Mesh, water electrolysis device, and fuel cell

Abstract

This mesh is composed of a skeleton comprising a plurality of support parts and a plurality of node parts. Each of the plurality of node parts connects two or more support parts among the plurality of support parts. The skeleton consists of a skeleton body and an internal part surrounded by the skeleton body. The skeleton body consists essentially of nickel or a nickel alloy.

Description

Mesh, water electrolysis device and fuel cell

[0001] The present disclosure relates to a mesh, a water electrolysis device, and a fuel cell. This application claims priority to Japanese Patent Application No. 2023-139548, filed on August 30, 2023, the entire contents of which are incorporated herein by reference.

[0002] Metal meshes have been used in electronic devices, water electrolysis electrodes, and the like (Patent Document 1).

[0003] JP 2009-185378 A

[0004] A mesh according to one aspect of the present disclosure is comprised of a skeleton including a plurality of struts and a plurality of nodes, each of which connects two or more of the struts. The skeleton comprises a skeleton body and an interior portion surrounded by the skeleton body. The skeleton body is essentially made of nickel or a nickel alloy.

[0005] FIG. 1 is a plan view of a mesh according to Embodiment 1. FIG. 2 is an end view of a support portion of the mesh according to Embodiment 1, as viewed from the direction of the arrows II-II in FIG. 1 . FIG. 3 is an end view of a node portion of the mesh according to Embodiment 1, as viewed from the direction of the arrows III-III in FIG. 1 . FIG. 4 is a flowchart of a method for manufacturing a mesh according to Embodiment 1. FIG. 5 is a plan view of a mesh according to Embodiment 2. FIG. 6 is an end view of a mesh according to Embodiment 2, as viewed from the direction of the arrows VI-VI in FIG. 5 . FIG. 7 is a flowchart of a method for manufacturing a mesh according to Embodiment 2. FIG. 8 is a plan view of a mesh according to a first modified example of Embodiment 2. FIG. 9 is a plan view of a mesh according to a second modified example of Embodiment 2. FIG. 10 is a plan view of a mesh according to a third modified example of Embodiment 2. FIG. 11 is a plan view of a mesh according to a fourth modified example of Embodiment 2. FIG. 12 is a plan view of a mesh according to a fifth modified example of Embodiment 2. FIG. 13 is a schematic partial cross-sectional view of a water electrolysis apparatus according to Embodiment 3. FIG. 14 is a schematic partial cross-sectional view of a fuel cell according to Embodiment 4. FIG. 15 is a schematic partial cross-sectional view of a cell of a fuel cell according to a fourth embodiment.

[0006] [Problem to be Solved by the Present Disclosure] In recent years, metal meshes have been used as water electrolysis electrodes. Metal meshes are required to have excellent mechanical strength and low electrical resistance. However, in meshes formed by weaving drawn metal wires, the warp threads (metal wires) and weft threads (metal wires) are only in contact with each other at their intersections. Therefore, it has been difficult to achieve excellent mechanical strength and low electrical resistance with such meshes.

[0007] The present disclosure has been made in view of the above-mentioned problems, and its purpose is to provide a mesh having superior mechanical strength and lower electrical resistance. [Advantages of the present disclosure] According to the present disclosure, it is possible to provide a mesh having superior mechanical strength and lower electrical resistance.

[0008] [Outline of the embodiment of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0009] [1] A mesh according to one aspect of the present disclosure is comprised of a skeleton including a plurality of struts and a plurality of nodes. Each of the plurality of nodes connects two or more of the plurality of struts. The skeleton includes a skeleton body and an interior portion surrounded by the skeleton body. The skeleton body is essentially made of nickel or a nickel alloy.

[0010] In the mesh of the present disclosure, two or more struts are integrated at the nodes, which provides the mesh with better mechanical strength and lower electrical resistance.

[0011] [2] In the above [1], in the central cross section of each of the plurality of node portions along the longitudinal direction of one of the two or more strut portions, a first ratio of the internal minor axis to the internal major axis may be 0.01 or more and 0.9 or less. In the central cross section of one of the strut portions perpendicular to the longitudinal direction, a second ratio of the internal second length to the internal first length may be 0.1 or more and 1.0 or less. The first length is the internal length in the in-plane direction of the mesh in the central cross section of one of the strut portions. The second length is the internal length in the thickness direction of the mesh in the central cross section of one of the strut portions.

[0012] This reduces the surface irregularities of the mesh, prevents the mesh from breaking through a member disposed adjacent to the mesh, and ensures the insulating properties of the insulating member when the member is an insulating member such as a diaphragm of a zero-gap water electrolysis cell.

[0013] [3] In the above [1] or [2], the content of the first atom in the skeletal body may be 0 ppm or more and 100 ppm or less by mass, and the first atom may be at least one atom selected from the group consisting of phosphorus atoms and boron atoms.

[0014] The reducing agent components inevitably mixed in during the reduction of the first atoms lower the melting point of nickel or the melting point of the nickel alloy, so that the mesh has better mechanical strength and lower electrical resistance.

[0015] [4] In any of the above [1] to [3], the interior may be hollow. This allows for a mesh that has superior mechanical strength, lower electrical resistance, and is lighter in weight. Furthermore, rolling the mesh makes it easier to adjust the mesh thickness. This also makes it easier to bring the mesh into close contact with a component adjacent to the mesh (e.g., a diaphragm of a water electrolysis cell).

[0016] [5] In any one of the above [1] to [3], the inner portion may be made of an alkali-resistant resin or an alkali-resistant carbon fiber.

[0017] Therefore, the mesh has superior alkali resistance. Since the interior of the skeleton is solid, the mesh has superior mechanical strength. The mesh can be suitably used as a water electrolysis electrode in a water electrolysis device that uses a strong alkaline solution.

[0018] [6] In the above [5], the alkali-resistant resin may be at least one resin selected from the group consisting of polypropylene, polyethylene, polyester, nylon, and polytetrafluoroethylene.

[0019] Therefore, the mesh has superior alkali resistance. Since the interior of the skeleton is solid, the mesh has superior mechanical strength. The mesh can be suitably used as a water electrolysis electrode in a water electrolysis device that uses a strong alkaline solution.

[0020] [7] In any of the above [1] to [6], the opening ratio of the mesh may be 0.2 percent or more and 80 percent or less.

[0021] The mesh has an opening ratio of 0.2% or more, allowing liquids and gases to pass through. The mesh is suitable for use as a water electrolysis electrode in a water electrolysis device using a strong alkaline solution. Furthermore, the mesh has an opening ratio of 80% or less, providing superior mechanical strength.

[0022] [8] In any of the above [1] to [7], the average circle equivalent diameter of each of the plurality of support portions in a cross section perpendicular to the longitudinal direction of each of the plurality of support portions may be 0.007 mm or more and 0.5 mm or less.

[0023] Therefore, the mesh has superior mechanical strength. [9] In any of the above [1] to [8], the mesh has a main surface on which grooves are formed. The depth of the grooves may be 10% or more of the thickness of the mesh. In a plan view of the main surface, the area of ​​the grooves may be 10% or more of the area of ​​the main surface.

[0024] This improves the uniformity of the flow of fluids such as gases and liquids in the mesh.

[0025]

[10] In the above [9], in the plan view, the mesh has a first edge, a second edge opposite the first edge, a third edge, and a fourth edge opposite the third edge. The third edge and the fourth edge are connected to the first edge and the second edge, respectively. In the plan view, the skeleton may have a lattice shape. Each of the plurality of filaments constituting the lattice may extend from one of the first edge, the second edge, the third edge, and the fourth edge to another of the first edge, the second edge, the third edge, and the fourth edge. The minimum value of the proportion of the length of the portion of each of the plurality of filaments where the grooves are not formed may be 10 percent or more.

[0026] This improves the uniformity of the flow of fluids such as gases and liquids in the mesh.

[0027]

[11] A water electrolysis apparatus according to an aspect of the present disclosure includes a current collector, a diaphragm, and an electrode disposed between the current collector and the diaphragm, wherein at least one of the electrode and the current collector is formed from the mesh according to any one of [1] to

[10] above.

[0028] This improves the uniformity of the flow of the aqueous solution on at least one of the electrodes or the current collectors, and also promotes the discharge of gases generated in the water electrolysis device, thereby improving the performance of the water electrolysis device.

[0029]

[12] A fuel cell according to one aspect of the present disclosure includes a current collector, an electrolyte, and an electrode disposed between the current collector and the electrolyte, wherein the current collector is formed from the mesh according to any one of [1] to

[10] above.

[0030] This improves the uniformity of the gas flow in the current collector, thereby improving the performance of the fuel cell.

[0031] [Details of the Embodiments of the Present Disclosure] The embodiments of the present disclosure will be described below with reference to the drawings. In the drawings of the present disclosure, the same reference numerals represent the same or corresponding parts. Furthermore, dimensional relationships such as length, width, thickness, and depth have been appropriately changed for clarity and simplification of the drawings, and do not necessarily represent actual dimensional relationships.

[0032] (Embodiment 1) A mesh 1 according to embodiment 1 will be described with reference to Figures 1 to 3. Figure 1 is a plan view of the mesh 1. Figure 2 is an end view seen from the direction of the arrows II-II in Figure 1. Figure 3 is an end view seen from the direction of the arrows III-III in Figure 1.

[0033] The mesh 1 is composed of a skeleton 5 having a plurality of strut portions 6 and a plurality of nodes 7. Each of the plurality of nodes 7 connects two or more of the plurality of strut portions 6. The skeleton 5 comprises a skeleton body 2 and an interior portion 3 surrounded by the skeleton body 2. The skeleton body 2 consists essentially of nickel or a nickel alloy.

[0034] Therefore, the mesh 1 has excellent mechanical strength and low electrical resistance. The reason for this is presumably that the skeleton 5 of the mesh 1 has a structure in which multiple hollow metal wires are connected by metallic bonding at each of the multiple node portions 7, rather than a structure in which metal wires are in contact with each other at their intersections.

[0035] <Mesh 1> <Structure of Mesh 1> The mesh 1 according to this embodiment is composed of a skeleton 5 including a plurality of struts 6 and a plurality of node units 7. Each of the plurality of node units 7 connects two or more of the plurality of strut units 6. Each of the plurality of node units 7 may connect three or more of the plurality of strut units 6. Each of the plurality of node units 7 may connect seven or fewer of the plurality of strut units 6, six or fewer of the plurality of strut units 6, five or fewer of the plurality of strut units 6, or four or fewer of the plurality of strut units 6. Each of the plurality of node units 7 may connect two to seven or fewer of the plurality of strut units 6, three to six or fewer of the plurality of strut units 6, three to five or fewer of the plurality of strut units 6, or three to four or fewer of the plurality of strut units 6. Each of the multiple node units 7 may connect three support units 6, four support units 6, five support units 6, six support units 6, or seven support units 6. In the present disclosure, the mesh 1 refers to a mesh-like structure. A mesh-like structure is also called a mesh structure.

[0036] The average equivalent circle diameter of each of the plurality of support portions 6 in a cross section perpendicular to the longitudinal direction of each of the plurality of support portions 6 may be 0.007 mm or more and 0.5 mm or less. This provides the mesh 1 with superior mechanical strength. The lower limit of the average equivalent circle diameter of each of the plurality of support portions 6 may be 0.007 mm or more, 0.01 mm or more, or 0.1 mm or more. The upper limit of the average equivalent circle diameter of each of the plurality of support portions 6 may be 0.5 mm or less, 0.3 mm or less, or 0.2 mm or less. The average equivalent circle diameter of each of the plurality of support portions 6 may be 0.01 mm or more and 0.3 mm or less, or 0.1 mm or more and 0.2 mm or less.

[0037] The average equivalent circle diameter of the support portion 6 in a cross section perpendicular to the longitudinal direction of the support portion 6 can be determined by the following method. A cross section polisher (CP) is used to produce a cross section of the support portion 6 perpendicular to the longitudinal direction of the support portion 6. The cross section of the support portion 6 is then observed with a scanning electron microscope (SEM). Finally, the average value of the equivalent circle diameters of any 10 support portions 6 in the cross section of the support portion 6 is calculated. In this way, the average equivalent circle diameter of the support portion 6 can be determined.

[0038] The opening ratio of the mesh 1 may be 0.2% or more and 80% or less. When the opening ratio of the mesh 1 is 0.2% or more, fluids can easily pass through the mesh 1, and the mesh 1 becomes lighter. When the opening ratio of the mesh 1 is 80% or less, the mesh 1 has better mechanical strength and lower electrical resistance. The lower limit of the opening ratio of the mesh 1 may be 0.2% or more, 6% or more, 10% or more, 20% or more, 25% or more, or 40% or more. The upper limit of the opening ratio of the mesh 1 may be 80% or less, 70% or less, or 60% or less. The opening ratio of the mesh 1 may be 0.2% or more and 70% or less, 60% or more and 80% or less, 6% or more and 70% or less, 10% or more and 70% or less, 20% or more and 70% or less, or 40% or more and 60% or less.

[0039] The opening ratio of the mesh 1 can be measured using the opening ratio measuring device disclosed in Japanese Patent Application Laid-Open No. 2005-290623.

[0040] Referring to FIG. 3 , the thickness T of the mesh 1 is the maximum thickness of the node portion 7. The thickness T of the mesh 1 may be 0.05 mm or more and 0.5 mm or less. This can further increase the mechanical strength of the mesh 1. The lower limit of the thickness T of the mesh 1 may be 0.05 mm or more, 0.1 mm or more, or 0.2 mm or more. The upper limit of the thickness T of the mesh 1 may be 0.5 mm or less, 0.4 mm or less, or 0.3 mm or less. The thickness T of the mesh 1 may be 0.1 mm or more and 0.4 mm or less, or 0.2 mm or more and 0.3 mm or less.

[0041] The thickness T of the mesh 1 can be determined by the following method. First, a digital thickness gauge (Teclock Corporation) is used to measure the thickness of the node portions 7 at any 10 locations on the mesh 1. Then, the average value of the thicknesses of the 10 node portions 7 is calculated. In this way, the thickness T of the mesh 1 is determined.

[0042] The shape of the openings 4 of the mesh 1 is not particularly limited, but may be, for example, a quadrangle, a hexagon, an ellipse, or a triangle. The quadrangle may be, for example, a square, a rectangle, or a diamond.

[0043] In the skeleton 5, the basis weight is 10 g / m ２ More than 1000g / m ２ Therefore, breakage is unlikely to occur (in other words, the skeleton 5 is unlikely to break), and the mesh 1 is easy to bend, so that it can be easily manufactured in continuous plating and heat treatment equipment, and the mesh 1 can be made lighter. ２ or more, and ２ or more, and ２ The upper limit of the basis weight is 800 g / m ２ or less, and ２ or less, and ２ The basis weight can be determined by Archimedes' method.

[0044] The skeleton 5 comprises a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2. This improves the mechanical strength of the mesh 1, reduces the electrical resistance of the mesh 1, and reduces the weight of the mesh 1, particularly when the mesh 1 is used as a water electrolysis electrode. Note that "the skeleton 5 comprises a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2" can also be understood as "in the skeleton 5, the composition of the skeleton main body 2 is different from the composition of the interior 3 surrounded by the skeleton main body 2." Furthermore, "the skeleton 5 comprises a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2" is a concept that also encompasses, for example, a case where the skeleton 5 has an end face and the interior 3 is exposed to the outside of the mesh 1 at the end face of the skeleton 5.

[0045] The fact that "the skeleton 5 is composed of a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2" can be identified by the following method. By observing a cross section perpendicular to the longitudinal direction of the support portion 6 at any one point on the skeleton 5, it is confirmed that "the skeleton 5 is composed of a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2" at that cross section. Next, it is confirmed in the same way at any other four points on the skeleton 5 that "the skeleton 5 is composed of a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2". From the above, it is identified that "the skeleton 5 is composed of a skeleton main body 2 and an interior 3 surrounded by the skeleton main body 2" in the mesh 1.

[0046] <Skeleton Body> The skeleton body 2 is essentially made of nickel or a nickel alloy. This improves the mechanical strength of the mesh 1 and reduces the electrical resistance of the mesh 1. Here, "the skeleton body 2 is essentially made of nickel or a nickel alloy" means that the skeleton body 2 may contain other components besides nickel, as long as the effects of the present disclosure are not impaired. Examples of other components include the first atom described below, cobalt, chromium, tin, copper, and iron. In this embodiment, nickel refers to nickel atoms. The nickel alloy may be at least one alloy selected from the group consisting of a NiCo alloy, a NiCr alloy, a NiSn alloy, a NiCu alloy, and a NiFe alloy.

[0047] The first atom is inevitably contained in a plating solution used in the plating step (S3) described below. In the plating step (S3), the first atom is incorporated into the skeletal body 2. The first atom is, for example, at least one atom selected from the group consisting of a phosphorus atom and a boron atom.

[0048] The content of the first atom in the skeletal body 2 may be 0 ppm or more and 100 ppm or less by mass. Because nickel and the first atom form a eutectic, the melting point of the skeletal body 2 is lower than the melting point of nickel. Therefore, in the heat treatment step (S4) described below, the mesh 1 becomes more flexible, and plating defects in the skeletal body 2 are repaired. The mesh 1 has superior mechanical strength and lower electrical resistance. The lower limit of the content of the first atom in the skeletal body 2 may be 0 ppm or more, 5 ppm or more, or 10 ppm or more by mass. The upper limit of the content of the first atom in the skeletal body 2 may be 100 ppm or less, 50 ppm or less, or 30 ppm or less by mass. The content of the first atom in the skeletal body 2 may be 5 ppm or more and 50 ppm or less, or 10 ppm or more and 30 ppm or less by mass.

[0049] The composition of the skeletal body 2 can be measured by dissolving all of the metal components of the skeletal body 2 and then performing ICP emission spectroscopy and mass spectrometry.

[0050] <Interior> The interior 3 may be hollow. This allows the amount of metal in the skeleton main body 2 to be kept relatively low, and the surface area of ​​the skeleton 5 to be increased. This allows for the provision of a mesh 1 that has superior mechanical strength, lower electrical resistance, and is lighter. Furthermore, since the interior 3 is hollow, the mechanical strength of the mesh 1 in the direction along the diagonal of the rectangle is improved, particularly when the openings 4 are rectangular.

[0051] The fact that the interior 3 is hollow can be identified by the following method: A cross section of the skeleton 5 is taken out by CP. Then, the cross section of the skeleton 5 is observed by SEM. In this way, it can be identified that the interior 3 is hollow.

[0052] The inner portion 3 may be made of an alkali-resistant resin or alkali-resistant carbon fiber, which provides the mesh 1 with superior alkali resistance. The inner portion 3 of the skeleton 5 is solid, which provides the mesh 1 with superior mechanical strength. The mesh 1 can be suitably used as a water electrolysis electrode in a water electrolysis device that uses a strong alkaline solution.

[0053] The alkali-resistant resin may be at least one resin selected from the group consisting of polypropylene, polyethylene, polyester, nylon, and polytetrafluoroethylene. The inner portion 3 may be formed of a material that is more flexible than the skeleton body 2. The inner portion 3 may be formed of a material that has a lower specific gravity than the skeleton body 2. Therefore, a composite material is formed from a metal (i.e., nickel or a nickel alloy) and a resin that is more flexible than the metal (nickel or a nickel alloy). The skeleton 5 is formed of a composite material. Therefore, a mesh 1 that has superior mechanical strength, lower electrical resistance, and is lighter in weight can be provided.

[0054] The alkali-resistant carbon fiber may be at least one type of carbon fiber selected from the group consisting of polyacrylonitrile (PAN)-sintered carbon fiber and pitch-based carbon fiber. This allows a composite material to be formed between the metal (i.e., nickel or a nickel alloy) and the carbon fiber, which is more flexible than the metal (nickel or a nickel alloy). The skeleton 5 is made of the composite material. This allows for a lightweight mesh 1 with superior mechanical strength and lower electrical resistance.

[0055] The fact that the inner portion 3 is made of an alkali-resistant resin or an alkali-resistant carbon fiber can be identified by the following method. First, the mass of the mesh 1 (hereinafter also referred to as the "first mass") is measured. Next, the mesh 1 is immersed in a KOH solution of about 6 mol / L at 70°C for one week. Next, the immersed mesh 1 is washed with water and then dried. Next, the mass of the dried mesh 1 (hereinafter also referred to as the "second mass") is measured. Next, "[{(first mass) - (second mass)} / (first mass)] x 100" is calculated. If "[{(first mass) - (second mass)} / (first mass)] x 100" is 5% or less, it is identified that "the inner portion 3 is made of an alkali-resistant resin or an alkali-resistant carbon fiber."

[0056] The wire diameter of the alkali-resistant carbon fiber may be 0.05 mm or more and 0.5 mm or less. Therefore, it is possible to provide a mesh 1 that has superior mechanical strength, lower electrical resistance, and is lighter. The lower limit of the wire diameter of the alkali-resistant carbon fiber may be 0.05 mm or more, or 0.07 mm or more. The upper limit of the wire diameter of the alkali-resistant carbon fiber may be 0.5 mm or less, 0.2 mm or less, or 0.1 mm or less. The wire diameter of the alkali-resistant carbon fiber may be 0.05 mm or more and 0.2 mm or less, or 0.07 mm or more and 0.1 mm or less.

[0057] The diameter of the alkali-resistant carbon fiber can be determined in accordance with the test method of "Carbon fiber - diameter and cross-sectional area of ​​single fiber" of "JIS R7607:2000."

[0058] The density of the alkali-resistant carbon fiber is 1.7 g / cm ３ 1.9g / cm or more ３ Therefore, it is possible to provide a mesh 1 that has superior mechanical strength, lower electrical resistance, and is lighter in weight. The lower limit of the density of alkali-resistant carbon fibers is 1.79 g / cm. ３ or more, 1.80 g / cm ３ or more, 1.81 g / cm３ The upper limit of the density of the alkali-resistant carbon fiber is 1.9 g / cm ３ or less, 1.85 g / cm ３ or less, 1.83 g / cm ３ The density of the alkali-resistant carbon fiber may be 1.79 g / cm or less. ３ 1.85g / cm or more ３ or less, 1.81 g / cm ３ 1.83g / cm or more ３ It may be the following:

[0059] The density of alkali-resistant carbon fibers can be determined according to the test method for "carbon fiber density" in "JIS R7603:1999."

[0060] 3 , in a cross section at the center of a node 7 along the longitudinal direction of one of two or more struts 6 connected by each of the plurality of node portions 7, a first ratio D2 / D1 of the minor diameter D2 of the interior 3 to the major diameter D1 of the interior 3 may be 0.01 or greater and 0.9 or less. The major diameter D1 of the interior 3 is the length of the interior 3 in the in-plane direction of the mesh 1 in the cross section at the center of the node 7 along the longitudinal direction of the one strut 6. The minor diameter D2 of the interior 3 is the length of the interior 3 in the thickness direction of the mesh 1 in the cross section at the center of the node 7 along the longitudinal direction of the one strut 6.

[0061] 2 , in a central cross section of one of two or more strut sections 6 connected by each of the plurality of node sections 7, which is perpendicular to the longitudinal direction of the one strut section 6, a second ratio D4 / D3 of a second length D4 of the interior section 3 to a first length D3 of the interior section 3 may be 0.1 or greater and 1.0 or less. The first length D3 of the interior section 3 is the length of the interior section 3 in the in-plane direction of the mesh 1 in the central cross section of the one strut section 6. The second length D4 of the interior section 3 is the length of the interior section 3 in the thickness direction of the mesh 1 in the central cross section of the one strut section 6.

[0062] This reduces the surface irregularities of the mesh 1. This prevents members adjacent to the mesh 1 from being torn by the mesh 1. When the member is an insulating member such as a diaphragm of a zero-gap water electrolysis cell, the insulating properties of the insulating member can be ensured. Furthermore, when the interior 3 is hollow, the surface area of ​​the mesh 1 is maintained large, and the node portions 7 are less likely to be damaged. This makes it possible to provide a mesh 1 that has superior mechanical strength, lower electrical resistance, and is lighter in weight.

[0063] The lower limit of the first ratio D2 / D1 may be 0.01 or more, 0.05 or more, or 0.1 or more. The upper limit of the first ratio D2 / D1 may be 0.9 or less, 0.5 or less, or 0.4 or less. The first ratio D2 / D1 may be 0.05 or more and 0.5 or less, or 0.1 or more and 0.4 or less.

[0064] The first ratio D2 / D1 can be determined by the following method. A central cross section of the node portion 7 along the longitudinal direction of one of two or more strut portions 6 connected by each of the multiple node portions 7 is taken using CP. The central cross section of the node portion 7 is then observed using SEM. The average value of the first ratio D2 / D1 at any 10 points on the central cross section of the node portion 7 is calculated. In this way, the first ratio D2 / D1 can be determined.

[0065] The lower limit of the second ratio D4 / D3 may be 0.1 or more, 0.2 or more, or 0.4 or more. The upper limit of the second ratio D4 / D3 may be 1.0 or less, 0.8 or less, or 0.5 or less. The second ratio D4 / D3 may be 0.2 or more and 0.8 or less, or 0.4 or more and 0.5 or less.

[0066] The second ratio D4 / D3 can be determined by the following method. A central cross section of one of two or more strut sections 6 connected by each of a plurality of node sections 7 is taken using CP, the cross section being perpendicular to the longitudinal direction of the strut section 6. The central cross section of the strut section 6 is then observed using SEM. The average value of the second ratio D4 / D3 at any 10 points on the central cross section of the strut section 6 is calculated. In this way, the second ratio D4 / D3 can be determined.

[0067] <Applications> The mesh 1 according to this embodiment can be used as a water electrolysis electrode. The mesh 1 according to this embodiment can also be suitably used in, for example, solid oxide fuel cells, solid oxide steam electrolysis cells, water electrolysis cells, or electromagnetic wave shields. Examples of water electrolysis cells include alkaline water electrolysis cells and anion exchange membrane water electrolysis cells.

[0068] [Method for Manufacturing Mesh 1] A method for manufacturing the mesh 1 according to this embodiment will be described with reference to FIG.

[0069] The method for producing the mesh 1 according to this embodiment includes, for example, a step of preparing a fabric (step S1), a step of obtaining a mesh intermediate (step S2), and a step of plating the surface of the mesh intermediate (step S3), in this order. The method for producing the mesh 1 according to this embodiment may further include a heat treatment step (step S4) after the plating step (step S3). The method for producing the mesh 1 according to this embodiment may further include a rolling step (step S5).

[0070] Step S1: In step S1, a dough is prepared. The dough may be prepared by purchasing a commercially available product, or may be prepared by manufacturing using a conventionally known method.

[0071] The weave of the fabric may be one selected from the group consisting of plain weave, twill weave, satin weave, plain tatami weave, herringbone twill weave, twill tatami weave, honeycomb weave, and 3D fabric weave. The wire diameter of the fabric is not particularly limited, but may be, for example, 0.007 mm or more and 2 mm or less. The mesh size of the fabric is not particularly limited, but may be, for example, 0.004 mm or more and 1 mm or less. The pitch of the fabric is not particularly limited, but may be, for example, 0.007 mm or more and 3 mm or less.

[0072] The fabric may be made of the above-mentioned alkali-resistant resin or alkali-resistant carbon fiber. Carbon fiber is electrically conductive. Therefore, if the fabric is made of alkali-resistant carbon fiber, step S2 described below may be omitted.

[0073] <Step S2> In step S2, a conductive coating layer is formed on the surface of the fabric. For example, a conductive paste is applied to the surface of the fabric. Then, the solvent is evaporated from the conductive paste. In this way, a mesh intermediate is obtained. In the conductive paste, the conductive carbon particles may be 3 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the solvent. Examples of the solvent include water. Examples of the conductive carbon particles include natural graphite and artificial graphite. In this disclosure, "conductive" means "electrically conductive."

[0074] <Step S3> In step S3, plating such as nickel plating is applied to the surface of the mesh intermediate. Plating can be performed by a conventionally known method. In the nickel plating, Ni and Co, Cr, Sn, Cu, or Fe may be plated simultaneously, or Co, Cr, Sn, Cu, or Fe may be plated after nickel plating. A mesh 1 having a skeleton 5 with a bare interior is obtained by steps S1 to S3. Step S4 is performed to obtain a mesh 1 having a skeleton 5 with a hollow interior.

[0075] <Step S4> In step S4, the plated mesh intermediate is heat-treated. This heat treatment removes the base material, leaving the skeleton 5 hollow. The conditions for the heat treatment are not particularly limited, but for example, the heat treatment temperature may be 800°C or higher and 1200°C or lower, and the heat treatment time may be 5 minutes or higher and 60 minutes or lower. In this way, the mesh 1 having the skeleton 5 with a hollow interior is obtained.

[0076] <Step S5> Step S5 is a rolling process carried out to adjust the thickness of the mesh 1. The mesh 1 having the hollow skeleton 5 obtained in step S3, or the mesh 1 having the hollow skeleton 5 obtained in step S4, is rolled. As shown in FIG. 3 , the internal length of the mesh 1 in the thickness direction is reduced, and the thickness of the mesh 1 is reduced. The internal length of the mesh 1 in the thickness direction is smaller than the internal length in the in-plane direction of the mesh 1. In this way, the thickness of the mesh 1 is adjusted.

[0077] EXAMPLES The present embodiment will be described in more detail with reference to examples, although the present embodiment is not limited to these examples.

[0078] <Preparation of Meshes for Samples 1 to 21> Meshes for Samples 1 to 21 were produced by the following method.

[0079] <Fabric Preparation Step> Fabrics made of the resins listed in Table 1 and having the weave, wire diameter, mesh size, and pitch listed in Table 1 were prepared by purchasing commercially available products.

[0080] <Mesh Intermediate Formation Process> A conductive paste was prepared by dispersing artificial graphite (conductive carbon particles) and an acrylic adhesive as raw materials containing carbon atoms in the amount shown in Table 1 in 100 parts by mass of water (solvent). The conductive paste was then applied to the surface of the fabric. The conductive paste was then vacuum-dried at 80°C for 0.1 hours to volatilize the water (solvent) from the conductive paste. A mesh intermediate was thus obtained.

[0081] <Plating Step> The mesh intermediate was subjected to nickel plating using the following plating bath composition and electrolysis conditions to obtain a mesh.

[0082] (Plating bath composition) Salt (aqueous solution): Nickel sulfamate (plating bath contains nickel at the concentration shown in Table 2) Boric acid: As shown in Table 2 pH: As shown in Table 2 (Electrolysis conditions) Temperature: 60°C Current density: 10 A / dm ２ Anode: Nickel pellet anode Time: Adjusted according to the metal type and coating weight.

[0083] <Heat Treatment Step> Meshes according to Samples 1 to 20, among the meshes according to Samples 1 to 21, were heat treated under the temperature and time conditions shown in Table 2 to obtain meshes according to Samples 1 to 20, each having a hollow skeleton 5. The heat treatment step includes a roasting step in which the resin is burned in an air atmosphere, and a reduction step in which the metal components on the surface of the skeleton oxidized in the roasting step are reduced in a reducing atmosphere. Note that "-" in the "Temperature [°C]" and "Time [min]" columns of the "Heat Treatment Step" column in Table 2 means that the heat treatment step was not performed.

[0084] As a result of the above, "meshes composed of a skeleton having a plurality of struts and node portions connecting the struts in the number listed in Table 3" relating to samples 1 to 21 were manufactured.

[0085] <Preparation of Mesh for Sample 101> A nickel mesh (weight: 370 g / m) manufactured by Taiyo Wire Mesh Co., Ltd. ２ The mesh for Sample 101 was prepared by purchasing a nickel mesh (pitch: 0.75 mm, wire diameter: 0.15 mm, mesh size: 0.6 mm, weave: plain weave). In Sample 101, the nickel wires simply cross each other, and are not connected to each other by metallic bonding. Therefore, in Sample 101, no nodes are formed, and no support posts are also present to connect the nodes (see Table 3).

[0086] <<Preparation of Mesh for Sample 102>> A "mesh composed of a skeleton having a plurality of struts and nodes connecting the struts in the number shown in Table 3" for Sample 102 was prepared by the following method. First, a plating amount of 130 g / m was applied to the mesh of Sample 101. ２ Nickel plating was carried out under the following plating bath composition and electrolysis conditions so as to obtain the above.

[0087] (Plating bath composition) Salt (aqueous solution): Nickel sulfamate (plating bath contains nickel at 90 g / L) Boric acid: 20 g / L pH: 4 (Electrolysis conditions) Temperature: 60°C Current density: 10 A / dm ２ Anode: Nickel pellet anode Time: Adjusted according to the metal type and coating weight.

[0088] Next, heat treatment was performed under conditions of 1000°C for 30 minutes to obtain "a mesh composed of a skeleton having a plurality of support portions and node portions connecting the number of support portions listed in Table 3" according to sample 102.

[0089] <<Preparation of Mesh for Sample 103>> The mesh for Sample 103 was prepared by the following method. First, a conductive paste was prepared by dispersing 10 parts by mass of artificial graphite (conductive carbon particles) as a carbon atom-containing raw material in 100 parts by mass of water (solvent) using an acrylic adhesive. Next, the conductive paste was applied to the surface of a polypropylene monofilament having a wire diameter of 180 μm. Next, the conductive paste was vacuum-dried at 80°C for 0.1 hours. The water (solvent) was evaporated from the conductive paste to obtain a conductive monofilament. Next, the conductive monofilament was nickel-plated using the plating bath composition and electrolysis conditions below to achieve an average plating thickness of 5 μm. The average plating thickness was determined by measuring the shortest distance from the surface of the monofilament to the plating surface at any five locations on the cross section perpendicular to the longitudinal direction of the nickel-plated conductive monofilament, and then calculating the average of the five shortest distances.

[0090] (Plating bath composition) Salt (aqueous solution): Nickel sulfamate (plating bath contains nickel at 90 g / L) Boric acid: 20 g / L pH: 4 (Electrolysis conditions) Temperature: 60°C Current density: 10 A / dm ２ Anode: Nickel pellet anode Time: Adjusted according to the metal type and coating weight.

[0091] Next, the nickel-plated monofilaments were plain woven to obtain a mesh intermediate having the following pitch and mesh openings. The mesh intermediate was then heat-treated at 1000°C for 30 minutes to obtain the mesh of Sample 103. In Sample 103, the nickel-plated monofilaments merely cross each other, and are not connected to each other by metallic bonding. Therefore, Sample 103 does not have any nodes, nor any struts connecting the nodes (see Table 3).

[0092]

[0093]

[0094]

[0095] <Mesh characteristic evaluation> <Skeleton structure> The presence or absence of a "skeleton consisting of a skeleton main body and an interior surrounded by the skeleton main body" was identified using the method described above. The results obtained are shown in the "Presence or absence of skeleton main body + interior" column in Table 3.

[0096] <Composition of Skeleton Main Body> The nickel content in the skeleton main body was determined by the method described above. The results obtained are shown in the "Ni content [mass %]" column of the "Skeleton main body" column in Table 3. In addition, the content of the first atom in the skeleton main body was determined by the method described above. The results obtained are shown in the "First atom content [mass %]" column of the "Skeleton main body" column in Table 3.

[0097] <First ratio D2 / D1 and second ratio D4 / D3> In a central cross section of a node along the longitudinal direction of one of two or more struts connected by each of the multiple node sections, a first ratio D2 / D1 of the internal minor diameter D2 to the internal major diameter D1 was determined using the method described above. The results obtained are shown in the "D2 / D1" column of Table 3. Furthermore, in a central cross section of one of two or more struts connected by each of the multiple node sections, perpendicular to the longitudinal direction of the one of the strut sections, a second ratio D4 / D3 of the internal second length D4 to the internal first length D3 was determined using the method described above. The results obtained are shown in the "D4 / D3" column of Table 3.

[0098] <Opening ratio of mesh> The opening ratio of the mesh was determined by the method described above. The results are shown in the column "Opening ratio of mesh [%]" in Table 3.

[0099] <Average circular equivalent diameter of the support portion in a cross section perpendicular to the longitudinal direction of the support portion> The average circular equivalent diameter of the support portion in a cross section perpendicular to the longitudinal direction of the support portion was determined by the method described above. The results obtained are shown in the column "Average circular equivalent diameter [mm]" in Table 3.

[0100] <Mechanical strength of mesh> The mechanical strength of the mesh was determined using an "Autograph AGX-10NVD" (trademark) manufactured by Shimadzu Corporation. The results obtained are shown in the "Mechanical strength [N / 10 mm]" column of Table 4. A relatively high value shown in the "Mechanical strength [N / 10 mm]" column of Table 4 means that the mechanical strength of the mesh is excellent.

[0101] The meshes of Samples 1 to 21 correspond to examples of this embodiment. The meshes of Samples 101 to 103 correspond to comparative examples. It was found that the meshes of Samples 1 to 21 have significantly superior mechanical strength compared to the meshes of Samples 101 to 103.

[0102] <Mesh Electrical Resistance> The mesh electrical resistance was determined using the following method. For each sample, a square mesh with a side length of 5 cm was prepared. A portion of the square mesh located 5 mm inward from a first corner of the mesh in both the vertical and horizontal directions was clamped with a first clip terminal. A portion of the square mesh located 5 mm inward from a second corner of the square mesh diagonally opposite the first corner was clamped with a second clip terminal. A current was passed between the first and second clip terminals, and the mesh electrical resistance was measured using a "BT3562 BATTERY HiTESTER" manufactured by Hioki E.E. Corporation. The results obtained in this manner are shown in the "Electrical Resistance [mΩ]" column of Table 4. A relatively low value listed in the "Electrical Resistance [mΩ]" column of Table 4 indicates that the mesh had a relatively low electrical resistance. It was found that the meshes of Samples 1 to 21 had significantly lower electrical resistance than the meshes of Samples 101 and 103.

[0103] <Basis Weight of Skeleton> The basis weight of the skeleton was determined by the method described above. The results obtained are shown in Table 4 as "Basis Weight [g / m ２ ]" column. A relatively low basis weight of the skeleton means that the mesh is relatively light. It was found that the meshes of Samples 1 to 21 were significantly lighter than the mesh of Sample 102.

[0104] <Insulation evaluation test> The insulation property of the membrane sandwiched between two meshes was evaluated by the following method. First, a 20 μm-thick polyethylene (PE) membrane was sandwiched between two meshes to obtain a laminate. The PE membrane has insulating properties. Next, a 10 t / cm ２The electrical resistance of the laminate was measured by applying a pressure of 0.05 MPa to the two meshes and passing a current between them. The insulating properties of the diaphragm sandwiched between the two meshes were evaluated based on the following evaluation criteria. Evaluation criterion A was assigned when the electrical resistance of the laminate was 10 MΩ or higher. Evaluation criterion B was assigned when the electrical resistance of the laminate was 100 kΩ or higher but less than 10 MΩ. Evaluation criterion C was assigned when the electrical resistance of the laminate was less than 100 kΩ. The results are shown in the "Insulating Properties" column in Table 4. In the present disclosure, insulating properties refer to the resistance of the diaphragm to electrical leakage. When a "short circuit" state occurs between the two meshes, electrical leakage is more likely to occur in the diaphragm, and the insulating properties of the diaphragm are reduced. Evaluation criterion A or B means that the diaphragm is not broken by the meshes even when pressure is applied to the laminate, and the insulating properties of the diaphragm sandwiched between the two meshes are ensured.

[0105] (Evaluation criteria) A: No short circuit B: Minor short circuit C: Short circuit

[0106]

[0107] It was found that the insulating properties of the diaphragm sandwiched between two meshes according to Samples 1 to 21 were superior to the insulating properties of the diaphragm sandwiched between two meshes according to Samples 101 and 102. The reason for this is that the meshes according to Samples 1 to 21 have reduced mesh surface irregularities, so that even when a laminate of the mesh and the diaphragm is pressurized, the diaphragm (for example, the diaphragm of a zero-gap water electrolysis cell) is prevented from being broken by the mesh.

[0108] From the above, it was found that the meshes according to Samples 1 to 21 have excellent mechanical strength and low electrical resistance. It was also found that the meshes according to Samples 1 to 21 can ensure the insulation of an insulating member (e.g., a diaphragm) sandwiched between two meshes.

[0109] (Embodiment 2) A mesh 1 of embodiment 2 will be described with reference to Figures 5 and 6. The mesh 1 of this embodiment has the same configuration as the mesh 1 of embodiment 1, but differs from the mesh 1 of embodiment 1 in that the mesh 1 of this embodiment has a plurality of grooves 17.

[0110] The mesh 1 has a main surface 10a and a main surface 10b opposite to the main surface 10a. The main surfaces 10a and 10b are spaced apart in the thickness direction of the mesh 1. In a plan view, the mesh 1 has a first edge 11, a second edge 12 opposite to the first edge 11, a third edge 13, and a fourth edge 14 opposite to the third edge 13. The third edge 13 and the fourth edge 14 are connected to the first edge 11 and the second edge 12, respectively. In this specification, unless otherwise specified, a plan view refers to a plan view of the main surface 10a shown in FIG. 5.

[0111] In a plan view, the skeleton 5 has a lattice shape. In this embodiment, the lattice is a square lattice, but it may also be a triangular lattice, a hexagonal lattice, or the like. The plurality of filaments 15 constituting the lattice each extend from one of the first edge 11, the second edge 12, the third edge 13, and the fourth edge 14 to another of the first edge 11, the second edge 12, the third edge 13, and the fourth edge 14. When the skeleton 5 has a square lattice shape as shown in FIG. 5 , the plurality of filaments 15 are composed of a plurality of first filaments 15 a and a plurality of second filaments 15 b, and the lattice is formed by the plurality of first filaments 15 a and the plurality of second filaments 15 b. Each of the plurality of first filaments 15 a extends from the first edge 11 to the second edge 12. Each of the plurality of second filaments 15 b extends from the third edge 13 to the fourth edge 14.

[0112] A plurality of grooves 17 are formed on the main surface 10a of the mesh 1. For example, each of the plurality of grooves 17 is a long, narrow, linear groove. The plurality of grooves 17 are parallel to one another. In a plan view, the plurality of grooves 17 extend in the same direction. Each of the plurality of grooves 17 extends from the first edge 11 to the second edge 12. The longitudinal direction of each of the plurality of grooves 17 may be parallel to the longitudinal direction of the second filament 15b. Each of the plurality of grooves 17 may extend parallel to the second filament 15b.

[0113] Each of the multiple grooves 17 has a depth d and a width W. The depth d is given by the difference between the height of the node portion 7 in an area of ​​the mesh 1 where the multiple grooves 17 are not formed and the height of the node portion 7 within the groove 17. The depth d may be 10 percent or more of the thickness T of the mesh 1, or may be 30 percent or more of the thickness T of the mesh 1. The depth d may be 90 percent or less of the thickness T of the mesh 1. In this embodiment, the thickness T of the mesh 1 is the thickness of the center of the node portion 7 where the multiple grooves 17 are not formed. In a plan view, the area of ​​the multiple grooves 17 may be 10 percent or more of the area of ​​the main surface 10a, or may be 30 percent or more of the area of ​​the main surface 10a. In a plan view, the area of ​​the multiple grooves 17 may be 90 percent or less of the area of ​​the main surface 10a. In this specification, the area of ​​the multiple grooves 17 means the total area of ​​the multiple grooves 17 in a plan view.

[0114] A method for manufacturing the mesh 1 of this embodiment will be described with reference to Fig. 7. The method for manufacturing the mesh 1 of this embodiment includes the same steps as the method for manufacturing the mesh 1 of embodiment 1 shown in Fig. 4, but differs from the method for manufacturing the mesh 1 of embodiment 1 in that the method for manufacturing the mesh 1 of this embodiment further includes a groove forming step (step S6).

[0115] The groove forming step (step S6) is performed after the rolling step (step S5). In the groove forming step (step S6), a plurality of grooves 17 are formed on the main surface 10a. Specifically, a mold (not shown) is pressed against the main surface 10a of the mesh 1. The shape of the convex portions of the mold is transferred to the main surface 10a. In this way, the mesh 1 having a plurality of grooves 17 formed on the main surface 10a is obtained.

[0116] A mesh 1 according to a first modified example of this embodiment will be described with reference to FIG. 8 . In the mesh 1 according to this modified example of this embodiment, the grooves 17 are each inclined relative to the first filaments 15 a and the second filaments 15 b. In a further modified example of this embodiment, the grooves 17 may be formed concentrically in a plan view. The grooves 17 may be formed spirally in a plan view. As shown in FIG. 9 , the grooves 17 may be formed radially in a plan view. As shown in FIG. 10 , the grooves 17 may be spaced apart from the first edge 11, the second edge 12, the third edge 13, and the fourth edge 14 in a plan view, and the grooves 17 may be arranged in a lattice pattern.

[0117] 11 and 12 , in a plan view, the plurality of grooves 17 may be formed by a plurality of first grooves 17 a and a plurality of second grooves 17 b intersecting the plurality of first grooves 17 a. As shown in Fig. 11 , in a plan view, the plurality of first grooves 17 a may be parallel to the plurality of first umbilical members 15 a, and the plurality of second grooves 17 b may be parallel to the plurality of second umbilical members 15 b. As shown in Fig. 12 , in a plan view, the plurality of first grooves 17 a may be inclined with respect to the plurality of first umbilical members 15 a and the plurality of second umbilical members 15 b, and the plurality of second grooves 17 b may be inclined with respect to the plurality of first umbilical members 15 a and the plurality of second umbilical members 15 b.

[0118] In the above-described modified examples of this embodiment (see, for example, the modified examples shown in FIGS. 8 , 10 , and 12 ), each of the plurality of filaments 15 has a portion where the plurality of grooves 17 are not formed (hereinafter, sometimes referred to as a “non-groove portion”). The minimum value of the length ratio of the non-groove portion of each of the plurality of filaments 15 is 10% or more. This improves the mechanical strength of the mesh 1. The minimum value of the length ratio of the non-groove portion of each of the plurality of filaments 15 may be 30% or more, or may be 50% or more. In this specification, the minimum value of the length ratio of the non-groove portion of each of the plurality of filaments 15 refers to the minimum value of the calculated length ratio of the non-groove portion of each of the plurality of filaments 15, calculated by dividing the length of the non-groove portion of each of the plurality of filaments 15 by the total length of each of the plurality of filaments 15.

[0119] EXAMPLES The present embodiment will be described in more detail with reference to examples, although the present embodiment is not limited to these examples.

[0120] The mesh of Sample 34 is similar to the mesh of Sample 1 of Example 1 (see Tables 1 to 4), but has the number of openings and thickness T shown in Table 5. The number of openings in the mesh is the number of openings per inch (2.54 cm) of length. Sample 34 does not have multiple grooves 17.

[0121] The mesh of sample 31 is similar to the mesh of sample 34, but has a plurality of grooves 17 formed on the main surface 10a of the mesh as shown in Figure 5. The depth d and width of each of the plurality of grooves 17, as well as the spacing between adjacent grooves 17, are as shown in Table 5. In the mesh of sample 31, the plurality of grooves 17 extend parallel to the second filaments 15b, and therefore the minimum value of the proportion of the non-grooved portion of each of the plurality of filaments 15 is zero.

[0122] The meshes of Samples 32 and 33 are similar to the mesh of Sample 31, but in the meshes of Samples 32 and 33, a plurality of grooves 17 as shown in FIG. 8 are formed on the main surface 10a of the mesh. The plurality of grooves 17 are each inclined with respect to the plurality of first filaments 15a and the plurality of second filaments 15b. The minimum value of the proportion of the non-groove portions of each of the plurality of filaments 15 in the mesh of Sample 32 and the minimum value of the proportion of the non-groove portions of each of the plurality of filaments 15 in the mesh of Sample 33 are as shown in Table 5.

[0123] A solid oxide fuel cell (SOFC) was fabricated, in which the anode current collector was formed using the mesh according to one of Samples 31 to 34, and the power generation performance and heat cycle characteristics of the SOFC were measured. The fabricated SOFC included an anode interconnector, a cathode interconnector, a solid electrolyte, a cathode, an anode, an anode current collector, and a cathode current collector.

[0124] The anode interconnector and the cathode interconnector are formed of an iron-chromium alloy. The solid electrolyte is disposed between the anode interconnector and the cathode interconnector. The solid electrolyte is formed of yttria-stabilized zirconia (YSZ). The anode is disposed between the anode interconnector and the solid electrolyte. The anode is a porous body formed of a composite of nickel (Ni) and yttria-stabilized zirconia (YSZ). The cathode is disposed between the cathode interconnector and the solid electrolyte. The cathode is a porous body formed of lanthanum strontium cobaltite (LSC). The anode current collector is disposed between the anode interconnector and the anode. The anode current collector is formed of a mesh according to one of Samples 31 to 34. The cathode current collector is disposed between the cathode interconnector and the cathode. The cathode current collector is formed of silver paste.

[0125] The prototype SOFC was heated to a temperature of 760°C. Then, 0.4 L / min of hydrogen and 0.6 L / min of air were flowed into the SOFC. The power generation performance of the SOFC was measured. The heat cycle characteristics of the SOFC were also measured as follows. A current of 0.4 A / cm was applied to the SOFC. ２ While passing a current of 100 kJ / s, the SOFC is subjected to 20 heat cycles. In each heat cycle, the temperature of the SOFC is changed between 50°C and 760°C. The temperature increase and decrease rates in each heat cycle are 30°C / min. A first output voltage of the SOFC at a temperature of 760°C in the first cycle is measured. A second output voltage of the SOFC at a temperature of 760°C in the 20th cycle is measured. The heat cycle characteristics of the SOFC are obtained by expressing the ratio of the second output voltage to the first output voltage as a percentage.

[0126] The power generation performance and heat cycle characteristics of the prototype SOFCs are shown in Table 5. The power generation performance of the SOFCs in which the anode current collector is formed using the mesh of one of Samples 31 to 33 is higher than the power generation performance of the SOFC in which the anode current collector is formed using the mesh of Sample 34. This is because the provision of multiple grooves 17 in the anode current collector reduces gas pressure loss in the anode current collector and improves the uniformity of gas flow in the anode current collector.

[0127] The heat cycle characteristics of an SOFC in which the anode current collector is formed from the mesh of one of Samples 32 and 33 are superior to the heat cycle characteristics of an SOFC in which the anode current collector is formed from the mesh of Sample 31. This is because the minimum value of the non-grooved portion of the mesh of each of Samples 32 and 33 is greater than the minimum value of the non-grooved portion of the mesh of Sample 31, and the mesh of each of Samples 32 and 33 has improved mechanical strength compared to the mesh of Sample 31.

[0128]

[0129] 13 , a water electrolysis apparatus 20 according to a third embodiment will be described. The water electrolysis apparatus 20 is, for example, a zero-gap alkaline water electrolysis apparatus. The water electrolysis apparatus 20 includes bipolar plates 21 and 22, a spacer 23, a diaphragm 30, an anode 31, a cathode 32, a conductive elastic body 33, current collectors 34 and 35, and conductive ribs 36 and 37.

[0130] The bipolar plates 21 and 22 are flat plate-shaped members and are made of, for example, an iron-chromium alloy.

[0131] The spacer 23 is disposed between the bipolar plates 21 and 22. The spacer 23 defines the gap between the bipolar plates 21 and 22. The spacer 23 is formed of an insulating material such as polytetrafluoroethylene (PTFE). The diaphragm 30, the anode 31, the cathode 32, the conductive elastic body 33, and the current collectors 34 and 35 are housed in the internal space defined by the bipolar plates 21 and 22 and the spacer 23.

[0132] The diaphragm 30 is disposed between the bipolar plates 21 and 22. The diaphragm 30 is supported by the spacer 23. The diaphragm 30 divides the internal space defined by the bipolar plates 21, 22 and the spacer 23 into an anode chamber 28 and a cathode chamber 29. The diaphragm 30 is an insulator and is permeable to ions such as hydroxide ions. The diaphragm 30 is formed of, for example, polyphenylene sulfide (PPS).

[0133] The spacer 23 is provided with inlets 24, 25 and outlets 26, 27. The inlet 24 and outlet 26 are connected to an anode chamber 28. The inlet 25 and outlet 27 are connected to a cathode chamber 29. An alkaline aqueous solution flows into the anode chamber 28 from the inlet 24 and into the cathode chamber 29 from the inlet 25. The alkaline aqueous solution is, for example, a potassium hydroxide (KOH) aqueous solution or a sodium hydroxide (NaOH) aqueous solution. Oxygen and the alkaline aqueous solution generated at the anode 31 flow out from the outlet 26. Hydrogen and the alkaline aqueous solution generated at the cathode 32 flow out from the outlet 27.

[0134] The anode 31, the current collector 34, and the conductive rib 36 are disposed in the anode chamber 28. The cathode 32, the conductive elastic body 33, the current collector 35, and the conductive rib 37 are disposed in the cathode chamber 29.

[0135] The anode 31 is disposed between the bipolar plate 21 and the diaphragm 30. The anode 31 may be in contact with the diaphragm 30. The cathode 32 is disposed between the bipolar plate 22 and the diaphragm 30. The cathode 32 may be in contact with the diaphragm 30. The conductive elastic body 33 is disposed between the cathode 32 and the bipolar plate 22. The conductive elastic body 33 is in contact with the cathode 32.

[0136] The current collector 34 is disposed between the bipolar plate 21 and the anode 31. The current collector 34 is in contact with the anode 31. The current collector 34 is pressed against the anode 31 by a conductive rib 36 protruding from the bipolar plate 21. The current collector 35 is disposed between the bipolar plate 22 and the cathode 32. The current collector 35 is in contact with the cathode 32. The current collector 35 is pressed against the cathode 32 by a conductive rib 37 protruding from the bipolar plate 22.

[0137] At least one of the anode 31, the cathode 32, the current collector 34, and the current collector 35 is formed from the mesh 1 according to any one of the first embodiment, the second embodiment, and their modifications.

[0138] The operation of the water electrolysis device 20 will be described. An alkaline aqueous solution is supplied to the anode chamber 28 and the cathode chamber 29 of the water electrolysis device 20 through the inlets 24 and 25. A voltage is applied between the bipolar plates 21 and 22 so that the potential of the cathode 32 is lower than the potential of the anode 31. At the cathode 32, water is reduced to generate hydrogen gas and hydroxide ions. The hydroxide ions migrate from the cathode 32 to the anode 31 through the diaphragm 30. At the anode 31, hydroxide ions contained in the alkaline aqueous solution are oxidized to generate oxygen gas. The oxygen generated at the anode 31 and the alkaline aqueous solution flow out from the outlet 26. The hydrogen generated at the cathode 32 and the alkaline aqueous solution flow out from the outlet 27.

[0139] The water electrolysis device 20 is not limited to an alkaline water electrolysis device, and may be an anion exchange membrane water electrolysis device or the like.

[0140] The effects of the water electrolysis apparatus 20 of this embodiment will be described. The water electrolysis apparatus 20 of this embodiment includes a current collector (current collector 34 or current collector 35), a diaphragm 30, and an electrode (anode 31 or cathode 32) disposed between the current collector and the diaphragm. At least one of the electrodes or the current collector is formed from the mesh 1 of any one of Embodiment 1, Embodiment 2, and their modifications.

[0141] This improves the uniformity of the flow of the aqueous solution on at least one of the electrodes or the current collectors, and also promotes the discharge of gases generated within the water electrolysis device 20. This improves the performance of the water electrolysis device 20.

[0142] (Embodiment 4) A fuel cell 40 of embodiment 4 will be described with reference to Figures 14 and 15. The fuel cell 40 of this embodiment is, for example, a solid oxide fuel cell (SOFC). With reference to Figure 14, the fuel cell 40 includes interconnectors 41 and 42, an anode current collector 43, a cell 44, a cathode current collector 49, and a spacer 50. Although not shown, the fuel cell 40 has a cell stack structure formed by stacking unit structures each including the interconnectors 41 and 42, the anode current collector 43, the cell 44, the cathode current collector 49, and the spacer 50.

[0143] The interconnectors 41 and 42 are flat plate-shaped members. The interconnector 41 is made of, for example, an iron-chromium alloy. Although not shown, the interconnector 42 is electrically connected to the interconnector 41. A groove 41a may be formed in the surface of the interconnector 41 facing the anode current collector 43. A groove 42a may be formed in the surface of the interconnector 42 facing the cathode current collector 49. The interconnector 41 is provided with an inlet 41b and an outlet (not shown). The interconnector 42 is provided with an inlet 42b and an outlet (not shown).

[0144] The spacer 50 is disposed between the interconnector 41 and the interconnector 42. The spacer 50 defines the gap between the interconnector 41 and the interconnector 42. The spacer 50 is formed of an insulating material such as mica. An anode current collector 43, a cell 44, and a cathode current collector 49 are housed in the internal space defined by the interconnectors 41, 42 and the spacer 50.

[0145] The cell 44 is disposed between the interconnector 41 and the interconnector 42. The anode current collector 43 is disposed between the interconnector 41 and the cell 44. The cathode current collector 49 is disposed between the interconnector 42 and the cell 44. The cell 44 is disposed between the anode current collector 43 and the cathode current collector 49.

[0146] 15, a cell 44 includes an anode 45, a solid electrolyte 46, and a cathode 48. The cell 44 may further include an intermediate layer 47.

[0147] The fuel electrode 45 is a sheet-like porous body. The porous body constituting the fuel electrode 45 is made of, for example, zirconia (ZrO ２ The anode 45 may be formed by applying a conductive material to the anode current collector 43.

[0148] The solid electrolyte 46 is disposed between the anode 45 and the cathode 48. The solid electrolyte 46 is in contact with the anode 45. The solid electrolyte 46 is a sheet-like member that allows oxygen ions to pass through. The solid electrolyte 46 is formed of, for example, yttria-stabilized zirconia (YSZ).

[0149] The air electrode 48 is a flat porous body. The porous body constituting the air electrode 48 is, for example, (La, Sr)MnO ３ or (La,Sr)CoO ３ The cathode 48 may be formed by applying a conductive material to the cathode current collector 49. If the cell 44 does not include the intermediate layer 47, the cathode 48 is in contact with the solid electrolyte 46. If the cell 44 includes the intermediate layer 47, the cathode 48 is in contact with the intermediate layer 47.

[0150] The intermediate layer 47 is disposed between the solid electrolyte 46 and the air electrode 48. The intermediate layer 47 prevents a reaction between the solid electrolyte 46 and the air electrode 48. The intermediate layer 47 is formed of, for example, a Gd-doped Ce oxide (GDC).

[0151] The anode current collector 43 is disposed between the interconnector 41 and the cell 44 (more specifically, the anode 45). The anode current collector 43 is in contact with the interconnector 41 and the cell 44 (more specifically, the anode 45). The cathode current collector 49 is disposed between the interconnector 42 and the cell 44 (more specifically, the cathode 48). The cathode current collector 49 is in contact with the interconnector 42 and the cell 44 (more specifically, the cathode 48).

[0152] In the fuel cell 40 of this embodiment, at least one of the anode current collector 43 or the cathode current collector 49 is formed from the mesh 1 of any one of the first embodiment, second embodiment, and their modifications.

[0153] The operation of the fuel cell 40 will now be described. Fuel gas is supplied to the anode current collector 43 and the anode 45 through the inlet 41b. The fuel gas may be, for example, hydrogen (H ２ The fuel gas passes through the grooves 41 a and is spread over the entire anode current collector 43 and the entire anode 45 .

[0154] Oxygen gas is supplied to the cathode current collector 49 and the cathode 48 through the inlet 42b. The oxygen gas passes through the grooves 42a and is spread over the entire cathode current collector 49 and the entire cathode 48. Oxygen ions move from the cathode 48 to the anode 45 through the solid electrolyte 46. The oxygen ions that reach the anode 45 react with hydrogen gas supplied to the anode 45 through the anode current collector 43. As a result, water (H ２ O and electrons are generated. These electrons are supplied to the air electrode 48 through the interconnector 41, the interconnector 42, and the air electrode current collector 49, and ionize the oxygen gas supplied to the air electrode 48 through the air electrode current collector 49. The above reaction is repeated, and the fuel cell 40 generates electricity.

[0155] The effects of the fuel cell 40 of this embodiment will be described. The fuel cell 40 of this embodiment includes a current collector (anode current collector 43 or cathode current collector 49), an electrolyte (solid electrolyte 46), and an electrode (anode 45 or cathode 48) disposed between the current collector and the electrolyte. The current collector is formed of the mesh 1 of any of the first and second embodiments and their modifications.

[0156] This reduces the pressure loss of the gas in the current collector, improving the uniformity of the gas flow in the current collector, thereby improving the performance of the fuel cell 40.

[0157] The disclosed embodiments 1 to 4 are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims rather than the above-described embodiments, and it is intended to include meanings equivalent to the claims and all modifications within the scope thereof.

[0158] REFERENCE SIGNS LIST 1 mesh, 2 skeleton body, 3 interior, 4 opening, 5 skeleton, 6 support portion, 7 node portion, 10a, 10b main surface, 11 first edge, 12 second edge, 13 third edge, 14 fourth edge, 15 filament, 15a first filament, 15b second filament, 17 groove, 17a first groove, 17b second groove, 20 water electrolysis device, 21, 22 bipolar plate, 23 spacer, 24, 25, 41b, 42b inlet, 26, 27 outlet, 28 anode chamber, 29 cathode chamber, 30 diaphragm, 31 anode, 32 cathode, 33 conductive elastic body, 34, 35 current collector, 36, 37 conductive rib, 40 fuel cell, 41, 42 interconnector, 41a, 42a groove, 43 Anode current collector, 44 cell, 45 anode, 46 solid electrolyte, 47 intermediate layer, 48 cathode, 49 cathode current collector, 50 spacer.

Claims

1. A mesh comprising a skeleton having a plurality of strut portions and a plurality of nodes, each of the plurality of nodes connecting two or more of the plurality of strut portions, the skeleton comprising a skeleton body and an interior surrounded by the skeleton body, the skeleton body consisting essentially of nickel or a nickel alloy.

2. A mesh as described in claim 1, wherein, in a central cross-section of each of the multiple node portions along the longitudinal direction of one of the two or more support portions, a first ratio of the internal minor axis to the internal major axis is 0.01 or more and 0.9 or less, and, in a central cross-section of the one of the support portions perpendicular to the longitudinal direction, a second ratio of the internal second length to the internal first length is 0.1 or more and 1.0 or less, the first length being the internal length in the in-plane direction of the mesh in the central cross-section of the one of the support portions, and the second length being the internal length in the thickness direction of the mesh in the central cross-section of the one of the support portions.

3. A mesh as described in claim 1 or claim 2, wherein the content of the first atom in the skeletal body is from 0 ppm to 100 ppm by mass, and the first atom is at least one type of atom selected from the group consisting of phosphorus atoms and boron atoms.

4. A mesh as claimed in any one of claims 1 to 3, wherein the interior is hollow.

5. A mesh as claimed in any one of claims 1 to 3, wherein the interior is made of an alkali-resistant resin or an alkali-resistant carbon fiber.

6. The mesh according to claim 5, wherein the alkali-resistant resin is at least one resin selected from the group consisting of polypropylene, polyethylene, polyester, nylon, and polytetrafluoroethylene.

7. A mesh according to any one of claims 1 to 6, wherein the opening ratio of the mesh is between 0.2 percent and 80 percent.

8. A mesh described in any one of claims 1 to 7, wherein the average circular equivalent diameter of each of the plurality of support portions in a cross section perpendicular to the longitudinal direction of each of the plurality of support portions is 0.007 mm or more and 0.5 mm or less.

9. A mesh as claimed in any one of claims 1 to 8, wherein the mesh has a main surface having grooves formed therein, the depth of the grooves being 10 percent or more of the thickness of the mesh, and the area of ​​the grooves in a plan view of the main surface being 10 percent or more of the area of ​​the main surface.

10. The mesh described in claim 9, wherein, in the planar view, the mesh has a first edge, a second edge opposite the first edge, a third edge, and a fourth edge opposite the third edge, the third edge and the fourth edge being connected to the first edge and the second edge, respectively; in the planar view, the skeleton has a lattice shape, and each of the multiple filaments constituting the lattice extends from one of the first edge, the second edge, the third edge, and the fourth edge to another of the first edge, the second edge, the third edge, and the fourth edge; and a minimum value of a proportion of a length of a portion of each of the multiple filaments where the grooves are not formed is 10 percent or more.

11. A water electrolysis device comprising: a current collector; a diaphragm; and an electrode disposed between the current collector and the diaphragm, wherein at least one of the electrode or the current collector is formed from the mesh according to any one of claims 1 to 10.

12. A fuel cell comprising: a current collector; an electrolyte; and an electrode disposed between the current collector and the electrolyte, the current collector being formed from a mesh according to any one of claims 1 to 10.

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