Method for manufacturing metal-supported electrochemical elements

Abstract

To provide a method for manufacturing a metal support type electrochemical element that is excellent in strength (reliability), durability and performance.SOLUTION: A method for manufacturing a metal support type electrochemical element E that includes at least a metal support 1, an electrode layer 2, an electrolyte layer 4, and a counter electrode layer 6 includes: an electrode layer formation step of forming the electrode layer 2 on the metal support 1; an electrolyte layer formation step of forming the electrolyte layer 4 on the electrode layer 2; and a counter electrode layer formation step of forming the counter electrode layer 6 on the electrolyte layer 4. The method further includes, between the electrolyte layer formation step and the counter electrode layer formation step, an annealing step of annealing the electrolyte layer 4 formed in the electrolyte layer formation step.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a metal-supported electrochemical element. In the law To relate to. [Background technology]

[0002] A conventional method for manufacturing a metal-supported solid oxide fuel cell (SOFC) is known, for example, the method disclosed in Non-Patent Document 1.

[0003] The method disclosed in Non-Patent Document 1 involves first forming an anode electrode layer on a porous metal support obtained by sintering Fe-Cr alloy powder. Then, without heating, an electrolyte layer made of yttria-stabilized zirconia (YSZ) is formed on the anode electrode layer using the aerosol deposition method (AD method). Subsequently, a cathode electrode layer is formed on the electrolyte layer by firing. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Jong-Jin Choi and Dong-Soo Park, “Preparation of Metal-supported SOFC using Low Temperature Ceramic Coating Process”, Proceedings of 11th European SOFC & SOE Forum, A1502, Chapter 09 - Session B15 - 14 / 117- 20 / 117 (1-4 July 2014) [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the method described in Non-Patent Document 1 above resulted in insufficient adhesion strength between the layer formed on top of the electrolyte layer and the electrolyte layer, making it difficult to ensure the strength (reliability) and durability of the electrochemical element.

[0006] This invention was made in view of the above circumstances, and provides a method for manufacturing a metal-supported electrochemical element with excellent strength (reliability), durability, and performance. Law Its purpose is to provide. [Means for solving the problem]

[0007] The characteristic configuration of the method for manufacturing a metal-supported electrochemical element according to the present invention, which achieves the above objective, is as follows: A method for manufacturing a metal-supported electrochemical element comprising at least a metal support, an electrode layer, an electrolyte layer, and a counter electrode layer, An electrode layer forming step of forming the electrode layer on the metal support, An electrolyte layer forming step of forming the electrolyte layer on the electrode layer, The process includes a step of forming a counter electrode layer on the electrolyte layer, Between the electrolyte layer formation step and the counter electrode layer formation step, the electrolyte layer formed in the electrolyte layer formation step is Heat in an atmospheric environment to a temperature between 200°C and 1100°C. The system includes an annealing step, The electrolyte layer formation step is characterized by forming the electrolyte layer by a spray coating method in which an aerosolized electrolyte layer material is sprayed.

[0008] According to the above characteristic configuration, after forming the electrolyte layer, the formed electrolyte layer can be annealed, and a counter electrode layer can be formed on top of the annealed electrolyte layer. By annealing the formed electrolyte layer, the surface condition of the electrolyte layer (e.g., water repellency) is improved, and the surface of the electrolyte layer and the components of the counter electrode layer become more compatible. Therefore, the adhesion strength between the electrolyte layer and the counter electrode layer formed on top of it is improved, making it possible to manufacture a metal-supported electrochemical element with excellent strength (reliability), durability, and performance. If the annealing temperature is too high, the metal support may be damaged. Conversely, if the annealing temperature is too low, the surface condition of the electrolyte layer may not be sufficiently improved, and the compatibility between the electrolyte layer surface and the components of the layer formed on top of it may not be sufficient. However, with the above-described characteristic configuration, damage to the metal support due to annealing can be suppressed, and the surface condition of the formed electrolyte layer can be sufficiently improved. As a result, the adhesion strength between the electrolyte layer and the layer formed on top of it can be sufficiently improved, and a metal-supported electrochemical element with excellent strength (reliability), durability, and performance can be manufactured. Furthermore, the electrolyte layer can be formed by a spray coating method that does not require processing in high-temperature ranges (e.g., temperatures above 1100°C) where the metal support may be damaged, thereby suppressing damage to the metal support during electrolyte layer formation. In addition, the electrolyte layer formed by the spray coating method exhibits a greater effect from the surface condition improvement achieved through the annealing treatment.

[0009] Furthermore, a characteristic configuration of another metal-supported electrochemical element manufacturing method of the present invention for achieving the above objective is: A method for manufacturing a metal-supported electrochemical element comprising at least a metal support, an electrode layer, an electrolyte layer, an intermediate layer, and a counter electrode layer, An electrode layer forming step of forming the electrode layer on the metal support, An electrolyte layer forming step of forming the electrolyte layer on the electrode layer, An intermediate layer forming step of forming the intermediate layer on the electrolyte layer, The process includes a step of forming a counter electrode layer on the intermediate layer, Between the electrolyte layer formation step and the intermediate layer formation step, the electrolyte layer formed in the electrolyte layer formation step is Heat in an atmospheric environment to a temperature between 200°C and 1100°C. The system includes an annealing step, The electrolyte layer formation step is characterized by forming the electrolyte layer by a spray coating method in which an aerosolized electrolyte layer material is sprayed.

[0010] According to the above characteristic configuration, after forming the electrolyte layer, the formed electrolyte layer can be subjected to an annealing treatment, and an intermediate layer can be formed on top of the annealed electrolyte layer. By performing the annealing treatment on the formed electrolyte layer, the surface condition of the electrolyte layer (e.g., water repellency) is improved, and the surface of the electrolyte layer and the components of the intermediate layer become more compatible. Therefore, the adhesion strength between the electrolyte layer and the intermediate layer formed on top of it is improved, making it possible to manufacture a metal-supported electrochemical element with superior strength (reliability), durability, and performance. If the annealing temperature is too high, the metal support may be damaged. Conversely, if the annealing temperature is too low, the surface condition of the electrolyte layer may not be sufficiently improved, and the compatibility between the electrolyte layer surface and the components of the layer formed on top of it may not be sufficient. However, with the above-described characteristic configuration, damage to the metal support due to annealing can be suppressed, and the surface condition of the formed electrolyte layer can be sufficiently improved. As a result, the adhesion strength between the electrolyte layer and the layer formed on top of it can be sufficiently improved, and a metal-supported electrochemical element with excellent strength (reliability), durability, and performance can be manufactured. Further, the electrolyte layer can be formed by a spray coating method that does not require treatment in a high-temperature region where the metal support may be damaged (for example, a temperature region higher than 1100°C), and damage to the metal support during formation of the electrolyte layer can be suppressed. In addition, in the electrolyte layer formed by the spray coating method, a great effect of improving the surface state by the annealing treatment can be obtained.

[0011] A further characteristic configuration of the method for manufacturing a metal-supported electrochemical device according to the present invention is that the intermediate layer contains a mixed conductor.

[0012] According to the above characteristic configuration, since the intermediate layer contains a mixed conductor, a metal-supported electrochemical device capable of exhibiting high electrochemical performance can be realized.

[0019] A further characteristic configuration of the method for manufacturing a metal-supported electrochemical device according to the present invention is that the electrolyte layer forming step is a step of forming the electrolyte layer by any one of aerosol deposition method, aerosol gas deposition method, powder jet deposition method, and particle jet deposition method.

[0020] According to the above characteristic configuration, the electrolyte layer can be formed by any one of aerosol deposition method, aerosol gas deposition method, powder jet deposition method, and particle jet deposition method, which does not require treatment in a high-temperature region where the metal support may be damaged (for example, a temperature region higher than 1100°C), and damage to the metal support during formation of the electrolyte layer can be suppressed. In addition, in the electrolyte layer formed by any of the above methods, a great effect of improving the surface state by the annealing treatment can be obtained. In particular, in the electrolyte layer formed at room temperature by any of the above methods, a great effect of improving the surface state by the annealing treatment can be obtained.

[0021] A further characteristic configuration of the method for manufacturing a metal-supported electrochemical device according to the present invention is that the electrolyte layer contains stabilized zirconia.

[0022] According to the above characteristic configuration, since the electrolyte layer contains stabilized zirconia, it is possible to realize a metal-supported electrochemical element that can exhibit high electrochemical performance even in a relatively high temperature range of 600°C or higher, preferably 650°C or higher.

[0023] Further characteristic features of the method for manufacturing a metal-supported electrochemical element according to the present invention are: The metal support is a metal plate that has been perforated.

[0024] According to the above characteristic configuration, since the metal support is a metal plate with holes, it has an advantage in terms of strength compared to porous metal supports obtained by sintering metal powder, etc. [Brief explanation of the drawing]

[0039] [Figure 1] This figure shows a schematic configuration of a metal-supported electrochemical element according to one embodiment. [Figure 2] This figure shows a schematic configuration of an electrochemical module according to one embodiment. [Figure 3] This figure shows a schematic configuration of an electrochemical apparatus and energy system according to one embodiment. [Figure 4] This is a graph showing the results of a tensile strength test. [Figure 5] This figure shows a schematic configuration of a metal-supported electrochemical element according to another embodiment. [Figure 6] This figure shows a schematic configuration of an electrochemical apparatus and energy system according to a different embodiment. [Figure 7] This figure shows a schematic configuration of an electrochemical module according to another embodiment. [Modes for carrying out the invention]

[0040] The following describes the metal-supported electrochemical element E, a method for manufacturing the metal-supported electrochemical element E, a solid oxide fuel cell (SOFC), an electrochemical module M, an electrochemical device Y, and an energy system Z according to this embodiment. In this embodiment, the metal-supported electrochemical element E is used as a component of a solid oxide fuel cell that generates electricity by receiving a fuel gas containing hydrogen and air (oxidizer gas). In the following, when describing the positional relationship of layers, for example, the side of the counter electrode layer 6 as viewed from the electrolyte layer 4 may be referred to as "upper" or "upper side," and the side of the electrode layer 2 may be referred to as "lower" or "lower side." Also, the side of the metal support 1 on which the electrode layer 2 is formed may be referred to as the "front side," and the opposite side may be referred to as the "back side."

[0041] (Metal-supported electrochemical element) As shown in Figure 1, the metal-supported electrochemical element E comprises a metal support 1, an electrode layer 2, a buffer layer 3 formed on the electrode layer 2, an electrolyte layer 4 formed on the buffer layer 3, an intermediate layer 5 formed on the electrolyte layer 4, and a counter electrode layer 6 formed on the intermediate layer 5. In other words, the counter electrode layer 6 is formed on the electrolyte layer 4, and the intermediate layer 5 is formed between the electrolyte layer 4 and the counter electrode layer 6. The electrode layer 2 is porous, and the electrolyte layer 4 is dense.

[0042] (metal support) The metal support 1 maintains the strength of the metal-supported electrochemical element E by supporting the electrode layer 2, buffer layer 3, electrolyte layer 4, intermediate layer 5, and counter electrode layer 6. In other words, the metal support 1 plays the role of a support for the components of the electrochemical element.

[0043] As the material for the metal support 1, a material with excellent electronic conductivity, heat resistance, oxidation resistance, and corrosion resistance is used. For example, ferritic stainless steel, austenitic stainless steel, nickel-based alloys, etc., can be used. In particular, alloys containing chromium are preferably used. In this embodiment, the metal support 1 uses an Fe-Cr alloy containing 18% to 25% by mass of Cr, but it is especially preferable to use an Fe-Cr alloy containing 0.05% or more by mass of Mn, an Fe-Cr alloy containing 0.15% to 1.0% by mass of Ti, an Fe-Cr alloy containing 0.15% to 1.0% by mass of Zr, an Fe-Cr alloy containing Ti and Zr with a total Ti and Zr content of 0.15% to 1.0% by mass, or an Fe-Cr alloy containing 0.10% to 1.0% by mass of Cu. Furthermore, it is preferable that the metal support 1 be made of ferritic stainless steel, as this allows for the realization of an inexpensive and high-strength metal-supported electrochemical element.

[0044] The metal support 1 is plate-shaped overall. The metal support 1 only needs to have sufficient strength to form a metal-supported electrochemical element E as a support. From the viewpoint of ensuring strength, its thickness is preferably 0.1 mm or more, more preferably 0.15 mm or more, and even more preferably 0.2 mm or more. From the viewpoint of suppressing costs, its thickness is preferably 2 mm or less, more preferably 1 mm or less, and even more preferably 0.5 mm or less. The metal support 1 has a plurality of through holes 1a that penetrate from the surface on which the electrode layer 2 is provided (the front surface) to the back surface. In this embodiment, the metal support 1 is a metal plate with a plurality of through holes 1a provided by mechanical, chemical, or optical perforation (hole processing) such as punching, etching, or laser processing, so as to penetrate the front surface and the back surface of the metal plate. This allows for a smooth supply of fuel gas and air from the back surface of the metal support 1 to the electrode layer 2 side, thereby realizing a high-performance metal-supported electrochemical element. Furthermore, the plate-shaped metal support 1 can be bent or otherwise deformed into shapes such as a box or cylinder for use.

[0045] A metal oxide layer 1b is provided on the surface of the metal support 1 as a diffusion-inhibiting layer. That is, a diffusion-inhibiting layer is formed between the metal support 1 and the electrode layer 2, which will be described later. The metal oxide layer 1b is provided not only on the surface of the metal support 1 that is exposed to the outside, but also on the contact surface (interface) with the electrode layer 2 and on the inner surface of the through hole 1a. This metal oxide layer 1b can suppress elemental interdiffusion between the metal support 1 and the electrode layer 2. For example, if ferritic stainless steel containing chromium is used as the metal support 1, the metal oxide layer 1b will mainly consist of chromium oxide. The metal oxide layer 1b, which is mainly composed of chromium oxide, suppresses the diffusion of chromium atoms etc. from the metal support 1 to the electrode layer 2 and electrolyte layer 4. The thickness of the metal oxide layer 1b should be such that it is possible to achieve both high diffusion prevention performance and low electrical resistance. For example, it is preferably on the submicron order, and more preferably the average thickness is about 0.3 μm to 0.7 μm. Furthermore, it is more preferable that the minimum thickness is about 0.1 μm or more. Furthermore, it is preferable that the maximum thickness be approximately 1.1 μm or less.

[0046] The metal oxide layer 1b can be formed by various methods, but a method of oxidizing the surface of the metal support 1 to form a metal oxide is preferably used. Alternatively, the metal oxide layer 1b may be formed on the surface of the metal support 1 by sputtering, PVD methods such as PLD, CVD, spray coating methods (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, and cold spray), or by plating and oxidation treatment. Furthermore, the metal oxide layer 1b may contain a highly conductive spinel phase or the like.

[0047] (electrode layer) As shown in Figure 1, the electrode layer 2 can be provided as a thin layer on the surface of the metal support 1 so as to cover the region in which the through-holes 1a of the metal support 1 are formed. When it is a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably 5 μm to 50 μm. With such a thickness, it is possible to reduce the amount of expensive electrode layer material used and reduce costs while ensuring sufficient electrode performance. Furthermore, the region in the metal support 1 in which the through-holes 1a are provided is entirely covered by the electrode layer 2. In other words, the through-holes 1a are formed inside the region in the metal support 1 in which the electrode layer 2 is formed. In other words, all the through-holes 1a are provided facing the electrode layer 2.

[0048] For the electrode layer 2, composite materials such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO2, and Cu-CeO2 can be used. In these examples, GDC, YSZ, and CeO2 can be referred to as the aggregates of the composite material.

[0049] Furthermore, the electrode layer 2 is preferably formed by low-temperature firing (for example, a wet method using firing in a low temperature range without firing in a high temperature range higher than 1100°C), spray coating (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), PVD (such as sputtering or pulsed laser deposition), or CVD. These processes, which can be used in a low temperature range, allow for the acquisition of a good electrode layer 2 without using firing in a high temperature range higher than 1100°C, for example. Therefore, it is preferable because it does not damage the metal support 1 and suppresses elemental diffusion between the metal support 1 and the electrode layer 2, thereby realizing a durable metal-supported electrochemical element. Moreover, using a low-temperature firing method is even preferable because it simplifies the handling of raw materials.

[0050] The electrode layer 2 has multiple pores on its interior and surface to allow gas permeability. In other words, the electrode layer 2 is formed as a porous layer. For example, the electrode layer 2 is formed so that its density is between 30% and less than 80%. The size of the pores can be appropriately selected to ensure that the electrochemical reaction proceeds smoothly. Density is the ratio of the material constituting the layer to the surrounding space, and can be expressed as (1 - porosity), and is equivalent to relative density.

[0051] (buffer layer) As shown in Figure 1, the buffer layer 3 can be formed as a thin layer on top of the electrode layer 2, covering the electrode layer 2. The buffer layer 3 is positioned between the porous electrode layer 2 and the dense electrolyte layer 4 to form a dense electrolyte layer 4 on top of the porous electrode layer 2, and has a buffering effect that alleviates various stresses that occur during the manufacturing and operation of the metal-supported electrochemical element E. For this reason, the buffer layer 3 is intentionally formed to have a density lower than that of the electrolyte layer 4. Alternatively, the buffer layer 3 may be intentionally formed to have a density higher than that of the electrode layer 2. As a result, even when a porous electrode layer 2 and a dense electrolyte layer 4 are formed on the metal support 1, the buffer layer 3 absorbs and alleviates various stresses between each layer, thereby improving the performance, reliability, and stability of the metal-supported electrochemical element E. When forming a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably about 2 μm to 50 μm, and more preferably about 4 μm to 25 μm. By using this thickness, it becomes possible to reduce the amount of expensive buffer layer material used, thereby lowering costs while ensuring sufficient performance.

[0052] For the buffer layer 3, materials such as YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), and SDC (samarium-doped ceria) can be used. Ceria-based ceramics are particularly preferred.

[0053] The buffer layer 3 is preferably formed by low-temperature firing (for example, a wet method using firing in a low temperature range without firing in a high temperature range higher than 1100°C), spray coating (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), PVD (such as sputtering or pulsed laser deposition), or CVD. These low-temperature film formation processes allow the buffer layer 3 to be obtained without using firing in a high temperature range higher than 1100°C, for example. Therefore, elemental interdiffusion between the metal support 1 and the electrode layer 2 can be suppressed without damaging the metal support 1, and a highly durable metal-supported electrochemical element E can be realized. Furthermore, using a low-temperature firing method is even more preferable because it simplifies the handling of raw materials.

[0054] In this embodiment, the buffer layer 3 is preferably an oxygen ion (oxide ion) conductor, and more preferably a mixed conductor having conductivity for both oxygen ions (oxide ions) and electrons. A buffer layer 3 having such properties is suitable for application to a metal-supported electrochemical element E.

[0055] (electrolyte layer) As shown in Figure 1, the electrolyte layer 4 is formed as a thin layer on the buffer layer 3. It can also be formed as a thin film with a thickness of 10 μm or less. In this embodiment, the electrolyte layer 4 is provided across (straddles) the buffer layer 3 and the metal support 1. By configuring it in this way and bonding the electrolyte layer 4 to the metal support 1, the metal-supported electrochemical element E can be made to have excellent overall robustness.

[0056] Furthermore, the electrolyte layer 4 is provided on the front surface of the metal support 1 in an area larger than the area where the through-hole 1a is provided. In other words, the through-hole 1a is formed inside the area of ​​the metal support 1 where the electrolyte layer 4 is formed. This makes it possible to suppress gas leakage from the electrode layer 2 and buffer layer 3 around the electrolyte layer 4. To explain, when a metal-supported electrochemical element E is used as a component of an SOFC, when the SOFC is in operation, gas is supplied to the electrode layer 2 from the back side of the metal support 1 through the through-hole 1a. In the area where the electrolyte layer 4 is in contact with the metal support 1, gas leakage can be suppressed without providing a separate component such as a gasket. In this embodiment, the electrolyte layer 4 completely covers the periphery of the electrode layer 2, but it is also possible to provide the electrolyte layer 4 on top of the electrode layer 2 and buffer layer 3, and provide a gasket or the like around it.

[0057] As the material for the electrolyte layer 4, electrolyte materials that conduct oxygen ions such as YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), SDC (samarium-doped ceria), and LSGM (strontium-magnesium-doped lanthanum gallate), or electrolyte materials that conduct hydrogen ions such as perovskite-type oxides can be used. In particular, zirconia-based ceramics are preferably used. If the electrolyte layer 4 is made of zirconia-based ceramics, the operating temperature of the SOFC using the metal-supported electrochemical element E can be made higher compared to ceria-based ceramics and various hydrogen ion-conducting materials. For example, in this embodiment, when a metal-supported electrochemical element E is used in an SOFC, if a material capable of exhibiting high electrolyte performance even in high-temperature ranges of approximately 650°C or higher, such as YSZ, is used as the material for the electrolyte layer 4, and hydrocarbon-based fuels such as city gas or LPG are used as the raw fuel for the system, and the raw fuel is converted into the anode gas of the SOFC by steam reforming or the like, a highly efficient SOFC system can be constructed that uses the heat generated in the SOFC cell stack to reform the raw fuel gas. In this embodiment, the electrolyte layer 4 contains stabilized zirconia.

[0058] The electrolyte layer 4 is preferably formed by low-temperature firing (for example, a wet method using firing in a low temperature range without firing in a high temperature range exceeding 1100°C), spray coating (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), PVD (such as sputtering or pulsed laser deposition), or CVD. These film formation processes, usable in low temperature ranges, allow for the creation of a dense, airtight, and highly gas-barrier electrolyte layer 4 without using firing in a high temperature range exceeding 1100°C. This suppresses damage to the metal support 1 and inhibits elemental diffusion between the metal support 1 and the electrode layer 2, enabling the realization of a metal-supported electrochemical element E with excellent performance and durability. In particular, using low-temperature firing or spray coating is preferable because it allows for the realization of a low-cost element. Furthermore, using spray coating is even preferable because a dense, airtight, and highly gas-barrier electrolyte layer can be easily obtained in a low temperature range.

[0059] In this embodiment, the electrolyte layer 4 is formed by the aerosol deposition method, then subjected to an annealing treatment to improve its surface condition, after which the intermediate layer 5, described later, is formed. Therefore, the adhesion strength between the electrolyte layer 4 and the intermediate layer 5 is significantly improved compared to a layer that has not undergone annealing treatment.

[0060] The electrolyte layer 4 is densely constructed to shield against gas leaks of anode and cathode gases and to exhibit high ionic conductivity. The density of the electrolyte layer 4 is preferably 90% or higher, more preferably 95% or higher, and even more preferably 98% or higher. If the electrolyte layer 4 is a uniform layer, its density is preferably 95% or higher, and more preferably 98% or higher. Furthermore, if the electrolyte layer 4 is composed of multiple layers, it is preferable that at least a portion of it includes a layer with a density of 98% or higher (a dense electrolyte layer), and more preferably a layer with a density of 99% or higher (a dense electrolyte layer). This is because including such a dense electrolyte layer as part of the electrolyte layer makes it easier to form a dense electrolyte layer with high airtightness and gas barrier properties, even when the electrolyte layer is composed of multiple layers.

[0061] (Middle class) The intermediate layer 5 can be formed as a thin layer on top of the annealed electrolyte layer 4. When forming a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably about 2 μm to 50 μm, and more preferably about 3 μm to 15 μm. Such a thickness makes it possible to reduce the amount of expensive intermediate layer material used, thereby lowering costs while ensuring sufficient performance.

[0062] In this embodiment, the intermediate layer 5 functions as a reaction-preventing layer. For this reason, the material of the intermediate layer 5 can be any material that can prevent the reaction between the components of the electrolyte layer 4 and the components of the counter electrode layer 6, for example, a ceria-based material can be used. Furthermore, a material containing at least one element selected from the group consisting of Sm, Gd, and Y is preferably used as the material of the intermediate layer 5. It is preferable that it contains at least one element selected from the group consisting of Sm, Gd, and Y, and that the total content of these elements is 1.0% by mass or more and 10% by mass or less. By introducing the intermediate layer 5 as a reaction-preventing layer between the electrolyte layer 4 and the counter electrode layer 6, the reaction between the constituent materials of the counter electrode layer 6 and the constituent materials of the electrolyte layer 4 can be effectively suppressed, and the long-term stability of the performance of the metal-supported electrochemical element E can be improved.

[0063] The intermediate layer 5 preferably has oxygen ion (oxide ion) conductivity. It is even more preferable that it is a mixed conductor having conductivity for both oxygen ions (oxide ions) and electrons. An intermediate layer 5 having such properties is suitable for application to a metal-supported electrochemical element E.

[0064] The formation of the intermediate layer 5 is preferably carried out using a method that can be performed at a processing temperature of 1100°C or lower, as this suppresses damage to the metal support 1 and inhibits elemental diffusion between the metal support 1 and the electrode layer 2, thereby realizing a metal-supported electrochemical element E with excellent performance and durability. For example, this can be done using a low-temperature firing method (e.g., a wet method using firing in a low temperature range without firing in a high temperature range exceeding 1100°C), a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PVD method (such as sputtering or pulsed laser deposition), or a CVD method. In particular, using a low-temperature firing method or a spray coating method is preferable because it enables the realization of a low-cost element. Furthermore, using a low-temperature firing method is even more preferable because it facilitates the handling of raw materials and allows the intermediate layer 5 to be formed with high adhesion strength on the electrolyte layer 4 whose surface condition has been improved by annealing.

[0065] (Counter electrode layer) The counter electrode layer 6 can be formed as a thin layer on the intermediate layer 5. When forming a thin layer, its thickness can be, for example, about 1 μm to 100 μm, preferably 5 μm to 50 μm. Such a thickness makes it possible to reduce the amount of expensive counter electrode layer material used, thereby lowering costs while ensuring sufficient electrode performance.

[0066] As the material for the counter electrode layer 6, for example, composite oxides such as LSCF and LSM, ceria oxides, and mixtures thereof can be used. In particular, it is preferable that the counter electrode layer 6 contains a perovskite-type oxide containing two or more elements selected from the group consisting of La, Sr, Sm, Mn, Co, and Fe. The counter electrode layer 6 constructed using the above materials functions as a cathode.

[0067] Furthermore, it is preferable to form the counter electrode layer 6 using a method that can be performed at a processing temperature of 1100°C or lower, as this suppresses damage to the metal support 1 and inhibits elemental diffusion between the metal support 1 and the electrode layer 2, thereby realizing a metal-supported electrochemical element E with excellent performance and durability. For example, this can be done using a low-temperature firing method (e.g., a wet method using firing in a low temperature range without firing in a high temperature range exceeding 1100°C), a spray coating method (such as thermal spraying, aerosol deposition, aerosol gas deposition, powder jet deposition, particle jet deposition, or cold spray), a PDV method (such as sputtering or pulsed laser deposition), or a CVD method as appropriate. In particular, using a low-temperature firing method or a spray coating method is preferable because it enables the realization of a low-cost element. Moreover, using a low-temperature firing method is even preferable because it facilitates the handling of raw materials and allows for the formation of the counter electrode layer 6 with high adhesion strength.

[0068] (Method for manufacturing metal-supported electrochemical elements) Next, a method for manufacturing the metal-supported electrochemical element E will be described. The method for manufacturing the metal-supported electrochemical element E according to this embodiment includes an electrode layer formation step, an electrolyte layer formation step, an annealing step, an intermediate layer formation step, and a counter electrode layer formation step, and further includes a buffer layer formation step between the electrode layer formation step and the electrolyte layer formation step.

[0069] (Electrode layer formation step) In the electrode layer formation step, the electrode layer 2 is formed as a thin film on the metal support 1. The electrode layer 2 can be formed using the film deposition method described above, but in order to suppress the deterioration of the metal support 1, it is preferable to use a film deposition method that can be used in a low temperature range of 1100°C or less.

[0070] When the electrode layer formation step is performed by a low-temperature firing method, the process is carried out as follows: First, the material powder for electrode layer 2 and the solvent (dispersion medium) are mixed to create a material paste, which is then applied to the front surface of the metal support 1. Then, electrode layer 2 is compression molded (electrode layer smoothing step) and fired at 1100°C or below (electrode layer firing step). Compression molding of electrode layer 2 can be performed by methods such as CIP (Cold Isostatic Pressing), roll press molding, or RIP (Rubber Isostatic Pressing). Furthermore, firing of electrode layer 2 is preferably performed at a temperature between 800°C and 1100°C. The order of the electrode layer smoothing step and the electrode layer firing step can also be reversed. In this embodiment, since the buffer layer 3 is formed after the electrode layer 2 is formed, the electrode layer smoothing step and the electrode layer firing step may be omitted, or the electrode layer smoothing step and the electrode layer firing step may be included in the buffer layer smoothing step and the buffer layer firing step described later. In addition, the electrode layer smoothing step can be performed by lapping, leveling, cutting and polishing the surface, etc.

[0071] Furthermore, in this embodiment, a metal oxide layer 1b (diffusion suppression layer) is formed on the surface of the metal support 1 during the firing process in the electrode layer formation step. In other words, in this embodiment, the firing process includes a firing process in which the firing atmosphere is set to an atmosphere with a low oxygen partial pressure. This results in the formation of a high-quality metal oxide layer 1b with a high effect of suppressing the mutual diffusion of elements and a low resistance value. It should be noted that a separate step for forming the diffusion suppression layer may be performed, including when the electrolyte layer formation step is performed by a method that does not involve firing.

[0072] (Buffer layer formation step) In the buffer layer formation step, a thin buffer layer 3 is formed on the electrode layer 2, covering the electrode layer 2. The buffer layer 3 can be formed using the film deposition method described above, but it is preferable to use a film deposition method that can be used in a low temperature range of 1100°C or less in order to suppress the deterioration of the metal support 1.

[0073] When the buffer layer formation step is performed by low-temperature firing, it is specifically carried out as follows: First, the material powder of the buffer layer 3 and the solvent (dispersion medium) are mixed to prepare a material paste, which is then applied to the front surface of the electrode layer 2. Then the buffer layer 3 is compression molded (buffer layer smoothing step) and fired at 1100°C or below (buffer layer firing step). The compression molding of the buffer layer 3 can be performed by, for example, CIP molding, roll pressure molding, or RIP molding. Furthermore, it is preferable to fire the buffer layer 3 at a temperature between 800°C and 1100°C. This is because at such temperatures, a high-strength buffer layer 3 can be formed while suppressing damage and deterioration of the metal support 1. It is even more preferable to fire the buffer layer 3 at 1050°C or below, and even more preferable to fire it at 1000°C or below. This is because the lower the firing temperature of the buffer layer 3, the more effectively the metal-supported electrochemical element E can be formed while suppressing damage and deterioration of the metal support 1. Furthermore, the order of the buffer layer smoothing process and the buffer layer firing process can be reversed. Also, the buffer layer smoothing process can be performed by methods such as lapping, leveling, or surface cutting and polishing.

[0074] (Electrolyte layer formation step) In the electrolyte layer formation step, the electrolyte layer 4 is formed as a thin layer on top of the buffer layer 3, covering the electrode layer 2 and the buffer layer 3. The electrolyte layer 4 can be formed using the film formation method usable in the low temperature range described above, but it is preferable to use the spray coating method. In particular, in order to form a high-quality electrolyte layer 4 that is dense, airtight and has high gas barrier performance in a temperature range of 1100°C or lower, it is more preferable to use one of the aerosol deposition method, aerosol gas deposition method, powder jet deposition method, or particle jet deposition method. In this embodiment, the electrolyte layer 4 is formed using the aerosol deposition method. Specifically, the aerosolized electrolyte layer 4 material powder (in this embodiment, fine powder of stabilized zirconia such as YSZ or SSZ) is sprayed toward the buffer layer 3 on the metal support 1, and the electrolyte layer 4 is formed at room temperature.

[0075] (Annealing step) In the annealing step, the electrolyte layer 4, which was formed in the electrolyte layer formation step and is not subjected to any further processing such as firing, is annealed at a predetermined processing temperature. This improves the surface condition of the electrolyte layer 4 formed by a spray coating method such as aerosol deposition, and in the intermediate layer formation step described later, forming the intermediate layer 5 on the annealed electrolyte layer 4 improves the adhesion strength between the electrolyte layer 4 and the intermediate layer 5.

[0076] Furthermore, the adhesion strength between the electrolyte layer 4 and the intermediate layer 5 improves with increasing annealing temperature. However, below 200°C, the surface condition improvement effect of the electrolyte layer 4 is insufficient, and the adhesion strength between the electrolyte layer 4 and the intermediate layer 5 tends to be insufficient. To obtain a sufficiently high adhesion strength, it is preferable that the annealing temperature be at least 200°C, and more preferably 500°C or higher. On the other hand, if the annealing temperature is too high, the metal support 1 may be damaged, so it is preferable that the temperature be 1100°C or lower. In this embodiment, the annealing temperatures were set to 200°C, 600°C, and 1000°C.

[0077] (Intermediate layer formation step) In the intermediate layer formation step, a thin intermediate layer 5 is formed on the annealed electrolyte layer 4. The intermediate layer 5 can be formed using the film deposition method described above, but it is preferable to use a film deposition method that can be used in a low temperature range of 1100°C or less in order to suppress the degradation of the metal support 1.

[0078] (Counter electrode layer formation step) In the counter electrode layer formation step, the counter electrode layer 6 is formed as a thin layer on the intermediate layer 5. The counter electrode layer 6 can be formed using the film deposition method described above, but in order to suppress the deterioration of the metal support 1, it is preferable to use a film deposition method that can be used in a low temperature range of 1100°C or less.

[0079] As described above, the adhesion strength between the electrolyte layer 4 and the intermediate layer 5 formed thereon is improved, making it possible to manufacture a metal-supported electrochemical element with superior strength (reliability), durability, and performance.

[0080] (Solid oxide fuel cell) By configuring the metal-supported electrochemical element E as described above, the metal-supported electrochemical element E can be used as a power generation cell in a solid oxide fuel cell. In other words, a solid oxide fuel cell that generates electricity using the metal-supported electrochemical element E can be realized.

[0081] For example, a fuel gas containing hydrogen as the first gas is flowed from the back surface of the metal support 1 through a through hole 1a to the electrode layer 2, and air as the second gas is flowed to the counter electrode layer 6, maintaining a predetermined operating temperature (for example, 500°C to 900°C). In this case, if an electrolyte material that conducts oxygen ions is used in the electrolyte layer 4, the oxygen O2 contained in the air in the counter electrode layer 6 will produce electrons e - It reacts with oxygen ions O 2- This is produced. The oxygen ion O 2- The hydrogen (H2) contained in the circulating fuel gas moves through the electrolyte layer 4 to the electrode layer 2. In the electrode layer 2, the hydrogen (H2) is replaced by oxygen ions (O2). 2- It reacts with water (H2O) and electrons (e). - This is generated.

[0082] When an electrolyte material that conducts hydrogen ions is used for the electrolyte layer 4, hydrogen H2 contained in the fuel gas circulated in the electrode layer 2 loses electrons - to generate hydrogen ions H + . The hydrogen ions H + migrate through the electrolyte layer 4 to the counter electrode layer 6. In the counter electrode layer 6, oxygen O2 contained in air reacts with hydrogen ions H + and electrons e - to generate water H2O.

[0083] Through the above reaction, an electromotive force is generated as an electrochemical output between the electrode layer 2 and the counter electrode layer 6. In this case, the electrode layer 2 functions as a fuel electrode (anode) of the fuel cell, and the counter electrode layer 6 functions as an air electrode (cathode).

[0084] Furthermore, if the solid oxide fuel cell is operable in a temperature range of 650° C. or higher during rated operation, in a fuel system using hydrocarbon-based gas such as city gas as raw fuel, a system can be constructed in which the heat required for converting the raw fuel into hydrogen is covered by the waste heat of the fuel cell, thereby improving the power generation efficiency of the fuel cell system, which is therefore more preferable. Furthermore, if the solid oxide fuel cell is operated in a temperature range of 900° C. or lower during rated operation, the effect of suppressing Cr volatilization from the metal-supported electrochemical element E is enhanced, which is therefore more preferable. If the solid oxide fuel cell is operated in a temperature range of 850° C. or lower during rated operation, the effect of suppressing Cr volatilization is further enhanced, which is therefore even more preferable.

[0085] (Electrochemical Module) Next, the electrochemical module M will be described with reference to Figure 2. The electrochemical module M includes a metal-supported electrochemical element E in which a cylindrical support is formed by a metal support 1 and a U-shaped member 9 attached to the back surface of the metal support 1. Multiple such metal-supported electrochemical elements E are stacked (assembled) with a current collector 26 in between to form the electrochemical module M. In this embodiment, the current collector 26 is joined to the counter electrode layer 6 of the metal-supported electrochemical element E and the U-shaped member 9, electrically connecting the two. However, the counter electrode layer 6 of the metal-supported electrochemical element E and the U-shaped member 9 may be directly electrically connected.

[0086] Furthermore, the electrochemical module M includes a gas manifold 17, a termination member, and a current extraction section. Multiple stacked metal-supported electrochemical elements E have one open end of a cylindrical support connected to the gas manifold 17, and receive a supply of gas from the gas manifold 17. The supplied gas flows through the inside of the cylindrical support and is supplied to the electrode layer 2 through the through-hole 1a of the metal support 1.

[0087] (Electrochemical apparatus and energy systems) Next, with reference to Figure 3, the electrochemical apparatus Y and energy system Z constructed using the electrochemical module M described above will be explained.

[0088] As shown in Figure 3, the energy system Z includes an electrochemical device Y and a heat exchanger 53 which serves as a waste heat utilization unit that reuses the heat circulating from the electrochemical device Y.

[0089] In this embodiment, the electrochemical apparatus Y includes an electrochemical module M, a fuel converter consisting of a desulfurizer 31 and a reformer 34, a fuel supply unit 46 that supplies fuel gas containing the reduced components generated by the fuel converter to the electrochemical module M, and an inverter 38 which is a type of power converter that serves as an output unit for extracting power from the electrochemical module M.

[0090] More specifically, the electrochemical apparatus Y includes a desulfurizer 31, a reformed water tank 32, a vaporizer 33, a reformer 34, a blower 35, a combustion unit 36, an inverter 38, a control unit 39, an electrochemical module M, a storage container 40, and the like.

[0091] The desulfurizer 31 removes (desulfurizes) sulfur compounds contained in hydrocarbon raw fuels such as city gas. When sulfur compounds are present in the raw fuel, the desulfurizer 31 can suppress the effect of sulfur compounds on the reformer 34 or the metal-supported electrochemical element E. The vaporizer 33 generates steam from reformed water supplied from the reformed water tank 32. The reformer 34 uses the steam generated in the vaporizer 33 to steam reform the raw fuel that has been desulfurized in the desulfurizer 31, generating a reformed gas containing hydrogen.

[0092] The electrochemical module M generates electricity by using reformed gas supplied from the reformer 34 and air supplied from the blower 35 to perform an electrochemical reaction. The combustion unit 36 ​​mixes the reaction exhaust gas discharged from the electrochemical module M with air and burns the combustible components in the reaction exhaust gas.

[0093] The electrochemical module M comprises a plurality of metal-supported electrochemical elements E and a gas manifold 17. The plurality of metal-supported electrochemical elements E are arranged in parallel and electrically connected to each other, with one end (lower end) of each metal-supported electrochemical element E fixed to the gas manifold 17. The metal-supported electrochemical elements E generate electricity by causing an electrochemical reaction between the reformed gas supplied through the gas manifold 17 and the air supplied from the blower 35.

[0094] The inverter 38 adjusts the output power of the electrochemical module M to the same voltage and frequency as the power received from the commercial grid (not shown). The control unit 39 controls the operation of the electrochemical apparatus Y and the energy system Z.

[0095] The vaporizer 33, reformer 34, electrochemical module M, and combustion section 36 are housed in a storage container 40. The reformer 34 uses the heat of combustion generated by the combustion of reaction exhaust gas in the combustion section 36 to reform the raw fuel.

[0096] The raw fuel is supplied to the desulfurizer 31 through the raw fuel supply line 42 by the operation of the booster pump 41. The reformed water from the reformed water tank 32 is supplied to the vaporizer 33 through the reformed water supply line 44 by the operation of the reformed water pump 43. The raw fuel supply line 42 then merges with the reformed water supply line 44 downstream of the desulfurizer 31, and the reformed water and raw fuel, which have merged outside the storage container 40, are supplied to the vaporizer 33 located inside the storage container 40.

[0097] The reformed water is vaporized in the vaporizer 33 to become steam. The raw fuel containing the steam generated in the vaporizer 33 is supplied to the reformer 34 through the steam-containing raw fuel supply line 45. In the reformer 34, the raw fuel is steam reformed to produce reformed gas (first gas with reducing properties) mainly composed of hydrogen gas. The reformed gas produced in the reformer 34 is supplied to the gas manifold 17 of the electrochemical module M through the fuel supply unit 46.

[0098] The reformed gas supplied to the gas manifold 17 is distributed to multiple metal-supported electrochemical elements E and supplied to the metal-supported electrochemical elements E from the lower end, which is the connection point between the metal-supported electrochemical elements E and the gas manifold 17. The hydrogen (reducing component) in the reformed gas is mainly used for the electrochemical reaction in the metal-supported electrochemical elements E. The reaction exhaust gas, which includes the remaining hydrogen gas not used in the reaction, is discharged from the upper end of the metal-supported electrochemical elements E to the combustion section 36.

[0099] The reaction exhaust gas is burned in the combustion section 36 and discharged as combustion exhaust gas to the outside of the storage container 40 from the combustion exhaust gas outlet 50. A combustion catalyst section 51 (for example, a platinum-based catalyst) is placed at the combustion exhaust gas outlet 50 to burn and remove reducing components such as carbon monoxide and hydrogen contained in the combustion exhaust gas. The combustion exhaust gas discharged from the combustion exhaust gas outlet 50 is sent to the heat exchanger 53 via the combustion exhaust gas discharge passage 52.

[0100] The heat exchanger 53 exchanges heat between the combustion exhaust gas generated by combustion in the combustion section 36 and the supplied chilled water to produce hot water. In other words, the heat exchanger 53 operates as a waste heat utilization unit that reuses the heat discharged from the electrochemical apparatus Y.

[0101] Alternatively, instead of a waste heat utilization unit, a reaction exhaust gas utilization unit may be provided that utilizes the reaction exhaust gas discharged (without combustion) from the electrochemical module M. The reaction exhaust gas contains residual hydrogen gas that was not used in the reaction in the metal-supported electrochemical element E. In the reaction exhaust gas utilization unit, the residual hydrogen gas is used for heat utilization through combustion or power generation using fuel cells, etc., thereby enabling the efficient use of energy.

[0102] [Example of experiment] The following describes an experimental example. First, a metal support 1 was fabricated by creating multiple through-holes 1a in a circular crofer22APU metal plate with a thickness of 0.3 mm and a diameter of 25 mm using laser processing in a region with a radius of 2.5 mm from the center.

[0103] Next, 60% by mass of NiO powder and 40% by mass of GDC powder were mixed, and an organic binder and an organic solvent (dispersion medium) were added to prepare a paste. Using this paste, an electrode layer 2 was laminated in a region with a radius of 3 mm from the center of the metal support 1. Screen printing was used to form the electrode layer 2. Then, the metal support 1 with the electrode layer 2 laminated was subjected to a firing treatment at 950°C (electrode layer formation step).

[0104] Next, a paste was prepared by adding an organic binder and an organic solvent (dispersion medium) to the fine powder of GDC. Using this paste, a buffer layer 3 was laminated by screen printing in a region with a radius of 5 mm from the center of the metal support 1 on which the electrode layer 2 was laminated. Subsequently, the metal support 1 on which the buffer layer 3 was laminated was subjected to CIP molding at a pressure of 300 MPa, and then fired at 1000°C to form a buffer layer 3 with a flat surface (buffer layer formation step).

[0105] The electrode layer 2 obtained in the above steps had a thickness of approximately 20 μm, and the buffer layer 3 had a thickness of approximately 10 μm. Furthermore, the amount of He leakage from the metal support in this stacked state of electrode layer 2 and buffer layer 3 was approximately 3 mL / min·cm under a pressure of 0.2 MPa. 2 That was the case.

[0106] Next, the electrolyte layer 4 was formed by the aerosol deposition method. Specifically, 8YSZ (yttria-stabilized zirconia) powder with a modal shape of approximately 0.7 μm was aerosolized with dry air at a flow rate of 13 L / min. The aerosol was introduced into a chamber at a pressure of 250 Pa and sprayed onto the metal support 1, which had the electrode layer 2 and buffer layer 3 laminated together, in a 15 mm x 15 mm area so as to cover the buffer layer 3, thereby forming the electrolyte layer 4 at room temperature (electrolyte layer formation step). The metal support 1 was not heated during this process.

[0107] The thickness of the electrolyte layer 4 obtained in the above steps was approximately 3-4 μm. When the amount of He leakage from the metal support 1 with the electrode layer 2, buffer layer 3, and electrolyte layer 4 stacked was measured under a pressure of 0.2 MPa, the amount of He leakage was below the detection limit (1.0 mL / min·cm). 2 The leakage rate was less than ). In other words, the amount of He leakage with the electrolyte layer 4 added was significantly smaller than the amount of He leakage with the buffer layer 3 added, and fell below the detection limit. Therefore, it was confirmed that the formed electrolyte layer 4 was of high quality, dense, and had excellent gas barrier performance.

[0108] Next, the electrolyte layer 4 formed as described above was subjected to an annealing treatment. Specifically, the metal support 1 on which the electrolyte layer 4 was formed was heated in an atmospheric environment at a heating rate of 5°C / min at 600°C or 1000°C for 60 minutes (annealing step).

[0109] Next, a paste was prepared by adding an organic binder and an organic solvent (dispersion medium) to the fine powder of GDC. Using this paste, an intermediate layer 5 was formed on the electrolyte layer 4, which had been annealed as described above, by screen printing. Subsequently, the formed metal-supported electrochemical element E was subjected to a firing treatment at 1000°C to further form the intermediate layer 5 (intermediate layer formation step).

[0110] For the metal-supported electrochemical element E, which was constructed by laminating the electrode layer 2, buffer layer 3, electrolyte layer 4, and intermediate layer 5 obtained in the above steps, the tensile strength was measured using a tensile strength tester to determine the adhesion strength between the electrolyte layer 4 and the intermediate layer 5. Specifically, an Instron universal material tester was used, with an attachment capable of gripping an object attached to its movable tip. After attaching a screw to the upper side of the intermediate layer 5 of the metal-supported electrochemical element E using adhesive, the metal-supported electrochemical element E was fixed to the base of the universal material tester. Then, the screw portion attached to the upper side of the intermediate layer 5 of the metal-supported electrochemical element E was gripped by the aforementioned movable tip attachment. The movable tip was moved vertically upward at a constant speed, and the load required until delamination occurred between the electrolyte layer 4 and the intermediate layer 5 was measured. The area in contact between the adhesive and the intermediate layer 5 was measured using an optical microscope and defined as the measured area. The tensile strength (N / cm²) was calculated by dividing the load required for delamination by the measured area. 2 The following was calculated. As a result, as shown in Figure 4, the adhesion strength between the electrolyte layer 4 and the intermediate layer 5 is approximately 40 N / cm when the annealing treatment is performed at 600°C. 2 In contrast, when performed at 1000°C, the stress was approximately twice as high at 80 N / cm². 2This was the extent of the improvement. From this, it was confirmed that increasing the processing temperature of the annealing treatment increased the adhesion strength between the electrolyte layer 4 and the intermediate layer 5. Although not shown in the figures, when the annealing treatment was performed at 200°C, an improvement in adhesion strength was observed compared to the case without annealing treatment, but the degree of improvement was smaller compared to when it was performed at 600°C.

[0111] [Another embodiment] [1] In the above embodiment, the metal-supported electrochemical element E is provided with an intermediate layer 5, but it is not limited to this, and as shown in Figure 5, the metal-supported electrochemical element E1 may not have an intermediate layer 5. In this case, for example, the metal-supported electrochemical element E has a counter electrode layer 6 formed on the electrolyte layer 4. In this case, the metal-supported electrochemical element E1 can be manufactured by a method that includes at least an electrode layer formation step, an electrolyte layer formation step, an annealing step, and a counter electrode layer formation step, wherein an annealing step is performed between the electrolyte layer formation step and the counter electrode layer formation step to anneal the electrolyte layer 4 formed in the electrolyte layer formation step. In the metal-supported electrochemical element E1 manufactured in this manner, the electrolyte layer 4 is annealed, and the counter electrode layer 6 is formed with an improved surface condition. As a result, the adhesion strength between the electrolyte layer 4 and the counter electrode layer 6 is significantly improved compared to those that have not undergone annealing.

[0112] [2] In the above embodiment, the metal-supported electrochemical element E is provided with a buffer layer 3, but it is not limited to this, and may be provided without a buffer layer 3. In this case, the metal-supported electrochemical element E has an electrolyte layer 4 formed on the electrode layer 2.

[0113] [3] In the above embodiment, the metal support 1 is a metal plate with holes, but it is not limited to this, and may be a porous body obtained by sintering metal powder.

[0114] [4] In the above embodiment, the metal-supported electrochemical element E was used in a solid oxide fuel cell, but this metal-supported electrochemical element E can also be used in solid oxide electrolytic cells, oxygen sensors using solid oxides, and the like. When operating a metal-supported electrochemical element E as an electrolytic cell, a gas containing water vapor or carbon dioxide is passed through the electrode layer 2, and a voltage is applied between the electrode layer 2 and the counter electrode layer 6. This generates electrons e in the electrode layer 2. - It reacts with water (H2O) and carbon dioxide molecules (CO2) to produce hydrogen (H2), carbon monoxide (CO), and oxygen ions (O). 2- This is the result. Oxygen ion O 2- It moves through the electrolyte layer 4 to the counter electrode layer 6. Then, in the counter electrode layer 6, oxygen ions O 2- The electrons are released to form oxygen (O2). Through the above reaction, water (H2O) is electrolyzed into hydrogen (H2) and oxygen (O2). If a gas containing carbon dioxide molecules (CO2) is circulated, it is electrolyzed into carbon monoxide (CO) and oxygen (O2). Figure 6 shows an example of an electrochemical apparatus Y1 and energy system Z1 when a metal-supported electrochemical element E is operated as an electrolytic cell to generate gas by the electrolytic reaction described above. As shown in the figure, the energy system Z1 has an electrochemical apparatus Y1 and two heat exchangers 90 and 92 which serve as waste heat utilization units that reuse the heat circulating from the electrochemical apparatus Y1. In this embodiment, the electrochemical apparatus Y1 includes an electrochemical module M, a fuel converter 91 that synthesizes hydrocarbons based on hydrogen and the like produced in the electrochemical module M, and a power converter 93 that supplies electricity to the electrochemical module M. In this electrochemical apparatus Y1, the electrochemical module M has a plurality of metal-supported electrochemical elements E and two gas manifolds 17 and 171. The plurality of metal-supported electrochemical elements E are arranged in parallel and electrically connected to each other. One end (lower end) of the metal-supported electrochemical element E is fixed to the gas manifold 17, and the other end (upper end) is fixed to the gas manifold 171. The gas manifold 17 at one end of the metal-supported electrochemical element E receives water vapor and carbon dioxide. The hydrogen and carbon monoxide produced by the above-mentioned reaction in the metal-supported electrochemical element E are collected by the gas manifold 171 which is in communication with the other end. Furthermore, in this embodiment, the heat exchanger 90 is configured to operate as a waste heat utilization unit that exchanges heat between the reaction heat generated by the reaction occurring in the fuel converter 91 and water to vaporize it, and the heat exchanger 92 is configured to operate as a waste heat utilization unit that exchanges heat between the waste heat generated by the metal-supported electrochemical element E and water vapor and carbon dioxide to preheat it, thereby increasing energy efficiency. Furthermore, the power converter 93 supplies power to the metal-supported electrochemical element E of the electrochemical module M. As a result, the metal-supported electrochemical element E acts as an electrolytic cell. Therefore, according to the above configuration, an electrochemical apparatus Y1 and energy system Z1 can be realized that can improve the efficiency of converting electrical energy into chemical energy such as fuel.

[0115] [5] In the above embodiment, multiple metal-supported electrochemical elements E are used in combination as an electrochemical module M, but the invention is not limited to this, and they can also be used individually.

[0116] [6] In the above embodiment, the energy systems Z and Z1 are provided with a waste heat utilization unit that reuses the heat discharged from the electrochemical apparatus Y and Y1, but the system is not limited to this, and may be provided without a waste heat utilization unit.

[0117] [7] In the above embodiment, composite materials such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO2, and Cu-CeO2 are used as the material for the electrode layer 2, and composite oxides such as LSCF and LSM are used as the material for the counter electrode layer 6, and hydrogen gas is flowed through the electrode layer 2 to make it a fuel electrode (anode), and air is flowed through the counter electrode layer 6 to make it an air electrode (cathode), and it is used as a power generation cell for a solid oxide fuel cell, but it is not limited to this. The metal-supported electrochemical element E may be configured in such a way that the electrode layer 2 can be an air electrode and the counter electrode layer 6 can be a fuel electrode by changing this configuration. That is, composite oxides such as LSCF and LSM are used as the material for the electrode layer 2, and composite materials such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO2, and Cu-CeO2 are used as the material for the counter electrode layer 6. With a metal-supported electrochemical element E configured in this way, air can be passed through the electrode layer 2 to form an air electrode, and hydrogen gas can be passed through the counter electrode layer 6 to form a fuel electrode, allowing the metal-supported electrochemical element E to be used as a power generation cell for a solid oxide fuel cell.

[0118] [8] In the above embodiment, the electrochemical module M is provided with a metal-supported electrochemical element E in which a cylindrical support is formed by a metal support 1 and a U-shaped member 9 attached to the back surface of the metal support 1, but it is not limited to this. For example, as shown in Figure 7, the electrochemical module M may be configured by stacking metal-supported electrochemical elements E with an inter-cell connecting member 71 in between. In this case, the inter-cell connecting member 71 is a plate-shaped member that is conductive and impermeable to gases, and has grooves 72 that are perpendicular to each other formed on its front and back surfaces. The inter-cell connecting member 71 can be made of a metal such as stainless steel or a metal oxide. When the metal-supported electrochemical elements E are stacked with the cell-to-cell connecting member 71 in between, gas can be supplied to the metal-supported electrochemical elements E through the groove 72. Specifically, the groove 72 formed on one surface becomes the first gas channel 72a, supplying gas to the front side of the metal-supported electrochemical elements E, i.e., the counter electrode layer 6. The groove 72 formed on the other surface becomes the second gas channel 72b, supplying gas to the electrode layer 2 from the back side of the metal-supported electrochemical elements E, i.e., the back side of the metal support 1, through the through hole 1a. When the electrochemical module M configured in this way is operated as a power generation cell of a solid oxide fuel cell, air is supplied to the first gas channel 72a and hydrogen is supplied to the second gas channel 72b. This causes the power generation reaction to proceed in the metal-supported electrochemical element E, generating electromotive force and current. The generated power is extracted to the outside of the electrochemical module M from the cell-to-cell connecting members 71 at both ends of the stacked metal-supported electrochemical element E. Furthermore, the grooves 72 formed on the surface and the grooves formed on the back surface of the inter-cell connecting member 71 may be parallel to each other.

[0119] [9] In the above embodiment, the metal-supported electrochemical element E was mainly used in planar or cylindrical planar solid oxide fuel cells, but it is not limited to this and can also be used in elements such as cylindrical solid oxide fuel cells.

[0120]

[10] In the above embodiment, the electrochemical apparatus Y is provided with an electrochemical module M having a plurality of metal-supported electrochemical elements E, but it is not limited to this. For example, the electrochemical apparatus may be provided with a single metal-supported electrochemical element E.

[0121] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, provided that no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Explanation of Symbols]

[0122] 1: Metal support 2: Electrode layer 3:Buffer layer 4: Electrolyte layer 5: Middle class 6: Counter electrode layer E, E1: Metal-supported electrochemical element M: Electrochemical module Y,Y1: Electrochemical apparatus Z, Z1: Energy System

Claims

1. A method for manufacturing a metal-supported electrochemical element comprising at least a metal support, an electrode layer, an electrolyte layer, and a counter electrode layer, An electrode layer forming step of forming the electrode layer on the metal support, An electrolyte layer forming step of forming the electrolyte layer on the electrode layer, The process includes a step of forming a counter electrode layer on the electrolyte layer, Between the electrolyte layer formation step and the counter electrode layer formation step, there is an annealing step in which the electrolyte layer formed in the electrolyte layer formation step is heated to 200°C to 1100°C in an atmospheric environment to perform an annealing treatment. A method for manufacturing a metal-supported electrochemical element, wherein the electrolyte layer formation step is a step of forming the electrolyte layer by a spray coating method in which an aerosolized electrolyte layer material is sprayed.

2. A method for manufacturing a metal-supported electrochemical element comprising at least a metal support, an electrode layer, an electrolyte layer, an intermediate layer, and a counter electrode layer, An electrode layer forming step of forming the electrode layer on the metal support, An electrolyte layer forming step of forming the electrolyte layer on the electrode layer, An intermediate layer forming step of forming the intermediate layer on the electrolyte layer, The process includes a step of forming a counter electrode layer on the intermediate layer, Between the electrolyte layer formation step and the intermediate layer formation step, there is an annealing step in which the electrolyte layer formed in the electrolyte layer formation step is heated to 200°C to 1100°C in an atmospheric environment to perform an annealing treatment. A method for manufacturing a metal-supported electrochemical element, wherein the electrolyte layer formation step is a step of forming the electrolyte layer by a spray coating method in which an aerosolized electrolyte layer material is sprayed.

3. The method for manufacturing a metal-supported electrochemical element according to claim 2, wherein the intermediate layer contains a mixed conductor.

4. A method for manufacturing a metal-supported electrochemical element according to any one of claims 1 to 3, wherein the electrolyte layer formation step is a step of forming the electrolyte layer by any of the following methods: aerosol deposition, aerosol gas deposition, powder jet deposition, or particle jet deposition.

5. A method for manufacturing a metal-supported electrochemical element according to any one of claims 1 to 4, wherein the electrolyte layer contains stabilized zirconia.

6. A method for manufacturing a metal-supported electrochemical element according to any one of claims 1 to 5, wherein the metal support is a metal plate that has been perforated.

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