WO2021131689A1 - 多孔体、およびそれを含む燃料電池 - Google Patents
多孔体、およびそれを含む燃料電池 Download PDFInfo
- Publication number
- WO2021131689A1 WO2021131689A1 PCT/JP2020/045774 JP2020045774W WO2021131689A1 WO 2021131689 A1 WO2021131689 A1 WO 2021131689A1 JP 2020045774 W JP2020045774 W JP 2020045774W WO 2021131689 A1 WO2021131689 A1 WO 2021131689A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- skeleton
- porous body
- mass
- cobalt
- less
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/08—Alloys with open or closed pores
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/8605—Porous electrodes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/04—Making non-ferrous alloys by powder metallurgy
- C22C1/0433—Nickel- or cobalt-based alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/07—Alloys based on nickel or cobalt based on cobalt
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D1/00—Electroforming
- C25D1/08—Perforated or foraminous objects, e.g. sieves
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/8647—Inert electrodes with catalytic activity, e.g. for fuel cells consisting of more than one material, e.g. consisting of composites
- H01M4/8652—Inert electrodes with catalytic activity, e.g. for fuel cells consisting of more than one material, e.g. consisting of composites as mixture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/023—Porous and characterised by the material
- H01M8/0232—Metals or alloys
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/023—Porous and characterised by the material
- H01M8/0241—Composites
- H01M8/0245—Composites in the form of layered or coated products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/54—Electroplating of non-metallic surfaces
- C25D5/56—Electroplating of non-metallic surfaces of plastics
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
- H01M2008/1293—Fuel cells with solid oxide electrolytes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- the present disclosure relates to a porous body and a fuel cell containing the same.
- This application claims priority based on Japanese Patent Application No. 2019-232469 filed on December 24, 2019. All the contents of the Japanese patent application are incorporated herein by reference.
- porous materials such as metal porous materials have a high porosity and a large surface area, and therefore have been used in various applications such as battery electrodes, catalyst carriers, metal composite materials, and filters.
- the porous body according to one aspect of the present disclosure is a porous body having a skeleton having a three-dimensional network structure.
- the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements.
- the mass ratio of the cobalt is 0.2 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- the first element is composed of at least one element selected from the group consisting of boron, iron and calcium.
- the second element comprises at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the total ratio of the mass of the first element and the mass of the second element is 5 ppm or more and 50,000 ppm or less with respect to the mass of the main body of the skeleton.
- the fuel cell according to one aspect of the present disclosure is a fuel cell including a current collector for an air electrode and a current collector for a hydrogen electrode, and is at least one of the current collector for the air electrode or the current collector for the hydrogen electrode. Includes the above-mentioned porous body.
- FIG. 1 is a schematic partial cross-sectional view showing an outline of a partial cross section of a skeleton in a porous body according to one aspect of the present disclosure.
- FIG. 2 is a schematic cross-sectional view showing a cross section orthogonal to the longitudinal direction of the skeleton.
- FIG. 3A is an enlarged schematic view focusing on one of the cell portions in the porous body in order to explain the three-dimensional network structure of the porous body according to one aspect of the present disclosure.
- FIG. 3B is a schematic view showing one aspect of the shape of the cell portion.
- FIG. 4A is a schematic view showing another aspect of the shape of the cell portion.
- FIG. 4B is a schematic view showing still another aspect of the shape of the cell portion.
- FIG. 5 is a schematic view showing aspects of the two joined cell portions.
- FIG. 6 is a schematic view showing aspects of the four joined cell portions.
- FIG. 7 is a schematic view showing one aspect of a three-dimensional network structure formed by joining a plurality of cell portions.
- FIG. 8 is a schematic cross-sectional view showing a fuel cell according to one aspect of the present disclosure.
- FIG. 9 is a schematic cross-sectional view showing a fuel cell cell according to one aspect of the present disclosure.
- Patent Document 1 a foamed resin or the like is subjected to a treatment for imparting conductivity, and then the foamed resin is made of a metal.
- Patent Document 1 A method for producing a metal porous body by forming an electroplating layer and, if necessary, incinerating and removing a foamed resin is disclosed.
- Patent Document 2 discloses a metal porous body having a skeleton containing a nickel-tin alloy as a main component as a metal porous body having properties of oxidation resistance and corrosion resistance.
- Patent Document 3 discloses a metal porous body having a skeleton containing a nickel-chromium alloy as a main component as a metal porous body having high corrosion resistance.
- porous bodies such as metal porous bodies are known, and these are used as a current collector for battery electrodes, particularly a current collector for solid oxide fuel cell (SOFC) electrodes (for example,).
- SOFC solid oxide fuel cell
- SOFC solid oxide fuel cell
- an air electrode current collector or a hydrogen electrode current collector there is room for further improvement, such as adjusting the strength of the porous body.
- the present disclosure has been made in view of the above circumstances, and provides a porous body having appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell, and a fuel cell containing the same. With the goal.
- the porous body according to one aspect of the present disclosure is a porous body having a skeleton having a three-dimensional network structure.
- the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements.
- the mass ratio of the cobalt is 0.2 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- the first element is composed of at least one element selected from the group consisting of boron, iron and calcium.
- the second element comprises at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the total ratio of the mass of the first element and the mass of the second element is 5 ppm or more and 50,000 ppm or less with respect to the mass of the main body of the skeleton.
- a porous body having such characteristics can have appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell.
- the mass ratio of the cobalt is preferably 0.2 or more and 0.45 or less or 0.6 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- a porous body having such characteristics can have more appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell.
- the mass ratio of the first element is preferably 4 ppm or more and 40,000 ppm or less with respect to the mass of the main body of the skeleton.
- a porous body having such characteristics can have more appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell.
- the mass ratio of the second element is preferably 1 ppm or more and 10000 ppm or less with respect to the mass of the main body of the skeleton.
- a porous body having such characteristics can have more appropriate strength.
- the main body of the skeleton preferably further contains oxygen as a constituent element.
- This aspect means that the porous body is in a state of being oxidized by use.
- the porous body can maintain high conductivity even in such a state in a high temperature environment.
- the oxygen is preferably contained in the main body of the skeleton in an amount of 0.1% by mass or more and 35% by mass or less. In this case, high conductivity can be maintained more effectively in a high temperature environment.
- the main body of the skeleton preferably contains a spinel-type oxide. In this case as well, high conductivity can be maintained more effectively in a high temperature environment.
- the number of voids having a major axis of 1 ⁇ m or more appearing in an arbitrary 10 ⁇ m square region of the observation image is five. The following is preferable. Thereby, the strength can be sufficiently improved.
- the skeleton is preferably hollow.
- the porous body can be made lightweight, and the required amount of metal can be reduced.
- the porous body preferably has a sheet-like appearance and a thickness of 0.2 mm or more and 2 mm or less.
- the fuel cell according to one aspect of the present disclosure is a fuel cell including a current collector for an air electrode and a current collector for a hydrogen electrode, and is the current collector for the air electrode or the current collector for the hydrogen electrode. At least one of the above contains the porous body.
- a fuel cell having such characteristics can maintain high conductivity in a high temperature environment, and can generate electricity efficiently.
- the present embodiment is not limited to this.
- the notation in the form of "AZ" means the upper and lower limits of the range (that is, A or more and Z or less).
- the unit of A and the unit of Z are the same.
- the porous body according to the present embodiment is a porous body having a skeleton having a three-dimensional network structure.
- the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements.
- the mass ratio of the cobalt is 0.2 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- the first element contains at least one element selected from the group consisting of boron, iron and calcium.
- the second element contains at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the first element preferably comprises at least one element selected from the group consisting of boron, iron and calcium.
- the second element preferably comprises at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the total ratio of the mass of the first element and the mass of the second element is 5 ppm or more and 50,000 ppm or less with respect to the mass of the main body of the skeleton.
- a porous body having such characteristics can have appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell.
- examples of the "porous body" in the present embodiment include a porous body made of a metal, a porous body made of an oxide of the metal, and a porous body containing a metal and an oxide of the metal.
- a porous body in which the mass ratio of cobalt to the total mass of nickel and cobalt in the main body of the skeleton is 0.2 or more has high strength, and even if it is deformed during SOFC stacking, the skeleton tends to be less likely to crack. Further, in a porous body in which the mass ratio of cobalt to the total mass of nickel and cobalt in the main body of the skeleton is 0.8 or less, the fuel cell is manufactured by using the porous body as a current collector for an air electrode or a current collector for a hydrogen electrode. Even so, the solid electrolyte, which is a component of the fuel cell, tends to be hard to break.
- the porous body having the skeleton is a current collector for the air electrode of the fuel cell. And has an appropriate strength as a current collector for hydrogen poles.
- the appearance of the porous body can have various shapes such as a sheet shape, a rectangular parallelepiped shape, a spherical shape, and a columnar shape.
- the porous body preferably has a sheet-like appearance and a thickness of 0.2 mm or more and 2 mm or less.
- the thickness of the porous body is more preferably 0.5 mm or more and 1 mm or less. Since the thickness of the porous body is 2 mm or less, the porous body is thinner than the conventional one, the required metal amount can be reduced, and a compact fuel cell can be manufactured. Since the thickness of the porous body is 0.2 mm or more, the required strength can be provided. The thickness can be measured by, for example, a commercially available digital thickness gauge.
- the porous body has a skeleton having a three-dimensional network structure as described above.
- the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements.
- the mass ratio of the cobalt is 0.2 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- the skeleton 12 includes a main body 11 containing nickel, cobalt, a first element, and a second element as constituent elements (hereinafter, may be referred to as “skeleton main body 11”), and a hollow surrounded by the skeleton main body 11. Consists of 13 inside.
- the skeleton body 11 forms a strut portion and a node portion, which will be described later.
- the skeleton is preferably hollow.
- the skeleton 12 preferably has a triangular cross-sectional shape orthogonal to the longitudinal direction thereof.
- the cross-sectional shape of the skeleton 12 should not be limited to this.
- the cross-sectional shape of the skeleton 12 may be a polygon other than a triangle such as a quadrangle or a hexagon.
- the "triangle" is a concept including not only a geometric triangle but also a substantially triangular shape (for example, a shape in which the apex angle is chamfered, a shape in which R is given to the apex angle, etc.). Is. The same applies to other polygons.
- the cross-sectional shape of the skeleton 12 may be circular.
- the skeleton 12 has a hollow tubular shape inside 13 surrounded by the skeleton body 11, and has a triangular or other polygonal or circular cross section orthogonal to the longitudinal direction. Since the skeleton 12 has a tubular shape, the skeleton main body 11 has an inner wall forming an inner surface of the cylinder and an outer wall forming an outer surface of the cylinder. Since the inside 13 of the skeleton 12 surrounded by the skeleton body 11 is hollow, the porous body can be made very lightweight. However, the skeleton is not limited to being hollow, and may be solid. When the inner portion 13 is solid, the strength of the porous body can be improved.
- the skeleton preferably has a total basis weight of nickel and cobalt of 200 g / m 2 or more and 1000 g / m 2 or less.
- the basis weight is more preferably 250 g / m 2 or more and 900 g / m 2 or less.
- the amount of the texture can be appropriately adjusted when nickel-cobalt alloy plating is performed on the conductive resin molded product which has been subjected to the conductivity treatment for imparting conductivity.
- the above-mentioned total basis weight of nickel and cobalt is converted into the mass per unit volume of the skeleton (apparent density of the skeleton) as follows. That is, the apparent density of the skeleton is preferably 0.14 g / cm 3 or more and 0.75 g / cm 3 or less, and more preferably 0.18 g / cm 3 or more and 0.65 g / cm 3 or less.
- V Volume of appearance shape in skeleton [cm 3 ].
- the porosity of the skeleton is preferably 40% or more and 98% or less, more preferably 45% or more and 98% or less, and most preferably 50% or more and 98% or less.
- the porosity of the skeleton is 40% or more, the porous body can be made very lightweight, and the surface area of the porous body can be increased.
- the porosity of the skeleton is 98% or less, the porous body can be provided with sufficient strength.
- the skeleton preferably has an average pore diameter of 60 ⁇ m or more and 3500 ⁇ m or less.
- the average pore diameter of the skeleton is 60 ⁇ m or more, the strength of the porous body can be increased.
- the average pore diameter of the skeleton is 3500 ⁇ m or less, the bendability (bending workability) of the porous body can be improved. From these viewpoints, the average pore diameter of the skeleton is more preferably 60 ⁇ m or more and 1000 ⁇ m or less, and most preferably 100 ⁇ m or more and 850 ⁇ m or less.
- the porosity and the average pore diameter of the skeleton can be grasped as the porosity and the average pore diameter of the porous body.
- the number of voids having a major axis of 1 ⁇ m or more appearing in an arbitrary 10 ⁇ m square region of the observation image is 5 or less. Is preferable.
- the “major axis” means the longest distance among any two points on the outer edge of the gap in the observation image.
- the number of voids is more preferably 3 or less. Thereby, the strength of the porous body can be sufficiently improved. Further, it is understood that the main body of the skeleton is different from the molded body formed by sintering fine powder because the number of voids is 5 or less.
- the lower limit of the number of voids observed is, for example, zero.
- the "number of voids” means the average number of voids obtained by observing each of a plurality of (for example, 10) "10 ⁇ m square regions" in the cross section of the skeleton body.
- the cross section of the skeleton can be observed by using an electron microscope. Specifically, it is preferable to obtain the above-mentioned "number of voids" by observing the cross section of the skeleton body in 10 visual fields.
- the cross section of the skeleton body may be a cross section orthogonal to the longitudinal direction of the skeleton (for example, FIG. 2) or a cross section parallel to the longitudinal direction of the skeleton (for example, FIG. 1).
- the voids can be distinguished from other parts by the color contrast (difference between light and dark).
- the upper limit of the major axis of the void should not be limited, but is, for example, 10000 ⁇ m.
- the average thickness of the skeleton body is preferably 10 ⁇ m or more and 50 ⁇ m or less.
- the "thickness of the skeleton body” means the shortest distance from the inner wall, which is the interface with the hollow inside the skeleton, to the outer wall outside the skeleton.
- the average value of the "thickness of the skeleton body" obtained at a plurality of locations is defined as the "average thickness of the skeleton body”.
- the thickness of the skeleton body can be determined by observing the cross section of the skeleton with an electron microscope.
- the average thickness of the skeleton body can be obtained by the following method. First, the sheet-shaped porous body is cut so that the cross section of the skeleton body appears. An observation image is obtained by selecting one cut cross section, magnifying it at a magnification of 3000 times, and observing it with an electron microscope. Next, the thickness of any one side of the polygon (for example, the triangle in FIG. 2) forming one skeleton appearing in this observation image is measured at the center of the one side, and this is measured as the skeleton. The thickness of the main body. Further, by performing such a measurement on 10 observation images (10 fields of view), the thickness of the skeleton body at 10 points can be obtained. Finally, by calculating these average values, the average thickness of the skeleton body can be obtained.
- 10 observation images 10 fields of view
- the porous body has a skeleton having a three-dimensional network structure.
- the "three-dimensional network structure” means a three-dimensional network structure.
- the three-dimensional network structure is formed by the skeleton.
- the three-dimensional network structure will be described in detail.
- the three-dimensional network structure 30 has a cell portion 20 as a basic unit, and is formed by joining a plurality of cell portions 20.
- the cell portion 20 includes a support column portion 1 and a node portion 2 that connects a plurality of support column portions 1.
- the terms of the support column 1 and the node section 2 are explained separately for convenience, but there is no clear boundary between them. That is, the plurality of column portions 1 and the plurality of node portions 2 are integrally formed to form the cell portion 20, and the three-dimensional network structure 30 is formed with the cell portion 20 as a constituent unit.
- the cell portion of FIG. 3A will be described as if it were a regular dodecahedron of FIG. 3B.
- the support column portion 1 and the node portion 2 each form a frame portion 10 which is a planar polygonal structure due to the existence of a plurality of each.
- the polygonal structure of the frame portion 10 is a regular pentagon, but it may be a polygon other than a regular pentagon such as a triangle, a quadrangle, or a hexagon.
- a plane polygonal hole is formed by the plurality of support columns 1 and the plurality of node portions 2.
- the hole diameter of the planar polygonal hole means the diameter of a circle circumscribing the planar polygonal hole defined by the frame portion 10.
- the frame portion 10 forms a cell portion 20 which is a three-dimensional polyhedral structure by combining a plurality of the frame portions 10.
- one support column portion 1 and one node portion 2 are shared by a plurality of frame portions 10.
- the strut portion 1 preferably has a hollow tubular shape and has a triangular cross section, but is not limited to this.
- the support column 1 may have a polygonal shape other than a triangle such as a quadrangle or a hexagon, or a circular shape.
- the shape of the node portion 2 may be a shape of a sharp edge having vertices, a planar shape such that the vertices are chamfered, or a radius is given to the vertices. It may have a curved surface shape.
- the polyhedron structure of the cell portion 20 is a dodecahedron in FIG. 3B, but may be another polyhedron such as a cube, an icosahedron (FIG. 4A), or a truncated icosahedron (FIG. 4B).
- a three-dimensional space pore portion 14
- the pore diameter of the three-dimensional space can be grasped as the diameter of a sphere circumscribing the three-dimensional space defined by the cell portion 20.
- the average pore diameter of the porous body in the present embodiment is calculated based on the above-mentioned calculation formula for convenience. That is, the average value of the pore diameters (pore diameters) of the three-dimensional space defined by the cell portion 20 is regarded as the average pore diameter of the skeleton.
- the cell portion 20 forms a three-dimensional network structure 30 by combining a plurality of the cell portions 20 (FIGS. 5 to 7). At this time, the frame portion 10 is shared by the two cell portions 20.
- the three-dimensional network structure 30 can be grasped as including the frame portion 10, or can be grasped as including the cell portion 20.
- the porous body has a three-dimensional network structure that forms a planar polygonal hole (frame portion) and a three-dimensional space (cell portion). Therefore, it can be clearly distinguished from a two-dimensional network structure (for example, punching metal, mesh, etc.) having only planar holes.
- a two-dimensional network structure for example, punching metal, mesh, etc.
- the porous body since a plurality of support columns and a plurality of node portions are integrally formed to form a three-dimensional network structure, the porous body is like a non-woven fabric formed by entwining fibers, which are constituent units, with each other. It can be clearly distinguished from the structure. Since the porous body has such a three-dimensional network structure, it can have continuous ventilation holes.
- the three-dimensional network structure is not limited to the above-mentioned structure.
- the cell portion may be formed by a plurality of frame portions having different sizes and planar shapes.
- the three-dimensional network structure may be formed by a plurality of cell portions having different sizes and three-dimensional shapes.
- the three-dimensional network structure may include a frame portion in which a planar polygonal hole is not formed as a part, or a cell portion in which a three-dimensional space is not formed (a cell portion whose inside is solid). ) May be included in a part.
- the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements as described above. It is not excluded that the body of the skeleton contains components other than nickel, cobalt, the first element and the second element as long as it does not affect the action and effect of the porous body of the present disclosure.
- the main body of the skeleton is preferably composed of the above four components (nickel, cobalt, first element and second element) as metal components.
- the main body of the skeleton preferably contains a nickel-cobalt alloy composed of nickel and cobalt, the first element, and the second element.
- the nickel-cobalt alloy is preferably the main component in the body of the skeleton.
- the "main component" in the main body of the skeleton means the component having the largest mass ratio in the main body of the skeleton. More specifically, it refers to a component having a mass ratio of more than 50% by mass in the main body of the skeleton.
- the total ratio of the mass of nickel and the mass of cobalt in the main body of the skeleton is, for example, the state before using the porous body as the current collector for the air electrode or the current collector for the hydrogen electrode of SOFC, that is, the porous body is 700 ° C. or higher. In the state before being exposed to the high temperature of the above, it is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more with respect to the mass of the main body of the skeleton. ..
- the upper limit of the total ratio of the mass of nickel and the mass of cobalt may be less than 100% by mass, 99% by mass or less, or 95% by mass with respect to the mass of the main body of the skeleton. It may be as follows.
- the proportion of spinel-type oxides consisting of at least one and oxygen tends to increase. As a result, the porous body can maintain high conductivity even when used in a high temperature environment.
- the mass ratio of cobalt is 0.2 or more and 0.8 or less with respect to the total mass of nickel and cobalt.
- Ni 3-x Co x O 4 (however, 0.6 ⁇ ) is generated by oxidation.
- x ⁇ 2.4) typically spinel oxide represented by the chemical formula of NiCo 2 O 4 or Ni 2 CoO 4 is produced in the skeleton.
- Oxidation of the skeleton body may produce spinel-type oxides represented by the chemical formula of CoCo 2 O 4.
- the spinel-type oxide exhibits high conductivity, so that the porous body can maintain high conductivity even when the entire skeleton body is oxidized by use in a high temperature environment.
- the mass ratio of the cobalt is preferably 0.2 or more and 0.45 or less or 0.6 or more and 0.8 or less, and 0.2 or more and 0.45 or less with respect to the total mass of nickel and cobalt. Is more preferable.
- the mass ratio of cobalt to the total mass of nickel and cobalt is 0.6 or more and 0.8 or less, the porous body has higher strength, and even if it is deformed during SOFC stacking, the skeleton The body tends to be more resistant to cracking.
- the porous body is used as an air electrode current collector or a hydrogen electrode current collector. Even when a fuel cell is manufactured, the solid electrolyte, which is a component of the fuel cell, tends to be hard to break.
- the body of the skeleton preferably further contains oxygen as a constituent element. Specifically, oxygen is more preferably contained in the main body of the skeleton in an amount of 0.1% by mass or more and 35% by mass or less. Oxygen in the body of the skeleton can be detected, for example, after using a porous body as a current collector for an air electrode or a current collector for a hydrogen electrode of SOFC. That is, in the state after the porous body is exposed to a high temperature of 700 ° C. or higher, oxygen is preferably contained in the main body of the skeleton in an amount of 0.1% by mass or more and 35% by mass or less. Oxygen is more preferably contained in the main body of the skeleton in an amount of 10% by mass or more and 30% by mass or less, and more preferably 25% by mass or more and 28% by mass or less.
- oxygen is contained as a constituent element in the main body of the skeleton in an amount of 0.1% by mass or more and 35% by mass or less, it is possible to know the thermal history that the porous body was exposed to a high temperature of 700 ° C. or more. Further, when the porous body is used as a current collector for an air electrode or a current collector for a hydrogen electrode of SOFC, it is exposed to a high temperature of 700 ° C. or higher, and a spinel composed of at least one of nickel and cobalt and oxygen in the skeleton. When a type oxide is produced, the main body of the skeleton tends to contain oxygen as a constituent element in an amount of 0.1% by mass or more and 35% by mass or less.
- the main body of the skeleton preferably contains a spinel-type oxide.
- the porous body can more effectively maintain high conductivity even when it is oxidized.
- the mass ratio of oxygen in the main body of the skeleton is out of the above range, the porous body tends not to obtain the performance of more effectively maintaining high conductivity when oxidized, as desired.
- the first element contains at least one element selected from the group consisting of boron, iron and calcium.
- the first element is preferably composed of at least one element selected from the group consisting of boron, iron and calcium.
- the first element is considered to be present at the grain boundaries of crystal grains containing nickel and cobalt. The present inventors consider that the presence of the first element at the grain boundaries of the crystal grains suppresses the coarsening of the crystal grains and thus improves the hardness (strength) of the skeleton body. There is.
- the mass ratio of the first element is preferably 4 ppm or more and 40,000 ppm or less, and more preferably 20 ppm or more and 10,000 ppm or less with respect to the mass of the main body of the skeleton.
- the mass ratio of the first element means the total of the mass ratios of the plurality of types of elements.
- the mass ratio of the first element can be obtained by an EDX device (energy dispersive X-ray analyzer) described later.
- the second element contains at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the second element preferably comprises at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the second element is considered to be present at the grain boundaries of crystal grains containing nickel and cobalt. The present inventors consider that the presence of the second element at the grain boundaries of the crystal grains suppresses the coarsening of the crystal grains and thus improves the hardness (strength) of the skeleton body. There is.
- the second element is contained in the skeleton body together with the first element to prevent the grain boundary diffusion of the first element.
- the first element is contained in the skeleton body together with the second element to prevent the grain boundary diffusion of the second element. That is, it is said that both the first element and the second element are contained in the skeleton body to prevent the intergranular diffusion of both elements and to efficiently suppress the coarsening of the crystal grains.
- the present inventors are thinking.
- the mass ratio of the second element is preferably 1 ppm or more and 10000 ppm or less, and more preferably 1 ppm or more and 5000 ppm or less with respect to the mass of the main body of the skeleton.
- the mass ratio of the second element means the total of the mass ratios of the plurality of types of elements.
- the mass ratio of the second element can be determined by an EDX device described later.
- the first element may be boron, and the second element may be at least one element selected from the group consisting of sodium, aluminum, zinc and tin.
- the first element may be iron, and the second element may be at least one element selected from the group consisting of magnesium, copper, potassium and aluminum.
- the first element may be calcium, and the second element may be at least one element selected from the group consisting of sodium, tin, chromium, titanium and silicon.
- the first element may be boron and calcium, and the second element may be sodium, aluminum and silicon.
- the first element may be boron and iron, and the second element may be magnesium and tin.
- the first element may be boron, iron and calcium, and the second element may be sodium, aluminum, silicon and tin.
- the total ratio of the mass of the first element and the mass of the second element is 5 ppm or more and 50,000 ppm or less, preferably 10 ppm or more and 10000 ppm or less, and 55 ppm or more and 477 ppm or less with respect to the mass of the main body of the skeleton. Is more preferable.
- the mass of the first element means the total mass of these plurality of types of elements. The same applies to the case of the second element.
- the main body of the skeleton can contain other components as constituent elements as described above as long as it does not affect the action and effect of the porous body of the present disclosure.
- the skeleton may contain, for example, carbon, tungsten, phosphorus, silver, gold, molybdenum, nitrogen, sulfur, fluorine, chlorine and the like as other components.
- the main body of the skeleton may contain the above-mentioned oxygen as another component in a state before using the porous body as a current collector for an air electrode or a current collector for a hydrogen electrode of SOFC.
- the other components in the skeleton body are preferably 5% by mass or less by themselves, and preferably 10% by mass or less in total.
- the main body of the skeleton may further contain at least one non-metal element selected from the group consisting of nitrogen, sulfur, fluorine, and chlorine as a constituent element.
- the total mass ratio of the non-metal element may be 5 ppm or more and 10000 ppm or less with respect to the mass of the main body of the skeleton.
- the total mass ratio of the non-metal element is 10 ppm or more and 8000 ppm or less with respect to the mass of the main body of the skeleton.
- the main body of the skeleton may further contain phosphorus as a constituent element.
- the mass ratio of phosphorus may be 5 ppm or more and 50,000 ppm or less with respect to the mass of the main body of the skeleton.
- the mass ratio of phosphorus is 10 ppm or more and 40,000 ppm or less with respect to the mass of the main body of the skeleton.
- the main body of the skeleton may further contain at least two non-metal elements selected from the group consisting of nitrogen, sulfur, fluorine, chlorine, and phosphorus as constituent elements.
- the total mass ratio of the non-metal element may be 5 ppm or more and 50,000 ppm or less with respect to the mass of the main body of the skeleton.
- the total mass ratio of the non-metal element is 10 ppm or more and 10000 ppm or less with respect to the mass of the main body of the skeleton.
- the porous body When the porous body is used as a current collector for an air electrode or a current collector for a hydrogen electrode of a fuel cell, it is exposed to a high temperature environment of 700 ° C. or higher as described above, but the main body of the skeleton is the non-metal described above. By containing the element as a constituent element, an appropriate strength can be maintained.
- the EDX device for example, SEM
- the observation image electron microscope image
- Part Product name "SUPRA35VP”, manufactured by Carl Zeiss Microscopy Co., Ltd.
- EDX Part Product name "octane super”, manufactured by Ametec Co., Ltd.). It is also possible to determine the mass ratio of nickel, cobalt, the first element and the second element in the main body of the skeleton by the above EDX device.
- the mass%, mass ratio, etc. of nickel, cobalt, the first element and the second element in the main body of the skeleton can be obtained.
- the mass% of oxygen in the main body of the skeleton can be obtained by the same method.
- X-ray diffraction is performed by irradiating the cross section with X-rays and analyzing the diffraction pattern. It can be specified by using the (XRD) method.
- an X-ray diffractometer for example, trade name (model number): "Empyrene", manufactured by Spectris Co., Ltd.
- X-ray analysis software PDXL X-ray analysis software
- the fuel cell according to the present embodiment is a fuel cell including a current collector for an air electrode and a current collector for a hydrogen electrode. At least one of the current collector for the air electrode and the current collector for the hydrogen electrode contains the porous body.
- the current collector for the air electrode or the current collector for the hydrogen electrode includes a porous body having an appropriate strength as a current collector for a fuel cell as described above. Therefore, the above-mentioned current collector for air electrode or current collector for hydrogen electrode is suitable as at least one of the current collector for air electrode or current collector for hydrogen electrode of SOFC.
- the porous body contains nickel, cobalt, a first element and a second element, it is more preferable to use the porous body as a current collector for an air electrode.
- FIG. 8 is a schematic cross-sectional view showing a fuel cell according to one aspect of the present disclosure.
- the fuel cell 150 includes a current collector 110 for a hydrogen electrode, a current collector 120 for an air electrode, and a cell 100 for a fuel cell.
- the fuel cell cell 100 is provided between the hydrogen electrode current collector 110 and the air electrode current collector 120.
- the "current collector for hydrogen electrode” means a current collector on the side of supplying hydrogen in the fuel cell.
- the “air electrode current collector” means a current collector on the side of supplying a gas containing oxygen (for example, air) in a fuel cell.
- FIG. 9 is a schematic cross-sectional view showing a fuel cell cell according to one aspect of the present disclosure.
- the fuel cell cell 100 includes an air electrode 102, a hydrogen electrode 108, an electrolyte layer 106 provided between the air electrode 102 and the hydrogen electrode 108, and the electrolyte layer 106 and the air electrode 102.
- An intermediate layer 104 provided between them is provided in order to prevent the reaction of the above.
- the air electrode for example, an oxide of LaSrCo (LSC) is used.
- LSC LaSrCo
- the electrolyte layer for example, a Y-doped Zr oxide (YSZ) is used.
- YSZ Y-doped Zr oxide
- GDC Gd-doped Ce oxide
- As the hydrogen electrode for example, a mixture of YSZ and NiO 2 is used.
- the fuel cell 150 further includes a first interconnector 112 having a fuel flow path 114 and a second interconnector 122 having an oxidant flow path 124.
- the fuel flow path 114 is a flow path for supplying fuel (for example, hydrogen) to the hydrogen electrode 108.
- the fuel flow path 114 is provided on the main surface of the first interconnector 112, which faces the current collector 110 for hydrogen poles.
- the oxidant flow path 124 is a flow path for supplying an oxidant (for example, oxygen) to the air electrode 102.
- the oxidant flow path 124 is provided on the main surface of the second interconnector 122 facing the air electrode current collector 120.
- the porous body according to the present embodiment can be produced by appropriately using a conventionally known method. Therefore, the method for producing the porous body should not be particularly limited, but the following method is preferable.
- a step of obtaining a conductive resin molded body by forming a conductive coating layer on a resin molded body having a three-dimensional network structure (first step), and nickel-cobalt alloy plating on the conductive resin molded body.
- a step of obtaining a porous body precursor (second step) and a heat treatment of the porous body precursor are performed to incinerate the resin component in the conductive resin molded product, and the resin component is removed to make the porous body precursor porous. It is preferable to produce a porous body by a method for producing a porous body including a step of obtaining a body (third step).
- nickel-cobalt alloy is an alloy containing nickel and cobalt as main components and may contain other elements (for example, nickel and cobalt as main components and the above-mentioned first item. (Alloy containing one element and the above second element).
- a sheet of a resin molded body having a three-dimensional network structure (hereinafter, also simply referred to as “resin molded body”) is prepared.
- a polyurethane resin, a melamine resin, or the like can be used as the resin molded product.
- a conductive treatment for imparting conductivity to the resin molded body a conductive coating layer is formed on the surface of the resin molded body. Examples of the conductive treatment include the following methods. (1) Applying a conductive paint containing conductive particles such as carbon and conductive ceramic and a binder to the surface of the resin molded product by means such as coating and impregnation.
- a nickel-cobalt alloy plating is performed on the conductive resin molded product to obtain a porous precursor.
- electroless plating can be applied, but from the viewpoint of efficiency, electrolytic plating (so-called electroplating of alloy) is preferably used.
- electrolytic plating sin-called electroplating of alloy
- a conductive resin molded product is used as a cathode.
- the plating bath used for electrolytic plating of the nickel-cobalt alloy a known one can be used.
- a watt bath, a chloride bath, a sulfamic acid bath and the like can be used.
- bath composition of the electrolytic plating of the nickel-cobalt alloy include the following examples.
- the salt containing the first element described above as an element include FeSO 4 ⁇ 7H 2 O and CaSO 4 ⁇ 2H 2 O.
- Salts containing a second of the above-mentioned elements as an element include 2 and ZnSO 4 ⁇ 7H 2 O.
- Examples of the electrolytic conditions for electrolytic plating of a nickel-cobalt alloy include the following. (Electrolysis conditions) Temperature: 40-60 ° C Current density: 0.5-10A / dm 2 Anode: Insoluble anode.
- a porous precursor in which a nickel-cobalt alloy is plated on a conductive resin molded body.
- non-metal elements such as nitrogen, sulfur, fluorine, chlorine, and phosphorus are added, they can be contained in the porous precursor by adding various additives into the plating bath.
- additives include, but are not limited to, sodium nitrate, sodium sulfate, sodium fluoride, sodium chloride, and sodium phosphate, as long as each non-metal element is contained.
- the porous body precursor is heat-treated to incinerate the resin component in the conductive resin molded product, and the porous body is removed to obtain a porous body.
- the temperature and atmosphere of the heat treatment for removing the resin component may be, for example, 600 ° C. or higher, and may be an oxidizing atmosphere such as the atmosphere.
- the average pore diameter of the porous body obtained by the above method is substantially equal to the average pore diameter of the resin molded product. Therefore, the average pore diameter of the resin molded product used to obtain the porous body may be appropriately selected according to the application to which the porous body is applied. Since the porosity of the porous body is finally determined by the amount of metal to be plated (graining amount), the porosity of the nickel-cobalt alloy to be plated is determined according to the porosity required for the porous body, which is the final product. It may be selected as appropriate.
- the porosity and average pore diameter of the resin molded product are defined in the same manner as the porosity and average pore diameter of the skeleton described above, and the above calculation formula is applied by replacing "skeleton” with “resin molded product”. Can be obtained based on.
- the porous body has a skeleton having a three-dimensional network structure, and the main body of the skeleton contains nickel, cobalt, a first element and a second element as constituent elements. Further, the mass ratio of cobalt is 0.2 or more and 0.8 or less with respect to the total mass of nickel and cobalt.
- the first element contains at least one element selected from the group consisting of boron, iron and calcium, and the second element is sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- the porous body can have an appropriate strength as a current collector for an air electrode or a current collector for a hydrogen electrode of a fuel cell.
- a porous body having a skeleton having a three-dimensional network structure contains nickel, cobalt, a first element and a second element as constituent elements.
- the mass ratio of the cobalt is 0.2 or more and 0.8 or less with respect to the total mass of the nickel and the cobalt.
- the first element contains at least one element selected from the group consisting of boron, iron and calcium.
- the second element contains at least one element selected from the group consisting of sodium, magnesium, aluminum, silicon, potassium, titanium, chromium, copper, zinc and tin.
- Appendix 2 The porous body according to Appendix 1, wherein the mass ratio of the cobalt is 0.2 or more and 0.45 or less with respect to the total mass of the nickel and the cobalt.
- Appendix 3 The porous body according to Appendix 1, wherein the total ratio of the mass of the first element and the mass of the second element is 55 ppm or more and 477 ppm or less with respect to the mass of the main body of the skeleton.
- (Appendix 4) The porous body according to Appendix 1, wherein the total mass ratio of the nickel and the cobalt in the main body of the skeleton is 80% by mass or more and less than 100% by mass.
- (Appendix 5) The porous body according to Appendix 1, wherein the first element is boron, and the second element is at least one element selected from the group consisting of sodium, aluminum, zinc and tin.
- (Appendix 6) The porous body according to Appendix 1, wherein the first element is iron, and the second element is at least one element selected from the group consisting of magnesium, copper, potassium and aluminum.
- Porous bodies of Samples 1 to 12 were prepared by the following procedure. (First step) First, a 1.5 mm thick polyurethane resin sheet was prepared as a resin molded body having a three-dimensional network structure. When the porosity and the average porosity of the polyurethane resin sheet were calculated based on the above formula, the porosity was 96% and the average porosity was 450 ⁇ m.
- the resin molded body was impregnated with a conductive paint (slurry containing carbon black), then squeezed with a roll and dried to form a conductive coating layer on the surface of the resin molded body. As a result, a conductive resin molded product was obtained.
- a conductive paint slurry containing carbon black
- Electroplating was performed using the conductive resin molded product as a cathode under the following bath composition and electrolytic conditions. As a result, a nickel-cobalt alloy was adhered to the conductive resin molded body at 660 g / m 2 to obtain a porous precursor.
- the calcium as the first element, to be included in the porous body in a mass ratio shown in Table 2 it was added CaSO 4 ⁇ 2H 2 O in the plating bath, and, as a secondary element Na 2 SO 4 , SnSO 4 , Cr 2 (SO 4 ) 3 ⁇ nH 2 O or Ti (SO 4 ) so that sodium, tin, chromium or titanium is contained in the porous body in the mass ratio shown in Table 2.
- 2 was added to the plating bath in the same manner as in ⁇ Sample 1 to Sample 12> to prepare porous bodies of Samples 25 to 36.
- ⁇ Sample 37-Sample 39> In a second step, the calcium as the first element, to be included in the porous body in a mass ratio shown in Table 2, it was added CaSO 4 ⁇ 2H 2 O in the plating bath, and, as a secondary element By making it the same as ⁇ Sample 1 to Sample 12> except that Na 2 SiO 3 was added to the plating bath so that silicon and sodium were contained in the porous body in the mass ratios shown in Table 2. Porous bodies of Samples 37 to 39 were prepared.
- ⁇ Sample 40-Sample 42> In the second step, boron and calcium as the first element, to be included in the porous body in a mass ratio shown in Table 3, Na 2 B 4 O 5 (OH) 4 ⁇ 8H 2 O and CaSO 4 ⁇ 2H Al 2 (SO 4 ) 3 and Na so that 2 O was added to the plating bath and aluminum, silicon and sodium as the second elements were contained in the porous body in the mass ratios shown in Table 3.
- ⁇ Sample 1 to Sample 12> By making the same as ⁇ Sample 1 to Sample 12> except that 2 SiO 3 was added to the plating bath, porous bodies of Sample 40 to Sample 42 were prepared.
- ⁇ Sample 43-Sample 45> In the second step, boron and iron as a first element, to be included in the porous body in a mass ratio shown in Table 3, Na 2 B 4 O 5 (OH) 4 ⁇ 8H 2 O and FeSO 4 ⁇ 7H 2 O was added to the plating bath, and magnesium 4 and SnSO 4 were added to the plating bath so that magnesium and iron as the second elements were contained in the porous body in the mass ratios shown in Table 3.
- porous bodies of Sample 43 to Sample 45 were prepared.
- ⁇ Sample 46-Sample 48> In the second step, boron as a first element, iron and calcium, as contained in the porous body in a mass ratio shown in Table 3, Na 2 B 4 O 5 (OH) 4 ⁇ 8H 2 O, FeSO 4 ⁇ 7H 2 O and CaSO 4 ⁇ 2H 2 O that was added to the plating bath, as well as aluminum as a second element, silicon, tin and sodium, as contained in the porous body in a mass ratio shown in Table 3
- Al 2 (SO 4 ) 3 , Na 2 SiO 3 and SnSO 4 were added to the plating bath, the porous bodies of Samples 46 to 48 were made. Made.
- ⁇ Sample 101-Sample 103> By making the same as ⁇ Sample 1 to Sample 12> except that the salts corresponding to the first element and the second element were not added to the plating bath in the second step (Sample 1 to Sample 12), Sample 101 to Sample 103 porous bodies were prepared. In Table 4 and Table 5 described later, the parts indicated by “-" in the columns of "first element” and “second element” indicate that the corresponding element is not contained in the porous body. means.
- ⁇ Sample 104-Sample 112> In the second step, the salt corresponding to the first element was not added to the plating bath, and tin, sodium or chromium as the second element was contained in the porous body in the mass ratio shown in Table 4. As described above, by making the same as ⁇ Sample 1 to Sample 12> except that SnSO 4 , Na 2 SO 4 or Cr 2 (SO 4 ) 3 ⁇ nH 2 O was added to the plating bath, Sample 104 to Sample 112 porous bodies were prepared.
- porous bodies of Samples 113 to 121 were prepared.
- ⁇ Sample 122-Sample 130> In the second step, boron as a first element, iron or calcium, to be included in the porous body in a mass ratio shown in Table 5, Na 2 B 4 O 5 (OH) 4 ⁇ 8H 2 O, FeSO 4 ⁇ 7H 2 O or CaSO 4 ⁇ 2H 2 O that was added to the plating bath, and, aluminum, to be included in the porous body in a mass ratio shown in Table 5 as a secondary element, Al 2 (sO 4 )
- Table 5 As a secondary element, Al 2 (sO 4 )
- the cross section of the skeleton of the cut porous body was observed by the above EDX device, and the mass ratio of the cobalt was determined based on the atomic concentration of each detected element.
- the mass ratio of cobalt to the total mass of nickel and cobalt in the skeleton body of the porous bodies of Samples 1 to 48 and the porous bodies of Samples 101 to 130 was found in the plating bath used for producing them. It was consistent with the mass ratio of cobalt (the mass ratio of Co / (Ni + Co)) to the total mass of nickel and cobalt contained.
- the average pore diameter and porosity of the skeleton were determined according to the above-mentioned calculation formula. As a result, it was consistent with the porosity and the average pore diameter of the resin molded product, the porosity was 96%, and the average pore diameter was 450 ⁇ m. Further, the porous bodies of Samples 1 to 48 and the porous bodies of Samples 101 to 130 had a thickness of 1.4 mm. The total basis weight of nickel and cobalt in the porous bodies of Samples 1 to 48 and the porous bodies of Samples 101 to 130 was 660 g / m 2 as described above.
- the main body of the skeleton contains nickel, cobalt, the first element and the second element, and the total of the mass ratio of the first element and the mass ratio of the second element is the above. It was found that when the amount was 5 ppm or more and 50,000 ppm or less with respect to the main body of the skeleton, no crack was observed in the solid electrolyte contained in the fuel cell. Further, it was found that the fuel cell was good because the operating voltage retention rate after 2000 hours after power generation exceeded 90%.
- the porous body according to the example has appropriate strength as a current collector for an air electrode and a current collector for a hydrogen electrode of a fuel cell.
- the main body of the skeleton contains nickel, cobalt, the first element and the second element, and the total of the mass ratio of the first element and the mass ratio of the second element is the skeleton.
- the amount exceeds 50,000 ppm with respect to the main body of the fuel cell, cracks were observed in the solid electrolyte contained in the fuel cell (Samples 122 to 130).
- the operating voltage retention rate 2000 hours after the power generation could not be measured because the solid electrolyte had cracks.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Mechanical Engineering (AREA)
- Composite Materials (AREA)
- Inert Electrodes (AREA)
- Fuel Cell (AREA)
Abstract
Description
上記骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含み、
上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して、0.2以上0.8以下であり、
上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素からなり、
上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素からなり、
上記第一元素の質量と上記第二元素の質量との合計の割合は、上記骨格の本体の質量に対して5ppm以上50000ppm以下である。
このような金属多孔体の製造方法としては、たとえば特開平11-154517号公報(特許文献1)において、発泡樹脂などに導電性を付与する処理を施した後、この発泡樹脂上に金属からなる電気めっき層を形成し、必要に応じて発泡樹脂を焼却し、除去することによって金属多孔体を製造する方法が開示されている。
上記によれば、燃料電池の空気極用集電体および水素極用集電体として適度な強度を有する多孔体、およびそれを含む燃料電池を提供することができる。
最初に本開示の実施態様を列記して説明する。
[1]本開示の一態様に係る多孔体は、三次元網目状構造を有する骨格を備えた多孔体であって、
上記骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含み、
上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して、0.2以上0.8以下であり、
上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素からなり、
上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素からなり、
上記第一元素の質量と上記第二元素の質量との合計の割合は、上記骨格の本体の質量に対して5ppm以上50000ppm以下である。このような特徴を有する多孔体は、燃料電池の空気極用集電体および水素極用集電体として適度な強度を有することができる。
以下、本開示の一実施形態(以下、「本実施形態」とも記す。)について説明する。ただし、本実施形態はこれに限定されるものではない。本明細書において「A~Z」という形式の表記は、範囲の上限下限(すなわちA以上Z以下)を意味する。Aにおいて単位の記載がなく、Zにおいてのみ単位が記載されている場合、Aの単位とZの単位とは同じである。
本実施形態に係る多孔体は、三次元網目状構造を有する骨格を備えた多孔体である。上記骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含む。上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して0.2以上0.8以下である。上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素を含む。上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素を含む。本実施形態の一側面において、上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素からなることが好ましい。上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素からなることが好ましい。上記第一元素の質量と上記第二元素の質量との合計の割合は、上記骨格の本体の質量に対して5ppm以上50000ppm以下である。このような特徴を有する多孔体は、燃料電池の空気極用集電体および水素極用集電体として適度な強度を有することができる。ここで、本実施形態における「多孔体」としては、たとえば、金属からなる多孔体、当該金属の酸化物からなる多孔体、金属および当該金属の酸化物を含む多孔体が挙げられる。
多孔体は、上述のとおり三次元網目状構造を有する骨格を備える。骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含む。上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して0.2以上0.8以下である。
骨格の見かけの密度(g/cm3)=M(g)/V(cm3)
M:骨格の質量[g]
V:骨格における外観の形状の体積[cm3]。
気孔率(%)=[1-{M/(V×d)}]×100
M:骨格の質量[g]
V:骨格における外観の形状の体積[cm3]
d:骨格を構成する物質自体の密度[g/cm3]。
平均気孔径(μm)=25400μm/nc。
多孔体は、三次元網目状構造を有する骨格を備える。本実施形態において「三次元網目状構造」とは、立体的な網目状の構造を意味する。三次元網目状構造は、骨格によって形成される。以下、三次元網目状構造について詳細に説明する。
骨格の本体は、上述のとおりニッケルとコバルトと第一元素と第二元素とを構成元素として含む。骨格の本体は、本開示の多孔体が有する作用効果に影響を与えない限り、ニッケル、コバルト、第一元素及び第二元素以外の他の成分を含むことを除外するものではない。本実施形態の一側面において、骨格の本体は、金属成分として上記の4成分(ニッケル、コバルト、第一元素および第二元素)からなることが好ましい。具体的には、骨格の本体は、ニッケルおよびコバルトからなるニッケル-コバルト合金と上記第一元素と上記第二元素とを含むことが好ましい。ニッケル-コバルト合金は、骨格の本体における主成分であることが好ましい。ここで骨格の本体における「主成分」とは、骨格の本体において占める質量割合が最も多い成分をいう。より具体的には、骨格の本体における質量割合が50質量%を超える成分をいう。
コバルトの質量割合は、ニッケルおよびコバルトの合計質量に対して、0.2以上0.8以下である。このような組成を有する骨格を備える多孔体をSOFCの空気極用集電体または水素極用集電体などに用いた場合、酸化によってNi3-xCoxO4(ただし、0.6≦x≦2.4)、典型的にはNiCo2O4またはNi2CoO4の化学式で示されるスピネル型酸化物が骨格中に生成される。骨格本体の酸化によりCoCo2O4の化学式で示されるスピネル型酸化物が生成される場合もある。スピネル型酸化物は、高い導電性を示し、もって多孔体は、高温環境下での使用によって骨格本体の全体が酸化された場合にも高い導電性を維持することができる。
骨格の本体は、酸素を構成元素としてさらに含むことが好ましい。具体的には、酸素は、上記骨格の本体において0.1質量%以上35質量%以下含まれることがより好ましい。骨格本体中の酸素は、たとえば多孔体をSOFCの空気極用集電体または水素極用集電体として用いた後に検出され得る。すなわち多孔体を700℃以上の高温に曝した後の状態で、酸素は、上記骨格の本体において0.1質量%以上35質量%以下含まれることが好ましい。酸素は、上記骨格の本体において10質量%以上30質量%以下含まれることがより好ましく、25質量%以上28質量%以下含まれることがさらに好ましい。
上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素を含む。上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素からなることが好ましい。上記第一元素は、ニッケルとコバルトとを含む結晶粒の粒界に存在していると考えられる。上記第一元素が上記結晶粒の粒界に存在していることで、当該結晶粒の粗大化が抑制され、ひいては骨格本体の硬度(強度)が向上していると本発明者らは考えている。
上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素を含む。上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素からなることが好ましい。上記第二元素は、ニッケルとコバルトとを含む結晶粒の粒界に存在していると考えられる。上記第二元素が上記結晶粒の粒界に存在していることで、当該結晶粒の粗大化が抑制され、ひいては骨格本体の硬度(強度)が向上していると本発明者らは考えている。
骨格の本体は、本開示の多孔体が有する作用効果に影響を与えない限り、上述のように他の成分を構成元素として含むことができる。骨格は、他の成分としてたとえば炭素、タングステン、リン、銀、金、モリブデン、窒素、硫黄、フッ素、及び塩素などが含まれていてもよい。さらに骨格の本体は、他の成分として上述の酸素が、多孔体をSOFCの空気極用集電体または水素極用集電体として用いる前の状態において含まれていてもよい。骨格本体中において他の成分は、これら単独で5質量%以下であることが好ましく、これらの合計で10質量%以下であることが好ましい。
骨格の本体における各元素(例えば酸素)の質量割合(質量%)については、切断された骨格の断面の観察像(電子顕微鏡像)に対し、電子顕微鏡(SEM)に付帯のEDX装置(たとえばSEM部分:商品名「SUPRA35VP」、カールツァイスマイクロスコピー株式会社製、EDX部分:商品名「octane super」、アメテック株式会社製)を用いて分析することにより求めることができる。上記EDX装置により、骨格の本体におけるニッケル、コバルト、第一元素及び第二元素の質量割合を求めることも可能である。具体的には、上記EDX装置により検出された各元素の原子濃度に基づいて、骨格の本体におけるニッケル、コバルト、第一元素及び第二元素の質量%、質量比などをそれぞれ求めることができる。骨格の本体に酸素が含まれる場合には、骨格の本体における酸素の質量%も同様の方法で求めることができる。さらに、上記骨格の本体がニッケルおよびコバルトの少なくとも一方、ならびに酸素からなるスピネル型酸化物を有するか否かについては、上記断面に対してX線を照射し、その回折パターンを解析するX線回折(XRD)法を用いることによって特定することができる。
X線回折法: θ-2θ法
測定系: 平行ビーム光学系ミラー
スキャン範囲(2θ): 10~90°
積算時間: 1秒/ステップ
ステップ: 0.03°。
本実施形態に係る燃料電池は、空気極用集電体および水素極用集電体を備える燃料電池である。上記空気極用集電体または上記水素極用集電体の少なくとも一方は、上記の多孔体を含む。上記空気極用集電体または水素極用集電体は、上述のように燃料電池用の集電体として適度な強度を有する多孔体を含む。そのため上記空気極用集電体または水素極用集電体は、SOFCの空気極用集電体または水素極用集電体の少なくとも一方として好適である。上記燃料電池は、多孔体がニッケルとコバルトと第一元素と第二元素とを含むため、上記多孔体を空気極用集電体として用いることがより好適である。
本実施形態に係る多孔体は、従来公知の手法を適宜用いることにより製造することができる。このため上記多孔体の製造方法は、特に制限されるべきではないが、次の方法とすることが好ましい。
まず、三次元網目状構造を有する樹脂成形体(以下、単に「樹脂成形体」とも記す。)のシートを準備する。樹脂成形体としてポリウレタン樹脂、メラミン樹脂などを用いることができる。さらに、樹脂成形体に導電性を付与する導電化処理として、樹脂成形体の表面に導電被覆層を形成する。この導電化処理としては、たとえば以下の方法を挙げることができる。
(1)カーボン、導電性セラミックなどの導電性粒子およびバインダーを含有した導電性塗料を塗布、含浸などの手段により樹脂成形体の表面に含ませること、
(2)無電解めっき法によってニッケルおよび銅などの導電性金属による層を樹脂成形体の表面に形成すること、
(3)蒸着法またはスパッタリング法によって導電性金属による層を樹脂成形体の表面に形成すること。これにより、導電性樹脂成形体を得ることができる。
次に、上記導電性樹脂成形体上にニッケル-コバルト合金めっきを行なうことにより多孔体前駆体を得る。ニッケル-コバルト合金めっきの方法は、無電解めっきを適用することもできるが、効率の観点から電解めっき(所謂、合金の電気めっき)を用いることが好ましい。ニッケル-コバルト合金の電解めっきでは、導電性樹脂成形体をカソードとして用いる。
塩(水溶液): スルファミン酸ニッケルおよびスルファミン酸コバルト(NiおよびCoの合計量として350~450g/L)
ただし、Ni及びCoそれぞれの質量比については、所望するNiおよびCoの合計質量に対するCoの質量割合により、Co/(Ni+Co)=0.2~0.8から調整する。
第一元素を構成元素として含む塩
第二元素を構成元素として含む塩
ホウ酸: 30~40g/L
pH: 4~4.5。
(電解条件)
温度: 40~60℃
電流密度: 0.5~10A/dm2
アノード: 不溶性陽極。
続いて、上記多孔体前駆体に対して熱処理を行なって、導電性樹脂成形体中の樹脂成分を焼却し、これを除去することにより多孔体を得る。これにより、三次元網目状構造を有する骨格を備えた多孔体を得ることができる。上記樹脂成分を除去するための熱処理の温度および雰囲気は、たとえば600℃以上とし、大気などの酸化性雰囲気とすればよい。
(付記1)
三次元網目状構造を有する骨格を備えた多孔体であって、
上記骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含み、
上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して、0.2以上0.8以下であり、
上記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素を含み、
上記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素を含み、
上記第一元素の質量と上記第二元素の質量との合計の割合は、上記骨格の本体の質量に対して5ppm以上50000ppm以下である、多孔体。
(付記2)
上記コバルトの質量割合は、上記ニッケルおよび上記コバルトの合計質量に対して、0.2以上0.45以下である、付記1に記載の多孔体。
(付記3)
上記第一元素の質量と上記第二元素の質量との合計の割合は、上記骨格の本体の質量に対して55ppm以上477ppm以下である、付記1に記載の多孔体。
(付記4)
上記骨格の本体における上記ニッケルおよび上記コバルトの合計の質量割合は、80質量%以上100質量%未満である、付記1に記載の多孔体。
(付記5)
上記第一元素はホウ素であり、かつ上記第二元素はナトリウム、アルミニウム、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素である、付記1に記載の多孔体。
(付記6)
上記第一元素は鉄であり、かつ上記第二元素はマグネシウム、銅、カリウム及びアルミニウムからなる群より選ばれる少なくとも1種の元素である、付記1に記載の多孔体。
(付記7)
上記第一元素はカルシウムであり、かつ上記第二元素はナトリウム、スズ、クロム、チタン及びケイ素からなる群より選ばれる少なくとも1種の元素である、付記1に記載の多孔体。
(付記8)
上記第一元素はホウ素及びカルシウムであり、かつ上記第二元素はナトリウム、アルミニウム及びケイ素である、付記1に記載の多孔体。
(付記9)
上記第一元素はホウ素及び鉄であり、かつ上記第二元素はマグネシウム及びスズである、付記1に記載の多孔体。
(付記10)
上記第一元素はホウ素、鉄及びカルシウムであり、かつ上記第二元素はナトリウム、アルミニウム、ケイ素及びスズである、付記1に記載の多孔体。
<試料1~試料12>
以下の手順で試料1~試料12の多孔体を作製した。
(第1工程)
まず三次元網目状構造を有する樹脂成形体として1.5mm厚のポリウレタン樹脂製シートを準備した。このポリウレタン樹脂製シートの気孔率および平均気孔径を上述の計算式に基づいて求めたところ、上記気孔率は96%であり、上記平均気孔径は450μmであった。
上記導電性樹脂成形体をカソードとし、下記の浴組成および電解条件の下で電解めっきを行なった。これにより、導電性樹脂成形体上にニッケル-コバルト合金を660g/m2付着させ、もって多孔体前駆体を得た。
塩(水溶液):スルファミン酸ニッケル及びスルファミン酸コバルトの水溶液 NiおよびCoの合計量を400g/Lとした。
Co/(Ni+Co)の質量割合を0.22、0.58又は0.78とした。
第一元素としてホウ素を、表1に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2Oをめっき浴中に添加した。
第二元素としてナトリウム、アルミニウム、亜鉛又はスズを、表1に記載の質量割合で多孔体中に含まれるように、Na2SO4、Al2(SO4)3、ZnSO4・7H2O又はSnSO4をめっき浴中に添加した。
ホウ酸: 35g/L
pH: 4.5。
温度: 50℃
電流密度: 5A/dm2
アノード: 不溶性陽極。
上記多孔体前駆体に対して熱処理を行なって、導電性樹脂成形体中の樹脂成分を焼却し、これを除去することにより試料1~試料12の多孔体を得た。このとき、上記樹脂成分を除去するための熱処理の温度は650℃であり、熱処理中の雰囲気は大気雰囲気であった。
第2工程において、第一元素として鉄を、表1に記載の質量割合で多孔体中に含まれるように、FeSO4・7H2Oをめっき浴中に添加したこと、及び、第二元素としてマグネシウム、銅、カリウム又はアルミニウムを、表1に記載の質量割合で多孔体中に含まれるように、MgSO4、CuSO4・5H2O、K2SO4又はAl2(SO4)3をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料13~試料24の多孔体を作製した。
第2工程において、第一元素としてカルシウムを、表2に記載の質量割合で多孔体中に含まれるように、CaSO4・2H2Oをめっき浴中に添加したこと、及び、第二元素としてナトリウム、スズ、クロム又はチタンを、表2に記載の質量割合で多孔体中に含まれるように、Na2SO4、SnSO4、Cr2(SO4)3・nH2O又はTi(SO4)2をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料25~試料36の多孔体を作製した。
第2工程において、第一元素としてカルシウムを、表2に記載の質量割合で多孔体中に含まれるように、CaSO4・2H2Oをめっき浴中に添加したこと、及び、第二元素としてケイ素及びナトリウムを、表2に記載の質量割合で多孔体中に含まれるように、Na2SiO3をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料37~試料39の多孔体を作製した。
第2工程において、第一元素としてホウ素及びカルシウムを、表3に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2O及びCaSO4・2H2Oをめっき浴中に添加したこと、並びに、第二元素としてアルミニウム、ケイ素及びナトリウムを、表3に記載の質量割合で多孔体中に含まれるように、Al2(SO4)3及びNa2SiO3をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料40~試料42の多孔体を作製した。
第2工程において、第一元素としてホウ素及び鉄を、表3に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2O及びFeSO4・7H2Oをめっき浴中に添加したこと、並びに、第二元素としてマグネシウム及びスズを、表3に記載の質量割合で多孔体中に含まれるように、MgSO4及びSnSO4をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料43~試料45の多孔体を作製した。
第2工程において、第一元素としてホウ素、鉄及びカルシウムを、表3に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2O、FeSO4・7H2O及びCaSO4・2H2Oをめっき浴中に添加したこと、並びに、第二元素としてアルミニウム、ケイ素、スズ及びナトリウムを、表3に記載の質量割合で多孔体中に含まれるように、Al2(SO4)3、Na2SiO3及びSnSO4をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料46~試料48の多孔体を作製した。
第2工程において、第一元素及び第二元素に対応する塩をめっき浴中に添加しなかったこと(表4)以外は<試料1~試料12>と同じにすることで、試料101~試料103の多孔体を作製した。なお、表4及び後述する表5中、「第一元素」及び「第二元素」の欄において「-」で示されている箇所は、対応する元素が多孔体中に含まれていないことを意味する。
第2工程において、第一元素に対応する塩をめっき浴中に添加しなかったこと、及び、第二元素としてスズ、ナトリウム又はクロムを、表4に記載の質量割合で多孔体中に含まれるように、SnSO4、Na2SO4又はCr2(SO4)3・nH2Oをめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料104~試料112の多孔体を作製した。
第2工程において、第一元素としてホウ素、鉄又はカルシウムを、表5に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2O、FeSO4・7H2O又はCaSO4・2H2Oをめっき浴中に添加したこと、及び、第二元素に対応する塩をめっき浴中に添加しなかったこと(表5)以外は<試料1~試料12>と同じにすることで、試料113~試料121の多孔体を作製した。
第2工程において、第一元素としてホウ素、鉄又はカルシウムを、表5に記載の質量割合で多孔体中に含まれるように、Na2B4O5(OH)4・8H2O、FeSO4・7H2O又はCaSO4・2H2Oをめっき浴中に添加したこと、及び、第二元素としてアルミニウムを、表5に記載の質量割合で多孔体中に含まれるように、Al2(SO4)3をめっき浴中に添加したこと以外は<試料1~試料12>と同じにすることで、試料122~試料130の多孔体を作製した。
<多孔体の物性分析>
上述の方法により得た試料1~試料48の多孔体及び試料101~試料130の多孔体に関し、これらの骨格の本体におけるニッケルおよびコバルトの合計質量に対するコバルトの質量割合を、それぞれ上記SEMに付帯のEDX装置(SEM部分:商品名「SUPRA35VP」、カールツァイスマイクロスコピー株式会社製、EDX部分:商品名「octane super」、アメテック株式会社製)を用いて調べた。具体的には、まず各試料の多孔体を切断した。次に切断された多孔体の骨格の断面を、上記EDX装置によって観察し、検出された各元素の原子濃度に基づいて当該コバルトの質量割合を求めた。その結果、試料1~試料48の多孔体及び試料101~試料130の多孔体の骨格本体におけるニッケルおよびコバルトの合計質量に対するコバルトの質量割合はいずれも、これらを作製するのに用いためっき浴に含まれるニッケルおよびコバルトの合計質量に対するコバルトの質量割合(Co/(Ni+Co)の質量比)と一致した。
さらに試料1~試料48の多孔体及び試料101~試料130の多孔体を空気極用集電体として、エルコーゲン社製のYSZセル(図9)と共に燃料電池を作製し(図8)、以下の評価項目で発電評価を行った。
以下の手順で、固体電解質の割れを評価した。すなわち、上記燃料電池を2000時間動作させた後のYSZセルを目視にて確認し、ひび割れおよびクラックの有無を確認することで、割れの有無を確認した。その結果を表1~表5に示す。
作製した燃料電池について、初期の作動電圧V1と2000時間後の作動電圧V2とを求め、下記の式により2000時間後の作動電圧維持率を算出し、その結果を下記の表1~表5に示した。表5中、「-」は、当該作動電圧維持率が測定できなかったことを示す。なお、それぞれの作動電圧V1、V2は、3回測定しその結果を平均することで求めた。
発電2000時間後の作動電圧維持率(%)=(V2/V1)×100
表1~表3の結果によれば、骨格の本体がニッケル、コバルト、第一元素及び第二元素を含み、上記第一元素の質量割合と上記第二元素の質量割合との合計が、上記骨格の本体に対して5ppm以上50000ppm以下である場合、燃料電池中に含まれている固体電解質に割れが観察されないことが分かった。さらに、当該燃料電池は、発電後2000時間後の作動電圧維持率が90%を超えており良好であることがわかった。特に上記コバルトの質量割合が上記ニッケルおよび上記コバルトの合計質量に対して、0.22である場合、上記コバルトの質量割合が0.58又は0.78である場合と比較して、発電後2000時間後の作動電圧維持率が特に良好であることがわかった。
以上のことから、実施例に係る多孔体は、燃料電池の空気極用集電体および水素極用集電体として適度な強度を有することが分かった。
Claims (11)
- 三次元網目状構造を有する骨格を備えた多孔体であって、
前記骨格の本体は、ニッケルとコバルトと第一元素と第二元素とを構成元素として含み、
前記コバルトの質量割合は、前記ニッケルおよび前記コバルトの合計質量に対して、0.2以上0.8以下であり、
前記第一元素は、ホウ素、鉄及びカルシウムからなる群より選ばれる少なくとも1種の元素からなり、
前記第二元素は、ナトリウム、マグネシウム、アルミニウム、ケイ素、カリウム、チタン、クロム、銅、亜鉛及びスズからなる群より選ばれる少なくとも1種の元素からなり、
前記第一元素の質量と前記第二元素の質量との合計の割合は、前記骨格の本体の質量に対して5ppm以上50000ppm以下である、多孔体。 - 前記コバルトの質量割合は、前記ニッケルおよび前記コバルトの合計質量に対して、0.2以上0.45以下又は0.6以上0.8以下である、請求項1に記載の多孔体。
- 前記第一元素の質量割合は、前記骨格の本体の質量に対して、4ppm以上40000ppm以下である、請求項1または請求項2に記載の多孔体。
- 前記第二元素の質量割合は、前記骨格の本体の質量に対して、1ppm以上10000ppm以下である、請求項1から請求項3のいずれか一項に記載の多孔体。
- 前記骨格の本体は、酸素を構成元素としてさらに含む、請求項1から請求項4のいずれか一項に記載の多孔体。
- 前記酸素は、前記骨格の本体において0.1質量%以上35質量%以下含まれる、請求項5に記載の多孔体。
- 前記骨格の本体は、スピネル型酸化物を含む、請求項5または請求項6に記載の多孔体。
- 前記骨格の本体は、その断面を3000倍の倍率で観察することにより観察像を得た場合、前記観察像の任意の10μm四方の領域において現われる長径1μm以上の空隙の数が5個以下である、請求項1から請求項7のいずれか一項に記載の多孔体。
- 前記骨格は、中空である、請求項1から請求項8のいずれか一項に記載の多孔体。
- 前記多孔体は、シート状の外観を有し、厚みが0.2mm以上2mm以下である、請求項1から請求項9のいずれか一項に記載の多孔体。
- 空気極用集電体および水素極用集電体を備える燃料電池であって、
前記空気極用集電体または前記水素極用集電体の少なくとも一方は、請求項1から請求項10のいずれか一項に記載の多孔体を含む、燃料電池。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE112020006285.6T DE112020006285T5 (de) | 2019-12-24 | 2020-12-09 | Poröser Körper und Brennstoffzelle diesen enthaltend |
JP2021567188A JP7567810B2 (ja) | 2019-12-24 | 2020-12-09 | 多孔体、およびそれを含む燃料電池 |
US17/780,252 US20220416255A1 (en) | 2019-12-24 | 2020-12-09 | Porous body and fuel cell including the same |
CN202080084710.0A CN114761593A (zh) | 2019-12-24 | 2020-12-09 | 多孔体和包含所述多孔体的燃料电池 |
KR1020227020957A KR20220115573A (ko) | 2019-12-24 | 2020-12-09 | 다공체 및, 그것을 포함하는 연료 전지 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019232469 | 2019-12-24 | ||
JP2019-232469 | 2019-12-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021131689A1 true WO2021131689A1 (ja) | 2021-07-01 |
Family
ID=76575463
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2020/045774 WO2021131689A1 (ja) | 2019-12-24 | 2020-12-09 | 多孔体、およびそれを含む燃料電池 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20220416255A1 (ja) |
JP (1) | JP7567810B2 (ja) |
KR (1) | KR20220115573A (ja) |
CN (1) | CN114761593A (ja) |
DE (1) | DE112020006285T5 (ja) |
WO (1) | WO2021131689A1 (ja) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016015217A (ja) * | 2014-07-01 | 2016-01-28 | 住友電気工業株式会社 | 膜電極複合体、膜電極複合体の製造方法、燃料電池及び燃料電池の製造方法 |
JP2017507452A (ja) * | 2013-12-26 | 2017-03-16 | リサーチ インスティチュート オブ インダストリアル サイエンス アンド テクノロジー | 固体酸化物形燃料電池用空気極集電体及びこれを含む固体酸化物形燃料電池 |
WO2019050301A1 (en) * | 2017-09-08 | 2019-03-14 | Lg Chem, Ltd. | INTERCONNECTION FOR SOLID OXIDE FUEL CELL, METHOD FOR MANUFACTURING SAME, AND SOLID OXIDE FUEL CELL |
WO2019244480A1 (ja) * | 2018-06-21 | 2019-12-26 | 住友電気工業株式会社 | 多孔体、それを含む集電体および燃料電池 |
WO2020235265A1 (ja) * | 2019-05-22 | 2020-11-26 | 住友電気工業株式会社 | 多孔体、それを含む燃料電池、およびそれを含む水蒸気電解装置 |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11154517A (ja) | 1997-11-21 | 1999-06-08 | Inoac Corporation:Kk | 二次電池用金属多孔体及びその製造方法 |
IT1399625B1 (it) * | 2010-04-19 | 2013-04-26 | Archimede Solar Energy Srl | Perfezionamenti nei collettori solari tubolari. |
JP2011246779A (ja) * | 2010-05-28 | 2011-12-08 | Sumitomo Electric Ind Ltd | アルミニウム構造体の製造方法およびアルミニウム構造体 |
JP5369050B2 (ja) * | 2010-05-20 | 2013-12-18 | 住友電気工業株式会社 | 高耐食性を有する金属多孔体 |
JP5569157B2 (ja) * | 2010-06-07 | 2014-08-13 | 住友電気工業株式会社 | ガス分解素子 |
US9466832B2 (en) * | 2010-06-21 | 2016-10-11 | Toyota Jidosha Kabushiki Kaisha | Lithium secondary battery including a nickel containing lithium complex oxide |
JP2012033423A (ja) * | 2010-08-02 | 2012-02-16 | Sumitomo Electric Ind Ltd | 金属多孔体およびその製造方法、それを用いた電池 |
JP5759169B2 (ja) | 2010-12-24 | 2015-08-05 | 住友電気工業株式会社 | 高耐食性を有する金属多孔体及びその製造方法 |
JP5691107B2 (ja) | 2011-01-17 | 2015-04-01 | 富山住友電工株式会社 | 高耐食性を有する金属多孔体及びその製造方法 |
JP6080088B2 (ja) * | 2011-10-27 | 2017-02-15 | 住友電気工業株式会社 | 多孔質集電体及びこれを用いた燃料電池 |
JP6653313B2 (ja) * | 2015-02-18 | 2020-02-26 | 住友電気工業株式会社 | ニッケル合金多孔体の製造方法 |
JP2017033917A (ja) * | 2015-08-04 | 2017-02-09 | 住友電気工業株式会社 | 金属多孔体、燃料電池、及び金属多孔体の製造方法 |
CN111742071A (zh) * | 2018-02-22 | 2020-10-02 | 住友电气工业株式会社 | 金属多孔体 |
-
2020
- 2020-12-09 WO PCT/JP2020/045774 patent/WO2021131689A1/ja active Application Filing
- 2020-12-09 JP JP2021567188A patent/JP7567810B2/ja active Active
- 2020-12-09 CN CN202080084710.0A patent/CN114761593A/zh active Pending
- 2020-12-09 KR KR1020227020957A patent/KR20220115573A/ko unknown
- 2020-12-09 US US17/780,252 patent/US20220416255A1/en active Pending
- 2020-12-09 DE DE112020006285.6T patent/DE112020006285T5/de active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017507452A (ja) * | 2013-12-26 | 2017-03-16 | リサーチ インスティチュート オブ インダストリアル サイエンス アンド テクノロジー | 固体酸化物形燃料電池用空気極集電体及びこれを含む固体酸化物形燃料電池 |
JP2016015217A (ja) * | 2014-07-01 | 2016-01-28 | 住友電気工業株式会社 | 膜電極複合体、膜電極複合体の製造方法、燃料電池及び燃料電池の製造方法 |
WO2019050301A1 (en) * | 2017-09-08 | 2019-03-14 | Lg Chem, Ltd. | INTERCONNECTION FOR SOLID OXIDE FUEL CELL, METHOD FOR MANUFACTURING SAME, AND SOLID OXIDE FUEL CELL |
WO2019244480A1 (ja) * | 2018-06-21 | 2019-12-26 | 住友電気工業株式会社 | 多孔体、それを含む集電体および燃料電池 |
WO2020235265A1 (ja) * | 2019-05-22 | 2020-11-26 | 住友電気工業株式会社 | 多孔体、それを含む燃料電池、およびそれを含む水蒸気電解装置 |
Also Published As
Publication number | Publication date |
---|---|
KR20220115573A (ko) | 2022-08-17 |
CN114761593A (zh) | 2022-07-15 |
JP7567810B2 (ja) | 2024-10-16 |
JPWO2021131689A1 (ja) | 2021-07-01 |
US20220416255A1 (en) | 2022-12-29 |
DE112020006285T5 (de) | 2022-12-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP7230826B2 (ja) | 多孔体、それを含む集電体および燃料電池 | |
US11466343B2 (en) | Metal porous body | |
WO2020235265A1 (ja) | 多孔体、それを含む燃料電池、およびそれを含む水蒸気電解装置 | |
US11757106B2 (en) | Porous body and fuel cell including the same | |
WO2021131689A1 (ja) | 多孔体、およびそれを含む燃料電池 | |
US11996589B2 (en) | Fuel cell | |
WO2020235267A1 (ja) | 多孔体、それを含む燃料電池、およびそれを含む水蒸気電解装置 | |
WO2020235266A1 (ja) | 多孔体、それを含む燃料電池、およびそれを含む水蒸気電解装置 | |
EP4043599A1 (en) | Surface-coated metallic porous body | |
WO2024070083A1 (ja) | 多孔体、多孔質集電体、およびそれらを備える固体酸化物形燃料電池 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 20907973 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2021567188 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20227020957 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 20907973 Country of ref document: EP Kind code of ref document: A1 |