JP2022146310A - electrochemical reaction single cell - Google Patents

Abstract

To effectively suppressing peeling of a specific electrode from a metal support body.SOLUTION: An electrochemical reaction single cell comprises: an electrolyte layer; a fuel electrode and an air electrode which face each other to a first direction while nipping the electrolyte layer; and a metal support body that is arranged at the side opposite to the electrolyte layer against a base part as one part which is near from the electrolyte layer in a specific electrode as one of the fuel electrode and the air electrode. In the metal support body, a plurality of penetration holes penetrated to a second surface opposite to a first surface from the first surface on the base part of the specific electrode is formed. At least one part of the plurality of penetration holes of the metal support body is a first part containing an opening in the first surface, and includes the first part extending to a direction where an angle θ1 formed by the first direction is larger than 0 degrees and smaller than 90 degrees. The specific electrode is continued to the base part, and includes a filling part filled into at least one part of the first part of each penetration hole of the metal support body.SELECTED DRAWING: Figure 6

Description

The technology disclosed by this specification relates to 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 the single cell, a metal-supported single cell is known. 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. Conventionally, a metal support has a plurality of through-holes extending parallel to the first direction (the arrangement direction of each component of the unit cell), and each through-hole is partially filled with a specific electrode. is known (see, for example, Patent Document 1).

JP-A-2005-93262

A metal-supported single cell has a problem that the specific electrode tends to separate from the metal support because the surface of the metal support is relatively smooth. In the single cell having the above-described conventional configuration, the plurality of through holes formed in the metal support are partially filled with the specific electrode, but the plurality of through holes are arranged in the first direction (each component of the single cell). arrangement direction), the portion of the specific electrode filled in the through-hole does not effectively function as an anchor, and the occurrence of detachment cannot be effectively suppressed.

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 is an electrochemical reaction single cell comprising an electrolyte layer, and a fuel electrode and an air electrode facing each other in a first direction with the electrolyte layer interposed therebetween. a metal support arranged on the side opposite to the electrolyte layer with respect to a base portion, which is a part of a specific electrode, which is one of the fuel electrode and the air electrode, on the side closer to the electrolyte layer; The metal support has a plurality of through-holes penetrating from a first surface on the base side of the specific electrode to a second surface opposite to the first surface. At least part of the plurality of through-holes in the body is a first portion including openings on the first surface, and forms an angle θ1 with the first direction greater than 0 degrees and greater than 90 degrees. Having a first portion extending in a small direction, the specific electrode has a filling portion that is continuous with the base portion and that fills at least a portion of the first portion of the through hole of the metal support. .

In this electrochemical reaction single cell, when a force (a force substantially parallel to the first direction) separating the specific electrode and the metal support due to, for example, the difference in the thermal expansion coefficient of each member acts, the specific electrode The portion filled in the first portion of the through-hole in the filled portion of the through-hole, that is, the portion extending in the direction where the angle θ1 formed with the first direction is larger than 0 degrees and smaller than 90 degrees is the first portion of the through-hole It engages the inner wall surface of part 1 and effectively functions as an anchor. Therefore, according to the present electrochemical reaction single cell, it is possible to effectively suppress peeling of the specific electrode from the metal support.

(2) In the above electrochemical reaction single cell, at least some of the plurality of through-holes of the metal support are, in addition to the first portion, second portions communicating with the first portions. a second portion forming an angle θ2 with the first direction greater than 0 degrees and less than 90 degrees and extending in a direction different from the extending direction of the first portions; The filling portion of the specific electrode includes a portion of the first portion of the through hole of the metal support from the opening on the first surface to the second portion, and the second portion of the through hole. At least a portion continuous with the first portion may be filled. In this electrochemical reaction single cell, when a force acts to separate the specific electrode and the metal support, the portion filled in the first portion of the through hole in the filling portion of the specific electrode effectively functions as an anchor. In addition to the above, the portion filled in the second portion of the through hole in the filling portion of the specific electrode, that is, extends in a direction at which the angle θ2 formed with the first direction is greater than 0 degrees and less than 90 degrees. The portion engages the inner wall surface of the second portion of the throughbore to effectively function as an anchor. In addition, in the through-hole, the extending direction of the second portion is different from the extending direction of the first portion. It has a bent shape at the location of the first portion and the second portion, and functions as a strong anchor. Therefore, according to the present electrochemical reaction single cell, it is possible to extremely effectively suppress the separation of the specific electrode from the metal support.

(3) In the above electrochemical reaction single cell, the metal support has a configuration in which a plurality of plate-like members are stacked in the first direction, and the first The portion and the second portion may be configured to be formed on the plate-like members different from each other. According to this electrochemical reaction single cell, it is possible to easily form a through-hole having a first portion and a second portion extending in different directions in a metal support.

(4) In the above electrochemical reaction single cell, at least one of the filling portions of the specific electrode extends from the position of the opening of the through-hole of the metal support on the first surface to the second surface. It is good also as a structure extended to the position near the said 1st surface from the opening in. In this electrochemical reaction single cell, a space without a filling portion is secured in a part of the through-hole of the metal support near the opening on the second surface. Therefore, according to the present electrochemical reaction single cell, it is possible to promote the inflow of the reaction gas into the through-hole while suppressing the separation of the specific electrode from the metal support, and the gas diffusibility on the side of the specific electrode can be improved. Decrease can be suppressed.

(5) In the above electrochemical reaction single cell, the plurality of through holes of the metal support may include a plurality of through holes in which the extending directions of the first portions are different from each other. According to the present electrochemical reaction single cell, the plurality of filling portions of the specific electrode have different extending directions, and function as a strong anchor as a whole. Therefore, according to the present electrochemical reaction single cell, it is possible to extremely effectively suppress the separation of the specific electrode from the metal support.

The technology disclosed in this specification can be implemented in various forms. For example, an electrochemical reaction single cell (fuel cell single cell or electrolytic single cell), a plurality of electrochemical reaction single cells It can be realized in the form of an electrochemical reaction cell stack (fuel cell stack or electrolysis cell stack), manufacturing methods thereof, and the like.

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. Explanatory diagram showing the detailed configuration of the single cell 110 in the present embodiment

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 oxidant gas OG (for example, oxidant gas) from the outside of the fuel cell stack 100 to 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 . 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 generating unit 102 and electrically connected to the power generating unit 102 . The other end plate 106 is arranged below the lowermost power generation unit 102 and is electrically connected with 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 single cell 110 is an example of an electrochemical reaction single cell in the claims.

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). As will be described later, the metal support 180 is formed with a plurality of through holes 50 for passing the fuel gas FG (see FIG. 6).

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). The fuel electrode 116 is an example of 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 consists 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 air is supplied to the air electrode side gas supply manifold 161 via the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and the air electrode side gas supply communication channel of each power generation unit 102 from the air electrode side gas supply manifold 161. 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 diagram showing the detailed configuration of the single cell 110 in this embodiment. FIG. 6 shows an enlarged view of the YZ cross-sectional configuration of the single cell 110 at the X1 portion of FIG.

As shown in FIG. 6 , in the single cell 110 of this embodiment, a plurality of through holes 50 are formed in the metal support 180 . In the metal support 180, each through-hole 50 extends from the upper surface S1 on the side of the fuel electrode 116 (more specifically, the base portion 117, which is a portion of the fuel electrode 116 on the side closer to the electrolyte layer 112), to the side opposite to the upper surface S1. It penetrates to the lower surface S2. The upper surface S1 of the metal support 180 is an example of a first surface in the claims, and the lower surface S2 of the metal support 180 is an example of a second surface in the claims.

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

Each through-hole 50 formed in the metal support 180 has a first portion 51 including an opening 53 in the upper surface S1 of the metal support 180. As shown in FIG. A first portion 51 of each through-hole 50 is formed in a first plate member 181 that constitutes the metal support 180 . The first portion 51 of each through-hole 50 extends substantially linearly in a direction that forms an angle θ1 with the Z-axis direction that is larger than 0 degrees and smaller than 90 degrees. That is, the extending direction of the first portion 51 of each through-hole 50 is neither parallel to the Z-axis direction nor a direction orthogonal to the Z-axis direction, but is a so-called oblique direction. The extending directions of the first portions 51 of the through holes 50 are not aligned in the same direction. That is, the plurality of through holes 50 formed in the metal support 180 include the plurality of through holes 50 in which the extending directions of the first portions 51 are different from each other. An angle θ1 between the extending direction of the first portion 51 of each through-hole 50 and the Z-axis direction is preferably larger than 10 degrees and smaller than 50 degrees, and more preferably larger than 20 degrees and smaller than 40 degrees.

Each through-hole 50 formed in the metal support 180 has a second portion 52 communicating with the first portion 51 in addition to the first portion 51 . The second portion 52 is a portion including the opening 54 in the lower surface S2 of the metal support 180. As shown in FIG. That is, in this embodiment, each through hole 50 is composed of a first portion 51 and a second portion 52 . In each through-hole 50, the second portion 52 forms an angle θ2 with the Z-axis direction that is greater than 0 degrees and less than 90 degrees, and is substantially linear in a direction different from the extending direction of the first portions 51. is extended to That is, the extension direction of the second portion 52 of each through-hole 50 is neither parallel to the Z-axis direction nor a direction orthogonal to the Z-axis direction, but a so-called oblique direction. The connecting portion between the first portion 51 and the second portion 52 is bent. The extending directions of the second portions 52 of the through holes 50 are not aligned in the same direction. That is, the plurality of through holes 50 formed in the metal support 180 include the plurality of through holes 50 in which the extension directions of the second portions 52 are different from each other. The angle θ2 between the extending direction of the second portion 52 of each through-hole 50 and the Z-axis direction is preferably greater than 10 degrees and less than 50 degrees, and more preferably greater than 20 degrees and less than 40 degrees.

In this embodiment, the diameter of each through-hole 50 is substantially constant from the position of the opening 53 on the upper surface S1 of the metal support 180 to the position of the opening 54 on the lower surface S2. Also, the diameters of the plurality of through holes 50 are substantially the same.

The fuel electrode 116 has a plurality of filling portions 118 in addition to the above-described base portion 117 (a portion of the side close to the electrolyte layer 112 and a plate-shaped member substantially orthogonal to the Z-axis direction). Each filling portion 118 continues to the base portion 117 and fills the through hole 50 formed in the metal support 180 . Each filling portion 118 extends from the position of the opening 53 in the upper surface S1 of the through-hole 50 of the metal support 180 to a position closer to the upper surface S1 than the opening 54 in the lower surface S2. That is, each filling portion 118 is continuous with the portion of the first portion 51 of the through-hole 50 from the opening 53 in the upper surface S1 to the second portion 52 and the first portion 51 in the second portion 52. It is filled in the part that does (upper part). As a result, a space SP in which the filling portion 118 does not exist is secured in a lowermost portion of the through-hole 50 (a lower portion of the second portion 52). The fuel gas FG supplied to the fuel chamber 176 advances from the space SP through the gaps of the filling portions 118 of the fuel electrode 116, further advances through the gaps of the base 117 of the fuel electrode 116, and is supplied to the reaction field. be done.

The single cell 110 having such a configuration can be manufactured, for example, by the following manufacturing method. First, the first plate-like member 181 and the second plate-like member 182 that constitute the metal support 180 are prepared, and the first portions 51 of the through-holes 50 are formed in the first plate-like member 181 by punching. is formed, and the second portion 52 of each through-hole 50 is formed in the second plate member 182 . Next, the first plate-like member 181 and the second plate-like member 182 are aligned so that each first portion 51 communicates with each second portion 52, and are joined by welding, for example. to fabricate the metal support 180 . In this embodiment, since the thickness of the first plate-like member 181 and the thickness of the second plate-like member 182 are substantially the same, the positions and the number of the first portions 51 and the second portions 52 are changed. By adjusting, a plurality of plate-shaped members of the same size are subjected to the same drilling process, some of the plurality of plate-shaped members are used as the first plate-shaped member 181, and other of the plurality of plate-shaped members are used. Since a part of it can be used as the second plate member 182, efficiency of mass production can be realized.

Next, pastes for forming filling portion 118 and base portion 117 of fuel electrode 116 are prepared. Then, each through-hole 50 formed in the metal support 180 is filled with a paste for forming the filling portion 118 . At this time, the lowermost part of each through-hole 50 (the lower part of the second part 52) of the metal support 180 is filled with resin, for example, so that the paste for forming the filling part 118 is formed. Do not fill the part. After that, a film is formed by applying a paste for forming the base portion 117 to the upper surface S1 of the metal support 180 . The paste for forming filling portion 118 and the paste for forming base portion 117 may have the same composition or may have different compositions.

Next, a paste for forming the electrolyte layer 112 is prepared and applied on the coating film of the paste for forming the base 117 of the fuel electrode 116 to form a film. By firing the laminate thus produced at a predetermined temperature, the electrolyte layer 112 and the fuel electrode 116 are formed, and a laminate of the metal support 180, the electrolyte layer 112, and the fuel electrode 116 is obtained. Next, a paste for forming the air electrode 114 is prepared and applied on the electrolyte layer 112 to form a film. By firing the laminated body thus produced at a predetermined temperature, the air electrode 114 is formed and the single cell 110 having the above-described structure is obtained.

A-4. 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 disposed on the side opposite to the electrolyte layer 112 with respect to the base portion 117 , which is the portion of the anode 116 closer to the electrolyte layer 112 . A plurality of through holes 50 are formed in the metal support 180 so as to extend from the upper surface S1 of the fuel electrode 116 on the side of the base 117 to the lower surface S2 opposite to the upper surface S1. Each through-hole 50 formed in the metal support 180 has a first portion 51 including an opening 53 in the top surface S1. The first portion 51 extends in a direction in which the angle θ1 formed with the Z-axis direction is greater than 0 degrees and less than 90 degrees. The fuel electrode 116 has a filling portion 118 that continues from the base portion 117 and fills at least a portion of the first portion 51 of each through hole 50 of the metal support 180 .

Since the unit cell 110 of this embodiment has the above structure, the force (the force substantially parallel to the Z-axis direction) separating the fuel electrode 116 and the metal support 180 due to, for example, the difference in the coefficient of thermal expansion of each member. When the fuel electrode 116 is actuated, the portion filled in the first portion 51 of the through hole 50 in each filling portion 118 of the fuel electrode 116, that is, in the direction where the angle θ1 with the Z-axis direction is greater than 0 degrees and less than 90 degrees. The extending portion engages the inner wall surface of the first portion 51 of the through hole 50 and effectively functions as an anchor. Therefore, according to the single cell 110 of the present embodiment, separation of the fuel electrode 116 from the metal support 180 can be effectively suppressed.

Further, in the single cell 110 of the present embodiment, each through-hole 50 formed in the metal support 180 has a second portion 52 communicating with the first portion 51 in addition to the first portion 51 . The second portion 52 forms an angle θ2 with the Z-axis direction that is greater than 0 degrees and less than 90 degrees, and extends in a direction different from the extending direction of the first portions 51 . In addition, each filling portion 118 of the fuel electrode 116 includes a portion of the first portion 51 of the through-hole 50 of the metal support 180 from the opening 53 in the upper surface S1 to the second portion 52, and the second portion. At least a portion of 52 that is continuous with the first portion 51 is filled. Since the single cell 110 of the present embodiment has the above structure, when a force separating the fuel electrode 116 and the metal support 180 acts, the first portion 51 of the through-hole 50 in each filling portion 118 of the fuel electrode 116 In addition to effectively functioning as an anchor, the portion filled in the second portion 52 of the through-hole 50 in each filling portion 118 of the fuel electrode 116, that is, the Z-axis direction. The portion extending in the direction where the angle θ2 is larger than 0 degrees and smaller than 90 degrees engages the inner wall surface of the second portion 52 of the through-hole 50 and effectively functions as an anchor. In addition, in each through-hole 50, since the extending direction of the second portion 52 is different from the extending direction of the first portion 51, the first portion 51 and the second portion 52 of each through-hole 50 are filled. The filling portion 118 of the fuel electrode 116 has a bent shape at the location between the first portion 51 and the second portion 52 and functions as a strong anchor. Therefore, according to the single cell 110 of the present embodiment, separation of the fuel electrode 116 from the metal support 180 can be suppressed extremely effectively.

Further, in the single cell 110 of the present embodiment, the metal support 180 has a configuration in which a plurality of plate-like members 181 and 182 are stacked in the Z-axis direction, and the first through-holes 50 of the metal support 180 The portion 51 and the second portion 52 are formed on plate-like members 181 and 182 different from each other. Therefore, according to the single cell 110 of the present embodiment, the through-hole 50 having the first portion 51 and the second portion 52 extending in different directions can be easily formed in the metal support 180 .

Further, in the single cell 110 of the present embodiment, each filling portion 118 of the fuel electrode 116 is closer to the upper surface S1 than the opening 54 of the lower surface S2 of the through-hole 50 of the metal support 180 from the position of the opening 53 on the upper surface S1. Extends to position. That is, in the single cell 110 of this embodiment, a space SP in which the filling portion 118 does not exist is secured in a part of the lowermost portion of each through hole 50 of the metal support 180 . Therefore, according to the single cell 110 of the present embodiment, it is possible to suppress the separation of the fuel electrode 116 from the metal support 180 and promote the flow of the fuel gas FG into each through-hole 50. A decrease in gas diffusivity on the 116 side can be suppressed.

Further, in the single cell 110 of the present embodiment, the plurality of through holes 50 formed in the metal support 180 include the plurality of through holes 50 in which the extending directions of the first portions 51 are different from each other. Therefore, according to the unit cell 110 of the present embodiment, the plurality of filling portions 118 of the fuel electrode 116 have shapes with different extending directions, and function as a strong anchor as a whole. Therefore, according to the single cell 110 of the present embodiment, separation of the fuel electrode 116 from the metal support 180 can be suppressed extremely effectively.

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 embodiment, each through-hole 50 formed in the metal support 180 is composed of the first portion 51 and the second portion 52, but the configuration of the through-hole 50 is not necessarily limited to this. can't For example, the through hole 50 formed in the metal support 180 may be composed of only the first portion 51, or the second portion 52 may be composed of the first portion 51 and the second portion 52 in addition to the first portion 51 and the second portion 52. It may have a third portion communicating with the second portion 52 and extending in a direction different from that of the second portion 52, and similarly may have a fourth and subsequent portions. In the above-described embodiment, the second portion 52 of the through-hole 50 extends in the direction where the angle θ2 formed with the Z-axis direction is greater than 0 degrees and less than 90 degrees. The direction may be parallel to the Z-axis direction.

In the above embodiment, the extending directions of the first portions 51 of the through holes 50 formed in the metal support 180 are not aligned in the same direction, but the extending directions of the first portions 51 of the through holes 50 may be aligned in the same direction. Similarly, in the above-described embodiment, the extending directions of the second portions 52 of the through-holes 50 formed in the metal support 180 are not aligned in the same direction, but the second portions 52 of the through-holes 50 may be aligned in the same direction.

In the above-described embodiment, at the connection point between the first portion 51 and the second portion 52 of each through-hole 50 formed in the metal support 180, the first portion 51 and the second portion 51 are connected in the direction orthogonal to the Z-axis direction. Although the position of the second portion 52 is the same, the positions may be shifted as long as the first portion 51 and the second portion 52 are in communication. This point is the same when each through-hole 50 has a third and subsequent portions.

In the above-described embodiment, each filling portion 118 of the fuel electrode 116 includes a portion of the first portion 51 of the through-hole 50 from the opening 53 in the upper surface S1 to the second portion 52, and Although a portion (an upper portion) continuous with the first portion 51 is filled, the configuration of the filling portion 118 is not necessarily limited to this. For example, the filling portion 118 of the fuel electrode 116 fills the first portion 51 of the through-hole 50 from the opening 53 in the upper surface S1 to the second portion 52, but the second portion 52 may not be filled. It should be noted that filling portion 118 of fuel electrode 116 filled into first portion 51 of through-hole 50 from opening 53 in upper surface S1 to second portion 52 does not necessarily mean the first portion. It does not mean only the form in which the filling part 118 is filled in the part 51 without gaps, but the filling part 118 is continuously positioned from the opening 53 in the upper surface S1 until it reaches the second part 52. As far as possible, it includes a form in which there is a portion where the filling portion 118 does not exist in that portion of the first portion 51 . In addition, the filling portion 118 of the fuel electrode 116 is filled only in the upper portion of the first portion 51 of the through-hole 50, not the portion from the opening 53 in the upper surface S1 to the second portion 52. good too. In addition, the filled portion 118 of the fuel electrode 116 is the portion of the first portion 51 of the through hole 50 from the opening 53 in the upper surface S1 to the second portion 52, and the lower surface S2 of the second portion 52. A portion from the opening 54 to the first portion 51 may be filled. That is, the filling portion 118 of the fuel electrode 116 may extend from the position of the opening 53 on the upper surface S1 of the through-hole 50 to the position of the opening 54 on the lower surface S2. Thus, the configuration of each filling portion 118 of the fuel electrode 116 can be arbitrarily changed as long as at least a portion of the first portion 51 of the through hole 50 is filled. This point is the same when each through-hole 50 is composed of only the first portion 51 or has the third and subsequent portions.

In the above embodiment, the metal support 180 is composed of the first plate-like member 181 and the second plate-like member 182 laminated in the Z-axis direction, but the structure of the metal support 180 is limited to this. can't 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. 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. Moreover, a coat layer may be formed on the surface of the metal support 180 .

The configuration of the through-holes 50 of the metal support 180 and the filling portions 118 of the fuel electrode 116 in the above-described embodiment is as follows: It does not have to be implemented in 118, and may be implemented in at least a portion of the plurality of through holes 50 formed in the metal support 180 and the filling portion 118 filled in the portion.

In the above embodiment, the metal support 180 is disposed on the opposite side of the anode 116 (the base portion 117, which is a portion of the anode 116 on the side closer to the electrolyte layer 112) than the electrolyte layer 112. Alternatively, the metal support 180 may be arranged on the side opposite to the electrolyte layer 112 with respect to the cathode 114 (the base portion, which is the portion of the cathode 114 on the side closer to the electrolyte layer 112 ). Even in such a case, the through hole 50 of the metal support 180 and the filling portion of the air electrode 114 filled in the through hole 50 are configured in the same manner as described above, so that the separation of the air electrode 114 from the metal support 180 can be prevented. can be effectively suppressed. In addition, in such a configuration, the air electrode 114 is an example of a specific electrode in the claims.

In the above embodiment, an element (for example, Sr) diffused from the air electrode 114 reacts with an element (for example, Zr) contained in the electrolyte layer 112 between the air electrode 114 and the electrolyte layer 112 of the single cell 110. An anti-reaction layer may be placed to suppress the formation of highly resistive materials (eg, SrZrO ₃ ). The reaction prevention layer is made of, for example, a ceria-based ion conductor material.

Further, in the above-described embodiment, it is not necessary that all the single cells 110 included in the fuel cell stack 100 have the above configuration, and at least one single cell 110 included in the fuel cell stack 100 has the above configuration. It suffices if a configuration that

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).

22: Bolt 24: Nut 26: Insulating sheet 27: Gas passage member 28: Body portion 29: Branch portion 50: Through hole 51: First portion 52: Second portion 53: Opening 54: Opening 100: Fuel cell stack 102: Power generation unit 104: End plate 106: End plate 108: Through hole 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 117: Base 118: Filling part 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 plate member 182: second plate FG: Fuel gas FOG: Fuel off-gas OG: Oxidant gas OOG: Oxidant off-gas S1: Upper surface S2: Lower surface SP: Space

Claims (5)

An electrochemical reaction single cell comprising an electrolyte layer, and a fuel electrode and an air electrode facing each other in a first direction with the electrolyte layer interposed therebetween, further comprising:
a metal support disposed on the side opposite to the electrolyte layer with respect to a base portion, which is a portion of the specific electrode, which is one of the fuel electrode and the air electrode, on the side closer to the electrolyte layer;
The metal support has a plurality of through-holes penetrating from a first surface on the base side of the specific electrode to a second surface opposite to the first surface,
At least some of the plurality of through-holes of the metal support are a first portion including openings on the first surface, and form an angle θ1 with the first direction greater than 0 degrees. having a first portion extending in a direction less than 90 degrees;
The specific electrode has a filling portion that is continuous with the base and that fills at least a portion of the first portion of the through hole of the metal support,
An electrochemical reaction single cell characterized by: In the electrochemical reaction single cell according to claim 1,
At least some of the plurality of through-holes of the metal support are, in addition to the first portion, second portions communicating with the first portions, and are oriented in the first direction. having an angle θ2 greater than 0 degree and less than 90 degrees and extending in a direction different from the direction of extension of the first portion;
The filling portion of the specific electrode includes a portion of the first portion of the through-hole of the metal support from the opening on the first surface to the second portion, and the second portion. at least a portion continuous with the first portion in
An electrochemical reaction single cell characterized by: In the electrochemical reaction single cell according to claim 2,
The metal support has a configuration in which a plurality of plate-like members are laminated in the first direction,
wherein the first portion and the second portion of the through-hole of the metal support are formed on the plate-like members different from each other;
An electrochemical reaction single cell characterized by: In the electrochemical reaction single cell according to any one of claims 1 to 3,
At least one of the filling portions of the specific electrode is positioned closer to the first surface than the opening on the second surface from the position of the opening on the first surface of the through hole of the metal support. extends up to
An electrochemical reaction single cell characterized by: In the electrochemical reaction single cell according to any one of claims 1 to 4,
The plurality of through-holes of the metal support include a plurality of through-holes in which the extending directions of the first portion are different from each other,
An electrochemical reaction single cell characterized by:

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