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

Abstract

To provide an electrochemical element with a simpler structure that enables electrical connection between electrochemical elements and has higher performance.SOLUTION: An electrochemical element includes a conductive plate-like support 10 having an internal channel A1 inside, and electrochemical reaction portions 3a and 3b each including an electrode layer 31 formed on a plate-like support 10, a counter electrode layer 33, and an electrolyte layer 32 sandwiched between the electrode layer 31 and the counter electrode layer 33, and the plate-like support 10 is formed with a connection portion 7 for electrically connecting the internal channels A1 in the thickness direction of the plate-like support 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to 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. [Background technology]

[0002] Patent Document 1 proposes an electrochemical module having a structure in which multiple electrochemical elements are stacked as an electrochemical module constituting an electrochemical device such as a fuel cell (electrochemical power generation cell), an electrolysis cell, etc. The electrochemical element described in Patent Document 1 includes an electrochemical reaction section in which a conductive support having a flow path formed therein, a fuel electrode layer, an electrolyte layer, and an air electrode layer are stacked in this order on the support.

[0003] In the electrochemical module described above, when a plurality of electrochemical elements are stacked, the plurality of electrochemical elements are electrically connected to each other, with the vicinity of the outer periphery of the conductive support serving as the main conductive path.

[0004] Furthermore, as a configuration in which a plurality of electrochemical elements are stacked in an electrically connected state, the configuration described in Patent Document 2 is also known.

[0005] 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. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-195029 A [Patent Document 2] International Publication No. 2017 / 090367 Summary of the Invention [Problem to be solved by the invention]

[0007] 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. Therefore, in the electrochemical element of the conventional electrochemical module, loss occurs in the power generated in the electrochemical reaction section and in the power applied to the electrochemical reaction section, and the performance of the electrochemical element is not fully utilized.

[0008] In addition, the conductive vias described in Patent Document 2 must penetrate the separator in the stacking direction in order to electrically connect the fuel electrode layer and the air electrode layer to the connection parts. This results in a complicated structure of the fuel cell, which is difficult to fabricate and increases the manufacturing costs of the fuel cell. In addition, the complicated structure of the fuel cell makes it prone to low durability and performance degradation due to breakage, etc.

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide an electrochemical element that enables electrical connection between electrochemical elements with a simpler structure and has higher performance, an electrochemical module, an electrochemical device, an energy system, a solid oxide fuel cell, and a solid oxide electrolysis cell that include this electrochemical element, and a method for manufacturing an electrochemical element. [Means for solving the problem]

[0010] 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-like support has a connection portion formed in a thickness direction of the plate-like support for electrically connecting the internal flow paths. The plate-shaped support is composed of at least two conductive members, and the two conductive members have a peripheral portion that serves as a conductive path. It's at the point.

[0011] 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 the fabrication is easy. 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 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 reduces the conductive resistance inside the electrochemical element and realizes an electrochemical element with higher performance.

[0014] 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.

[0015] 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 the 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 flow resistance of the gas differs between the center and the outer periphery of the internal flow path, and there is a possibility that the flow speed of the gas may differ. If such a speed difference occurs, the amount of gas that reaches the electrochemical reaction section also differs, and therefore the efficiency of generating the electrochemical output also differs, and there is a risk of problems such as the occurrence of a portion that becomes locally hot or rapidly deteriorates. 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 the case where 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 flow speed of the gas is 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 gas is insufficient and the parts where gas is excessively flowing, and a uniform reaction field can be formed over a wide area of ​​the electrochemical reaction section. Therefore, when power is generated in the entire electrochemical element, the power generation efficiency can be improved and the occurrence of the above problems can be suppressed. Furthermore, when an electrolytic reaction is performed, the reaction can be made to proceed efficiently.

[0016] 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.

[0017] 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.

[0018] A further characteristic configuration of the electrochemical element according to the present invention is The plate-like support is made of a metal member.

[0019] According to the above characteristic configuration, the electrochemical element has components of the electrochemical reaction section, such as the electrode layer, electrolyte layer, and counter electrode layer, formed on a plate-like support made of a metal member having 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 thinner. Therefore, it is possible to ensure high performance and durability of the electrochemical element while reducing the material cost of the electrochemical element.

[0020] 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.

[0021] According to the above-mentioned characteristic configuration, even when the flow path diameter of the internal flow path is large in the thickness direction of the plate-shaped support (in other words, even when the distance between opposing surfaces of the inner surface of the plate-shaped support that constitutes the internal flow path is large in the thickness direction of the plate-shaped support), a connection portion that electrically connects the internal flow paths can be formed using a conductive material.

[0022] 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.

[0023] According to the above characteristic configuration, it is possible to prevent components such as Cr from diffusing from the plate-like support to the electrode layer of the electrochemical reaction section, etc., thereby preventing the performance of the electrode layer, etc. from deteriorating and improving the performance and durability of the electrochemical element.

[0024] 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.

[0025] According to the above-mentioned characteristic configuration, by electrically connecting multiple electrochemical elements and arranging multiple electrochemical elements in a group, it is possible to realize a compact, high-performance electrochemical module that is strong and reliable while suppressing material costs and processing costs. Furthermore, when the electrochemical module is operated as a fuel cell, for example, it is possible to obtain a large power generation output.

[0026] 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.

[0027] 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 using 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 easier 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, electrons e - reacts with water molecules H2O and carbon dioxide molecules CO2 to produce hydrogen molecules H2, carbon monoxide CO, and oxygen ions O 2- The generated oxygen ions O 2- The oxygen ions O move through the electrolyte layer to the counter electrode layer. 2- releases electrons and becomes oxygen molecules O2. Through the above reaction, when gas containing water vapor flows, water molecules H2O are decomposed into hydrogen H2 and oxygen O2, and when gas containing carbon dioxide molecules CO2 flows, they are electrolyzed into carbon monoxide CO and oxygen O2. Therefore, when 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 this system / device and use them as fuel or chemical raw materials.

[0028] 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.

[0029] According to the above characteristic configuration, the power converter can extract the power generated by the electrochemical element or electrochemical module, or can distribute 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. 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.

[0030] 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.

[0031] According to the above characteristic configuration, an energy system with excellent durability, reliability, and performance as well as excellent energy efficiency can be realized. It is also possible to realize a hybrid system with excellent energy efficiency by combining it with a power generation system that generates power by utilizing the combustion heat of unused fuel gas discharged from the electrochemical device.

[0032] 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.

[0033] According to the above-mentioned characteristic configuration, a power generation reaction can be carried out as a solid oxide fuel cell equipped with an electrochemical element that is excellent in durability, reliability, and performance, so that a highly durable and high-performance solid oxide fuel cell can be obtained.

[0034] 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.

[0035] According to the above characteristic configuration, gas can be generated by an electrolytic reaction as a solid oxide electrolysis cell equipped with an electrochemical element or electrochemical module with excellent durability, reliability, and performance, so that a highly durable and high-performance solid oxide electrolysis cell can be obtained.

[0036] 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.

[0037] According to the above characteristic configuration, the connection portion can be formed suitably. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an electrochemical element. [Diagram 2] FIG. 2 is a bottom view showing an electrochemical element. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 2 is a cross-sectional view of FIG. 1 in accordance with the VV diagram. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] IX-IX cross-sectional view in FIG. [Figure 10] 2 is a cross-sectional view taken along the line XX in FIG. [Figure 11] 1. FIG. 1 is a cross-sectional view taken along the line XI-XI in FIG. [Figure 12] 1. This is a cross-sectional view taken along the line XII-XII in FIG. [Figure 13] 1. FIG. 1 is a cross-sectional view taken along the line XIII-XIII in FIG. [Figure 14] 1. This is a cross-sectional view taken along the line XIV-XIV in FIG. [Figure 15] 1. This is a cross-sectional view taken along the line XV-XV in FIG. [Figure 16] 1. FIG. 1 is a cross-sectional view taken along the line XVI-XVI in FIG. [Figure 17] 1. This is a cross-sectional view taken along the line XVII-XVII in FIG. [Figure 18] 1. FIG. 1 is a cross-sectional view taken along the line XVIII-XVIII in FIG. [Figure 19] 1. FIG. 2 is a cross-sectional view taken along the line XIX-XIX in FIG. [Figure 20] FIG. 13 is a diagram showing a state in which a connection portion is formed by laser welding. [Figure 21] FIG. 2 is an enlarged view of a main part of the electrochemical element. [Figure 22] 11A and 11B are diagrams for explaining a supply structure and a discharge structure. [Diagram 23] FIG. 2 is a schematic diagram showing an electrochemical module. [Figure 24] FIG. 1 is a schematic diagram showing an energy system. [Diagram 25] FIG. 4 is a cross-sectional view showing an electrochemical element according to another embodiment. [Figure 26] FIG. 11 is a schematic diagram showing an energy system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Hereinafter, 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 according to embodiments of the present invention will be described with reference to the drawings.

[0040] When expressing the positional relationship of layers, for example, the counter electrode layer side as viewed from the electrolyte layer may be referred to as "upper" or "upper side", and the electrode layer side as "lower" or "lower side". The lamination 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 generally perpendicular to each other.

[0041] (Electrochemical element) First, the electrochemical element A will be described. As shown in Fig. 1 to Fig. 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 with a gap therebetween 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 fuel gas containing hydrogen and air.

[0042] (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 rectangular in top view and is 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 in 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-penetrating 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-penetrating direction of the plate-like support 10.

[0043] 4, 9 to 11, 17, 18, etc., a plate-shaped annular spacer 92 having 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 10. The 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 10. The annular spacer 92 has a flow path for passing gas 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.

[0044] (First plate-shaped body) The first plate-like body 1 supports the electrode layer 31, electrolyte layer 32, and counter electrode layer 33 constituting the electrochemical reaction sections 3a and 3b, and plays a role in maintaining the strength of the electrochemical element A. The material of the first plate-like body 1 is a material having excellent electronic conductivity, heat resistance, oxidation resistance, and corrosion resistance. For example, ferritic stainless steel, austenitic stainless steel, nickel-based alloys, etc. are used, but are not limited thereto. In particular, alloys containing chromium are preferably used. In this embodiment, the first plate-like body 1 uses an Fe-Cr-based 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.

[0045] The first plate-like body 1 is generally plate-like. It has a gas flow-permitting portion 1A having a large number of through holes 11 penetrating 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 region where the electrochemical reaction portions 3a and 3b are formed, and the gas flow-permitting portion 1A is not formed in the region where the electrochemical reaction portions 3a and 3b are not formed (the region 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.

[0046] 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. The gas flow-permitting portion 1A is preferably provided in an area of ​​the first plate-like body 1 that is smaller than the area where the electrode layer 31 is provided. Note that, in order to impart gas permeability to the first plate-like body 1, it is also possible to use a porous metal such as a sintered metal or a foamed metal.

[0047] As shown in FIG. 21, the first plate-like 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-like 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-like 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-like body 1 and the electrode layer 31. For example, when ferritic stainless steel containing chromium is used as the first plate-like 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 and the like of the first plate-like 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.

[0048] 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 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 may be formed by plating and oxidation treatment. Furthermore, the metal oxide layer 12 may contain a highly conductive spinel phase, etc.

[0049] When a ferritic stainless steel material 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 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 a temperature cycle of low and high temperatures is repeated. This is preferable because it allows the realization of an electrochemical element A with excellent long-term durability.

[0050] (Second plate-shaped 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 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 techniques 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.

[0051] 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.

[0052] Since the second plate-like body 2 is closely related to the configuration of the internal flow path A1, 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.

[0053] (Configuration of the second plate-like body and the internal flow passage) In this embodiment, the internal flow path A1 has, in the flow direction of the first gas (i.e., from the +X direction to the -x direction), 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. 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.

[0054] 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 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 as to be recessed downward (-Z direction) in the stacking direction from the peripheral edge portion 1a. As shown in FIG. 1 and FIG. 22, the first through portion 41 is located approximately in the center of the distribution section A12 in the flow direction and the cross direction (Y direction). That is, 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.

[0055] 1, etc., the length of the distribution section A12 in the Y direction corresponds to the length in the Y direction of a region of a plurality of sub-flow paths A11 (described later) that are arranged in parallel to each other at intervals in the Y direction.

[0056] The plurality of sub-flow paths A11 through which the first gas flows extend in the first direction (X direction) in the direction along the plate-like surface of the plate-like support 10, and are separated in the second direction (Y direction) intersecting the first direction (X direction) in the direction along the plate-like surface of the plate-like support 10 and extend in the first direction (X direction). Specifically, as shown in FIGS. 1 and 22 etc., the plurality of sub-flow paths A11 extend from the vicinity of the supply adjustment part A14 described later to the vicinity of the discharge adjustment part A17 along the flow direction (X direction). And the plurality of sub-flow paths A11 are arranged in parallel at intervals in the Y direction. The second plate-like body 2 has, as shown in FIGS. 1, 2, 7 to 10 etc., a plurality of sub-flow path forming parts 80 forming the plurality of sub-flow paths A11 respectively, and a plurality of partition parts 81 provided between adjacent sub-flow path forming parts 80 and partitioning the adjacent sub-flow paths A11 respectively. As shown in FIGS. 14 and 21 etc., the sub-flow path forming part 80 is formed in a concave shape having a bottom surface, and the upper surface of the partition part 81 is located above the bottom surface of the sub-flow path forming part 80 in the stacking direction. And the upper surface of the partition part 81 is in contact with the lower surface of the first plate-like body 1. Thereby, each sub-flow path A11 is separated, and the first gas flows through each sub-flow path A11 along the flow direction respectively.

[0057] In the present embodiment, as shown in FIG. 22, in the Y direction (the intersecting direction intersecting the flow direction), the length L3 of the partition part 81 is smaller than the length L4 of the sub-flow path forming part 80 (L3 < L4). When L3 < L4, as shown in FIG. 21 etc., the contact area between the upper surface of the partition part 81 and the lower surface of the first plate-like body 1 can be made smaller. That is, the space of the sub-flow path A11 facing the first plate-like body 1 in which the gas flow allowance part 1A is formed can be enlarged, and the amount of the first gas flowing from the sub-flow path A11 toward the electrochemical reaction parts 3a, 3b can be increased.

[0058] As shown in FIGS. 1 and 6 to 10 etc., the second plate-like body 2 has a supply adjustment part A14 between the distribution part A12 and the plurality of sub-flow paths A11 in the direction along the flow direction (X direction). The supply adjustment part A14 temporarily stores the first gas in the distribution part A12 and restricts the supply of the first gas from the distribution part A12 to the plurality of sub-flow paths A11.

[0059] 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 and other figures, 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. Thus, 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.

[0060] In this embodiment, each supply blocking portion A14b is formed in a generally rectangular shape, for example as shown in Fig. 1 and 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.

[0061] In addition, in the flow direction (X direction), one of the partitions 81 is arranged to correspond to the supply passing portion A14a. In addition, in the flow direction, at least one of the sub-flow paths A11 is arranged to correspond to the supply blocking portion A14b. Specifically, in this embodiment, two of the multiple supply blocking portions A14b are provided at positions corresponding to the end portion in the +Y direction and the end portion in the -Y direction of the distributor A12, respectively.

[0062] Here, the first gas is guided from the distribution section A12 through the supply passage 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 A14a in the flow direction, the first gas pushed out from the distribution section A12 to the supply passage A14a travels along the flow direction and collides with the partition 81 protruding upward in the stacking direction. Due to the collision with the partition 81, the first gas travels in a cross direction that crosses the flow direction. In other words, the first gas that has flowed from the distribution section A12 through the supply passage A14a is not immediately introduced into the multiple sub-flow paths A11, but collides with the partition 81 just before the sub-flow path A11 and travels in the cross direction. Furthermore, the first gas that has traveled in the cross direction is not returned to the distribution section A12 by 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. Thereafter, the first gas is introduced along the extrusion from the distribution section A12 into the plurality of sub-flow paths A11 formed by the plurality of sub-flow path forming sections 80. The region where the first gas is temporarily stored between the supply adjustment section A14 and the plurality of sub-flow paths A11 is the supply buffer section A15.

[0063] In addition, in the flow direction, the supply blocking portion A14b is provided corresponding to the first through-portion 41. This makes it possible to prevent the first gas introduced into the distribution portion A12 from the first through-portion 41 from immediately moving toward the multiple sub-flow paths A11. Therefore, it is possible to temporarily store the first gas in the distribution portion A12.

[0064] As shown in FIG. 22, in the Y direction, the length L2 of the supply blocking portion A14b is greater than the length L1 of the supply passing portion A14a (L2 > L1). Also, the length L1 of the supply passing portion A14a is preferably smaller than the length L3 of the partition portion 81 (L1 < L3). Thereby, the first gas pushed out from the distribution portion A12 through the supply passing portion A14a can be made to collide with the end portion on the +X direction side of the partition portion 81, and can be temporarily stored in the supply buffer portion A15 described later. The relationship between L1 and L2 is determined by, for example, 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 plurality of sub-flow paths A11 per unit time, the number of the supply blocking portions A14b, the length L3 in the Y direction of the partition portion 81, the length L4 in the Y direction of the sub-flow path A11, and the like.

[0065] In addition, the number, arrangement, and shape of the supply blocking portion A14b and the supply passing portion A14a may be in any form as long as these functions are exhibited.

[0066] In this manner, the supply blocking portion A14b of the supply adjustment portion A14 having the above-mentioned configuration is provided between the distribution portion A12 and the plurality of sub-flow paths A11, and serves as a barrier to the flow of the first gas from the distribution portion A12 to the plurality of sub-flow paths A11. Therefore, the pressure loss of the first gas increases when the first gas flows from the distribution portion A12 to the plurality of sub-flow paths A11, and the first gas introduced into the distribution portion A12 spreads so as to fill the distribution portion A12 and is temporarily stored. Therefore, the entire inside of the distribution portion A12 is at a substantially uniform pressure (equal pressure). In other words, the differential pressure between the distribution portion A12 and each of the plurality of sub-flow paths A11 is substantially the same. In addition, the first gas is supplied from the distribution portion A12 to the plurality of sub-flow paths A11 via the supply passage portion A14a, so that the first gas is supplied to each of the sub-flow paths A11 in a substantially equal pressure state. As a result, the flow distribution (flow velocity, flow rate, pressure, etc.) of the first gas along the flow direction is substantially uniform between each of the sub-flow paths A11. Furthermore, the first gas is divided into a plurality of sub-flow paths A11 from the distribution section A12 and flows therethrough. Due to the rectification effect of the first gas being divided into a plurality of flow paths in this manner, 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 a plurality of flow paths is not formed. This reduces the difference between the portions of the electrochemical reaction sections 3a, 3b where the first gas is insufficient and the portions where the first gas flows in excess, thereby improving the utilization rate of the first gas in the entire electrochemical element A and improving the reaction efficiency of the electrochemical reaction.

[0067] Next, the confluence A13 and the discharge adjustment section A17 will be described. The confluence A13 and the discharge adjustment section A17 have the same configuration as the distribution section A12 and the supply adjustment section A14, respectively. That is, the confluence 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 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 through-portion 51 is located approximately in the center of the confluence 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 through-portion 51 are formed at this position.

[0068] 1, etc., the junction A13 is elongated in the Y direction in top view. The length of the junction A13 in the Y direction 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.

[0069] 1, 13, and 15 to 18, the second plate-like body 2 has a discharge adjustment section A17 between the sub-flow paths A11 and the junction A13 in the flow direction (X direction). The discharge adjustment section A17 limits the discharge of the first gas from the sub-flow paths A11 to the junction A13.

[0070] The discharge adjustment section A17 has a plurality of discharge passing sections A17a and a plurality of discharge blocking sections A17b. The discharge passing sections A17a pass the first gas 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 and other figures, the upper surface of the discharge blocking section A17b is located above the upper surface of the discharge passing sections A17a in the stacking direction and abuts against the lower surface of the first plate-like body 1. Thus, the first gas in the plurality of sub-flow paths A11 is blocked from flowing in the flow direction by the discharge blocking sections A17b, while flowing in the flow direction through the discharge passing sections A17a to flow to the junction A13.

[0071] 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. The 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.

[0072] 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 partitions 81 is arranged to correspond to the discharge passing portion A17a.

[0073] 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. The collision with the discharge blocking portion A17b causes the first gas to travel in a cross direction intersecting with 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 before the junction A13 and travels in the cross direction. After that, the first gas 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 where 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.

[0074] In addition, in the flow direction, the discharge prevention portion A17b is provided corresponding to the second through-portion 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 can be prevented from being discharged from the second through-portion 51. Therefore, the first gas can be temporarily stored in the multiple sub-flow paths A11.

[0075] As shown in FIG. 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 sub-flow passage forming portion 80 (L12>L3). This allows the first gas flowing from the multiple sub-flow passages A11 toward the junction A13 to collide with the discharge blocking portion A17b and temporarily accumulate in the discharge buffer portion A16 described below. The relationship between L11 and L12 is determined by, for example, the amount of the first gas supplied to the multiple sub-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 sub-flow passage A11 in the Y direction, and the like.

[0076] The number, arrangement, and shape of the discharge blocking portions A17b and the discharge passing portions A17a may be any as long as these functions are fulfilled.

[0077] In this manner, the discharge blocking portion A17b of the discharge adjustment portion A17 having the above-mentioned configuration is provided between the plurality of 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 the first gas flows from the plurality of sub-flow paths A11 to the junction A13. Therefore, the first gas introduced into the plurality of sub-flow paths A11 is not easily introduced into the junction A13 immediately from the plurality of sub-flow paths A11, and spreads so as to fill the plurality of sub-flow paths A11. This allows the flow distribution (flow velocity, flow rate, pressure, etc.) of the first gas along the flow direction to be roughly uniform between the respective sub-flow paths A11. In addition, since the first gas spreads so as to fill the plurality of sub-flow paths A11, the electrochemical reaction is sufficiently carried out in the plurality of sub-flow paths A11. As a result, the reaction efficiency of the electrochemical reaction can be improved.

[0078] In the present embodiment, a metal oxide layer 2d (metal oxide film) is formed on the second plate-like body 2 as shown in Fig. 21. 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. The metal oxide layer 2d may 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, the metal oxide layer 2d may contain a highly conductive spinel phase or the like.

[0079] As shown in Figures 1 and 19, in this embodiment, between the two electrochemical reaction sections 3a, 3b, the upper surface of each partition portion 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 portions 7 are formed that electrically connect the internal flow paths A1 in the thickness direction of the plate-like support body 10.

[0080] The connection parts 7 are formed by performing a connection part forming step of forming the connection parts 7 when manufacturing the electrochemical element A, and the connection part forming step includes at least one of a welding (adhesion) step and a baking step. In this embodiment, the connection parts 7 are 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 melted metal N is used to join the first plate-like body 1 to a part of each partition part 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.

[0081] By forming the connection part 7 in this manner, 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 the case where 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.

[0082] Furthermore, the connection portion 7 has a simpler structure than a case where a conductive via is formed. In addition, processes such as forming a through hole required for forming a conductive via and filling the through hole with a conductive material are not required. Therefore, a decrease in durability and deterioration of performance are unlikely to occur, and the manufacturing cost of the electrochemical element A can be reduced.

[0083] (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 omitted from Figures 7 to 10 and 14 to 18.

[0084] (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 provided as 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 reduce the amount of expensive electrode layer material used to reduce costs while ensuring sufficient electrode performance. 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.

[0085] Moreover, the electrode layer 31 has a plurality of pores inside and on the surface thereof 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. The 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.

[0086] 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-CeO2, or Cu-CeO2. In these examples, GDC, YSZ, and CeO2 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 firing 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 prevent damage to the first plate-like body 1 and suppress interdiffusion of elements between the first plate-like body 1 and the electrode layer 31, thereby realizing an electrochemical device A with excellent durability. Furthermore, the use of a low-temperature firing method is even more preferable because it makes it easier to handle the raw materials.

[0087] The electrode layer 31 may be configured such that the content ratio, density, and strength of the aggregate of the cermet material continuously increase 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 make the content ratio, density, strength, etc. of the aggregate of the cermet material higher in the portion of the electrode layer 31 adjacent to the electrolyte layer 32 (upper portion) than in the portion of the electrode layer 31 adjacent to the first plate-like body 1 (lower portion).

[0088] (Middle class) The intermediate layer 34 can be formed as 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.

[0089] 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, interdiffusion of elements between the first plate-like body 1 and the electrode layer 31 can be suppressed without damaging the first plate-like body 1, and an electrochemical device A with excellent durability can be realized. Furthermore, using a low-temperature firing method is more preferable because it makes it easier to handle the raw materials.

[0090] The intermediate layer 34 preferably has oxygen ion (oxide ion) conductivity, and more preferably has mixed conductivity of oxygen ions (oxide ions) and electrons. The intermediate layer 34 having these properties is suitable for application to the electrochemical device A.

[0091] (electrolyte layer) As shown in Figs. 7 to 10, 14 to 18, and 21, the electrolyte layer 32 is formed in a thin layer state on the intermediate layer 34 in a state where it covers the electrode layer 31 and the intermediate layer 34. It may also be formed in a thin film state with 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, it is possible to make the electrochemical element A excellent in robustness as a whole.

[0092] 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 the first plate-like body 1 in which the electrolyte layer 32 is formed.

[0093] Moreover, gas leakage from the electrode layer 31 and the 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 from the back side of the first plate-like body 1 through the through-holes 11 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 the electrode layer 31 and the intermediate layer 34 and a gasket or the like is provided around the periphery may also be used.

[0094] As the material of the electrolyte layer 32, an electrolyte material that conducts oxygen ions, such as YSZ (yttria-stabilized zirconia), SSZ (scandium-stabilized zirconia), GDC (gadolinium-doped ceria), YDC (yttrium-doped ceria), SDC (samarium-doped ceria), LSGM (strontium-magnesium-doped lanthanum gallate), or an electrolyte material that conducts 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 or various hydrogen ion conductive materials. For example, when electrochemical element A is used in a SOFC, a material that can exhibit high electrolyte performance even at high temperatures of about 650°C or more, such as YSZ, is used as the material for electrolyte layer 32, a hydrocarbon-based raw fuel such as city gas or LPG is used as the raw fuel for the system, and the raw fuel is converted into SOFC anode gas by steam reforming or the like. In this way, 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.

[0095] 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 a low temperature range, the electrolyte layer 32 that is dense and has high airtightness and gas barrier properties can be obtained without using firing at a high temperature range exceeding 1100°C. Therefore, damage to the first plate-like body 1 can be suppressed, and the interdiffusion of elements between the first plate-like body 1 and the electrode layer 31 can be suppressed, and an electrochemical element A with excellent performance and durability can be realized. In particular, the low-temperature firing method and the spray coating method are preferable because they can realize a low-cost element. Furthermore, the spray coating method is even more preferable because the electrolyte layer 32 that is dense and has high airtightness and gas barrier properties can be easily obtained at a low temperature range.

[0096] The electrolyte layer 32 is densely configured to prevent 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 configured in a multi-layered form, it is preferable that at least a part of the electrolyte layer 32 includes a layer (a dense electrolyte layer) having a density of 98% or more, and more preferably includes a layer (a dense electrolyte layer) having a density of 99% or more. When 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 configured in a multi-layered form.

[0097] (Reaction prevention layer) 21, the reaction prevention layer 35 can be formed as a thin layer on the electrolyte layer 32. When the reaction prevention layer 35 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 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.

[0098] 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. The material of the reaction prevention layer 35 is preferably a material containing at least one element selected from the group consisting of Sm, Gd, and Y. The material preferably contains at least one element selected from the group consisting of Sm, Gd, and Y, and the total content of these elements is preferably 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.

[0099] The reaction prevention layer 35 is preferably formed using an appropriate method that allows formation 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, the use of a low-temperature firing method or a spray coating method is preferable, since it allows a low-cost element to be realized. Furthermore, the use of a low-temperature firing method is even more preferable, since it makes it easier to handle the raw materials.

[0100] (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 cut costs while ensuring sufficient electrode performance.

[0101] The material of the counter electrode layer 33 may be, for example, a composite oxide such as LSCF or LSM, a ceria-based oxide, or a mixture thereof. In particular, the counter electrode layer 33 preferably 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 formed using the above materials functions as a cathode.

[0102] The counter electrode layer 33 is preferably formed using a suitable method that allows the layer to be formed 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 counter electrode layer 33 can be formed using a suitable method similar to that used for forming the electrode layer 31. In particular, the use of a low-temperature firing method or a spray coating method is preferable, since it allows the element to be realized at low cost. Furthermore, the use of a low-temperature firing method is even more preferable, since it allows the raw materials to be easily handled.

[0103] (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.

[0104] For example, a fuel gas containing hydrogen as a first gas is passed through the through holes 11 from the rear surface of the first plate-like body 1 to the electrode layer 31, and air as a second gas is passed 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 is converted into electrons e - reacts with oxygen ions O 2- The oxygen ion O 2- The hydrogen H2 contained in the flowing fuel gas is converted into oxygen ions O2- reacts with water H2O and electrons e - is generated.

[0105] 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 is converted into electrons e - releases hydrogen ions H + The hydrogen ion H + moves through the electrolyte layer 32 to the counter electrode layer 33. In the counter electrode layer 33, oxygen O2 and hydrogen ions H + , electronic e - reacts to produce water, H2O.

[0106] By the above reaction, an electromotive force is generated as an electrochemical output between the electrode layer 31 and the counter electrode layer 33. In this case, the electrode layer 31 functions as a fuel electrode (anode) of the fuel cell, and the counter electrode layer 33 functions as an air electrode (cathode).

[0107] A solid oxide fuel cell that can operate at a temperature range of 650°C or higher during rated operation is more preferable because it can improve the power generation efficiency of a fuel cell system that uses a hydrocarbon gas such as city gas as a raw fuel, since it can be constructed such that the heat required for converting the raw fuel into hydrogen can be supplied by the exhaust heat of the fuel cell. A solid oxide fuel cell that operates at a temperature range of 900°C or lower during rated operation is more preferable because it can enhance the effect of suppressing Cr volatilization from the metal-supported electrochemical element A, and a solid oxide fuel cell that operates at a temperature range of 850°C or lower during rated operation is even more preferable because it can further enhance the effect of suppressing Cr volatilization.

[0108] (Electrochemical Module) Next, the electrochemical module M will be described with reference to FIGS.

[0109] As shown in FIG. 23, an electrochemical module M includes a housing B made of an insulating material in which a plurality of electrochemical elements A are housed.

[0110] The multiple electrochemical elements A are stacked and arranged in the housing B in a form in which the plate-like support 10 constituting one electrochemical element A faces the plate-like support 10 constituting another electrochemical element A, and in a state in which the lower surface of a region forming the sub-flow path forming portion 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 portion 3a, 3b constituting the other electrochemical element A. In addition, between the lower surface 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 portion A2 through which the second gas flows is formed along these two surfaces.

[0111] 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. Also, 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.

[0112] 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.

[0113] The electrochemical elements A are housed in the housing B in a state of being sandwiched between a pair of current collectors 91, 82, and an output unit 8, which will be described later, is extended from the current collectors 91, 82 and is connected to an electrode for freely supplying power to a power supply destination outside the housing B. The current collectors 91, 82 are provided to accommodate the electrochemical elements A in an airtight manner in the housing B and to function as a buffer material for each electrochemical element A.

[0114] Moreover, 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 the outside of 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 the 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, 3b, and includes a distribution chamber 9 within the housing B that distributes the second gas supplied from the second gas supply unit 71 to the flow section A2.

[0115] As a result, the electrochemical module M supplies fuel gas (sometimes referred to as first gas) from the first gas supply unit 61 and air (sometimes referred to as 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.

[0116] 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 the electrochemical elements A. In this embodiment, the flow direction of the fuel gas passing through the internal flow path A1 along the plane of the plate-like support 10 is from the +X direction to the -X direction. Similarly, the flow direction of the air passing through the flow portion A2 along the plane of the plate-like support 10 is from the +X direction to the -X direction.

[0117] 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. The fuel gas supplied from the first gas supply section 61 reaches the distribution section A12 (see Figures 1, 4, 5, etc.), and flows and spreads 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.).

[0118] The fuel gas flows through the first gas supply unit 61, the first annular seal unit 42, the first through-hole 41, etc., and is supplied to the distribution unit A12 of each electrochemical element A. The fuel gas supplied to the distribution unit A12 is temporarily stored in the distribution unit A12 by the supply adjustment unit A14. The fuel gas is then introduced from the distribution unit A12 into the plurality of sub-flow paths A11. The fuel gas that has entered each of the sub-flow paths A11 flows through each of the sub-flow paths A11, and enters the electrode layer 31 and the electrolyte layer 32 through the gas flow permitting unit 1A. The fuel gas also travels further through the sub-flow paths A11 together with the fuel gas that has undergone the electrochemical reaction. The fuel gas that has reached the end of the plurality of sub-flow paths A11 in the flow direction advances to the junction A13 in a state in which the flow to the junction A13 is partially restricted by the discharge adjustment unit A17. The fuel gas that has reached the junction A13 flows through the junction A13, the second through-hole 51, the second annular seal portion 52, etc. Then, the fuel gas that has undergone the electrochemical reaction from the other electrochemical elements A is discharged to the outside through the first gas discharge portion 62.

[0119] On the other hand, the air supplied from the second gas supply unit 71 enters the flow section A2 through the distribution chamber 9, and can enter the counter electrode layer 33 and the electrolyte layer 32. The air further travels through the flow section A2 along the electrochemical reaction sections 3a and 3b together with the air that has undergone the electrochemical reaction, and is discharged to the outside from the second gas discharge section 72.

[0120] 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 current 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 a 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 current 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.

[0121] (Electrochemical Devices and Energy Systems) Next, an electrochemical device 100 and an energy system Z constructed using the electrochemical module M will be described.

[0122] 24 shows an overview of an electrochemical device 100 and an energy system Z. As shown in the figure, the energy system Z has an electrochemical device 100 and a heat exchanger 200 as an exhaust heat utilization section that reuses heat circulated from the electrochemical device 100.

[0123] 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.

[0124] More specifically, the electrochemical device 100 includes a desulfurizer 101, a reforming water tank 105, a vaporizer 106, a reformer 102, a blower 107, a combustion unit 108, an inverter 104, a control unit 110, and an electrochemical module M.

[0125] The desulfurizer 101 removes (desulfurizes) sulfur compounds contained in a hydrocarbon-based 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, and generates a reformed gas containing hydrogen.

[0126] The electrochemical module M generates power by electrochemical reaction using the reformed gas circulated from the reformer 102 and 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 combustible components in the reaction exhaust gas.

[0127] The inverter 104 adjusts the output power of the electrochemical module M to the same voltage and frequency as the power received from a commercial grid (not shown). The control unit 110 controls the operation of the electrochemical device 100 and the energy system Z.

[0128] The reformer 102 performs a reforming process of the raw fuel using the combustion heat generated by the combustion of the reaction exhaust gas in the combustion section 108 .

[0129] The raw fuel is circulated to the desulfurizer 101 through a raw fuel supply passage 112 by the operation of a boost pump 111. The reforming water in the reforming water tank 105 is circulated to the vaporizer 106 through a reforming water supply passage 114 by the operation of a 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 have been merged outside the casing B are circulated to the vaporizer 106.

[0130] 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 a 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.

[0131] The reaction exhaust gas is combusted in the combustion section 108 to become a combustion exhaust gas, which is sent from the combustion exhaust gas discharge 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 discharge passage 116, and reducing components such as carbon monoxide and hydrogen contained in the combustion exhaust gas are burned and removed.

[0132] The heat exchanger 200 exchanges heat between the combustion exhaust gas generated by the combustion in the combustion section 108 and the cold water passing through it, thereby generating hot water. That is, the heat exchanger 200 operates as a waste heat utilization section that reuses the heat discharged from the electrochemical device 100.

[0133] Instead 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 part of the reaction exhaust gas circulating from the first gas discharge section 62 to the outside of the housing B 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 for power generation by a fuel cell or the like, thereby making effective use of energy.

[0134] [Another embodiment] [1] In the above embodiment, the connection portion 7 is formed by laser welding (welding), but this is not limited to this. For example, instead of laser welding (welding), the connection portion 7 may be formed by joining the first plate-like body 1 and the second plate-like body 2 with a bonding material. In other words, 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 location 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 1000°C. less than It is preferable that the baking temperature is 600°C or higher, more preferably 900°C or lower, and even more preferably 800°C or lower. 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 parts 3a and 3b when forming the connection parts 7 can be suppressed, and a high-performance electrochemical element A can be obtained. In order to form good connection parts 7, the baking temperature is preferably 600°C or higher, more preferably 650°C or higher, and even more preferably 700°C or higher. It is preferable to use a composite oxide composed of, for example, Co and Mn as the bonding material.

[0135] [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 the two surfaces separated by a distance.

[0136] [3] In the above embodiment, two electrochemical reaction parts 3a, 3b are provided on the plate-shaped support 10, and a plurality of connection parts 7 are formed between the two electrochemical reaction parts 3a, 3b, but the present invention is not limited to this. For example, the connection part 7 may be formed at at least one place of the electrochemical reaction parts 3a, 3b. Also, for example, the connection part 7 may be formed below the electrochemical reaction parts 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 parts 3a, 3b may be damaged. Therefore, when the connection part 7 is formed below the electrochemical reaction parts 3a, 3b, it is preferable to form the connection part 7 by joining the first plate-shaped body 1 and the second plate-shaped body 2 with a bonding material. Also, the connection part 7 may be formed between the edge part of the electrochemical reaction part 3a, 3b and the edge part of the plate-shaped support 10.

[0137] [4] In the above embodiment, the number of the connection parts 7 is five, which is the same as the number of the partition parts 81, but this is not limited to the above. The number of the connection parts 7 may be appropriately set in consideration of 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 the connection parts 7 does not need to be the same as the number of the partition parts 81.

[0138] [5] In the above embodiment, a plurality of sub-flow paths A11 are provided, but the present invention is not limited to this. A configuration in which no sub-flow path A11 is provided may also be used.

[0139] [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 to this, and the metal oxide layers 12, 2d may not be formed.

[0140] [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 device A is operated as an electrolytic 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, electrons e - reacts with water molecules H2O and carbon dioxide molecules CO2, producing hydrogen molecules H2, carbon monoxide CO, and oxygen ions O 2- Oxygen ion O 2- The oxygen ions O 2 are transported through the electrolyte layer 32 to the counter electrode layer 33. 2- releases electrons and becomes oxygen molecules O2. Through the above reaction, water molecules H2O are electrolyzed into hydrogen H2 and oxygen O2, and when gas containing carbon dioxide molecules CO2 is circulated, it is 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 that occurs 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.

[0141] [8] In the above embodiment, a plurality of electrochemical elements A are combined to form the electrochemical module M, but the present invention is not limited to this and each electrochemical element may be used alone.

[0142] [9] In the above embodiment, the electrode layer 31 is made of a composite material such as NiO-GDC, Ni-GDC, NiO-YSZ, Ni-YSZ, CuO-CeO2, or Cu-CeO2, the counter electrode layer 33 is made of a composite oxide such as LSCF or LSM, hydrogen gas is passed through the electrode layer 31 to make it a fuel electrode (anode), and air is passed through the counter electrode layer 33 to make it an air electrode (cathode), and the solid oxide fuel cell is used, but the present invention is not limited to this. The electrochemical element A may be configured in such a way that the electrode layer 31 can be made an air electrode and the counter electrode layer 33 can be made an fuel electrode by changing the configuration. 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-CeO2, or Cu-CeO2 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 make it an air electrode, and hydrogen gas is circulated through the counter electrode layer 33 to make it a fuel electrode, so that the electrochemical element A can be used as a solid oxide fuel cell.

[0143]

[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. That is, 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, the flow of gas to the electrochemical element A needs to be changed. 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.

[0144]

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

[0145]

[12] In the above embodiment, the first through portion 41 and the second through portion 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 portion 41 and the second through portion 51 may be provided at positions other than both ends, or may be provided in two or more pairs. In addition, the first through portion 41 and the second through portion 51 do not need to be provided in pairs. Therefore, one or more first through portion 41 and one or more second through portion 51 may be provided.

[0146]

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

[0147]

[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 communicate between the first and second through-portions 41, 51 to prevent gas leakage. In other words, the first and second annular seal portions 42, 52 may have an endless configuration having an opening therein that communicates with the through-portion and may be configured to seal between adjacent electrochemical elements A. The first and second annular seal portions 42, 52 may be, for example, annular. The annular shape may be any shape, such as a circle, an ellipse, a square, or a polygon.

[0148]

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

[0149]

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

[0150] The configurations disclosed in the above embodiments (including other embodiments) can be applied in combination with configurations disclosed in other embodiments, provided that no contradiction arises. Furthermore, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0151] 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. [Explanation of symbols]

[0152] 1: First plate-like body (support) 1A: Gas flow permitting section 2: Second plate-like body 2c: Recess 2d: Metal oxide layer (metal oxide film) 3a, 3b: Electrochemical reaction section 4: Supply route 5:Exhaust channel 7: Connection 7a: Conductive material 8: Output section 9: Distribution room 10: Plate-shaped support 12: Metal oxide layer (metal oxide film) 31: Electrode layer 32: Electrolyte layer 33: Counter electrode layer 41:First penetration part 42: First annular seal part 51:Second penetration part 52: Second annular seal portion 61: First gas supply section 71: Second gas supply section 80: Sub-channel forming part 81: Partition 100: Electrochemical device 102: Reformer 103:Fuel supply section 104: Inverter A: Electrochemical element A1: Internal flow path A11: Sub-channel A12:Distribution section A13: Merging section A14: Supply adjustment section A14a: Supply passage section A14b: Supply blocking part A15: Supply buffer section A16: Discharge buffer section A17: Discharge adjustment section A17a: Discharge passage section A17b: Discharge prevention part A2: Flow section B: Housing M: Electrochemical module Z: Energy System

Claims

1. 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. 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.

3. 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. 4. The electrochemical device according to claim 1, wherein the plate-like support is made of a metal material.

5. 5. The electrochemical element according to claim 1, wherein the connection portion includes a conductive member.

6. 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. 7. An electrochemical module comprising a plurality of electrochemical elements according to claim 1 arranged in an assembled and electrically connected state.

8. 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.

9. 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 power converter that extracts power from the electrochemical element or the electrochemical module, or that supplies power to the electrochemical element or the electrochemical module.

10. 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.

11. 7. A solid oxide fuel cell comprising the electrochemical element according to claim 1, wherein a power generating reaction occurs in the electrochemical element.

12. 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.

13. 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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