Electrochemical reaction device

Abstract

To provide an electrochemical reaction device that enables appropriate suppression of stress acting on an inner peripheral joint portion or an outer peripheral joint portion.SOLUTION: An electrochemical reaction device 1 includes: 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. A maximum assumed stress at an inner peripheral joint portion 131 where the electrochemical cell 2 and the inner peripheral plate portion 41 are joined and at an outer peripheral joint portion 132 where the frame main portion 32 and the outer peripheral plate portion 42 are joined is equal to or less than a reference strength, which is the lower one of the strength of the inner peripheral joint portion 131 and the strength of the outer peripheral joint portion 132. The maximum assumed stress is derived from a stress relationship formula including a bending rigidity of the sealing plate 4, a height of the connecting portion 43, and a maximum variation of an assumed length of the connecting portion 43.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrochemical reactor. [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). Patent Document 1 also describes setting the thickness and height of the sealing plate to predetermined values, etc. [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, to sufficiently prevent damage to the joint, there are other considerations to be made in addition to the conditions disclosed in Patent Document 1. That is, even if the conditions described in Patent Document 1 are met, the stress acting on the joint may be excessive. In some cases, it may be necessary to consider not only the stress at the joint (inner peripheral joint) between the sealing plate and the electrochemical cell, but also the stress at the joint (outer peripheral joint) between the sealing plate and the frame.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide an electrochemical reaction device that can appropriately suppress the stress acting on the inner peripheral joint portion or the outer peripheral joint portion. [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; 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 maximum expected stress at an inner peripheral joint (131) where the electrochemical cell and the inner peripheral plate are joined, and at an outer peripheral joint (132) where the frame main body and the outer peripheral plate are joined, is equal to or less than a reference strength which is the lower strength of the inner peripheral joint and the outer peripheral joint; The maximum expected stress is in the electrochemical reaction device, and is derived from a stress relational expression including the bending rigidity of the sealing plate, the height of the connecting portion in the normal direction (Z) of the electrolyte layer, and the maximum expected change in length of the connecting portion. [Effects of the Invention]

[0007] In the electrochemical reaction device, the maximum expected stress is equal to or less than the reference stress. The maximum expected stress is a value derived from a stress relational expression including the bending rigidity of the sealing plate, the height of the connecting portion in the normal direction of the electrolyte layer, and the maximum expected change in length of the connecting portion. This allows the stress acting on the inner peripheral bonding portion or the outer peripheral bonding portion to be appropriately suppressed.

[0008] As described above, according to the above aspect, it is possible to provide an electrochemical reaction device that can appropriately suppress the stress acting on the inner peripheral joint portion or the outer peripheral joint portion. 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]

[0009] [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. 3 is a cross-sectional explanatory view showing the structure around the sealing plate in the first embodiment. [Figure 4] 4A and 4B are explanatory diagrams showing the states of a flexible portion before and after deformation 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 Young's modulus E and maximum assumed shear stress τ of the sealing plate in the first embodiment. [Figure 7] 4 is a diagram showing a map of the relationship between the length Ld of the connecting portion and the maximum assumed shear stress τ in the first embodiment. [Figure 8] 10 is a diagram showing a map of the relationship between the length Ld of the connecting portion and the maximum assumed shear stress τ in an expanded range in the first embodiment. [Figure 9]4 is a diagram showing a map of the relationship between the thickness h of the connecting portion and the maximum assumed shear stress τ in the first embodiment. [Figure 10] 10 is a diagram showing a map of the relationship between the height ed of the flexure portion and the maximum assumed shear stress τ in the first embodiment. [Figure 11] 10 is a diagram showing a map of the relationship between the width w of the inner peripheral joint and the maximum assumed shear stress τ in the first embodiment. [Figure 12] FIG. 4 is an explanatory cross-sectional view showing the structure around the sealing plate in a modified embodiment of the first embodiment. [Figure 13] FIG. 10 is a cross-sectional view illustrating a portion of an assembly according to a second embodiment. [Figure 14] 10A and 10B are cross-sectional explanatory views showing the states before and after forming a flexible portion in the second embodiment. [Figure 15] 10 is a diagram showing a map of the relationship between the length L of the connecting portion and the buckling stress in the second embodiment. [Figure 16] FIG. 11 is a cross-sectional explanatory view showing the structure around the sealing plate in the third embodiment. [Figure 17] 11 is a diagram showing a map of the relationship between Young's modulus E and maximum assumed shear stress τ of the sealing plate in the third embodiment. [Figure 18] 11 is a diagram showing a map of the relationship between the height e of the connecting portion and the maximum assumed shear stress τ in the third embodiment. [Figure 19] 11 is a diagram showing a map of the relationship between the thickness h of the connecting portion and the maximum assumed shear stress τ in the third embodiment. [Figure 20] 11 is a diagram showing a map of the relationship between the length Ld of the connecting portion and the maximum assumed shear stress τ in the third embodiment. [Figure 21] 11 is a diagram showing a map of the relationship between the height e of the connecting portion and the maximum assumed shear stress τ in the third embodiment. [Figure 22] 11 is a diagram showing a map of the relationship between the width w of the inner peripheral joint and the maximum assumed shear stress τ in the third embodiment. [Figure 23] FIG. 11 is an explanatory cross-sectional view showing the structure around the sealing plate in a modified embodiment of the third embodiment. [Figure 24] FIG. 10 is a cross-sectional explanatory view showing the structure around the sealing plate in the fourth embodiment. [Figure 25]FIG. 13 is an explanatory cross-sectional view showing the structure around the sealing plate in a modified embodiment of the fourth embodiment. [Figure 26] FIG. 11 is a cross-sectional explanatory view showing the structure around the sealing plate in the fifth embodiment. [Figure 27] FIG. 10 is an explanatory diagram showing peeling between the sealing plate and the inner peripheral seal portion. [Figure 28] FIG. 13 is a cross-sectional explanatory view showing the structure around the sealing plate in the sixth embodiment. [Figure 29] FIG. 10 is an explanatory diagram showing the reversal of a flexible portion. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment 1) An embodiment of 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.

[0011] 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.

[0012] 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 together.

[0013] The maximum expected stress at the inner peripheral joint 131 between the electrochemical cell 2 and the inner peripheral plate 41 and the outer peripheral joint 132 between the frame main body 32 and the outer peripheral plate 42 is equal to or less than the reference strength. The reference strength is the lower of the strength of the inner peripheral joint 131 and the strength of the outer peripheral joint 132.

[0014] The maximum expected stress is derived from a stress relational expression that includes the bending rigidity of the sealing plate 4, the height of the connecting portion 43 in the normal direction Z of the electrolyte layer 20, and the expected maximum change in the length of the connecting portion 43. The length of the connecting portion 43 is the linear distance between both ends of the connecting portion 43, i.e., the linear distance between the inner peripheral bonding portion 131 and the outer peripheral bonding portion 132.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] In this embodiment, the connecting portion 43 of the sealing plate 4 has a flexed portion 430 that is flexed in a convex state in the normal direction Z of the electrolyte layer 20. In this embodiment, as shown in FIG. 3, both ends of the flexed 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. That is, in this embodiment, the length L of the connecting portion 43 d is the length of the flexure 430.

[0019] 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.

[0020] 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 Figures 2 and 3, the inner peripheral plate portion 41 and the outer peripheral plate portion 42 are at approximately the same height position in the Z direction.

[0021] The reference strength is the lower strength of the inner circumferential bonded portion 131 or the outer circumferential bonded portion 132. In this embodiment, the inner circumferential bonded portion 131 has a lower strength than the outer circumferential bonded portion 132. Therefore, in this embodiment, the reference strength is the strength of the inner circumferential bonded portion 131. This point will be described later.

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

[0023] The second electrode 22 of the electrochemical cell 2 is disposed inside the inner circumferential seal portion 5. The first electrode 21 is provided up 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. At this abutment portion, the electrochemical cell 2 and the support portion 31 may be unfixed. From the viewpoint of reducing thermal stress between the electrochemical cell 2 and the frame 3, it is preferable that this portion is unfixed. However, this portion may also be fixed. 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. A 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 source 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 airtightly separate the source 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 a metal such as an iron-containing material (specifically, stainless steel, Crofer 22, etc.). The sealing plate 4 is made of a metal such as an iron-containing material (specifically, stainless steel, more specifically, Crofer 22, etc.). The outer peripheral plate portion 42 of the sealing plate 4 is joined to the frame 3 by, for example, brazing or welding. That is, the outer peripheral joint portion 132 is a joint between metals, and the joint strength can be increased. On the other hand, the inner peripheral joint portion 131 is a joint between the inner peripheral seal portion 5 and the inner peripheral plate portion 41 of the sealing plate 4, or a joint between the inner peripheral seal portion 5 and the electrochemical cell 2, and therefore it is relatively difficult to increase the joint strength. Therefore, in this embodiment, the above-mentioned reference strength is the strength at the inner peripheral joint portion 131.

[0028] The maximum expected stress is equal to or less than the standard strength. In this embodiment, from the viewpoint of ensuring a safety factor and durability, the maximum expected stress is preferably equal to or less than 90% of the standard strength, and more preferably 25 to 50%. That is, it is necessary to ensure that the stress acting on the inner peripheral bonding portion 131 is less than the standard strength, while also ensuring the durability of the sealing plate 4. From this viewpoint, it is desirable that the maximum expected stress has the above-mentioned relationship with the standard strength.

[0029] From the same viewpoint, it is also possible to set the Young's modulus E of the sealing plate 4 to 50 to 200 GPa and the thickness h of the sealing plate 4 to 0.05 to 0.3 mm. The width b of the connecting portion 43 can be set to, for example, 50 to 300 mm. For example, each parameter is set within these ranges so that the maximum expected stress is equal to or less than the reference stress.

[0030] As described above, the electrochemical reaction device 1 of this embodiment is designed so that the maximum expected stress of the sealing plate 4 is equal to or less than the reference stress. As described above, the maximum expected stress is calculated based on a stress relational expression including the bending rigidity of the sealing plate 4 and the maximum expected change in length of the connecting portion 43. The maximum expected change in length of the connecting portion 43, ΔL, is d For example, it can be assumed as follows: When the electrochemical reaction device 1 is operated, the flexible portion 430 is deformed as the dimensions of each portion change, as shown in FIG. d and height e d In the figure, the flexible portion 430 shown by the broken line indicates the state before deformation, and the flexible portion 430 shown by the solid line indicates the state after deformation. The length L of the connecting portion 43 that occurs while the electrochemical reaction device 1 is operated d The maximum change in the amount of change ΔL d It can be said that:

[0031] The dimensional changes of each part are expected to be caused by, for example, expansion and contraction of the frame 3 due to temperature changes, expansion and contraction of the electrochemical cells 2, and further dimensional changes due to reduction expansion of the electrochemical cells 2. These dimensional changes cause stress to act on the sealing plate 4, which in turn acts on the inner peripheral bonding portion 131, causing deformation of the flexible portion 430. If the stress can be absorbed by deformation of the flexible portion 430, the stress acting on the inner peripheral bonding portion 131 will be reduced accordingly.

[0032] Therefore, as described above, the maximum expected stress can be calculated based on the expected maximum change ΔL in the length of the connecting portion 43 and the bending rigidity EI of the sealing plate 4. This maximum expected stress is equal to or less than the reference stress.

[0033] In this embodiment, the maximum expected stress is the maximum stress that is expected to act on the inner peripheral bonding portion 131 during the following temperature increase / decrease treatment and the following reduction treatment. 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] The temperature increase / decrease treatment is performed both before and during the actual operation of the electrochemical reaction device 1. That is, there is a temperature increase / decrease treatment performed before and after the reduction treatment described below, and a temperature increase / decrease treatment performed when electrolyzing the raw material gas during the actual operation after the reduction treatment.

[0035] During this temperature rise or fall, the frame 3 and the electrochemical cell 2 expand or contract. If the linear expansion coefficients of the two are different, stress in the X direction acts on the sealing plate 4 that connects them. Part of this stress is absorbed by the deformation of the bending portion 430 of the sealing plate 4, but the remaining stress acts on the inner peripheral bonding portion 131 and the outer peripheral bonding portion 132.

[0036] 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.

[0037] The reduction expansion of the electrochemical cell 2 caused by this reduction treatment causes stress to act on the sealing plate 4, part of which is absorbed by the bending portion 430, and the other part of which acts on the inner peripheral bonding portion 131. These stresses are stresses in the X direction.

[0038] As such, the expected stress on the inner peripheral joint 131 includes stress due to dimensional changes of each part due to temperature rise and fall, and stress due to reduction and expansion of the electrochemical cell 2. Therefore, in this embodiment, the maximum expected stress is defined as the maximum expected stress, taking these factors into consideration.

[0039] The stress acting on the sealing plate 4 due to the volumetric changes of each part caused by the temperature increase / decrease treatment and the reductive expansion of the electrochemical cell 2 caused by the reduction treatment can be specifically obtained from the conditions of each treatment and the material, dimensions, shape, etc. of each part. In addition, the stress absorbed by the flexible portion 430 can also be specifically obtained based on the shape, material, dimensions, etc. of the flexible portion 430. Therefore, the maximum value of the stress expected to act on the inner peripheral bonding portion 131, i.e., the maximum expected stress, can also be specifically obtained.

[0040] As described above, in this embodiment, the stress and strength are defined as shear stresses acting on the inner peripheral joint 131. That is, the maximum assumed shear stress τ as the maximum assumed stress and the standard shear stress τs as the standard strength are designed to satisfy τ≦τs. More preferably, they are designed to satisfy τ≦0.9×τs, and even more preferably, 0.25×τs≦τ≦0.5×τs.

[0041] The stress relation is expressed as follows: d , and the length L of the flexible portion 430 d That is, in this embodiment, the height of the connecting portion 43 is the height e of the flexible portion 430. d The length of the connecting portion 43 is the length L of the flexible portion 430. d In this embodiment, the stress relational expression is the following expression (1).

[0042]

number

[0043] In the formula (1), S is the bonding area of ​​the inner peripheral bonding portion 131. δ is the area of ​​the inner peripheral bonding portion 131, as shown in FIG. d and ΔL d The bonded area S is determined as the product of the width w of the inner peripheral bonded portion 131 in the X direction and the length b of the inner peripheral bonded portion 131 in the Y direction. EI represents the bending rigidity of the connecting portion 43, E represents the Young's modulus of the sealing plate 4, and I represents the second moment of area of ​​the sealing plate 4.

[0044] Each parameter is designed so that the maximum assumed shear stress τ obtained based on the above formula (1) satisfies τ≦τs, more preferably τ≦0.9×τs, and even more preferably 0.25×τs≦τ≦0.5×τs.

[0045] For example, when designing the Young's modulus E of the sealing plate 4, it is possible to use a relationship map such as that shown in FIG. 6. This relationship map shows the relationship between the Young's modulus E and the maximum expected shear stress τ, which is obtained based on the above formula (1). However, the assumptions are that b = 100 mm, h = 0.1 mm, and e d = 0.1 mm, w = 3 mm. d is calculated for 2.5mm, 5mm, and 10mm.

[0046] Based on this map, for example, the reference stress (here, the reference shear stress τs) is 5 MPa, L d = 2.5, the Young's modulus E is set to 141 GPa or less.

[0047] In addition, the length L of the connecting portion 43 d When designing the length L (here, the length of the flexible portion 430), it is possible to use a relationship map such as that shown in FIG. 7. This relationship map is obtained based on the above formula (1) andd and the maximum assumed shear stress τ. d , w are as described above. Also, as shown in the figure, Young's modulus E is calculated for each of 100 GPa, 150 GPa, and 200 GPa.

[0048] Based on this map, for example, if the reference stress (here, the reference shear stress τs) is 5 MPa and E=100 GPa, the length L of the flexure 430 is d is set to 2.1 mm or more.

[0049] The length L of the flexible portion 430 d Regarding L, as shown in Figure 8, d The relationship map between the maximum assumed shear stress τ and the Young's modulus E is shown here as 150 GPa. d <5mm, L d The change in τ due to the change in L d When the value is less than 2 mm, the change in τ becomes large. d It is preferable that the thickness is 2 mm or more, and more preferably 5 mm or more.

[0050] On the other hand, L d When L is 10 mm or more, τ hardly changes. d When it is 10 mm or more, L d The effect of suppressing τ by increasing L d Increasing L may lead to an increase in the size of the electrochemical reaction device 1. d It is more preferable to set the value to ≦10 mm.

[0051] Considering the above points, 2mm≦L d ≦10mm, more preferably 5mm≦L d It is desirable to set each parameter so that τ≦τs is satisfied while satisfying ≦10 mm.

[0052] The Young's modulus E of the sealing plate 4 and the length L of the flexible portion 430 d Besides, thickness h, height e d 9 to 11, the relationship maps shown in FIGS. 9 to 11 are obtained for the width w of the inner peripheral bonding portion 131 based on the above formula (1).

[0053] Figure 9 shows the relationship between thickness h and shear stress τ. Here, the assumptions are b = 100 mm, e d =0.1mm, w=3mm, L d = 5 mm. If the thickness h exceeds 0.3 mm, the increase in τ with the increase in thickness h becomes large. From this viewpoint, it is preferable that h ≦ 0.3 mm. Furthermore, in consideration of the durability strength of the sealing plate 4, it is preferable that h ≧ 0.05 mm. Considering the above viewpoints, it is desirable to set each parameter so that τ ≦ τs is satisfied while satisfying 0.05 mm ≦ h ≦ 0.3 mm.

[0054] Figure 10 shows the height e d and shear stress τ. Here, the assumptions are b = 100 mm, h = 0.1 mm, w = 3 mm, L d The height e of the flexible portion 430 is set to 5 mm. d For more than 0.5 mm, e d The effect of suppressing τ by increasing e d Increasing e may lead to interference of the flexible portion 430 with the surrounding members. d It is more preferable to set the value to ≦0.5 mm. d It is desirable to set each parameter so that τ≦τs is satisfied while satisfying ≦0.5 mm.

[0055] Figure 11 shows the relationship between width w and shear stress τ. Here, the assumptions are b = 100 mm, h = 0.1 mm, e d =0.1mm, L d= 5 mm. If the width w exceeds 10 mm, the effect of increasing w in suppressing τ decreases. Increasing w can lead to an increase in the size of the electrochemical reaction device 1, so it is more preferable to set w ≦ 10 mm. Considering the above points, it is desirable to set each parameter so that τ ≦ τs is satisfied while satisfying w ≦ 10 mm.

[0056] As described above, the thickness h and height e are calculated using the above map based on the stress relation (the above equation (1)). d It is possible to design the width w of the inner peripheral joining portion 131.

[0057] (Design method) In other words, it can be said that the electrochemical reaction device 1 of this embodiment is designed based on the following design method.

[0058] That is, the design method of the electrochemical reaction device 1 of this embodiment is as follows: an electrochemical cell including an electrolyte layer, a first electrode provided on a first surface of the electrolyte layer, and a second electrode provided on a second surface of the electrolyte layer opposite to the first surface; a frame including a support portion that supports the electrochemical cell from the first surface side, and a frame main body portion that is arranged to surround the electrochemical cell while providing a peripheral gap between the frame and a peripheral edge of the electrochemical cell; A method for designing an electrochemical reaction device having a sealing plate that airtightly separates a second space facing the second electrode from the outer peripheral gap, the method comprising: the sealing plate has an outer peripheral plate portion joined to the frame main body portion, an inner peripheral plate portion joined to the electrochemical cell, and a connecting portion connecting the outer peripheral plate portion and the inner peripheral plate portion, designing the electrochemical cell and the inner peripheral plate portion to be joined together, and the outer peripheral plate portion to be joined together, so that the maximum expected stress at the inner peripheral joint portion is equal to or less than the lower strength of the inner peripheral joint portion and the outer peripheral joint portion; The method for designing an electrochemical reaction device includes the step of deriving the maximum expected stress from a stress relational expression including the bending rigidity of the sealing plate, the height of the connecting portion in the normal direction of the electrolyte layer, and the maximum expected change in length of the connecting portion.

[0059] Furthermore, when manufacturing the electrochemical reaction device 1 of this embodiment, the flexible portion 430 is formed in the connecting portion 43. The flexible portion 430 can be formed, for example, by performing a press process, a bending process, or the like before bonding the sealing plate 4 to the electrochemical cell 2 and the frame 3. Alternatively, as shown in a second embodiment described later, the flexible portion 430 can be formed in the sealing plate 4 after bonding the sealing plate 4 to the electrochemical cell 2 and the frame 3.

[0060] In the electrochemical reaction device 1, the maximum assumed stress (maximum assumed shear stress τ in this embodiment) is equal to or less than the reference stress (reference shear stress in this embodiment). The maximum assumed stress is calculated by multiplying the bending rigidity EI of the sealing plate 4 by the height e of the bending portion 430 of the sealing plate 4. d and the assumed length L of the connecting portion 43 d The maximum change in ΔL d This is a value derived from a stress relational expression including the following: As a result, the stress acting on the inner periphery bonding portion 131 can be appropriately suppressed.

[0061] In other words, it is possible to appropriately set each parameter while accurately grasping the maximum expected stress and the reference stress, which makes it possible to reduce the stress acting on the inner peripheral joint 131 while taking into consideration various aspects such as the miniaturization, weight reduction, and cost reduction of the device.

[0062] Furthermore, since the connecting portion 43 has the flexible portion 430, the maximum expected stress acting on the inner periphery joint portion 131 can be effectively reduced.

[0063] The inner peripheral joining portion 131 has an inner peripheral seal portion 5. This can improve the joining strength and airtightness of the inner peripheral joining portion 131.

[0064] As described above, according to this embodiment, it is possible to provide an electrochemical reaction device that can appropriately suppress the stress acting on the inner peripheral joint portion.

[0065] In the first embodiment, an example in which the protruding direction of the flexible portion 430 is set to the upward direction has been shown, but as shown in Fig. 12, the protruding direction of the flexible portion 430 may also be set to the downward direction. That is, the flexible portion 430 is set to be convex toward the outer peripheral gap 11. In this case, each parameter can be designed in the same way as in the first embodiment.

[0066] (Embodiment 2) 13 to 15, an example of a manufacturing method for the electrochemical reaction device 1 is shown. When this manufacturing method is adopted, the above-mentioned maximum expected stress (for example, maximum expected shear stress τ) is set as the maximum stress (shear stress) that is expected to act when the temperature rises and falls during actual operation after the reduction treatment.

[0067] 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, as shown in Fig. 13, the sealing plate 4 before the flexible portion 430 is formed is fixed to the electrochemical cell 2 and the frame 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. 14. The buckling step is performed during at least one of the temperature increase / decrease treatment and the reduction treatment before the electrochemical reaction device 1 starts operating.

[0068] First, as shown in Fig. 13, 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 before the flexible portion 430 (see Fig. 2) is formed is fixed to the electrochemical cell 2 and the frame 3. In other words, the flat sealing plate 4 is fixed to the electrochemical cell 2 and the frame 3.

[0069] 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 the 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. Not fixing these portions is preferable from the viewpoint of increasing the difference in linear expansion coefficient between the electrochemical cell 2 and the frame 3 and making buckling deformation more likely to occur in the connecting portion 43. 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.

[0070] 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. 14 .

[0071] 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.

[0072] 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.

[0073] As an example of bending of 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. 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. 14 .

[0074] One possible way to deflect the sealing plate 4 during the reduction treatment is to utilize the reduction expansion of the electrochemical cell 2. That is, the reduction expansion of the electrochemical cell 2 accompanying the 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 deflects, forming a deflected portion 430, as shown in FIG.

[0075] 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.

[0076] Therefore, in this embodiment, the sealing plate 4 is designed so that the force acting on the connecting portion 43 in the buckling process (in this embodiment, at least one of the temperature increase / decrease treatment and the reduction treatment) is higher than the buckling stress of the connecting portion 43. In other words, in the buckling process, the buckling stress of the connecting portion 43 is smaller than the force acting on the connecting portion due to a volume change of at least one of the electrochemical cell 2, the frame 3, and the sealing plate 4.

[0077] The buckling relation is expressed, for example, by the following equation (2).

[0078]

Number

[0079] In the above formula (2), 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. Note that the length L of the connecting portion 43 represents the length of the connecting portion 43 in the state before forming the bent 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 bent 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.

[0080] Then, the connecting portion 43 is designed such that the buckling stress Fcr obtained by the above formula (2) 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 by I = bh 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 14).

[0081] Thus, the material of the sealing plate 4, the dimensions of the connecting portion 43, etc. are appropriately selected and designed such that F < Fcr is satisfied. Thereby, in the above-described buckling process, the bent 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.

[0082] The above design may be performed, for example, based on the map shown in Figure 15. This map shows the relationship between the length L of connecting portion 43 and the buckling stress Fcr, assuming that the width b of connecting portion 43 is 100 mm, the thickness h of connecting portion 43 is 0.1 mm, and λ is 1. The map also shows relationship curves between the length L of connecting portion 43 and the buckling stress Fcr when the Young's modulus E of connecting portion 43 is set to 100 GPa, 150 GPa, and 200 GPa. The force F in the X direction acting on connecting portion 43 during the temperature increase / decrease treatment and the reduction treatment, which is obtained separately, is set to 500 N.

[0083] By designing the length L from this map along each relationship curve so that the buckling stress Fc is less than 500 N, the flexible portion 430 is formed in the buckling process. For example, when a material with a Young's modulus E of 100 GPa is used for the sealing plate 4, the length L of the connecting portion 43 is designed to exceed 4 mm.

[0084] In addition, from the viewpoint of more reliably forming the flexible portion 430 in the buckling step and ensuring the durability of the sealing plate 4, it is also possible to design it so that F×0.6≦Fcr≦F×0.8, for example. From the same viewpoint, it is also possible to set the Young's modulus E of the sealing plate 4 to 50 to 200 GPa and the thickness h of the sealing plate 4 to 0.05 to 0.3 mm. The width b of the connecting portion 43 can be set to, for example, 50 to 300 mm. For example, each parameter is set within these ranges so that the buckling stress Fcr is less than the force F.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] As described above, according to this embodiment, it is possible to provide a method for manufacturing an electrochemical reaction device that can reduce manufacturing costs.

[0091] As a method for manufacturing an electrochemical reaction device that conceptually includes the manufacturing method shown in the second embodiment, 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, There is a method for manufacturing an electrochemical reaction device, which includes 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.

[0092] (Embodiment 3) As shown in FIG. 16, this embodiment is a form of an electrochemical reaction device 1 in which the outer peripheral plate portion 42 and the inner peripheral plate portion 41 of the sealing plate 4 are arranged so as to be shifted in the Z direction. In this embodiment, the connecting portion 43 does not have a flexible portion 430. That is, the connecting portion 43 is formed in a flat plate shape. That is, the connecting portion 43 is formed along a plane that is inclined with respect to the X direction.

[0093] In this embodiment, the height of the connecting portion 43 in the Z direction is the difference in height position in the Z direction between the outer peripheral plate portion 42 and the inner peripheral plate portion 41. In this embodiment, this difference is referred to as height e. Note that this height e corresponds to the eccentricity of the shear load acting on the sealing plate 4. Furthermore, the length of the connecting portion 43 is the length of the connecting portion 43 when viewed from the Y direction, and is the linear distance between the outer peripheral plate portion 42 and the inner peripheral plate portion 41. In this embodiment, the length of this connecting portion 43 is referred to as length L d That's what they say.

[0094] In this embodiment, the maximum expected stress is calculated by the bending rigidity EI of the sealing plate 4, the height e of the connecting portion 43, and the expected length L of the connecting portion 43. d The maximum change in ΔL d It is derived from the stress relation including

[0095] In this embodiment, the stress relational expression can be the following expression (3).

[0096]

number

[0097] Each parameter is designed so that the maximum assumed shear stress τ obtained based on the above formula (3) satisfies τ≦τs.

[0098] For example, when designing the Young's modulus E of the sealing plate 4, it is possible to use a relationship map such as that shown in FIG. 17. This relationship map shows the relationship between the Young's modulus E and the maximum expected shear stress τ, which is obtained based on the above formula (3). However, it is assumed that b = 100 mm, h = 0.1 mm, e d= 0.1 mm, w = 3 mm. As shown in the figure, Ld is calculated for 2.5 mm, 5 mm, and 10 mm.

[0099] Based on this map, for example, the reference stress (here, the reference shear stress τs) is 5 MPa, L d = 2.5 mm, the Young's modulus E is set to 150 GPa or less.

[0100] When designing the height e (i.e., the amount of eccentricity) of the connecting portion 43, it is possible to use a relationship map as shown in Fig. 18. This relationship map is obtained based on the above formula (3) and the length L d and the maximum assumed shear stress τ. b, h, and w are as described above. Young's modulus E was set to 150 GPa.

[0101] Based on this map, for example, if the reference stress (here, reference shear stress τs) is 2 MPa and Ld=2.5 mm, the height e (eccentricity) of the connecting portion 43 is set to 0.8 mm or more.

[0102] In addition to the Young's modulus E of the sealing plate 4, the thickness h and length L d 19 to 22 are obtained based on the above formula (3) for the thickness h, the length L in the first embodiment. d , height e d The tendency is roughly the same as the map showing the relationship between the width w of the inner peripheral joint 131 and the maximum assumed shear stress τ.

[0103] Figure 19 shows the relationship between thickness h and shear stress τ. Here, the assumptions are b = 100 mm, e = 0.1 mm, w = 3 mm, L d From this relationship map, it can be said that it is desirable to set each parameter so as to satisfy 0.05 mm≦h≦0.3 mm and τ≦τs, from the same viewpoint as in the first embodiment.

[0104] Figure 20 shows the length L d and shear stress τ. Here, it is assumed that b = 100 mm, e = 0.1 mm, h = 0.1 mm, and w = 3 mm. From this relationship map, from the same perspective as in the first embodiment, 2 mm ≦ L d ≦10mm, more preferably 5mm≦L d It is desirable to set each parameter so that τ≦τs is satisfied while satisfying ≦10 mm.

[0105] Figure 21 shows the relationship between height e and shear stress τ. Here, the assumptions are b = 100 mm, h = 0.1 mm, w = 3 mm, L d From this relationship map, it can be said that it is desirable to set each parameter so as to satisfy e≦0.5 mm and τ≦τs, from the same viewpoint as in the first embodiment.

[0106] Figure 22 shows the relationship between width w and shear stress τ. Here, the assumptions are b = 100 mm, h = 0.1 mm, e d =0.1mm, L d = 5 mm. When the width w exceeds 10 mm, the effect of suppressing τ by increasing w becomes smaller. From this relationship map, it can be said that, from the same perspective as in the first embodiment, it is desirable to set each parameter so as to satisfy w≦10 mm and τ≦τs.

[0107] As described above, the thickness h and height e are calculated using the above map based on the stress relation (the above equation (3)). d It is possible to design the width w of the inner peripheral joining portion 131. The rest is the same as in the first embodiment.

[0108] This embodiment also provides an electrochemical reaction device 1 that can appropriately suppress the stress acting on the inner peripheral bonding portion 131. Furthermore, this embodiment does not require the provision of a flexible portion (see reference numeral 430 in FIG. 3), and therefore can have a relatively simple configuration. In addition, the same effects as those of the first embodiment are achieved.

[0109] In the above-described third embodiment (FIG. 16), an example was shown in which the inner peripheral plate portion 41 was disposed above the outer peripheral plate portion 42 in the Z direction, but as shown in FIG. 23, an example in which the outer peripheral plate portion 42 is disposed above the inner peripheral plate portion 41 in the Z direction is also possible. In this case, each parameter can be designed in the same way as in the first embodiment.

[0110] (Embodiment 4) As shown in FIG. 24, this embodiment is an electrochemical reaction device 1 in which the inner peripheral plate portion 41 and the outer peripheral plate portion 42 of the sealing plate 4 are positioned at positions offset from each other in the Z direction, and a flexible portion 430 is formed in the connecting portion 43.

[0111] The example shown in Figure 24 is an example in which the inner circumferential plate portion 41 is positioned above the outer circumferential plate portion 42, but it can also be an example in which the outer circumferential plate portion 42 is positioned above the inner circumferential plate portion 41, as shown in Figure 25. This embodiment is a combination of Embodiment 1 and Embodiment 3. This embodiment also has the same effects as those of Embodiments 1 and 3.

[0112] (Embodiment 5) 26 , 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.

[0113] The inner peripheral pressing portion 61 is made of an insulating elastic material such as an alumina mat. When the manufacturing method of the second embodiment is employed, the inner peripheral pressing portion 61 is disposed between the inner peripheral plate portion 41 and the separator 14 before forming the flexible portion 430 in the connecting portion 43. After that, the flexible portion 430 is formed in the buckling step described above. The rest is the same as in the first embodiment.

[0114] 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. 27 . Forces in the direction of peeling the inner periphery sealing portion 5 and the sealing plate 4 may occur, for example, during the buckling process described above and during use of the electrochemical reaction device 1. By providing the inner periphery pressing portion 61 as shown in FIG. 26 to resist such forces, the bonding strength of the inner periphery bonding portion 131 can be ensured. In other words, providing the inner periphery pressing portion 61 can also 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.

[0115] (Embodiment 6) 28 , 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 above the second space 122 and the bending portion 430.

[0116] The deflection suppressor 62 is made of an insulating elastic material such as an alumina mat. When the manufacturing method of the second embodiment is employed, 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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; 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 maximum expected stress at an inner peripheral joint (131) where the electrochemical cell and the inner peripheral plate are joined, and at an outer peripheral joint (132) where the frame main body and the outer peripheral plate are joined, is equal to or less than a reference strength which is the lower strength of the inner peripheral joint and the outer peripheral joint; The electrochemical reaction device, wherein the maximum assumed stress is derived from a stress relational expression including the bending rigidity of the sealing plate, the height of the connecting portion in the normal direction (Z) of the electrolyte layer, and the assumed maximum change in length of the connecting portion. [2] The electrochemical reaction device according to [1], wherein the connecting portion has a bending portion (430) that is bent in a convex state in a normal direction of the electrolyte layer. [3] The electrochemical reaction device according to [1] or [2], wherein the outer peripheral plate portion and the inner peripheral plate portion of the sealing plate are arranged so as to be shifted in the normal direction. [4] The electrochemical reaction device according to any one of [1] to [3], wherein the inner peripheral joint portion has an inner peripheral seal portion (5) interposed between the inner peripheral plate portion and the electrochemical cell. [5] The electrochemical reaction device according to [4], further comprising an inner peripheral pressing portion (61) that presses the inner peripheral plate portion toward the inner peripheral seal portion. [6] The electrochemical reaction device according to [2], wherein the flexible portion protrudes toward the support portion, and a flexible portion pressing portion (62) is provided to press the flexible portion toward the support portion. [Explanation of symbols]

[0121] REFERENCE SIGNS LIST 1... electrochemical reaction device, 11... outer peripheral gap, 122... second space, 131... inner peripheral joint, 132... outer peripheral joint, 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; 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 maximum expected stress at an inner peripheral joint (131) where the electrochemical cell and the inner peripheral plate portion are joined, and at an outer peripheral joint (132) where the frame main body portion and the outer peripheral plate portion are joined, is equal to or less than a reference strength which is the lower strength of the inner peripheral joint portion and the strength of the outer peripheral joint portion; The electrochemical reaction device, wherein the maximum assumed stress is derived from a stress relational expression including the bending rigidity of the sealing plate, the height of the connecting portion in the normal direction (Z) of the electrolyte layer, and the assumed maximum change in length of the connecting portion.

2. 2. The electrochemical reaction device according to claim 1, wherein the connecting portion has a bending portion (430) that is bent in a convex state in a normal direction of the electrolyte layer.

3. 3. The electrochemical reaction device according to claim 1, wherein the outer peripheral plate portion and the inner peripheral plate portion of the sealing plate are arranged so as to be shifted from each other in the normal direction.

4. 3. The electrochemical reaction device according to claim 1, wherein the inner peripheral joint portion has an inner peripheral seal portion (5) interposed between the inner peripheral plate portion and the electrochemical cell.

5. 5. The electrochemical reaction device according to claim 4, further comprising an inner peripheral pressing portion (61) for pressing the inner peripheral plate portion toward the inner peripheral seal portion.

6. 3. The electrochemical reaction device according to claim 2, wherein the flexible portion protrudes toward the support portion, and a flexible pressing portion (62) is provided to press the flexible portion toward the support portion.

Images