Electrochemical module and energy system

Abstract

To provide an electrochemical module including a gas seal portion that is resistant to cracking, has high temperature stability, and exhibits high gas sealing properties under a small load, and an energy system equipped with the electrochemical module.SOLUTION: An electrochemical module M is provided in which an electrochemical element A and another adjacent electrochemical element A are provided with a gas seal portion 300 that seals a second gas different from the first gas on at least two opposing sides of the four sides of the plate-like support 10 of each electrochemical element A, and the gas seal portion 300 includes a gas seal structure GS that is affected by the clamping pressure of a first clamping body 201 and a second clamping body 203, and the gas seal portion 300 includes a gas seal material 301 that contains fibrous particles and a silicon-based compound, has a density of 0.50 to 1.0 g / cm3, and has a ratio of (load required for 20% compression) / (load required for 15% compression) in the range of 50 to 400.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electrochemical module and an energy system including the electrochemical module. [Background technology]

[0002] Patent document 1 describes a fuel cell (electrochemical module) that includes a stack formed by stacking multiple flat fuel cell cells, a gas flow path formed along the stacking direction of the stack and through which either a fuel gas or an oxidizer gas flows to be supplied to each of the multiple fuel cell cells, and a gas seal portion formed in the gas flow path between adjacent first and second plate members of the stack to prevent gas flowing through the gas flow path from leaking into the gap layer between the first and second plate members.

[0003] It is described that the gas seal portion includes a glass member that contacts the first plate member along the stacking direction.

[0004] Patent Document 2 describes the structure of a fuel cell stack comprising a single fuel cell cell, a separator for the single cell, an air electrode side frame, a fuel electrode side frame, a fuel electrode side current collecting member, a pair of interconnectors and a pair of IC separators that form the top and bottom layers of the power generation unit.

[0005] The air electrode side frame is in contact with the upper surface of the peripheral portion of the single cell separator and the lower surface of the peripheral portion of the upper IC separator, and functions as a sealing member that ensures gas sealing between the two. It is described that the air electrode side frame is made of an insulating material such as mica.

[0006] US Pat. No. 5,699,949 describes a high temperature gas seal used in a planar solid oxide fuel cell stack under compression by adjacent fuel cells. The high-temperature gas seal is described as containing 5-40% by mass of ceramic fibers, 50-90% by mass of ceramic powder, and 2-5% by mass of an organic binder. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6740856 [Patent Document 2] Japanese Patent Publication No. 2022-17724 [Patent Document 3] Patent No. 5981695 Summary of the Invention [Problem to be solved by the invention]

[0008] When a glass member is provided in the gas seal portion as in Patent Document 1, there is a risk of cracks occurring due to the difference in thermal expansion coefficient with the support body caused by temperature changes during start-up and shutdown of the solid oxide fuel cell (SOFC). Furthermore, the glass member contains components that reduce the catalytic activity of the electrode, and these components may be scattered onto the electrode during high-temperature operation, reducing the performance of the SOFC.

[0009] The sealing members used in Patent Documents 2 and 3 are made of an insulating material such as mica or ceramic fiber, which are considered to have high stability at high temperatures.

[0010] When an insulator such as mica is used as a sealing material as described in Patent Document 2, sealing properties can be ensured by applying a load. However, due to its incompressibility, a high load must be applied, which places restrictions on the SOFC unit and stack structure.

[0011] Furthermore, when ceramic fibers are used as a sealing material as described in Patent Document 3, ceramic fiber-based sealing materials have the advantage of having sufficient compressibility and not cracking, but there is a problem in that sufficient sealing properties cannot be obtained due to their high porosity.

[0012] Therefore, an object of the present invention is to provide an electrochemical module having a gas sealing portion that is less susceptible to cracking, has high temperature stability, and exhibits high gas sealing properties under a small load, and an energy system equipped with the electrochemical module. [Means for solving the problem]

[0013] The electrochemical module according to the present invention for achieving the above object comprises: a stack in which a plurality of electrochemical elements, each having an electrolyte layer and an electrode layer and a counter electrode layer disposed on either side of the electrolyte layer, are stacked in a predetermined stacking direction via an annular seal for passing a first gas, which is one of a reducing component gas and an oxidizing component gas, along a plate-like support; and a container having a first sandwiching body and a second sandwiching body, the first sandwiching body and the second sandwiching body being disposed so as to apply a predetermined clamping pressure to the stack, and the stack is housed therein. The electrochemical module is characterized in that the electrochemical element and another electrochemical element adjacent to the electrochemical element either above or below in the stacking direction are provided with gas seals on at least two opposing sides of the four sides of the plate-like support for sealing in a second gas different from the first gas, the gas seals having a gas seal structure that is affected by the clamping pressure exerted by the first sandwiching body and the second sandwiching body, and the gas seals contain fibrous particles and a silicon-based compound and have a density of 0.50 to 1.0 g / cm. 3 The gas seal material has a ratio of (load required for 20% compression) / (load required for 15% compression) in the range of 50 to 400.

[0014] The electrochemical module includes a stack of multiple electrochemical elements, and the stack can be housed inside a container while being pressed and clamped by a first clamping body and a second clamping body. By pressing and clamping the stack between the two clamping bodies in this way, members provided between adjacent electrochemical elements can be arranged so as to be in close contact with both electrochemical elements.

[0015] According to this configuration, an electrochemical element and another electrochemical element adjacent to the electrochemical element in either the upside or downside in the stacking direction are provided with gas seals for sealing in the second gas on at least two opposing sides of the four sides of the plate-like support, so that the gas seals can be disposed on the periphery of the plate-like support between the two electrochemical elements so as to be in close contact with both electrochemical elements. In other words, the gas seals can provide gas sealing properties against the second gas between the adjacent electrochemical elements.

[0016] The gas seal portions are disposed on at least two opposing sides of the four sides of the plate-shaped support body. For example, when the gas seal portions are disposed on two opposing sides, the two sides on which the gas seal portions are disposed can be provided with gas sealing properties against the second gas.

[0017] Furthermore, since the laminate is pressed and sandwiched between the two sandwiching bodies, the gas seal portion has a gas seal structure to which the clamping pressure of these sandwiching bodies is applied, and thus the gas seal structure can be configured to compress the gas seal portion at the peripheral edge of the plate-shaped support body.

[0018] The gas seal portion contains fibrous particles and silicon-based compounds and has a density of 0.50 to 1.0 g / cm 3 and the ratio of (load required for 20% compression) / (load required for 15% compression) is in the range of 50 to 400.

[0019] The fibrous particles and silicon-based compounds can be chemically stable materials, which makes it difficult for cracks to occur inside the electrochemical module, and allows the gas seal portion (gas seal material) to be disposed in a chemically stable state.

[0020] If the density is within the above range, the second gas is less likely to pass through the gas sealing material, and when the gas sealing material comes into contact with the sealing surface (the surface of the peripheral edge of the plate-shaped support body), it deforms and can make good contact with the sealing surface, thereby providing good gas sealing properties against the second gas.

[0021] The density is the above lower limit (0.50 g / cm 3 ), the second gas will easily permeate the gas sealing material, and the gas sealing performance of the gas sealing material may be significantly impaired. 3 ), if there are locally thick areas in the gas sealing material, only those thick areas will come into contact with the sealing surface (the surface of the peripheral edge of the plate-shaped support body), preventing the gas sealing material from deforming sufficiently, and areas other than those thick areas will not come into contact with the sealing surface, which could result in a decrease in gas sealing performance.

[0022] Furthermore, if the ratio of (load required for 20% compression) / (load required for 15% compression) is in the range of 50 to 400, when the gas seal material is disposed in the gas seal portion to form a gas seal structure, a leak path for the second gas is unlikely to occur in the gas seal portion, and the load required to form the gas seal structure is unlikely to become large.

[0023] If the value is smaller than the lower limit (50), when the gas seal material is disposed in the gas seal portion to form a gas seal structure, a leak path for the second gas is likely to occur in the gas seal portion, and the gas sealing properties of the gas seal material (gas seal structure) may be impaired. On the other hand, if the value is larger than the upper limit (400), the load required to form the gas seal structure increases, requiring a heavy load application process such as bolt tightening. In addition, the load that should be distributed to the cell and interconnector joints, etc., is consumed by the gas seal material, increasing the resistance value and potentially causing a deterioration in electrochemical performance.

[0024] In the examples described below, it has been confirmed that the electrochemical module of the present invention has high temperature stability and a gas seal portion that exhibits high gas sealing properties under a small load.

[0025] A further characteristic feature of the electrochemical module according to the present invention is that the boron content in the gas sealing material is set to 100 to 2000 ppm.

[0026] According to this configuration, if the boron content is within the above range, the content of boron, which is a catalyst poisoning substance that reduces the catalytic activity of the electrodes, can be reduced, making it less likely that the performance of the electrochemical module will be degraded due to poisoning of the electrodes by the catalyst poisoning substance.

[0027] If the boron content is less than the lower limit (100 ppm), the cleaning and management processes for the gas sealing material or its raw materials become complicated, which may impair productivity.On the other hand, if the boron content is more than the upper limit (2000 ppm), boron volatilized from the gas sealing material accumulates and reacts in the electrodes, causing a decrease in electrode activity and a decrease in the power generation or electrolysis performance of the electrochemical module.

[0028] A further characteristic feature of the electrochemical module according to the present invention is that the content of the fibrous particles in the gas sealing material is 50 wt % or less.

[0029] According to this configuration, the second gas is less likely to permeate the gas seal material, and the gas seal material can maintain good gas sealing properties.

[0030] Since highly linear communicating holes are likely to be formed around the fibrous particles, if the content of the fibrous particles is greater than the above upper limit (50 wt%), gas will be more likely to permeate the gas sealing material, and the gas sealing properties of the gas sealing material may be reduced.

[0031] A further characteristic feature of the electrochemical module according to the present invention is that the fibrous particles contain at least one of glass fiber and rock wool.

[0032] According to this configuration, the gas sealing material can be made of general-purpose fibrous particles.

[0033] A further characteristic feature of the electrochemical module according to the present invention is that the silicon-based compound includes at least one of vermiculite, wollastonite, and crystalline silica.

[0034] According to this configuration, when the silicon-based compound is vermiculite, wollastonite, or crystalline silica, these substances undergo little weight loss even when exposed to high temperatures of 700°C or higher and are chemically stable, so the gas sealing material is likely to retain its shape even when exposed to high temperatures for a long period of time.

[0035] A further characteristic feature of the electrochemical module according to the present invention is that the gas seal structure is configured such that the gas seal material is disposed in the gas seal portion in a state where it is compressed by 5 to 20% in the thickness direction.

[0036] According to this configuration, the restoring force generated when the compressed gas sealing material tries to return to its original thickness hardly forms any gaps at the interface between the gas sealing material and the sealing surface, so that the gas sealing performance of the gas sealing material (gas sealing structure) can be maintained well, and furthermore, there is no need to excessively increase the load required to exhibit the gas sealing performance.

[0037] If the ratio is smaller than the lower limit (5%), many voids will remain at the interface between the gas sealing material and the sealing surface, which may reduce the gas sealing performance of the gas sealing material (gas seal structure). On the other hand, if the ratio is larger than the upper limit (20%), the load required to achieve the gas sealing performance will become excessively large, requiring the application of a heavy load through complicated processes such as bolt tightening, and further requiring the use of materials and dimensions for the members of the surrounding structure that will not deform under the heavy load.

[0038] A further characteristic feature of the electrochemical module according to the present invention is that the gas seal portions are disposed on the four sides of the plate-like support body.

[0039] According to this configuration, the gap between adjacent electrochemical elements can be blocked, thereby preventing the second gas from flowing between the adjacent electrochemical elements.

[0040] A further characteristic feature of the electrochemical module according to the present invention is that the electrolyte in the electrolyte layer is a solid oxide.

[0041] According to this configuration, the electrochemical module can be a solid oxide fuel cell (SOFC).

[0042] A characteristic configuration of the energy system according to the present invention is that it includes the electrochemical module described above.

[0043] According to this configuration, it is possible to provide an energy system that can improve the efficiency of converting electrical energy into chemical energy such as fuel. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a cross-sectional view of an electrochemical module. [Figure 2] FIG. 2 is a top view of an electrochemical module. [Figure 3]FIG. 2 is a side view of an electrochemical module. [Figure 4] FIG. 1 is a schematic diagram of an electrochemical module. [Figure 5] FIG. 1 is a schematic diagram of an electrochemical device. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. [Figure 7] FIG. 7 is a view taken along line VII-VII in FIG. 5. [Figure 8] 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 5. [Figure 9] 9 is a cross-sectional view taken along line IX-IX in FIG. 5. [Figure 10] XX cross-sectional view of FIG. 5. [Figure 11] 10 is a cross-sectional view taken along the line XI-XI in FIG. 5. [Figure 12] 12 is a cross-sectional view taken along the line XII-XII in FIG. 5. [Figure 13] 13 is a cross-sectional view taken along the line XIII-XIII in FIG. 5. [Figure 14] FIG. 2 is an enlarged view of a main part of an electrochemical reaction section. [Figure 15] FIG. 2 is an exploded perspective view showing an electrochemical element laminate and a current collector. [Figure 16] FIG. 1 is a schematic diagram of an energy system. [Figure 17] FIG. 1 is a schematic diagram of another energy system. [Figure 18] 1 is a graph showing the results of a compression test in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0045] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 15, the electrochemical module M of the present invention comprises a stack S in which a plurality of electrochemical elements A, each of which has an electrolyte layer 32 and an electrode layer 31 and a counter electrode layer 33 disposed on either side of the electrolyte layer 32, are stacked in a predetermined stacking direction via annular seals 42, 52 for passing a first gas, which is one of a reducing component gas and an oxidizing component gas, along a plate-like support 10, and a container 200 in which the stack S is housed, the container 200 including a first sandwiching body 201 and a second sandwiching body 203, the first sandwiching body 201 and the second sandwiching body 203 being disposed so as to apply a predetermined clamping pressure to the stacking body S.

[0046] Furthermore, the electrochemical module M includes a gas seal section 300 for sealing a second gas different from the first gas at at least two opposing sides of the four sides of the plate-like support 10 of each of the electrochemical element A and another electrochemical element A adjacent to the electrochemical element A in either the up-down or down-stack direction, and the gas seal section 300 has a gas seal structure GS to which the clamping pressure of the first holding body 201 and the second holding body 203 is applied, and the gas seal section 300 contains fibrous particles and a silicon-based compound and has a density of 0.50 to 1.0 g / cm. 3 and the gas seal material 301 has a ratio of (load required for 20% compression) / (load required for 15% compression) in the range of 50-400.

[0047] As shown in Fig. 1, the electrochemical module M includes a stack (hereinafter referred to as the electrochemical element stack) S and a roughly rectangular parallelepiped container (housing, first holding body, second holding body) 200 that houses the electrochemical element stack S. The electrochemical element A (Fig. 4) is an element that generates electricity, and is formed in a plate shape extending from the front to the back of the paper in the cross-sectional view of Fig. 1. The electrochemical element stack S is configured by stacking a plurality of flat electrochemical elements A in the vertical stacking direction in the cross-sectional view of Fig. 1. In this embodiment, a solid oxide fuel cell (SOFC) in which the electrolyte in the electrolyte layer 32 is a solid oxide will be described as an example of the electrochemical element A.

[0048] The overall configuration of the electrochemical module M will be described in detail later.

[0049] The electrochemical module M of the present invention includes an electrochemical element A and another electrochemical element A adjacent to the electrochemical element A in either the up or down stacking direction, and is provided with a gas seal section 300 that seals a second gas different from the first gas on at least two opposing sides of the four sides of the plate-like support 10 of each electrochemical element A, and the gas seal section 300 has a gas seal structure GS that is affected by the clamping pressure of the first clamping body 201 and the second clamping body 203.

[0050] The electrochemical module M includes an electrochemical element stack S in which a plurality of electrochemical elements A are stacked, and the electrochemical element stack S can be housed inside the container 200 while being pressed and clamped by a first clamping body 201 and a second clamping body 203. By pressing and clamping the electrochemical element stack S between the two clamping bodies 201, 203 in this manner, members provided between adjacent electrochemical elements A can be arranged so as to be in close contact with both electrochemical elements A.

[0051] According to this configuration, an electrochemical element A and another electrochemical element A adjacent to the electrochemical element A in either the up or down stacking direction are provided with gas seal parts 300 for sealing in the second gas on at least two opposing sides of the four sides of the plate-like support, so that the gas seal parts 300 can be disposed on the periphery of the plate-like support 10 between both electrochemical elements A so as to be in close contact with both electrochemical elements A. In other words, the gas seal parts 300 can provide gas sealing properties against the second gas between adjacent electrochemical elements A.

[0052] The gas seal parts 300 are disposed on at least two opposing sides of the four sides of the plate-like support 10. For example, when the gas seal parts 300 are disposed on two opposing sides, the two sides on which the gas seal parts 300 are disposed can be provided with gas sealing properties against a second gas different from the first gas. In this case, the second gas can be circulated between adjacent electrochemical elements A in a direction substantially parallel to the direction in which the gas seal parts 300 are disposed (flow parts A2: described below).

[0053] Furthermore, since the electrochemical element stack S is pressed and sandwiched between the two sandwiching bodies 201, 203, the gas seal portion 300 has a gas seal structure GS that is affected by the clamping pressure of these sandwiching bodies 201, 203. As a result, the gas seal structure GS can be configured to compress the gas seal portion 300 at the peripheral edge of the plate-like support body 10.

[0054] The gas seal portion 300 contains fibrous particles and a silicon-based compound, and has a density of 0.50 to 1.0 g / cm 3 and the gas seal material 301 has a ratio of (load required for 20% compression) / (load required for 15% compression) in the range of 50-400.

[0055] The fibrous particles and silicon-based compounds can be chemically stable materials, which makes it difficult for cracks to occur inside the electrochemical module M, and allows the gas seal portion 300 (gas seal material 301) to be disposed in a chemically stable state.

[0056] The density is, for example, 0.50 to 1.0 g / cm 3 , preferably 0.60 to 0.95 g / cm 3 , more preferably 0.70 to 0.9 g / cm 3 In this embodiment, the density can be set to 0.50 to 1.0 g / cm 3 The case where

[0057] If the density is within the above range, the second gas is less likely to pass through the gas sealing material 301, and when the gas sealing material 301 comes into contact with the sealing surface (the surface of the peripheral portion of the plate-shaped support body 10), it deforms and can make good contact with the sealing surface, thereby providing good gas sealing properties against the second gas.

[0058] The density is the above lower limit (0.50 g / cm 3 ), the second gas will easily permeate the gas sealing material 301, and the gas sealing performance of the gas sealing material 301 may be significantly impaired. 3 ), if there are locally thick areas in the gas sealing material 301, only those thick areas will come into contact with the sealing surface (the surface of the peripheral edge of the plate-shaped support body 10), causing the gas sealing material 301 to not deform sufficiently, and areas other than those thick areas will not come into contact with the sealing surface, which could result in a decrease in gas sealing performance.

[0059] The ratio of (load required for 20% compression) / (load required for 15% compression) can be, for example, 50 to 400, preferably 60 to 300, and more preferably 70 to 200. In this embodiment, a case where the ratio is 50 to 400 will be described.

[0060] If the ratio of (load required for 20% compression) / (load required for 15% compression) is in the range of 50 to 400, when the gas seal material 301 is placed in the gas seal portion 300 to form the gas seal structure GS, a leak path for the second gas is unlikely to occur in the gas seal portion 300, and the load required to form the gas seal structure GS is unlikely to become large.

[0061] If the value is smaller than the above lower limit (50), when the gas seal material 301 is disposed in the gas seal portion 300 to form the gas seal structure GS, a leak path for the second gas is likely to occur in the gas seal portion 300, and there is a risk that the gas sealing property of the gas seal material 301 (gas seal structure GS) will be impaired. On the other hand, if the value is larger than the above upper limit (400), the load required to form the gas seal structure GS will increase, requiring a heavy load application process such as bolt tightening. In addition, the load that should be distributed to the cell and interconnector joints, etc. will be consumed by the gas seal material 301, increasing the resistance value and posing a risk of electrochemical performance degradation.

[0062] The gas seal parts 300 may be disposed on at least two opposing sides of the peripheral edge of the plate-shaped support body 10. For example, the gas seal parts 300 may be disposed on two opposing sides of the peripheral edge of the plate-shaped support body 10, or the gas seal parts 300 may be disposed on all four sides of the peripheral edge of the plate-shaped support body 10.

[0063] When the gas seal parts 300 are disposed on two opposing sides of the peripheral edge of the plate-like support 10, the second gas can be circulated by disposing a pair of gas seal parts 300 facing each other in a direction substantially parallel to the flow direction of the second gas between adjacent electrochemical elements A. In this case, the two sides on which the gas seal parts 300 are disposed can be provided with gas sealing properties against the second gas.

[0064] When the gas seal portions 300 are disposed on the four sides of the peripheral edge of the plate-like support 10, they can be configured to block the gaps between adjacent electrochemical elements A. This makes it possible to configure the flow portion A2 so that the second gas does not flow between adjacent electrochemical elements A. The electrochemical elements A through which the second gas does not flow become dummy electrochemical elements.

[0065] In this embodiment, the electrochemical element stack S will be described as having 17 layers of electrochemical elements A stacked in the vertical stacking direction in the cross-sectional view of Fig. 4. For simplicity, Fig. 4 shows five layers of electrochemical elements A stacked together. Fig. 4 also shows a case where four gas seal portions 300 (gas seal structures GS) are arranged. In Fig. 4, the number of electrochemical elements A and the number of gas seal portions 300 (gas seal structures GS) provided in the electrochemical element stack S are merely examples and are not limited to the above numbers.

[0066] In the gas seal structure shown in Fig. 15, the upper gas seal structure GS1 shows a case where gas seal portions 300 are arranged on four sides of the peripheral portion of the plate-shaped support body 10. On the other hand, in the gas seal structure shown in Fig. 15, the lower gas seal structure GS2 shows a case where gas seal portions 300 are arranged on two opposing sides of the peripheral portion of the plate-shaped support body 10. In Fig. 15, the numbers of the above-mentioned gas seal structures GS1 (gas seal portions 300 arranged on four sides of the plate-shaped support body 10) and GS2 (gas seal portions 300 arranged on two sides of the plate-shaped support body 10) are merely examples and are not limited to the above numbers.

[0067] The boron content in the gas sealing material 301 can be, for example, 100 to 2000 ppm (0.01 to 0.2 wt %), preferably 130 to 2000 ppm, and more preferably 150 to 1000 ppm. In this embodiment, a case where the boron content in the gas sealing material 301 is 100 to 2000 ppm will be described.

[0068] By setting the boron content within the above range as in this configuration, the content of boron, which is a catalyst poisoning substance that reduces the catalytic activity of the electrodes, can be reduced, making it less likely that the performance of the SOFC will be degraded due to poisoning of the electrodes by the catalyst poisoning substance.

[0069] If the boron content is less than the above lower limit (100 ppm), the cleaning process and management process for the gas sealing material 301 or the raw materials for the gas sealing material 301 become complicated, which may impair productivity. On the other hand, if the boron content is more than the above upper limit (2000 ppm), boron volatilized from the gas sealing material 301 accumulates and reacts in the electrodes, causing a decrease in electrode activity and a decrease in the power generation or electrolysis performance of the electrochemical module.

[0070] The content of fibrous particles in the gas sealing material 301 can be, for example, 50 wt% or less, preferably 40 wt% or less, and more preferably 30 wt% or less. In this embodiment, a case where the content of fibrous particles in the gas sealing material 301 is 50 wt% or less will be described.

[0071] If the content of fibrous particles is set to 50 wt % or less as in this configuration, the second gas is less likely to permeate the gas sealing material 301, and the gas sealing material 301 can maintain good gas sealing properties.

[0072] Since highly linear communicating holes are likely to form around the fibrous particles, if the content of the fibrous particles is greater than the above upper limit (50 wt%), gas will be more likely to permeate the gas sealing material 301, and the gas sealing properties of the gas sealing material 301 may be reduced.

[0073] The lower limit of the content of fibrous particles is preferably set to, for example, 1 wt %. If the content of fibrous particles is less than the lower limit (1 wt %), the physical strength of the gas sealing material 301 will be reduced, and cracks may occur during the assembly process, making it more likely that gas leaks will occur.

[0074] The fibrous particles may include, but are not limited to, glass fiber, rock wool, alumina fiber, etc. In this embodiment, a case will be described in which the fibrous particles include at least one of glass fiber and rock wool.

[0075] If the fibrous particles contain at least one of glass fiber and rock wool as in this configuration, the gas seal material 301 can be made of general-purpose fibrous particles.

[0076] By including a chemically stable silicon-based compound as in this configuration, the shape of the gas sealing material 301 can be easily maintained.

[0077] The silicon-based compound may include, but is not limited to, vermiculite, wollastonite, crystalline silica, etc. In this embodiment, the silicon-based compound includes at least one of vermiculite, wollastonite, and crystalline silica.

[0078] When the silicon-based compound is vermiculite, wollastonite, or crystalline silica, these substances lose little weight even when exposed to high temperatures of 700°C or higher, and are chemically stable, so the shape of the gas sealing material 301 is likely to be maintained even when exposed to high temperatures for a long period of time.

[0079] The gas seal structure GS may be configured such that the gas seal material 301 is compressed in the thickness direction by a predetermined ratio and disposed in the gas seal portion 300. The predetermined ratio may be, for example, 5 to 20%.

[0080] If the gas seal material 301 is arranged in the gas seal portion 300 in a state compressed by 5 to 20% in the thickness direction, as in the gas seal structure GS of this configuration, the restoring force of the compressed gas seal material 301 as it tries to return to its original thickness will cause almost no voids to be formed at the interface between the gas seal material 301 and the sealing surface, so that the gas sealability of the gas seal material 301 (gas seal structure GS) can be maintained well, and furthermore, there is no need to excessively increase the load required to exhibit the gas sealability.

[0081] If the predetermined ratio is smaller than the lower limit (5%), many voids will remain at the interface between the gas sealing material 301 and the sealing surface, which may reduce the gas sealing performance of the gas sealing material 301 (gas seal structure GS). On the other hand, if the predetermined ratio is larger than the upper limit (20%), the load required to achieve the gas sealing performance will become excessively large, requiring the application of a heavy load through complicated processes such as bolt tightening, and further requiring the use of materials and dimensions for the members of the surrounding structure that will not deform under a heavy load.

[0082] In addition to the above, the gas seal material 301 may contain known fillers (for example, inorganic fillers), binders, additives, and the like.

[0083] The gas sealing material 301 can be manufactured by mixing the above-mentioned raw materials and forming them into a sheet using a paper-making machine. The mixing ratios may be, for example, 60-70 wt% of inorganic filler (main component vermiculite), 5-15 wt% of wollastonite, 10-20 wt% of crystalline silica, 0.1-3 wt% of glass fiber, and 1-10 wt% of rock wool so that the total is 100 wt%.

[0084] The gas seal material 301 may be, for example, Vermosal Sheet S (manufactured by Nichias Corporation), Thermiculite #870 (manufactured by Flexitalic Co., Ltd.), or the like, but is not limited to these.

[0085] <Overall configuration of electrochemical module M> The following describes an electrochemical module M and an assembly method for the electrochemical module M according to an embodiment of the present invention. When describing the positional relationship of layers, for example, the electrolyte layer side as viewed from the electrode layer is referred to as "top" or "upper side," and the first plate-shaped body side is referred to as "bottom" or "lower side." Furthermore, since the same effect can be achieved in the present invention whether the electrochemical module M is installed vertically or horizontally, "top" and "bottom" can also be read as "left" and "right," respectively.

[0086] (1) Overall configuration of electrochemical module M The following describes the overall configuration of the electrochemical module M. As shown in Fig. 1, the electrochemical module M includes an electrochemical element stack (stack) S and a roughly rectangular parallelepiped container (housing, first clamp, second clamp) 200 that houses the electrochemical element stack S.

[0087] The electrochemical module M also includes a first gas supply section 61 that supplies a first gas to the electrochemical element stack S from outside the container 200, and a first gas discharge section 62 that discharges the first gas after reaction in the electrochemical element stack S.

[0088] In this embodiment, the first gas supply unit 61 includes an external pipe 61a for supplying the first gas, a connecting member 61b, and a supply pipe member 81c. The first gas exhaust unit 62 includes an external pipe 62a for exhausting the second gas, a connecting member 62b, and an exhaust pipe member 81d.

[0089] As shown in FIGS. 1 to 3, the container 200 is provided with a second gas supply unit 71, which supplies a second gas from outside the container 200 to the electrochemical element stack S. The second gas produced after the reaction in the electrochemical element stack S is discharged to the outside from a second gas discharge unit 72 provided in the container 200.

[0090] Here, the first gas is a reducing gas such as a fuel gas, and the second gas is an oxidizing gas such as air.

[0091] 1, the electrochemical module M is provided with apertured plate members 240 on both side surfaces of the electrochemical element stack S. The apertured plate members 240 are plate-shaped members that correspond to both side surfaces of the electrochemical element stack S and extend in the stacking direction of the electrochemical elements A, and are preferably made of an insulating material such as mica or alumina to prevent electrical short circuits in the electrochemical module M. The apertured plate members 240 have apertures 240a formed therein that penetrate the electrochemical element stack S in the planar direction.

[0092] Thus, the electrochemical element stack S receives a supply of fuel gas from the first gas supply unit 61, a supply of air from the second gas supply unit 71 through the openings 240a of the opening-equipped plate member 240, and generates electricity by causing an electrochemical reaction between the fuel gas and oxygen in the air. The fuel gas after the electrochemical reaction is discharged to the outside from the first gas discharge unit 62. The air after the electrochemical reaction is led to the second gas discharge unit 72 through the openings 240a of the opening-equipped plate member 240 and discharged from the second gas discharge unit 72 to the outside.

[0093] Here, aperture plate members 240 are provided adjacent to both side surfaces of the electrochemical element stack S, but this is not essential, and either one may be provided, or both may be omitted.

[0094] The electrochemical module M also includes, on the top of the electrochemical element stack S, a current collector 81 and an upper plate 230T (first holder), arranged in this order from the electrochemical element stack S toward the outside. Similarly, the electrochemical module M also includes, on the bottom of the electrochemical element stack S, a current collector 82, a first lower plate 210B, an elastic member 220B, and a second lower plate 230B (second holder), arranged in this order from the electrochemical element stack S toward the outside. This stack structure is shown in FIGS. 1 and 15.

[0095] The electrochemical element laminate S will be described in detail later.

[0096] (2) Description of components The top plate 230T, the first bottom plate 210B, the elastic member 220B, the second bottom plate 230B, and the container 200 are further described below.

[0097] Upper plate 230T, first lower plate 210B, and second lower plate 230B are insulating plate-like members, and are made of a ceramic material with high bending strength at high temperatures, such as 99 alumina.

[0098] The elastic member 220B is an elastic, plate-shaped member. In this embodiment, the elastic member 220B is a laminated spring member in which leaf springs having protrusions are laminated. Examples of materials for the elastic member 220B include austenitic stainless steel.

[0099] The upper plate 230T, together with the second lower plate 230B, receives a predetermined clamping pressure from the container 200, and sandwiches the electrochemical element stack S. Here, the clamping pressure is, for example, 1 mm 2 The pressure per unit area is the pressure per square meter.

[0100] (current collector) The electrochemical element laminate S is housed in the container 200 in a state where it is sandwiched between a pair of current collectors 81 and 82. The current collectors 81 and 82 are electrically connected to the electrochemical element laminate S (electrochemical element A).

[0101] In this embodiment, the current collector 81 includes a current collector plate 81a in contact with the electrochemical element A and a pipe member J through which the first gas flows. The pipe member J is fixed to the current collector plate 81a by welding. In more detail, the current collector 81 includes the current collector plate 81a, a tab portion 81b extending from the current collector plate 81a, a supply pipe member 81c serving as the pipe member J, and a discharge pipe member 81d serving as the pipe member J.

[0102] The current collector 82 includes a current collector plate 82a that contacts the electrochemical device A, and a tab portion 82b that extends from the current collector plate 82a.

[0103] Current collector plate 81a and current collector plate 82a are made of ferritic stainless steel and preferably have a thickness of 0.5 mm or more and 5 mm or less.

[0104] The tab portion 81b and the tab portion 82b are connected to the output portion 8, and power is taken out from the electrochemical module M.

[0105] 1 to 3, the container 200 that houses the electrochemical element laminate S is a roughly rectangular parallelepiped container. The container 200 includes a box-shaped upper lid 201 (first holding body) that is open at the bottom, and a lower lid 203 (second holding body) that is open at the top. A connecting portion 202 is provided on the end face of the upper lid 201 that faces the lower lid 203, and a connecting portion 205 is provided on the end face of the lower lid 203 that faces the upper lid 201. The upper lid 201 and the lower lid 203 are connected by, for example, welding the connecting portion 202 and the connecting portion 205, thereby forming a rectangular parallelepiped space inside.

[0106] 1, the depth of the lower lid 203 in the vertical direction (the stacking direction of the electrochemical device A) is deeper than the depth of the upper lid 201. However, the relationship between the depths is not limited to this as long as the upper lid 201 and the lower lid 203 can integrally form an internal space. For example, the depth of the upper lid 201 may be deeper than the lower lid 203.

[0107] As shown in FIGS. 1 to 3, a second gas supply part 71 and a second gas exhaust part 72 are formed on a pair of opposing side walls of the lower lid 203 at the center of the container 200 in the vertical direction.

[0108] Here, the second gas supply unit 71 and the second gas exhaust unit 72 are formed in the lower lid 203. However, the positions at which the second gas supply unit 71 and the second gas exhaust unit 72 are formed are not limited thereto, and they may be formed in any position in the container 200. The second gas supply unit 71 and the second gas exhaust unit 72 may be formed in the upper lid 201, for example.

[0109] As shown in FIGS. 1 and 2, the top lid 201 has an opening 201c that is slightly smaller than the outer edge of the top lid 201. In the cross-sectional view of FIG. 1, adjacent to the opening 201c, the inner end facing the electrochemical element laminate S branches into a first end 201a and a second end 201b. The first end 201a extends a predetermined length in a planar direction toward the inside of the container 200, and the second end 201b branches from the first end 201a and extends a predetermined length downward of the container 200. The first end 201a and the second end 201b form an angle of approximately 90° in the cross-sectional view, forming an L-shaped corner. This L-shaped corner is formed along the outer edge of the top lid 201 shown in FIG. 2, on the inner side of the outer edge. As a result, an opening 201c that is slightly smaller than the outer edge of the top cover 201 is formed in the top surface of the top cover 201 at the end of the first end 201a, as shown in FIGS.

[0110] A tubular portion 201d is formed at the first end portion 201a of the upper cover 201. The tubular member J (the supply pipe member 81c and the discharge pipe member 81d) of the current collector 81 is inserted into the tubular portion 201d.

[0111] Similar to the upper cover 201, the lower cover 203 has a first end 203a and a second end 203b that form L-shaped corners at an angle of approximately 90° in the cross-sectional view shown in Fig. 1. The end of the first end 203a forms an opening 203c that is slightly smaller than the outer edge of the lower cover 203, as shown in Fig. 1.

[0112] 1, the upper ends of a pair of opening plate members 240 and an upper plate 230T are fitted into the corners of the L shape formed by the first end 201a and the second end 201b of the upper cover 201. Specifically, the upper plate 230T, which is along the planar direction of the electrochemical element laminate S, is supported with the upper surface of its outer circumferential edge in contact with the lower surface of the first end 201a (part of the inner surface of the corner of the L shape). Furthermore, the opening plate member 240, which is along the side surface of the electrochemical element laminate S, is supported with the outer surface of its upper end in contact with the inner side surface of the second end 201b (part of the inner surface of the corner of the L shape).

[0113] Similarly, the lower ends of a pair of opening plate members 240, a first lower plate 210B, an elastic member 220B, and a second lower plate 230B are fitted into a pair of L-shaped corners facing each other in the planar direction of the lower cover 203.

[0114] The upper surface of the electrochemical element stack S is supported by the upper lid 201 via the upper plate 230T. The lower surface of the electrochemical element stack S is supported by the lower lid 203 via the first lower plate 210B, the elastic member 220B, and the second lower plate 230B.

[0115] With this configuration, the upper lid 201 and the lower lid 203 sandwich the electrochemical element stack S, the upper plate 230T, the first lower plate 210B, the elastic member 220B, the second lower plate 230B, etc. from above and below, and are connected by, for example, welding the connecting portion 202 and the connecting portion 205. During this connection, the upper lid 201 and the lower lid 203 are connected by applying a predetermined clamping pressure to the electrochemical element stack S, etc. In other words, with the upper lid 201 and the lower lid 203 connected, a predetermined clamping pressure is applied to the electrochemical element stack S, the upper plate 230T, the first lower plate 210B, the elastic member 220B, and the second lower plate 230B.

[0116] 3, an opening 203e is formed in the side surface of the lower lid 203. Therefore, a part of the side surface of the electrochemical element laminate S is exposed through the opening 203e. By forming the openings 201c, 203c, and opening 203e in the container 200, the weight of the container 200 can be reduced, and the amount of material required for the container 200 can be reduced. If there is a possibility of an electrical short circuit due to contact between the side surface of the electrochemical element laminate S and the upper lid 201 or the lower lid 203, or both, a side surface insulator 245 made of a material such as mica is installed between the electrochemical element laminate S and the side surface of the upper lid 201 or the lower lid 203.

[0117] The lower lid 203 and the upper lid 201 of the container 200 are joined together to apply a clamping pressure to the electrochemical element stack S. Examples of materials for such a container 200 include ferritic stainless steel, martensitic stainless steel, and composites of these with ceramics. These materials have a smaller thermal expansion coefficient than austenitic stainless steel, and the thermal expansion coefficient of ferritic stainless steel is about 11×10 for SUS430. -6 / ℃. In addition, the thermal expansion coefficient of martensitic stainless steel is approximately 10.4 × 10 for SUS403 and SUS420J1. -6 / ℃, and SUS410 and SUS440C are approximately 10.1 × 10 -6 / ° C. It is also preferable that the container 200 is made of a material that is highly corrosion-resistant.

[0118] The material of the electrochemical element laminate S is preferably the same as that of the container 200. In other words, the materials of the electrochemical element laminate S and the container 200 preferably have a thermal expansion coefficient similar to that of the container 200. In this case, the substrate of the electrochemical element laminate S and the container 200 thermally expand to the same extent, for example, during power generation when the electrochemical element A reaches a high temperature. Therefore, for example, by keeping the difference in thermal expansion between the substrate of the electrochemical element A and the container 200 small, it is possible to prevent damage to the electrochemical element A and leakage of the first gas and the second gas between the electrochemical element A and the container 200.

[0119] (3) Assembly method of electrochemical module M Next, a method for assembling the electrochemical module M will be described.

[0120] A plurality of electrochemical elements A are stacked to prepare an electrochemical element stack S. The configuration and manufacturing method of the electrochemical element stack S will be described later.

[0121] A container 200 for containing the electrochemical element laminate S is also prepared. The container 200 can be manufactured using, but is not limited to, a lost-wax casting method. When using the lost-wax casting method, a hollow model corresponding to the outer shape of the container 200 is manufactured using a thermoplastic material such as beeswax or rosin. This model is then covered with a refractory material such as silica sand or lime powder. The model covered with the refractory material is then heated to dissolve the thermoplastic model. This forms a cavity within the refractory material that corresponds to the model's shape, imitating the shape of the container 200. The material for the container 200 is poured into this cavity and solidified, and the refractory material is then removed. This results in the container 200 having an upper lid 201 and a lower lid 203 manufactured using the lost-wax casting method. Note that the upper lid 201 and the lower lid 203 may be manufactured separately.

[0122] Next, for example, a pair of opening-equipped plate members 240 are placed on both side surfaces of the electrochemical element stack S, and the upper plate 230T (first holding body), current collector 81, electrochemical element stack S, current collector 82, first lower plate 210B, elastic member 220B, and second lower plate 230B (second holding body) are placed in this order and housed in the lower lid 203. The lower lid 203 is covered with the upper lid 201, and the position is adjusted so that a predetermined clamping pressure is applied to the electrochemical element stack S, and the lower lid 203 and the upper lid 201 are joined by welding or the like. In this way, the electrochemical module M is assembled.

[0123] As described above, when the container 200 is manufactured using the lost wax casting method, it is possible to achieve cost reduction through thinning, precision, and mass production.

[0124] Furthermore, by forming the box-shaped container 200, in this embodiment, a manifold space for the air supplied from the second gas supply unit 71 to the electrochemical element stack S can be provided.

[0125] (4) Specific configuration of electrochemical module M Next, a specific configuration of the electrochemical module M will be described with reference to FIGS. The electrochemical element stack S of FIG. 1 is shown in detail in FIG.

[0126] As shown in Figures 1 and 4, the electrochemical module M includes a container 200 (top lid 201 and bottom lid 203) that houses an electrochemical element stack S, a first gas supply unit 61 that supplies a first gas from the outside of the container 200 to the internal flow path A1 via a supply path 4, a first gas discharge unit 62 that discharges the first gas after the reaction, a second gas supply unit 71 that supplies a second gas from the outside of the container 200 to the flow section A2, a second gas discharge unit 72 that discharges the second gas after the reaction, and an output unit 8 that obtains output associated with the electrochemical reaction in the electrochemical reaction section 3, and is provided within the container 200 with a distribution chamber 9 that distributes the second gas supplied from the second gas supply unit 71 to the flow section A2.

[0127] The distribution chamber 9 is a space located on the side of the electrochemical element stack S that supplies the second gas to the electrochemical element stack S, and the flow passage A2 is opened on the space side and communicates with the space.

[0128] The electrochemical element stack S is housed within the container 200 in a state where it is sandwiched between a pair of current collectors 81, 82, and an output section 8 is extended from these current collectors 81, 82 and is connected freely to a power supply destination outside the container 200 so as to supply power, and at least one of the current collectors 81, 82 is electrically insulated from the container 200 and is contained in the container 200 so as to keep the first gas airtight.

[0129] As a result, the electrochemical module M is supplied with fuel gas from the first gas supply unit 61 and air from the second gas supply unit 71, so that fuel gas enters as shown by the dashed arrows in Figures 1 and 4 and air enters as shown by the solid arrows.

[0130] The fuel gas (sometimes referred to as the first gas) supplied from the first gas supply unit 61 is guided to the supply path 4 through the first through-hole 41 of the uppermost electrochemical element A of the electrochemical element stack S, and flows through the supply path 4 partitioned by the first annular seal portion 42 to the internal flow paths A1 of all the electrochemical elements A. In addition, the air (sometimes referred to as the second gas) supplied from the second gas supply unit 71 temporarily flows into the distribution chamber 9, and then flows through the flow paths A2 formed between the electrochemical elements A.

[0131] Incidentally, when the second plate-like body 2 (part of the plate-like support body 10) is used as a reference, an internal flow path A1 is formed between the first plate-like body 1 and the second plate-like body 2 at the portion where the corrugated second plate-like body 2 bulges out from the first plate-like body 1 (part of the plate-like support body 10), and the corrugated second plate-like body 2 comes into contact with the electrochemical reaction section 3 of the adjacent electrochemical element A, enabling electrical connection. On the other hand, the portion where the corrugated second plate-like body 2 comes into contact with the first plate-like body 1 is electrically connected to the first plate-like body 1, and a flow section A2 is formed between the second plate-like body 2 and the electrochemical reaction section 3 of the adjacent electrochemical element A.

[0132] The internal flow path A1 is provided with a turbulence-forming element 90 that creates a turbulent flow of the fuel gas flowing through the internal flow path A1. The internal flow path A1 has a distribution section A12 and a sub-flow path A11 (see FIGS. 4, 9, etc.), and it is preferable that the turbulence-forming element 90 be provided in the sub-flow path A11.

[0133] The turbulence forming member 90 is composed of a turbulence forming portion 91 provided in at least one of the multiple sub-flow paths A11. In other words, the turbulence forming portions 91 provided in each of the sub-flow paths A11 are collectively referred to as the turbulence forming member 90. As described above, it is sufficient if at least one of the sub-flow paths A11 is provided with a turbulence forming portion 91, but it is preferable that all of the sub-flow paths A11 are provided with a turbulence forming portion 91. In the following, it is assumed that each of the sub-flow paths A11 is provided with a turbulence forming portion 91 that forms a turbulent flow in the fuel gas flowing through that sub-flow path A11.

[0134] 14 shows an electrochemical element A with a cross section including the internal flow path A1 and an electrochemical element A with a cross section including the flow section A2, arranged side by side for convenience, and the fuel gas supplied from the first gas supply section 61 reaches the distribution section A12 (see FIGS. 5, 7, and 9), spreads along the width direction of one end side through the distribution section A12, and reaches each sub-flow path A11 of the internal flow path A1 (see FIGS. 5, 7, and 9). In this case, the first gas can be distributed evenly from the distribution section A12 to the multiple sub-flow paths A11, and each electrochemical element can generate an equal electrochemical output.

[0135] The fuel gas that has entered each sub-channel A11 is then turbulently formed by the turbulence-forming members 91 (constituting the turbulence-forming body 90) and flows through each sub-channel A11. The fuel gas can then enter the electrode layer 31 and the electrolyte layer 32 via the gas flow-permitting member 1A. The fuel gas further travels through the internal channel A1 together with the electrochemically reacted fuel gas, passes through the junction A13 and the second through-hole 51, and proceeds to the discharge channel 5 formed by the second annular seal member 52, and is then discharged from the first gas discharge member 62 to the outside of the container 200 together with the electrochemically reacted fuel gas from the other electrochemical elements A.

[0136] On the other hand, air supplied from the second gas supply unit 71 enters the flow section A2 via the distribution chamber 9 and can enter the counter electrode layer 33 and the electrolyte layer 32. The air, together with the air that has undergone the electrochemical reaction, further travels through the flow section A2 along the electrochemical reaction unit 3 and is discharged to the outside of the container 200 through the second gas discharge unit 72.

[0137] The electricity generated in the electrochemical reaction section 3 in accordance with the flow of fuel gas and air is connected in series between the current collectors 81, 82 due to contact between the electrochemical reaction section 3 of the adjacent electrochemical element A and the second plate-like body 2, and the combined output is extracted from the output section 8.

[0138] The configuration of the electrochemical element laminate S will be described in detail later.

[0139] (5) Specific Configuration of Electrochemical Element Laminate S Next, a specific configuration of the electrochemical element laminate S will be described. The electrochemical element laminate S is formed by laminating a plurality of electrochemical elements A.

[0140] The electrochemical device A will be described with reference to FIGS.

[0141] (electrochemical element) As shown in FIGS. 5 to 13, the electrochemical device A includes a plate-like support 10 having an internal flow path A1 formed between the opposing surfaces of a first plate-like body 1 and a second plate-like body 2.

[0142] The plate-shaped support 10 is provided, in at least a part of the first plate-shaped body 1 and the second plate-shaped body 2 constituting the plate-shaped support 10, with a gas flow-permitting portion 1A that allows gas to pass between the internal flow path A1 on the inside of the plate-shaped support 10 and the outside, and an electrochemical reaction portion 3 that covers all or part of the gas flow-permitting portion 1A and has a membrane-like electrode layer 31, a membrane-like electrolyte layer 32, and a membrane-like counter electrode layer 33 in this order (see Figures 9 to 13).

[0143] In this embodiment, a turbulent flow forming portion 91 (constituting a turbulent flow forming body 90) is provided in the sub-flow path A11 of the internal flow path A1.

[0144] Furthermore, the plate-shaped support 10 has a first penetration portion 41 at one end which forms a supply path 4 that supplies a first gas, which is one of a reducing component gas such as a fuel gas and an oxidizing component gas such as air, to the internal flow path A1 from outside in the direction of penetration through the surface, and a second penetration portion 51 at the other end which forms a discharge path 5 that discharges the first gas that has flowed through the internal flow path A1 outward in the direction of penetration through the surface of the plate-shaped support (see Figures 5, 7, 12, and 13; it will also be understood that the supply path 4, etc. and the discharge path 5, etc. are symmetrical and have similar structures).

[0145] (Plate-shaped support) The first plate-like body 1 supports the electrochemical reaction unit 3, which includes the electrode layer 31, the electrolyte layer 32, and the counter electrode layer 33, and serves to maintain the strength of the electrochemical device A. The material for the first plate-like body 1 is preferably a material with excellent electronic conductivity, heat resistance, oxidation resistance, and corrosion resistance. For example, ferritic stainless steel, austenitic stainless steel, or a nickel-based alloy may be used. In particular, an alloy containing chromium is preferably used. In this embodiment, the first plate-shaped body 1 uses an Fe—Cr-based alloy containing 18 to 25 mass% of Cr, but particularly preferred are an Fe—Cr-based alloy containing 0.05 mass% or more of Mn, an Fe—Cr-based alloy containing 0.15 to 1.0 mass% of Ti, an Fe—Cr-based alloy containing 0.15 to 1.0 mass% of Zr, an Fe—Cr-based alloy containing Ti and Zr in a total content of 0.15 to 1.0 mass% or less, and an Fe—Cr-based alloy containing 0.10 to 1.0 mass% of Cu.

[0146] The second plate-like body 2 is superimposed on the first plate-like body 1 and integrated with it by welding the peripheral edge portion 1a to form the plate-like support body 10 (see FIGS. 6 to 13). The second plate-like body 2 may be divided into multiple pieces relative to the first plate-like body 1, or conversely, the first plate-like body 1 may be divided into multiple pieces relative to the second plate-like body 2. Furthermore, when integrating the first and second plate-like bodies, other means such as adhesion or fitting can be used instead of welding, and integration may be performed at a portion other than the peripheral edge portion 1a as long as the internal flow path can be formed separately from the outside.

[0147] The first plate-like body 1 has a gas flow-permitting portion 1A formed by a large number of through-holes 11 that penetrate from the front surface to the back surface (see FIGS. 9 to 13). The through-holes 11 can be formed in the first plate-like body 1 by laser processing, for example. The through-holes 11 have the function of allowing gas to pass from the back surface to the front surface of the first plate-like body 1. The gas flow-permitting portion 1A is preferably provided in an area of ​​the first plate-like body 1 that is smaller than the area where the electrode layer 31 is provided.

[0148] A metal oxide layer 12 (see FIG. 14 , described later) is provided on the surface of the first plate-like body 1 as a diffusion-suppressing layer. That is, the diffusion-suppressing layer is formed between the first plate-like body 1 and the electrode layer 31 (described later). The metal oxide layer 12 is provided not only on the surface exposed to the outside of the first plate-like body 1 but also on the contact surface (interface) with the electrode layer 31. It can also be provided on the inner surface of the through-hole 11. This metal oxide layer 12 can suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31. For example, if ferritic stainless steel containing chromium is used as the first plate-like body 1, the metal oxide layer 12 is mainly composed of chromium oxide. The metal oxide layer 12, which is mainly composed of chromium oxide, suppresses the diffusion of chromium atoms and the like from the first plate-like body 1 into the electrode layer 31 and the electrolyte layer 32. The thickness of the metal oxide layer 12 may be any thickness that achieves both high diffusion prevention performance and low electrical resistance.

[0149] The metal oxide layer 12 can be formed by various methods, but a method of oxidizing the surface of the first plate-like body 1 to form a metal oxide is preferably used. The metal oxide layer 12 may also be formed on the surface of the first plate-like body 1 by a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PVD method such as sputtering or PLD, or a CVD method, or by plating and oxidation treatment. Furthermore, the metal oxide layer 12 may contain a highly conductive spinel phase.

[0150] When ferritic stainless steel is used for the first plate-like body 1, its thermal expansion coefficient is similar to that of YSZ (yttria-stabilized zirconia) and GDC (gadolinium-doped ceria, also known as CGO), which are materials for the electrode layer 31 and the electrolyte layer 32. Therefore, the electrochemical element A is less susceptible to damage even when subjected to repeated low- and high-temperature cycles. This is preferable because it allows for an electrochemical element A with excellent long-term durability. The first plate-like body 1 has a plurality of through-holes 11 extending from the front surface to the back surface. For example, the through-holes 11 can be formed in the first plate-like body 1 by mechanical, chemical, or optical drilling. The through-holes 11 allow gas to pass from the back surface of the first plate-like body 1 to the front surface. Porous metal can also be used to impart gas permeability to the first plate-like body 1. For example, the first plate-like body 1 can be made of sintered metal, foam metal, or the like.

[0151] The plate-like support (first plate 1, second plate 2) 10 has an internal flow path A1 inside. The internal flow path A1 is formed between the first plate 1 and the second plate 2. The internal flow path A1 is provided with a plurality of sub-flow paths A11, A11 in a region facing the gas flow-permitting portion 1A of the first plate 1. The plurality of sub-flow paths A11, A11 are formed by processing the second plate 2 into a corrugated plate shape. The plurality of sub-flow paths A11, A11 extend from one end side to the other end side (first direction side) in a direction along the plate-like surface of the plate-like support 10, i.e., along the flow direction of the first gas. The plurality of sub-flow paths A11, A11 are also spaced apart from one another in a direction (second direction) intersecting from one end side to the other end side in a direction along the plate-like surface of the plate-like support 10.

[0152] The second plate-like body 2 has a corrugated front and back surfaces, and the surface opposite to the surface defining the internal flow path A1 is electrically connected to the electrochemical reaction section 3 of the adjacent electrochemical element A. A passage formed in the vicinity of the portion where the corrugated second plate-like body 2 contacts the first plate-like body 1 functions as a flow passage portion A2.

[0153] More specifically, a plurality of sub-flow passages A11 are provided in parallel along the long sides of the rectangular plate-like support 10, constituting an internal flow passage A1 extending from the supply passage 4 at one end to the discharge passage 5 at the other end. The connection between the first through-hole 41 and the internal flow passage A1 bulges downward from the contact portion with the first plate-like body 1 and includes a distribution section A12 that distributes the first gas supplied from the first through-hole 41 to each of the sub-flow passages A11 (see FIG. 5). The connection between the second through-hole 51 and the internal flow passage A1 bulges downward from the contact portion with the first plate-like body 1 and includes a confluence section A13 that collects the first gas that has flowed through each of the sub-flow passages A11 and leads it to the second through-hole 51 (see FIGS. 5, 7, 8, 10 to 13; it will be understood that the supply passages 4 and the discharge passages 5 are symmetrical and have the same structure). Furthermore, the material of the second plate-like body 2 is preferably a heat-resistant metal, and it is even more preferable if it is the same material as the first plate-like body 1 from the standpoint of reducing the thermal expansion difference with the first plate-like body 1 and ensuring the reliability of joining such as welding.

[0154] (turbulence forming body) In this embodiment, the turbulence forming member 90 is provided in the internal flow path A1, as shown in Fig. 4 and Fig. 9 to Fig. 14. The turbulence forming member 90 is formed by a turbulence forming section 91 provided in the sub-flow path A11 of the internal flow path A1. The turbulence forming section 91 forms a turbulent flow in the first gas flowing through the sub-flow path A11.

[0155] Here, the turbulent flow state in this embodiment refers to a state in which the flow of the fluid in the channel is disturbed and not parallel to the inner wall of the channel. In the turbulent flow state, at least a part of the fluid is in a swirling state. On the other hand, the laminar flow state differs from the turbulent flow state in that the flow of the fluid in the channel is parallel to the inner wall of the channel and has generally regular streamlines.

[0156] The flow state in a channel can also be expressed by the Reynolds number; a high Reynolds number indicates turbulent flow, and a low Reynolds number indicates laminar flow. The Reynolds number (Re) is defined by the following formula: Re=D×u×ρ / μ where D is the flow path diameter (m), u is the average flow velocity of the fluid (m / sec), and ρ is the density of the fluid (kg / m 3 ), μ is the viscosity of the fluid (kg / (m·sec)).

[0157] Considering that the fluid is a reducing component gas such as fuel gas or an oxidizing component gas such as air, when the gas is in a turbulent state, Re is approximately Re>2800, but it is difficult to consistently exceed this value when attempting to achieve a compact design because the flow path diameter D becomes small.

[0158] As shown in FIGS. 9 to 14, the turbulent flow forming portion 91 is provided adjacent to the lower surface of the gas flow allowing portion 1A in the secondary flow passage A11. However, the arrangement position of the turbulent flow forming portion 91 is not limited thereto as long as the first gas flowing through the secondary flow passage A11 can be made turbulent while flowing along the direction of extension of the secondary flow passage A11. For example, the turbulent flow forming portion 91 may be provided along the upper surface of the second plate-like body 2 facing the secondary flow passage A11. Alternatively, the turbulent flow forming portion 91 may be provided in the center between the lower surface of the gas flow allowing portion 1A and the upper surface of the second plate-like body 2 facing the secondary flow passage A11. Alternatively, the turbulent flow forming portion 91 may be provided so as to fill the secondary flow passage A11, as long as the first gas can flow along the direction of extension of the secondary flow passage A11.

[0159] The turbulent flow forming portion 91 is not limited to this, but may be a mesh body provided in the sub-passage A11 along the plane of the first plate-like body 1, as shown in Figs. 9 to 14. The first gas can be made to flow turbulently by passing through the mesh body. The mesh body is configured not only to make the first gas turbulent, but also to allow the first gas to flow along the sub-passage A11.

[0160] Examples of mesh-like bodies include metal mesh, expanded metal, porous metal (metal foam), metal felt, punched metal, and 3D fabric. Expanded metal is processed by cutting and stretching a flat metal plate to have, for example, a diamond-shaped mesh. Porous metal is a metal with air bubbles that form a mesh and a relatively low bulk density. Metal felt is formed by stacking and sintering metal fibers, and is processed to have a mesh between the fibers. Punched metal is processed into a mesh-like shape by punching holes in a metal plate. 3D fabric is processed to have a mesh, for example, by using a pair of flat metal plates with meshed meshes and a metal woven in a wave-like pattern between them. The shape of the mesh body is not particularly limited as long as it can create a turbulent flow of the first gas. The mesh body may be, for example, a flat plate. The flat mesh body can be arranged along the flat plate-like support 10.

[0161] The turbulent flow forming portion 91 may be, but is not limited to, granular material provided in the sub-channel A11 as shown in Fig. 1. Collision of the first gas with the granular material can cause the first gas to enter a turbulent state. The granular material is arranged regularly or irregularly in the sub-channel A11. The granular material is of a size that can be inserted into the sub-channel A11 and that allows the first gas to flow along the direction in which the sub-channel A11 extends. The granular material may be filled in the sub-channel A11 or fixed to the upper surface of the second plate-like body 2.

[0162] The turbulence generating section 91, which is formed from a mesh or granular material, may be made of austenitic stainless steel such as SUS316 or SUS304, ferritic stainless steel such as SUS430, or a nichrome heat-resistant alloy. The material of the turbulence generating section 91 may be the same as or be the same as the material of the plate-like support 10. Furthermore, when formed from a flat plate, the material is not limited to metal, and may be a conductive inorganic material such as conductive glass. When formed from granular material, the material may be non-conductive material such as ceramic, in addition to metals and conductive materials.

[0163] Furthermore, the turbulence generating portion 91 constituting the turbulence generating member 90 can be made of a material with excellent electronic conductivity, heat resistance, oxidation resistance, and corrosion resistance. Examples of suitable materials include ferritic stainless steel, austenitic stainless steel, and nickel-based alloys. In particular, alloys containing chromium are preferred. In this embodiment, the first plate-shaped member 1 is made of an Fe-Cr alloy containing 18 to 25% by mass of Cr. However, particularly preferred alloys include an Fe-Cr alloy containing 0.05% by mass or more of Mn, an Fe-Cr alloy containing 0.15 to 1.0% by mass of Ti, an Fe-Cr alloy containing 0.15 to 1.0% by mass of Zr, an Fe-Cr alloy containing Ti and Zr with a total content of Ti and Zr of 0.15 to 1.0% by mass, and an Fe-Cr alloy containing 0.10 to 1.0% by mass of Cu.

[0164] According to the above-described characteristic configuration, a first gas flows through the sub-channel A11 between the first plate-like body 1 and the second plate-like body 2. The sub-channel A11 is provided with a turbulence-forming portion 91 that creates a turbulent flow of the first gas, making the first gas prone to turbulence within the sub-channel A11. In a turbulent state, the fluid flows through the channel in a swirling state, at least in part. Therefore, the turbulent fluid flows primarily along the channel direction, but also tends to flow in a direction different from the channel direction. Therefore, the first gas flows through the sub-channel A11 along the plane of the first plate-like body 1 and the plane of the second plate-like body 2 that form the sub-channel A11, and easily permeates the gas flow-permitting portion 1A formed on the first plate-like body 1 from the sub-channel A11 to the outside. This improves the efficiency of supplying the first gas to the electrochemical reaction portion 3 formed on the outer surface of the plate-like support 10, promoting the electrochemical reaction in the electrochemical reaction portion 3 and improving power generation efficiency.

[0165] In particular, as the electrochemical element A becomes smaller, the gap between the first plate-like body 1 and the second plate-like body 2 that form the sub-channel A11 narrows and becomes flatter, and the first gas may flow in a laminar state along the plane of the plate-like support 10. However, the presence of the turbulence forming portion 91 makes the first gas more likely to flow in a turbulent state. Furthermore, when the power generation output of the electrochemical element A including the electrochemical reaction portion 3 is reduced, the amount of the first gas supplied to the sub-channel A11 is adjusted to be smaller. In this way, when the amount of the first gas flowing through the sub-channel A11 is small, the first gas may flow in a laminar state along the plane of the plate-like support 10. However, the presence of the turbulence forming portion 91 makes the first gas more likely to flow in a turbulent state. Therefore, the efficiency with which the first gas is supplied from the sub-flow passage A11 to the electrochemical reaction section 3 via the gas flow permitting section 1A is improved.

[0166] (Electrochemical reaction section)

[0167] (electrode layer) As shown in FIGS. 9 to 14, the electrode layer 31 can be provided as a thin layer on the front surface of the first plate-like body 1 in an area larger than the area where the through holes 11 are provided. When the electrode layer 31 is a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably 5 μm to 50 μm. Such a thickness makes it possible to reduce the amount of expensive electrode layer material used, thereby reducing costs, while ensuring sufficient electrode performance. The entire area where the through holes 11 are provided is covered with the electrode layer 31. In other words, the through holes 11 are formed inside the area of ​​the first plate-like body 1 where the electrode layer 31 is formed. In other words, all of the through holes 11 are provided facing the electrode layer 31.

[0168] The electrode layer 31 has a plurality of pores inside and on the surface thereof to provide gas permeability.

[0169] That is, the electrode layer 31 is formed as a porous layer. The electrode layer 31 is formed, for example, so that its density is 30% or more and less than 80%. The size of the pores can be appropriately selected so that the electrochemical reaction proceeds smoothly. Note that the density is the proportion of the space occupied by the material constituting the layer, and can be expressed as (1 - porosity), and is equivalent to the relative density.

[0170] The material of the electrode layer 31 may be a composite material such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO2, or Cu-CeO2. In these examples, GDC, YSZ, and CeO2 can be called aggregates of the composite material. The electrode layer 31 is preferably formed by a low-temperature firing method (e.g., a wet method using firing at a low temperature without firing at a high temperature above 1100°C), a spray coating method (thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, cold spray, etc.), a PVD method (sputtering, pulsed laser deposition, etc.), a CVD method, etc. These processes, which can be used in a low-temperature range, can produce a good electrode layer 31 without firing at a high temperature above 1100°C, for example. Therefore, this is preferable because it prevents damage to the first plate-like body 1 and suppresses interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, resulting in an electrochemical device A with excellent durability. Furthermore, using a low-temperature firing method is even more preferable because it facilitates handling of raw materials.

[0171] (middle class) The intermediate layer 34 can be formed as a thin layer on the electrode layer 31, covering the electrode layer 31. When the intermediate layer 34 is a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably about 2 μm to 50 μm, and more preferably about 4 μm to 25 μm. This thickness reduces the amount of expensive material used for the intermediate layer 34, thereby reducing costs, while ensuring sufficient performance. Examples of materials that can be used for the intermediate layer 34 include YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), and SDC (samarium-doped ceria). Ceria-based ceramics are particularly preferred.

[0172] The intermediate layer 34 is preferably formed by a low-temperature firing method (e.g., a wet method using firing at a low temperature without firing at a high temperature above 1100°C), a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PVD method (such as sputtering or pulsed laser deposition), or a CVD method. These low-temperature deposition processes can be used to obtain the intermediate layer 34 without firing at a high temperature above 1100°C. This prevents interdiffusion of elements between the first plate-like body 1 and the electrode layer 31 without damaging the first plate-like body 1, resulting in an electrochemical device A with excellent durability. Furthermore, a low-temperature firing method is more preferable because it facilitates handling of raw materials.

[0173] The intermediate layer 34 preferably has oxygen ion (oxide ion) conductivity. Furthermore, it is more preferable that the intermediate layer 34 has mixed conductivity of oxygen ions (oxide ions) and electrons. The intermediate layer 34 having these properties is suitable for application to the electrochemical device A.

[0174] (electrolyte layer) As shown in FIGS. 9 to 14, the electrolyte layer 32 is formed as a thin layer on the intermediate layer 34, covering the electrode layer 31 and the intermediate layer 34. Alternatively, the electrolyte layer 32 may be formed as a thin film having a thickness of 10 μm or less. Specifically, the electrolyte layer 32 is provided over (straddles) the intermediate layer 34 and the first plate-like body 1. By configuring the electrolyte layer 32 in this way and joining the electrolyte layer 32 to the first plate-like body 1, the electrochemical element as a whole can have excellent robustness.

[0175] 9, the electrolyte layer 32 is provided on the front surface of the first plate-like body 1 in an area larger than the area in which the through-holes 11 are provided. In other words, the through-holes 11 are formed inside the area in the first plate-like body 1 in which the electrolyte layer 32 is formed.

[0176] Furthermore, gas leakage from the electrode layer 31 and the intermediate layer (not shown) can be suppressed around the electrolyte layer 32. Specifically, when the electrochemical element A is used as a component of an SOFC, gas is supplied to the electrode layer 31 from the back side of the first plate 1 through the through-holes 11 during operation of the SOFC. Gas leakage can be suppressed in the area where the electrolyte layer 32 contacts the first plate 1 without providing a separate member such as a gasket. Note that, although the electrolyte layer 32 completely covers the periphery of the electrode layer 31 in this embodiment, a configuration in which the electrolyte layer 32 is provided on top of the electrode layer 31 and the intermediate layer 34 and a gasket or the like is provided around the periphery may also be adopted.

[0177] The electrolyte layer 32 can be made of oxygen ion-conducting electrolyte materials such as YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), SDC (samarium-doped ceria), or LSGM (strontium-magnesium-doped lanthanum gallate), or hydrogen ion-conducting electrolyte materials such as perovskite-type oxides. Zirconia-based ceramics are particularly suitable. Using zirconia-based ceramics for the electrolyte layer 32 can increase the operating temperature of an SOFC using electrochemical element A compared to ceria-based ceramics and various hydrogen ion-conducting materials. For example, when electrochemical element A is used in an SOFC, if a material such as YSZ that can exhibit high electrolyte performance even at high temperatures of approximately 650°C or higher is used as the material for electrolyte layer 32, and if a hydrocarbon-based raw fuel such as city gas or LPG is used as the raw fuel for the system and the raw fuel is converted into SOFC anode gas by steam reforming or the like, a highly efficient SOFC system can be constructed in which the heat generated in the SOFC cell stack is used to reform the raw fuel gas.

[0178] The electrolyte layer 32 is preferably formed by a low-temperature firing method (e.g., a wet method using firing at a low temperature without firing at a high temperature above 1100°C), a spray coating method (thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, cold spray, etc.), a PVD method (sputtering, pulsed laser deposition, etc.), a CVD (chemical vapor deposition) method, etc. These film formation processes that can be used in a low-temperature range can produce an electrolyte layer 32 that is dense and has high airtightness and gas barrier properties without firing at a high temperature above 1100°C, for example. This can suppress damage to the first plate-like body 1 and interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, resulting in an electrochemical device A with excellent performance and durability. In particular, low-temperature firing methods and spray coating methods are preferred because they allow for low-cost devices to be produced. Furthermore, spray coating is more preferable because it is easy to obtain a dense electrolyte layer that is airtight and has high gas barrier properties in a low temperature range.

[0179] The electrolyte layer 32 is densely structured to prevent gas leakage of anode gas and cathode gas and to exhibit high ionic conductivity. The density of the electrolyte layer 32 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. When the electrolyte layer 32 is a uniform layer, the density is preferably 95% or more, and even more preferably 98% or more. Furthermore, when the electrolyte layer 32 is structured in a multi-layer structure, it is preferable that at least a portion of the layers includes a layer with a density of 98% or more (a dense electrolyte layer), and more preferably a layer with a density of 99% or more (a dense electrolyte layer). When such a dense electrolyte layer is included as part of the electrolyte layer, it is easier to form an electrolyte layer that is dense and has high airtightness and gas barrier properties, even when the electrolyte layer is structured in a multi-layer structure.

[0180] (Reaction prevention layer) The reaction prevention layer 35 can be formed as a thin layer on the electrolyte layer 32. When the layer is thin, its thickness can be, for example, about 1 μm to 100 μm, preferably about 2 μm to 50 μm, and more preferably about 3 μm to 15 μm. This thickness reduces the amount of expensive reaction prevention layer material used, thereby reducing costs and ensuring sufficient performance. The material for the reaction prevention layer can be any material that can prevent a reaction between the components of the electrolyte layer 32 and the components of the counter electrode layer 33, such as a ceria-based material. A material containing at least one element selected from the group consisting of Sm, Gd, and Y is preferably used as the material for the reaction prevention layer 35. It is preferable that the material contains at least one element selected from the group consisting of Sm, Gd, and Y, and that the total content of these elements is 1.0% by mass or more and 10% by mass or less. By introducing the reaction prevention layer 35 between the electrolyte layer 32 and the counter electrode layer 33, the reaction between the constituent materials of the counter electrode layer 33 and the electrolyte layer 32 is effectively suppressed, thereby improving the long-term stability of the performance of the electrochemical device A. The reaction prevention layer 35 is preferably formed using a method that allows it to be formed at a processing temperature of 1100°C or less, because this prevents damage to the first plate-like body 1 and also suppresses interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, resulting in an electrochemical device A with excellent performance and durability. For example, the reaction prevention layer 35 can be formed by a low-temperature firing method (e.g., a wet method that uses a firing process at a low temperature that does not involve firing at a high temperature above 1100°C), a spray coating method (such as a thermal spraying method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method. In particular, low-temperature firing or spray coating is preferred because it allows for low-cost elements to be realized. Furthermore, low-temperature firing is even more preferred because it allows for easy handling of raw materials.

[0181] (Counter electrode layer) As shown in FIGS. 9 to 14, the counter electrode layer 33 can be formed as a thin layer on the electrolyte layer 32 or the reaction prevention layer 35. When the counter electrode layer 33 is formed as a thin layer, its thickness can be, for example, approximately 1 μm to 100 μm, preferably 5 μm to 50 μm. This thickness reduces the amount of expensive counter electrode layer material used, thereby reducing costs, while ensuring sufficient electrode performance. Examples of materials that can be used for the counter electrode layer 33 include composite oxides such as LSCF and LSM, ceria-based oxides, and mixtures thereof. It is particularly preferable that the counter electrode layer 33 contains a perovskite-type oxide containing two or more elements selected from the group consisting of La, Sr, Sm, Mn, Co, and Fe. The counter electrode layer 33 formed using these materials functions as a cathode.

[0182] The counter electrode layer 33 is preferably formed using a method capable of forming the counter electrode layer 33 at a processing temperature of 1100°C or less, since this method can prevent damage to the first plate 1 and suppress interdiffusion of elements between the first plate 1 and the electrode layer 31, thereby achieving an electrochemical device A with excellent performance and durability. For example, a low-temperature firing method (e.g., a wet method using a firing process at a low temperature without firing at a high temperature above 1100°C), a spray coating method (thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, cold spray, etc.), a PDV method (sputtering, pulsed laser deposition, etc.), a CVD method, etc., can be used. Low-temperature firing methods and spray coating methods are particularly preferred, as they allow for low-cost devices. Furthermore, low-temperature firing methods are even more preferred, as they facilitate the handling of raw materials.

[0183] By configuring the electrochemical reaction unit 3 in this way, when the electrochemical reaction unit 3 is made to function as a fuel cell (electrochemical power generation cell), the electrochemical element A can be used as a power generation cell of a solid oxide fuel cell. For example, a fuel gas containing hydrogen as a first gas is supplied to the electrode layer 31 through the through-holes 11 from the back surface of the first plate-like body 1, and air as a second gas is supplied to the counter electrode layer 33, which is the counter electrode of the electrode layer 31, and the temperature is maintained at an operating temperature of, for example, about 700°C. Then, oxygen O2 contained in the air is converted into electrons e in the counter electrode layer 33. - reacts with oxygen ions O 2- The oxygen ions O 2- The hydrogen H2 contained in the supplied fuel gas moves through the electrolyte layer 32 to the electrode layer 31. In the electrode layer 31, the hydrogen H2 contained in the supplied fuel gas is converted into oxygen ions O 2- reacts with water H2O and electrons e - is generated. When an electrolyte material that conducts hydrogen ions is used for the electrolyte layer 32, hydrogen H2 contained in the fuel gas flowing through the electrode layer 31 is converted into electrons e - releases hydrogen ions H + The hydrogen ions H + moves through the electrolyte layer 32 to the counter electrode layer 33. At the counter electrode layer 33, oxygen O2 and hydrogen ions H + , electronic e - reacts to produce water H2O. The above reaction generates an electromotive force as an electrochemical output between the electrode layer 31 and the counter electrode layer 33. In this case, the electrode layer 31 functions as the fuel electrode (anode) of the fuel cell, and the counter electrode layer 33 functions as the air electrode (cathode).

[0184] 9 to 13, in this embodiment, the electrochemical reaction unit 3 includes an intermediate layer 34 between the electrode layer 31 and the electrolyte layer 32, as shown in FIG. 14. Furthermore, a reaction prevention layer 35 is provided between the electrolyte layer 32 and the counter electrode layer 33.

[0185] (Method of manufacturing electrochemical reaction section) Next, a description will be given of a method for manufacturing the electrochemical reaction section 3. Note that, since the intermediate layer 34 and the reaction prevention layer 35 described below are omitted in Figs. 9 to 13, the description will be made mainly with reference to Fig. 14.

[0186] (Electrode layer formation step) In the electrode layer formation step, the electrode layer 31 is formed as a thin film on an area of ​​the front surface of the first plate-like body 1 that is larger than the area where the through-holes 11 are formed. The through-holes 11 in the first plate-like body 1 can be formed by laser processing or the like. As described above, the electrode layer 31 can be formed by low-temperature firing (a wet method that performs firing at a low temperature of 1100°C or less), spray coating (thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, cold spray, or other methods), PVD (sputtering, pulsed laser deposition, or other methods), CVD, or the like. Whichever method is used, it is preferable to perform the process at a temperature of 1100°C or less to prevent deterioration of the first plate-like body 1.

[0187] When the electrode layer forming step is performed by a low-temperature firing method, the step is specifically performed as follows. First, a material powder of the electrode layer 31 is mixed with a solvent (dispersion medium) to prepare a material paste, which is then applied to the front surface of the first plate-like body 1 and fired at 800°C to 1100°C.

[0188] (Diffusion suppression layer formation step) During the firing process in the electrode layer formation step described above, a metal oxide layer 12 (diffusion-preventing layer) is formed on the surface of the first plate-like body 1. It is preferable that the firing process includes a firing process in which the firing atmosphere is set under atmospheric conditions with a low oxygen partial pressure, since this effectively suppresses interdiffusion of elements and forms a high-quality metal oxide layer 12 (diffusion-preventing layer) with low resistance. The electrode layer formation step may also include a separate diffusion-preventing layer formation step, including when a coating method is used without firing. In either case, it is desirable to perform the process at a processing temperature of 1100°C or less, which can prevent damage to the first plate-like body 1.

[0189] (Intermediate layer formation step) In the intermediate layer forming step, a thin intermediate layer 34 is formed on the electrode layer 31 so as to cover the electrode layer 31. As described above, the intermediate layer 34 can be formed by a low-temperature firing method (a wet method in which firing is performed at a low temperature of 1100°C or less), a spray coating method (such as a thermal spraying method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method. Whichever method is used, it is preferable to perform the formation at a temperature of 1100°C or less in order to prevent deterioration of the first plate-like body 1.

[0190] When the intermediate layer forming step is performed by a low-temperature firing method, the following specific example is performed.

[0191] First, a material powder for the intermediate layer 34 is mixed with a solvent (dispersion medium) to form a material paste, which is then applied to the front surface of the first plate-like body 1. The intermediate layer 34 is then compression-molded (intermediate layer smoothing step) and fired at 1100°C or less (intermediate layer firing step). The intermediate layer 34 can be rolled by, for example, CIP (Cold Isostatic Pressing), roll pressing, or RIP (Rubber Isostatic Pressing). The intermediate layer 34 is preferably fired at a temperature of 800°C or more and 1100°C or less. This is because such a temperature allows for the formation of a high-strength intermediate layer 34 while suppressing damage and deterioration of the first plate-like body 1. The intermediate layer 34 is more preferably fired at 1050°C or less, and even more preferably at 1000°C or less. This is because the lower the firing temperature of the intermediate layer 34, the more effectively the electrochemical element A can be formed while suppressing damage and deterioration of the first plate-like body 1. Furthermore, the order of the intermediate layer smoothing step and the intermediate layer firing step can be reversed.

[0192] The intermediate layer smoothing step can also be carried out by lapping, leveling, cutting and polishing the surface, or the like.

[0193] (Electrolyte layer formation step) In the electrolyte layer formation step, the electrolyte layer 32 is formed as a thin layer on the intermediate layer 34, covering the electrode layer 31 and the intermediate layer 34. Alternatively, the electrolyte layer 32 may be formed as a thin film having a thickness of 10 μm or less. As described above, the electrolyte layer 32 can be formed by a low-temperature firing method (a wet method in which firing is performed at a low temperature of 1100°C or less), a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PVD method (such as sputtering or pulsed laser deposition), or a CVD method. Whichever method is used, it is preferable to perform the formation at a temperature of 1100°C or less to prevent deterioration of the first plate-like body 1.

[0194] To form a high-quality electrolyte layer 32 that is dense, airtight, and has excellent gas barrier properties at temperatures below 1100° C., it is desirable to perform the electrolyte layer formation step by spray coating. In this case, the material for the electrolyte layer 32 is sprayed toward the intermediate layer 34 on the first plate-like body 1 to form the electrolyte layer 32.

[0195] (Reaction prevention layer formation step) In the reaction prevention layer formation step, the reaction prevention layer 35 is formed as a thin layer on the electrolyte layer 32. As described above, the reaction prevention layer 35 can be formed by a low-temperature firing method (a wet method in which firing is performed at a low temperature of 1100°C or less), a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PVD method (such as sputtering or pulsed laser deposition), or a CVD method. Whichever method is used, it is preferable to perform the process at a temperature of 1100°C or less to prevent deterioration of the first plate-like body 1. To flatten the upper surface of the reaction prevention layer 35, for example, a leveling process or a cutting / polishing process may be performed after the formation of the reaction prevention layer 35, or a press process may be performed after wet formation and before firing.

[0196] (Counter electrode layer formation step) In the counter electrode layer formation step, the counter electrode layer 33 is formed in a thin layer state on the reaction prevention layer 35. As described above, the counter electrode layer 33 can be formed by a low-temperature firing method (a wet method in which firing is performed at a low temperature of 1100°C or less), a spray coating method (such as a thermal spraying method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method. Whichever method is used, it is preferable to perform the formation at a temperature of 1100°C or less to prevent deterioration of the first plate-like body 1.

[0197] In this manner, the electrochemical reaction section 3 can be manufactured.

[0198] The electrochemical reaction unit 3 may be configured without either or both of the intermediate layer 34 and the reaction prevention layer 35. That is, the electrode layer 31 and the electrolyte layer 32 may be formed in contact with each other, or the electrolyte layer 32 and the counter electrode layer 33 may be formed in contact with each other. In this case, the intermediate layer forming step and the reaction prevention layer forming step are omitted from the above-described manufacturing method. It is also possible to add a step of forming another layer or to stack multiple layers of the same type, but in either case, it is preferable to perform the process at a temperature of 1100°C or less.

[0199] (Electrochemical element stack) 4, the electrochemical element stack S is configured by stacking a plurality of electrochemical elements A in a predetermined stacking direction. Adjacent electrochemical elements A are arranged such that the plate-like support 10 constituting one electrochemical element A (first electrochemical element A) faces the plate-like support 10 constituting the other electrochemical element A (second electrochemical element A).

[0200] For example, one electrochemical element A (first electrochemical element A) comprises a plate-like support 10 having a first plate-like body 1 and a second plate-like body 2 on which an electrochemical reaction unit 3 is arranged. Similarly, the plate-like support 10 of a second electrochemical element A adjacent to the first electrochemical element A in the downward direction (first direction) and upward direction (second direction) also comprises a plate-like support 10 having a first plate-like body 1 and a second plate-like body 2 on which an electrochemical reaction unit 3 is arranged.

[0201] The outer surface of the second plate 2 of the first electrochemical element A is electrically connected to the outer surface of the first plate 1 of the upper adjacent second electrochemical element A. In addition, a flow section A2 through which the second gas flows is formed between the outer surface of the second plate 2 of the first electrochemical element A and the outer surface of the first plate 1 of the upper adjacent second electrochemical element A along both outer surfaces.

[0202] The outer surface of the first plate 1 of the first electrochemical element A is electrically connected to the outer surface of the second plate 2 of the adjacent second electrochemical element A. A sub-channel A11 (part of the internal channel A1) through which the first gas flows is formed between the outer surface of the first plate 1 of the first electrochemical element A and the outer surface of the second plate 2 of the adjacent second electrochemical element A. To achieve electrical connection, methods that can be used include simply contacting the electrically conductive surface portions, applying surface pressure to the contact surfaces, or inserting a highly electrically conductive material between them to reduce contact resistance.

[0203] The sub-passage A11 is provided with the turbulent flow forming section 91 as described above.

[0204] A plurality of such electrochemical elements A are stacked. Specifically, the rectangular electrochemical elements are stacked in a state where the first through-hole 41 at one end and the second through-hole 51 at the other end are aligned, with the electrochemical reaction portion of each electrochemical element facing upward. A first annular seal portion 42 is interposed between each first through-hole 41, and a second annular seal portion 52 is interposed between each second through-hole 51.

[0205] The plate-shaped support 10 is provided with a first through-portion 41 at one longitudinal end of the rectangular plate-shaped support 10. The first through-portion 41 forms a supply path 4 for supplying a first gas, which is one of a reducing component gas and an oxidizing component gas, to the internal flow path A1 from the outer side in the surface penetration direction. Within the flow path A2, the first through-portions 41 formed on both outer surfaces of the plate-shaped support 10 are provided with a first annular seal portion 42 as an annular seal portion that separates the flow path A2. The first through-portion 41 and the first annular seal portion 42 form the supply path 4 for supplying the first gas to the internal flow path A1. An annular bulge portion a is provided on the surface of the first plate-shaped support 11 opposite the internal flow path A1 around the portion of the first plate-shaped support 1 that comes into contact with the first annular seal portion 42, making it easy to position the first annular seal portion 42 along the surface of the first plate-shaped support 1.

[0206] The plate-shaped support body 10 is also provided with second through-portions 51 at the other end thereof, which form an exhaust path 5 for exhausting the first gas that has flowed through the internal flow path A1 outward in the direction penetrating the surface of the plate-shaped support body 10. The second through-portions 51 are configured to allow the first gas to flow while being separated from the second gas. The second through-portions 51 are provided with second annular seal portions 52 as annular seal portions that separate the second through-portions 51 formed on both outer surfaces of the plate-shaped support body 10 from the flow-through portion A2, within the flow-through portion A2. The second through-portions 51 and the second annular seal portions 52 form an exhaust path 5 for exhausting the first gas that has flowed through the internal flow path A1.

[0207] The first annular seal portion 42 and the second annular seal portion 52 are made of an insulating material such as a ceramic material such as alumina, mica, or a metal coated with these, and function as insulating seal portions that electrically insulate adjacent electrochemical elements from each other.

[0208] As described above, adjacent electrochemical elements A are arranged such that the plate-like support 10 constituting one electrochemical element A (first electrochemical element A) faces the plate-like support 10 constituting the other electrochemical element A (second electrochemical element A). The gas seal part 300 is provided between the plate-like support 10 constituting one electrochemical element A and the plate-like support 10 constituting the other electrochemical element A.

[0209] (6) Energy systems, electrochemical devices Next, the energy system and the electrochemical device will be described with reference to FIG.

[0210] The energy system Z includes an electrochemical device 100 and a heat exchanger 190 as a waste heat utilization section that reuses heat discharged from the electrochemical device 100.

[0211] The electrochemical device 100 has an electrochemical module M, a fuel converter consisting of a desulfurizer 101 and a reformer 102, a fuel supply unit 103 that supplies fuel gas containing a reducing component to the electrochemical module M, and an inverter (an example of a power converter) 104 as an output unit 8 that extracts electricity from the electrochemical module M.

[0212] Specifically, the electrochemical device 100 includes a desulfurizer 101, a reforming water tank 105, a vaporizer 106, a reformer 102, a blower 107, a combustion unit 108, an inverter 104, a control unit 110, and an electrochemical module M.

[0213] The desulfurizer 101 removes (desulfurizes) sulfur compounds contained in hydrocarbon raw fuel such as city gas. When sulfur compounds are contained in the raw fuel, the provision of the desulfurizer 101 can suppress adverse effects of the sulfur compounds on the reformer 102 or the electrochemical device A. The vaporizer 106 generates steam from reforming water supplied from the reforming water tank 105. The reformer 102 uses the steam generated in the vaporizer 106 to steam reform the raw fuel desulfurized in the desulfurizer 101, generating a reformed gas containing hydrogen.

[0214] The electrochemical module M generates electricity by electrochemical reaction using the reformed gas supplied from the reformer 102 and the air supplied from the blower 107. The combustion section 108 mixes the reaction exhaust gas discharged from the electrochemical module M with air and combusts combustible components in the reaction exhaust gas.

[0215] The inverter 104 adjusts the output power of the electrochemical module M to the same voltage and frequency as electricity received from a commercial grid (not shown). The control unit 110 controls the operation of the electrochemical device 100 and the energy system Z.

[0216] The reformer 102 performs a reforming process on the raw fuel using the combustion heat generated by the combustion of the reaction exhaust gas in the combustion section 108 .

[0217] The raw fuel is supplied to the desulfurizer 101 through a raw fuel supply path 112 by operation of a booster pump 111. The reforming water in the reforming water tank 105 is supplied to the vaporizer 106 through a reforming water supply path 114 by operation of a reforming water pump 113. The raw fuel supply path 112 merges with the reforming water supply path 114 at a location downstream of the desulfurizer 101, and the merged reforming water and raw fuel are supplied to the vaporizer 106.

[0218] The reforming water is vaporized in the vaporizer 106 to become water vapor. The raw fuel containing water vapor produced in the vaporizer 106 is supplied to the reformer 102 through a water vapor-containing raw fuel supply path 115. The raw fuel is steam reformed in the reformer 102 to produce a reformed gas (first gas having a reducing component) mainly composed of hydrogen gas. The reformed gas produced in the reformer 102 is supplied to the electrochemical module M through a fuel supply unit 103.

[0219] The reaction exhaust gas is combusted in the combustion section 108 to become a combustion exhaust gas, which is sent from the combustion exhaust gas discharge path 116 to the heat exchanger 190. A combustion catalyst section 117 (e.g., a platinum-based catalyst) is arranged in the combustion exhaust gas discharge path 116, and reduces the carbon monoxide, hydrogen, and other reducing components contained in the combustion exhaust gas by combustion.

[0220] The heat exchanger 190 exchanges heat between the combustion exhaust gas generated by combustion in the combustion unit 108 and the supplied cold water to generate hot water. In other words, the heat exchanger 190 operates as a waste heat utilization unit that reuses the heat discharged from the electrochemical device 100.

[0221] Instead of the exhaust heat utilization section, a reaction exhaust gas utilization section may be provided that utilizes the reaction exhaust gas discharged (without being combusted) from the electrochemical module M. Also, at least a portion of the reaction exhaust gas circulating from the first gas discharge section 62 to the outside of the container 200 may be recycled by joining it with any of the locations 100, 101, 103, 106, 112, 113, and 115 in FIG. 16. The reaction exhaust gas contains residual hydrogen gas that was not used in the reaction in the electrochemical device A. In the reaction exhaust gas utilization section, the residual hydrogen gas is utilized for heat utilization by combustion or for power generation using a fuel cell or the like, thereby making effective use of energy.

[0222] Other Embodiments The configurations disclosed in the above-described embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention.

[0223] (1) In the above embodiment, the turbulence forming element 90 is provided in the internal flow path A1, more specifically, the turbulence forming section 91 is provided in the sub-flow path A11. However, the turbulence forming element 90 may be provided in the flow path A2. By providing the turbulence forming element 90 in the flow path A2, the second gas flowing through the flow path A2 can be made to be in a turbulent state, and the contact time with the electrode layer 31 can be extended.

[0224] The turbulence formation body 90 may be arranged in the following manner: the turbulence formation body 90 is provided only in the secondary flow path A11; the turbulence formation body 90 is provided only in the flow section A2; or the turbulence formation body 90 is provided in both the secondary flow path A11 and the flow section A2.

[0225] (2) In the above embodiment, the electrochemical element A is used in a solid oxide fuel cell as the electrochemical device 100, but the electrochemical element A can also be used in a solid oxide electrolysis cell, an oxygen sensor using a solid oxide, etc. Furthermore, the electrochemical element A can be used alone, not limited to being used in combination as the electrochemical element stack S or the electrochemical module M. That is, in the above embodiment, a configuration has been described that can improve the efficiency of converting chemical energy such as fuel into electrical energy. That is, in the above embodiment, the electrochemical device A and the electrochemical module M are operated as a fuel cell, and hydrogen gas is passed through the electrode layer 31, and oxygen gas is passed through the counter electrode layer 33. Then, oxygen molecules O2 are converted into electrons e - reacts with oxygen ions O 2- The oxygen ions O 2- moves through the electrolyte layer 32 to the electrode layer 31. In the electrode layer 31, hydrogen molecules H2 are converted into oxygen ions O 2- reacts with water H2O and electrons e - The above reaction generates an electromotive force between the electrode layer 31 and the counter electrode layer 33, generating electricity. On the other hand, when the electrochemical device A and the electrochemical module M are operated as an electrolysis cell, a gas containing water vapor and carbon dioxide is passed through the electrode layer 31, and a voltage is applied between the electrode layer 31 and the counter electrode layer 33. Then, electrons e - reacts with water molecules H2O and carbon dioxide molecules CO2 to produce hydrogen molecules H2, carbon monoxide CO, and oxygen ions O 2- Oxygen ions O 2- moves through the electrolyte layer 32 to the counter electrode layer 33. In the counter electrode layer 33, oxygen ions O 2- releases electrons and becomes oxygen molecules O2. Through the above reaction, water molecules H2O are electrolyzed into hydrogen H2 and oxygen O2, and when gas containing carbon dioxide molecules CO2 is circulated, it is electrolyzed into carbon monoxide CO and oxygen O2. When gas containing water vapor and carbon dioxide molecules CO2 is circulated, a fuel converter 25 (FIG. 17) can be provided to synthesize various compounds such as hydrocarbons from the hydrogen and carbon monoxide produced by the electrolysis in the electrochemical element A and electrochemical module M. The hydrocarbons produced by the fuel converter 25 can be circulated to the electrochemical element A and electrochemical module M by a fuel supply unit (not shown), or can be taken out of the system / device and used as a separate fuel or chemical raw material.

[0226] FIG. 17 shows an example of an energy system Z and an electrochemical device 100 in which the electrochemical reaction unit 3 operates as an electrolysis cell. In this system, supplied water and carbon dioxide are electrolyzed in the electrochemical reaction unit 3 to produce hydrogen, carbon monoxide, and the like. Hydrocarbons and the like are then synthesized in the fuel converter 25. Energy efficiency can be improved by configuring the heat exchanger 24 in FIG. 17 to operate as a waste heat utilization unit that exchanges heat between the reaction heat generated by the reaction in the fuel converter 25 and water to vaporize it, and the heat exchanger 23 in FIG. 17 to operate as a waste heat utilization unit that exchanges heat between the waste heat generated by the electrochemical element A and water vapor and carbon dioxide to preheat them. Furthermore, the power converter 93 supplies power to the electrochemical device A. As a result, the electrochemical device A functions as an electrolytic cell as described above. Therefore, with the above configuration, it is possible to provide the electrochemical device 100, the energy system Z, and the like that can improve the efficiency of converting electrical energy into chemical energy such as fuel.

[0227] (3) In the above embodiment, the material of the electrode layer 31 is, for example, NiO. - GDC, Ni - GDC, NiO - YSZ, Ni - YSZ, CuO - CeO2, Cu -A composite material such as CeO2 is used, and a composite oxide such as LSCF or LSM is used as the material for the counter electrode layer 33. The electrochemical element A configured in this manner can be used as a solid oxide fuel cell by supplying hydrogen gas to the electrode layer 31 to make it a fuel electrode (anode) and supplying air to the counter electrode layer 33 to make it an air electrode (cathode). This configuration can also be modified to configure the electrochemical element A so that the electrode layer 31 can be used as an air electrode and the counter electrode layer 33 can be used as a fuel electrode. That is, a composite oxide such as LSCF or LSM is used as the material for the electrode layer 31, and a composite oxide such as NiO is used as the material for the counter electrode layer 33. - GDC, Ni - GDC, NiO - YSZ, Ni - YSZ, CuO - CeO2, Cu - A composite material such as CeO2 is used. In the electrochemical element A configured in this manner, air is supplied to the electrode layer 31 to make it an air electrode, and hydrogen gas is supplied to the counter electrode layer 33 to make it a fuel electrode, so that the electrochemical element A can be used as a solid oxide fuel cell.

[0228] (4) In the above embodiment, the electrode layer 31 is disposed between the first plate 1 and the electrolyte layer 32, and the counter electrode layer 33 is disposed on the opposite side of the electrolyte layer 32 from the first plate 1. A configuration in which the electrode layer 31 and the counter electrode layer 33 are disposed in reverse is also possible. That is, a configuration in which the counter electrode layer 33 is disposed between the first plate 1 and the electrolyte layer 32, and the electrode layer 31 is disposed on the opposite side of the electrolyte layer 32 from the first plate 1 is also possible. In this case, the supply of gas to the electrochemical device A must also be changed.

[0229] That is, various configurations can be adopted for the order of the electrode layer 31 and the counter electrode layer 33 and whether the first gas or the second gas is one or the other of the reducing component gas and the oxidizing component gas, as long as the first gas and the second gas are supplied to the electrode layer 31 and the counter electrode layer 33 in a manner that allows them to react appropriately.

[0230] (5) In the above embodiment, the electrochemical reaction unit 3 is provided on the side of the first plate-like body 1 opposite the second plate-like body 2, covering the gas flow-permitting portion 1A. However, the electrochemical reaction unit 3 may be provided on the side of the first plate-like body 1 facing the second plate-like body 2. In other words, the present invention is valid even if the electrochemical reaction unit 3 is configured to be disposed in the internal flow path A1.

[0231] (6) In the above embodiment, the first through portion 41 and the second through portion 51 are provided in pairs at both ends of the rectangular plate-like support body, but they are not limited to being provided at both ends, and two or more pairs may be provided. Moreover, the first through portion 41 and the second through portion 51 do not have to be provided in pairs. Therefore, one or more first through portion 41 and one or more second through portion 51 may be provided.

[0232] Furthermore, the plate-like support is not limited to a rectangular shape, and various shapes such as a square shape and a circular shape can be adopted.

[0233] (7) In the above description, the lower cover 203 and the upper cover 201 are joined by welding. However, the joining of the lower cover 203 and the upper cover 201 is not limited to welding, and they may be joined by, for example, bolts or the like.

[0234] (8) In the above description, the opening 201c is formed in the upper cover 201, and the opening 203c is formed in the lower cover 203. However, the openings 201c and 203c do not necessarily have to be formed.

[0235] (9) In the above, the electrochemical element stack S is sandwiched between the containers (first sandwiching body, second sandwiching body) 200. However, if the electrochemical element stack S can be sandwiched, there is no need to use the containers 200. For example, the electrochemical element stack S may be sandwiched between end plates (first sandwiching body, second sandwiching body) or the like.

[0236] (10) The first annular seal portion 42 and the second annular seal portion 52 may have any shape as long as they are configured to connect the first through-portions 41 and the second through-portions 51 to each other and prevent gas leakage. In other words, the first annular seal portion 42 and the second annular seal portion 52 may have an endless configuration with openings therein that communicate with the through-portions and be configured to seal between adjacent electrochemical elements A. The first annular seal portion 42 and the second annular seal portion 52 may be, for example, annular. The annular shape may be any shape, such as circular, elliptical, rectangular, or polygonal.

[0237] (11) In the above, the plate-like support 10 is composed of a first plate-like body 1 and a second plate-like body 2. Here, the first plate-like body 1 and the second plate-like body 2 may be composed of separate plate-like bodies, or may be composed of a single plate-like body. In this case, the first plate-like body 1 and the second plate-like body 2 are overlapped by bending the single plate-like body. Then, the first plate-like body 1 and the second plate-like body 2 are integrated by welding the peripheral edge portion 1a or the like. Note that the first plate-like body 1 and the second plate-like body 2 may be composed of a series of seamless plate-like bodies, or may be formed by bending a series of plate-like bodies.

[0238] (12) In the above embodiment, the electrochemical device includes an electrochemical module M including a plurality of electrochemical elements A. However, the electrochemical device of the above embodiment can also be applied to a configuration including one electrochemical element.

[0239] (13) In the above embodiment, a configuration (semi-open type) in which the distribution chamber 9 is provided inside the container 200 has been described, but a configuration (closed type: not shown) in which the distribution chamber 9 is not provided may also be used. In this case, instead of a configuration (semi-open type) in which the second gas supply unit 71 is provided on the side of the container 200, a configuration (closed type) in which the second gas supply unit 71 is provided above the container 200 may be used. [Example]

[0240] Example 1 The electrochemical module M of the present invention was manufactured according to the above-mentioned assembly method. In the gas seal portion 300 of the electrochemical module M, a Vermosal sheet S (manufactured by Nichias Corporation) was used as the gas seal material 301.

[0241] The properties of this gas sealing material 301 were examined, including density, the ratio of (load required for 20% compression) / (load required for 15% compression), the boron content, and the content of fibrous particles.

[0242] The density was calculated from the weight and thickness measurements of the gas seal material 301 cut into 5 cm squares. The ratio (load required for 20% compression) / (load required for 15% compression) was measured using an Instron testing machine (INSTRON5567, manufactured by Instron) with the contact point set as zero displacement, and calculated from the load relative to the displacement. The boron content was measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The content of fibrous particles (glass fiber, rock wool) was calculated by performing SEM observation and distinguishing fibrous particles from other particles using image analysis software (Example 1 of the present invention).

[0243] As Comparative Example 1 of the gas sealing material, Superwool HT-I (manufactured by Shin-Nihon Thermal Ceramics Co., Ltd.) was used, and its characteristics were investigated in the same manner as above. The results are shown in Figure 18 (compression test: (a) Invention Example 1, (b) Comparative Example 1) and Table 1.

[0244] [Table 1]

[0245] Example 2 In the electrochemical module M manufactured in Example 1, the electrochemical element stack S is placed inside the container 200 with the first clamping body 201 and the second clamping body 203 arranged so as to apply a predetermined clamping pressure to the electrochemical element stack S.

[0246] The environment was made to be similar to that of the electrochemical element laminate S, and the gas leakage rate of the gas seal portion 300 (gas seal material 301: invention example 1) was measured as follows.

[0247] Specifically, a ring-shaped gas seal 301 was placed on the flange, and a metal shim 10% thinner than the gas seal 301 was placed around the gas seal 301, and the flange was then tightened. The flange was connected to the gas supply port, and only the flange portion was placed in an electric furnace. The gas inlet was connected in the following order: ball valve, pressure gauge, flange, and ball valve. The outlet ball valve was closed, and gas was supplied to raise the temperature to 750°C. The air pressure was increased to 10 kPa at a rate of 0.5 L / min. After the pressure reached 10 kPa, the gas supply was stopped, the inlet ball valve was closed, and the pressure was maintained. The leak rate was calculated from the pressure drop after 10 minutes using the following formula:

[0248] Leak rate = (pressure immediately after holding - pressure after 10 minutes holding) / pressure immediately after holding x 100

[0249] As a result, the leak rate of the gas sealing material 301 in Inventive Example 1 was 35%. On the other hand, the gas sealing material in Comparative Example 1 had a large amount of air leakage and could not increase the pressure under the above conditions (10 kPa at 0.5 L / min).

[0250] Therefore, it was confirmed that the electrochemical module M in Inventive Example 1 had high temperature stability and a gas seal portion 300 that exhibited high gas sealing properties under a small load. [Industrial Applicability]

[0251] The present invention can be used in an electrochemical module and an energy system including the electrochemical module. [Explanation of symbols]

[0252] M Electrochemistry Module A. Electrochemical element GS gas seal structure S Electrochemical element stack 10 Plate-shaped support 31 Electrode layer 32 Electrolyte layer 33 Counter electrode layer 42 First annular seal 52 Second annular seal 200 containers 201 First clamping body 203 Second clamping body 300 Gas seal part 301 Gas seal material

Claims

1. a stack in which a plurality of electrochemical elements, each having an electrolyte layer and an electrode layer and a counter electrode layer disposed on either side of the electrolyte layer, are formed along a plate-like support, are stacked in a predetermined stacking direction via an annular seal portion for passing a first gas, which is one of a reducing component gas and an oxidizing component gas; an electrochemical module including a container that includes a first clamping body and a second clamping body, the first clamping body and the second clamping body being disposed so as to apply a predetermined clamping pressure to the stack, and the container containing the stack, the electrochemical element and another electrochemical element adjacent to the electrochemical element either above or below in the stacking direction are provided with gas seal portions on at least two opposing sides of the four sides of the plate-like support member, the gas seal portions having a gas seal structure that is affected by the clamping pressure of the first clamping body and the second clamping body; The gas seal portion contains fibrous particles and a silicon-based compound and has a density of 0.50 to 1.0 g / cm ３ and An electrochemical module having a gas seal material in which the ratio of (load required for 20% compression) / (load required for 15% compression) is in the range of 50-400.

2. 2. The electrochemical module according to claim 1, wherein the gas sealing material contains boron in an amount of 100 to 2000 ppm.

3. 3. The electrochemical module according to claim 1, wherein the content of the fibrous particles in the gas sealing material is 50 wt % or less.

4. 3. The electrochemical module according to claim 1, wherein the fibrous particles include at least one of glass fiber and rock wool.

5. 3. The electrochemical module according to claim 1, wherein the silicon-based compound includes at least one of vermiculite, wollastonite, and crystalline silica.

6. 3. The electrochemical module according to claim 1, wherein the gas seal structure is a structure in which the gas seal material is disposed in the gas seal portion in a state compressed by 5 to 20% in the thickness direction.

7. 3. The electrochemical module according to claim 1, wherein the gas seal portions are disposed on four sides of the plate-like support.

8. 3. The electrochemical module according to claim 1, wherein the electrolyte in the electrolyte layer is a solid oxide.

9. An energy system comprising the electrochemical module according to claim 8.

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