Electrochemical reaction cell stack
The innovative sealing member configuration with glass seals and insulating ceramics in electrochemical reaction cell stacks addresses the issue of poor bonding and cracks, ensuring stack integrity and reducing leakage current without increasing size.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MORIMURA SOFC TECH CO LTD
- Filing Date
- 2024-05-20
- Publication Date
- 2026-06-08
AI Technical Summary
The challenge in electrochemical reaction cell stacks, such as solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs), is the occurrence of poor bonding and cracks in the sealing members without increasing the stack size.
The proposed solution involves a sealing member configuration comprising a first and second glass seal with an insulating ceramics intermediate seal, where a conductive member is placed between virtual surfaces, and insulating members are used to prevent contact and leakage current, allowing for a secure space without increasing the stack size.
This configuration reduces the occurrence of joining defects and cracks in the sealing member, suppresses leakage current, and prevents delamination, maintaining the integrity of the stack.
Smart Images
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Abstract
Description
Technical Field
[0006] , ,
[0005] ,
[0001] The technology disclosed in this specification relates to an electrochemical reaction cell stack.
Background Art
[0002] As one type of fuel cell that generates electricity by utilizing the electrochemical reaction between hydrogen and oxygen, a solid oxide fuel cell (hereinafter referred to as "SOFC") having an electrolyte layer containing a solid oxide is known. SOFCs are generally used in the form of a fuel cell stack in which a plurality of constituent units (electrochemical reaction units) are arranged side by side in a predetermined direction.
[0003] In order to seal between two members provided in a fuel cell stack, a sealing member is used. As the sealing member, a member including first and second glass frit layers and an insulating layer disposed between the first and second frit layers may be used (see Patent Document 1).
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In the above SOFC, without increasing the size of the stack, it is required to reduce the occurrence of poor bonding and cracks in the sealing member.
[0006] Such a problem is also a common problem in an electrolysis cell stack including a plurality of electrolysis cell units, which are constituent units of a solid oxide electrolysis cell (hereinafter referred to as "SOEC") that generates hydrogen by utilizing the electrolysis reaction of water. Further, such a problem is not limited to SOFCs and SOECs, but is a common problem in other types of electrochemical reaction cell stacks. [Means for solving the problem]
[0007] The technologies disclosed herein can be implemented, for example, in the following forms: (1) An electrochemical reaction cell stack disclosed herein comprises a first member to be joined, a second member to be joined, and a sealing member that joins the first member to be joined and the second member to be joined, wherein the sealing member comprises a first glass seal made of glass that is joined to the first member to be joined, a second glass seal made of glass that is joined to the second member to be joined, and an intermediate seal made of insulating ceramics disposed between the first glass seal and the second glass seal, wherein a conductive member electrically connected to the second member to be joined, or a part of the second member to be joined, is disposed between a first virtual surface including the joining surface of the first member to be joined and the first glass seal, and a second virtual surface including the joining surface of the second member to be joined and the second glass seal.
[0008] With the above configuration, a large space for placing the sealing member between the first and second members to be joined can be secured without increasing the size of the stack. This reduces the occurrence of joining defects and cracks in the sealing member.
[0009] (2) In the electrochemical reaction cell stack described in (1) above, the conductive member is disposed between the first virtual surface and the second virtual surface, the conductive member has a conductive seal hole, and at least a part of the seal member is disposed inside the conductive seal hole.
[0010] With this configuration, a space for placing a sealing member can be easily secured between the first member to be joined and the second member to be joined.
[0011] (3) In the electrochemical reaction cell stack described in (2) above, there may be a gap between the conductive member and the intermediate seal.
[0012] With this configuration, since the conductive member and the intermediate seal are not in contact, leakage current flowing through the intermediate seal to the first or second glass seal is suppressed. This reduces the occurrence of delamination of the seal member from the second end plate.
[0013] (4) The electrochemical reaction cell stack described in (2) or (3) above further comprises an insulating member disposed between the conductive member and the first member to be joined, wherein the insulating member has an insulating seal hole, a part of the seal member is disposed inside the insulating seal hole, and the distance between the intermediate seal and the insulating member may be smaller than the distance between the intermediate seal and the conductive member.
[0014] With this configuration, contact between the conductive member and the intermediate seal is prevented by the insulating member, thus suppressing the flow of leakage current from the intermediate seal to the first or second glass seal. This reduces the occurrence of delamination from the second end plate of the seal member.
[0015] (5) In the electrochemical reaction cell stack described in (1) above, the second member to be joined has an opposing surface facing the first member to be joined and a recess disposed on the opposing surface, and at least a part of the sealing member may be disposed inside the recess.
[0016] With this configuration, a space for placing a sealing member can be easily secured between the first member to be joined and the second member to be joined.
[0017] (6) In the electrochemical reaction cell stack described in (5) above, there may be a gap between the second member to be joined and the intermediate seal.
[0018] According to such a configuration, since the second joining target member and the intermediate seal are not in contact with each other, leakage current flowing through the intermediate seal to the first glass seal or the second glass seal is suppressed. As a result, the occurrence of peeling of the seal member from the second end plate is reduced.
[0019] (7) The electrochemical reaction cell stack according to the above (5) or (6) further includes an insulating member disposed between the first joining target member and the second joining target member, the insulating member has an insulating seal hole, a part of the seal member is disposed inside the insulating seal hole, and the distance between the intermediate seal and the insulating member may be smaller than the distance between the intermediate seal and the second joining target member.
[0020] According to such a configuration, since the contact between the second joining target member and the intermediate seal is blocked by the insulating member, leakage current flowing through the intermediate seal to the first glass seal or the second glass seal is suppressed. As a result, the occurrence of peeling of the seal member from the second end plate is reduced.
[0021] The technology disclosed in this specification can be realized in various forms. For example, it can be realized in the form of an electrochemical reaction cell stack and its manufacturing method.
Brief Description of Drawings
[0022] [Figure 1] Perspective view showing the external configuration of the fuel cell stack of the embodiment [Figure 2] Cross-sectional view showing the fuel cell stack of the embodiment cut along the line II-II in FIG. 1 [Figure 3] Cross-sectional view showing the fuel cell stack of the embodiment cut along the line III-III in FIG. 1 [Figure 4] Cross-sectional view showing two adjacent electrochemical reaction units in the fuel cell stack of the embodiment cut at the same position as the line II-II in FIG. 1 [Figure 5]Cross-sectional view showing two adjacent electrochemical reaction units in the fuel cell stack of the embodiment, cut at the same position as the line III-III in FIG. 1 [Figure 6] Partial enlarged cross-sectional view showing the inside of the frame F1 in FIG. 2 enlarged [Figure 7] Partial enlarged cross-sectional view showing the inside of the frame F2 in FIG. 6 enlarged [Figure 8] Cross-sectional view showing the fuel cell stack of the embodiment cut along the line VIII-VIII in FIG. 6 [Figure 9] Partial enlarged cross-sectional view of the fuel cell stack of the modified example
Mode for Carrying Out the Invention
[0023] A. First Embodiment: The first embodiment will be described with reference to FIGS. 1 to 8. The fuel cell stack 10 (an example of an electrochemical reaction cell stack) of the present embodiment is used in a solid oxide type fuel cell including an electrolyte layer 112 containing a solid oxide.
[0024] (Overall Configuration of Fuel Cell Stack 10) As shown in FIGS. 1 to 3, the fuel cell stack 10 includes a power generation block 100, a terminal separator 230, a first plate 232, a second plate 260 (an example of an insulating member), a third plate 610, a base plate 600 (an example of a conductive member), a first terminal plate 240, a second terminal plate 250, an insulating portion 220, a first end plate 210, a second end plate 270 (an example of a first joining target member), and four gas passage members 280. The first end plate 210, the insulating portion 220, the terminal separator 230, the first terminal plate 240, the power generation block 100, the second terminal plate 250, the third plate 610, the base plate 600, the second plate 260, and the second end plate 270 have substantially the same rectangular outer shape and are arranged to overlap in this order in a predetermined arrangement direction (the vertical direction in FIG. 2).
[0025] As shown in Figure 1, the fuel cell stack 10 has bolt holes BH near each of its four corners, each extending from the first end plate 210 to the second end plate 270. A bolt B is inserted into each bolt hole BH. Nuts N are threaded onto both ends of each bolt B. These bolts B and nuts N fasten the components from the first end plate 210 to the second end plate 270 together. As shown in Figures 2 and 3, the first plate 232 is supported by the end separator 230, and the four gas passage members 280 are connected to the second end plate 270.
[0026] As shown in Figures 2 and 3, the power generation block 100 is composed of a plurality (seven in this embodiment) of electrochemical reaction units 100U (hereinafter sometimes abbreviated as "reaction unit 100U") arranged in a predetermined arrangement direction (up and down direction in Figure 2).
[0027] (Overall composition of an electrochemical reaction unit of 100U) As shown in Figures 4 and 5, the electrochemical reaction unit 100U comprises a single cell 110, a single cell separator 120, an air electrode frame 130, a fuel electrode frame 140, a fuel electrode current collector 144, two interconnectors 190, and two IC separators 180. One IC separator 180, the air electrode frame 130, the single cell separator 120, the fuel electrode frame 140, and the other IC separator 180 are arranged in this order. The single cell 110 is supported by the single cell separator 120, the two interconnectors 190 are each supported by the two IC separators 180, and the fuel electrode current collector 144 is positioned between the single cell 110 and the interconnectors 190. The IC separators 180 and interconnectors 190 are shared by two adjacent reaction units 100U. In the following description, when a reaction unit 100U located at one end of the multiple reaction units 100U that is closest to the second end plate 270 (the lower end in Figure 2) is described separately from the others, it will be referred to as "reaction unit 100UN". Furthermore, when an IC separator 180 provided in this reaction unit 100UN and located on the outermost layer of the power generation block 100 is described separately from the others, it will be referred to as "IC separator 180E". IC separator 180E is an example of a second joining target member.
[0028] (Single cell 110) The single cell 110 comprises an electrolyte layer 112, an air electrode 114, and a fuel electrode 116. As shown in Figures 4 and 5, the air electrode 114, the electrolyte layer 112, and the fuel electrode 116 are arranged in this order, with a reaction prevention layer 118 interposed between the electrolyte layer 112 and the air electrode 114. The single cell 110 of this embodiment is a fuel electrode-supported single cell in which the other layers constituting the single cell 110 (electrolyte layer 112, air electrode 114, and reaction prevention layer 118) are supported by the fuel electrode 116.
[0029] The electrolyte layer 112 is a rectangular, flat member having one surface on which the air electrode 114 is located (the upper surface in Figures 4 and 5) and another surface parallel to the air electrode 116 (the lower surface in Figures 4 and 5). The electrolyte layer 112 is a layer containing a solid oxide (e.g., YSZ (yttria-stabilized zirconia)). The air electrode 114 is a layer having a rectangular shape smaller than the electrolyte layer 112 and contains, for example, a perovskite-type oxide (e.g., LSCF (lanthanum strontium cobalt iron oxide)). The fuel electrode 116 is a layer having a rectangular shape approximately the same size as the electrolyte layer 112 and contains, for example, Ni (nickel), a cermet made of Ni and ceramic particles, a Ni-based alloy, etc. The reaction prevention layer 118 is a layer having a rectangular shape approximately the same size as the air electrode 114 and contains, for example, GDC (gadolinium-doped ceria). The reaction prevention layer 118 has the function of suppressing the reaction of elements (e.g., Sr) diffused from the air electrode 114 with elements (e.g., Zr) contained in the electrolyte layer 112 to produce a highly resistive substance (e.g., SrZrO3).
[0030] (Single-cell separator 120) As shown in Figures 4 and 5, the single-cell separator 120 is a rectangular frame-shaped member having a roughly rectangular through-hole 121 near its center. The single-cell separator 120 is conductive and made of a metal such as ferritic stainless steel. The thickness of the single-cell separator 120 is, for example, 0.05 mm or more and 0.2 mm or less. The periphery of the through-hole 121 in the single-cell separator 120 is joined to the periphery of one surface of the electrolyte layer 112 (the surface on which the air electrode 114 is placed: the upper surface in Figures 4 and 5) by a joint 124. The joint 124 is made of, for example, brazing material (Ag brazing).
[0031] (Air pole frame 130) As shown in Figures 4 and 5, the air electrode frame 130 is a rectangular frame-shaped member having a roughly rectangular through-hole 131 near the center, and is formed of, for example, an insulating ceramic (such as mica). The thickness of the air electrode frame 130 is, for example, 0.5 mm or more and 5 mm or less.
[0032] (Fuel pole frame 140) As shown in Figure 5, the fuel electrode frame 140 is a rectangular frame-shaped member having a roughly rectangular through-hole 141 near its center. The fuel electrode frame 140 is conductive and is made of a metal such as ferritic stainless steel.
[0033] (IC separator 180) As shown in Figures 4 and 5, the IC separator 180 is a rectangular frame-shaped member having a through hole 181 near the center. The IC separator 180 is conductive and is made of a metal such as ferritic stainless steel. The thickness of the IC separator 180 is, for example, 0.05 mm or more and 0.2 mm or less.
[0034] (Interconnector 190, and fuel electrode current collector 144) As shown in Figures 4 and 5, the interconnector 190 comprises a rectangular flat plate portion 191, a plurality of plate-shaped air electrode current collector portions 192 protruding from one surface of the flat plate portion 191 toward the air electrode 114, and a coating layer 193. The flat plate portion 191 and the air electrode current collector portions 192 are conductive and are made of a metal such as ferritic stainless steel. The coating layer 193 is conductive and is made of a spinel-type oxide, for example. The coating layer 193 is arranged to cover the surface of the air electrode current collector portions 192 and the surface of the flat plate portion 191 on which the air electrode current collector portions 192 are arranged. The flat plate portion 191 is joined to the periphery of the through hole 181 in the IC separator 180, for example, by welding.
[0035] The fuel electrode current collector 144 is a member that connects the interconnector 190 and the fuel electrode 116, and is formed of a conductive material such as nickel, a nickel alloy, or stainless steel. As shown in Figures 4 and 5, the fuel electrode current collector 144 comprises an interconnector-facing portion 146, an electrode-facing portion 145 parallel to the interconnector-facing portion 146, and a connecting portion 147 connecting the electrode-facing portion 145 and the interconnector-facing portion 146, and is U-shaped overall. The electrode-facing portion 145 is in contact with the fuel electrode 116, and the interconnector-facing portion 146 is in contact with the flat plate portion 191 of the interconnector 190.
[0036] As described above, the interconnector 190 is shared by two adjacent reaction units 100U. More specifically, as shown in Figures 4 and 5, the air electrode current collector 192 is joined to the air electrode 114 of a single cell 110 provided in one of the two adjacent reaction units 100U via a conductive bonding material 196 made of, for example, a spinel-type oxide, thereby electrically connecting to the air electrode 114. The flat plate portion 191 is electrically connected to the fuel electrode 116 of a single cell 110 provided in the other of the two adjacent reaction units 100U via a fuel electrode current collector 144. This ensures electrical conductivity between the two adjacent reaction units 100U.
[0037] A spacer 149, for example made of mica, is placed between the electrode facing portion 145 and the interconnect facing portion 146. As a result, the fuel electrode current collector 144 follows the deformation of the reaction unit 100U due to temperature cycles and reaction gas pressure fluctuations, and the electrical connection between the fuel electrode 116 and the interconnect 190 (or second terminal plate 250) via the fuel electrode current collector 144 is maintained well.
[0038] (Air chamber 313 and fuel chamber 323) As shown in Figures 4 and 5, the space partitioned by the single-cell separator 120 and single cell 110, the air electrode frame 130, the IC separator 180 and interconnector 190 faces the air electrode 114 and forms an air chamber 313 through which the oxidizer gas OG flows. The air electrode frame 130 partitions the air chamber 313 from the outside space around its entire circumference and seals the space between the single-cell separator 120 and the IC separator 180, preventing gas from leaking from the air chamber 313 into the outside space.
[0039] Furthermore, the space partitioned by the single-cell separator 120 and single cell 110, the fuel electrode frame 140, the IC separator 180 and interconnector 190 faces the fuel electrode 116 and forms a fuel chamber 323 through which fuel gas FG flows. The fuel electrode frame 140 partitions the fuel chamber 323 from the outside space around its entire circumference and seals the space between the single-cell separator 120 and the IC separator 180, preventing gas from leaking from the fuel chamber 323 into the outside space.
[0040] The single-cell separator 120 separates the air chamber 313 from the fuel chamber 323, suppressing gas leakage (cross-leakage) from the air electrode 114 to the fuel electrode 116, or from the fuel electrode 116 to the air electrode 114, around the single-cell 110. In addition, the IC separator 180 and interconnector 190 suppress gas leakage between adjacent reaction units 100U.
[0041] (First end plate 210) The first end plate 210 is a member formed by press-forming (bending) a single plate-shaped member. The first end plate 210 is made of a metal such as ferritic stainless steel. The thickness of the first end plate 210 is, for example, 0.5 mm or more and 3 mm or less. As shown in Figures 1-3, the first end plate 210 comprises a rectangular frame-shaped planar portion 211 having a through hole 212 near the center, and an outer projection 213 and an inner projection 214 that protrude from the planar portion 211 in the opposite direction to the insulating portion 220 (upwards in Figure 2). The planar portion 211 has holes that constitute the bolt holes BH described above. The outer projection 213 protrudes from the outer peripheral edge of the planar portion 211. The outer projection 213 is arranged around the entire circumference of the outer peripheral portion of the planar portion 211. The inner projection 214 protrudes from the inner peripheral edge of the planar portion 211. The inner protrusion 214 is arranged around the entire circumference of the inner part of the flat part 211.
[0042] (Insulation part 220) The insulating portion 220 is a rectangular frame-shaped member with a through hole near the center, and is made of an insulating material. As shown in Figures 2 and 3, the insulating portion 220 is sandwiched between the first end plate 210 and the end separator 230, thereby ensuring insulation between the first end plate 210 and the end separator 230.
[0043] (End separator 230) As shown in Figures 2 and 3, the end separator 230 is a rectangular frame-shaped member having a through hole 231 near its center. The end separator 230 is conductive and is made of a metal such as ferritic stainless steel.
[0044] (Plate 1, No. 232) The first plate 232 is a rectangular, flat member. The first plate 232 is conductive and is made of a metal such as ferritic stainless steel. As shown in Figures 2 and 3, the first plate 232 is joined to the peripheral portion of the through hole 231 in the end separator 230, for example, by welding. The end separator 230 and the first plate 232 separate the power generation block 100 from the external space of the fuel cell stack 10.
[0045] The first plate 232 is connected to an interconnector 190 provided on a reaction unit 100U located at the other end (upper end in Figure 2) of the multiple reaction units 100U that constitute the power generation block 100, via a connecting member with the same structure as the fuel electrode current collector 144. In this way, the reaction unit 100U and the first plate 232 are electrically connected.
[0046] (Terminal 1 Plate 240) As shown in Figures 2 and 3, the first terminal plate 240 is a rectangular frame-shaped member having a through hole 241 near its center. The first terminal plate 240 is conductive and made of a metal such as ferritic stainless steel. The thickness of the first terminal plate 240 is, for example, 0.2 mm or more and 3 mm or less. The first terminal plate 240 is electrically connected to the reaction unit 100U located at the other end (upper end in Figure 2) of the multiple reaction units 100U that constitute the power generation block 100, via the first plate 232 and the end separator 230. One end of the first terminal plate 240 (right end in Figure 2) protrudes laterally from the power generation block 100, and this protruding portion functions as the positive output terminal of the fuel cell stack 10.
[0047] (Terminal 2 Plate 250) As shown in Figures 2 and 3, the second terminal plate 250 is a rectangular frame-shaped member having a through hole 251 near its center. The second terminal plate 250 is conductive and made of a metal such as ferritic stainless steel. The thickness of the second terminal plate 250 is, for example, 0.2 mm or more and 3 mm or less. The second terminal plate 250 is positioned between the single-cell separator 120 and the IC separator 180E provided in the reaction unit 100UN, and is electrically connected to the single cell 110 via the single-cell separator 120. One end of the second terminal plate 250 (the right end in Figure 2) protrudes laterally from the power generation block 100, and this protruding portion functions as the negative output terminal of the fuel cell stack 10.
[0048] (Plate 3, page 610) As shown in Figures 2 and 3, the third plate 610 is a rectangular frame-shaped member having a through hole 611 near the center. The third plate 610 is formed of an insulating material such as mica.
[0049] (Base plate 600) The base plate 600 is a rectangular, flat component. The base plate 600 is conductive and is made of a metal such as ferritic stainless steel. The base plate 600 is in contact with an interconnector 190 supported by an IC separator 180E, and is electrically connected to the reaction unit 100UN via this interconnector 190.
[0050] (Plate 2, page 260) The second plate 260 is a rectangular, flat member, formed from an insulating material such as mica.
[0051] (Second end plate 270) The second end plate 270 is a component formed by press-forming (bending) a single plate-shaped member. The second end plate 270 is made of a metal such as ferritic stainless steel. The thickness of the second end plate 270 is, for example, 0.5 mm or more and 3 mm or less. As shown in Figures 2 and 3, the second end plate 270 comprises a rectangular frame-shaped planar portion 271 having a through hole 272 near the center, and an outer projection 273 and an inner projection 274 projecting from the planar portion 271 in the opposite direction from the second terminal plate 250 (downward in Figure 2). The outer projection 273 protrudes from the outer peripheral edge of the planar portion 271. The outer projection 273 is arranged around the entire circumference of the outer peripheral portion of the planar portion 271. The inner projection 274 protrudes from the inner peripheral edge of the planar portion 271. The inner projection 274 is arranged around the entire circumference of the inner peripheral portion of the planar portion 271.
[0052] As shown in Figures 2 and 3, the peripheral edge of the second plate 260 is sandwiched between the second end plate 270 and the base plate 600, thereby ensuring insulation between the base plate 600 and the second end plate 270.
[0053] (Manifolds 311, 312, 321, 322) As shown in Figures 1-3, the fuel cell stack 10 has four holes that penetrate from the power generation block 100 to the second end plate 270. The four holes are the oxidizer gas supply manifold 311, the oxidizer gas discharge manifold 312, the fuel gas supply manifold 321, and the fuel gas discharge manifold 322, respectively.
[0054] As shown in Figure 2, the oxidizer gas supply manifold 311 is a gas flow path that supplies oxidizer gas OG, introduced from outside the fuel cell stack 10, to the air chamber 313 of each reaction unit 100U. The oxidizer gas discharge manifold 312 is a gas flow path that discharges oxidizer off-gas OOG, discharged from the air chamber 313 of each reaction unit 100U, to the outside of the fuel cell stack 10. For example, air is used as the oxidizer gas OG.
[0055] As shown in Figure 3, the fuel gas supply manifold 321 is a gas passage that supplies fuel gas FG introduced from outside the fuel cell stack 10 to the fuel chamber 323 of each reaction unit 100U. The fuel gas discharge manifold 322 is a gas passage that discharges fuel off-gas FOG discharged from the fuel chamber 323 of each reaction unit 100U to the outside of the fuel cell stack 10. As the fuel gas FG, for example, hydrogen-rich gas obtained by reforming city gas is used.
[0056] The IC separator 180E has four manifold holes. The four manifold holes are holes that penetrate the second terminal plate 250 and are parts of manifolds 311, 312, 321, and 322, respectively. Hereinafter, of the four manifold holes provided in the IC separator 180E, the manifold hole that forms part of the oxidizer gas supply manifold 311 will be referred to as "manifold hole 311H1" (see Figure 6).
[0057] The second end plate 270 has four manifold holes. Each of the four manifold holes is a hole that penetrates the second end plate 270 and is part of the four manifolds 311, 312, 321, and 322. Hereinafter, of the four manifold holes provided in the second end plate 270, the manifold hole that forms part of the oxidizer gas supply manifold 311 will be referred to as "manifold hole 311H2" (see Figure 6).
[0058] (Gas passage member 280) Each of the four gas passage members 280 comprises a main body portion 281 and a flange portion 282, as shown in Figures 1-3. The main body portion 281 is cylindrical with open ends. The flange portion 282 is provided so as to protrude outward from one end of the main body portion 281 (the lower end in Figure 2). The flange portion 282 has a plurality of bolt holes 284. Bolts (not shown) for connecting the fuel cell stack 10 to an external device are inserted into each bolt hole 284.
[0059] The second end plate 270 is provided with four retaining cylindrical portions 275 for connecting the gas passage member 280. As shown in Figure 6, one of the four retaining cylindrical portions 275 is a cylindrical portion extending from the edge of the manifold hole 311H2 toward the opposite side of the power generation block 100 (downward in Figure 6). One end of the main body portion 281 (upper end in Figure 6) is joined to the retaining cylindrical portion 275, for example, by welding. The internal space of the main body portion 281 is in communication with the oxidizer gas supply manifold 311. Gas piping (not shown) for gas supply or discharge is connected to each main body portion 281. The other three retaining cylindrical portions 275 are positioned corresponding to manifolds 312, 321, and 322, respectively, and are similarly connected to the gas passage member 280.
[0060] (Joining structure between IC separator 180E and second end plate 270) The second end plate 270 is joined to the IC separator 180E via a sealing member 500. More specifically, the peripheral portions of the four manifolds 311, 312, 321, and 322 in the planar portion 271 are each joined to the IC separator 180E via the sealing member 500. Since the periphery joining structures of the four manifolds 311, 312, 321, and 322 are identical, the periphery joining structure of the oxidizer gas supply manifold 311 will be described below, and the other three will not be described.
[0061] As described above, the third plate 610, the base plate 600, and the second plate 260 are arranged in this order between the IC separator 180E and the second end plate 270.
[0062] As shown in Figure 6, the second plate 260 has a second seal hole 261 (an example of an insulating seal hole) at a position corresponding to the oxidizer gas supply manifold 311. The second seal hole 261 is slightly larger than the manifold holes 311H1 and 311H2 and penetrates the second plate 260. The third plate 610 has a third seal hole 612 at a position corresponding to the oxidizer gas supply manifold 311. The third seal hole 612 is approximately the same size as the second seal hole 261 and penetrates the third plate 610. The base plate 600 has a first seal hole 601 (an example of a conductive seal hole) at a position corresponding to the oxidizer gas supply manifold 311. The first seal hole 601 is slightly larger than the second seal hole 261 and the third seal hole 612 and penetrates the base plate 600. The first seal hole 601, the second seal hole 261, and the third seal hole 612 are arranged concentrically, and the seal member 500 is housed inside them.
[0063] As shown in Figure 7, the sealing member 500 comprises a first glass seal 510, a second glass seal 520, and an intermediate seal 530, which are arranged in that order.
[0064] The first glass seal 510 is an annular member having a first through hole 511, as shown in Figure 6-8. The first glass seal 510 is made of glass. The first glass seal 510 may be made of, for example, SiO2-B2O3-MgO glass. As shown in Figures 6 and 7, one side of the first glass seal 510 is bonded to the second end plate 270 and the other side is bonded to the intermediate seal 530.
[0065] The second glass seal 520 is an annular member having a second through hole 521 and has substantially the same shape as the first glass seal 510. The second glass seal 520 is made of glass. The second glass seal 520 may be made of, for example, SiO2-B2O3-MgO glass. As shown in Figures 6 and 7, one side of the second glass seal 520 is bonded to the IC separator 180E and the other side is bonded to the intermediate seal 530.
[0066] As shown in Figure 6-8, the intermediate seal 530 is an annular member having a third through-hole 531. The intermediate seal 530 is an insulating member. The material of the intermediate seal 530 may be any material with a higher electrical resistivity than the glass used in the first glass seal 510 and the second glass seal 520, for example, an insulating ceramic. More specifically, the intermediate seal 530 may be a ceramic containing magnesium oxide (MgO), or a ceramic mainly composed of magnesium oxide. In this specification, "main component" means that the component is present in an amount of 90 volume or more. In this embodiment, the intermediate seal 530 contains 90 volume or more of magnesium oxide, and also contains sintering aids (e.g., CaO, SiO2, Al2O3), etc. The external shape of the intermediate seal 530 is slightly larger than that of the first glass seal 510 and the second glass seal 520, and the third through-hole 531 is slightly smaller than that of the first through-hole 511 and the second through-hole 512.
[0067] As shown in Figures 6 and 7, the intermediate seal 530 is sandwiched between the first glass seal 510 and the second glass seal 520. The first glass seal 510, the second glass seal 520, and the intermediate seal 530 are concentrically arranged such that the first through hole 511, the second through hole 521, and the third through hole 531 are aligned. The peripheral edge of the intermediate seal 530 protrudes outward from the peripheral edges of the first glass seal 510 and the second glass seal 520. The three through holes 511, 521, and 531 are part of the oxidizer gas supply manifold 311.
[0068] There is a gap between the base plate 600 and the intermediate seal 530. Furthermore, the distance between the intermediate seal 530 and the second plate 260 is smaller than the distance between the intermediate seal 530 and the base plate 600. Similarly, the distance between the intermediate seal 530 and the third plate 610 is smaller than the distance between the intermediate seal 530 and the base plate 600. More specifically, the distance D2 between the outer circumferential surface of the intermediate seal 530 and the inner circumferential surface of the second seal hole 261 is smaller than the distance D1 between the outer circumferential surface of the intermediate seal 530 and the inner circumferential surface of the first seal hole 601. Similarly, the distance D3 between the outer circumferential surface of the intermediate seal 530 and the inner circumferential surface of the third seal hole 612 is smaller than the distance D1 between the outer circumferential surface of the intermediate seal 530 and the inner circumferential surface of the first seal hole 601.
[0069] (Manufacturing method for fuel cell stack 10) An example of a manufacturing method for the fuel cell stack 10 with the above configuration is described below.
[0070] The second plate 260, base plate 600, and third plate 610 are stacked on top of the second end plate 270 in that order. The first glass seal 510, intermediate seal 530, and second glass seal 520 are stacked inside the seal holes 261, 601, and 612 in that order. The IC separator 180E is placed on top of the third plate 610, and other components are then stacked to assemble the fuel cell stack 10. At this time, the base plate 600 plays the role of supporting the components that are stacked sequentially from below. The assembled fuel cell stack 10 is heat-treated at a heat treatment temperature higher than the operating temperature. The heat treatment temperature is, for example, 850°C. Through this heat treatment, the IC separator 180E and the intermediate seal 530 are joined by the first glass seal 510, and the intermediate seal 530 and the second end plate 270 are joined by the second glass seal 520.
[0071] (Operation of fuel cell stack 10) As shown in Figures 2 and 4, the oxidizer gas OG is supplied from the oxidizer gas supply manifold 311 to the air chamber 313 via the gas passage member 280.
[0072] Furthermore, as shown in Figures 3 and 5, the fuel gas FG is supplied from the fuel gas supply manifold 321 to the fuel chamber 323 via the gas passage member 280.
[0073] When oxidant gas OG is supplied to the air chamber 313 of each reaction unit 100U and fuel gas FG is supplied to the fuel chamber 323, electricity is generated in the single cell 110 by an electrochemical reaction between the oxidant gas OG and fuel gas FG. This power generation reaction is an exothermic reaction. As described above, the interconnector 190 is shared by two adjacent reaction units 100U, and the interconnector 190 ensures conductivity between the two adjacent reaction units 100U. In other words, the multiple reaction units 100U included in the fuel cell stack 10 are electrically connected in series. Furthermore, the second terminal plate 250 is electrically connected to the reaction unit 100U located at one end (the lower end of Figure 2), and the first terminal plate 240 is electrically connected to the reaction unit 100U located at the other end (the upper end of Figure 2). As a result, the electrical energy generated in each reaction unit 100U is extracted from the terminal plates 240 and 250, which function as output terminals of the fuel cell stack 10. Since SOFCs generate electricity at relatively high temperatures (for example, 700°C to 1000°C), the fuel cell stack 10 may be heated by a heater (not shown) after startup until the high temperature can be maintained by the heat generated by power generation.
[0074] As shown in Figures 2 and 4, the oxidizer off-gas OOG discharged from the air chamber 313 of each reaction unit 100U to the oxidizer gas discharge manifold 312 is discharged to the outside of the fuel cell stack 10 through the inside of the main body 281. Also, as shown in Figures 3 and 5, the fuel off-gas FOG discharged from the fuel chamber 323 of each reaction unit 100U to the fuel gas discharge manifold 322 is discharged to the outside of the fuel cell stack 10 through the inside of the main body 281.
[0075] The base plate 600 and the IC separator 180E are electrically connected to the single cell 110. In contrast, the second end plate 270 is insulated from the other components of the fuel cell stack 10 by the insulating second plate 260 and is not electrically connected to the single cell 110. Therefore, a potential difference is generated between the base plate 600 and the second end plate 270 when the fuel cell stack 10 is in operation.
[0076] For example, when sealing the gap between the second end plate 270 and the base plate 600 with a glass sealing member, the sealing member may peel off from the second end plate 270 due to the potential difference between the second end plate 270 and the base plate 600. The mechanism of peeling is thought to be as follows. The following description explains the case where stainless steel is used as the material for the second end plate 270, but it is thought that a similar phenomenon will occur even if other materials are used. Furthermore, the following description explains the case where the first terminal plate 240 is the positive output terminal and the second terminal plate 250 is the negative output terminal, but it is thought that a similar phenomenon will occur even if the first terminal plate 240 is the negative output terminal and the second terminal plate 250 is the positive output terminal.
[0077] When a potential difference occurs between the second end plate 270 and the base plate 600, a leakage current flows through the sealing member. At this time, the iron elements contained in the second end plate 270 are ionized, and pitting corrosion occurs on the surface of the second end plate 270. Meanwhile, components contained in the glass are ionized, and negatively charged oxygen ions move toward the positively charged second end plate 270. These oxygen ions and iron ions react, forming iron oxide between the base material and the oxide film of the second end plate 270. Alternatively, some iron elements are partially dissolved in the oxide film. As a result, the bonding strength at the interface between the second end plate 270 and the sealing member decreases. Meanwhile, an oxide film is formed again on the surface of the second end plate 270 where pitting corrosion has occurred. This causes delamination between the base material and the oxide film of the second end plate 270, and the sealing member detaches from the second end plate 270.
[0078] To reduce the occurrence of delamination, a three-layer sealing member has been proposed, comprising two glass layers and an insulating layer positioned between these two glass layers, as described above. With such a sealing member, the movement of ions in the glass is hindered by the insulating layer, which is thought to reduce the occurrence of delamination of the sealing member.
[0079] However, generally, because the gap between the second end plate 270 and the base plate 600 is narrow, when attempting to apply a three-layer sealing member, the ratio of the sum of the dimensional tolerances of each layer provided in the sealing member to the distance between the second end plate 270 and the base plate 600 becomes large. In other words, the influence of the dimensional tolerances of each layer provided in the sealing member becomes large. This raises concerns about the possibility of poor joining or damage to the sealing member. If the distance between the second end plate 270 and the base plate 600 is simply increased to solve this problem, the fuel cell stack 10 will become larger, leading to an increase in the heat dissipation of the fuel cell stack 10 and an increase in manufacturing costs.
[0080] In this embodiment, the object to be joined to the second end plate 270 via the sealing member 500 is the IC separator 180E, which is located further away from the second end plate 270 than the base plate 600. That is, as shown in Figure 7, the base plate 600 is positioned between a first virtual surface P1 including the joining surface between the second end plate 270 and the first glass seal 510, and a second virtual surface P2 including the joining surface between the IC separator 180E and the second glass seal 520. Sealing holes 261, 601, and 612 are provided in the base plate 600, the second plate 260, and the third plate 610, which are positioned between the second end plate 270 and the IC separator 180E, and the sealing member 500 is placed inside them. With this configuration, without increasing the size of the fuel cell stack 10, a large space can be secured for arranging the sealing member 500 between the second end plate 270 and the IC separator 180E, which are two members joined by the sealing member 500. As a result, the influence of dimensional tolerances of the first glass seal 510, second glass seal 520, and intermediate seal 530 provided in the sealing member 500 is reduced, and the occurrence of joining defects and cracks in the sealing member 500 is reduced.
[0081] In this embodiment, there is a gap between the base plate 600 and the intermediate seal 530. With this configuration, since the base plate 600 and the intermediate seal 530 are not in contact, leakage current flowing to the first glass seal 510 or the second glass seal 520 through the intermediate seal 530 is suppressed. As a result, the occurrence of delamination of the sealing member 500 from the second end plate 270 is reduced.
[0082] Furthermore, the distance between the intermediate seal 530 and the second plate 260 is smaller than the distance between the intermediate seal 530 and the base plate 600. Similarly, the distance between the intermediate seal 530 and the third plate 610 is smaller than the distance between the intermediate seal 530 and the base plate 600. With this configuration, contact between the base plate 600 and the intermediate seal 530 is prevented by the second plate 260 and the third plate 610, thus suppressing the flow of leakage current to the first glass seal 510 or the second glass seal 520 through the intermediate seal 530. This reduces the occurrence of delamination of the sealing member 500 from the second end plate 270.
[0083] (Effects and Benefits) As described above, the fuel cell stack 10 of this embodiment comprises a second end plate 270, an IC separator 180E, and a sealing member 500 that joins the second end plate 270 and the IC separator 180E. The sealing member 500 comprises a first glass seal 510, a second glass seal 520, and an intermediate seal 530. The first glass seal 510 is made of glass and is joined to the second end plate 270. The second glass seal 520 is made of glass and is joined to the IC separator 180E. The intermediate seal 530 is made of insulating ceramics and is placed between the first glass seal 510 and the second glass seal 520. A base plate 600 is placed between a first virtual surface P1 including the joining surface between the second end plate 270 and the first glass seal 510, and a second virtual surface P2 including the joining surface between the IC separator 180E and the second glass seal 520. The base plate 600 is electrically connected to the IC separator 180E.
[0084] With the above configuration, it is possible to secure a large space for arranging the sealing member 500 between the second end plate 270 and the IC separator 180E without increasing the size of the fuel cell stack 10. This reduces the occurrence of bonding defects and cracks in the sealing member 500.
[0085] More specifically, the base plate 600 has a first seal hole 601, and at least a portion of the seal member 500 is positioned inside the first seal hole 601.
[0086] With this configuration, space for arranging the sealing member 500 between the second end plate 270 and the IC separator 180E can be easily secured without increasing the size of the fuel cell stack 10.
[0087] There is a gap between the base plate 600 and the intermediate seal 530. With this configuration, since the base plate 600 and the intermediate seal 530 are not in contact, leakage current flowing to the first glass seal 510 or the second glass seal 520 through the intermediate seal 530 is suppressed. As a result, the occurrence of delamination of the sealing member 500 from the second end plate 270 is reduced.
[0088] The fuel cell stack 10 further comprises a second plate 260 and a third plate 610 positioned between the base plate 600 and the second end plate 270. The second plate 260 has a second seal hole 261, and the third plate 610 has a third seal hole 612. A portion of the sealing member 500 is positioned inside the second seal hole 261 and the third seal hole 612. The distance between the intermediate seal 530 and the second plate 260 is smaller than the distance between the intermediate seal 530 and the base plate 600.
[0089] With this configuration, contact between the base plate 600 and the intermediate seal 530 is prevented by the second plate 260 and the third plate 610, thus suppressing the flow of leakage current to the first glass seal 510 or the second glass seal 520 through the intermediate seal 530. This reduces the occurrence of delamination of the sealing member 500 from the second end plate 270.
[0090] B. Second Embodiment A second embodiment will be described with reference to Figure 9. In this embodiment, a second end plate 270 (an example of a first member to be joined) and a base plate 600B (an example of a second member to be joined) are joined by a first sealing member 500B (an example of a sealing member). In this embodiment, components identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted.
[0091] Similar to the first embodiment, the third plate 610, the base plate 600B, and the second plate 260 (an example of an insulating material) are arranged in this order between the IC separator 180E and the second end plate 270.
[0092] The base plate 600B has four manifold holes. The four manifold holes are holes that penetrate the base plate 600B and are parts of manifolds 311, 312, 321, and 322, respectively. Hereinafter, of the four manifold holes provided in the base plate 600B, the manifold hole that forms part of the oxidizer gas supply manifold 311 will be referred to as "manifold hole 311H3".
[0093] A second sealing member 540 is positioned inside the third sealing hole 612 of the third plate 610. The second sealing member 540 is a cylindrical member with openings at both ends. The second sealing member 540 is made of, for example, SiO2-B2O3-MgO glass. One end of the second sealing member 540 is joined to the IC separator 180E, and the other end is joined to the base plate 600B. The oxidizer gas supply manifold 311 penetrates the inside of the second sealing member 540. In other words, the internal space of the second sealing member 540 is part of the oxidizer gas supply manifold 311.
[0094] The base plate 600B has an opposing surface 602 facing the second end plate 270, and a recess 603 located on this opposing surface 602, defined by a bottom surface 604 and a side surface 605. The bottom surface 604 is located further from the second end plate 270 than the opposing surface 602 and is parallel to the opposing surface 602, while the side surface 605 connects the bottom surface 604 and the opposing surface 602 and is perpendicular to the opposing surface 602. The recess 603 is located around the manifold hole 311H3.
[0095] The recess 603 is concentric with the second seal hole 261 (an example of an insulating seal hole) provided in the second plate 260. The first seal member 500B is positioned inside the recess 603 and the second seal hole 261.
[0096] The first sealing member 500B comprises a first glass seal 510B, a second glass seal 520B, and an intermediate seal 530B, which are arranged in order.
[0097] The first glass seal 510B is an annular member made of glass and having a first through hole 511B, similar to the first embodiment. One side of the first glass seal 510 is joined to the second end plate 270, and the other side is joined to the intermediate seal 530B.
[0098] The second glass seal 520B is an annular member made of glass and having a second through hole 521B, similar to the first embodiment. One side of the second glass seal 520B is joined to the bottom surface 604 of the base plate 600B, and the other side is joined to the intermediate seal 530B.
[0099] The intermediate seal 530B, similar to the first embodiment, is an annular member formed of insulating ceramics and having a third through-hole 531B. The intermediate seal 530B is sandwiched between the first glass seal 510B and the second glass seal 520B.
[0100] The first glass seal 510B, the second glass seal 520B, and the intermediate seal 530B are concentrically arranged such that the first through hole 511B, the second through hole 521B, and the third through hole 531B are aligned. The three through holes 511B, 521B, and 531B are part of the oxidizer gas supply manifold 311.
[0101] There is a gap between the base plate 600B and the intermediate seal 530B. Furthermore, the distance between the intermediate seal 530B and the second plate 260 is smaller than the distance between the intermediate seal 530B and the base plate 600B. More specifically, the distance D2B between the outer circumferential surface of the intermediate seal 530B and the inner circumferential surface of the second seal hole 261 is smaller than the distance D1B between the outer circumferential surface of the intermediate seal 530B and the side surface 605 of the recess 603.
[0102] As described above, according to this embodiment, a portion of the base plate 600B is positioned between a first virtual surface P1 including the joining surface between the second end plate 270 and the first glass seal 510B, and a second virtual surface P2B including the joining surface between the base plate 600B and the second glass seal 520B.
[0103] With this configuration, it is possible to secure a large space for arranging the sealing member 500 between the second end plate 270 and the base plate 600B without increasing the size of the fuel cell stack 10. This reduces the occurrence of poor bonding and cracks in the sealing member 500.
[0104] More specifically, the base plate 600B comprises an opposing surface 602 facing the second end plate 270 and a recess 603 located on the opposing surface 602, with a portion of the first sealing member 500B positioned inside the recess 603.
[0105] With this configuration, a space for arranging the sealing member 500 between the second end plate 270 and the base plate 600B can be easily secured without increasing the size of the fuel cell stack 10. Furthermore, a certain thickness is ensured in the base plate 600B in all parts except the area where the sealing member 500 is joined, i.e., the area where the recess 603 is located, thereby ensuring the strength of the base plate 600B.
[0106] There is a gap between the base plate 600B and the intermediate seal 530B. With this configuration, since the base plate 600B and the intermediate seal 530B are not in contact, leakage current flowing to the first glass seal 510 or the second glass seal 520 through the intermediate seal 530 is suppressed. As a result, the occurrence of delamination of the first seal member 500B from the second end plate 270 is reduced.
[0107] The distance between the intermediate seal 530B and the second plate 260 is smaller than the distance between the intermediate seal 530B and the base plate 600B. With this configuration, contact between the base plate 600B and the intermediate seal 530B is prevented by the second plate 260, thus suppressing the flow of leakage current from the intermediate seal 530B to the first glass seal 510B or the second glass seal 520B. This reduces the occurrence of delamination of the first sealing member 500B from the second end plate 270.
[0108] C. Variations The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from their essence, for example, the following modifications are possible. (1) The first member to be joined may be a different member from the second end plate 270. The first member to be joined may be, for example, a single cell, a different member from the single cell among the members constituting the electrochemical reaction cell stack (e.g., a separator), or a stress-relieving member placed on the surface of the second end plate to relieve stress caused by external forces applied to the second end plate. Furthermore, the second member to be joined may be a different member from the IC separator 180E and the base plate 600, or a different member from the first member to be joined among the members constituting the electrochemical reaction cell stack. (2) In the above embodiment, the sealing members 500 and 500B were arranged around the manifolds 311, 312, 321, and 322, but the sealing members may be arranged in positions different from the manifolds. (3) In the first embodiment, a base plate 600, a second plate 260, and a third plate 610 were arranged between the first virtual surface P1 and the second virtual surface P2, but there may be two or more conductive members arranged between the first virtual surface and the second virtual surface. Also, there may be one insulating member or three or more insulating members arranged between the first virtual surface and the second virtual surface. (4) In the second embodiment, a part of the base plate 600B was placed between the first virtual surface P1 and the second virtual surface P2B, but both the first member to be joined and the second member to be joined may be placed between the first virtual surface and the second virtual surface. More specifically, the first member to be joined may have a first recess on the surface facing the second member to be joined, and the second member to be joined may have a second recess on the surface facing the first member to be joined, with one end of the sealing member joined to the inner wall of the first recess and the other end joined to the inner wall of the second recess. (5) In the above embodiment, the fuel cell stack 10 was equipped with a plurality of flat-plate type single cells 110, but the electrochemical reaction cell stack may be equipped with other types of single cells (for example, cylindrical, flat cylindrical). (6) The above configuration can also be applied to cell stacks used in other types of fuel cells such as polymer electrolyte fuel cells (PEFCs), phosphoric acid fuel cells (PAFCs), and molten carbonate fuel cells (MCFCs), or to electrolytic cell stacks that have electrolytic cell units, which are constituent units of solid oxide electrolytic cells (SOECs), as single cells. [Explanation of Symbols]
[0109] 10: Fuel cell stack (electrochemical reaction cell stack) 100: Power generation block 100U, 100UN: Electrochemical reaction unit 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 118: Reaction prevention layer 120: Separator for single cell 121: Through hole 124: Joint 130: Air electrode frame 131: Through hole 140: Fuel electrode frame 141: Through hole 144: Fuel electrode current collector 145: Electrode opposing part 146: Interconnector opposing part 147: Connecting part 149: Spacer 180: Separator for IC 180E: Separator for IC (Second joining target member) 181: Through hole 190: Interconnector 191: Flat plate part 192: Air electrode current collector 193: Coating layer 196: Conductive bonding material 210: First end plate 211: Flat section 212: Through hole 213: Outer protrusion 214: Inner protrusion 220: Insulating section 230: End separator 231: Through hole 232: First plate 240: First terminal plate 241: Through hole 250: Second terminal plate 251: Through hole 260: Second plate (insulating member) 261: Second seal hole (insulating seal hole) 270: Second end plate (first joining target member) 271: Flat section 272: Through hole 273: Outer protrusion 274: Inner protrusion 275: Retaining cylinder section 280: Gas passage member 281: Main body section 282: Flange section 284: Bolt hole 311: Oxidizing gas supply manifold 311H1, 311H2, 311H3: Manifold hole 312: Oxidizer gas discharge manifold 313: Air chamber 321: Fuel gas supply manifold 322: Fuel gas discharge manifold 323: Fuel chamber 500: Seal member 500B: First seal member (seal member) 510, 510B: First glass seal 511, 511B: First through hole 520, 520B: Second glass seal 521, 521B: Second through hole 530, 530B: Intermediate seal 531, 531B: Third through hole 540: Second seal member 600: Base plate (conductive member) 600B: Base plate (second joining target member) 601: First seal hole (conductive seal hole) 602: Opposing surface 603: Recess 604: Bottom surface 605: Side surface 610: Third plate 611: Through hole 612: Third sealing hole (insulating sealing hole) B: Bolt BH: Bolt hole FG: Fuel gasFOG: Fuel Off-Gas N: Nut OG: Oxidizer Gas OOG: Oxidizer Off-Gas P1: First Virtual Surface P2, P2B: Second Virtual Surface
Claims
1. The first member to be joined, The second member to be joined, The device comprises a sealing member for joining the first member to be joined and the second member to be joined, The sealing member, A first glass seal made of glass is joined to the first member to be joined, A second glass seal made of glass is joined to the second member to be joined, The system comprises an insulating ceramic intermediate seal disposed between the first glass seal and the second glass seal, A conductive member electrically connected to the second member to be joined, or a part of the second member to be joined, is positioned between a first virtual surface including the joining surface between the first member to be joined and the first glass seal, and a second virtual surface including the joining surface between the second member to be joined and the second glass seal. The conductive member is positioned between the first virtual surface and the second virtual surface. The conductive member has a conductive sealing hole, At least a portion of the sealing member is positioned inside the conductive sealing hole. Electrochemical reaction cell stack.
2. An electrochemical reaction cell stack according to Claim 1, There is a gap between the conductive member and the intermediate seal. Electrochemical reaction cell stack.
3. An electrochemical reaction cell stack according to claim 1 or claim 2, The system further comprises an insulating member disposed between the conductive member and the first member to be joined, The insulating member has an insulating seal hole, A portion of the sealing member is positioned inside the insulating sealing hole. The distance between the intermediate seal and the insulating member is smaller than the distance between the intermediate seal and the conductive member. Electrochemical reaction cell stack.
4. An electrochemical reaction cell stack according to claim 1, The second member to be joined has an opposing surface facing the first member to be joined, and a recess disposed on the opposing surface. At least a portion of the sealing member is located inside the recess. Electrochemical reaction cell stack.
5. An electrochemical reaction cell stack according to claim 4, There is a gap between the second member to be joined and the intermediate seal. Electrochemical reaction cell stack.
6. An electrochemical reaction cell stack according to claim 4 or claim 5, The device further comprises an insulating member disposed between the first member to be joined and the second member to be joined, The insulating member has an insulating seal hole, A portion of the sealing member is positioned inside the insulating sealing hole. The distance between the intermediate seal and the insulating member is smaller than the distance between the intermediate seal and the second member to be joined. Electrochemical reaction cell stack.