Method for producing electrochemical reaction device and electrochemical reaction device

Abstract

To provide a method for producing an electrochemical reaction device and an electrochemical reaction device, the method and device enabling reduction of manufacturing cost.SOLUTION: The invention relates to a method for manufacturing an electrochemical reaction device 1 including: an electrochemical cell 2 having an electrolyte layer 20, a first electrode 21, and a second electrode 22; a frame 3 having a support portion 31 and a frame main portion 32; and a sealing plate 4 that hermetically separates a second space 122 from an outer peripheral gap 11. The sealing plate 4 has an outer peripheral plate portion 42, an inner peripheral plate portion 41, and a connecting portion 43. The connecting portion 43 has a bent portion 430 that is curved in a convex state in a normal direction Z of the electrolyte layer 20. In forming the bent portion 430, after fixing the sealing plate 4 before the formation of the bent portion 430 to the electrochemical cell 2 and the frame 3, a buckling step is performed in which the connecting portion 43 is buckled by causing at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4 to undergo a volume change, thereby forming the bent portion 430.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an electrochemical reaction device and an electrochemical reaction device. [Background technology]

[0002] Various electrochemical reaction devices equipped with electrochemical cells, such as fuel cell devices and hydrogen generators, have been proposed. Patent Document 1 describes a fuel cell stack having a separator (hereinafter also referred to as a "sealing plate") joined to a single cell (hereinafter also referred to as an "electrochemical cell") via a glass seal. The sealing plate is connected between the electrochemical cell and a frame arranged around its periphery. The sealing plate is provided with a flexible portion to relieve stress generated at the joint between the sealing plate and the electrochemical cell (specifically, the glass seal). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6442364 Summary of the Invention [Problem to be solved by the invention]

[0004] However, performing press working, cutting, etc. to provide the flexible portion in the sealing plate increases the number of steps, which leads to an increase in manufacturing costs.

[0005] The present invention has been made in view of the above problems, and aims to provide a method for manufacturing an electrochemical reaction device and an electrochemical reaction device that can reduce manufacturing costs. [Means for solving the problem]

[0006] One aspect of the present invention is an electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) including a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; A method for manufacturing an electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the second space from the outer peripheral gap, comprising: the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, the connecting portion has a flexible portion (430) that is flexible in a convex state in the normal direction (Z) of the electrolyte layer, When forming the flexible portion, After fixing the sealing plate to the electrochemical cell and the frame before the flexible portion is formed, The method for manufacturing an electrochemical reaction device includes a buckling step of causing a volume change in at least one of the electrochemical cell, the frame, and the sealing plate, thereby buckling the connecting portion and forming the flexible portion.

[0007] Another aspect of the present invention is an electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) including a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; An electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the outer peripheral gap, the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, The connecting portion has a flexible portion (430) that is flexible in a convex state in a normal direction of the electrolyte layer, a buckling stress (Fcr) of the connecting portion is smaller than a force (F) acting on the connecting portion due to a volume change between at least one of the electrochemical cell, the frame, and the sealing plate, which occurs during at least one of a temperature increase / decrease treatment and a reduction treatment of the electrochemical cell; The buckling stress of the connecting portion is derived based on a predetermined buckling relational expression including the length (L) and bending rigidity (EI) of the connecting portion as parameters, and is present in the electrochemical reaction device. [Effects of the Invention]

[0008] In the method for manufacturing the electrochemical reaction device, the connecting portion is buckled by causing a volume change in at least one of the electrochemical cell, the frame, and the sealing plate, thereby forming the flexible portion. This makes it possible to form the flexible portion without directly processing the connecting portion, thereby reducing manufacturing costs.

[0009] In the electrochemical reaction device, the buckling stress of the connecting portion is lower than the force acting on the connecting portion due to volume changes between at least one of the electrochemical cell, the frame, and the sealing plate, which occur during at least one of temperature increase / decrease treatment and reduction treatment of the electrochemical cell. Therefore, the flexible portion can be formed during temperature increase / decrease treatment and reduction treatment of the electrochemical cell. Therefore, the flexible portion can be formed without directly processing the connecting portion. This reduces manufacturing costs.

[0010] As described above, according to the above aspects, it is possible to provide a method for manufacturing an electrochemical reaction device and an electrochemical reaction device that can reduce manufacturing costs. In addition, the symbols in parentheses in the claims and the means for solving the problems indicate the correspondence with the specific means described in the embodiments described below, and do not limit the technical scope of the present invention. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a plan view of a portion of the electrochemical reaction device according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional explanatory view of a part of the electrochemical reaction device, corresponding to a cross section taken along line II-II in FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view illustrating a portion of the assembly according to the first embodiment. [Figure 4] 3A and 3B are cross-sectional explanatory views showing the states before and after forming a flexible portion in the first embodiment. [Figure 5] 3 is an explanatory diagram of a temperature increase / decrease treatment and a reduction treatment of an electrochemical cell in the first embodiment. FIG. [Figure 6] 4 is a diagram showing a map of the relationship between the length of the connecting portion and the buckling stress in the first embodiment. [Figure 7] 5A and 5B are explanatory cross-sectional views showing the states before and after forming a flexible portion in a modified embodiment of the first embodiment. [Figure 8] 10A and 10B are cross-sectional explanatory views showing the states before and after forming a flexible portion in the second embodiment. [Figure 9] FIG. 10 is an explanatory diagram showing peeling between the sealing plate and the inner peripheral seal portion. [Figure 10] 11A and 11B are cross-sectional explanatory views showing the states before and after forming a flexible portion in the third embodiment. [Figure 11] FIG. 10 is an explanatory diagram showing the reversal of a flexible portion. [Figure 12] 10A and 10B are cross-sectional explanatory views showing the states before and after forming a flexible portion in the fourth embodiment. [Figure 13] 10A and 10B are explanatory cross-sectional views showing the states before and after forming a flexible portion in a modified form of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment 1) An embodiment of a method for manufacturing an electrochemical reaction device and an electrochemical reaction device will be described with reference to FIGS. As shown in FIGS. 1 and 2, the electrochemical reaction device 1 of this embodiment includes an electrochemical cell 2, a frame 3, and a sealing plate 4.

[0013] The electrochemical cell 2 has an electrolyte layer 20, a first electrode 21 provided on a first surface 201 of the electrolyte layer 20, and a second electrode 22 provided on a second surface 202 of the electrolyte layer 20 opposite the first surface 201. The frame 3 has a support portion 31 that supports the electrochemical cell 2 from the first surface 201 side, and a frame main body portion 32 arranged to surround the electrochemical cell 2 while providing a peripheral gap 11 between the frame and the peripheral edge of the electrochemical cell 2. The sealing plate 4 airtightly separates the second space 122 facing the second electrode 22 from the peripheral gap 11.

[0014] The sealing plate 4 has an outer peripheral plate portion 42, an inner peripheral plate portion 41, and a connecting portion 43. The outer peripheral plate portion 42 is a portion that is joined to the frame main body portion 32. The inner peripheral plate portion 41 is a portion that is joined to the electrochemical cell 2. The connecting portion 43 is a portion that connects the outer peripheral plate portion 42 and the inner peripheral plate portion 41. The connecting portion 43 has a bending portion 430 that is bent in a convex state in the normal direction Z of the electrolyte layer 20.

[0015] In the manufacturing method of the electrochemical reaction device 1 of this embodiment, the flexible portion 430 is formed by the following method. That is, to form the flexible portion 430, the sealing plate 4 before the flexible portion 430 is formed is fixed to the electrochemical cell 2 and the frame 3 as shown in Fig. 3, and then the following buckling step is performed. The buckling step is a step in which a volume change occurs in at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4, thereby buckling the connecting portion 43 and forming the flexible portion 430 as shown in Fig. 4.

[0016] The electrochemical reaction device 1 of this embodiment is an electrolysis cell device that generates hydrogen by electrolyzing water. The electrolysis cell device may be, for example, a device using an SOEC (i.e., a solid oxide electrolysis cell). In this case, the electrolyte layer 20 may be made of a solid oxide such as ceria.

[0017] In the following, unless otherwise specified, the electrochemical reaction device 1 of this embodiment will be described as an electrolysis cell device. However, the electrochemical reaction device of the present disclosure is not limited to this, and can also be, for example, a fuel cell device such as an SOFC.

[0018] The electrochemical reaction device 1 of this embodiment generates hydrogen by electrolyzing a raw material gas such as water vapor (HO). Air, which is an oxygen-containing gas, flows through the second space 122 facing the second electrode 22. Water vapor as the raw material gas and hydrogen as the generated gas flow through the first space 121 facing the first electrode 21. A sealing plate 4 is provided to prevent the oxygen-containing gas from mixing with the raw material gas and the generated gas.

[0019] The connecting portion 43 of the sealing plate 4 has the above-mentioned flexible portion 430. In this embodiment, both ends of the flexible portion 430 coincide with the outer end of the inner peripheral joining portion 131 and the inner end of the outer peripheral joining portion 132.

[0020] In the following description, the normal direction Z of the electrolyte layer 20 will be referred to as the Z direction where appropriate, and the arrangement direction X of the outer peripheral joint portion 132 and the inner peripheral joint portion 131 when viewed from the normal direction Z will be referred to as the X direction where appropriate. The direction perpendicular to both the X direction and the Z direction will be referred to as the Y direction. The X direction and the Y direction are defined based on the connecting portion 43 of interest. For example, when focusing on the connecting portion 43 along the left and right sides of the electrochemical cell 2 in FIG. 1, the left-right direction in the figure is the X direction, and when focusing on the connecting portion 43 along the top and bottom sides of the electrochemical cell 2 in the figure, the top and bottom direction in the figure is the X direction.

[0021] The inner peripheral plate portion 41 and the outer peripheral plate portion 42 of the sealing plate 4 are parallel to the X direction and the Y direction. In this embodiment, as shown in Fig. 2, the inner peripheral plate portion 41 and the outer peripheral plate portion 42 are at approximately the same height position in the Z direction.

[0022] In this embodiment, an inner circumferential seal portion 5 is interposed between the inner circumferential plate portion 41 and the electrochemical cell 2 to seal the space between them. In this embodiment, the inner circumferential seal portion 5 is made of a glass material. The inner circumferential seal portion 5 is disposed on a second surface 202 at the outer circumferential edge of the electrolyte layer 20 of the electrochemical cell 2. The inner circumferential seal portion 5 is formed around the entire outer circumferential edge of the electrolyte layer 20. The inner circumferential seal portion 5 is bonded to the inner circumferential plate portion 41 of the sealing plate 4 on the surface opposite the electrolyte layer 20. In this embodiment, the inner circumferential joint portion 131 is formed by the electrochemical cell 2, the inner circumferential seal portion 5, and the inner circumferential plate portion 41. The sealing plate 4 and the inner circumferential seal portion 5 airtightly separate the second space 122 and the outer circumferential gap 11.

[0023] The second electrode 22 of the electrochemical cell 2 is disposed inside the inner periphery seal portion 5. The first electrode 21 extends to the outer peripheral edge of the electrochemical cell 2. The first electrode 21 abuts against the support portion 31 of the frame 3 in the Z direction. The electrochemical cell 2 and the support portion 31 may be unfixed at this abutment portion. Not fixing this portion is preferable from the viewpoint of increasing the difference in linear expansion coefficients between the electrochemical cell 2 and the frame 3 and making buckling deformation more likely to occur at the connecting portion 43. Furthermore, not fixing this portion is preferable from the viewpoint of reducing thermal stress between the electrochemical cell 2 and the frame 3. However, a configuration in which this portion is fixed is also possible. The support portion 31 is provided with a number of ventilation holes 311. The ventilation holes 311 open toward the first electrode 21 of the electrochemical cell 2. The first space 121 faces the first electrode 21 via the multiple ventilation holes 311. The first space 121 is formed between the support portion 31 and the separator 14 .

[0024] The first electrode 21 and the second electrode 22 are made of a porous material. Therefore, water vapor and hydrogen permeate the first electrode 21. Furthermore, an oxygen-containing gas permeates the second electrode 22. As described above, the first electrode 21 and the support 31 are in contact with each other. However, because the first electrode 21 is porous, some of the raw material gas and generated gas in the first space 121 can permeate the first electrode 21 and move to the peripheral gap 11. A sealing plate 4 is provided to hermetically separate the raw material gas and generated gas in the peripheral gap 11 from the oxygen-containing gas in the second space 122.

[0025] The first space 121 is connected to a gas inlet path 123 for introducing a raw material gas and a gas outlet path 124 (see FIG. 1) for discharging the raw material gas and the generated gas. Also, reference numeral 125 shown in FIG. 1 denotes an air flow path connected to the first space 121.

[0026] 2, a flow path seal portion 126 is provided between the frame 3 and the separator 14 to airtightly separate the gas introduction path 123 and the second space 122. A current collector 15 that passes current to the second electrode 22 is disposed in the second space 122. Although not shown in the figure, the electrochemical reaction device 1 has a stack structure in which a plurality of electrochemical cells 2 and first spaces 121 and second spaces 122 formed on both sides thereof are stacked in the Z direction.

[0027] The frame 3 is made of, for example, a metal such as a material containing iron (specifically, for example, stainless steel or Crofer 22). The sealing plate 4 is made of, for example, a metal such as a material containing iron (specifically, for example, stainless steel, more specifically, for example, Crofer 22). An outer peripheral plate portion 42 of the sealing plate 4 is joined to the frame 3 by, for example, brazing or welding.

[0028] Next, an example of a method for manufacturing the electrochemical reaction device 1 of this embodiment will be specifically described. First, as shown in Fig. 3 , an assembly 10 is assembled by assembling components such as an electrochemical cell 2, a frame 3, a sealing plate 4, a separator 14, and a current collector 15. Here, the sealing plate 4 is fixed to the electrochemical cell 2 and the frame 3 before the flexible portion 430 (see Fig. 2 ) is formed. That is, the flat sealing plate 4 is fixed to the electrochemical cell 2 and the frame 3. In this embodiment, the portion of the sealing plate 4 that is joined to the electrochemical cell 2 is an inner peripheral plate portion 41, and the portion of the sealing plate 4 that is joined to the frame 3 is an outer peripheral plate portion 42.

[0029] More specifically, the inner peripheral plate portion 41 of the sealing plate 4 is joined to the upper surface of the outer peripheral edge of the electrochemical cell 2 via the inner peripheral seal portion 5. The outer peripheral plate portion 42 of the sealing plate 4 is joined to the upper surface of the frame main body portion 32 of the frame 3 by brazing, welding, or the like. For convenience, the "upper surface" of the electrochemical cell 2, the upper surface of the frame main body portion 32, and the like refers to the surface facing the same side as the second surface 202 of the electrolyte layer 20, and is not limited to a surface facing vertically upward. For convenience, the surface opposite the upper surface is referred to as the "lower surface." For convenience, the side facing the upper surface is referred to as the upper side, and the side facing the lower surface is referred to as the lower side. In this embodiment, the lower surface of the electrochemical cell 2 and the support portion 31 of the frame 3 are not fixed to each other. The assembly 10 is structurally substantially the same as the electrochemical reaction device 1, except that the connecting portion 43 does not have a flexible portion 430 formed therein.

[0030] The assembly 10 is subjected to the following temperature increase / decrease treatment and reduction treatment. At least one of the temperature increase / decrease treatment and the reduction treatment corresponds to the above-mentioned buckling step. That is, in at least one of the temperature increase / decrease treatment and the reduction treatment, a bending portion 430 is formed in the sealing plate 4 as shown in FIG. 4.

[0031] When the temperature increase / decrease treatment is a buckling process, the electrochemical cell 2 and the frame 3 are increased or decreased in temperature according to a predetermined temperature profile, thereby shortening the distance between the inner peripheral plate portion 41 and the outer peripheral plate portion 42, thereby causing the connecting portion 43 to buckle.

[0032] When the reduction treatment is a buckling process, the electrochemical cell 2 is subjected to a reduction treatment to reduce and expand the electrochemical cell 2, thereby shortening the distance between the inner plate portion 41 and the outer plate portion 42 and causing the connecting portion 43 to buckle. It is also conceivable that both the temperature increase / decrease treatment and the reduction treatment become buckling processes. For example, it is conceivable that the shortening of the distance between the inner peripheral plate portion 41 and the outer peripheral plate portion 42 due to the temperature increase / decrease treatment and the shortening of the distance between the inner peripheral plate portion 41 and the outer peripheral plate portion 42 due to the reduction treatment may combine to cause buckling of the connecting portion 43, thereby forming the deflected portion 430.

[0033] The temperature increase / decrease process is a process in which, when producing hydrogen in the electrochemical reaction device 1, the temperature is increased from room temperature T0 to a temperature T1 for activating the electrochemical cell 2, and then decreased to room temperature T0, as shown in Fig. 5 for example. Temperature T1 can be set to 580°C, for example. Furthermore, the time required for increasing the temperature from room temperature T0 to temperature T1 can be approximately 600 minutes, and the time required for decreasing the temperature from temperature T1 to room temperature T0 can be approximately 600 minutes.

[0034] During this temperature rise or fall, the frame 3, electrochemical cell 2, and sealing plate 4 expand or contract. As an example of bending the sealing plate 4 during temperature rise, first assume that the linear expansion coefficient of the electrochemical cell 2 is greater than that of the frame 3. In this case, the distance between the inner peripheral bonding portion 131 and the outer peripheral bonding portion 132 decreases due to temperature rise. Furthermore, the sealing plate 4 also expands due to temperature rise. If the force acting on the connecting portion 43 of the sealing plate 4 at this time exceeds the buckling stress, the connecting portion 43 of the sealing plate 4 bends, forming a bent portion 430, as shown in FIG. 4 .

[0035] The reduction treatment is a treatment in which the first electrode 21 of the electrochemical cell 2 is reduced with hydrogen. For example, the first electrode 21 contains ceria and nickel oxide. By reducing this nickel oxide to nickel metal, the first electrode 21 is formed in which nickel metal is dispersed in ceria. During this reduction treatment, cerium (IV) oxide is reduced, the valence of the ceria decreases, and the electrochemical cell 2 expands. This is called reduction expansion.

[0036] The reduction expansion of the electrochemical cell 2 accompanying this reduction treatment reduces the distance between the inner peripheral bonding portion 131 and the outer peripheral bonding portion 132. If the force acting on the connecting portion 43 of the sealing plate 4 at this time exceeds the buckling stress, the connecting portion 43 of the sealing plate 4 bends, forming a bent portion 430, as shown in FIG.

[0037] In this embodiment, the temperature increase / decrease treatment and the reduction treatment are performed as part of a series of treatments before actual operation. That is, after the assembly 10 is obtained, the temperature increase / decrease treatment and the reduction treatment are performed before actual operation (e.g., before shipping). For example, as shown in FIG. 5, the electrochemical cell 2 is heated from room temperature T0 to temperature T1 and maintained at that temperature T1. During this time, the reduction treatment is performed. That is, hydrogen is supplied to the first electrode 21 of the electrochemical cell 2. As a result, the electrochemical cell 2 is reduced and expands due to reduction. If the temperature T1 is too high, there is a concern that the electrochemical cell 2 will expand too much and deteriorate, while if it is too low, there is a concern that the electrochemical cell 2 will not be reduced enough and its performance will decrease. Therefore, the temperature T1 is set within a range that does not cause these concerns (e.g., 580°C). Furthermore, the buckling treatment can be more reliably performed by temporarily raising the temperature (e.g., 850°C) during the temperature increase. Next, an electrolytic reaction is caused to occur, that is, hydrogen is produced by supplying water vapor to the first electrode 21 and applying a voltage to the first electrode 21. Thereafter, the temperature of the electrochemical cell 2 is lowered to room temperature T0.

[0038] The buckling stress of the connecting portion 43 described above is determined based on the physical properties, dimensions, etc. of the sealing plate 4. Specifically, the buckling stress is derived based on a predetermined buckling relational expression that includes the length and bending rigidity of the connecting portion 43 as parameters.

[0039] Therefore, in this embodiment, the sealing plate 4 is designed such that the force acting on the connecting portion 43 in the buckling process (in this embodiment, at least one of the temperature rise / fall process and the reduction process) is higher than the buckling stress of the connecting portion 43. That is, in the buckling process, the buckling stress of the connecting portion 43 is smaller than the force acting on the connecting portion accompanying the volume change of at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4.

[0040] The buckling relational expression is represented by, for example, the following formula (1).

[0041]

Equation

[0042] In the above formula (1), Fcr represents the buckling stress, EI represents the bending rigidity of the connecting portion 43, and L represents the length of the connecting portion 43. The length L of the connecting portion 43 represents the length of the connecting portion 43 in the state before forming the bending portion 430. In other words, the length L is the straight-line distance between the inner peripheral joint portion 131 and the outer peripheral joint portion 132 in the state before forming the bending portion 430. Here, E represents the Young's modulus of the connecting portion 43, and I represents the second moment of area of the connecting portion 43. Further, λ is a coefficient determined by the restraint conditions at both ends of the connecting portion 43, and in this embodiment, λ = 1 to 4.

[0043] And the connecting portion 43 is designed such that the buckling stress Fcr obtained by the above formula (1) is smaller than the force F acting on the connecting portion 43 in the buckling process. That is, the bending rigidity EI and the length L of the sealing plate 4 are designed such that F < Fcr is satisfied. More specifically, the Young's modulus E and the second moment of area I that determine the bending rigidity EI are designed to appropriate values. Further, the second moment of area I is derived from I = bh , ,

[0043] ,

[0044] , , 3 , / 12. Here, b represents the width of the connecting portion 43 in the Y direction, and h represents the thickness of the connecting portion 43 (see FIGS. 1 and 4).

[0044] Thus, the material of the sealing plate 4, the dimensions of each of the connecting portions 43, etc. are appropriately selected and designed so that F < Fcr is satisfied. As a result, in the above-described buckling process, the bending portion 430 is appropriately formed. Note that the buckling stress Fcr and the force F acting on the connecting portion 43 are forces in the X direction.

[0045] The above-described design can be performed, for example, based on the map shown in FIG. 6. This map is a map showing the relationship between the length L of the connecting portion 43 and the buckling stress Fcr on the premise that the width b of the connecting portion 43 is 100 mm, the thickness h of the connecting portion 43 is 0.1 mm, and λ is 1. In addition, the relationship curves between the length L of the connecting portion 43 and the buckling stress Fcr when the Young's modulus E of the connecting portion 43 is 100 GPa, 150 GPa, 200 GPa, etc. are respectively shown. Further, the X-direction force F acting on the connecting portion 43 during the temperature rise / fall process and the reduction process, which is separately obtained, is set to 500 N.

[0046] From this map, by designing the length L such that the buckling stress Fc is less than 500 N along each relationship curve, the bending portion 430 is formed in the buckling process. For example, when a material with a Young's modulus E of 100 GPa is used as the sealing plate 4, the length L of the connecting portion 43 is designed to exceed 4 mm.

[0047] Note that in the buckling process, from the viewpoint of more surely forming the bending portion 430 and ensuring the durability strength of the sealing plate 4, it is also conceivable to design so that, for example, F × 0.6 ≦ Fcr ≦ F × 0.8. Also, from the same viewpoint, it is conceivable that the Young's modulus E of the sealing plate 4 is 50 to 200 GPa and the thickness h of the sealing plate 4 is 0.05 to 0.3 mm. Further, the width b of the connecting portion 43 can be, for example, 50 to 300 mm. For example, within these ranges, the respective parameters are set so that the buckling stress Fcr is less than the force F.

[0048] Next, the operation and effect of this embodiment will be described. In the method for manufacturing the electrochemical reaction device, a volume change occurs in at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4, causing the connecting portion 43 to buckle, thereby forming the flexible portion 430. This allows the flexible portion 430 to be formed without directly processing the connecting portion 43. This reduces manufacturing costs. As a result, the flexible portion 430 does not have any press processing marks or the like.

[0049] That is, in the electrochemical reaction device 1, as described above, after the assembly 10 is obtained by assembling the components together, a temperature increase / decrease treatment is generally performed before operation. Furthermore, depending on the material of the electrochemical cell 2, a reduction treatment of the electrochemical cell 2 may be necessary. During at least one of the temperature increase / decrease treatment and the reduction treatment, a force acts on the connecting portion 43. By utilizing this force to form the flexure portion 430, the number of steps can be reduced. In other words, a step just for forming the flexure portion 430 is not required. As a result, the manufacturing cost of the electrochemical reaction device 1 can be reduced. The buckling step is not a new step added for forming the flexure portion 430, but rather a step for performing a treatment normally required before actual operation to ensure the performance of the electrochemical reaction device 1. In other words, in this embodiment, an originally required step is also used as the buckling step.

[0050] In the electrochemical reaction device 1, the buckling stress Fcr of the connecting portion 43 is lower than the force F acting on the connecting portion due to volume changes between at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4, which occur during temperature increase / decrease treatment and reduction treatment of the electrochemical cell 2. Therefore, the flexible portion 430 can be formed during temperature increase / decrease treatment and reduction treatment of the electrochemical cell 2. Therefore, the flexible portion 430 can be formed without directly processing the connecting portion 43. This reduces manufacturing costs. Note that, since the connecting portion 43 has the flexible portion 430, the flexible portion 430 can absorb stress acting on the sealing plate 4 during use of the electrochemical reaction device 1, preventing damage to the inner peripheral joint portion 131 and the like.

[0051] Furthermore, the inner peripheral joining portion 131 has an inner peripheral seal portion 5 interposed between the inner peripheral plate portion 41 and the electrochemical cell 2. This makes it possible to improve the joining strength and airtightness of the inner peripheral joining portion 131.

[0052] As described above, according to the present embodiment, it is possible to provide a method for manufacturing an electrochemical reaction device and an electrochemical reaction device that can reduce manufacturing costs.

[0053] In the first embodiment, the protruding direction of the flexible portion 430 is set to the upward direction, but as shown in Fig. 7, the protruding direction of the flexible portion 430 may be set to the downward direction. That is, the flexible portion 430 is set to be convex toward the outer peripheral gap 11. The protruding direction of the flexible portion 430 can be controlled by, for example, making the gas pressure in the second space 122 higher than that in the first space 121, placing a weight on the sealing plate 4, or the like.

[0054] (Embodiment 2) 8, this embodiment is an electrochemical reaction device 1 having an inner circumferential pressing portion 61 that presses the inner circumferential plate portion 41 toward the inner circumferential seal portion 5. The inner circumferential pressing portion 61 is interposed between the separator 14 on the upper side of the second space 122 and the inner circumferential plate portion 41.

[0055] The inner peripheral pressing portion 61 is made of an insulating elastic material such as an alumina mat. 8, the inner peripheral pressing portion 61 is disposed between the inner peripheral plate portion 41 and the separator 14 before the flexible portion 430 is formed in the connecting portion 43. Thereafter, the flexible portion 430 is formed in the buckling step described above.

[0056] Other aspects are the same as those of embodiment 1. Note that, among the symbols used in embodiment 2 and onwards, the same symbols as those used in the previous embodiments represent the same components, etc. as those in the previous embodiments, unless otherwise specified.

[0057] In this embodiment, the bonding strength of the inner periphery bonding portion 131 can be improved. Specifically, if the inner periphery pressing portion 61 is not provided, and the adhesive strength between the inner periphery sealing portion 5 and the inner periphery plate portion 41 of the sealing plate 4 is insufficient, there is a concern that peeling may occur between the inner periphery sealing portion 5 and the sealing plate 4, as shown in FIG. 9 . A force in a direction that peels the inner periphery sealing portion 5 and the sealing plate 4 may occur, for example, during the buckling process described above or during use of the electrochemical reaction device 1. By providing the inner periphery pressing portion 61 as shown in FIG. 8 to resist such a force, the bonding strength of the inner periphery bonding portion 131 can be ensured. In other words, the provision of the inner periphery pressing portion 61 makes it possible to relatively reduce the adhesive strength between the inner periphery sealing portion 5 and the inner periphery plate portion 41 and the adhesive strength between the inner periphery sealing portion 5 and the electrochemical cell 2. This means, for example, greater freedom in the selection of materials for the inner periphery sealing portion 5 and the like. In addition, the same effects as those of the first embodiment are achieved.

[0058] (Embodiment 3) 10 , this embodiment is a form of an electrochemical reaction device 1 in which the bending portion 430 protrudes toward the outer peripheral gap 11 and has a bending pressing portion 62 that presses the bending portion 430 toward the outer peripheral gap 11. The bending pressing portion 62 is interposed between the separator 14 on the upper side of the second space 122 and the bending portion 430.

[0059] The deflection suppressor 62 is made of an insulating elastic material such as an alumina mat. 10 , the deflection holder 62 is disposed between the connecting portion 43 and the separator 14 before the deflection portion 430 is formed in the connecting portion 43. Then, the deflection portion 430 is formed in the buckling step described above. Even after the deflection portion 430 is formed, the deflection holder 62 remains in a state of pressing down the deflection portion 430. The rest is the same as in the first embodiment.

[0060] In this embodiment, it is possible to prevent the protruding direction of the flexible portion 430 from being reversed. That is, when the flexible portion 430 is not provided with the flexible portion 430, it is possible to prevent the protruding direction of the flexible portion 430 from being reversed upward as shown by the dashed line in FIG.

[0061] For example, if the protruding direction of the flexible portion 430 is reversed during the buckling process or when the electrochemical reaction device 1 is in use, there is a concern that this may cause peeling between the inner periphery seal portion 5 and the sealing plate 4. By providing the flexible portion 62, it is possible to prevent the flexible portion 430 from reversing and suppress peeling between the inner periphery seal portion 5 and the sealing plate 4. In other words, by providing the flexible portion 62, it is possible to make the adhesive force between the inner periphery seal portion 5 and the inner periphery plate portion 41 and the adhesive force between the inner periphery seal portion 5 and the electrochemical cell 2 relatively small. In other words, there is greater freedom in selecting materials for the inner periphery seal portion 5, etc. In addition, the same effects as those of the first embodiment are achieved.

[0062] (Embodiment 4) 12, this embodiment is an electrochemical reaction device 1 in which an inner peripheral plate portion 41 and an outer peripheral plate portion 42 of a sealing plate 4 are arranged at positions shifted from each other in the Z direction. In the example shown in FIG. 12, the inner peripheral plate portion 41 is arranged above the outer peripheral plate portion 42.

[0063] In this embodiment, too, before the buckling process, the connecting portion 43 connecting the inner peripheral plate portion 41 and the outer peripheral plate portion 42 is in a flat plate shape. Then, in the buckling process, the connecting portion 43 buckles, and the flexible portion 430 is formed.

[0064] The amount of misalignment in the Z direction between the inner peripheral plate portion 41 and the outer peripheral plate portion 42 can be set to, for example, about 0.05 to 0.5 mm. Other aspects are the same as in embodiment 1. This embodiment also has the same effects as embodiment 1.

[0065] 13, the present embodiment can be modified such that the inner peripheral plate portion 41 is disposed below the outer peripheral plate portion 42. In this case, the same effects as those of the first embodiment can be obtained.

[0066] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments within the scope of the present invention.

[0067] The features of the present invention are as follows. [1] An electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) including a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; A method for manufacturing an electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the second space from the outer peripheral gap, comprising: the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, the connecting portion has a flexible portion (430) that is flexible in a convex state in the normal direction (Z) of the electrolyte layer, When forming the flexible portion, After fixing the sealing plate to the electrochemical cell and the frame before the flexible portion is formed, a buckling step of causing a volume change in at least one of the electrochemical cell, the frame, and the sealing plate to buckle the connecting portion and form the flexible portion; [2] The method for manufacturing an electrochemical reaction device described in [1], wherein the buckling process involves raising and lowering the temperature of the electrochemical cell and the frame according to a predetermined temperature profile, thereby shortening the distance between the inner peripheral plate portion and the outer peripheral plate portion, thereby buckling the connecting portion. [3] The method for manufacturing an electrochemical reaction device according to [1] or [2], wherein the buckling step comprises reducing the electrochemical cell to reduce and expand the electrochemical cell, thereby shortening the distance between the inner peripheral plate portion and the outer peripheral plate portion, thereby buckling the connecting portion. [4] The method for manufacturing an electrochemical reaction device according to any one of [1] to [3], wherein the buckling stress (Fcr) of the connecting portion is smaller than the force (F) acting on the connecting portion in the buckling step due to a volume change of at least one of the electrochemical cell, the frame, and the sealing plate, and the buckling stress of the connecting portion is derived based on a predetermined buckling relational expression including the length (L) and bending rigidity (EI) of the connecting portion as parameters. [5] The method for manufacturing an electrochemical reaction device according to any one of [1] to [4], wherein the inner peripheral joining portion has an inner peripheral seal portion (5) interposed between the inner peripheral plate portion and the electrochemical cell. [6] The method for manufacturing an electrochemical reaction device according to [5], further comprising providing an inner peripheral pressing portion (61) that presses the inner peripheral plate portion toward the inner peripheral seal portion. [7] The method for manufacturing an electrochemical reaction device according to any one of [1] to [6], wherein the flexible portion protrudes toward the outer peripheral gap, and a flexible holding portion (62) is provided to hold the flexible portion toward the outer peripheral gap. [8] An electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) including a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; An electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the outer peripheral gap, the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, The connecting portion has a flexible portion (430) that is flexible in a convex state in a normal direction of the electrolyte layer, a buckling stress (Fcr) of the connecting portion is smaller than a force (F) acting on the connecting portion due to a volume change between at least one of the electrochemical cell, the frame, and the sealing plate, which occurs during at least one of a temperature increase / decrease treatment and a reduction treatment of the electrochemical cell; The electrochemical reaction device, wherein the buckling stress of the connection portion is derived based on a predetermined buckling relational expression including the length (L) and bending rigidity (EI) of the connection portion as parameters. [9] The electrochemical reaction device according to [8], wherein the inner peripheral joint portion has an inner peripheral seal portion (5) interposed between the inner peripheral plate portion and the electrochemical cell.

[10] The electrochemical reaction device according to [9], further comprising an inner peripheral pressing portion (61) that presses the inner peripheral plate portion toward the inner peripheral seal portion.

[11] The electrochemical reaction device according to [8] or [9], wherein the flexible portion protrudes toward the outer peripheral gap, and a flexible holding portion (62) is provided to hold the flexible portion toward the outer peripheral gap. [Explanation of symbols]

[0068] REFERENCE SIGNS LIST 1... electrochemical reaction device, 11... peripheral gap, 2... electrochemical cell, 201... first surface, 202... second surface, 21... first electrode, 22... second electrode, 3... frame, 31... support portion, 32... frame main body portion, 4... sealing plate, 41... inner peripheral plate portion, 42... outer peripheral plate portion, 43... connecting portion, 430... flexible portion

Claims

1. an electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) having a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; A method for manufacturing an electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the second space from the outer peripheral gap, comprising: the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, The connecting portion has a flexible portion (430) that is flexible in a convex state in the normal direction (Z) of the electrolyte layer, When forming the flexible portion, After fixing the sealing plate to the electrochemical cell and the frame before the flexible portion is formed, a buckling step of causing a volume change in at least one of the electrochemical cell, the frame, and the sealing plate to buckle the connecting portion and form the flexible portion;

2. 2. The method for manufacturing an electrochemical reaction device according to claim 1, wherein the buckling step reduces the distance between the inner peripheral plate portion and the outer peripheral plate portion by raising and lowering the temperature of the electrochemical cell and the frame according to a predetermined temperature profile, thereby buckling the connecting portion.

3. 3. The method for manufacturing an electrochemical reaction device according to claim 1, wherein the buckling step comprises reducing the electrochemical cell to reduce and expand the electrochemical cell, thereby shortening the distance between the inner peripheral plate portion and the outer peripheral plate portion, thereby buckling the connecting portion.

4. 3. The method for manufacturing an electrochemical reaction device according to claim 1, wherein a buckling stress (Fcr) of the connecting portion is smaller than a force (F) acting on the connecting portion in the buckling step due to a volume change of at least one of the electrochemical cell, the frame, and the sealing plate, and the buckling stress of the connecting portion is derived based on a predetermined buckling relational expression including a length (L) and a bending rigidity (EI) of the connecting portion as parameters.

5. 3. The method for manufacturing an electrochemical reaction device according to claim 1, wherein an inner peripheral seal portion (5) is interposed between the inner peripheral plate portion and the electrochemical cell to seal the gap between them.

6. The method for manufacturing an electrochemical reaction device according to claim 5, further comprising providing an inner peripheral pressing portion (61) that presses the inner peripheral plate portion toward the inner peripheral seal portion.

7. 3. The method for manufacturing an electrochemical reaction device according to claim 1, wherein the flexible portion protrudes toward the outer peripheral gap, and a flexible pressing portion (62) is provided to press the flexible portion toward the outer peripheral gap.

8. an electrochemical cell (2) having an electrolyte layer (20), a first electrode (21) provided on a first surface (201) of the electrolyte layer, and a second electrode (22) provided on a second surface (202) of the electrolyte layer opposite to the first surface; a frame (3) having a support portion (31) that supports the electrochemical cell from the first surface side, and a frame main body portion (32) that is arranged to surround the electrochemical cell while providing a peripheral gap (11) between the frame and a peripheral edge of the electrochemical cell; An electrochemical reaction device (1) having a second space (122) facing the second electrode and a sealing plate (4) that airtightly separates the second space from the outer peripheral gap, the sealing plate has an outer peripheral plate portion (42) joined to the frame main body portion, an inner peripheral plate portion (41) joined to the electrochemical cell, and a connecting portion (43) connecting the outer peripheral plate portion and the inner peripheral plate portion, The connecting portion has a flexible portion (430) that is flexible in a convex state in a normal direction of the electrolyte layer, a buckling stress (Fcr) of the connecting portion is smaller than a force (F) acting on the connecting portion in association with a volume change between at least one of the electrochemical cell, the frame, and the sealing plate, which occurs during at least one of a temperature increase / decrease treatment and a reduction treatment of the electrochemical cell; An electrochemical reaction device, wherein the buckling stress of the connection portion is derived based on a predetermined buckling relational expression including a length (L) and a bending rigidity (EI) of the connection portion as parameters.

9. 9. The electrochemical reaction device according to claim 8, wherein an inner peripheral seal portion (5) is interposed between the inner peripheral plate portion and the electrochemical cell to seal the gap between them.

10. 10. The electrochemical reaction device according to claim 9, further comprising an inner peripheral pressing portion (61) for pressing the inner peripheral plate portion toward the inner peripheral seal portion.

11. 10. The electrochemical reaction device according to claim 8, wherein the flexible portion protrudes toward the outer peripheral gap, and a flexible pressing portion (62) is provided to press the flexible portion toward the outer peripheral gap.

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