel off-gas OG: Oxidant gas OOG: Oxidant off-gas S11: Upper surface S12: Lower surface S21: Upper surface S22 : Lower surface SP: Space

Claims (6)

an electrolyte layer;
a fuel electrode and an air electrode facing each other in a first direction with the electrolyte layer interposed therebetween;
A metal support located on a side opposite to the electrolyte layer with respect to a specific electrode, which is one of the fuel electrode and the air electrode, and the metal support at a position overlapping the specific electrode when viewed in the first direction. and a metal support having a plurality of through-holes penetrating in one direction,
The specific electrode has an electrode hole interior positioned within a specific through hole that is at least one of the plurality of through holes,
In a specific cross section that is at least one cross section along the first direction of the electrochemical reaction unit cell,
Let A1 (μm) be the surface roughness of a first portion including an end on the side of the specific electrode of a specific contour line that is one of a pair of contour lines defining the specific through-hole of the metal support, and When the surface roughness of the second portion of the specific contour line, which is continuous with the first portion on the side opposite to the specific electrode, is A2 (μm),
Formula: satisfies A1>A2, and
the inside of the electrode hole is in contact with at least part of the first portion of the metal support;
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to claim 1,
Formula: satisfies A1/A2≧1.2,
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to claim 1 or claim 2,
The metal support is
a first metal member having the first portion of the specific contour;
a second metal member having the second portion of the specific outline;
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to any one of claims 1 to 3,
In the specific cross section,
The specific through-hole has a space inside the electrode hole on a side opposite to the electrolyte layer in the first direction,
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to claim 4,
In the specific cross section,
The length in the first direction of the joint portion where the first portion of the specific contour line of the metal support and the specific electrode are joined is the length of the first part of the specific contour line of the metal support. greater than the length in the first direction of the joint where the two parts and the specific electrode are joined;
An electrochemical reaction single cell characterized by: A method for manufacturing an electrochemical reaction single cell according to claim 4 or 5,
a first step of preparing the metal support and a paste-like material for forming the specific electrode;
A second step of disposing the paste-like material on the metal support, wherein the paste material is poured from the first portion side to the second portion side into the specific through-hole formed in the metal support. and,
By curing at least the paste-like material, the specific electrode provided with the inside of the electrode hole and the metal support, and the specific through hole is the electrolyte in the first direction inside the electrode hole a third step of obtaining a member having a space on the opposite side of the layer;
A method for manufacturing an electrochemical reaction single cell, characterized by:

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