JP2022146309A - Electrochemical reaction single cell and electrochemical reaction cell stack - Google Patents

Abstract

To provide an electrochemical reaction single cell capable of 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 positioned at the side opposite to the electrolyte layer against one (a specific electrode) of the fuel electrode and the air electrode. The metal support body includes a plurality of penetration holes penetrated to a first direction. The specific electrode comprises an electrode hole inner part in one (the specific electrode) of the plurality of penetration holes. In a specific cross section along a first direction of the electrochemical reaction single cell, at least one of two border lines defining a specific penetration hole of the metal support body, includes a step part having: a first extension part extending along the first direction; a second extension part extending along a second direction from the first extension part; and a third extension part extending along the first direction from the second extension part. The electrode hole inner part includes a specific part positioned at the side opposite to the electrolyte layer of the first direction of the second extension part.SELECTED DRAWING: Figure 6

Description

The technology disclosed by this specification relates to an electrochemical reaction single cell and an electrochemical reaction cell stack.

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 plurality of through-holes penetrating in the first direction are formed in the metal support at positions overlapping the specific electrodes when viewed in the first direction, and the specific electrodes are entirely aligned with the through-holes of the metal support. A configuration located on the electrolyte layer side in the first direction is known (see, for example, Patent Document 1).

Japanese Patent No. 5423093

In the conventional metal-supported single cell, as described above, the entire specific electrode is positioned on the side of the electrolyte layer in the first direction with respect to the through-hole of the metal support. It does not have a portion located within the through hole of the metal support. In this single cell, the contact area between the specific electrode and the metal support is reduced due to the existence of the plurality of through-holes formed in the metal support, so that the bonding strength between the specific electrode and the metal support is reduced. This may lead to detachment of the specific electrode from the metal support.

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 the specific cross section that is at least one cross section along the first direction of the reaction unit cell, at least one of the two contour lines defining the specific through-hole of the metal support is aligned in the first direction. a first extending portion extending from an end portion on the electrolyte layer side, the first extending portion including a portion extending along the first direction; a second extending portion extending from an end opposite to the electrolyte layer in a first direction, the first extending portion being selected in a second direction intersecting the first direction; a second extending portion including a portion extending along a centrifugal direction that is a direction away from the center of the electrolyte layer side portion of the specific through-hole defined by the centrifugal direction of the second extending portion a third extension extending from an end of the third extension including a portion extending along a side opposite to the electrolyte layer in the first direction; One step portion is provided, and the inside of the electrode hole has a specific portion located on the side opposite to the electrolyte layer in the first direction with respect to the second extending portion.

In the present electrochemical reaction single cell, as described above, the specific electrode (one of the fuel electrode and the air electrode) is provided with the inside of the electrode hole located in the specific through hole (at least one of the plurality of through holes). . In a particular cross-section, the contour line, which is one of the two contour lines that define the specific through-hole of the metal support, is the first has a stepped portion of The inside of the electrode hole of the specific electrode extends in the centrifugal direction (a direction away from the center of the electrolyte layer side portion of the specific through-hole defined by the first extending portion in the second direction that intersects with the first direction). It has a specific portion located on the opposite side of the electrolyte layer in the first direction with respect to the extending second extension. In this electrochemical reaction single cell, when a force (a force substantially parallel to the first direction) separating the first stepped portion of the metal support and the specific portion of the specific electrode acts, the specific portion of the specific electrode is It engages the first stepped portion of the metal support and effectively functions as an anchor. Therefore, in the present electrochemical reaction single cell, the relative first direction between the specific electrode and the metal support (more specifically, the direction in which the specific electrode and the metal support separate from each other in the first direction) It is possible to suppress positional displacement, and in turn, to suppress peeling of the specific electrode from the metal support.

(2) In the above electrochemical reaction single cell, the specific portion may be joined to the second extending portion in the specific cross section. As the length of the inside of the electrode hole in the first direction increases, the flowability of the reaction gas through the through-hole of the metal support deteriorates, and the performance of the electrochemical reaction single cell deteriorates. In the present electrochemical reaction unit cell, as described above, in the specific cross section, the specific portion of the specific electrode is defined by the first extending portion in the centrifugal direction (the second direction intersecting the first direction). The specific part of the specific electrode is joined to the part that extends along the first direction. The contact area between the specific electrode and the metal support can be increased without increasing the length of the inside of the electrode hole in the first direction, as compared with the structure having the structure described above. Therefore, according to the present electrochemical reaction single cell, the performance of the electrochemical reaction single cell is suppressed from deteriorating due to the flowability of the reaction gas through the through-holes of the metal support, and the specific electrode and the metal support are connected. can improve the bonding strength.

(3) In the above electrochemical reaction single cell, in the specific cross section, the specific through-hole may have a space inside the electrode hole on the side opposite to the electrolyte layer in the first direction. In the present electrochemical reaction single cell, as described above, the metal support has the first step portion and the specific electrode has the specific portion, thereby suppressing separation of the specific electrode from the metal support. can do. According to the present electrochemical reaction single cell, although such an effect can be obtained, as described above, the specific through-hole has a space on the side opposite to the electrolyte layer in the first direction inside the electrode hole. Thus, compared to a configuration in which the specific through-hole does not have the space (for example, a configuration in which the entire specific through-hole is filled with the specific electrode), the flowability of the reaction gas passing through the specific through-hole is improved. and, in turn, the performance of the electrochemical reaction single cell can be improved.

(4) In the above electrochemical reaction unit cell, the metal support is a plate-shaped first metal member, and has a first surface including the second extending portion, and A plate-shaped first metal member having a through hole penetrating in a first direction, the through hole constituting the electrolyte layer side portion of the specific through hole defined by the first extending portion. and a plate-shaped second metal member having a second surface joined to the first surface, the through hole penetrating from the second surface in the first direction, A second metal member having a through hole forming a portion of the specific through hole defined by the second extending portion and the third extending portion on the side opposite to the electrolyte layer. good. In the present electrochemical reaction unit cell, the first stepped portion is connected to the through hole of the plate-shaped first metal member when the first metal member and the second metal member are joined together. , can be easily realized (manufactured) by adjusting the relative position of the plate-shaped second metal member with respect to the through hole. Further, the specific portion of the specific electrode is a material (for example, paste, hereinafter referred to as "electrode material") forming the specific electrode, and the plate-like through hole of the plate-like first metal member. When forming a specific electrode by filling each of the through holes of the second metal member, it is easy to adjust the configuration (for example, filling amount and filling position) of the electrode material to be filled in each through hole. can be realized (manufactured) in

(5) In the electrochemical reaction single cell, in the specific cross section, the other of the two contour lines defining the specific through-hole of the metal support is an end portion on the electrolyte layer side in the first direction. a fourth extension extending from the fourth extension including a portion extending along the first direction; and the fourth extension in the first direction of the A fifth extending portion extending from an end opposite to the electrolyte layer, the electrolyte layer side of the specific through-hole defined by the fourth extending portion in the second direction A fifth extension portion including a portion extending along a centripetal direction, which is a direction toward the center of the portion, and a sixth extension portion extending from an end of the fifth extension portion in the centripetal direction. and a sixth extending portion including a portion extending along the side opposite to the electrolyte layer in the first direction, wherein the specific electrode is: It is good also as a structure joined to the said 5th extending|stretching part. In the present electrochemical reaction single cell, the portion of the specific electrode that is bonded to the fifth extending portion of the metal support is bonded to the portion of the specific through-hole extending along the first direction. In comparison, the contact area between the specific electrode and the metal support can be increased without increasing the length of the inside of the electrode hole in the first direction. Therefore, in the present electrochemical reaction single cell, it is possible to more effectively suppress the deterioration of the performance of the electrochemical reaction single cell due to the flowability of the reaction gas through the through-holes of the metal support, and the specific electrode and It is possible to improve the bonding strength with the metal support.

(6) The electrochemical reaction cell stack disclosed in the present specification includes the electrochemical reaction single cell according to any one of (1) to (5) above and a gas chamber facing the specific electrode. each having a plurality of electrochemical reaction units arranged side by side in the first direction, and in at least one of the electrochemical reaction units, the centrifugal direction (the second direction intersecting the first direction of these, the direction away from the center of the electrolyte layer side portion of the specific through hole defined by the first extending portion) is the direction opposite to the direction of gas flow in the gas chamber in the second direction. is. Therefore, in the present electrochemical reaction cell stack, the first stepped portion is arranged in the centrifugal direction in the order of the first extending portion, the second extending portion, and the third extending portion. Further, in the present electrochemical reaction cell stack, as described above, the centrifugal direction is opposite to the direction of gas flow in the fuel chamber in the second direction (direction intersecting the first direction). , the first stepped portion is arranged in the order of the third extending portion, the second extending portion, and the first extending portion in the gas flow direction in the second direction. The arrangement order of the third extending portion, the second extending portion, and the first extending portion is also the direction of the gas flow in the first direction (the direction of the electrolyte layer with respect to the metal support in the first direction). Match. Therefore, according to the present electrochemical reaction single cell, for example, the centrifugal direction is the direction of gas flow (that is, the first extending portion, the second extending portion, and the third extending portion in the direction of gas flow). , etc.), the flowability of the reaction gas passing through the specific through-holes can be improved, and the performance of the electrochemical reaction single cell can be improved.

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. The power generation unit 102 is an example of an electrochemical reaction unit in the 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 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). 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 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. The cross section of the unit cell 110 shown in FIGS. 5 and 6 is a cross section along the Z-axis direction, and is an example of a specific cross section in the scope of claims.

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 S11 contacting 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 S11. is penetrated to the lower surface S22 of the . From this, it can be said that each through-hole 50 is a hole penetrating in the Z-axis direction.

In this embodiment, 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. In this embodiment, the thickness of the first metal member 181 and the thickness of the second metal member 182 are substantially the same. The lower surface S12 of the first metal member 181 is an example of the first surface in the claims, and the upper surface S21 of the second metal member 182 is an example of the second surface in the claims. be.

Each through-hole 50 formed in the metal support 180 has a first portion 51 including an opening 53 in the upper surface S11 of the metal support 180. As shown in FIG. A first portion 51 of each through-hole 50 is formed in a first metal member 181 that constitutes the metal support 180 . In the first metal member 181, each first portion 51 penetrates from the upper surface S11 on the side of the electrolyte layer 112 in contact with the fuel electrode 116 to the lower surface S12 on the side opposite to the upper surface S11. From this, it can be said that the first portion 51 of each through-hole 50 extends in the Z-axis direction. Here, "stretching along a certain direction" means stretching substantially linearly in that direction, and an error of up to ±10° is allowed for the stretching direction. There may be (the same shall apply hereinafter).

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 S22 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 is positioned so that the contour line in the Z-axis direction view does not overlap the contour line of the first portion 51, and extends in the Z-axis direction.

Of the two contour lines (OL1, OL2) that define each through-hole 50 of the metal support 180, the contour line OL1, which is one (in the positive direction of the Y-axis in this embodiment), extends between the first extending portion OL11 and the second extending portion OL11. It has a first stepped portion OL10 including an extended portion OL12 and a third extended portion OL13.

A first extending portion OL11 of the contour OL1 of the metal support 180 extends from the end of the contour OL1 in the positive Z-axis direction. The first extending portion OL11 includes a portion extending along the Z-axis direction. It can be said that this "positive direction of the Z-axis" is the side of the electrolyte layer 112 in the Z-axis direction (the same applies hereinafter). In the present embodiment, the entire first extending portion OL11 extends along the Z-axis direction, but only a portion of the first extending portion OL11 may extend along the Z-axis direction. For example, when the surface (on the side of the electrolyte layer 112 in the Z-axis direction) defining the through hole 50 of the metal support 180 is chamfered, the surface of the first extending portion OL11 on the side of the electrolyte layer 112 in the Z-axis direction is chamfered. The end portion has a tapered shape extending in a direction inclined with respect to the Z-axis direction (the same applies when the second to sixth extension portions OL12, OL13, OL24, OL25, and OL26, which will be described later, are chamfered). In this embodiment, the first extending portion OL11 is a portion that defines the first portion 51 of the through hole 50 of the first metal member 181 . From the above, the first metal member 181 has a lower surface S12 including the second extending portion OL12, and a through hole (first portion 51) penetrating from the lower surface S12 in the Z-axis direction. It can be said. The through-hole (first portion 51) constitutes the electrolyte layer 112-side portion of the through-hole 50 defined by the first extending portion OL11.

The second extending portion OL12 of the contour line OL1 of the metal support 180 extends from the end of the first extending portion OL11 in the negative Z-axis direction. The second extending portion OL12 includes a portion extending along the Y-axis positive direction. In the present embodiment, the second extending portion OL12 extends entirely along the positive Y-axis direction, but only a portion thereof may extend along the positive Y-axis direction. . This "Y-axis positive direction" is a direction CFD ( hereinafter referred to as “centrifugal direction CFD”). In this embodiment, the second extending portion OL12 of the contour line OL1 of the metal support 180 is part of the lower surface S12 of the first metal member 181 . Further, it can be said that the centrifugal direction CFD (Y-axis positive direction) is the direction opposite to the flow direction (Y-axis negative direction) of the reactant gas (oxidant gas OG) in the fuel chamber 176 in the X-axis direction.

The third extending portion OL13 of the contour line OL1 of the metal support 180 extends from the end of the second extending portion OL12 in the positive Y-axis direction (centrifugal direction CFD). The third extending portion OL13 includes a portion extending along the Z-axis negative direction. In the present embodiment, the third extending portion OL13 extends entirely along the Z-axis negative direction, but only a portion thereof may extend along the Z-axis negative direction. . This "Z-axis negative direction" can be said to be the side opposite to the electrolyte layer 112 in the Z-axis direction (the same applies hereinafter). In this embodiment, the third extending portion OL13 is a portion that defines the second portion 52 of the through hole 50 . The second metal member 182 has an upper surface S21 that is joined to the lower surface S12 of the first metal member 181, and has a through hole (second portion 52) penetrating from the upper surface S21 in the Z-axis direction. ing. The through-hole (second portion 52) extends in the Z-axis negative direction (the side opposite to the electrolyte layer 112 in the Z-axis direction) of the through-hole 50 defined by the second extending portion OL12 and the third extending portion OL13. ).

The fuel electrode 116 includes, for each through-hole 50, a portion 118 (hereinafter referred to as "hole interior 118") that continues to the base portion 117 and is positioned within the through-hole 50. As shown in FIG. The hole interior 118 of the fuel electrode 116 is an example of the electrode hole interior in the claims. Each hole interior 118 has a portion 119 (hereinafter referred to as “specific portion 119”) located in the Z-axis negative direction (the side opposite to the electrolyte layer 112 in the Z-axis direction) with respect to the second extending portion OL12. is doing.

In this embodiment, the specific portion 119 of the anode 116 is bonded to the second extension OL12 of the metal support 180 .

The contour line OL2, which is the other of the two contour lines (OL1, OL2) that define each through-hole 50 of the metal support 180, is the fourth extension OL24, the fifth extension OL25, and the sixth extension OL26. and a second stepped portion OL20. The fourth extending portion OL24 extends from the end of the contour line OL2 in the Z-axis positive direction (the electrolyte layer 112 side in the Z-axis direction). The fourth extending portion OL24 includes a portion extending along the Z-axis direction. The fifth extending portion OL25 extends from the end of the fourth extending portion OL24 in the Z-axis negative direction (the side opposite to the electrolyte layer 112 in the Z-axis direction). The fifth extending portion OL25 includes a portion extending along the Y-axis positive direction. This "Y-axis positive direction" is the direction CPD (hereinafter referred to as "centripetal direction CPD") of the Y-axis direction that approaches the center of the electrolyte layer 112 side portion of the through-hole 50 defined by the fourth extending portion OL24. )You can say that. The sixth extending portion OL26 extends from the end of the fifth extending portion OL25 in the positive X-axis direction (centripetal direction CPD) along the negative Z-axis direction (opposite to the electrolyte layer 112 in the Z-axis direction). This is the part where

In this embodiment, anode 116 is bonded to fifth extension OL25 of metal support 180 .

Each through-hole 50 has a space SP in the inside 118 of each hole of the fuel electrode 116 in the Z-axis negative direction (on the side opposite to the electrolyte layer 112 in the Z-axis direction). The reaction gas (fuel gas FG) supplied to the fuel chamber 176 advances from the space SP through the gaps in each hole 118 of the fuel electrode 116, further advances through the gaps in the base 117 of the fuel electrode 116, supplied to the reaction field.

In addition, in the present embodiment, 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 single cell 110 having such a configuration can be manufactured, for example, by the following manufacturing method. First, the first metal member 181 and the second metal 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 metal member 181 by drilling. At the same time, the second portion 52 of each through-hole 50 is formed in the second metal member 182 . Next, the first metal member 181 and the second metal member 182 are arranged so that each first portion 51 communicates with each second portion 52, and the first step portion OL10 and the second step portion OL20 are formed. A metal support 180 is fabricated by aligning and joining, for example by welding, such that a is formed. In addition, in the present embodiment, when joining the first metal member 181 and the second metal member 182, the through hole (first portion 51) of the plate-like first metal member 181, The first stepped portion OL10 and the second stepped portion OL20 are easily realized (manufactured) by adjusting the relative position of the plate-shaped second metal member 182 with respect to the through hole (second portion 52). can do.

Next, pastes are prepared for forming each of the hole interior 118 and the base 117 of the fuel electrode 116 . Then, each through-hole 50 formed in the metal support 180 is filled with a paste for forming the inside of the hole 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 inside of the hole 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 S11 of the metal support 180 . The paste for forming hole interior 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. In this embodiment, the paste that forms the fuel electrode 116 is applied to the through hole (first portion 51) of the plate-like first metal member 181 and the plate-like second metal member 182. When forming the fuel electrode 116 by filling each of the through holes (second portion 52), the configuration of the electrode material (for example, filling amount and filling position) filled in each through hole (51, 52) ), the specific portion 119 of the anode 116 can be easily realized (manufactured).

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 . The metal support 180 is a member located on the side opposite to the electrolyte layer 112 with respect to the fuel electrode 116 . 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 fuel electrode 116 includes a hole interior 118 positioned within at least one of the plurality of through holes 50 (hereinafter referred to as "specific through hole"). In at least one section along the Z-axis direction of the unit cell 110 (for example, the section of the unit cell 110 shown in FIGS. 5 and 6; hereinafter referred to as the “specific section”), the specific through-hole of the metal support 180 is formed. The contour line OL1, which is one of the two contour lines (OL1, OL2) defining, forms a first stepped portion OL10 including a first extending portion OL11, a second extending portion OL12, and a third extending portion OL13. have. The first extending portion OL11 extends from the end of the contour line OL1 on the side of the electrolyte layer 112 in the Z-axis direction. The first extending portion OL11 includes a portion extending along the Z-axis direction. The second extension OL12 extends from the end of the first extension OL11 opposite to the electrolyte layer 112 in the Z-axis direction. The second extending portion OL12 extends away from the center of the electrolyte layer 112 side portion of the specific through-hole defined by the first extending portion OL11 in the Y-axis direction (direction intersecting the Z-axis direction). Including a portion extending along the direction CFD. The third extension OL13 extends from the end of the second extension OL12 in the centrifugal direction CFD. Third extending portion OL13 includes a portion extending along the side opposite to electrolyte layer 112 in the Z-axis direction. The hole interior 118 of the anode 116 has a specific portion 119 located on the opposite side of the electrolyte layer 112 in the Z-axis direction with respect to the second extension OL12.

In the single cell 110 of the present embodiment, as described above, the fuel electrode 116 has a hole interior 118 positioned within a specific through hole (at least one of the plurality of through holes 50). In the specific cross-section, the contour line OL1, which is one of the two contour lines (OL1, OL2) that define the specific through-hole of the metal support 180, is formed by the first extending portion OL11, the second extending portion OL12, and the second extending portion OL12. It has a first step OL10 with three extensions OL13. The hole inside 118 of the fuel electrode 116 extends in the centrifugal direction CFD (the direction away from the center of the unit cell 110 side portion of the specific through-hole defined by the first extending portion OL11 in the X-axis direction). It has a specific portion 119 located on the side opposite to the electrolyte layer 112 in the Z-axis direction with respect to the extended portion OL12. In the single cell 110 of the present embodiment, when a force (a force substantially parallel to the Z-axis direction) separating the first stepped portion OL10 of the metal support 180 and the specific portion 119 of the fuel electrode 116 is applied, the fuel electrode A specific portion 119 of 116 engages the first stepped portion OL10 of the metal support 180 to effectively function as an anchor. Therefore, according to the unit cell 110 of the present embodiment, the relative Z-axis direction between the fuel electrode 116 and the metal support 180 (more specifically, in the Z-axis direction, the fuel electrode 116 and the metal support 180 ) can be suppressed, and thus separation of the fuel electrode 116 from the metal support 180 can be suppressed.

Further, in the single cell 110 of the present embodiment, in the specific cross section, the specific portion 119 of the fuel electrode 116 (the portion located on the side opposite to the electrolyte layer 112 in the Z-axis direction with respect to the second extending portion OL12) is It is joined to the second extension OL12. As the length of the hole interior 118 of the fuel electrode 116 in the Z-axis direction increases, the flowability of the reaction gas (oxidant gas OG) through the through-hole 50 of the metal support 180 deteriorates, and eventually the single cell 110 generates power. Performance degrades. In the unit cell 110 of the present embodiment, as described above, in the specific cross section, the specific portion 119 of the fuel electrode 116 is positioned in the centrifugal direction CFD (in the Y-axis direction, the specific through-hole defined by the first extending portion OL11). The specific portion 119 of the fuel electrode 116 is joined to the portion extending along the Z-axis direction. The contact area between the fuel electrode 116 and the metal support 180 can be increased without increasing the length in the Z-axis direction of the inside 118 of the hole of the fuel electrode 116, as compared with the configuration in which the fuel electrode 116 and the metal support 180 are in contact. Therefore, according to the single cell 110 of the present embodiment, the deterioration of the power generation performance of the single cell 110 due to the flowability of the reactant gas through the through-holes 50 of the metal support 180 is suppressed, while the fuel electrode 116 and the metal support are The bonding strength with the body 180 can be improved.

Further, in the single cell 110 of the present embodiment, the specific through hole 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 single cell 110 of the present embodiment, as described above, the metal support 180 has the first stepped portion OL10 and the fuel electrode 116 has the specific portion 119. Separation of the fuel electrode 116 can be suppressed. According to the single cell 110 of the present embodiment, such an effect can be obtained. By having can be improved, and thus the power generation performance of the single cell 110 can be improved.

Also, the metal support 180 includes a first metal member 181 and a second metal member 182 . The first metal member 181 is a plate-like member, and has a lower surface S12 including the second extending portion OL12 and a through hole (first portion 51) penetrating from the lower surface S12 in the Z-axis direction. and a through-hole (first portion 51) that constitutes the electrolyte layer 112-side portion of the specific through-hole defined by one extending portion OL11. The second metal member 182 is a plate-like member having an upper surface S21 that is joined to the lower surface S12 of the first metal member 181, and has a through hole 52 penetrating from the upper surface S21 in the Z-axis direction. through-hole 52 forming a portion of the specific through-hole opposite to the electrolyte layer 112 defined by the extending portion OL12 and the third extending portion OL13. In the single cell 110 of the present embodiment, the first stepped portion OL10 is formed when the plate-shaped first metal member 181 and the second metal member 182 are joined together. can be easily realized (manufactured) by adjusting the relative position of the through hole (first portion 51) of the second metal member 182 and the through hole (second portion 52) of the plate-shaped second metal member 182 be able to. Further, the specific portion 119 of the fuel electrode 116 is formed by inserting a material (for example, paste, hereinafter referred to as “electrode material”) forming the fuel electrode 116 into the through hole (second 1 portion 51 ) and the through hole (second portion 52 ) of the plate-shaped second metal member 182 , and when forming the fuel electrode 116 , each through hole ( 51 , 52), the specific portion 119 of the fuel electrode 116 can be easily realized (manufactured) by adjusting the composition of the electrode material (for example, the filling amount and filling position).

In the specific cross section of the unit cell 110 of the present embodiment, the contour line OL2, which is the other of the two contour lines (OL1 and OL2) that define the specific through-hole of the metal support 180, is the fourth extending portion OL24. and a second stepped portion OL20 including a fifth extending portion OL25 and a sixth extending portion OL26. The fourth extending portion OL24 extends from the end of the contour line OL2 on the side of the electrolyte layer 112 in the Z-axis direction. The fourth extending portion OL24 includes a portion extending along the Z-axis direction. In the present embodiment, the fourth extending portion OL24 extends entirely along the Z-axis direction, but only a portion thereof may extend along the Z-axis direction. The fifth extension OL25 extends from the end of the fourth extension OL24 opposite to the electrolyte layer 112 in the Z-axis direction. The fifth extending portion OL25 extends along the centripetal direction CPD, which is the direction toward the center of the electrolyte layer 112 side portion of the specific through-hole defined by the fourth extending portion OL24, in the Y-axis direction. Including part. In the present embodiment, the fifth extending portion OL25 extends entirely along the centripetal direction CPD, but only a portion thereof may extend along the centripetal direction CPD. The sixth extension OL26 extends from the end of the fifth extension OL25 in the centripetal direction CPD. The sixth extending portion OL26 includes a portion extending along the side opposite to the electrolyte layer 112 in the Z-axis direction. In the present embodiment, the sixth extending portion OL26 extends entirely along the side opposite to the electrolyte layer 112 in the Z-axis direction, but only part of it extends along the side opposite to the electrolyte layer 112 in the Z-axis direction. may extend along opposite sides. The fuel electrode 116 is joined to the fifth extension OL25.

In the single cell 110 of the present embodiment, as described above, in a specific cross section, the fuel electrode 116 extends in the centripetal direction CPD (in the Y-axis direction, the electrolyte layer of the specific through-hole defined by the fourth extending portion OL24). 112 side portion) is joined to the fifth extension portion OL25 extending along the direction toward the center of the 112 side portion. Therefore, in the single cell 110 of the present embodiment, the portion of the fuel electrode 116 that is joined to the fifth extension portion OL25 of the metal support 180 is the portion that extends along the Z-axis direction of the specific through-hole. The contact area between the fuel electrode 116 and the metal support 180 can be increased without increasing the Z-axis length of the inside 118 of the hole 118 of the fuel electrode 116 compared to the bonded structure. Therefore, in the single cell 110 of the present embodiment, it is possible to more effectively suppress deterioration of the power generation performance of the single cell 110 due to the flowability of the reactant gas through the through-holes 50 of the metal support 180, and The bonding strength between 116 and metal support 180 can be improved.

The fuel cell stack 100 of this embodiment includes a plurality of power generation units 102 each having a single cell 110 and a fuel chamber 176 facing a fuel electrode 116, and arranged side by side in the Z-axis direction. In at least one power generation unit 102, the centrifugal direction CFD is in a direction opposite to the direction of gas flow in the fuel chamber 176 in the Y-axis direction. Therefore, in the fuel cell stack 100 of the present embodiment, the first stepped portion OL10 moves away from the center of the electrolyte layer 112 side portion of the specific through-hole defined by the first extended portion OL11 in the Y-axis direction. In this configuration, a first extension portion OL11, a second extension portion OL12, and a third extension portion OL13 are positioned in this order in the centrifugal direction CFD. Further, in the fuel cell stack 100 of the present embodiment, as described above, the centrifugal direction CFD is the direction opposite to the direction of gas flow in the fuel chamber 176 in the Y-axis direction. , the third extending portion OL13, the second extending portion OL12, and the first extending portion OL11 are positioned in this order in the direction of gas flow in the Y-axis direction. The order of arrangement of the third extending portion OL13, the second extending portion OL12, and the first extending portion OL11 is the direction of the gas flow in the Z-axis direction (the direction of the electrolyte layer 112 with respect to the metal support 180 in the Z-axis direction). direction). Therefore, according to the single cell 110 of the present embodiment, for example, a configuration in which the centrifugal direction CFD is the direction of gas flow (in other words, in the direction of gas flow, the first extending portion OL11, the second extending portion OL12, In comparison with the configuration in which the third extending portion OL13 is positioned in the order of the third extension portion OL13, etc., the flowability of the reaction gas passing through the specific through-hole can be improved, and the power generation performance of the single cell 110 can be improved.

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 different from that of the metal support. As long as the contour line OL1 of 180 has the first step portion OL10, it is not necessarily limited to this. For example, through hole 50 formed in metal support 180 may have a third portion communicating with second portion 52 in addition to first portion 51 and second portion 52 . Further, the third portion includes an extension portion extending in the Y-axis positive direction (the centrifugal direction CFD or the centripetal direction CPD) from the end of the third extension portion OL13 in the negative Z-axis direction, and a third stepped portion extending in the negative direction (opposite side of the electrolyte layer 112 in the Z-axis direction), or similarly having a fourth and subsequent stepped portions. Also good.

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 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. 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-described embodiment, the specific through-hole has the 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, but it is not necessarily limited to this. For example, the entire specific through-hole may be filled with the fuel electrode 116 .

In the above embodiment, (the contour line OL2 of) the metal support 180 has the second stepped portion OL20 comprising the fourth extending portion OL24, the fifth extending portion OL25, and the sixth extending portion OL26. It is not necessarily limited to this. For example, the contour line OL2 of the metal support 180 may be configured to include a seventh extending portion, an eighth extending portion, and a ninth extending portion, which will be described later. The seventh extending portion is a portion extending along the Z-axis direction from the edge of the contour line (one of the two contour lines) on the side of the electrolyte layer 112 in the Z-axis direction. The eighth extending portion extends from the end of the seventh extending portion opposite to the electrolyte layer 112 in the Z-axis direction by the seventh extending portion in the Y-axis direction (direction intersecting the Z-axis direction). It is a portion extending along the centrifugal direction, which is the direction away from the center of the electrolyte layer 112 side portion of the defined specific through-hole. The ninth extending portion is a portion extending from the centrifugal direction end of the eighth extending portion along the side opposite to the electrolyte layer 112 in the Z-axis direction.

In the above embodiment, the specific portion 119 of the fuel electrode 116 is joined to the second extension OL12 of the metal support 180, but it may not be joined, or may simply be in contact without being joined. It may be the same, or it may be separated.

In the above embodiment, the single cell 110 includes the metal support 180 located on the opposite side of the electrolyte layer 112 with respect to the fuel electrode 116, and (the outline OL1 of) the metal support 180 is the first The fuel electrode 116 has a first stepped portion OL10 comprising an extended portion OL11, a second extended portion OL12, and a third extended portion OL13, and the inside of the hole 118 of the fuel electrode 116 is located with respect to the second extended portion OL12. It has a specific portion 119 located on the opposite side of the electrolyte layer 112 in the Z-axis direction. Instead of or in addition to such a metal support 180, a configuration including an air electrode side metal support, which will be described later, may be adopted. That is, the single cell 110 includes a metal support (hereinafter referred to as "air electrode side metal support") located on the side opposite to the electrolyte layer 112 with respect to the air electrode 114, and has a specific cross section (single cell 110 along the Z-axis direction), one of the two contour lines of the air electrode side metal support has a stepped portion similar to the first stepped portion OL10 (hereinafter referred to as “air electrode side stepped portion ), and the air electrode 114 has a specific portion similar to the specific portion 119 (hereinafter referred to as “air electrode specific portion”). Specifically, the air electrode-side metal support has a plurality of through holes (hereinafter referred to as "air electrode side through holes") penetrating in the Z-axis direction at positions overlapping the air electrode 114 when viewed in the Z-axis direction. . The cathode-side stepped portion includes a tenth extension, an eleventh extension, and a twelfth extension, which will be described later. The tenth extending portion is a portion extending along the Z-axis direction from the edge of the contour line (one of the two contour lines) of the air electrode side metal support on the side of the electrolyte layer 112 in the Z-axis direction. be. The eleventh extending portion extends from the end of the tenth extending portion opposite to the electrolyte layer 112 in the Z-axis direction by the tenth extending portion in the X-axis direction (direction intersecting the Z-axis direction). It is a portion extending along the centrifugal direction, which is the direction away from the center of the electrolyte layer 112 side portion of the defined air electrode side specific through hole. The twelfth extending portion is a portion extending from the end of the eleventh extending portion in the centrifugal direction along the side opposite to the electrolyte layer 112 in the Z-axis direction. The air electrode 114 is located inside a hole (hereinafter referred to as "inside the air electrode hole") located in at least one of the air electrode side through holes (hereinafter referred to as "the air electrode side specific through hole"). and the interior of the cathode hole has a cathode specific portion. The air electrode specific portion is a portion located on the side opposite to the electrolyte layer 112 in the Z-axis direction with respect to the eleventh extending portion of the air electrode side metal support. In the configuration including the air electrode side metal support (and the air electrode 114 includes the inside of the air electrode hole) as described above, due to the presence of the air electrode side stepped portion of the air electrode side metal support and the air electrode specific portion, , the relative displacement in the Z-axis direction (more specifically, the direction in which the air electrode 114 and the air electrode-side metal support separate in the Z-axis direction) between the air electrode 114 and the air electrode-side metal support In addition, separation of the air electrode 114 from the air electrode side metal support can be suppressed. Similarly, other characteristic configurations of the above-described embodiments may be further employed in the above-described configuration including the air electrode side metal support (and the air electrode 114 includes the inside of the air electrode hole). 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.

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. 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.

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 (22A to 22E): 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, 106: End plate 108: Through hole 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 117: Base 118: Hole inside 119: Specific 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 metal member 182: Second metal member CFD: Centrifugal direction CPD: Centripetal direction FG: Fuel gas FOG: Fuel off-gas OG: Oxidant gas OL10: First step portion OL11: First extension portion OL12: Second extension portion OL13 : Third extension OL1: Contour OL20: Second step OL24: Fourth extension OL25: Fifth extension OL26: Sixth extension OL2: Contour OOG: Oxidant offgas 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. In an electrochemical reaction single cell comprising 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,
At least one of two contour lines that define the specific through-hole of the metal support,
a first extending portion extending from an end portion on the electrolyte layer side in the first direction, the first extending portion including a portion extending along the first direction;
a second extending portion extending from an end portion of the first extending portion opposite to the electrolyte layer in the first direction, the second extending portion extending in a second direction crossing the first direction; a second extending portion including a portion extending along a centrifugal direction, which is a direction away from the center of the electrolyte layer side portion of the specific through-hole defined by the first extending portion;
a third extension extending from the centrifugal end of the second extension and extending along a side opposite to the electrolyte layer in the first direction; a first stepped portion comprising a third extending portion;
The inside of the electrode hole has a specific portion located on the opposite side of the electrolyte layer in the first direction with respect to the second extending portion,
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to claim 1,
In the specific cross section,
The specific portion is joined to the second extension,
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to claim 1 or claim 2,
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 any one of claims 1 to 3,
The metal support is
A plate-shaped first metal member, comprising: a first surface including the second extending portion; and a through hole penetrating from the first surface in the first direction, wherein the first a plate-like first metal member having a through hole defined by an extending portion and forming the electrolyte layer-side portion of the specific through hole;
A plate-shaped second metal member having a second surface joined to the first surface, the through hole penetrating from the second surface in the first direction, a second metal member having a through-hole forming a portion of the specific through-hole opposite to the electrolyte layer defined by the extending portion of and the third extending portion;
An electrochemical reaction single cell characterized by: The electrochemical reaction single cell according to any one of claims 1 to 4,
In the specific cross section,
The other of the two contour lines that define the specific through-hole of the metal support,
a fourth extending portion extending from an end portion on the side of the electrolyte layer in the first direction, the fourth extending portion including a portion extending along the first direction;
A fifth extending portion extending from an end portion of the fourth extending portion opposite to the electrolyte layer in the first direction, wherein the fourth extending portion in the second direction a fifth extending portion including a portion extending along a centripetal direction, which is a direction approaching the center of the electrolyte layer side portion of the specific through-hole defined by a portion;
A sixth extension extending from the centripetal end of the fifth extension, the sixth extension extending along a side opposite to the electrolyte layer in the first direction. a second stepped portion comprising a sixth extension;
The specific electrode is joined to the fifth extension,
An electrochemical reaction single cell characterized by: A plurality of electric cells each having the electrochemical reaction unit cell according to any one of claims 1 to 5 and a gas chamber facing the specific electrode and arranged side by side in the first direction An electrochemical reaction cell stack comprising chemical reaction units,
in at least one of said electrochemical reaction units,
the centrifugal direction is opposite to the direction of gas flow in the gas chamber in the second direction;
An electrochemical reaction cell stack characterized by:

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