JP2024038678A - electrochemical reaction module - Google Patents

Abstract

To suppress occurrence of defects caused by a target element being contained in gas discharged from a discharge manifold, in a post-stage device to which the gas is supplied.SOLUTION: An electrochemical reaction module includes: a plurality of unit cells each including an electrolyte layer comprising a solid oxide and an air electrode and a fuel electrode facing each other with the electrolyte layer sandwiched therebetween; at least one manifold defining member; and a passage defining member. The at least one manifold defining member includes a manifold defining member with a first surface that defines a discharge manifold where gas flows, the gas passing through each cell-side gas passage facing a specific electrode which is one of the air electrode and the fuel electrode of each unit cell. The passage defining member contains a target element that is at least one of Mn and Fe, and has a surface defining an upstream gas passage located upstream of the discharge manifold. A specific compound including a specific element forming a compound with the target element exists on the first surface of the manifold defining member.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The technology disclosed herein relates to electrochemical reaction modules.

Solid oxide fuel cells (hereinafter referred to as "SOFC") are known as one type of fuel cells that generate electricity using an electrochemical reaction between hydrogen and oxygen. SOFCs are generally used in the form of a fuel cell module that includes a fuel cell stack in which a plurality of single cells are arranged in a predetermined direction.

The fuel cell stack is provided with an exhaust manifold for discharging gas. More specifically, the fuel cell stack is provided with at least one of an oxidant gas exhaust manifold through which gas that has passed through a cell-side gas flow passage facing the air electrode of each unit cell flows, and a fuel gas exhaust manifold through which gas that has passed through a cell-side gas flow passage facing the fuel electrode of each unit cell flows (see, for example, Patent Document 1). The gas exhausted from the exhaust manifold may be supplied to a downstream device (for example, a combustor, another fuel cell stack, or the fuel cell stack in which the exhaust manifold is formed).

Further, the fuel cell module is formed with an upstream gas flow path located upstream of the exhaust manifold. At least a portion of the upstream gas flow path is defined by the surface of the flow path defining member. The flow path defining member may be formed of a material containing a target element that is at least one of Mn and Fe.

JP2021-22560A

In a configuration in which the flow path defining member is formed of a material containing the target elements (Mn and/or Fe), when the fuel cell module reaches a high temperature (for example, 600°C or higher) during operation, the flow path defining member may The target element contained is scattered into the gas flowing through the upstream gas flow path. The gas flowing through the upstream gas flow path is discharged from the fuel cell stack via the discharge manifold, and then supplied to the above-mentioned downstream device. Therefore _{, the} target element will be contained in _the gas supplied to _the downstream device, and problems (for example, , clogging of the combustion nozzle in the combustor, and cracks in other fuel cell stacks or the electrolyte layer in the fuel cell stack.

Furthermore, this problem is solved when multiple electrolytic single cells, which are the constituent units of a solid oxide electrolytic cell (hereinafter referred to as "SOEC"), which generates hydrogen using the electrolysis reaction of water, are arranged side by side. This is a common problem for electrolytic cell modules including electrolytic cell stacks. In this specification, a fuel cell single cell and an electrolytic single cell are collectively referred to as an electrochemical reaction single cell, a fuel cell stack and an electrolytic cell stack are collectively referred to as an electrochemical reaction cell stack, and a fuel cell module is referred to as a fuel cell module. The electrolytic cell module and the electrochemical reaction module are collectively referred to as the electrochemical reaction module.

This specification discloses a technique that can solve the above-mentioned problems.

The technology disclosed in this specification can be realized, for example, as the following form.

(1) The electrochemical reaction module disclosed herein includes a plurality of electrochemical reaction unit cells, at least one manifold defining member, and a flow path defining member. Each of the plurality of electrochemical reaction single cells includes an electrolyte layer made of a solid oxide, and an air electrode and a fuel electrode that face each other with the electrolyte layer in between, and are arranged side by side in a predetermined direction. The at least one manifold defining member defines an exhaust manifold through which the gas that has passed through each cell-side gas flow path facing a specific electrode that is one of the air electrode and the fuel electrode of each electrochemical reaction single cell flows. A manifold defining member having a first surface. The flow path defining member includes a target element that is at least one of Mn and Fe, and has a surface that defines an upstream gas flow path located upstream with respect to the discharge manifold. A specific compound containing a specific element that forms a compound with the target element is present on the first surface of the manifold defining member.

In this electrochemical reaction module, a specific compound containing a specific element that forms a compound with a target element that is at least one of Mn and Fe is provided on the first surface of the manifold defining member that defines the discharge manifold. exist. Therefore, even if the target element contained in the flow path defining member scatters into the upstream gas flow path when the electrochemical reaction module is heated to a high temperature during operation, etc., it will be located downstream of the upstream gas flow path. In the discharge manifold, target elements can be captured by specific elements contained in specific compounds. Therefore, in the downstream device to which the gas discharged from the discharge manifold is supplied, it is possible to suppress the occurrence of problems caused by the inclusion of the target element in the gas.

(2) In the electrochemical reaction module, the manifold defining member having the first surface includes a metal part and a coat layer covering a surface of the metal part, and the coat layer is the first surface. The specific compound may be formed discretely on the surface of the substrate. By adopting this configuration, it is possible to disperse the stress caused by volumetric expansion and contraction during the reaction in which the target element is captured by the specific element contained in the specific compound, and as a result, the occurrence of cracks in the coating layer can be prevented. Can be suppressed.

(3) In the electrochemical reaction module, the metal portion may contain the specific element. If this configuration is adopted, the specific element can be continuously supplied from the metal part to the surface of the coating layer in the manifold defining member, and the target element capture function by the specific compound present on the surface of the coating layer can be continuously performed. can be maintained.

(4) In the electrochemical reaction module, the content ratio of the specific element on the surface of the coating layer may be larger than the content ratio of the specific element in the metal part. If this configuration is adopted, the target element can be effectively captured by the specific element on the surface of the coating layer.

(5) In the electrochemical reaction module, the at least one manifold defining member defines a manifold having a second surface defining a supply manifold that supplies gas to the cell side gas flow path of each electrochemical reaction unit cell. The specific compound may be present on the second surface of the manifold defining member. If this configuration is adopted, the target element in the gas supplied to the cell-side gas flow path of each electrochemical reaction single cell through the supply manifold can be captured by the specific compound present on the second surface, It is possible to suppress the occurrence of defects (for example, cracks in the electrolyte layer, etc.) caused by the scattering of the target element into the cell-side gas flow path.

Note that the technology disclosed in this specification can be realized in various forms, for example, in the form of an electrochemical reaction module (fuel cell module or electrolytic cell module) and its manufacturing method. is possible.

An explanatory diagram schematically showing the configuration of the fuel cell module 10 in this embodiment A perspective view showing the external configuration of a fuel cell stack 100 in this embodiment An explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. 2 An explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position IV-IV in FIG. 2 An explanatory diagram showing the YZ cross-sectional configuration of the fuel cell stack 100 at the position VV in FIG. 2 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. 3 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. 4 Explanatory diagram showing the detailed configuration of the fuel electrode side frame 140 Explanatory diagram showing the detailed configuration of the fuel electrode side frame 140

A. Embodiment:
A-1. Configuration of fuel cell module 10:
FIG. 1 is an explanatory diagram schematically showing the configuration of a fuel cell module 10 in this embodiment. The fuel cell module 10 includes a fuel cell stack 100 and other devices (such as a reformer/heater 330 described below). Below, the configuration of the fuel cell stack 100 will be explained first, and then the configurations of other devices that make up the fuel cell module 10 will be explained. The fuel cell module 10 is an example of an electrochemical reaction module in the claims.

A-2. Configuration of fuel cell stack 100:
FIG. 2 is a perspective view showing the external configuration of the fuel cell stack 100 in this embodiment. Further, FIG. 3 is an explanatory diagram showing an XZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. 2, and FIG. FIG. 2 is an explanatory diagram showing the configuration. FIG. 5 is an explanatory diagram showing a YZ cross-sectional configuration of the fuel cell stack 100 at the position VV in FIG. 2. As shown in FIG. Each figure shows mutually orthogonal XYZ axes for specifying directions (the same applies to other figures). In this specification, for convenience, the positive Z-axis direction will be referred to as the upward direction, and the negative Z-axis direction will be referred to as the downward direction, but the fuel cell stack 100 is actually oriented in a different direction. may be installed.

As shown in FIGS. 2 to 5, 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, a lower end separator 189, A pair of end plates 104 and 106 are provided. The seven power generation units 102 are arranged in a predetermined arrangement direction (vertical direction in this embodiment). One of the pair of end plates 104 and 106 (hereinafter referred to as "upper end plate 104") is arranged above the power generation block 103 composed of seven power generation units 102. , 106 (hereinafter referred to as the "lower end plate 106") is disposed below the lower end separator 189 disposed below the power generation block 103. The pair of end plates 104 and 106 are arranged to sandwich the power generation block 103 and the lower end separator 189 from above and below.

As shown in FIGS. 2 and 5, near the four corners of the outer periphery around the Z-axis direction of each layer (upper end plate 104, each power generation unit 102, lower end separator 189) constituting the fuel cell stack 100, Holes passing through each layer in the vertical direction are formed, and screw holes are formed in the upper surface near four corners of the outer periphery of the lower end plate 106 in the Z-axis direction. Corresponding holes formed in each of these layers communicate with each other in the vertical direction to form a bolt hole 109 extending in the vertical direction. In the following description, holes formed in each layer of the fuel cell stack 100 to constitute the bolt holes 109 may also be referred to as bolt holes 109.

A bolt 22 is inserted into each bolt hole 109. The lower end of each bolt 22 is threaded into a screw hole formed in the lower end plate 106, and a nut 24 is fitted into the upper end of each bolt 22. The lower surface of the nut 24 is in contact with the upper surface of the end plate 104 via the insulating sheet 26. Each layer of the fuel cell stack 100 is integrally fastened with the bolts 22 and nuts 24 having such a configuration. The insulating sheet 26 is made of, for example, a mica sheet, a ceramic fiber sheet, a ceramic powder sheet, a glass sheet, a glass-ceramic composite, or the like.

In addition, as shown in FIGS. 2 to 4, each layer is attached to the peripheral edge around the Z-axis direction of each layer (each power generation unit 102, lower end separator 189, lower end plate 106) constituting the fuel cell stack 100. Four holes penetrating in the vertical direction are formed, and the corresponding holes formed in each layer communicate with each other in the vertical direction, and a communication hole extends in the vertical direction from the uppermost power generation unit 102 to the lower end plate 106. 108. In the following description, the holes formed in each layer of the fuel cell stack 100 to constitute the communication holes 108 may also be referred to as the communication holes 108.

As shown in FIGS. 2 and 3, one communication hole 108 introduces oxidizing gas OG from outside the fuel cell stack 100 and supplies the oxidizing gas OG to an air chamber 166 (described later) of each power generation unit 102. The other communication hole 108 functions as an air electrode side supply manifold 161 which is a gas flow path for the fuel cell stack 100 . It functions as an air electrode side exhaust manifold 162 which is a gas flow path for exhausting to the outside. For example, air is used as the oxidant gas OG. The air electrode side supply manifold 161 is an example of the supply manifold in the claims, and the air electrode side discharge manifold 162 is an example of the exhaust manifold in the claims.

Further, as shown in FIGS. 2 and 4, the other communication hole 108 introduces fuel gas FG from the outside of the fuel cell stack 100, and transfers the fuel gas FG to a fuel chamber 172 (described later) of each power generation unit 102. The other communication hole 108 functions as a fuel electrode side supply manifold 171 which is a gas flow path for supplying gas to the fuel cell stack 100 . It functions as a fuel electrode side exhaust manifold 172, which is a gas flow path for exhausting gas to the outside. As the fuel gas FG, for example, a hydrogen-rich gas obtained by reforming city gas is used. The fuel electrode side supply manifold 171 is an example of the supply manifold in the claims, and the fuel electrode side exhaust manifold 172 is an example of the exhaust manifold in the claims.

Note that in this specification, a member having a surface that defines at least a portion of each manifold 161, 162, 171, 172 is referred to as a manifold defining member. In this embodiment, the manifold defining members include the lower end plate 106, the lower end separator 189, and each member constituting the power generation unit 102 (a single cell separator 120, an air electrode frame 130, and a fuel electrode frame to be described later). 140, an interconnector separator 180).

The fuel cell stack 100 is provided with four gas passage members 27. Each gas passage member 27 has a hollow cylindrical main body 28 and a hollow cylindrical branch 29 branching from a side surface of the main body 28 . The hole in the branch portion 29 communicates with the hole in the main body portion 28 . A gas pipe (not shown) is connected to the branch portion 29 of each gas passage member 27. As shown in FIG. 3, the holes in the main body 28 of the gas passage member 27 disposed at the position of the air electrode side supply manifold 161 communicate with the air electrode side supply manifold 161, and the holes in the air electrode side exhaust manifold 162 communicate with the air electrode side supply manifold 161. A hole in the main body portion 28 of the gas passage member 27 located at the position communicates with the air electrode side discharge manifold 162. Further, as shown in FIG. 4, the hole in the main body 28 of the gas passage member 27 disposed at the position of the fuel electrode side supply manifold 171 communicates with the fuel electrode side supply manifold 171, and A hole in the main body portion 28 of the gas passage member 27 located at a position 172 communicates with the fuel electrode side exhaust manifold 172. Note that an insulating sheet 26 is interposed between each gas passage member 27 and the surface of the lower end plate 106.

(Configuration of end plates 104, 106)
As shown in FIGS. 2 to 5, the pair of end plates 104 and 106 are flat plate-like members having a substantially rectangular outer shape when viewed in the Z-axis direction, and are made of a conductive material such as stainless steel. Holes 32 and 34 passing through in the Z-axis direction are formed near the center of the pair of end plates 104 and 106. When viewed in the Z-axis direction, the outlines of the holes 32 and 34 formed in the pair of end plates 104 and 106 include each single cell 110, which will be described later. Therefore, the compressive force in the Z-axis direction generated by fastening with each bolt 22 and nut 24 mainly acts on the peripheral portion of each power generation unit 102 (the portion on the outer peripheral side of each single cell 110, which will be described later). Further, in this embodiment, the upper end plate 104 functions as a positive output terminal of the fuel cell stack 100, and the lower end plate 106 functions as a negative output terminal of the fuel cell stack 100.

(Configuration of lower end separator 189)
As shown in FIGS. 3 to 5, the lower end separator 189 is a flat member having a substantially rectangular outer shape when viewed in the Z-axis direction, and is made of, for example, metal. The peripheral edge of the lower end separator 189 is sandwiched between the power generation block 103 and the lower end plate 106 and joined to the lower end plate 106 by, for example, welding, and is electrically connected to the lower end plate 106. It is connected to the.

(Configuration of power generation unit 102)
FIG. 6 is an explanatory diagram showing an 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. 3, and FIG. FIG. 2 is an explanatory diagram showing an XZ cross-sectional configuration of two power generation units 102. FIG.

As shown in FIGS. 6 and 7, the power generation unit 102 includes a fuel cell single cell (hereinafter referred to as "single cell") 110, a single cell separator 120, and the top and bottom layers of the power generation unit 102. A pair of interconnectors 190, an interconnect separator 180, an air electrode frame 130, a fuel electrode frame 140, and a fuel electrode current collector 144 are provided. Communication holes 108 functioning as manifolds 161, 162, 171, and 172 are provided at the peripheral edges of the single cell separator 120, the air electrode frame 130, the fuel electrode frame 140, and the interconnector separator 180 in the Z-axis direction. A hole that constitutes each bolt hole 109 and a hole that constitutes each bolt hole 109 are formed.

The single cell 110 includes an electrolyte layer 112, an air electrode 114 and a fuel electrode 116 facing each other in the Z-axis direction with the electrolyte layer 112 in between, and an intermediate layer 118 disposed between the electrolyte layer 112 and the air electrode 114. Equipped with Note that the single cell 110 of this embodiment is a fuel electrode supported type single cell in which the fuel electrode 116 supports other layers (electrolyte layer 112, air electrode 114, intermediate layer 118) that constitute the single cell 110. The single cell 110 is an example of an electrochemical reaction single cell in the claims.

The electrolyte layer 112 is a substantially rectangular plate-shaped member when viewed in the Z-axis direction, and is configured to include a solid oxide (for example, stabilized zirconia such as YSZ (yttria stabilized zirconia)). That is, the single cell 110 of this embodiment is a solid oxide fuel cell (SOFC) that uses a solid oxide as an electrolyte. The air electrode 114 is a substantially rectangular flat plate member smaller than the electrolyte layer 112 when viewed in the Z-axis direction, and is configured to include, for example, a perovskite oxide (for example, LSCF (lanthanum strontium cobalt iron oxide)). . The fuel electrode 116 is a substantially rectangular plate-shaped member having substantially the same size as the electrolyte layer 112 when viewed in the Z-axis direction, and is formed of, for example, Ni (nickel), a cermet made of Ni and ceramic particles, a Ni-based alloy, or the like. ing. The intermediate layer 118 is a substantially rectangular plate-shaped member having substantially the same size as the air electrode 114 when viewed in the Z-axis direction, and is configured to include, for example, GDC (gadolinium-doped ceria) and YSZ. The intermediate layer 118 has a structure in which an element (e.g., Sr) diffused from the air electrode 114 reacts with an element (e.g., Zr) contained in the electrolyte layer 112 to generate a high-resistance substance (e.g., SrZrO ₃ ). It has a suppressing function.

The single cell separator 120 is a frame-shaped member in which a substantially rectangular through hole 121 that penetrates in the vertical direction is formed near the center, and is made of, for example, metal. A portion of the single cell separator 120 surrounding the through hole 121 (hereinafter referred to as "through hole surrounding area") faces the upper surface of the peripheral edge of the single cell 110 (electrolyte layer 112). The single cell separator 120 is joined to the single cell 110 (electrolyte layer 112) by a joint 124 formed of a brazing material (for example, Ag solder) disposed at opposing portions. The single cell separator 120 separates an air chamber 166 facing the air electrode 114 and a fuel chamber 176 facing the fuel electrode 116, and gas flows from one electrode side to the other electrode side at the peripheral edge of the single cell 110. leaks (cross leaks) are suppressed.

The single cell separator 120 has an inner part 126 including the area around the through hole of the single cell separator 120, an outer part 127 located on the outer peripheral side than the inner part 126, and a connection connecting the inner part 126 and the outer part 127. 128. In this embodiment, the inner part 126 and the outer part 127 have a substantially flat plate shape extending in a direction substantially perpendicular to the Z-axis direction. Further, the connecting portion 128 has a curved shape so as to protrude downward from both the inner portion 126 and the outer portion 127. The lower portion (fuel chamber 176 side) of the connecting portion 128 is a convex portion, and the upper portion (air chamber 166 side) of the connecting portion 128 is a recessed portion. Therefore, the connecting portion 128 includes a portion whose position in the Z-axis direction is different from that of the inner portion 126 and the outer portion 127.

A glass seal portion 125 containing glass is arranged near the through hole 121 in the single cell separator 120. The glass seal part 125 is located on the air chamber 166 side with respect to the joint part 124, and is located on the surface around the through hole of the single cell separator 120 and the surface of the single cell 110 (in this embodiment, the electrolyte layer 112). It is formed so that it comes into contact with both. The glass seal portion 125 effectively suppresses the above-mentioned cross leak.

The interconnector 190 is a conductive member having a substantially rectangular flat plate portion 150 and a plurality of substantially columnar air electrode side current collecting portions 134 protruding from the flat plate portion 150 toward the air electrode 114, For example, it is made of ferritic stainless steel. A conductive coating layer 194 made of, for example, spinel-type oxide is formed on at least a portion of the surface of the interconnector 190 facing the air chamber 166. Further, an oxide film 198 is formed on at least a portion of the surface of the interconnector 190 facing the fuel chamber 176. The oxide film 198 is composed of an inner layer containing, for example, Cr ₂ O ₃ (chromia) and an outer layer containing, for example, MnCr ₂ O ₄ . Hereinafter, the interconnector 190 covered with the coating layer 194 and the oxide film 198 will be simply referred to as interconnector 190. Interconnector 190 contains a target element that is at least one of Mn and Fe. Note that interconnector 190 has a surface that defines a portion of fuel chamber 176. The fuel chamber 176 is an upstream gas flow path located upstream of the fuel electrode side exhaust manifold 172. Therefore, the interconnector 190 corresponds to a flow path defining member having a surface that defines an upstream gas flow path.

In each power generation unit 102, the upper interconnector 190 is arranged above the single cell 110. Each air electrode side current collector part 134 of the upper interconnector 190 is bonded to the air electrode 114 of the single cell 110 via a conductive bonding material 196 made of, for example, spinel oxide. It is electrically connected to the air electrode 114 of the cell 110. In each power generation unit 102, the lower interconnector 190 is arranged below the single cell 110, and connects the fuel electrode 116 of the single cell 110 via a fuel electrode side current collector 144, which will be described later. electrically connected to. The interconnector 190 ensures electrical continuity between the power generation units 102 and suppresses mixing of reaction gases between the power generation units 102. Note that in this embodiment, when two power generation units 102 are arranged adjacent to each other, one interconnector 190 is shared by the two adjacent power generation units 102. That is, the upper interconnector 190 in a certain power generation unit 102 is the same member as the lower interconnector 190 in another power generation unit 102 adjacent to the upper side of the power generation unit 102. Furthermore, since the fuel cell stack 100 includes a lower end separator 189, the lowest power generation unit 102 in the fuel cell stack 100 does not include a lower interconnector 190 (see FIGS. 3 to 5). .

The interconnector separator 180 is a frame-shaped member in which a substantially rectangular through hole 181 penetrating vertically is formed near the center, and is made of metal, for example. A portion of the interconnector separator 180 surrounding the through hole 181 (hereinafter referred to as the “through hole surrounding portion”) is joined to the upper surface of the peripheral portion of the flat plate portion 150 of the interconnector 190 by, for example, welding. Among the pair of interconnector separators 180 included in a certain power generation unit 102, the upper interconnector separator 180 connects the air chamber 166 of the power generation unit 102 and the other power generation unit adjacent above to the power generation unit 102. The fuel chamber 176 of the unit 102 is partitioned. In addition, among the pair of interconnector separators 180 included in a certain power generation unit 102, the lower interconnector separator 180 is adjacent to the fuel chamber 176 of the power generation unit 102 on the lower side with respect to the power generation unit 102. The air chambers 166 of other power generation units 102 that match the air chambers 166 are separated. In this way, the interconnector separator 180 suppresses gas leakage between the power generation units 102 at the periphery of the power generation units 102. Note that the interconnect separator 180 joined to the upper interconnector 190 of the uppermost power generation unit 102 in the fuel cell stack 100 is electrically connected to the upper end plate 104.

The interconnector separator 180 has an inner part 186 including the area around the through hole of the interconnector separator 180, an outer part 187 located on the outer peripheral side than the inner part 186, and a connection that connects the inner part 186 and the outer part 187. 188. In this embodiment, the inner part 186 and the outer part 187 have a substantially flat plate shape extending in a direction substantially perpendicular to the Z-axis direction. Further, the connecting portion 188 has a curved shape so as to protrude downward from both the inner portion 186 and the outer portion 187. The lower portion (air chamber 166 side) of the connecting portion 188 is a convex portion, and the upper portion (fuel chamber 176 side) of the connecting portion 188 is a recessed portion. Therefore, the connecting portion 188 includes a portion whose position in the Z-axis direction is different from that of the inner portion 186 and the outer portion 187.

The air electrode side frame 130 is a frame-like member in which a substantially rectangular hole 131 is formed near the center and penetrates in the vertical direction, and is made of an insulator such as mica, for example. The hole 131 of the air electrode side frame 130 constitutes an air chamber 166 facing the air electrode 114. The air electrode side frame 130 is in contact with the upper surface of the periphery of the single cell separator 120 and the lower surface of the periphery of the upper interconnector separator 180, thereby ensuring gas sealing between the two. (that is, the gas sealing property of the air chamber 166). Moreover, the air electrode side frame 130 electrically insulates between the pair of interconnector separators 180 (that is, between the pair of interconnectors 190) included in the power generation unit 102. The air electrode side frame 130 includes an air electrode side supply communication flow path 132 that communicates between the air electrode side supply manifold 161 and the air chamber 166, and an air electrode side exhaust that communicates between the air chamber 166 and the air electrode side discharge manifold 162. A communication channel 133 is formed. A space (gas flow path) including the air chamber 166, the air electrode side supply communication flow path 132, and the air electrode side discharge communication flow path 133 is an example of the cell side gas flow path in the claims.

The fuel electrode side frame 140 is a frame-shaped member in which a substantially rectangular hole 141 that vertically penetrates is formed near the center, and is made of metal, for example. The hole 141 of the fuel electrode side frame 140 constitutes a fuel chamber 176 facing the fuel electrode 116. The fuel electrode side frame 140 is in contact with the lower surface of the periphery of the single cell separator 120 and the upper surface of the periphery of the lower interconnector separator 180. The fuel electrode side frame 140 includes a fuel electrode side supply communication channel 142 that communicates between the fuel electrode side supply manifold 171 and the fuel chamber 176, and a fuel electrode side exhaust that communicates between the fuel chamber 176 and the fuel electrode side exhaust manifold 172. A communication channel 143 is formed. A space (gas flow path) that is a combination of the fuel chamber 176, the fuel electrode side supply communication flow path 142, and the fuel electrode side discharge communication flow path 143 is an example of the cell side gas flow path in the claims.

The fuel electrode side current collector 144 is arranged within the fuel chamber 176. The fuel electrode side current collector 144 includes an interconnector facing part 146, an electrode facing part 145, and a connecting part connecting the electrode facing part 145 and the interconnector facing part 146, and is made of, for example, nickel, nickel alloy, It is made of stainless steel or the like. Electrode facing portion 145 is in contact with the lower surface of fuel electrode 116 , and interconnector facing portion 146 is in contact with the upper surface of interconnector 190 . However, as described above, since the power generation unit 102 located at the lowest position in the fuel cell stack 100 does not include the lower interconnector 190, the interconnector of the fuel electrode side current collector 144 in the power generation unit 102 The portion 146 is in contact with the lower end separator 189. Since the fuel electrode side current collector 144 has such a configuration, it electrically connects the fuel electrode 116 and the interconnector 190 (or the lower end separator 189). Note that a spacer 149 made of mica, for example, is arranged between the electrode facing part 145 of the fuel electrode side current collecting part 144 and the interconnector facing part 146. Therefore, the fuel electrode side current collector 144 follows the deformation of the power generation unit 102 due to temperature cycles and reaction gas pressure fluctuations, and connects the fuel electrode 116 via the fuel electrode side current collector 144 to the interconnector 190 (or lower end separator 189). ) maintains a good electrical connection.

A-3. Configuration of devices other than fuel cell stack 100 in fuel cell module 10:
Next, the configuration of devices other than the fuel cell stack 100 in the fuel cell module 10 will be described. As shown in FIG. 1, the fuel cell module 10 includes an auxiliary device 300 including an evaporator 310 and a reformer/heater 330, and various flow paths connecting each device. Each device (fuel cell stack 100, auxiliary device 300) is housed in a heat insulating space 351 surrounded by a heat insulating material 350. Note that in FIG. 1, for convenience, the heat insulating material 350 has a simple rectangular shape that covers the periphery of all the devices, but in reality, it covers the periphery of all the devices and also covers the periphery of each device. ing. In Figure 1, the flow of gas on the fuel electrode side (including raw fuel gas RFG, fuel gas FG, and fuel off-gas FOG) is shown by a dashed-dotted line, and the flow of gas on the air electrode side (including oxidant gas OG and oxidant off-gas OOG) is shown by a dashed line. (including) is shown by a solid line, the flow of exhaust gas EG is shown by a broken line, and the flow of water is shown by a two-dot chain line.

The evaporator 310 is a box-shaped member with a space formed inside, and is made of metal, for example. Evaporator 310 is a device for evaporating water WA to generate water vapor. A pure water introduction channel 251 for introducing water WA is connected to the evaporator 310. The pure water introduction channel 251 is mainly composed of piping, and on the pure water introduction channel 251, an ion exchange resin (not shown), a purified water tank/float, and a flow rate control mechanism are provided. . The water WA supplied from the water supply source to the pure water introduction channel 251 undergoes removal of calcium ions, etc. in an ion exchange resin, is purified and stored in a water purification tank/float, and at a flow rate controlled by a flow rate control mechanism. It is introduced into the evaporator 310 as pure water.

Further, a raw fuel gas introduction channel 261 for introducing raw fuel gas RFG is connected to the evaporator 310. The raw fuel gas introduction channel 261 is mainly constituted by piping, and a flow rate control mechanism and a hydrogen desulfurizer (both not shown) are provided on the raw fuel gas introduction channel 261. The raw fuel gas RFG supplied from the gas source to the raw fuel gas introduction channel 261 is introduced into the evaporator 310 at a flow rate controlled by the flow rate control mechanism, with sulfur components removed in the hydrodesulfurizer. .

The evaporator 310 also includes an exhaust gas relay passage 226 for sending exhaust gas EG from a housing 335 (described later) of the reformer/heater 330 to the evaporator 310, and a reformer/heater 330 from the evaporator 310 to the reformer/heater 330. A mixed gas flow path 228 for sending mixed gas to the gas generator 331 (described later) and an exhaust gas exhaust flow path (not shown) for exhausting exhaust gas EG from the evaporator 310 are connected. These channels are mainly composed of piping.

The reformer/heater 330 includes a reformer 331, a combustor 333, and a housing 335. The housing 335 is a closed container made of metal, for example, and houses the reformer 331 and the combustor 333. The housing 335 has a double wall structure having an inner wall 336 and an outer wall 337, and heat transfer fins 339 are arranged in an air passage 338 formed between the inner wall 336 and the outer wall 337. There is. Note that in FIG. 1, illustration of a part of the heat transfer fins 339 is omitted. An air introduction channel 271 for introducing oxidant gas OG (air) is connected to the housing 335. The air introduction channel 271 is mainly composed of piping, and a flow rate control mechanism (not shown) is provided on the air introduction channel 271. The oxidant gas OG supplied to the air introduction channel 271 is introduced into the air channel 338 of the housing 335 at a flow rate controlled by the flow rate control mechanism. Furthermore, an air electrode side gas supply channel 61 for sending out oxidant gas OG toward the air electrode side supply manifold 161 of the fuel cell stack 100 is connected to the housing 335 . The air electrode side gas supply channel 61 is mainly composed of piping.

The reformer 331 is a box-shaped member with a space formed inside, and is made of metal, for example. The reformer 331 is a device for reforming (steam reforming) raw fuel gas RFG to generate fuel gas FG. A catalyst is disposed within the reformer 331 to promote the reforming reaction. As described above, the mixed gas flow path 228 for sending mixed gas from the evaporator 310 to the reformer 331 is connected to the reformer 331 . Further, a fuel electrode side gas supply flow path 71 for sending fuel gas FG toward the fuel electrode side supply manifold 171 of the fuel cell stack 100 is connected to the reformer 331 . The fuel electrode side gas supply channel 71 is mainly composed of piping.

The combustor 333 is a box-shaped member with a space formed inside, and is made of metal, for example. The combustor 333 is a device for burning the oxidant offgas OOG and the fuel offgas FOG. A catalyst may be disposed within the combustor 333 to promote combustion of the oxidant offgas OOG and the fuel offgas FOG. The combustor 333 includes an air electrode side gas exhaust passage 240 through which oxidizing agent off gas OOG is sent out from the air electrode side exhaust manifold 162 of the fuel cell stack 100 and a fuel off gas FOG from the fuel electrode side exhaust manifold 172 of the fuel cell stack 100. It is connected to a fuel electrode side gas exhaust channel 230 through which gas is sent out. These channels are mainly composed of piping.

A-4. Operation of fuel cell module 10:
Next, the operation of the fuel cell module 10 will be explained. As shown in FIG. 1, the oxidizing gas OG is introduced into the air flow path 338 formed in the housing 335 of the reformer/heater 330 via the air introduction flow path 271. The oxidant gas OG introduced into the air flow path 338 flows through the air flow path 338 while being heated by the combustion heat generated by the combustor 333, and in a state where the temperature has increased, it passes through the air electrode side gas supply flow path 61. The air is supplied to the air electrode side supply manifold 161 of the fuel cell stack 100 via the fuel cell stack 100. As shown in FIGS. 3 and 6, the oxidizing gas OG supplied to the air electrode side supply manifold 161 is supplied to the air chamber 166 via the air electrode side supply communication passage 132 of each power generation unit 102.

Further, as shown in FIG. 1, raw fuel gas RFG is supplied to the evaporator 310 via the raw fuel gas introduction channel 261, and water WA is supplied to the evaporator 310 via the pure water introduction channel 251. Then, in the evaporator 310, water vapor is generated by evaporating the water WA using the heat of the exhaust gas EG introduced via the exhaust gas relay flow path 226, and this water vapor is combined with the raw fuel gas RFG. mixed. The raw fuel gas RFG mixed with water vapor is introduced from the evaporator 310 to the reformer 331 via the mixed gas flow path 228, and is reformed with steam in the reformer 331. As a result, the hydrogen-rich fuel gas FG is generated. The generated fuel gas FG is supplied to the fuel electrode side supply manifold 171 of the fuel cell stack 100 via the fuel electrode side gas supply flow path 71. As shown in FIGS. 4 and 7, the fuel gas FG supplied to the fuel electrode side supply manifold 171 is supplied to the fuel chamber 176 via the fuel electrode side supply communication passage 142 of each power generation unit 102.

When the oxidant gas OG is supplied to the air chamber 166 of each power generation unit 102 and the fuel gas FG is supplied to the fuel chamber 176, the oxygen contained in the oxidant gas OG and the fuel gas Electric power is generated through an electrochemical reaction with hydrogen contained in FG. 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 190, and the fuel electrode 116 is electrically connected to the other interconnector 190 via the fuel electrode side current collector 144. has been done. Further, 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 extracted from the end plates 104 and 106 that function as output terminals of the fuel cell stack 100. Note that SOFCs generate electricity at relatively high temperatures (for example, 700°C to 1000°C).

As shown in FIGS. 1, 3, and 6, the oxidant off-gas OOG discharged from the air chamber 166 of each power generation unit 102 to the air electrode side exhaust manifold 162 via the air electrode side exhaust communication flow path 133 is The gas is introduced from the battery stack 100 into the combustor 333 via the air electrode side gas exhaust flow path 240. In addition, as shown in FIGS. 1, 4, and 7, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102 to the fuel electrode side exhaust manifold 172 via the fuel electrode side exhaust communication passage 143 is The gas is introduced from the fuel cell stack 100 into the combustor 333 via the fuel electrode side gas exhaust flow path 230. The oxidant offgas OOG and fuel offgas FOG introduced into the combustor 333 are mixed and combusted in the combustor 333, and then discharged as exhaust gas EG to the evaporator 310 via the exhaust gas relay flow path 226. Note that the heat generated in the combustor 333 accelerates the reforming reaction in the reformer 331 and heats the fuel cell stack 100.

A-5. Detailed configuration of fuel electrode side frame 140:
8 and 9 are explanatory diagrams showing the detailed configuration of the fuel electrode side frame 140. FIG. 8 shows an enlarged view of the configuration of the X1 section in FIG. 7, and FIG. 9 shows an enlarged view of the configuration of the X2 section in FIG.

As described above, the fuel electrode frame 140 is a manifold defining member having a surface that defines at least a portion of the manifold. More specifically, as shown in FIG. 8, the anode frame 140 has a first surface 41 that defines an anode exhaust manifold 172 that exhausts fuel off-gas FOG. Further, as shown in FIG. 9, the fuel electrode side frame 140 has a second surface 42 that defines a fuel electrode side supply manifold 171 that supplies the fuel gas FG.

As shown in FIGS. 8 and 9, the fuel electrode side frame 140 includes a metal portion 140a and a coat layer 140b covering the surface of the metal portion 140a. The metal portion 140a is made of, for example, ferritic stainless steel. Coat layer 140b includes an inner layer 140c and an outer layer 140d that covers the outside of inner layer 140c. The first surface 41 and the second surface 42 described above are the surfaces of the coat layer 140b (outer layer 140d). The inner layer 140c is made of, for example, Cr ₂ O ₃ (chromia), and the outer layer 140d is made of, for example, Al ₂ O ₃ (alumina). By forming the outer layer 140d from alumina, it is possible to effectively suppress Cr contained in the metal portion 140a from scattering into the manifold.

As shown in FIG. 8 , a specific compound 43 is present on the first surface 41 of the fuel electrode frame 140 that defines the fuel electrode exhaust manifold 172 . The specific compound 43 is a compound containing a specific element that forms a compound with the above-mentioned target element (at least one of Mn and Fe). Specific elements include, for example, Ti and S, and specific compounds include, for example, TiO ₂ (titania) and Al ₂ (SO ₄ ) ₃ (aluminum sulfate). As shown in FIG. 8, on the first surface 41 of the fuel electrode side frame 140, specific compounds 43 are formed discretely (in the form of islands). Since the specific compound 43 includes a specific element that forms a compound with the target element, if the target element (for example, Mn) is contained in the fuel off-gas FOG flowing through the fuel electrode side exhaust manifold 172, the target element will be present on the first surface 41. It is captured by the specific compound 43 present.

Similarly, as shown in FIG. 9, the specific compound 43 is also present on the second surface 42 defining the fuel electrode side supply manifold 171 in the fuel electrode side frame 140. On the second surface 42 of the fuel electrode side frame 140, specific compounds 43 are formed discretely (in the form of islands). When the target element (for example, Mn) is contained in the fuel gas FG flowing through the fuel electrode side supply manifold 171, the target element is captured by the specific compound 43 present on the second surface 42.

Note that in this embodiment, the metal portion 140a of the fuel electrode side frame 140 contains a specific element. However, the content ratio of the specific element on the surface of the coating layer 140b of the fuel electrode side frame 140 is larger than the content ratio of the specific element on the metal part 140a. The content ratio of the specific element on the surface of the coating layer is determined by measuring any 10 points in the field of view magnified by 1000 times or less (for example, 1000 times) using EDS (energy dispersive X-ray spectroscopy). This is the average value of the content ratio of specific elements at 10 locations when point analysis is performed. Specifically, the content ratio of the specific element can be defined as the percentage of the specific element when the sum of the mass concentrations of inorganic elements other than oxygen detected by point analysis is taken as 100%. In addition, regarding the content ratio of a specific element in a metal part, when 10 arbitrary points are point-analyzed in a field of view magnified by 1000 times or less (for example, 1000 times) of the cross section of the metal part using EDS, 10 points are determined. This is the average value of the content ratio of a specific element. The content rate of the specific element is determined in the same way as the content rate of the specific element on the surface of the coating layer.

The fuel electrode side frame 140 having such a configuration, for example, heat-treats (for example, 1000° C. in the atmosphere for 10 hours) a ferritic stainless steel base material containing Al, Cr, and specific elements at predetermined concentrations. It can be manufactured by That is, by such heat treatment, an inner layer 140c and an outer layer 140d are formed in the metal part 140a, and furthermore, a specific element is precipitated as an oxide from the grain boundaries of particles constituting the outer layer 140d, and island-like islands are formed on the surface of the outer layer 140d. A specific compound 43 is formed. However, as a method for manufacturing the fuel electrode side frame 140, other methods (for example, a method of applying and adhering the specific compound 43 to the surface of the fuel electrode side frame 140, etc.) may be adopted.

A-6. Example:
A sample fuel cell stack 100 was produced. At this time, titania as the specific compound 43 was placed on the surface of the fuel electrode side frame 140 that defines the manifold. A durability test was conducted on this fuel cell stack 100 at 850° C. for 2000 hours. The fuel utilization rate was 82%, and the current density was 0.47 A/cm ² . After the durability test, the fuel cell stack 100 was disassembled and EDS mapping of the surface defining the manifold in the fuel electrode side frame 140 was performed, and it was found that the mapping positions of Mn and Ti overlapped. Therefore, it was confirmed that Mn, which is the target element in the gas flowing through the manifold, can be captured by the specific compound 43.

Further, a similar durability test was conducted using another sample of the fuel cell stack 100, and when EDS mapping of the surface defining the manifold in the fuel electrode side frame 140 was performed, the mapping positions of Fe and Ti overlapped. Therefore, it was confirmed that Fe, which is the target element in the gas flowing through the manifold, can be captured by the specific compound 43.

A-7. Effects of this embodiment:
As described above, the fuel cell module 10 of the present embodiment includes a plurality of single cells 110 arranged in a predetermined direction, a fuel electrode side frame 140 that is a manifold defining member, and an interface that is a flow path defining member. A connector 190 is provided. Each unit cell 110 includes an electrolyte layer 112 made of solid oxide, and an air electrode 114 and a fuel electrode 116 facing each other with the electrolyte layer 112 in between. The fuel electrode side frame 140 collects gas that has passed through the cell side gas passages (fuel chamber 176, fuel electrode side supply communication passage 142, and fuel electrode side discharge communication passage 143) facing the fuel electrode 116 of each single cell 110. has a first surface 41 defining an anode-side exhaust manifold 172 through which the fuel flows. The interconnector 190 contains a target element that is at least one of Mn and Fe, and has a surface that defines an upstream gas flow path (fuel chamber 176) located upstream with respect to the fuel electrode side exhaust manifold 172. . A specific compound 43 containing a specific element that forms a compound with the target element is present on the first surface 41 of the fuel electrode frame 140 that defines the fuel electrode exhaust manifold 172 .

As described above, in this embodiment, the fuel electrode side frame has the first surface 41 that defines the fuel electrode side exhaust manifold 172 through which the gas that has passed through the cell side gas flow path facing the fuel electrode 116 of each single cell 110 flows. On the first surface 41 at 140, there is a specific compound 43 containing a specific element that forms a compound with the target element, which is at least one of Mn and Fe. Therefore, even if target elements contained in the interconnector 190 are scattered into the upstream gas flow path (fuel chamber 176) when the fuel cell module 10 is heated to a high temperature during operation, etc., In the fuel electrode side exhaust manifold 172 located on the downstream side, the target element can be captured by the specific element contained in the specific compound. Therefore, in a downstream device (for example, the combustor 333) to which the gas discharged from the fuel electrode side exhaust manifold 172 is supplied, problems caused by the target element being contained in the gas (for example, the combustion nozzle in the combustor 333 clogging) can be suppressed.

Further, in this embodiment, the fuel electrode side frame 140 having the first surface 41 has a metal portion 140a and a coat layer 140b that covers the surface of the metal portion 140a. Specific compounds 43 are discretely formed on the surface. Therefore, it is possible to disperse the stress caused by volumetric expansion and contraction during the reaction in which the target element is captured by the specific element contained in the specific compound 43, and as a result, the occurrence of cracks in the coating layer 140b can be suppressed. Can be done.

Further, in this embodiment, the metal portion 140a of the fuel electrode side frame 140 contains a specific element. Therefore, in the fuel electrode side frame 140, the specific element can be continuously supplied from the metal part 140a to the surface of the coat layer 140b, and the function of capturing the target element by the specific compound 43 present on the surface of the coat layer 140b continues. can be maintained.

Further, in this embodiment, the content ratio of the specific element on the surface of the coating layer 140b of the fuel electrode side frame 140 is larger than the content ratio of the specific element in the metal portion 140a. Therefore, the target element can be effectively captured by the specific element on the surface of the coating layer 140b.

Further, in this embodiment, the fuel electrode side frame 140 has a second surface 42 that defines a fuel electrode side supply manifold 171 that supplies gas to the cell side gas flow path of each unit cell 110. There is also a specific compound 43. Therefore, the target element in the fuel gas FG supplied to the cell side gas flow path of each unit cell 110 through the fuel electrode side supply manifold 171 can be captured by the specific compound 43 present on the second surface 42. It is possible to suppress the occurrence of defects (for example, cracks in the electrolyte layer 112, etc.) caused by the scattering of the target element into the cell-side gas flow path.

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 gist of the invention. For example, the following modifications are also possible.

The configurations of the fuel cell module 10 and its constituent members in the above embodiment are merely examples, and can be modified in various ways. For example, in the above embodiment, the specific compound 43 is formed discretely on the surface of the fuel electrode side frame 140 that defines the manifold, but the specific compound 43 may be continuously formed on the surface.

In the above embodiment, the fuel electrode side frame 140 has the metal part 140a and the coat layer 140b, but the fuel electrode side frame 140 may not have the coat layer 140b. Further, in the above embodiment, the coat layer 140b of the fuel electrode side frame 140 includes the inner layer 140c and the outer layer 140d, but the coat layer 140b may have a single layer structure or a structure of three or more layers. You can. Further, in the above embodiment, the metal portion 140a contains the specific element, but the metal portion 140a may not contain the specific element. Further, in the embodiment described above, the content ratio of the specific element on the surface of the coat layer 140b is higher than the content ratio of the specific element on the metal part 140a, but such a magnitude relationship is not necessarily required.

In the embodiment described above, the specific compound 43 is present on the surface of the fuel electrode side frame 140 that defines the manifold, but instead of or in addition to this, other manifold defining members (for example, the lower end plate 106 , the lower end separator 189, the single cell separator 120, the interconnector separator 180, etc.), the specific compound 43 may be present on the surface defining the manifold.

The specific compound 43 is present on the surface of the manifold defining member that defines the fuel electrode side exhaust manifold 172, but the specific compound 43 is present on the surface of the manifold defining member or other manifold defining member that defines the fuel electrode side supply manifold 171. It may not exist. Conversely, the specific compound 43 is present on the surface of the manifold defining member that defines the fuel electrode side supply manifold 171, but the specific compound 43 is present on the surface of the manifold defining member or other manifold defining member that defines the fuel electrode side exhaust manifold 172. Compound 43 may not exist.

In the above embodiment, the specific compound 43 is present on the surface of the exhaust manifold and/or supply manifold on the fuel electrode side, but instead of or in addition to this, the specific compound 43 is present on the exhaust manifold and/or supply manifold on the air electrode side. The specific compound 43 may be present on the surface. The electrode (fuel electrode 116 and/or air electrode 114) corresponding to the manifold where the specific compound 43 is present is an example of the specific electrode in the claims.

In the above embodiment, the interconnector 190 as a flow path defining member contains the target element (Mn and/or Fe), but instead of or in addition to this, other flow path defining members (for example, Lower end plate 106, lower end separator 189, single cell separator 120, interconnector separator 180, gas passage member 27, air electrode side gas supply channel 61 connected to fuel cell stack 100, and fuel electrode side gas supply Various types of piping forming the flow path 71) may contain the target element. Further, the material for forming the flow path defining member may be metal, ceramics, or other materials.

In the above embodiment, the target is a SOFC that generates power using an electrochemical reaction between hydrogen contained in fuel gas and oxygen contained in oxidant gas, but the technology disclosed herein is The same applies to electrolytic single cells, which are the constituent units of solid oxide electrolytic cells (SOEC) that generate hydrogen using electrolysis reactions, and electrolytic cell modules including electrolytic cell stacks that include multiple electrolytic single cells. It is possible. Note that the configuration of the electrolytic cell is known, for example, as described in JP-A-2016-81813, so it will not be described in detail here, but it is generally the same configuration as the fuel cell in the embodiment described above. . That is, if the fuel cell module 10 in the embodiment described above is read as an electrolytic cell module, the fuel cell stack 100 is read as an electrolytic cell stack, the power generation unit 102 is read as an electrolytic cell unit, and the single cell 110 is read as an electrolytic single cell. good. However, during operation of the electrolytic cell module, a voltage is applied between the two electrodes such that the air electrode 114 is positive (anode) and the fuel electrode 116 is negative (cathode), and the raw material gas is passed through the manifold. water vapor is supplied. As a result, an electrolysis reaction of water occurs in each electrolytic cell unit, hydrogen gas is generated in the fuel chamber 176, and hydrogen is taken out to the outside of the electrolytic cell stack via the manifold. Even in an electrolytic cell module having such a configuration, if a configuration similar to that of the above embodiment is adopted, problems caused by target elements being contained in the gas discharged from the manifold will be avoided in the downstream device to which the gas discharged from the manifold is supplied. The occurrence can be suppressed.

In the above embodiment, the so-called flat plate type fuel cell stack was explained as an example, but the technology disclosed in this specification is not limited to the flat plate type, but can also be applied to other types (so-called cylindrical flat plate type or cylindrical type). It is equally applicable to fuel cells (or electrolytic cells).

10: Fuel cell module 22: Bolt 24: Nut 26: Insulating sheet 27: Gas passage member 28: Main body 29: Branch 32, 34: Hole 41: First surface 42: Second surface 43: Specific compound 61: Air Pole side gas supply channel 71: Fuel electrode side gas supply channel 100: Fuel cell stack 102: Power generation unit 103: Power generation block 104: Upper end plate 106: Lower end plate 108: Communication hole 109: Bolt hole 110: Single Cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 118: Intermediate layer 120: Single cell separator 121: Through hole 124: Joint portion 125: Glass seal portion 126: Inside portion 127: Outside portion 128: Connection portion 130: Air electrode side frame 131: Hole 132: Air electrode side supply communication channel 133: Air electrode side discharge communication channel 134: Air electrode side current collector 140: Fuel electrode side frame 140a: Metal part 140b: Coat layer 140c: Inner layer 140d: Outer layer 141: Hole 142: Fuel electrode side supply communication channel 143: Fuel electrode side discharge communication channel 144: Fuel electrode side current collector section 145: Electrode opposing section 146: Interconnector opposing section 149: Spacer 150: Flat plate section 161: Air electrode side supply manifold 162: Air electrode side exhaust manifold 166: Air chamber 171: Fuel electrode side supply manifold 172: Fuel electrode side exhaust manifold 176: Fuel chamber 180: Interconnector separator 181: Through hole 186: Inside part 187: Outside part 188: Connecting part 189: Lower end separator 190: Interconnector 194: Covering layer 196: Conductive bonding material 198: Oxide film 226: Exhaust gas relay flow path 228: Mixed gas flow path 230: Fuel electrode side gas discharge Channel 240: Air electrode side gas discharge channel 251: Pure water introduction channel 261: Raw fuel gas introduction channel 271: Air introduction channel 300: Auxiliary device 310: Evaporator 330: Reformer/heater 331: Reformer Heater 333: Combustor 335: Housing 336: Inner wall 337: Outer wall 338: Air flow path 339: Heat transfer fin 350: Heat insulating material 351: Heat insulating space

Claims (5)

A plurality of electrochemical reaction single cells arranged in a predetermined direction, each including an electrolyte layer made of a solid oxide, and an air electrode and a fuel electrode facing each other with the electrolyte layer in between;
at least one manifold defining member, the exhaust manifold through which gas passes through each cell-side gas flow path facing a specific electrode that is one of the air electrode and the fuel electrode of each electrochemical reaction unit cell; at least one manifold-defining member including a manifold-defining member having a defining first surface;
a flow path defining member containing a target element that is at least one of Mn and Fe and having a surface that defines an upstream gas flow path located upstream with respect to the discharge manifold;
In an electrochemical reaction module comprising:
A specific compound containing a specific element that forms a compound with the target element is present on the first surface of the manifold defining member;
An electrochemical reaction module characterized by: The electrochemical reaction module according to claim 1,
The manifold defining member having the first surface includes:
metal part and
a coating layer covering the surface of the metal part;
has
The specific compound is discretely formed on the surface of the coat layer, which is the first surface.
An electrochemical reaction module characterized by: The electrochemical reaction module according to claim 2,
The metal part contains the specific element,
An electrochemical reaction module characterized by: The electrochemical reaction module according to claim 2 or 3,
The content ratio of the specific element on the surface of the coating layer is higher than the content ratio of the specific element in the metal part,
An electrochemical reaction module characterized by: The electrochemical reaction module according to any one of claims 1 to 3,
the at least one manifold-defining member includes a manifold-defining member having a second surface defining a supply manifold for supplying gas to the cell-side gas flow path of each electrochemical reaction unit cell;
the specific compound is present on the second surface of the manifold defining member;
An electrochemical reaction module characterized by:

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