JP7634406B2 - Electrochemical element, electrochemical module, electrochemical device, energy system, solid oxide fuel cell, solid oxide electrolysis cell, and method for manufacturing electrochemical element - Google Patents

Description

The present invention relates to electrochemical elements, electrochemical modules, electrochemical devices, energy systems, solid oxide fuel cells and solid oxide electrolysis cells, and methods for manufacturing electrochemical elements.

Patent Document 1 proposes an electrochemical module that constitutes an electrochemical device such as a fuel cell (electrochemical power generation cell) or an electrolysis cell, which has a structure in which multiple electrochemical elements are stacked. The electrochemical element described in Patent Document 1 has a conductive support having a flow path formed therein, and an electrochemical reaction section in which a fuel electrode layer, an electrolyte layer, and an air electrode layer are stacked in this order on the support.

In the electrochemical module described above, when multiple electrochemical elements are stacked, the electrochemical elements are electrically connected with the conductive support near its outer periphery as the main conductive path.

In addition, the configuration described in Patent Document 2 is also known as a configuration in which multiple electrochemical elements are stacked while being electrically connected.

Patent Document 2 discloses a fuel cell stack including fuel cells each having a solid oxide electrolyte layer, a fuel electrode layer and a separator stacked above the solid oxide electrolyte layer, and an air electrode layer and a separator stacked below the solid oxide electrolyte layer. In this fuel cell stack, a plurality of fuel cells are stacked with the fuel electrode layer and the air electrode layer electrically connected between adjacent fuel cells by a connection part that electrically connects adjacent fuel cells, and a conductive via that penetrates the separator in the stacking direction and electrically connects the connection part and the fuel electrode layer or the air electrode layer.

JP 2016-195029 A International Publication No. 2017/090367

However, when the vicinity of the outer periphery of the conductive support is used as the main conductive path, the conductive resistance inside the electrochemical element becomes relatively large. As a result, in the electrochemical element of a conventional electrochemical module, losses occur in the power generated in the electrochemical reaction section and in the power applied to the electrochemical reaction section, and there is an issue that the performance of the electrochemical element is not fully utilized.

The conductive vias described in Patent Document 2 must penetrate the separator in the stacking direction to electrically connect the fuel electrode layer and the air electrode layer to the connection parts. This results in a complex fuel cell structure, which is difficult to fabricate and increases the manufacturing costs of the fuel cell. In addition, the complex structure of the fuel cell makes it prone to low durability and performance degradation due to breakage, etc.

The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an electrochemical element that allows electrical connection between electrochemical elements with a simpler structure and has higher performance, an electrochemical module that includes this electrochemical element, an electrochemical device, an energy system, a solid oxide fuel cell and a solid oxide electrolysis cell, and a method for manufacturing an electrochemical element.

The electrochemical device according to the present invention for achieving the above object has the following characteristic configuration:
A conductive plate-shaped support having an internal flow path therein;
an electrochemical reaction section including an electrode layer formed on the plate-like support, a counter electrode layer, and an electrolyte layer sandwiched between the electrode layer and the counter electrode layer;
The plate-shaped support has a connection portion formed in the thickness direction of the plate-shaped support to electrically connect the internal flow paths , and the plate-shaped support is composed of at least two conductive members, and the two conductive members have peripheral portions that serve as conductive paths .

According to the above characteristic configuration, the connection portion formed on the plate-shaped support functions as a conductive path, so that the conductive resistance inside the electrochemical element can be reduced compared to the conventional case in which the vicinity of the outer periphery of the conductive support is used as the main conductive path. Therefore, the loss of the power generated in the electrochemical reaction section and the power applied to the electrochemical reaction section can be reduced. In other words, according to the above characteristic configuration, an electrochemical element with higher performance than the conventional one can be realized.
In addition, compared to a case where a conductive via is provided in the plate-like support in a direction perpendicular to the plate-like surface of the plate-like support (a case where a through hole needs to be formed or a conductive member is embedded in the through hole), the structure is simple and easy to fabricate. Therefore, deterioration in durability and deterioration in performance due to use are unlikely to occur, and the manufacturing cost of the electrochemical element can be reduced.
According to the above-mentioned characteristic configuration, the internal flow path can be easily formed by arranging two conductive members facing each other and joining the outer peripheries. Then, the connection part can be easily formed between the internal flow paths by electrically joining the two conductive members. Therefore, the manufacturing cost of the electrochemical element can be reduced.
In addition, since the two conductive members have peripheral portions that function as conductive paths, the connection portions and peripheral portions function as conductive paths, which makes it possible to reduce the conductive resistance inside the electrochemical element and to realize an electrochemical element with higher performance.

A further characteristic configuration of the electrochemical element according to the present invention is
The internal flow path extends in a first direction along the plate-shaped surface of the plate-shaped support, and has a plurality of sub-flow paths extending in the first direction and spaced apart in a second direction intersecting the first direction along the plate-shaped surface of the plate-shaped support.

For example, when the electrochemical element functions as a fuel cell, gas is passed through the internal flow path. At this time, the gas moves along the inner surface of the plate-shaped member, but the gas flows through multiple flow paths in the internal flow path, and thus the gas flows separately along each of the multiple flow paths. In this case, the gas flow resistance differs between the center and the outer periphery of the internal flow path, and there is a possibility that the gas flow speed differs. If such a speed difference occurs, the amount of gas that reaches the electrochemical reaction section also differs, and therefore the efficiency of generating electrochemical output also differs, and there is a risk of problems such as the occurrence of parts that become locally hot or rapidly deteriorate. However, according to the above characteristic configuration, the flow speed of the gas at any multiple points in the flow cross direction that crosses the flow direction of the gas becomes approximately constant, compared to when the gas flows through an internal flow path in which multiple sub-flow paths are not formed, due to the rectification effect of the gas flowing through the multiple sub-flow paths. In other words, the gas flow speed becomes approximately constant at any multiple points including the center and both ends in the flow cross direction. Therefore, the amount of gas flowing through the electrochemical reaction section can be made roughly constant at any multiple points, including the center and both ends in the cross flow direction. This reduces the difference between the parts of the electrochemical reaction section where there is a shortage of gas and the parts where there is an excess of gas, and a uniform reaction field can be formed over a wide area of the electrochemical reaction section. Therefore, when generating electricity in the entire electrochemical element, the power generation efficiency can be improved and the occurrence of the above problems can be suppressed. In addition, when an electrolytic reaction is performed, the reaction can be made to proceed efficiently.

A further characteristic configuration of the electrochemical element according to the present invention is
A plurality of the electrochemical reaction units are provided on the plate-like support,
The point is that the connection portion is formed at at least one location between the plurality of electrochemical reaction portions.

According to the above characteristic configuration, when a single plate-shaped support has multiple electrochemical reaction units, not only the vicinity of the outer periphery of the plate-shaped support but also the connection unit formed between the multiple electrochemical reaction units functions as a conductive path. In other words, a conductive path is formed at a position closer to the multiple electrochemical reaction units than the vicinity of the outer periphery of the plate-shaped support. Therefore, compared to a case where the vicinity of the outer periphery of a conductive support is used as the main conductive path, the conductive resistance inside the electrochemical element can be reduced, and the loss of power generated in the electrochemical reaction units and power applied to the electrochemical reaction units can be suppressed. In other words, according to the above characteristic configuration, an electrochemical element with higher performance than conventional ones can be realized.
Furthermore, when processing is performed between electrochemical reaction sections to form a connection, there are fewer restrictions such as preventing damage to the electrochemical reaction sections, so the connection can be formed by a variety of methods.

A further characteristic configuration of the electrochemical element according to the present invention is
The plate-like support is made of a metal member.

According to the above characteristic configuration, the electrochemical element has components of the electrochemical reaction section, such as an electrode layer, an electrolyte layer, and a counter electrode layer, formed on a plate-like support made of a metal member with excellent strength, so that the components of the electrochemical reaction section, such as the electrode layer, electrolyte layer, and counter electrode layer, can be made thin. Therefore, it is possible to ensure high performance and durability of the electrochemical element while reducing the material cost of the electrochemical element.

A further characteristic configuration of the electrochemical element according to the present invention is
The connection portion is at a point including a conductive member.

According to the above characteristic configuration, even if the flow path diameter of the internal flow path is large in the thickness direction of the plate-shaped support (in other words, even if the distance between the opposing faces in the thickness direction of the plate-shaped support among the inner faces of the plate-shaped support that form the internal flow path is large), a connection part that electrically connects the internal flow paths can be formed using a conductive member.

A further characteristic configuration of the electrochemical element according to the present invention is
At least a part of the surface of the plate-like support is covered with a metal oxide film.

The above characteristic configuration can prevent components such as Cr from diffusing from the plate-shaped support to the electrode layer of the electrochemical reaction section. This can prevent the performance of the electrode layer from deteriorating, and improve the performance and durability of the electrochemical element.

The electrochemical module according to the present invention has the following characteristic configuration:
The electrochemical elements are arranged in a state where a plurality of the electrochemical elements are assembled and electrically connected to each other.

According to the above characteristic configuration, by arranging the electrochemical elements in a state in which multiple electrochemical elements are electrically connected and in a state in which multiple electrochemical elements are grouped together, it is possible to realize a compact, high-performance electrochemical module that is strong and reliable while suppressing material costs and processing costs. Furthermore, for example, when the electrochemical module is operated as a fuel cell, it is possible to obtain a large power generation output.

The electrochemical device according to the present invention has the following characteristic configuration:
The fuel converter has at least the above-mentioned electrochemical element or electrochemical module, and a fuel converter that generates a reducing component to be supplied to the electrochemical element or electrochemical module, or converts a gas containing a reducing component generated in the electrochemical element or electrochemical module.

According to the above characteristic configuration, when the electrochemical element or electrochemical module is operated as a fuel cell, hydrogen can be generated by a fuel converter such as a reformer based on natural gas or the like supplied by using an existing raw fuel supply infrastructure such as city gas, and an electrochemical device having an electrochemical element or electrochemical module with excellent durability, reliability and performance can be realized. In addition, since it becomes easy to construct a system for recycling unused fuel gas circulated from the electrochemical module, a highly efficient electrochemical device can be realized.
On the other hand, when the electrochemical element or electrochemical module is operated as an electrolysis cell, a gas containing water vapor or carbon dioxide is passed through the electrode layer, and a voltage is applied between the electrode layer and the counter electrode layer. Then, in the electrode layer, the electrons e ^- react with the water molecules H ₂ O and the carbon dioxide molecules CO ₂ to become hydrogen molecules H ₂ , carbon monoxide CO, and oxygen ions O ^{2 -} . The generated oxygen ions O ^{2 -} move through the electrolyte layer to the counter electrode layer. Then, in the counter electrode layer, the oxygen ions O ^{2 -} release electrons to become oxygen molecules O _2. By the above reaction, when a gas containing water vapor is passed through, the water molecules H ₂ O are decomposed into hydrogen H ₂ and oxygen O ₂ , and when a gas containing carbon dioxide molecules CO ₂ is passed through, the water molecules H 2 O are electrolyzed into carbon monoxide CO and oxygen O ₂ .
Therefore, when a gas containing water vapor and carbon dioxide molecules _CO2 is circulated, a fuel converter can be provided that synthesizes various compounds such as hydrocarbons from hydrogen and carbon monoxide generated in the electrochemical element or electrochemical module by the above-mentioned electrolysis. This makes it possible to circulate the hydrocarbons generated by the fuel converter to the electrochemical element or electrochemical module, or to extract them from the present system/apparatus and use them as fuel or chemical raw materials separately.

Another characteristic configuration of the electrochemical device according to the present invention is
The present invention is characterized in that it comprises at least the electrochemical element or the electrochemical module, and a power converter that extracts electric power from the electrochemical element or the electrochemical module, or that passes electric power to the electrochemical element or the electrochemical module.

According to the above characteristic configuration, the power converter can extract the power generated by the electrochemical element or electrochemical module, or can circulate the power to the electrochemical element or electrochemical module. As a result, the electrochemical element or electrochemical module acts as a fuel cell or acts as an electrolytic cell as described above. Therefore, according to the above characteristic configuration, an electrochemical device can be realized with improved efficiency in converting chemical energy such as fuel into electrical energy, or converting electrical energy into chemical energy such as fuel. For example, when an inverter is used as the power converter, when the device is operated as a fuel cell, the inverter can boost the voltage or convert direct current into alternating current, which is preferable because it makes it easier to use the electrical output obtained by the electrochemical element or electrochemical module. Also, when the device is operated as an electrolytic cell, it is preferable because it is possible to construct an electrochemical device that can obtain direct current from an alternating current power source and supply direct current power to the electrochemical element or electrochemical module.

The characteristic configuration of the energy system according to the present invention is as follows:
The present invention is characterized in that the power generating device includes at least the electrochemical device and a waste heat utilization section that reuses heat discharged from the electrochemical device.

The above characteristic configuration makes it possible to realize an energy system that is excellent in durability, reliability, and performance, as well as energy efficiency. It is also possible to realize a hybrid system with excellent energy efficiency by combining it with a power generation system that generates electricity by utilizing the combustion heat of unused fuel gas discharged from the electrochemical device.

The solid oxide fuel cell according to the present invention has the following characteristic configuration:
The present invention is characterized in that it comprises the above-mentioned electrochemical element, and causes a power generation reaction in the electrochemical element.

The above characteristic configuration allows the power generation reaction to be carried out as a solid oxide fuel cell equipped with an electrochemical element that is highly durable, reliable, and high performance, making it possible to obtain a highly durable, high-performance solid oxide fuel cell.

The solid oxide electrolysis cell according to the present invention has the following characteristic configuration:
The present invention is characterized in that it comprises the above-mentioned electrochemical element, and causes an electrolytic reaction in the electrochemical element.

The above characteristic configuration allows gas to be generated by electrolytic reaction as a solid oxide electrolysis cell equipped with an electrochemical element or electrochemical module that is highly durable, reliable, and high performance, making it possible to obtain a highly durable, high-performance solid oxide electrolysis cell.

The method for producing an electrochemical device according to the present invention includes the steps of:
A method for producing the electrochemical device, comprising the steps of:
a connection portion forming step of forming the connection portion,
The connection portion forming step includes at least one of a welding step and a firing step.

The above characteristic configuration allows the connection portion to be formed conveniently.

FIG. 1 is a diagram showing a schematic configuration of an electrochemical element. FIG. 2 is a bottom view showing an electrochemical element. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. This is a cross-sectional view taken along the line VV in FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. IX-IX cross-sectional view in FIG. 2 is a cross-sectional view taken along the line XX in FIG. 1. 1. This is a cross-sectional view taken along the line XI-XI in FIG. 1. This is a cross-sectional view taken along the line XII-XII in FIG. 1. This is a cross-sectional view taken along line XIII-XIII in FIG. 1. This is a cross-sectional view taken along line XIV-XIV in FIG. 1. This is a cross-sectional view taken along the line XV-XV in FIG. 1. This is a cross-sectional view taken along the line XVI-XVI in FIG. 1. This is a cross-sectional view taken along the line XVII-XVII in FIG. 1. This is a cross-sectional view taken along line XVIII-XVIII in FIG. 1. This is a cross-sectional view taken along line XIX-XIX in FIG. FIG. 13 is a diagram showing a state in which a connection portion is formed by laser welding. FIG. 2 is an enlarged view of a main portion of the electrochemical element. 11A and 11B are diagrams for explaining a supply structure and a discharge structure. FIG. 2 is a schematic diagram showing an electrochemical module. FIG. 1 is a schematic diagram showing an energy system. FIG. 4 is a cross-sectional view showing an electrochemical element according to another embodiment. FIG. 11 is a schematic diagram showing an energy system according to another embodiment.

The following describes the electrochemical element, electrochemical module, electrochemical device, energy system, solid oxide fuel cell, solid oxide electrolysis cell, and method for manufacturing the electrochemical element according to embodiments of the present invention with reference to the drawings.

When describing the positional relationship of layers, for example, the counter electrode layer side as viewed from the electrolyte layer may be referred to as "top" or "upper side", and the electrode layer side as "bottom" or "lower side". The stacking direction of the electrochemical element is defined as the +Z direction and -Z direction (Z direction), the direction intersecting the Z direction is defined as the +X direction and -X direction (X direction), and the direction intersecting the X direction and Z direction is defined as the +Y direction and -Y direction (Y direction). The XZ plane, XY plane, and YZ plane are roughly perpendicular to each other.

(Electrochemical element)
First, the electrochemical element A will be described. As shown in Figures 1 to 22, the electrochemical element A includes a plate-like support 10 including a first plate-like body 1 (support) made of a conductive material and a second plate-like body 2 also made of a conductive material, and two electrochemical reaction units 3a, 3b formed at an interval on the plate-like support 10. As will be described later, in this embodiment, the electrochemical element A is used as a solid oxide fuel cell (SOFC) that generates electricity by receiving a supply of a fuel gas containing hydrogen and air.

(Plate-shaped support)
Next, the plate-like support 10 will be described with reference to FIGS. 1 to 22. In this embodiment, the plate-like support 10 is a rectangular shape in top view, composed of a first plate-like body 1 and a second plate-like body 2 using a metal member as a conductive member. That is, the plate-like support 10 is composed of a metal member. The plate-like support 10 has an internal flow path A1 formed between the opposing surfaces of the first plate-like body 1 and the second plate-like body 2. In addition, a first through portion 41 is provided on one end side of the longitudinal direction of the plate-like support 10 to form a supply path 4 for flowing one of the first gas or the second gas from the outer side in the surface penetration direction to the internal flow path A1, and a second through portion 51 is provided on the other end side to form a discharge path 5 for flowing the first gas that has flowed through the internal flow path A1 outward in the surface penetration direction of the plate-like support 10.

As shown in Fig. 4, Fig. 9 to Fig. 11, Fig. 17, Fig. 18, etc., a plate-shaped annular spacer 92 with through holes extending from the front to the back is disposed between the first plate-shaped body 1 and the second plate-shaped body 2 in the plate-shaped support body 10. This annular spacer 92 is disposed on one end side (the first through portion 41 side) and the other end side (the second through portion 51 side) of the plate-shaped support body 10. In addition, this annular spacer 92 has a flow path that allows gas to flow from the space inside the through holes to the space outside the annular spacer 92 when sandwiched between the first plate-shaped body 1 and the second plate-shaped body 2.

(First plate-like body)
The first plate-like body 1 supports the electrode layer 31, the electrolyte layer 32, and the counter electrode layer 33 constituting the electrochemical reaction parts 3a and 3b, and plays a role in maintaining the strength of the electrochemical element A. As the material of the first plate-like body 1, a material having excellent electronic conductivity, heat resistance, oxidation resistance, and corrosion resistance is used. For example, ferritic stainless steel, austenitic stainless steel, nickel-based alloys, etc. are used, but are not limited thereto. In particular, an alloy containing chromium is preferably used. In this embodiment, the first plate-like body 1 uses an Fe-Cr alloy containing 18% by mass or more and 25% by mass or less of Cr, but it is preferable that it contains 0.05% by mass or more of Mn and 0.05% by mass or more and 1.0% by mass or less of Ni. In addition, the lower limit of Cu is preferably 0.01% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.20% by mass or more, and the upper limit is preferably 1.0% by mass or less, more preferably 0.9% by mass or less, and even more preferably 0.8% by mass or less. In addition, the lower limit of Ti is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and even more preferably 0.15% by mass or more, and the upper limit is preferably 1.0% by mass or less, more preferably 0.9% by mass or less, and even more preferably 0.8% by mass or less. By using such an Fe-Cr alloy, an alloy member having excellent performance, durability, and corrosion resistance can be used as the first plate-shaped body 1 while suppressing costs.

The first plate-like body 1 is generally plate-like. It has a gas flow-permitting portion 1A having a number of through holes 11 that penetrate the front surface and the back surface (see Figs. 7 to 10, 14 to 18, and 21). In this embodiment, the gas flow-permitting portion 1A is formed in the area where the electrochemical reaction portions 3a and 3b are formed, and the gas flow-permitting portion 1A is not formed in the area where the electrochemical reaction portions 3a and 3b are not formed (the area between the two electrochemical reaction portions 3a and 3b). The through holes 11 can be formed in the first plate-like body 1 by, for example, mechanical, chemical, or optical drilling.

The through holes 11 have the function of allowing gas to pass from the back surface to the front surface of the first plate-like body 1. It is preferable that the gas flow-permitting portion 1A is provided in an area of the first plate-like body 1 that is smaller than the area in which the electrode layer 31 is provided. It is also possible to use a porous metal such as a sintered metal or a foamed metal to give the first plate-like body 1 gas permeability.

As shown in FIG. 21, the first plate-shaped body 1 is provided with a metal oxide layer 12 (metal oxide film) as a diffusion suppression layer on its surface. That is, the diffusion suppression layer is formed between the first plate-shaped body 1 and the electrode layer 31 described later. The metal oxide layer 12 is provided not only on the surface exposed to the outside of the first plate-shaped body 1, but also on the contact surface (interface) with the electrode layer 31. It can also be provided on the inner surface of the through hole 11. This metal oxide layer 12 can suppress interdiffusion of elements between the first plate-shaped body 1 and the electrode layer 31. For example, when ferritic stainless steel containing chromium is used as the first plate-shaped body 1, the metal oxide layer 12 is mainly chromium oxide. The metal oxide layer 12, which is mainly composed of chromium oxide, suppresses the diffusion of chromium atoms, etc. of the first plate-shaped body 1 into the electrode layer 31 and the electrolyte layer 32. The thickness of the metal oxide layer 12 may be any thickness that can achieve both high diffusion prevention performance and low electrical resistance.

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

When ferritic stainless steel is used for the first plate-like body 1, the thermal expansion coefficient is close to that of YSZ (yttria-stabilized zirconia) and GDC (gadolinium-doped ceria, also called CGO), which are the materials for the electrode layer 31 and electrolyte layer 32 described below. Therefore, the electrochemical element A is less likely to be damaged even when temperature cycles of low and high temperatures are repeated. This is preferable because it allows the realization of an electrochemical element A with excellent long-term durability.

(Second plate-like body)
The second plate-like body 2 is formed with a recess 2c that becomes the internal flow path A1, and is integrated with the first plate-like body 1 by welding at the contact portion (hereinafter, referred to as the peripheral portion 1a) between the periphery of the second plate-like body 2 and the periphery of the first plate-like body 1 in a state where the second plate-like body 2 is overlapped with the first plate-like body 1 (see Figs. 3 to 18). Note that, in place of welding, other methods such as adhesion or fitting may be used for integration, and as long as the internal flow path A1 can be formed separately from the outside, the portions other than the peripheral portion 1a may be joined for integration.

The second plate-like body 2 is made of a heat-resistant metal material. It is preferable that the second plate-like body 2 be made of the same metal material as the first plate-like body 1 from the viewpoints of reducing the difference in thermal expansion with the first plate-like body 1 and ensuring the reliability of joining such as welding.

The second plate-like body 2 is closely related to the configuration of the internal flow path A1, so the detailed configuration of the second plate-like body 2 will be described below in relation to the configuration of the internal flow path A1.

(Configuration of the second plate-like body and the internal flow passage)
In this embodiment, the internal flow path A1 has a distribution section A12, a supply adjustment section A14, a supply buffer section A15, a plurality of sub-flow paths A11, a discharge buffer section A16, a discharge adjustment section A17, and a junction section A13 in the flow direction of the first gas (i.e., from the +X direction to the -x direction). The internal flow path A1 has a symmetrical structure on the side where the first through-portion 41 is provided (the supply path 4 side) and the side where the second through-portion 51 is provided (the discharge path 5 side). Note that Figs. 3 to 10 show cross-sectional views of the supply path 4 side. Figs. 11 to 18 show cross-sectional views of the discharge path 5 side.

The distribution section A12 is provided corresponding to each electrochemical element A. The distribution section A12 is provided on the supply path 4 side and is a buffer section for supplying the first gas to each electrochemical element A. The distribution section A12 is provided on the upstream side of the multiple sub-flow paths A11 in the flow direction (X direction) of the first gas. Specifically, the distribution section A12 is formed by processing the second plate-like body 2 so that it is recessed downward in the stacking direction (-Z direction) from the peripheral edge portion 1a. As shown in Figures 1 and 22, the first through portion 41 is located approximately in the center of the distribution section A12 in the flow direction and its intersecting direction (Y direction). In other words, the through holes of the first plate-like body 1 and the second plate-like body 2 that become the first through portion 41 are formed at this position.

In addition, the distribution section A12 is long in the Y direction when viewed from above, as shown in FIG. 1 etc. The length in the Y direction of the distribution section A12 corresponds to the length in the Y direction of the region of multiple sub-flow paths A11 (described below) that are arranged in parallel and spaced apart in the Y direction.

The plurality of sub-flow paths A11 through which the first gas flows extend in a first direction (X direction) along the plate surface of the plate support 10, and extend in the first direction (X direction) at a distance in a second direction (Y direction) intersecting the first direction (X direction) along the plate surface of the plate support 10. Specifically, as shown in FIG. 1 and FIG. 22, the plurality of sub-flow paths A11 extend along the flow direction (X direction) from the vicinity of the supply adjustment section A14 described later to the vicinity of the discharge adjustment section A17. The plurality of sub-flow paths A11 are arranged in parallel at intervals in the Y direction. As shown in FIG. 1, FIG. 2, FIG. 7 to FIG. 10, the second plate-like body 2 has a plurality of sub-flow path forming sections 80 that form each of the plurality of sub-flow paths A11, and a plurality of partition sections 81 that are provided between adjacent sub-flow path forming sections 80 and partition each of the adjacent sub-flow paths A11. As shown in FIG. 14, FIG. 21, etc., the sub-flow passage forming portion 80 is formed in a concave shape having a bottom surface, and the upper surface of the partition portion 81 is located above the bottom surface of the sub-flow passage forming portion 80 in the stacking direction. The upper surface of the partition portion 81 abuts against the lower surface of the first plate-like body 1. This separates each sub-flow passage A11, and the first gas flows through each sub-flow passage A11 along the flow direction.

In this embodiment, as shown in FIG. 22, in the Y direction (the direction intersecting the flow direction), the length L3 of the partition 81 is smaller than the length L4 of the secondary flow path forming portion 80 (L3<L4). When L3<L4, as shown in FIG. 21, etc., the contact area between the upper surface of the partition 81 and the lower surface of the first plate-like body 1 can be reduced. In other words, the space of the secondary flow path A11 facing the first plate-like body 1 in which the gas flow permitting portion 1A is formed can be increased, and the amount of the first gas flowing from the secondary flow path A11 toward the electrochemical reaction portions 3a, 3b can be increased.

As shown in FIG. 1 and FIG. 6 to FIG. 10, the second plate-like body 2 has a supply adjustment section A14 between the distribution section A12 and the multiple sub-flow paths A11 in the direction along the flow direction (X direction). The supply adjustment section A14 temporarily stores the first gas in the distribution section A12 and limits the supply of the first gas from the distribution section A12 to the multiple sub-flow paths A11.

The supply adjustment section A14 has a plurality of supply passages A14a and a plurality of supply blocking sections A14b. The supply passages A14a pass the first gas from the distribution section A12 to the plurality of sub-flow paths A11. The supply blocking sections A14b block the passage of the first gas from the distribution section A12 to the plurality of sub-flow paths A11. As shown in FIG. 6, the upper surface of the supply blocking section A14b is located above the upper surface of the supply passages A14a in the stacking direction and abuts against the lower surface of the first plate-like body 1. Therefore, the first gas in the distribution section A12 is blocked from flowing in the flow direction by the supply blocking section A14b, while flowing in the flow direction through the supply passages A14a and flowing to the plurality of sub-flow paths A11.

In this embodiment, each supply blocking portion A14b is formed in a generally rectangular shape, for example as shown in FIG. 1 or FIG. 22. Each rectangular supply blocking portion A14b is arranged along the Y direction with its long side aligned along the Y direction. A supply passing portion A14a is provided between adjacent supply blocking portions A14b. In other words, the supply passing portion A14a is provided in a section where the short sides of adjacent supply blocking portions A14b face each other.

In addition, in the flow direction (X direction), one of the partitions 81 is arranged to correspond to the supply passage section A14a. In addition, in the flow direction, at least one of the sub-flow paths A11 is arranged to correspond to the supply blocking section A14b. Specifically, in this embodiment, two of the multiple supply blocking sections A14b are provided at positions corresponding to the +Y direction end and the -Y direction end of the distribution section A12, respectively.

Here, the first gas is guided from the distribution section A12 through the supply passage section A14a to the multiple sub-flow paths A11. According to the above configuration, since any of the partitions 81 is arranged corresponding to the supply passage section A14a in the flow direction, the first gas pushed out from the distribution section A12 to the supply passage section A14a collides with the partition section 81 protruding upward in the stacking direction by proceeding along the flow direction. Due to the collision with the partition section 81, the first gas proceeds in a cross direction intersecting with the flow direction. In other words, the first gas flowing from the distribution section A12 through the supply passage section A14a is not immediately introduced into the multiple sub-flow paths A11, but collides with the partition section 81 just before the sub-flow path A11 and proceeds in the cross direction. Furthermore, the first gas that proceeds in the cross direction does not return to the distribution section A12 due to the supply blocking section A14b protruding upward in the stacking direction, and is temporarily stored between the supply adjustment section A14 and the multiple sub-flow paths A11. The first gas is then introduced into the multiple sub-flow paths A11 formed by the multiple sub-flow path forming parts 80 along the extrusion from the distribution part A12. The area where the first gas is temporarily stored between the supply adjustment part A14 and the multiple sub-flow paths A11 is the supply buffer part A15.

In addition, in the flow direction, the supply blocking section A14b is provided corresponding to the first through-hole 41. This makes it possible to prevent the first gas introduced from the first through-hole 41 into the distribution section A12 from immediately moving toward the multiple sub-flow paths A11. Therefore, the first gas can be temporarily stored in the distribution section A12.

22, in the Y direction, the length L2 of the supply blocking portion A14b is greater than the length L1 of the supply passage portion A14a (L2>L1). In addition, it is preferable that the length L1 of the supply passage portion A14a is less than the length L3 of the partition portion 81 (L1<L3). This allows the first gas pushed out from the distribution portion A12 through the supply passage portion A14a to collide with the end portion on the +X direction side of the partition portion 81 and to be temporarily stored in the supply buffer portion A15 described later. The relationship between L1 and L2 is determined, for example, by the amount of the first gas supplied to the distribution portion A12 per unit time, the amount of the first gas to be supplied to the multiple sub-flow paths A11 per unit time, the number of supply blocking portions A14b, the length L3 of the partition portion 81 in the Y direction, the length L4 of the sub-flow paths A11 in the Y direction, etc.

The number, arrangement, and shape of the supply blocking portions A14b and supply passing portions A14a may be any configuration as long as these functions are fulfilled.

In this way, the supply blocking section A14b of the supply adjustment section A14 of the above configuration is provided between the distribution section A12 and the multiple sub-flow paths A11, and serves as a barrier to the flow of the first gas from the distribution section A12 to the multiple sub-flow paths A11. Therefore, the pressure loss of the first gas increases when the first gas flows from the distribution section A12 to the multiple sub-flow paths A11, and the first gas introduced into the distribution section A12 spreads so as to fill the distribution section A12 and is temporarily stored. Therefore, the entire distribution section A12 has a generally uniform pressure (equal pressure). In other words, the differential pressure between the distribution section A12 and each of the multiple sub-flow paths A11 is approximately the same. On top of that, the first gas is supplied from the distribution section A12 to the multiple sub-flow paths A11 through the supply passage section A14a, so that the first gas is supplied to each sub-flow path A11 in a generally uniform pressure state. As a result, the flow distribution (flow velocity, flow rate, pressure, etc.) of the first gas along the flow direction between each sub-flow path A11 becomes generally uniform. In addition, the first gas is divided from the distribution section A12 and flows into multiple sub-flow paths A11. Due to the rectification effect of being divided into multiple flow paths in this way, the flow distribution (flow velocity, flow rate, pressure, etc.) of the first gas is generally constant compared to when the first gas flows through an internal flow path in which multiple flow paths are not formed. This reduces the difference between the parts of the electrochemical reaction sections 3a and 3b where the first gas is insufficient and the parts where the first gas flows in excess, improving the utilization rate of the first gas in the entire electrochemical element A and improving the reaction efficiency of the electrochemical reaction.

Next, the confluence section A13 and the discharge adjustment section A17 will be described. The confluence section A13 and the discharge adjustment section A17 are configured in the same manner as the distribution section A12 and the supply adjustment section A14, respectively. That is, the confluence section A13 is provided on the discharge path 5 side, and is a buffer section for discharging the first gas that has flowed through the multiple sub-flow paths A11. The confluence section A13 is provided downstream of the multiple sub-flow paths A11 of the internal flow path A1 in the flow direction of the first gas. As shown in FIG. 1 and FIG. 22, the second penetration section 51 is located approximately in the center of the confluence section A13 in the flow direction and the crossing direction. That is, the through holes of the first plate-like body 1 and the second plate-like body 2 that become the second penetration section 51 are formed at this position.

In addition, the junction A13 is long in the Y direction when viewed from above, as shown in FIG. 1 etc. The length in the Y direction of the junction A13 corresponds to the length in the Y direction of the region of the multiple sub-flow paths A11 that are arranged in parallel and spaced apart in the Y direction.

As shown in Figures 1, 13, and 15 to 18, the second plate-like body 2 has an exhaust adjustment section A17 between the multiple sub-flow paths A11 and the junction A13 in the direction along the flow direction (X direction). The exhaust adjustment section A17 limits the exhaust of the first gas from the multiple sub-flow paths A11 to the junction A13.

The discharge adjustment section A17 has a plurality of discharge passages A17a and a plurality of discharge blocking sections A17b. The discharge passages A17a allow the first gas to pass from the plurality of sub-flow paths A11 to the junction A13. The discharge blocking sections A17b block the passage of the first gas from the plurality of sub-flow paths A11 to the junction A13. As shown in FIG. 13, the upper surface of the discharge blocking section A17b is located above the upper surface of the discharge passages A17a in the stacking direction and abuts against the lower surface of the first plate-like body 1. Therefore, the first gas in the plurality of sub-flow paths A11 is prevented from passing in the flow direction by the discharge blocking sections A17b, while passing in the flow direction through the discharge passages A17a and flowing to the junction A13.

In this embodiment, the discharge blocking portion A17b is formed in a generally rectangular shape, as shown in, for example, FIG. 1 and FIG. 22, similar to the supply blocking portion A14b. Each rectangular discharge blocking portion A17b is arranged along the Y direction with its long side aligned along the Y direction. A discharge passing portion A17a is provided between adjacent discharge blocking portions A17b. In other words, the discharge passing portion A17a is provided in a section where the short sides of adjacent discharge blocking portions A17b face each other.

In the flow direction, at least one of the multiple sub-flow paths A11 is arranged to correspond to the discharge blocking portion A17b. Also, in the flow direction, one of the multiple partition portions 81 is arranged to correspond to the discharge passing portion A17a.

According to the above configuration, the first gas pushed out from the multiple sub-flow paths A11 travels along the flow direction and collides with the discharge blocking portion A17b protruding upward in the stacking direction. Due to the collision with the discharge blocking portion A17b, the first gas travels in a cross direction that crosses the flow direction. In other words, the first gas flowing from the multiple sub-flow paths A11 is not immediately introduced into the junction A13, but collides with the discharge blocking portion A17b just before the junction A13 and travels in the cross direction. The first gas then passes through the discharge passing portion A17a along the extrusion from the multiple sub-flow paths A11 and is introduced into the junction A13. The area in which the first gas is temporarily stored between the multiple sub-flow paths A11 and the discharge adjustment portion A17 is the discharge buffer portion A16.

In addition, in the flow direction, the discharge prevention section A17b is provided corresponding to the second through-hole 51. This allows the first gas that has flowed through the multiple sub-flow paths A11 to be immediately introduced into the junction A13, and prevents it from being discharged from the second through-hole 51. Therefore, the first gas can be temporarily stored in the multiple sub-flow paths A11.

22, in the Y direction, the length L12 of the discharge blocking portion A17b is greater than the length L11 of the discharge passing portion A17a (L12>L11). In addition, it is preferable that the length L12 of the discharge blocking portion A17b is greater than the length L4 of the secondary flow passage forming portion 80 (L12>L3). This allows the first gas traveling from the multiple secondary flow passages A11 toward the junction A13 to collide with the discharge blocking portion A17b and temporarily store it in the discharge buffer portion A16 described below. The relationship between L11 and L12 is determined, for example, by the amount of the first gas supplied to the multiple secondary flow passages A11 per unit time, the amount of the first gas to be discharged from the junction A13 per unit time, the number of discharge blocking portions A17b, the length L3 of the partition portion 81 in the Y direction, the length L4 of the secondary flow passage A11 in the Y direction, etc.

The number, arrangement, and shape of the discharge blocking portions A17b and the discharge passing portions A17a may be any configuration as long as these functions are fulfilled.

In this way, the discharge blocking section A17b of the discharge adjustment section A17 of the above configuration is provided between the multiple sub-flow paths A11 and the junction A13, and serves as a barrier to the flow of the first gas from the sub-flow paths A11 to the junction A13. Therefore, the pressure loss of the first gas increases when it flows from the multiple sub-flow paths A11 to the junction A13. Therefore, the first gas introduced into the multiple sub-flow paths A11 is not easily introduced into the junction A13 immediately from the multiple sub-flow paths A11, and spreads to fill the multiple sub-flow paths A11. This makes it possible to make the flow distribution (flow speed, flow rate, pressure, etc.) of the first gas along the flow direction between each sub-flow path A11 roughly uniform. In addition, since the first gas spreads to fill the multiple sub-flow paths A11, the electrochemical reaction is sufficiently carried out in the multiple sub-flow paths A11. As a result, the reaction efficiency of the electrochemical reaction can be improved.

As shown in FIG. 21, the second plate-like body 2 in this embodiment has a metal oxide layer 2d (metal oxide film) formed thereon. The metal oxide layer 2d can be formed by various methods, but a method of oxidizing the surface of the second plate-like body 2 to form a metal oxide is preferably used. It may also be formed by the same method as the metal oxide layer 12 formed on the first plate-like body 1. Furthermore, like the metal oxide layer 12, it may contain a highly conductive spinel phase, etc.

As shown in Figures 1 and 19, in this embodiment, between the two electrochemical reaction sections 3a, 3b, the upper surface of each partition 81 in the second plate-like body 2 is joined to the lower surface of the first plate-like body 1 in contact therewith, and five connection parts 7 are formed that electrically connect the internal flow paths A1 in the thickness direction of the plate-like support 10.

The connection portion 7 is formed by performing a connection portion forming process for forming the connection portion 7 during the manufacture of the electrochemical element A, and the connection portion forming process includes at least one of a welding (adhesion) process and a sintering process. In this embodiment, the connection portion 7 is formed by laser welding (adhesion). Specifically, as shown in FIG. 20, a part of the first plate-like body 1 is melted by laser irradiation, and the molten metal N is used to join the first plate-like body 1 to a part of each partition portion 81 in the second plate-like body 2. In FIG. 20, the metal oxide layers 12, 2d formed on both sides of the first plate-like body 1 and the second plate-like body 2 are also formed on both sides of the first plate-like body 1 and the second plate-like body 2 shown in figures other than FIG. 20, but are omitted from the illustration for convenience.

In this way, by forming the connection part 7, the connection part 7 functions as a conductive path when a current flows between the counter electrode layer 33 and the second plate-like body 2. Therefore, if the connection part 7 is not formed, when a current flows between the counter electrode layer 33 and the second plate-like body 2, only the peripheral part 1a where the first plate-like body 1 and the second plate-like body 2 are welded becomes a conductive path, but by the connection part 7 functioning as a conductive path, the conductive resistance inside the electrochemical element A can be reduced compared to when only the peripheral part 1a is a conductive path. In other words, an electrochemical element A with higher performance than conventional ones can be realized.

Furthermore, the connection portion 7 has a simpler structure than when a conductive via is formed. In addition, processes such as forming through holes, which are necessary for forming conductive vias, and filling the through holes with conductive material are not required. Therefore, a decrease in durability and deterioration of performance are unlikely to occur, and the manufacturing costs of the electrochemical element A can be reduced.

(Electrochemical reaction section)
Next, the electrochemical reaction units 3a and 3b will be described with reference to Figures 7 to 10, 14 to 18, and 21. Note that an intermediate layer 34 and a reaction prevention layer 35, which will be described later, are not shown in Figures 7 to 10 and 14 to 18.

(Electrode Layer)
As shown in Figs. 7 to 10, 14 to 18 and 21, the electrode layer 31 can be provided in a thin layer on the front surface of the first plate-like body 1 in a region larger than the region where the through holes 11 are provided. When the electrode layer 31 is a thin layer, the thickness can be, for example, about 1 to 100 µm, preferably 5 to 50 µm. With such a thickness, it is possible to ensure sufficient electrode performance while reducing the amount of expensive electrode layer material used to reduce costs. In addition, the region where the through holes 11 are provided in the first plate-like body 1 is entirely covered with the electrode layer 31. That is, the through holes 11 are formed inside the region where the electrode layer 31 is formed in the first plate-like body 1. In other words, all the through holes 11 are provided facing the electrode layer 31.

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

The material of the electrode layer 31 may be, for example, a composite material such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO ₂ , or Cu-CeO ₂ . In these examples, GDC, YSZ, and CeO ₂ may be called aggregates of the composite material. The electrode layer 31 is preferably formed by a low-temperature firing method (for example, a wet method using a firing process in a low-temperature range without firing in a high-temperature range higher than 1100° C.), a spray coating method (such as a thermal spray method, an aerosol deposition method, an aerosol gas deposition method, a powder jet deposition method, a particle jet deposition method, or a cold spray method), a PVD method (such as a sputtering method or a pulsed laser deposition method), or a CVD method. By using these processes that can be used in a low-temperature range, a good electrode layer 31 can be obtained without firing in a high-temperature range higher than 1100° C. This is preferable because it is possible to realize an electrochemical element A having excellent durability without damaging the first plate-like body 1 and suppressing interdiffusion of elements between the first plate-like body 1 and the electrode layer 31. Furthermore, the use of a low-temperature firing method is even more preferable because it makes it easier to handle the raw materials.

The electrode layer 31 may be configured so that the content ratio, density, and strength of the aggregate of the cermet material increase continuously from the lower side to the upper side of the electrode layer 31. In this case, the electrode layer 31 does not need to have regions that can be clearly distinguished as layers. However, even in this case, it is possible to increase the content ratio, density, strength, etc. of the aggregate of the cermet material in the portion adjacent to the electrolyte layer 32 (upper portion) compared to the portion adjacent to the first plate-like body 1 (lower portion) of the electrode layer 31.

(Middle class)
The intermediate layer 34 can be formed in a thin layer on the electrode layer 31 while covering the electrode layer 31. When the intermediate layer 34 is a thin layer, the thickness can be, for example, about 1 to 100 μm, preferably about 2 to 50 μm, and more preferably about 4 to 25 μm. With such a thickness, it is possible to reduce the amount of expensive material used for the intermediate layer 34, thereby reducing costs, while ensuring sufficient performance. As the material for the intermediate layer 34, for example, YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), SDC (samarium-doped ceria), etc. can be used. In particular, ceria-based ceramics are preferably used.

The intermediate layer 34 is preferably formed by the same method as the electrode layer 31. By using these film formation processes that can be used in the low temperature range, the intermediate layer 34 can be obtained without firing at a high temperature range, for example, above 1100°C. Therefore, it is possible to suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31 without damaging the first plate-like body 1, and it is possible to realize an electrochemical element A with excellent durability. Furthermore, using a low-temperature firing method is even more preferable because it makes it easier to handle the raw materials.

The intermediate layer 34 preferably has oxygen ion (oxide ion) conductivity, and more preferably has mixed conductivity of oxygen ions (oxide ions) and electrons. An intermediate layer 34 having these properties is suitable for application to the electrochemical element A.

(Electrolyte layer)
7 to 10, 14 to 18, and 21, the electrolyte layer 32 is formed in a thin layer state on the intermediate layer 34, covering the electrode layer 31 and the intermediate layer 34. It may also be formed in a thin film state having a thickness of 10 μm or less. More specifically, the electrolyte layer 32 is provided across (straddling) the intermediate layer 34 and the first plate-like body 1. By configuring in this way and joining the electrolyte layer 32 to the first plate-like body 1, the electrochemical element A can be made to have excellent robustness as a whole.

As shown in Figs. 7 and 14, the electrolyte layer 32 is provided on the front surface of the first plate-like body 1 in an area larger than the area in which the through holes 11 are provided. In other words, the through holes 11 are formed inside the area in which the electrolyte layer 32 is formed in the first plate-like body 1.

In addition, gas leakage from the electrode layer 31 and intermediate layer 34 can be suppressed around the electrolyte layer 32. To explain, when the electrochemical element A is used as a component of an SOFC, gas is supplied to the electrode layer 31 through the through hole 11 from the back side of the first plate-like body 1 during operation of the SOFC. In the area where the electrolyte layer 32 contacts the first plate-like body 1, gas leakage can be suppressed without providing a separate member such as a gasket. Note that, although the electrolyte layer 32 covers the entire periphery of the electrode layer 31 in this embodiment, a configuration in which the electrolyte layer 32 is provided on top of the electrode layer 31 and intermediate layer 34 and a gasket or the like is provided around the periphery may also be used.

As the material of the electrolyte layer 32, 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), and electrolyte materials that conduct hydrogen ions, such as perovskite-type oxides, can be used. In particular, zirconia-based ceramics are preferably used. When the electrolyte layer 32 is made of zirconia-based ceramics, the operating temperature of the SOFC using the electrochemical element A can be made higher than that of ceria-based ceramics and various hydrogen ion conductive materials. For example, when electrochemical element A is used in an SOFC, a material that can exhibit high electrolyte performance even at high temperatures of 650°C or higher, such as YSZ, is used as the material for electrolyte layer 32, and a hydrocarbon-based raw fuel such as city gas or LPG is used as the raw fuel for the system. The raw fuel is converted into SOFC anode gas by steam reforming or the like, and a highly efficient SOFC system can be constructed in which the heat generated in the SOFC cell stack is used to reform the raw fuel gas.

The electrolyte layer 32 is preferably formed by the same method as the electrode layer 31. By using these film formation processes that can be used in the low temperature range, a dense electrolyte layer 32 with high airtightness and gas barrier properties can be obtained without using firing at high temperatures, for example, exceeding 1100°C. This makes it possible to suppress damage to the first plate-like body 1 and to suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, thereby realizing an electrochemical element A with excellent performance and durability. In particular, using a low-temperature firing method or a spray coating method is preferable because it allows the realization of a low-cost element. Furthermore, using a spray coating method is even more preferable because it makes it easy to obtain a dense electrolyte layer 32 with high airtightness and gas barrier properties at a low temperature.

The electrolyte layer 32 is densely constructed to prevent gas leakage of the anode gas and the cathode gas and to exhibit high ion conductivity. The density of the electrolyte layer 32 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. When the electrolyte layer 32 is a uniform layer, the density is preferably 95% or more, and more preferably 98% or more. When the electrolyte layer 32 is constructed in a multi-layered structure, it is preferable that at least a part of the layers includes a layer (dense electrolyte layer) having a density of 98% or more, and more preferably includes a layer (dense electrolyte layer) having a density of 99% or more. If such a dense electrolyte layer is included in a part of the electrolyte layer 32, it is easy to form an electrolyte layer 32 that is dense, airtight, and has high gas barrier properties, even when the electrolyte layer 32 is constructed in a multi-layered structure.

(Reaction prevention layer)
21, the reaction prevention layer 35 can be formed in a thin layer state on the electrolyte layer 32. When the reaction prevention layer 35 is formed as a thin layer, the thickness can be, for example, about 1 to 100 μm, preferably about 2 to 50 μm, and more preferably about 3 to 15 μm. With such a thickness, it is possible to reduce the amount of expensive reaction prevention layer material used, thereby reducing costs, while ensuring sufficient performance.

The material of the reaction prevention layer 35 may be any material capable of preventing a reaction between the components of the electrolyte layer 32 and the components of the counter electrode layer 33, and may be, for example, a ceria-based material. In addition, 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 reaction prevention layer 35. It is preferable that the material contains at least one element selected from the group consisting of Sm, Gd, and Y, and that the total content of these elements is 1.0 mass% or more and 10 mass% or less. By introducing the reaction prevention layer 35 between the electrolyte layer 32 and the counter electrode layer 33, the reaction between the constituent material of the counter electrode layer 33 and the constituent material of the electrolyte layer 32 is effectively suppressed, and the long-term stability of the performance of the electrochemical element A can be improved.

The reaction prevention layer 35 is preferably formed using an appropriate method that can be performed at a processing temperature of 1100°C or less, since this can suppress damage to the first plate-like body 1 and also suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, thereby realizing an electrochemical element A with excellent performance and durability. For example, the reaction prevention layer 35 can be formed using an appropriate method similar to that used for forming the electrode layer 31. In particular, it is preferable to use a low-temperature firing method or a spray coating method, since this allows for the realization of a low-cost element. Furthermore, the low-temperature firing method is even more preferable, since it makes it easier to handle the raw materials.

(Counter electrode layer)
7 to 10, 14 to 18, and 21, the counter electrode layer 33 can be formed as a thin layer on the electrolyte layer 32 or the reaction prevention layer 35. When the counter electrode layer 33 is formed as a thin layer, the thickness of the counter electrode layer 33 can be, for example, about 1 to 100 μm, and preferably 5 to 50 μm. With such a thickness, it is possible to reduce the amount of expensive counter electrode layer material used to reduce costs while ensuring sufficient electrode performance.

The counter electrode layer 33 may be made of, for example, a composite oxide such as LSCF or LSM, a ceria-based oxide, or a mixture thereof. In particular, it is preferable that the counter electrode layer 33 contains a perovskite-type oxide containing two or more elements selected from the group consisting of La, Sr, Sm, Mn, Co, and Fe. The counter electrode layer 33 made of the above materials functions as a cathode.

The counter electrode layer 33 is preferably formed using a method that can be performed at a processing temperature of 1100°C or less, since this can suppress damage to the first plate-like body 1 and also suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, thereby realizing an electrochemical element A with excellent performance and durability. For example, the same method as used to form the electrode layer 31 can be used. In particular, low-temperature firing or spray coating is preferable, since it can realize a low-cost element. Furthermore, the low-temperature firing is even more preferable, since it makes it easier to handle the raw materials.

(Solid oxide fuel cell)
By configuring the electrochemical reaction sections 3a and 3b as described above, when the electrochemical element A having the electrochemical reaction sections 3a and 3b is made to function as a fuel cell, the electrochemical element A can be used as a power generation cell of a solid oxide fuel cell. In other words, a solid oxide fuel cell in which a power generation reaction occurs in the electrochemical element A can be realized.

For example, a fuel gas containing hydrogen as a first gas is circulated from the rear surface of the first plate-like body 1 through the through-holes 11 to the electrode layer 31, and air as a second gas is circulated to the counter electrode layer 33, which is the counter electrode of the electrode layer 31, and the operating temperature is maintained at, for example, 500°C to 900°C. Then, when an electrolyte material that conducts oxygen ions is used for the electrolyte layer 32, oxygen _O2 contained in the air reacts with electrons ^e- in the counter electrode layer 33 to generate oxygen ions ^O2- . The oxygen ions ^O2- move through the electrolyte layer 32 to the electrode layer 31. In the electrode layer 31, hydrogen _H2 contained in the circulated fuel gas reacts with the oxygen ions ^O2- to generate water _H2O and electrons ^e- .

When an electrolyte material that conducts hydrogen ions is used for the electrolyte layer 32, hydrogen _H2 contained in the fuel gas flowing through the electrode layer 31 releases electrons ^e- to generate hydrogen ions H ⁺ . The hydrogen ions H ⁺ move through the electrolyte layer 32 to the counter electrode layer 33. In the counter electrode layer 33, oxygen _O2 contained in the air reacts with the hydrogen ions H ⁺ and the electrons ^e- to generate water _H2O .

The above reaction generates an electromotive force as an electrochemical output between the electrode layer 31 and the counter electrode layer 33. In this case, the electrode layer 31 functions as the fuel electrode (anode) of the fuel cell, and the counter electrode layer 33 functions as the air electrode (cathode).

In addition, a solid oxide fuel cell that can be operated at a temperature range of 650°C or higher during rated operation is more preferable because it can be used to construct a fuel system that uses hydrocarbon gas such as city gas as raw fuel, and can use the exhaust heat of the fuel cell to cover the heat required to convert the raw fuel into hydrogen, thereby improving the power generation efficiency of the fuel cell system. In addition, a solid oxide fuel cell that is operated at a temperature range of 900°C or lower during rated operation is more preferable because it enhances the effect of suppressing Cr volatilization from the metal-supported electrochemical element A, and a solid oxide fuel cell that is operated at a temperature range of 850°C or lower during rated operation is even more preferable because it further enhances the effect of suppressing Cr volatilization.

(Electrochemical module)
Next, the electrochemical module M will be described with reference to FIGS.

As shown in FIG. 23, the electrochemical module M has a housing B made of an insulating material that houses multiple electrochemical elements A.

The electrochemical elements A are stacked in the housing B such that the plate-like support 10 constituting one electrochemical element A faces the plate-like support 10 constituting the other electrochemical element A, and the underside of the region forming the sub-channel forming section 80 of the second plate-like body 2 constituting one electrochemical element A is electrically connected to the counter electrode layer 33 of the electrochemical reaction section 3a, 3b constituting the other electrochemical element A. In addition, between the underside of the second plate-like body 2 constituting one electrochemical element A and the upper surface of the first plate-like body 1 constituting the other electrochemical element A, a flow section A2 is formed through which the second gas flows along these two surfaces.

Furthermore, in the multiple electrochemical elements A, a first annular seal portion 42 is interposed between the lower surface of the region where the distribution portion A12 is formed in one electrochemical element A and the upper surface of the region where the first through portion 41 is formed in the first plate-like body 1 of the other electrochemical element A, which separates the first through portion 41 from the through portion A2 in the flow portion A2. In addition, a second annular seal portion 52 is interposed between the lower surface of the region where the junction portion A13 is formed in one electrochemical element A and the upper surface of the region where the second through portion 51 is formed in the first plate-like body 1 of the other electrochemical element A, which separates the second through portion 51 from the through portion A2 in the flow portion A2. As a result, the supply path 4 is formed by the first through portion 41 and the first annular seal portion 42, and the discharge path 5 is formed by the second through portion 51 and the second annular seal portion 52.

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

The electrochemical elements A are sandwiched between a pair of current collectors 91, 82 and housed inside the housing B. An output section 8 (described later) is extended from the current collectors 91, 82 and is connected to an external power supply destination outside the housing B. The current collectors 91, 82 are arranged to hermetically house the electrochemical elements A in the housing B and to function as a buffer for each electrochemical element A.

In this embodiment, the electrochemical module M includes a first gas supply unit 61 that supplies a first gas to the internal flow path A1 from outside the housing B via the supply path 4, a first gas exhaust unit 62 that exhausts the first gas after the reaction, a second gas supply unit 71 that supplies a second gas to the flow section A2 from outside, a second gas exhaust unit 72 that exhausts the second gas after the reaction, and an output unit 8 that obtains an output associated with the electrochemical reaction in the electrochemical reaction units 3a and 3b. The electrochemical module M also includes a distribution chamber 9 in the housing B that distributes the second gas supplied from the second gas supply unit 71 to the flow section A2.

As a result, the electrochemical module M supplies fuel gas (sometimes called the first gas) from the first gas supply unit 61 and air (sometimes called the second gas) from the second gas supply unit 71, so that the fuel gas enters as shown by the dashed arrow in Figure 23, etc., and air enters as shown by the solid arrow.

The fuel gas supplied from the first gas supply unit 61 is guided to the supply path 4 from the first through-hole 41 of the electrochemical element A arranged at the top, and flows through the internal flow paths A1 of all the electrochemical elements A from the supply path 4 partitioned by the first annular seal portion 42. The air supplied from the second gas supply unit 71 flows into the distribution chamber 9 temporarily, and then flows through the flow portion A2 formed between each electrochemical element A. In this embodiment, the flow direction in which the fuel gas flows through the internal flow path A1 along the plane of the plate-shaped support 10 is from the +X direction to the -X direction. Similarly, the flow direction in which the air flows through the flow portion A2 along the plane of the plate-shaped support 10 is from the +X direction to the -X direction.

In some parts of Figure 23, etc., an electrochemical element A in which a cross section including the internal flow path A1 appears and an electrochemical element A in which a cross section including the flow section A2 appears are shown side by side for convenience, but the fuel gas supplied from the first gas supply section 61 reaches the distribution section A12 (see Figures 1, 4, 5, etc.), spreads and flows along the width direction of one end side through the distribution section A12, and reaches each sub-flow path A11 of the internal flow path A1 (see Figures 1, 4, 5, etc.).

The fuel gas flows through the first gas supply section 61, the first annular seal section 42, the first through section 41, etc., and is supplied to the distribution section A12 of each electrochemical element A. The fuel gas supplied to the distribution section A12 is temporarily stored in the distribution section A12 by the supply adjustment section A14. The fuel gas is then introduced from the distribution section A12 into the multiple sub-flow paths A11. The fuel gas that has entered each sub-flow path A11 flows through each sub-flow path A11 and enters the electrode layer 31 and the electrolyte layer 32 through the gas flow allowance section 1A. The fuel gas also proceeds further through the sub-flow path A11 together with the fuel gas that has undergone the electrochemical reaction. The fuel gas that has reached the end of the multiple sub-flow paths A11 in the flow direction proceeds to the confluence section A13 with the flow to the confluence section A13 being partially restricted by the discharge adjustment section A17. The fuel gas that reaches the junction A13 flows through the junction A13, the second through-hole 51, the second annular seal portion 52, etc. Then, together with the fuel gas that has undergone electrochemical reaction from the other electrochemical elements A, it is discharged to the outside from the first gas discharge portion 62.

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

The electric power generated in the electrochemical reaction units 3a, 3b according to the flow of the fuel gas and air is connected in series between the collectors 91, 82 by contact between the counter electrode layer 33 of the electrochemical reaction units 3a, 3b in the adjacent electrochemical element A and the second plate-like body 2, and the composite output is taken out from the output unit 8. As described above, in this embodiment, the connection unit 7 is formed. Therefore, the electric power generated in the multiple electrochemical reaction units 3a, 3b is taken out as a composite output connected in series between the collectors 91, 82 with the peripheral portion 1a, which is the joint between the first plate-like body 1 and the second plate-like body 2, and the connection unit 7 forming a conductive path.

(Electrochemical devices and energy systems)
Next, an electrochemical device 100 and an energy system Z constructed using the electrochemical module M will be described.

Figure 24 shows an overview of the electrochemical device 100 and the energy system Z. As shown in the figure, the energy system Z has the electrochemical device 100 and a heat exchanger 200 as a waste heat utilization section that reuses the heat circulated from the electrochemical device 100.

In this embodiment, the electrochemical device 100 has an electrochemical module M, a fuel converter consisting of a desulfurizer 101 and a reformer 102, a fuel supply unit 103 that circulates fuel gas containing reducing components generated by the fuel converter to the electrochemical module M, and an inverter 104, which is a type of power converter, as an output unit 8 that extracts electricity from the electrochemical module M.

More specifically, the electrochemical device 100 has a desulfurizer 101, a reforming water tank 105, a vaporizer 106, a reformer 102, a blower 107, a combustion section 108, an inverter 104, a control section 110, and an electrochemical module M.

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

The electrochemical module M generates electricity by electrochemically reacting the reformed gas circulated from the reformer 102 with the air circulated from the blower 107. The combustion section 108 mixes the reaction exhaust gas circulated from the electrochemical module M with air and combusts the combustible components in the reaction exhaust gas.

The inverter 104 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 110 controls the operation of the electrochemical device 100 and the energy system Z.

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

The raw fuel is circulated to the desulfurizer 101 through the raw fuel supply passage 112 by the operation of the boost pump 111. The reforming water in the reforming water tank 105 is circulated to the vaporizer 106 through the reforming water supply passage 114 by the operation of the reforming water pump 113. The raw fuel supply passage 112 merges with the reforming water supply passage 114 at a location downstream of the desulfurizer 101, and the reforming water and raw fuel that are merged outside the housing B are circulated to the vaporizer 106.

The reforming water is vaporized in the vaporizer 106 to become water vapor. The raw fuel containing water vapor generated in the vaporizer 106 is circulated to the reformer 102 through the water vapor-containing raw fuel supply passage 115. The raw fuel is steam reformed in the reformer 102 to generate a reformed gas (a first gas having a reducing component) mainly composed of hydrogen gas. The reformed gas generated in the reformer 102 is circulated to the electrochemical module M through the fuel supply unit 103.

The reaction exhaust gas is combusted in the combustion section 108 to become combustion exhaust gas, which is sent from the combustion exhaust gas exhaust passage 116 to the heat exchanger 200. A combustion catalyst section 117 (e.g., a platinum-based catalyst) is arranged in the combustion exhaust gas exhaust passage 116, and reducing components such as carbon monoxide and hydrogen contained in the combustion exhaust gas are burned and removed.

The heat exchanger 200 exchanges heat between the exhaust gas generated by combustion in the combustion section 108 and the cold water being circulated, generating hot water. In other words, the heat exchanger 200 operates as a waste heat utilization section that reuses the heat discharged from the electrochemical device 100.

In place of the exhaust heat utilization section, a reaction exhaust gas utilization section may be provided that utilizes the reaction exhaust gas circulating (without being combusted) from the electrochemical module M. Also, at least a portion of the reaction exhaust gas circulating outside the housing B from the first gas exhaust section 62 may be recycled by merging with any of the locations 100, 101, 103, 106, 112, 113, and 115 in FIG. 24. The reaction exhaust gas contains residual hydrogen gas that was not used in the reaction in the electrochemical element A. In the reaction exhaust gas utilization section, the residual hydrogen gas is utilized for heat utilization by combustion or power generation by a fuel cell or the like, thereby making effective use of energy.

[Another embodiment]
[1] In the above embodiment, the connection portion 7 is formed by laser welding (welding), but the present invention is not limited thereto. For example, instead of laser welding (welding), the first plate-like body 1 and the second plate-like body 2 may be joined by a bonding material to form the connection portion 7. That is, the first plate-like body 1 and the second plate-like body 2 may be joined to form the connection portion 7 by applying a bonding material paste to the portion between the first plate-like body 1 and the second plate-like body 2 where the connection portion 7 is to be formed and baking the paste. In this case, the baking temperature is preferably less than 1000°C, more preferably 900°C or less, and even more preferably 800°C or less. By selecting a baking temperature in such a low temperature range, damage to the first plate-like body 1, the second plate-like body 2, and the electrochemical reaction portions 3a and 3b when forming the connection portion 7 can be suppressed, and a high-performance electrochemical element A can be obtained. In order to form a good connection 7, the baking temperature is preferably 600° C. or higher, more preferably 650° C. or higher, and even more preferably 700° C. or higher. As the bonding material, it is preferable to use a composite oxide composed of Co and Mn, for example.

[2] In the above embodiment, the area where the partition portion 81 of the second plate-like body 2 is formed and the first plate-like body 1 are joined by laser welding (fusion), to form the connection portion 7. However, the joining points between the second plate-like body 2 and the first plate-like body 1 are not limited to this, and the connection portion 7 may be formed by joining any point.
For example, the connection portion 7 may be formed between a region in the second plate-like body 2 where the sub-passage forming portion 80 is formed and the first plate-like body 1. In this case, the bottom surface of the sub-passage forming portion 80 in the second plate-like body 2 is separated from the lower surface of the first plate-like body 1. Therefore, as shown in Fig. 25, a conductive member 7a is disposed between these surfaces (in other words, within the sub-passage A11), and the conductive member 7a and the second plate-like body 2 and the conductive member 7a and the first plate-like body 1 are joined by welding (deposition) or by a bonding material, thereby forming the connection portion 7 including the conductive member 7a between two surfaces separated by a distance.

[3] In the above embodiment, two electrochemical reaction sections 3a, 3b are provided on the plate-shaped support 10, and a plurality of connection sections 7 are formed between the two electrochemical reaction sections 3a, 3b, but this is not limited to the above. For example, the connection section 7 may be formed at at least one location of the electrochemical reaction sections 3a, 3b. Also, for example, the connection section 7 may be formed below the electrochemical reaction sections 3a, 3b. In this case, the first plate-shaped body 1 and the second plate-shaped body 2 can be joined by welding, but there is a possibility that the electrochemical reaction sections 3a, 3b may be damaged. Therefore, when forming the connection section 7 below the electrochemical reaction sections 3a, 3b, it is preferable to form the connection section 7 by joining the first plate-shaped body 1 and the second plate-shaped body 2 with a joining material. Also, the connection section 7 may be formed between the edge of the electrochemical reaction section 3a, 3b and the edge of the plate-shaped support 10.

[4] In the above embodiment, the number of connection parts 7 is five, which is the same as the number of partition parts 81, but this is not limited to this. The number of connection parts 7 may be set appropriately taking into consideration the planar size of the electrochemical element A, etc. As in the above embodiment, when the connection parts 7 are formed by joining the upper surface of the partition part 81 in the second plate-like body 2 to the lower surface of the first plate-like body 1 in contact therewith, the connection parts 7 may be formed only on some of the multiple partition parts 81, or multiple connection parts 7 may be formed on one partition part 81, and the number of connection parts 7 does not need to be the same as the number of each partition part 81.

[5] In the above embodiment, multiple sub-flow paths A11 are provided, but this is not limited thereto, and the sub-flow path A11 may not be provided.

[6] In the above embodiment, the metal oxide layers 12, 2d are formed on the front and back surfaces of the first plate-like body 1 and the second plate-like body 2, but this is not limited thereto, and the metal oxide layers 12, 2d may not be formed.

[7] In the above embodiment, the electrochemical element A is used in a solid oxide fuel cell. However, the electrochemical element A can also be used in a solid oxide electrolysis cell, an oxygen sensor using a solid oxide, or the like.
When the electrochemical element A is operated as an electrolysis cell, a gas containing water vapor and carbon dioxide is passed through the electrode layer 31, and a voltage is applied between the electrode layer 31 and the counter electrode layer 33. Then, in the electrode layer 31, the electrons ^e- react with the water molecules _H2O and the carbon dioxide molecules _CO2 to become hydrogen molecules _H2 , carbon monoxide CO, and oxygen ions ^O2- . The oxygen ions ^O2- move through the electrolyte layer 32 to the counter electrode layer 33. Then, in the counter electrode layer 33, the oxygen ions ^O2- release electrons to become oxygen molecules _O2 . Through the above reaction, the water molecules _H2O are electrolyzed into hydrogen _H2 and oxygen _O2 , and when a gas containing carbon dioxide molecules _CO2 is passed through, they are electrolyzed into carbon monoxide CO and oxygen _O2 .
FIG. 26 shows an example of the energy system Z and the electrochemical device 100 in the case where the electrochemical reaction units 3a and 3b of the electrochemical element A are operated as electrolysis cells that generate gas by electrolysis. In this system, the supplied water and carbon dioxide are electrolyzed in the electrochemical reaction units 3a and 3b to generate hydrogen, carbon monoxide, and the like. Furthermore, hydrocarbons and the like are synthesized in the fuel converter 25. The heat exchanger 24 in FIG. 26 is operated as an exhaust heat utilization unit that heats and vaporizes water by heat exchange that reuses the reaction heat generated by the reaction occurring in the fuel converter 25, and the heat exchanger 23 in the same figure is operated as an exhaust heat utilization unit that preheats water vapor and carbon dioxide by heat exchange that reuses the exhaust heat generated by the electrochemical element A, thereby improving energy efficiency.
Therefore, according to the above configuration, it is possible to realize an electrochemical device 100 and an energy system that can improve the efficiency of converting electrical energy into chemical energy such as fuel.

[8] In the above embodiment, multiple electrochemical elements A are combined to form an electrochemical module M, but this is not limited to the above and each element can be used alone.

[9] In the above embodiment, a composite material such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO ₂ , or Cu-CeO ₂ is used as the material for the electrode layer 31, a composite oxide such as LSCF or LSM is used as the material for the counter electrode layer 33, hydrogen gas is passed through the electrode layer 31 to form a fuel electrode (anode), and air is passed through the counter electrode layer 33 to form an air electrode (cathode), for use as a solid oxide fuel cell, but the present invention is not limited to this. By changing this configuration, electrochemical element A may be configured so that the electrode layer 31 can be used as an air electrode and the counter electrode layer 33 can be used as a fuel electrode. That is, for example, a composite oxide such as LSCF or LSM is used as the material of the electrode layer 31, and for example, a composite material such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO ₂ or Cu-CeO ₂ is used as the material of the counter electrode layer 33. In the electrochemical element A configured in this manner, air is circulated through the electrode layer 31 to serve as an air electrode, and hydrogen gas is circulated through the counter electrode layer 33 to serve as a fuel electrode, so that the electrochemical element A can be used as a solid oxide fuel cell.

[10] In the above embodiment, the electrode layer 31 is disposed between the first plate-like body 1 and the electrolyte layer 32, and the counter electrode layer 33 is disposed on the side opposite the first plate-like body 1 as viewed from the electrolyte layer 32. However, the present invention is not limited to this, and the electrode layer 31 and the counter electrode layer 33 may be disposed in reverse. In other words, it is also possible to dispose the counter electrode layer 33 between the first plate-like body 1 and the electrolyte layer 32, and dispose the electrode layer 31 on the side opposite the first plate-like body 1 as viewed from the electrolyte layer 32. In this case, it is also necessary to change the flow of gas to the electrochemical element A.
In other words, various configurations can be adopted for the order of the electrode layer 31 and the counter electrode layer 33 and whether the first gas or the second gas is one or the other of the reducing component gas and the oxidizing component gas, as long as the first gas and the second gas are arranged so as to flow in a form that allows them to react appropriately with the electrode layer 31 and the counter electrode layer 33.

[11] In the above embodiment, the electrochemical reaction sections 3a and 3b are provided on the side of the first plate-like body 1 opposite the second plate-like body 2 so as to cover the gas flow-permitting section 1A, but this is not limited thereto, and the electrochemical reaction sections 3a and 3b may be provided on the second plate-like body 2 side of the first plate-like body 1. In other words, the electrochemical reaction sections 3a and 3b may be configured to be disposed in the internal flow path A1.

[12] In the above embodiment, the first through-hole 41 and the second through-hole 51 are provided in pairs at both ends of the rectangular plate-like support 10, but this is not limited to the above. The first through-hole 41 and the second through-hole 51 may be provided at a position other than both ends, or may be provided in two or more pairs. In addition, the first through-hole 41 and the second through-hole 51 do not need to be provided in pairs. Therefore, one or more first through-holes 41 and one or more second through-holes 51 can be provided.

[13] In the above embodiment, the plate-shaped support 10 is rectangular, but this is not limited to this. The shape of the plate-shaped support 10 can be various shapes such as a square shape or a circular shape.

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

[15] In the above embodiment, the first plate-like body 1 and the second plate-like body 2 form an internal flow path A1, and the internal flow path A1 has a distribution section A12, a supply adjustment section A14, a supply buffer section A15, multiple sub-flow paths A11, a discharge buffer section A16, a discharge adjustment section A17, and a junction section A13, but this is not limited to this. For example, the internal flow path A1 may have a distribution section A12, multiple sub-flow paths A11, and a junction section A13.

[16] In the above embodiment, the entire area in the second plate-like body 2 where the multiple sub-flow paths A11 are formed is formed in a corrugated shape, but this is not limited thereto, and it may be formed in a corrugated shape only in part.

The configurations disclosed in the above embodiments (including other embodiments) can be applied in combination with configurations disclosed in other embodiments, provided no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited thereto, and can be modified as appropriate within the scope of the purpose of the present invention.

The present invention can be used as an electrochemical element, an electrochemical module, an electrochemical device, an energy system, a solid oxide fuel cell, a solid oxide electrolysis cell, and a method for manufacturing an electrochemical element.

1: First plate-like body (support)
1A: Gas flow permitting portion 2: Second plate-like body 2c: Recess 2d: Metal oxide layer (metal oxide film)
3a, 3b: electrochemical reaction section 4: supply path 5: discharge path 7: connection section 7a: conductive member 8: output section 9: distribution chamber 10: plate-shaped support 12: metal oxide layer (metal oxide film)
31: electrode layer 32: electrolyte layer 33: counter electrode layer 41: first through-portion 42: first annular seal portion 51: second through-portion 52: second annular seal portion 61: first gas supply portion 71: second gas supply portion 80: sub-flow passage forming portion 81: partition portion 100: electrochemical device 102: reformer 103: fuel supply portion 104: inverter A: electrochemical element A1: internal flow passage A11: sub-flow passage A12: distribution portion A13: junction portion A14: supply adjustment portion A14a: supply passage portion A14b: supply blocking portion A15: supply buffer portion A16: discharge buffer portion A17: discharge adjustment portion A17a: discharge passage portion A17b: discharge blocking portion A2: flow portion B: housing M: electrochemical module Z: energy system

Claims (13)

A conductive plate-shaped support having an internal flow path therein;
an electrochemical reaction section including an electrode layer and a counter electrode layer formed on the plate-like support, and an electrolyte layer sandwiched between the electrode layer and the counter electrode layer;
An electrochemical element in which a connection portion that electrically connects the internal flow paths is formed in the thickness direction of the plate-shaped support , the plate-shaped support is composed of at least two conductive members, and the two conductive members have a peripheral portion that forms a conductive path . 2. The electrochemical element according to claim 1, wherein the internal flow path extends in a first direction along the plate surface of the plate support, and has a plurality of sub-flow paths extending in the first direction and spaced apart in a second direction intersecting the first direction along the plate surface of the plate support. A plurality of the electrochemical reaction units are provided on the plate-like support,
3. The electrochemical element according to claim 1, wherein the connection portion is formed at at least one location between the plurality of electrochemical reaction portions. 4. The electrochemical device according to claim 1 , wherein the plate-like support is made of a metal material. The electrochemical element according to any one of claims 1 to 4 , wherein the connection portion includes a conductive member. 6. The electrochemical element according to claim 1 , wherein at least a part of the surface of the plate-like support is covered with a metal oxide film. 7. An electrochemical module comprising a plurality of electrochemical elements according to claim 1 arranged in an assembled and electrically connected state. An electrochemical device comprising at least an electrochemical element according to any one of claims 1 to 6 or an electrochemical module according to claim 7 , and a fuel converter that generates a reducing component to be supplied to the electrochemical element or the electrochemical module, or that converts a gas containing a reducing component generated in the electrochemical element or the electrochemical module. An electrochemical device comprising at least the electrochemical element according to any one of claims 1 to 6 or the electrochemical module according to claim 7 , and a power converter that extracts electric power from the electrochemical element or the electrochemical module, or that supplies electric power to the electrochemical element or the electrochemical module. 10. An energy system comprising at least the electrochemical device according to claim 8 or 9 , and a waste heat utilization section that reuses heat discharged from the electrochemical device. A solid oxide fuel cell comprising the electrochemical element according to any one of claims 1 to 6 , wherein a power generating reaction occurs in the electrochemical element. A solid oxide electrolysis cell comprising the electrochemical element according to any one of claims 1 to 6 , in which an electrolytic reaction occurs in the electrochemical element. A method for producing the electrochemical device according to any one of claims 1 to 6 , comprising the steps of:
a connection portion forming step of forming the connection portion,
The method for manufacturing an electrochemical element, wherein the connection forming step includes at least one of a welding step and a firing step.

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