Electrochemical device and method for manufacturing same

Abstract

Provided is an electrochemical device that can sufficiently ensure a sealing property and the like. An electrochemical device according to the present embodiment comprises: an electrochemical cell having an electrolyte membrane interposed between a hydrogen electrode and an oxygen electrode; a plurality of separators formed from a metal material; and a gas sealing material for airtightly sealing between the electrochemical cell and the separator and / or between the plurality of separators. In the electrochemical device, a diffusion-preventing coating for preventing the diffusion of a metal element of the metal material constituting the separators covers the surface of the separators. The diffusion-preventing coating is formed from a material that reacts with the material constituting the gas sealing material. Furthermore, a portion at which the separators and the gas sealing material are in direct contact is included.

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to electrochemical devices and methods for making same. [Background technology]

[0002] An electrochemical device is a device related to hydrogen energy, and has an electrochemical cell that is configured with a hydrogen electrode (fuel electrode) and an oxygen electrode (air electrode) sandwiching an electrolyte membrane.

[0003] Electrochemical cells are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, etc. according to the temperature range of use, constituent materials, and type of fuel. Of these, solid oxide electrochemical cells are attracting attention from the viewpoint of efficiency, etc.

[0004] Solid oxide electrochemical cells use a solid oxide as an electrolyte membrane and can be used as solid oxide fuel cells (SOFCs) or solid oxide electrolysis cells (SOECs).

[0005] When a solid oxide electrochemical cell is used as an SOFC, for example, hydrogen supplied to the hydrogen electrode and oxygen (including oxygen in the air) supplied to the oxygen electrode react through an electrolyte membrane under high temperature conditions to generate electric energy. In contrast, when a solid oxide electrochemical cell is used as an SOEC, for example, water (water vapor) is electrolyzed under high temperature conditions to generate hydrogen at the hydrogen electrode and oxygen at the oxygen electrode.

[0006] In general, an electrochemical device is configured with an electrochemical cell stack in which a plurality of electrochemical cells are stacked so as to be electrically connected in series in order to improve output. The electrochemical cell stack includes a plurality of separators. The separators are formed with, for example, a hydrogen flow path and an oxygen flow path. The separators are, for example, electrically conductive, and electrically connect the stacked electrochemical cells. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication 2018-170109 [Patent Document 2] Patent Publication 2019-185883 Summary of the Invention [Problem to be solved by the invention]

[0008] [A] Configuration FIG. 7 is a cross-sectional view showing an example of an electrochemical device according to a related art.

[0009] As shown in FIG. 7, an electrochemical device 1J includes an electrochemical cell 10, separators 21, 22, 23, and 24, and gas seal members 31, 32, and 33. The electrochemical device 1J includes an electrochemical cell 10, separators 21, 22, 23, and 24, and gas seal members 31, 32, and 33.

[0010] Although not shown in the figure, the electrochemical device 1J is a flat plate-type electrochemical cell stack, and FIG. 7 shows a portion where one of the multiple electrochemical cells 10 constituting the electrochemical cell stack is provided.

[0011] Each component of the electrochemical device 1J will be described in detail below.

[0012] [A-1] Electrochemical cell 10 7, the electrochemical cell 10 has a support 11, a hydrogen electrode 12, an electrolyte membrane 13, and an oxygen electrode 14, and is configured so that the electrolyte membrane 13 is interposed between the hydrogen electrode 12 and the oxygen electrode 14 on the upper surface of the support 11. The electrochemical cell 10 is of a hydrogen electrode supported type (fuel electrode supported type) and is formed by sequentially stacking the hydrogen electrode 12, the electrolyte membrane 13, and the oxygen electrode 14 on the upper surface of the support 11.

[0013] In the electrochemical cell 10, the support 11 is made of a porous electrical conductor.

[0014] The hydrogen electrode 12 is made of a porous electrical conductor, for example, Ni-YSZ (yttria-stabilized zirconia).

[0015] The electrolyte membrane 13 is denser than the hydrogen electrode 12 and the oxygen electrode 14, and is made of an ion conductor that does not conduct electricity but conducts ions. The electrolyte membrane 13 is, for example, a material that converts oxygen ions (O 2- ) is made of stabilized zirconia, a solid oxide that is permeable to ultraviolet light.

[0016] The oxygen electrode 14 is made of a porous electrical conductor, for example, a perovskite-type oxide.

[0017] [A-2] Separators 21, 22, 23, 24 Separators 21, 22, 23, and 24 are stacked as shown in Fig. 7. That is, separator 22 is stacked above separator 21, separator 23 is stacked above separator 22, and separator 24 is stacked above separator 23. Separators 21, 22, 23, and 24 are formed of, for example, a metal material.

[0018] Of the multiple separators 21, 22, 23, and 24, the separator 21 is a flat plate, and the electrochemical cell 10 is installed in the central portion of the upper surface. The separator 22 is a flat plate including an internal space SP22 penetrating in the stacking direction in the central portion, and the internal space SP22 accommodates the portion of the electrochemical cell 10 where the support 11, the hydrogen electrode 12, and the electrolyte membrane 13 are stacked. The separator 23 is a flat plate (partition plate) including an internal space SP23 penetrating in the stacking direction in the central portion, and the internal space SP23 accommodates the oxygen electrode 14 of the electrochemical cell 10. The separator 24 is a flat plate, and includes a portion where the lower surface of the separator 24 faces the upper surface of the separator 21 via the internal space SP22 of the separator 22 and the internal space SP23 of the separator 23.

[0019] The surfaces of the multiple separators 21, 22, 23, 24 are coated with diffusion-preventing coatings 211, 221, 231, 241, respectively. Here, from the viewpoint of workability, the diffusion-preventing coatings 211, 221, 231, 241 are provided so as to cover all exposed surfaces of the separators 21, 22, 23, 24.

[0020] The diffusion prevention coatings 211, 221, 231, and 241 are provided to prevent the metal elements (such as Cr) of the metal materials constituting the separators 21, 22, 23, and 24 from diffusing and adversely affecting the electrochemical cell 10. Specifically, the diffusion prevention coatings 211, 221, 231, and 241 prevent the metal elements (such as Cr) of the metal materials constituting the separators 21, 22, 23, and 24 from evaporating from the metal surface, which would cause a decrease in the performance of the electrochemical cell 10.

[0021] The diffusion prevention coatings 211, 221, and 231 are formed using a material containing at least one of oxides of Co, Mn, Cu, Ni, and Fe. Here, the diffusion prevention coatings 211, 221, and 231 are formed using oxides such as spinel and perovskite.

[0022] [A-3] Gas seal material 31, 32, 33 7, the gas seals 31, 32, and 33 are plate-shaped bodies made of materials such as glass and mica. The materials constituting the gas seals 31, 32, and 33 must satisfy conditions such as being stable at high operating temperatures (600 to 1000°C), having a thermal expansion coefficient similar to that of the joining material, and being insulating.

[0023] Here, the gas seal materials 31, 32, and 33 are interposed between the multiple stacked separators 21, 22, 23, and 24. Specifically, the gas seal material 31 is interposed between the separator 21 and the separator 22, the gas seal material 32 is interposed between the separator 22 and the separator 23, and the gas seal material 33 is interposed between the separator 23 and the separator 24. The gas seal material 32 is also interposed between the lower surface of the separator 23 and the upper surface of the electrolyte membrane 13 of the electrochemical cell 10. The gas seal materials 31, 32, and 33 seal the spaces between the multiple separators 21, 22, 23, and 24, and electrically insulate the spaces between them.

[0024] [A-4] Gas flow path 40 7, the electrochemical device 1J is formed with a gas flow path 40. The gas flow path 40 is formed in the side of the electrochemical cell 10 so as to penetrate the separators 21, 22, 23, 24 and the gas sealants 31, 32, 33 in the stacking direction.

[0025] The gas flow path 40 is a flow path for hydrogen electrode gas flowing through the hydrogen electrode 12 of the electrochemical cell 10, or a flow path for oxygen electrode gas flowing through the oxygen electrode 14 of the electrochemical cell 10. The hydrogen electrode gas is gas used in the reaction at the hydrogen electrode 12 and gas produced by the reaction at the hydrogen electrode 12. The oxygen electrode gas is gas used in the reaction at the oxygen electrode 14 and gas produced by the reaction at the oxygen electrode 14.

[0026] [B] Assignment As described above, the surfaces of the separators 21, 22, 23, 24 are coated with the diffusion preventing coatings 211, 221, 231, 241. The diffusion preventing coatings 211, 221, 231, 241 include portions that come into contact with the gas seals 31, 32, 33 as shown in FIG.

[0027] Reactions may occur between the materials constituting the diffusion prevention coatings 211, 221, 231, and 241 and the materials constituting the gas seals 31, 32, and 33. For example, reactions may occur in the case of the following materials. Materials constituting the diffusion prevention coating 211, 221, 231, 241: Oxides containing at least one of the elements Co and Mn Material constituting the gas seal materials 31, 32, and 33: A glass seal material containing at least one element of B, Ba, and Si.

[0028] When a reaction occurs between the material constituting the diffusion prevention coatings 211, 221, 231, 241 and the material constituting the gas seals 31, 32, 33, a large number of bubbles may be generated. As a result, the gas seals 31, 32, 33 may deteriorate, and it may be difficult to ensure sufficient sealing performance. In addition, the diffusion prevention coatings 211, 221, 231, 241 may deteriorate, and it may be difficult to sufficiently prevent the diffusion of metal elements (such as Cr) of the metal material constituting the separators 21, 22, 23, 24.

[0029] Therefore, an object of the present invention is to provide an electrochemical device capable of ensuring sufficient sealing properties and the like, and a method for manufacturing the same. [Means for solving the problem]

[0030] The electrochemical device of the embodiment includes an electrochemical cell having an electrolyte membrane interposed between a hydrogen electrode and an oxygen electrode, a plurality of separators made of a metal material, and a gas seal for sealing at least one of the gap between the electrochemical cell and the separator and the gap between the plurality of separators. In the electrochemical device, the surface of the separator is coated with a diffusion prevention coating for preventing diffusion of metal elements of the metal material constituting the separator. The diffusion prevention coating is made of a material that reacts with the material constituting the gas seal, and includes a portion where the separator and the gas seal are in direct contact with each other. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a cross-sectional view showing an example of an electrochemical device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of an electrochemical device according to a second embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of an electrochemical device according to a third embodiment. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a part of the electrochemical device according to the third embodiment. [Figure 5A] FIG. 5A is a cross-sectional view showing a process for producing an electrochemical device according to a third embodiment. [Figure 5B] FIG. 5B is a cross-sectional view showing a process for producing the electrochemical device according to the third embodiment. [Figure 5C] FIG. 5C is a cross-sectional view showing a process for producing the electrochemical device according to the third embodiment. [Figure 5D] FIG. 5D is a cross-sectional view showing a process for producing the electrochemical device according to the third embodiment. [Figure 6A] FIG. 6A is an enlarged cross-sectional view showing a portion of the electrochemical device according to the third embodiment. [Figure 6B] FIG. 6B is an enlarged cross-sectional view showing a portion of the electrochemical device according to the third embodiment. [Figure 7]FIG. 7 is a cross-sectional view showing an example of an electrochemical device according to a related art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] First Embodiment [A] Configuration FIG. 1 is a cross-sectional view showing an example of an electrochemical device according to a first embodiment.

[0033] 1, the electrochemical device 1 of this embodiment differs from the related art (see FIG. 7) in the configuration of some of the separators 21, 22, and 23. In addition, the gas seal material 33a is different from that of the related art. Except for this point and related points, this embodiment is similar to the related art, and therefore, description of overlapping points will be omitted as appropriate.

[0034] In this embodiment, as shown in FIG. 1, the separators 21, 22, and 23 include portions that directly contact the gas seal materials 31 and 32 without the diffusion barrier coatings 211, 221, and 231 interposed therebetween, unlike the related art (see FIG. 7).

[0035] Specifically, separator 21 includes a portion that directly contacts gas seal material 31 without diffusion barrier coating 211. Separator 22 includes a portion that directly contacts gas seal material 31 and gas seal material 32 without diffusion barrier coating 221. Separator 23 includes a portion that directly contacts gas seal material 32 without diffusion barrier coating 231.

[0036] This configuration is produced, for example, by carrying out a process of coating the diffusion preventing coatings 211, 221, 231 in a state in which the portions of the separators 21, 22, 23 that are in direct contact with the gas seals 31, 32 are masked.

[0037] Unlike the related art, the gas seal material 33a is made of a material that does not react with the material that constitutes the diffusion prevention coatings 231 and 241. For example, the gas seal material 33a is made of the following material. Material constituting the gas seal material 33a: Mica

[0038] [B] Summary As described above, in this embodiment, the separators 21, 22, and 23 include portions that directly contact the gas seals 31 and 32 without the diffusion prevention coatings 211, 221, and 231 therebetween. Therefore, in this embodiment, no reaction occurs between the material constituting the diffusion prevention coatings 211, 221, and 231 and the material constituting the gas seals 31 and 32, and no air bubbles are generated. As a result, in this embodiment, the gas seals 31 and 32 do not deteriorate and sufficient sealing performance can be ensured, and the diffusion prevention coatings 211, 221, and 231 do not deteriorate and diffusion of metal elements (such as Cr) of the metal material constituting the separators 21, 22, 23, and 24 can be sufficiently prevented.

[0039] The diffusion prevention coatings 211, 221, and 231 each contain at least one of oxides of Co, Mn, Cu, Ni, and Fe, which can provide a high effect of suppressing Cr diffusion.

[0040] In this embodiment, the gas seal material 33a does not need to be thinned, so the above-mentioned material that is difficult to thin is used. However, if the gas seal material 33a needs to be thinned and is made of the same material as the other gas seal materials 31 and 32, it is preferable to configure the separator 24 to include a portion that directly contacts the gas seal material 33a without the diffusion prevention coatings 211, 221, and 231 interposed therebetween.

[0041] <Second embodiment> [A] Configuration FIG. 2 is a cross-sectional view showing an example of an electrochemical device according to a second embodiment.

[0042] 2, unlike the related art (see FIG. 7), the electrochemical device 1b of this embodiment has reaction prevention layers 311, 321, and 331. Except for this and related points, this embodiment is similar to the related art, and therefore, description of overlapping points will be omitted as appropriate.

[0043] The reaction prevention layers 311 , 321 , 331 are interposed between the diffusion prevention coatings 211 , 221 , 231 , 241 and the gas seal materials 31 , 32 , 33 .

[0044] Specifically, a reaction preventing layer 311 is interposed between the diffusion preventing coating 211 and the gas sealing material 31, and a reaction preventing layer 311 is interposed between the diffusion preventing coating 221 and the gas sealing material 31. A reaction preventing layer 321 is interposed between the diffusion preventing coating 221 and the gas sealing material 32, and a reaction preventing layer 321 is interposed between the diffusion preventing coating 231 and the gas sealing material 32. A reaction preventing layer 331 is interposed between the diffusion preventing coating 231 and the gas sealing material 33, and a reaction preventing layer 331 is interposed between the diffusion preventing coating 241 and the gas sealing material 33.

[0045] The reaction prevention layers 311, 321, and 331 are formed of, for example, alumina in order to prevent reactions between the diffusion prevention coatings 211, 221, and 231 and the gas seal materials 31, 32, and 33.

[0046] The reaction prevention layers 311, 321, and 331 are formed by, for example, calorizing, PVD, or the like. The reaction prevention layers 311, 321, and 331 each have a thickness of, for example, several hundred nm to several tens of μm.

[0047] [B] Summary As described above, in this embodiment, the reaction prevention layers 311, 321, 331 are interposed between the diffusion prevention coatings 211, 221, 231, 241 and the gas seals 31, 32, 33. Therefore, in this embodiment, no reaction occurs between the material constituting the diffusion prevention coatings 211, 221, 231, 241 and the material constituting the gas seals 31, 32, 33, and no air bubbles are generated. As a result, in this embodiment, the gas seals 31, 32, 33 are not deteriorated and sufficient sealing performance can be ensured, and the diffusion prevention coatings 211, 221, 231, 241 are not deteriorated and diffusion of metal elements (such as Cr) of the metal material constituting the separators 21, 22, 23, 24 can be sufficiently prevented.

[0048] <Third embodiment> [A] Configuration FIG. 3 is a cross-sectional view showing an example of an electrochemical device according to a third embodiment.

[0049] As shown in Fig. 3, in the electrochemical device 1c of this embodiment, similarly to the first embodiment (see Fig. 1), the separators 21, 22, and 23 include portions that are in direct contact with the gas seals 31 and 32 without the diffusion prevention coatings 211, 221, and 231 therebetween. However, in the electrochemical device 1c of this embodiment, the shape of the gas seals 31 and 32 is different from that of the first embodiment, as shown in Fig. 3. Except for this point and related points, this embodiment is similar to the first embodiment, and therefore description of overlapping points will be omitted as appropriate.

[0050] Fig. 4 is an enlarged cross-sectional view showing a part of the electrochemical device according to the third embodiment. Fig. 4 shows a region R in Fig. 3 where a gas seal material 31 is provided between separator 21 and separator 22. The portion in Fig. 3 where a gas seal material 32 is provided between separator 22 and separator 23 is the same as in Fig. 4, and therefore illustration and description thereof will be omitted.

[0051] 4, the surface of separator 21 (first separator) is coated with a diffusion-preventing coating 211 (first diffusion-preventing coating), and the surface of separator 22 (second separator) is coated with a diffusion-preventing coating 221 (second diffusion-preventing coating).

[0052] The diffusion-preventing coating 211 has a through hole K211 (first through hole) formed therein in the stacking direction (vertical direction in FIG. 4) in which the separator 21 and the separator 22 are stacked.

[0053] Similarly, the diffusion preventing coating 221 has a through hole K221 (second through hole) formed therein, which penetrates the diffusion preventing coating 211 in the stacking direction in which the separator 21 and the separator 22 are stacked. The through hole K221 is formed to face the through hole K211 in the stacking direction in which the separator 21 and the separator 22 are stacked.

[0054] In this embodiment, the gas seal material 31 is provided inside the through holes K211 and K221. The face of the gas seal material 31 on the separator 21 side (the lower face in FIG. 4) is in direct contact with the surface of the separator 21. The face of the gas seal material 31 on the separator 22 side (the upper face in FIG. 4) is in direct contact with the surface of the separator 22. The face of the gas seal material 31 along the stacking direction (the side face in FIG. 4) is surrounded by the diffusion preventing coating 211 and the diffusion preventing coating 221.

[0055] [B] Manufacturing method Figures 5A to 5D are cross-sectional views showing steps of manufacturing an electrochemical device according to the third embodiment. Similar to Figure 4, Figures 5A to 5D show region R in Figure 3 where gas seal material 31 is provided between separator 21 and separator 22. The portion in Figure 3 where gas seal material 32 is provided between separator 22 and separator 23 is similar to Figures 5A to 5D, and therefore will not be illustrated or described.

[0056] [B-1] Mask layer formation process First, as shown in FIG. 5A, mask layers M211 and M221 are formed.

[0057] Here, a mask layer M211 (first mask layer) is formed in an area where a through hole K211 (see FIG. 4) is formed on the surface of the separator 21. Also, a mask layer M221 (second mask layer) is formed in an area where a through hole K221 (see FIG. 4) is formed on the surface of the separator 22.

[0058] The mask layers M211 and M221 are fabricated by applying a coating film made of the material of the mask layers M211 and M221 to the regions where the mask layers M211 and M221 are to be formed.

[0059] In this embodiment, the mask layers M211 and M221 are formed in the center of the surface where the separator 21 and the separator 22 overlap when the separator 21 and the separator 22 are stacked. The mask layers M211 and M221 are formed to have a width H2 narrower than a width H1 of the surface where the separator 21 and the separator 22 overlap when the separator 21 and the separator 22 are stacked.

[0060] [B-2] Diffusion prevention coating formation process Next, as shown in FIG. 5B, diffusion prevention coatings 211 and 221 are formed.

[0061] Here, the anti-diffusion coating 211 is formed on the surface of the separator 21 on which the mask layer M211 is formed. The anti-diffusion coating 211 is formed so as to cover the surface of the separator 21 other than the portion on which the mask layer M211 is formed. Also, the anti-diffusion coating 221 is formed on the surface of the separator 22 on which the mask layer M221 is formed. The anti-diffusion coating 221 is formed so as to cover the surface of the separator 22 other than the portion on which the mask layer M221 is formed.

[0062] [B-3] Mask layer removal process Next, as shown in FIG. 5C, the mask layers M211 and M221 (see FIG. 5B) are removed.

[0063] Here, the through hole K211 is formed by removing the mask layer M211 (see FIG. 5B) from the surface of the separator 21 on which the diffusion preventing coating 211 is formed. Also, the through hole K221 is formed by removing the mask layer M221 (see FIG. 5B) from the surface of the separator 22 on which the diffusion preventing coating 221 is formed.

[0064] The removal of the mask layers M211, M221 is carried out using a chemical that dissolves the material of the mask layers M211, M221.

[0065] [B-4] Gas seal material forming process Next, as shown in FIG. 5D, the gas seal material 31 is formed.

[0066] Here, the gas seal material 31 is formed inside the through hole K211 so as to include a portion of the gas seal material 31 protruding from the surface of the diffusion preventing coating 211. The gas seal material 31 is formed so as to have a thickness TH equal to the sum of the depth DP1 of the through hole K211 and the depth DP2 of the through hole K221 (TH=DP1+DP2).

[0067] [B-5] Separator lamination process Next, as shown in FIG. 4, separators 21 and 22 are laminated.

[0068] The separator 22 is laminated on the separator 21 so that the gas seal material 31 formed inside the through hole K211 is accommodated in the through hole K211.

[0069] Through the above steps, the electrochemical device 1c of this embodiment is completed.

[0070] [C] Summary As described above, in the electrochemical device 1c of this embodiment, the gas seal material 31 is formed so as to directly contact the surfaces of the separators 21 and 22 inside the through holes K211 and K221. In this embodiment, unlike the first embodiment, the gas seal material 31 is entirely housed in the sealed space formed by the through holes K211 and K221. Even if a reaction occurs between the material constituting the gas seal material 31 and the material constituting the diffusion prevention coatings 211 and 221 and a part of the diffusion prevention coatings 211 and 221 is peeled off, the structure is such that the reaction part is not exposed to the outside air, so that the diffusion of metal elements (such as Cr) of the metal material constituting the separators 21 and 22 can be suppressed.

[0071] As a result, in this embodiment, even if the gas seal material 31 deteriorates, the sealing performance can be sufficiently ensured, and the performance (power generation performance and electrolysis performance) of the electrochemical cell 10 can be exhibited more efficiently than in the above-mentioned embodiment. Furthermore, in this embodiment, even if deterioration occurs due to a reaction of the diffusion prevention coatings 211, 221, the diffusion of metal elements (such as Cr) of the metal material constituting the separators 21, 22 can be sufficiently prevented, and therefore, the deterioration of the performance of the electrochemical cell 10 due to the diffusing metal elements (such as Cr) can be suppressed more effectively than in the above-mentioned embodiment.

[0072] In this embodiment, even if the gas seal material 31 cannot be manufactured in an ideal shape as shown in FIG. 4 due to manufacturing variations or the like, the above-mentioned effects can be sufficiently achieved.

[0073] 6A and 6B are enlarged cross-sectional views showing a part of the electrochemical device according to the third embodiment. Fig. 6A and Fig. 6B show the same part as Fig. 4, Fig. 6A shows a case where the width of the gas seal material 31 is smaller than the width H2 of the through holes K211 and K221, and Fig. 6B shows a case where the width of the gas seal material 31 is larger than the width H2 of the through holes K211 and K221.

[0074] As shown in FIG. 6A, when the width of the gas seal material 31 is smaller than the width H2 of the through holes K211, K221, a gap G is interposed between the side surface of the gas seal material 31 along the stacking direction (vertical direction in the figure) and the inner surface of the through holes K211, K221 along the stacking direction. The surfaces of the separators 21, 22 where the gap G is located are not covered with the diffusion prevention coatings 211, 221. However, since the surfaces of the separators 21, 22 where the gap G is located are exposed to the sealed space formed by the through holes K211 and K221, the metal elements (Cr, etc.) of the metal material constituting the separators 21, 22 do not diffuse into the electrochemical cell 10. As a result, in this embodiment, it is possible to prevent the performance of the electrochemical cell 10 from being reduced by the diffusing metal elements (Cr, etc.).

[0075] 6B, when the width of the gas seal material 31 is larger than the width H2 of the through holes K211, K221, it is considered that the overlapping portion of the diffusion prevention coating 211, 221 and the gas seal material 31 reacts with each other, generating bubbles. However, even if bubbles are generated and a part of the diffusion prevention coating 211, 221 is lost, the reacted portion is located inside the bonding interface and is sealed by the through holes K211, K221 of the diffusion prevention coating 211, 221. Therefore, in this embodiment, it is possible to suppress the diffusion of metal elements (such as Cr) of the metal material constituting the separators 21, 22, and therefore it is possible to prevent the performance of the electrochemical cell 10 from being reduced by the diffusing metal elements (such as Cr).

[0076] Although a detailed description is omitted, the above-mentioned effects can be obtained in the portion where the gas seal material 32 is formed, similarly to the portion where the gas seal material 31 is formed.

[0077] <Other> Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0078] 1: electrochemical device, 1J: electrochemical device, 1b: electrochemical device, 1c: electrochemical device, 10: electrochemical cell, 11: support, 12: hydrogen electrode, 13: electrolyte membrane, 14: oxygen electrode, 21: separator, 22: separator, 23: separator, 24: separator, 31: gas seal material, 32: gas seal material, 33: gas seal material, 33a: gas seal material, 211: diffusion prevention coating, 221: diffusion prevention coating, 231: diffusion prevention coating, 241: diffusion prevention coating, 311: reaction prevention layer, 321: reaction prevention layer, 331: reaction prevention layer, K211: through hole, K221: through hole, M211: mask layer, M221: mask layer, SP22: internal space, SP23: internal space

Claims

1. an electrochemical cell including a hydrogen electrode and an oxygen electrode and an electrolyte membrane interposed between the hydrogen electrode and the oxygen electrode; A plurality of separators formed of a metal material; a gas seal for sealing at least one of between the electrochemical cell and the separator and between the separators; An electrochemical device comprising: a diffusion-preventing coating for preventing diffusion of metal elements of a metal material constituting the separator covers a surface of the separator; the diffusion prevention coating is formed of a material that reacts with a material constituting the gas seal; The separator and the gas seal material are in direct contact with each other. Electrochemical equipment.

2. The separator is A first separator; a second separator laminated on the first separator; Including, The diffusion barrier coating comprises: a first diffusion barrier coating formed on a surface of the first separator; a second diffusion barrier coating formed on a surface of the second separator; Including, The first diffusion barrier coating comprises: a first through hole formed so as to penetrate the first diffusion preventing coating in a stacking direction in which the first separator and the second separator are stacked; having The second diffusion-preventing coating has a second through hole formed to penetrate the second diffusion-preventing coating in the stacking direction and to face the first through hole in the stacking direction. having the gas seal material is formed inside the first through hole and the second through hole so as to be in direct contact with a surface of the first separator and a surface of the second separator, 2. The electrochemical device of claim 1.

3. an electrochemical cell including a hydrogen electrode and an oxygen electrode and an electrolyte membrane interposed between the hydrogen electrode and the oxygen electrode; A plurality of separators formed of a metal material; a gas seal for sealing at least one of between the electrochemical cell and the separator and between the separators; An electrochemical device comprising: a diffusion-preventing coating for preventing diffusion of metal elements of a metal material constituting the separator covers a surface of the separator; the diffusion prevention coating is formed of a material that reacts with a material constituting the gas seal; A reaction prevention layer is interposed between the diffusion prevention coating and the gas seal material to prevent a reaction between the diffusion prevention coating and the gas seal material. Electrochemical equipment.

4. The diffusion prevention coating includes at least one of oxides of Co, Mn, Cu, Ni, and Fe.

4. An electrochemical device according to claim 1.

5. A method for producing the electrochemical device according to claim 2, comprising the steps of: a mask layer forming step of forming a first mask layer in a region on a surface of the first separator where the first through hole is to be formed, and forming a second mask layer in a region on a surface of the second separator where the second through hole is to be formed; a diffusion prevention coating forming step of forming the first diffusion prevention coating on the surface of the first separator on which the first mask layer is formed, and forming the second diffusion prevention coating on the surface of the second separator on which the second mask layer is formed; a mask layer removing step of forming the first through hole by removing the first mask layer from a surface of the first separator on which the first diffusion barrier coating is formed, and forming the second through hole by removing the second mask layer from a surface of the second separator on which the second diffusion barrier coating is formed; a gas seal forming step of forming the gas seal inside the first through hole such that the gas seal includes a portion protruding from a surface of the first diffusion barrier coating; a separator lamination step of laminating the second separator on the first separator such that the gas seal material formed inside the first through hole is accommodated in the second through hole; having A method for manufacturing an electrochemical device.

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