Electrolytic cell stack

Abstract

Suppresses gas leakage from the electrolytic cell stack. [Solution] The electrolytic cell stack comprises a first clamping plate provided at one end of the laminate in a first direction, a first clamping plate provided at the other end of the laminate containing a plurality of electrolytic cells in a first direction, and an insulating member disposed between the first clamping plate and the second clamping plate. The insulating member has a region through which gas passes in a first direction, and a first recess, which is a recess or opening disposed around the region and filled with a first sealing member that shields the gas.

Description

Technical Field

[0001] Embodiments of the present invention relate to an electrolytic cell stack.

Background Art

[0002] Electrolytic cells such as solid oxide type electrochemical cells are being developed as fuel cells for power generation, electrolyzers for hydrogen production, and power storage systems combining these. Since solid oxide type electrochemical cells use solid oxides as electrolytes, for example, they can be operated at a high operating temperature of 600°C or higher and 1000°C or lower, and a large reaction rate can be obtained without using expensive noble metal catalysts. Therefore, when this is operated as a solid oxide fuel cell (SOFC), high power generation efficiency can be obtained, and when it is operated as a solid oxide electrolytic cell (SOEC), hydrogen can be produced with high efficiency at a low electrolysis voltage. In particular, it is known that the higher the operating temperature, the higher the cell performance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to suppress gas leakage from the electrolytic cell stack.

Means for Solving the Problems

[0005] The electrolytic cell stack of the embodiment comprises a first clamping plate provided at one end of a laminate containing a plurality of electrolytic cells in a first direction, a second clamping plate provided at the other end of the laminate in a first direction, and an insulating member disposed between the first clamping plate and the second clamping plate. The insulating member has a region through which gas passes in a first direction, and a first recess, which is a recess or opening disposed around the region and filled with a first sealing member that shields the gas. [Brief explanation of the drawing]

[0006] [Figure 1] This is a schematic diagram showing an example of the structure of an electrolytic cell stack. [Figure 2] This is a schematic diagram showing an example of a laminated structure. [Figure 3] This is a schematic diagram illustrating a first embodiment of an electrolytic cell stack. [Figure 4] This is a schematic diagram showing an example of the cross-sectional shape of a recess. [Figure 5] This is a schematic diagram showing an example of the cross-sectional shape of a recess. [Figure 6] This is a schematic diagram showing an example of the cross-sectional shape of a recess. [Figure 7] This is a schematic diagram illustrating a first modified example of the first embodiment. [Figure 8] This is a schematic diagram illustrating a second modified example of the first embodiment. [Figure 9] This is a schematic diagram illustrating a second embodiment of the electrolytic cell stack. [Figure 10] This is a schematic diagram illustrating a second embodiment of the electrolytic cell stack. [Figure 11] This is a schematic diagram illustrating a modified example of the second embodiment. [Figure 12] This is a schematic diagram illustrating a third embodiment of the electrolytic cell stack. [Figure 13] This is a schematic diagram illustrating a modified example of the third embodiment. [Modes for carrying out the invention]

[0007] The embodiments will be described below with reference to the drawings. In each of the embodiments shown below, substantially identical components are denoted by the same reference numerals, and their descriptions may be partially omitted. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of the thickness of each part, etc., may differ from those in reality.

[0008] In this specification, unless otherwise specified, "connect" may include not only direct connections but also indirect connections.

[0009] (Example of an electrolytic cell stack structure) Figure 1 is a schematic diagram showing an example of the structure of an electrolytic cell stack. Figure 1 shows an example of the structure of an electrolytic cell stack 10. In this embodiment, the first direction is described as the top and the second direction as the bottom, but these directions are not limited to this case. For example, one side of the direction perpendicular to the direction of gravity (horizontal direction) may be the first direction and the other side may be the second direction, or one side of the plane oblique to the direction of gravity may be the first direction and the other side may be the second direction.

[0010] The electrolytic cell stack 10 performs an electrolytic reaction using a gas supplied from outside the electrolytic cell stack 10 (supply gas) and can discharge the gas produced by the electrolytic reaction (generated gas). The supply gas is supplied from a gas supply source outside the electrolytic cell stack 10 and includes, for example, water vapor, carbon dioxide gas, and hydrogen gas. The generated gas includes, for example, carbon monoxide gas and hydrogen gas. The electrolytic cell stack 10 has a laminate 1, a lower clamping plate 2, an upper clamping plate 3, and insulating members 5 (5a, 5b). The laminate 1, the lower clamping plate 2, the upper clamping plate 3, and the insulating members 5 can be connected and fixed by fasteners (connectors) that penetrate these components, for example. Examples of fasteners include combinations of bolts and nuts and springs.

[0011] The laminate 1 is a solid oxide type electrochemical stack having a solid oxide type electrochemical cell 11. The laminate 1 is provided between a lower clamping plate 2 and an upper clamping plate 3. The lower clamping plate 2 (the first clamping plate in the present embodiment) is provided, for example, on the lower side of the laminate 1 (one end of the laminate 1 in the present embodiment). The upper clamping plate 3 (the second clamping plate in the present embodiment) is provided, for example, on the upper side of the laminate 1 (the other end of the laminate 1 in the present embodiment). The lower clamping plate 2 and the upper clamping plate 3 are, for example, metal plates. The metal plate is a conductor. Examples of the metal plate include stainless steel (SUS) and nickel (Ni) alloy. In the present embodiment, the case where one end of the laminate 1 is on the upper side of the laminate 1 and the other end is on the lower side of the laminate 1 has been illustrated and described. However, for example, the side surfaces of the laminate 1 may be used as one end and the other end. That is, the first clamping plate and the second clamping plate in this embodiment may be provided on one side surface of the laminate 1 and the other side surface facing this side surface, respectively.

[0012] FIG. 2 is a schematic cross-sectional view showing a structural example of the laminate 1. The laminate 1 has a solid oxide type electrochemical cell 11. FIG. 2 shows a flat stack having a plurality of solid oxide type electrochemical cells 11. The laminate 1 is not limited to a flat stack, and may be, for example, a cylindrical stack. The solid oxide type electrochemical cell 11 is a flat type electrochemical cell and a fuel electrode supported type cell. The solid oxide type electrochemical cell 11 is connected to a power source that can supply, for example, a voltage or a current for performing an electrolysis reaction.

[0013] The solid oxide type electrochemical cell 11 can be operated at a high temperature, and the electrolysis reaction is performed, for example, at a temperature of 600 ° C or higher and 1000 ° C or lower. The solid oxide type electrochemical cell 11 may be provided, for example, in a heater, and the temperature may be adjusted by a heater that heats the solid oxide type electrochemical cell 11. The solid oxide type electrochemical cell 11 may be provided in an electric furnace that can control the temperature of the solid oxide type electrochemical cell 11.

[0014] A plurality of solid oxide type electrochemical cells 11 are stacked in sequence. The solid oxide type electrochemical cell 11 has an air electrode 101, an electrolyte 102, a fuel electrode 103, and a support 104.

[0015] The electrolysis reaction by the electrolytic cell stack 10 is performed as follows, for example. Gases such as carbon dioxide gas, water vapor, and hydrogen gas are supplied to the fuel electrode 103 side. By the electrolysis reaction at the fuel electrode 103, hydrogen gas can be generated from water vapor, for example, and carbon monoxide gas can be generated from carbon dioxide gas. Gases such as carbon dioxide gas, water vapor, hydrogen gas, and carbon monoxide gas are discharged from the fuel electrode 103 side.

[0016] Gases such as air are supplied to the air electrode 101 side. The air is supplied, for example, to purge oxygen generated during electrolysis. Oxygen can be generated by the electrolysis reaction at the air electrode 101. Air having an oxygen concentration higher than the oxygen concentration in the atmosphere is discharged from the air electrode 101 side.

[0017] The air electrode 101 has, for example, a porous electric conductor. Examples of the porous electric conductor include perovskite type oxides and the like.

[0018] The air electrode 101 further has, for example, a catalyst that promotes the electrolysis reaction contained in the product gas. The catalyst contains at least one element of platinum (Pt), ruthenium (Ru), cerium (Ce), lanthanum (La), cobalt (Co), nickel (Ni), aluminum (Al), and copper (Cu), for example. The catalyst is supported on the surface of the electric conductor, for example. The catalyst may form a catalyst layer provided on the surface of the electric conductor.

[0019] The electrolyte 102 has, for example, an ion conductor that does not conduct electricity. Examples of the ion conductor include solid oxides such as stabilized zirconia, perovskite type oxides, and formed bodies of ceria-based solid solutions.

[0020] The fuel electrode 103 has, for example, a porous electrical conductor. Examples of porous electrical conductors include mixed sintered bodies of metal and solid oxides (cermets). Examples of mixed sintered bodies include yttria-stabilized zirconia and scandia-stabilized zirconia.

[0021] The electrolytic cell stack 10 can isolate the atmospheres of adjacent solid oxide electrochemical cells 11, for example, by a separator 121. Furthermore, the atmospheres of the fuel electrode 103 and air electrode 101 of the same solid oxide electrochemical cell 11 can be isolated by providing a partition plate 122 on the dense electrolyte 102 of the solid oxide electrochemical cell 11. The solid oxide electrochemical stack may further have a sealing member 123 between the partition plate 122 and the separator 121. The electrolytic cell stack 10 may further have a plurality of gas channels on the outer periphery of the solid oxide electrochemical cells 11 that penetrate along the stacking direction of the solid oxide electrochemical cells 11. One of the plurality of gas channels constitutes a channel for the raw material gas supplied to the fuel electrode 103 and air electrode 101, respectively, and for the reaction product gas generated by the fuel electrode 103 and air electrode 101. Another of the plurality of gas channels may be connected to piping, for example.

[0022] To generate a large amount of electricity and hydrogen, an electrolytic cell stack 10 is formed by stacking multiple solid oxide type electrochemical cells 11. For example, in the case of a flat-plate type electrolytic cell, the electrolytic cell stack 10 is formed by stacking multiple flat-plate type electrolytic cells, supplying different gases to the air electrode 101 and fuel electrode 103 of each electrolytic cell, and having a structure that allows the electrolytic cells to be electrically connected in series.

[0023] The laminate 1, lower clamping plate 2, upper clamping plate 3, and insulating member 5 can be fastened together by applying compressive force in the stacking direction using, for example, a combination of bolts and nuts or a compression mechanism (fastener) such as a spring. This ensures electrical contact within the laminate. The electrolytic cell stack 10 is sealed by the lower clamping plate 2 and upper clamping plate 3 positioned above and below the laminate 1, which apply compressive force in the stacking direction, particularly preventing hydrogen generated by the electrolytic reaction from leaking to the outside of the electrolytic cell stack 10.

[0024] The insulating member 5 allows gas to pass through in the stacking direction of the electrolytic cell stack 10. The insulating member 5 is provided between the lower clamping plate 2 and the upper clamping plate 3. The insulating member 5 is provided, for example, between the laminate 1 and the lower clamping plate 2 or between the laminate 1 and the upper clamping plate 3. The laminate 1 and the lower clamping plate 2 or the upper clamping plate 3 are in close contact with the insulating member 5 in between. However, it is not limited to this, and the insulating member 5 may be provided inside the laminate 1. For example, the insulating member 5 may be applied to the sealing member 123 in Figure 2.

[0025] The electrolytic cell stack 10 improves output by stacking multiple flat-plate cells, and depending on the number of stacked cells, the voltage at the ends can exceed 100V. In the case of a flat-plate electrolytic cell stack 10, gas to each electrode is supplied from the lower clamping plate 2 or the upper clamping plate 3. Therefore, the insulating member 5 is required to have two functions: insulating performance and sealing performance. In particular, it is important to prevent the hydrogen generated in the electrolytic reaction from leaking to the outside.

[0026] Because the operating temperature of the solid oxide electrochemical cell 11 is high, the insulating material 5 is an inorganic material made by compressing natural minerals such as vermiculite or mica with an adhesive. Due to the manufacturing method and properties of the material, inorganic materials are generally used that are solidified in layers in the planar direction, or that are made by compressing granular or short layers in the planar direction. As a result, the adhesive leaches out at the operating temperature, creating gaps between layers and between materials, and inevitably forming leak paths inside the insulating material 5, causing gas leakage.

[0027] In contrast, the electrolytic cell stack of the embodiment has a structure that shields the gas around the region through which the gas passes in the insulating member 5. An example of an electrolytic cell stack 10 having the above structure will be further described below.

[0028] (First Embodiment) Figure 3 is a schematic diagram illustrating a first embodiment of the electrolytic cell stack 10. Figure 3 schematically shows an example of the planar structure of the insulating member 5 provided in the electrolytic cell stack 10 shown in Figure 1.

[0029] The insulating member 5 has a region 51, a gas hole 52, and a recess 53. Since the insulating member 5 is formed by stacking multiple insulators, for example, gas leakage is predominant in the direction perpendicular to the stacking direction (direction perpendicular to the stacking direction) rather than in the stacking direction (thickness direction) of the electrolytic cell stack 10.

[0030] Region 51 is provided, for example, in a region including the center of the surface of the insulating member 5, and overlaps with the solid oxide type electrochemical cell 11 and the current collector in the stacking direction.

[0031] The gas holes 52 are regions through which gas can pass in the stacking direction. The gas holes 52 are connected, for example, to the gas flow path of the stacked body 1. The gas holes 52 are provided in region 51. The gas holes 52 are through holes that penetrate the insulating member 5 along the thickness direction (stacking direction). The gas necessary for fuel cell reactions and electrolytic reactions can be supplied and discharged through the gas holes 52.

[0032] The recess 53 is provided on the surface of the insulating member 5 around the gas hole 52. In Figure 3, the recess 53 may be provided in an annular shape so as to continuously surround the gas hole 52. Examples of the recess 53 include indentations or openings. An indentation may be a groove or notch provided on the surface of the insulating member 5 without penetrating along the lamination direction. An opening may be a through hole penetrating the insulating member 5 along the lamination direction.

[0033] Figures 4, 5, and 6 are schematic diagrams showing examples of the cross-sectional shape of the recess 53. Figures 4, 5, and 6 schematically show a part of the cross-section of the insulating member 5 in the thickness direction. The insulating member 5 is formed, for example, by layering a plurality of insulators 50a in the stacking direction and pressing them together with an adhesive. Each of the plurality of insulators 50a is an inorganic material formed by pressing natural ores such as vermiculite or mica with an adhesive. Figure 4 shows an example in which the recess 53 is an opening that penetrates the insulating member 5 in the thickness direction. Figure 5 shows an example in which the recess 53 is a recess provided on one side of the insulating member 5 without penetrating in the thickness direction. Figure 6 shows an example in which the recess 53 is a recess provided on both sides of the insulating member 5 without penetrating in the thickness direction. In Figures 5 and 6, the shape of the recess is shown as having a semicircular tip, but it is not limited to this, and the cross-sectional shape may be rectangular or a rectangular shape with a fillet at the end.

[0034] In Figures 4, 5, and 6, the recess 53 is provided on the surface 5a of the insulating member 5 or on the surface 5b opposite to surface 5a. The recess 53 is filled with, for example, a sealing member 54. In the case of a solid oxide type electrolytic cell stack that operates in a high-temperature environment, the sealing member 54 is preferably formed mainly of glass material. Here, "mainly of glass material" refers to glass material formed by mixing a glass filer and a binder to make a slurry and then drying it, wherein the glass content after drying is 50% or more.

[0035] The thickness t of the insulating material 5 depends on the required insulating performance, but is, for example, 0.2 mm or more and 1.0 mm or less.

[0036] The width d of the recess 53 is not particularly limited as long as it can be sealed by the sealing member 54, but due to manufacturing constraints, it is preferably, for example, 0.02 mm or more and 0.5 mm or less.

[0037] The greater the depth h of the recess 53 relative to the thickness t, the better the sealing performance by the sealing member 54. However, from the viewpoint of the strength and insulation performance of the laminated member, a depth h of 90% or less of the thickness t is preferable. The lower limit of the depth h is not particularly limited. For example, by making it 50% or more of the thickness t, the decrease in insulation performance can be suppressed and the gas leak suppression effect can be enhanced. Also, by making it less than 50% of the thickness t, the strength of the laminated member can be increased.

[0038] The recess 53 shown in Figure 4 separates the insulating member 5 into the portion containing the gas hole 52 (the portion inside the recess 53 of the insulating member 5) and the other portion (the portion outside the recess 53 of the insulating member 5), requiring positional adjustment during the manufacturing of the electrolytic cell stack 10 and increasing the number of components. The recess 53 shown in Figure 5 has the advantage of being easy to assemble without the aforementioned increase in the number of components. The recess 53 shown in Figure 6 can suppress gas leakage while ensuring the rigidity of the insulating member 5. In Figure 6, it is preferable that the depth h of the recess 53 is at least 50% of the thickness t.

[0039] By arranging recesses 53 filled with sealing members 54 around the gas holes 52 of the insulating member 5, gas leakage from the electrolytic cell stack 10 can be suppressed, for example.

[0040] Figure 7 is a schematic diagram illustrating a first modification of the first embodiment. Figure 7 schematically shows an example of the planar structure of an insulating member 5 provided in the electrolytic cell stack 10 shown in Figure 1. Figure 7 shows the insulating member 5. The insulating member 5 shown in Figure 7 has recesses 53 that extend between adjacent gas holes 52 of the insulating member 5. In other words, the recesses 53 extend not only around each gas hole 52 but also between adjacent gas holes 52. That is, the recesses 53 extend continuously in an annular shape along the periphery of the surface of the insulating member 5. The recesses 53 are filled with sealing members 54, similar to the recesses 53 shown in Figures 4 to 6. The insulating member 5 shown in Figure 7 can suppress gas leakage not only around the gas holes 52 but also from the region 51 where the electrolytic reaction occurs toward the corners of the surface of the insulating member 5.

[0041] As shown in Figure 7, the recess 53 may be provided with an annular region that surrounds the gas hole 52 and has a cut X. By forming a cut X so that the planar shape of the recess 53 is not a single continuous line, the insulating member 5 can be made into a single member without being separated into multiple parts, thereby preventing an increase in the number of parts. Figure 7 shows an example with multiple cuts X, but the number of cuts X is not particularly limited.

[0042] Figure 8 is a schematic diagram illustrating a second modification of the first embodiment. Figure 8 schematically shows an example of the planar structure of an insulating member 5 provided in the electrolytic cell stack 10 shown in Figure 1. Figure 8 shows an example having double recesses 53 around a gas hole 52. The insulating member shown in Figure 8 shows a plurality of recesses 53 (recesses 53a, recesses 53b), but the number of recesses 53 is not particularly limited as long as it is two or more, and there may be three or more recesses 53. Recesses 53a are provided in an annular shape surrounding the gas hole 52. Recesses 53b are provided in an annular shape surrounding recess 53a. The plurality of recesses 53 are filled with a sealing member 54, similar to the recesses 53 shown in Figures 4 to 6. By providing a plurality of recesses 53, gas leakage can be suppressed in multiple stages, thereby improving sealing performance. Recesses 53a may be provided on the surface 5a shown in Figure 6, for example, and recesses 53b may be provided on the surface 5b shown in Figure 6, for example.

[0043] Each of the recesses 53a and 53b may be provided in an annular shape with a gap X, as in Figure 7. By forming the gap X, the gas leak path can be lengthened, and the sealing performance can be improved. Furthermore, by arranging the gap X of recess 53a and the gap X of recess 53b so that they do not overlap (are not adjacent), a decrease in sealing performance can be suppressed.

[0044] (Second embodiment) Figures 9 and 10 are schematic diagrams illustrating a second embodiment of the electrolytic cell stack. Figure 9 is a schematic plan view showing the insulating member 5 and the lower clamping plate 2. Figure 10 is a schematic cross-sectional view in the thickness direction showing the insulating member 5 and the lower clamping plate 2. The following describes the parts that differ from the first embodiment, and for other parts, the description of the first embodiment can be appropriately referenced.

[0045] As shown in Figure 10, the electrolytic cell stack 10 of the second embodiment has a recess 20 on the surface of the lower clamping plate 2, and the insulating member 5 is arranged in the recess 20.

[0046] An example of the recess 20 is a notch provided on the surface of a metal member such as the lower clamping plate 2. The recess 20 has an area that is slightly larger than the area of ​​the laminate 1 and the insulating member 5 in the plane shown in Figure 9. The periphery of the recess 20 may continuously surround the laminate 1 and the insulating member 5 in the plane shown in Figure 9.

[0047] The insulating member 5 is positioned to fit within the recess 20. In the plane shown in Figure 9, the insulating member 5 may be continuously surrounded, for example, by the periphery of the recess 20. Further description of the insulating member 5 can be appropriately based on the description of the first embodiment.

[0048] A gap S is formed between the side surface of the insulating member 5 and the inner wall surface of the recess 20. Preferably, the gap S is filled with a sealing member 6. The sealing member 6 can seal the space between the insulating member 5, the laminate 1, and the lower clamping plate 2. Gas leakage from the insulating member 5 can be suppressed by the sealing member 6. In the case of a solid oxide type electrolytic cell stack that operates at high temperatures, it is preferable that the sealing member 6 is mainly composed of glass material. Here, "mainly composed of glass material" means glass material formed by mixing a glass filer and a binder to make a slurry and then drying it, wherein the glass content after drying is 50% or more.

[0049] Figure 11 is a schematic diagram illustrating a modified example of the second embodiment. Figure 11 is a schematic cross-sectional view in the thickness direction showing the insulating member 5 and the lower clamping plate 2. Figure 11 further shows the insulating member 7 and a plurality of sealing members 6 (6a, 6b). As shown in Figure 11, the insulating member 7 may be arranged around the insulating member 5.

[0050] The insulating member 7 is provided in contact with the insulating member 5. The insulating member 7, like the insulating member 5, is formed, for example, by layering multiple insulators in the lamination direction or perpendicular to the lamination direction and pressing them together with an adhesive. Each of the multiple insulators is an inorganic material formed by pressing natural minerals such as vermiculite or mica with an adhesive. The gap S1 between the side surface of the insulating member 7 and the side surface of the recess 20 is filled with a sealing member 6a. The gap S2 between the insulating member 7 and the laminate 1 is filled with a sealing member 6b. It is preferable that the sealing members 6a and 6b are mainly composed of glass material. Here, "mainly composed of glass material" means glass material formed by mixing a glass filer and a binder to make a slurry and drying it, wherein the glass content after drying is 50% or more.

[0051] When a sealing member 6 is present between the side surface of the laminate 1 and the side surface of the recess 20 of the lower clamping plate 2, leakage current may increase at the location of the sealing member 6. In contrast, by placing an insulating member 7, it is possible to improve sealing performance without reducing insulation performance.

[0052] Furthermore, the insulating member 7 is not limited to being a separate member from the insulating member 5, and a single insulating member may have a first portion that forms the insulating member 5 and a second portion that forms the insulating member 7. For example, in the plane shown in Figure 9, the insulating member 5 and the insulating member 7 may be formed by pressing and compressing a region including the center of a single insulating member having an area slightly larger than the area of ​​the laminate 1 to form a recess.

[0053] The second embodiment can suppress gas leakage from the inside to the outside of the laminate 1, but by combining it with the first embodiment, the gas leakage effect can be enhanced. For example, by applying the electrolytic cell stack 10 of the second embodiment, in which the insulating member 5 of the first embodiment is applied to the inside of the laminate 1 (e.g., the sealing member 123), gas can be suppressed both inside and outside the laminate 1.

[0054] The second embodiment is not limited to cases where gas is supplied and discharged from the lower clamping plate 2, but a similar seal performance improvement effect can be obtained even when the gas supply unit is located in the upper clamping plate 3 or in the center of the laminate 1.

[0055] (Third embodiment) Figure 12 is a schematic diagram illustrating a third embodiment of the electrolytic cell stack 10. Figure 12 is a schematic cross-sectional view in the thickness direction showing the insulating member 5 and the lower clamping plate 2.

[0056] As shown in Figure 12, the electrolytic cell stack 10 of the third embodiment has a configuration in which the insulating member 5 consists of a plurality of insulators 50b.

[0057] Multiple insulators 50b are formed by arranging them in layers perpendicular to the lamination direction and pressing them together with an adhesive. The multiple insulators 50b are made of inorganic materials such as vermiculite or mica, which are pressed together with an adhesive. As in the first embodiment, in an insulating member 5 having insulators 50a arranged in layers in the lamination direction, gas leakage is predominantly in the direction perpendicular to the lamination direction. In contrast, by constructing the insulating member 5 using multiple insulators 50b arranged in layers in the vertical direction, gas leakage can be suppressed.

[0058] Figure 13 is a schematic diagram illustrating a modified example of the third embodiment. Figure 13 is a schematic cross-sectional view in the thickness direction showing the insulating member 5 and the lower clamping plate 2. As shown in Figure 13, the insulating member 5 may be constructed by combining a plurality of insulators 50a and a plurality of insulators 50b.

[0059] Multiple insulators 50a are surrounded by multiple insulators 50b. The multiple insulators 50a are formed by being arranged in layers in the stacking direction of the insulating member 5 and pressed together with adhesive. Further description of the multiple insulators 50a can be appropriately referenced from the description of the first embodiment.

[0060] Multiple insulators 50b are surrounded by multiple insulators 50a. The multiple insulators 50b are formed by being arranged in layers in the lamination direction (planar direction) of the insulating member 5 and being pressed together with adhesive. Further explanation of the multiple insulators 50b can be found in the explanation of the multiple insulators 50b shown in Figure 12.

[0061] If there are gaps between multiple insulators 50a and multiple insulators 50b, it is preferable to fill the gaps with a sealing member 8 to seal the multiple insulators 50a. The sealing member 8 is preferably mainly composed of glass material. Here, "mainly composed of glass material" refers to glass material formed by mixing a glass filer and a binder to make a slurry and then drying it, wherein the glass content after drying is 50% or more.

[0062] When forming an insulating member 5 using multiple insulators arranged in layers perpendicular to the stacking direction, there may be issues with manufacturing the insulating member 5 depending on the stack size and shape, as well as with its strength when compressed within the stack. In contrast, an insulator 50a arranged perpendicular to the stacking direction and an insulator 50b arranged in layers in the stacking direction may be combined.

[0063] The third embodiment can suppress gas leakage from the inside to the outside of the laminate 1, but by combining it with at least one of the first and second embodiments, it is possible to suppress both gas leakage occurring inside the laminate 1 and gas leakage from the inside to the outside of the laminate 1, for example, thus providing a structure that can more effectively suppress gas leakage occurring in the electrolytic cell stack 10.

[0064] The third embodiment is not limited to the ends of the laminate 1, but when the insulating member 5 is applied inside the laminate 1, for example, inter-electrode gas leakage between the fuel electrode and the air electrode inside the laminate 1 can be suppressed. For example, by applying the insulating member 5 in the third embodiment to the inside of the laminate 1 (for example, the sealing member 123), gas can be suppressed both inside and outside the laminate 1.

[0065] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0066] 1...Laminate, 2...Lower clamping plate, 5...Insulating member, 5a...Surface, 5b...Surface, 6...Sealing member, 6a...Sealing member, 6b...Sealing member, 7...Insulating member, 8...Sealing member, 10...Electrolytic cell stack, 11...Solid oxide type electrochemical cell, 20...Recess, 50a...Insulator, 50b...Insulator, 51...Region, 52...Gas hole, 53...Recess, 53a...Recess, 53b...Recess, 54...Sealing member, 101...Air electrode, 102...Electrolyte, 103...Fuel electrode, 104...Support, 121...Separator, 122...Partition plate, 123...Sealing member, S...Gap, S1...Gap, S2...Gap.

Claims

1. A first clamping plate is provided at one end of a laminate containing a plurality of electrolytic cells in a first direction, A second clamping plate provided at the other end of the laminate in the first direction, An insulating member disposed between the first clamping plate and the second clamping plate, It is equipped with, The insulating member is The region through which the gas passes in the first direction, A first recess is a recess or opening which is arranged around the region and filled with a first sealing member that shields the gas, Having, Electrolytic cell stack.

2. The first recess extends in an annular shape, enclosing the region and having at least one break. The electrolytic cell stack according to claim 1.

3. The insulating member is Multiple of the above-mentioned first recesses, A first surface having one of the plurality of first recesses, A second surface having another of the plurality of first recesses, It has, One of the plurality of first recesses extends in an annular shape so as to surround the region, Another of the plurality of first recesses extends in an annular shape so as to surround one of the plurality of first recesses. The electrolytic cell stack according to claim 1.

4. The laminate is in close contact with the first clamping plate or the second clamping plate, with the insulating member sandwiched between them. The electrolytic cell stack according to claim 1.

5. The first sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 1.

6. A first clamping plate is provided at one end of a laminate containing a plurality of electrolytic cells in a first direction, A second clamping plate provided at the other end of the laminate in the first direction, An insulating member disposed between the first clamping plate and the second clamping plate, It is equipped with, The insulating member has a region through which gas passes in the first direction, The first clamping plate or the second clamping plate has a second recess which is a notch, The insulating member is placed in the second recess and sealed by a second sealing member provided between the side surface of the insulating member and the inner wall surface of the second recess. Electrolytic cell stack.

7. The first clamping plate or the second clamping plate has a second recess which is a notch, The insulating member is placed in the second recess and sealed by a second sealing member provided between the side surface of the insulating member and the inner wall surface of the second recess. The electrolytic cell stack according to claim 1.

8. The second sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 6 or claim 7.

9. The insulating member includes a plurality of first insulators arranged in layers in the first direction. The electrolytic cell stack according to claim 1 or claim 6.

10. A first clamping plate is provided at one end of a laminate containing a plurality of electrolytic cells in a first direction, A second clamping plate provided at the other end of the laminate in the first direction, An insulating member disposed between the first clamping plate and the second clamping plate, It is equipped with, The insulating member has a region through which gas passes in the first direction and includes a plurality of second insulators arranged in layers in a second direction perpendicular to the first direction. Electrolytic cell stack.

11. The insulating member further includes a plurality of first insulating members that are surrounded by the plurality of second insulating members and arranged in layers in the first direction. The electrolytic cell stack according to claim 10.

12. The first plurality of insulators are sealed by a third sealing member provided between the first plurality of insulators and the second plurality of insulators. The electrolytic cell stack according to claim 11.

13. The third sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 12.

14. The insulating member is A plurality of first insulators arranged in layers in the first direction, A second plurality of insulators surrounds the first plurality of insulators and is provided in layers in a second direction perpendicular to the first direction, Includes, The first plurality of insulators are sealed by a third sealing member provided between the first plurality of insulators and the second plurality of insulators. The electrolytic cell stack according to claim 1.

15. The third sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 14.

16. The insulating member is A plurality of first insulators arranged in layers in the first direction, A second plurality of insulators surrounds the first plurality of insulators and is provided in layers in a second direction perpendicular to the first direction, Includes, The first plurality of insulators are sealed by a third sealing member provided between the first plurality of insulators and the second plurality of insulators. The electrolytic cell stack according to claim 6.

17. The third sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 16.

18. The first clamping plate or the second clamping plate has a second recess which is a notch, The insulating member is placed in the second recess and sealed by a second sealing member provided between the side surface of the insulating member and the inner wall surface of the second recess. The insulating member is A plurality of first insulators arranged in layers in the first direction, A second plurality of insulators surrounds the first plurality of insulators and is provided in layers in a second direction perpendicular to the first direction, Includes, The first plurality of insulators are sealed by a third sealing member provided between the first plurality of insulators and the second plurality of insulators. The electrolytic cell stack according to claim 1.

19. The third sealing member is mainly composed of glass material, The electrolytic cell stack according to claim 18.

20. The insulating member includes vermiculite or mica. The electrolytic cell stack according to any one of claims 1, 6, and 10.

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