WO2019163851A1 - チタン材、セパレータ、セル、および燃料電池 - Google Patents
チタン材、セパレータ、セル、および燃料電池 Download PDFInfo
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- WO2019163851A1 WO2019163851A1 PCT/JP2019/006410 JP2019006410W WO2019163851A1 WO 2019163851 A1 WO2019163851 A1 WO 2019163851A1 JP 2019006410 W JP2019006410 W JP 2019006410W WO 2019163851 A1 WO2019163851 A1 WO 2019163851A1
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- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/04—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings of inorganic non-metallic material
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
- C23C28/322—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer only coatings of metal elements only
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
- C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
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- 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
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0206—Metals or alloys
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- 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
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0213—Gas-impermeable carbon-containing materials
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- 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
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0215—Glass; Ceramic materials
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- 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
- H01M8/0204—Non-porous and characterised by the material
- H01M8/0223—Composites
- H01M8/0228—Composites in the form of layered or coated products
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- 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
- H01M2008/1095—Fuel cells with polymeric electrolytes
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- 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 invention relates to a titanium material, a separator for a fuel cell using the titanium material, a cell using the separator, and a fuel cell using the cell.
- Examples of the use of the metal material having excellent conductivity include a battery current collector and a battery case.
- a metal material is used as a metal current collector separator material.
- stainless steel or titanium is used as a metal material having excellent corrosion resistance. The reason why stainless steel has corrosion resistance is that an oxide film mainly composed of Cr 2 O 3 is formed on the surface thereof to protect the base material.
- titanium has corrosion resistance because an oxide film mainly composed of TiO 2 is formed on the surface to protect the base material.
- Patent Document 1 By providing a layer containing a noble metal on the surface of the titanium material, both corrosion resistance and conductivity of the titanium material can be achieved (for example, Patent Document 1).
- noble metals are expensive, and the use of noble metals increases the cost of the titanium material.
- Patent Documents 2 to 6 disclose titanium materials having a carbon-based conductive material provided on the surface layer.
- titanium carbide and a carbon film are formed in this order on a base material.
- the carbon film is formed by a plasma CVD method.
- an intermediate layer and a carbon layer are formed in this order on a base material.
- the intermediate layer includes titanium carbide and 0.1 to 40 atm% O (oxygen).
- the carbon layer contains graphite (graphite).
- an intermediate layer and a carbon-based conductive layer are formed in this order on a base material.
- the intermediate layer includes titanium carbide.
- the peak intensity ratio (D / G ratio) between the D band and the G band is 0.10 or more and 1.0 or less.
- an intermediate layer and a carbon layer are formed in this order on a base material.
- the intermediate layer includes titanium carbide.
- the carbon layer includes graphite.
- an intermediate layer and a carbon-based conductive layer are formed in this order on a base material.
- the intermediate layer includes titanium carbide.
- the carbon-based conductive layer has a two-layer structure including a carbon layer on the side close to the base material and a conductive resin layer on the side far from the base material.
- Patent Document 7 discloses a titanium material including a base material and an oxide film formed on the surface layer of the base material.
- the oxide film contains a conductive compound such as carbonitride.
- the conductive compound is protected by an oxide.
- Patent Document 8 discloses a titanium material having a layer made of diamond-like carbon on its surface.
- JP 2010-045052 A Japanese Patent No. 4825894 Japanese Patent No. 6122589 Japanese Patent No. 5556468 Japanese Patent No. 4888684 International Publication No. 2015/068559 International Publication No. 2014/021298 JP 2005-93172 A
- the titanium materials disclosed in Patent Documents 2 to 8 have a low initial contact resistance, they cannot be kept sufficiently low when exposed to a noble potential. This is because these titanium materials do not have sufficient oxidation resistance when exposed to precious potentials.
- a titanium material used in an environment exposed to a noble potential for example, a titanium material used for a separator of a polymer electrolyte fuel cell, needs to maintain a lower contact resistance even in such an environment. For this reason, the titanium materials disclosed in Patent Documents 2 to 8 are not sufficiently satisfactory as titanium materials used in such an environment.
- an object of the present invention is to provide a titanium material and a separator that can maintain a low contact resistance while realizing low contact resistance with a carbon layer and being less prone to surface oxidation even when exposed to a noble potential. That is.
- Another object of the present invention is to provide a fuel cell and a fuel cell that can maintain high power generation efficiency.
- the titanium material of the embodiment of the present invention is A substrate made of pure titanium or a titanium alloy; A carbon layer covering the surface of the substrate, The carbon layer contains non-graphitizable carbon and has an R value defined by the following formula (1) of 2.0 or more and 3.5 or less in Raman spectroscopic analysis using an argon laser having a wavelength of 532 nm.
- R I 1350 / I 1590 (1)
- I 1350 is the peak intensity near the wave number of 1.35 ⁇ 10 5 m ⁇ 1 in the Raman spectrum
- I 1590 is the peak intensity near the wave number of 1.59 ⁇ 10 5 m ⁇ 1 in the Raman spectrum.
- the separator of the fuel cell according to the embodiment of the present invention includes the titanium material.
- a cell of a fuel cell according to an embodiment of the present invention includes the separator.
- a fuel cell according to an embodiment of the present invention includes the cell.
- the titanium material according to the embodiment of the present invention realizes low contact resistance by the carbon layer, and even when exposed to a noble potential, surface oxidation hardly proceeds and can maintain low contact resistance.
- the cell and fuel cell of the embodiment of the present invention can maintain high power generation efficiency.
- FIG. 1 is a schematic cross-sectional view of a titanium material according to an embodiment of the present invention.
- FIG. 2A is a perspective view of a polymer electrolyte fuel cell according to an embodiment of the present invention.
- FIG. 2B is an exploded perspective view of a fuel cell (single cell).
- FIG. 3 is a diagram illustrating an example of a temporal change in current density during alternating electrolysis.
- FIG. 4 is a photograph showing an example of an electron beam diffraction pattern.
- FIG. 5 is a graph showing an example of the relationship between the lattice spacing d and the contrast intensity I.
- FIG. 6 is a diagram showing the configuration of an apparatus for measuring the contact resistance of a titanium material.
- FIG. 1 is a schematic cross-sectional view of a titanium material according to an embodiment of the present invention.
- the titanium material 7 includes a base material 8, a carbon layer 9 covering the surface of the base material 8, and a titanium carbonitride 10 formed between the base material 8 and the carbon layer 9.
- FIG. 1 shows a clear boundary between the base material 8, the carbon layer 9, and the titanium carbonitride 10.
- the structure continuously changes between the base material 8, the carbon layer 9, and the titanium carbonitride 10, and there is no clear interface.
- Such a characteristic is obtained by manufacturing the titanium material 7 by a manufacturing method described later.
- peeling is unlikely to occur between the base material 8, the carbon layer 9, and the titanium carbonitride 10.
- the substrate is made of pure titanium or a titanium alloy.
- pure titanium means a metal material containing 98.8% or more of Ti and the balance being impurities.
- pure titanium for example, JIS class 1 to JIS class 4 pure titanium can be used.
- JIS class 1 and JIS class 2 pure titanium have the advantages of being economical and easy to process.
- Tianium alloy means a metal material containing 70% or more of Ti, with the balance being an alloy element and an impurity element.
- the titanium alloy for example, JIS11, 13, or 17 for corrosion resistance, or JIS60 for high strength can be used.
- the carbon layer realizes a low contact resistance of the titanium material. That is, it is not necessary to use a noble metal for the titanium material in order to realize a low contact resistance. For this reason, the cost of the titanium material can be reduced.
- the carbon layer includes non-graphitizable carbon.
- the carbon layer has an R value defined by the following formula (1) of 2.0 or more and 3.5 or less.
- R I 1350 / I 1590 (1)
- I 1350 is the peak intensity near the wave number of 1.35 ⁇ 10 5 m ⁇ 1 (1350 cm ⁇ 1 ) in the Raman spectrum.
- I 1590 is a peak intensity near the wave number of 1.59 ⁇ 10 5 m ⁇ 1 (1590 cm ⁇ 1 ) in the Raman spectrum.
- I 1350 is an integrated intensity with a wave number ranging from 1.00 ⁇ 10 5 to 1.50 ⁇ 10 5 m ⁇ 1 .
- I 1590 is an integrated intensity with a wave number in the range of 1.50 ⁇ 10 5 to 1.80 ⁇ 10 5 m ⁇ 1 .
- the peak in the vicinity of 1.35 ⁇ 10 5 m ⁇ 1 corresponds to a D band that does not originate from the graphite (graphite) structure.
- the peak near 1.59 ⁇ 10 5 m ⁇ 1 corresponds to the G band due to the graphite structure. Therefore, the larger the R value, the smaller the proportion of graphite in the carbon layer.
- R value When the R value is 2.0 or more, it becomes easy to ensure high corrosion resistance of the carbon layer in a humid environment. In order to fully exhibit this effect, it is preferable that R value is 2.2 or more. When the R value is 3.5 or less, the electric conductivity can be increased as compared with the case where the R value exceeds 3.5. When the thickness of the carbon layer is 10 to 100 nm, the electric conductivity necessary for the separator of the fuel cell can be ensured by setting the R value to 3.5 or less. In order to fully exhibit this effect, it is preferable that R value is 3.0 or less.
- Non-graphitizable carbon means amorphous carbon that cannot be converted to graphite even when heated to 3300K under normal pressure or reduced pressure. Whether or not the carbon layer contains non-graphitizable carbon is determined by a transmission electron microscope (TEM; Transmission Electron Microscope) of the carbon layer, which is a diffraction image due to the d002 laminated structure of graphite, that is, (002 This can be determined from the diffraction image of the surface.
- TEM Transmission Electron Microscope
- 002 for crystal refers to the Miller index for the graphite structure.
- the carbon layer is graphitizable carbon. That is, it can be determined that it does not contain non-graphitizable carbon.
- this spot-like diffraction image is not observed and a ring-like diffraction image due to the d002 laminated structure is observed, it can be determined that the carbon layer contains non-graphitizable carbon.
- the transmission electron microscope image of diamond-like carbon see Patent Document 8
- ring-shaped and speckled diffraction images due to the d002 laminated structure are not observed. Therefore, diamond-like carbon is not non-graphitizable carbon.
- carbon is gasified (CO or CO 2 ) when the potential is exposed to a noble state.
- CO gasified
- Such gasification is suppressed when the carbon layer is non-graphitizable carbon.
- the thickness of the carbon layer is unlikely to decrease even when the potential is exposed to a noble state. That is, such a carbon layer is excellent in corrosion resistance.
- non-graphitizable carbon is hard and has excellent wear resistance.
- the separator of the polymer electrolyte fuel cell is used in contact with the electrode membrane.
- a carbon layer containing non-graphitizable carbon contacts the electrode film. The carbon layer is not easily damaged by contact with the electrode film.
- the carbon layer has an R value of 2.0 or more and 3.5 or less, and includes non-graphitizable carbon, so that it has excellent corrosion resistance, high hardness, and excellent wear resistance.
- the thickness of the carbon layer is preferably 10 to 100 nm, for example.
- the carbon layer has conductivity, but the conductivity is low compared to a metal such as Ti. For this reason, when the carbon layer is thickened, the increase width of the resistance value in the thickness direction of the carbon layer is increased.
- the thickness of the carbon layer is preferably 100 nm or less, and more preferably 50 nm or less. Moreover, if the carbon layer is too thin, it is easily damaged. When the carbon layer breaks, the base (base material, titanium carbonitride, etc.) is exposed at that portion and is not protected by the carbon layer. In order to sufficiently protect the base with the carbon layer, the thickness of the carbon layer is preferably 10 nm or more, and more preferably 20 nm or more.
- the thickness of the carbon layer is measured as follows.
- the carbon content is measured while performing sputtering in the thickness direction from the surface of the carbon layer by glow discharge emission analysis (GDOES; Glow Discharge Optical Emission Spectrometry).
- GDOES glow discharge emission analysis
- the depth at which the C content reaches 1 ⁇ 2 of the maximum value is defined as the thickness of the carbon layer.
- the discharge part is a circle having a diameter of 4 mm. Therefore, the thickness of the carbon layer is an average thickness of the carbon layer in a circular region having a diameter of 4 mm. As will be described later, since the carbon layer does not necessarily cover the entire surface of the base, this circular region may include a portion where the carbon layer does not exist.
- the substrate exposed from the carbon layer for example, titanium carbonitride, dissolves when exposed to a noble potential and becomes titanium oxide by oxidation.
- titanium oxide As the titanium oxide, TiO 2 is easily formed.
- TiO 2 has substantially no conductivity. In this case, on the surface of the titanium material, substantially only the portion covered with the carbon layer bears conductivity.
- the ratio of the area of the portion covered with the carbon layer to the surface area of the base is defined as “carbon layer coverage”.
- the coverage of the carbon layer is preferably 60% or more, more preferably 80% or more, and 100 % Is most preferred.
- the coverage of the carbon layer is measured as follows. Mapping by I 1350 (unit: cps) of the titanium material surface is performed by Raman spectroscopic analysis of the titanium material surface. The ratio of the area of the area where I 1350 has an integrated intensity of 1/5 or more of the maximum integrated intensity with respect to the area of the mapped area is defined as the coverage of the carbon layer.
- titanium carbonitride is not an essential component. Titanium carbonitride is represented by the chemical formula TiC 1-x N x (0 ⁇ x ⁇ 0.8). As shown in FIG. 1, the titanium carbonitride may be present dispersed on the substrate. In this case, the form of titanium carbonitride is, for example, granular. Titanium carbonitride may be continuously formed in a sheet form on the surface of the substrate.
- the electrical conductivity of titanium carbonitride includes the electrical conductivity of titanium carbide (for example, 1.00 ⁇ -1 ⁇ m -1 ⁇ 10 6 ) and the electrical conductivity of titanium nitride (for example, 3.80 ⁇ -1 ⁇ m -1 ⁇ 10 6 ) (Non-Patent Document 1). Further, the conductivity of TiO is 0.52 ⁇ ⁇ 1 ⁇ m ⁇ 1 ⁇ 10 6 (Non-patent Document 2). The electrical conductivity of Ti 3 O 5 is 0.0035 ⁇ ⁇ 1 ⁇ m ⁇ 1 ⁇ 10 6 (Non-patent Document 3).
- the conductivity of Ti 4 O 7 is 0.15 ⁇ ⁇ 1 ⁇ m ⁇ 1 ⁇ 10 6 (Non-patent Document 3). That is, the conductivity of titanium carbonitride is higher than that of TiO x (1 ⁇ x ⁇ 2), which is a low-order oxide of titanium. Therefore, when the titanium material of the present invention contains titanium carbonitride, the resistance of the surface layer portion can be lowered as compared with the conventional titanium material using TiC or TiO x .
- the titanium material of the present invention contains titanium carbonitride
- the titanium material preferably contains an appropriate amount of titanium carbonitride.
- the integrated intensity of the peak due to the (101) plane of the ⁇ -Ti phase is set to “Ti (101)”
- titanium carbonitride The integrated intensity of the peak due to the (200) plane is “TiCN (200)”.
- Carbonide abundance ratio is defined as TiCN (200) / Ti (101). The abundance ratio of carbonitride is preferably 0.10 to 0.45, for example.
- the abundance ratio of the carbonitride is preferably 0.10 or more.
- the abundance ratio of the carbonitride is set to 0. 0 in order to suppress generation of titanium oxide having no conductivity. It is preferable that it is 45 or less.
- the average particle diameter of titanium carbonitride is preferably 20 nm or more and not more than the thickness of the carbon layer, for example. Titanium carbonitride can exhibit the effect of closely adhering the carbon layer and the substrate. In order to sufficiently exhibit this effect, the average particle size of titanium carbonitride is preferably 20 nm or more. On the other hand, as shown in FIG. 1, granular titanium carbonitride protrudes from the surface of the substrate. For this reason, if the average particle size of titanium carbonitride is too large, when a large pressure is applied to the surface of the titanium material, the titanium carbonitride may break through the carbon layer and be exposed. In order to avoid such a situation, it is preferable that the average particle diameter of titanium carbonitride is not more than the thickness of the carbon layer.
- the average particle size of titanium carbonitride shall be measured as follows. First, a thin film sample for TEM observation is prepared from a titanium material by FIB (Focused Ion Beam) ⁇ (micro) sampling method. An electron microscope image is obtained for this sample, and in the field of view, titanium carbonitride particles are identified from EDS (Energy Dispersive X-ray Spectrometry) analysis and electron diffraction analysis. The field of view is a square area with a side length of about 0.17 ⁇ m. Then, within the field of view, for each of all the particles identified as titanium carbonitride, the average of the major axis and the minor axis is obtained to obtain the average particle diameter of each particle.
- EDS Electronic Data Dispersive X-ray Spectrometry
- This average particle diameter is averaged for all particles to obtain the average particle diameter of titanium carbonitride in the field of view.
- the average particle diameter of titanium carbonitride in the three fields of view is averaged to obtain the average particle diameter of titanium carbonitride for the target titanium material.
- Titanium carbide may be formed between the base material and the carbon layer.
- the titanium material of the embodiment of the present invention is, for example, An oxidation step of oxidizing the surface of a substrate made of pure titanium or a titanium alloy; After the oxidation step, one or more selected from the group consisting of polyvinylidene chloride, sugar, cellulose, phenol resin, furfuryl alcohol resin, acrylic resin, epoxy resin, thermosetting polyimide resin, and charcoal A carbon source supply step of supplying a resin coating containing the substrate to the surface of the substrate; After the carbon source supplying step, the base material can be manufactured by a manufacturing method including a heat treatment step of heat-treating at 620 to 820 ° C. in an atmosphere having an oxygen partial pressure of 0.1 Pa or less.
- the manufacturing method may further include a cold rolling step of applying a lubricant containing amine to the surface of the base material before the oxidation step, and cold rolling the base material coated with the lubricant.
- the resin paint may further contain nitrogen.
- this manufacturing method includes an oxidation process, a carbon source supply process, and a heat treatment process.
- the surface (surface layer portion) of the base material made of pure titanium or a titanium alloy is oxidized by, for example, heat treatment in an oxidizing atmosphere or anodizing treatment.
- an oxide film having a thickness of, for example, 10 to 50 nm is formed on the surface of the substrate. It is not preferable to form an oxide film by adding Ti that is not derived from the base material to the base material by means such as vapor deposition, because the adhesion of the titanium oxide film to the base material may become insufficient.
- the oxidizing atmosphere can be an air atmosphere, for example.
- the heat treatment temperature is, for example, 350 ° C. or more and 700 ° C. or less
- the heating time is, for example, 5 to 90 minutes after reaching a predetermined temperature.
- the heat treatment condition is, for example, 5 minutes at 600 ° C. in an air atmosphere.
- the anodizing treatment can be performed using an aqueous solution used for general anodizing of titanium, for example, an aqueous phosphoric acid solution or an aqueous sulfuric acid solution.
- the anodizing voltage is 15 V or more, and the upper limit is a voltage that does not cause dielectric breakdown (about 150 V).
- the anodizing voltage is, for example, 30V.
- Anodization may be performed by, for example, alternating electrolysis. In this case, the surface of the substrate is oxidized when the substrate finally becomes a positive potential (current density) regardless of the pattern of alternating electrolysis (change in voltage (current density) with time).
- a carbon source supply step is performed.
- the carbon source supplying step one kind selected from the group consisting of polyvinylidene chloride, sugar, cellulose, phenol resin (phenol formaldehyde resin), furfuryl alcohol resin, acrylic resin, epoxy resin, thermosetting polyimide resin, and charcoal.
- the resin coating material containing 2 or more types is supplied to the surface of a base material. Since titanium oxide is formed in the surface layer portion of the base material before supplying the resin paint in the oxidation step, the resin paint is supplied on the titanium oxide.
- the resin paint may be, for example, a resin in which fine particles of this resin are dispersed in water.
- a phenol resin, a furfuryl alcohol resin, an acrylic resin, an epoxy resin, and a thermosetting polyimide resin are preferable in that they can be easily formed into a paint.
- the resin paint may contain organic substances other than polyvinylidene chloride, sugar, cellulose, phenol resin (phenol formaldehyde resin), furfuryl alcohol resin, acrylic resin, epoxy resin, thermosetting polyimide resin, and charcoal.
- porous carbon that is permeable to gas or water may be obtained. If the carbon layer is porous carbon, the base cannot be sufficiently protected.
- a phenol resin, a furfuryl alcohol resin, an acrylic resin, a thermosetting polyimide resin, and an epoxy resin have a high carbonization yield in the heat treatment step. For this reason, when these resins are used, dense non-graphitizable carbon that is not porous carbon can be obtained in the heat treatment step.
- thermosetting polyimide resin it is particularly preferable to use a thermosetting polyimide resin as the carbon source.
- thermosetting polyimide resin include PMR (in situ Polymerization of Monomer Reactants) type (for example, terminal nadic acid type), terminal acetylene type, and bismaleimide type.
- the thickness of the resin paint supplied to the surface of the substrate (hereinafter referred to as “coating thickness”) is, for example, 5 to 40 ⁇ m.
- the coating thickness is the thickness of the resin after the organic solvent and water contained in the resin paint are removed by drying. If the coating thickness is less than 5 ⁇ m, the carbon in the resin coating may be consumed in the reduction of the titanium oxide formed on the substrate surface layer part in the heat treatment step and may not remain. In this case, a carbon layer cannot be formed. If the coating thickness exceeds 40 ⁇ m, the thickness of the carbon layer formed in the heat treatment step may exceed the preferred upper limit of 100 nm. In this case, the resistance value in the thickness direction of the carbon layer cannot be made sufficiently low.
- a heat treatment process is performed.
- the substrate with the resin coating supplied on the surface is heat treated at 620 to 820 ° C. in an atmosphere having an oxygen partial pressure of 0.1 Pa or less (hereinafter referred to as “low oxygen partial pressure atmosphere”).
- the low oxygen partial pressure atmosphere can be, for example, an Ar atmosphere or a reduced pressure (vacuum) atmosphere.
- the heat treatment time can be, for example, 30 to 120 seconds after the atmospheric temperature reaches a predetermined temperature.
- the titanium oxide on the surface layer of the base material is reduced by carbon in the resin paint to become titanium metal.
- non-graphitizable carbon is formed from the carbon in the resin coating that was not consumed by the reduction of the titanium oxide.
- a carbon layer containing non-graphitizable carbon and having an R value of 2.0 or more and 3.5 or less is formed.
- the heat treatment temperature and the heat treatment time are appropriately selected according to the type of resin paint, the coating thickness, and the like.
- titanium carbide may be formed between the base material and the carbon layer.
- a carbon layer containing non-graphitizable carbon is obtained in the heat treatment step from polyvinylidene chloride, sugar, cellulose, phenol resin, furfuryl alcohol resin, acrylic resin, epoxy resin, thermosetting polyimide resin, and charcoal.
- these resins when carbonized in a heat treatment step, the crosslinking formed in the initial stage is easily maintained, and the formation of a planar arrangement of crystallites (formation of a crystal structure of graphite) and growth are hindered. These resins are hardly graphitized even when heat-treated at a high temperature (for example, 2000 ° C.).
- the resin paint is mainly composed of an easily graphitizable organic material such as petroleum coke, coal coke, and polyvinyl chloride
- a carbon layer having an R value of less than 2.0 is obtained in the heat treatment step.
- the carbon layer cannot secure high corrosion resistance in a humid environment, and is easily gasified when exposed to a noble potential.
- non-graphitizable carbon is not obtained from any organic material in the heat treatment step.
- many thermosetting resins become non-graphitizable carbon when heated.
- At least one of the following measures (i) and (ii) is performed.
- the cold rolling process described below is further performed.
- a resin paint further containing nitrogen is used.
- Cold rolling process is performed before the oxidation process.
- a lubricant containing an amine (cold rolling oil) is applied to the surface of the base material, and the base material coated with the lubricant is cold-rolled.
- the amine may be contained in the lubricant as a component of the extreme pressure additive, for example.
- a compound containing nitrogen resulting from amine remains in the vicinity of the surface of the substrate. This compound remains in the vicinity of the surface of the substrate even after degreasing or alkali cleaning after the cold rolling (the final finish rolling in the case of performing multiple cold rollings).
- the titanium oxide formed in the oxidation process is reduced by the carbon in the resin paint in the heat treatment process. At that time, titanium in the base material, nitrogen existing in the vicinity of the surface of the base material, and carbon in the resin paint react to form titanium carbonitride between the base material and the carbon layer.
- the resin paint may contain, for example, ammonium polyacrylate as a nitrogen source.
- Ammonium polyacrylate functions as a thickener for resin coatings.
- the carbon constituting the carbon layer is carbon remaining after being consumed by reduction of the titanium oxide. Further, titanium constituting titanium carbonitride is produced by reducing titanium oxide formed on the surface layer portion of the base material. As a result, in the obtained titanium material, the structure continuously changes between the carbon layer, titanium carbonitride, and the base material. For this reason, the adhesion between the carbon layer, titanium carbonitride, and the substrate is high.
- FIG. 2A is a perspective view of a polymer electrolyte fuel cell according to an embodiment of the present invention.
- FIG. 2B is an exploded perspective view of a fuel cell (single cell). As shown in FIGS. 2A and 2B, the fuel cell 1 is an assembly of single cells. In the fuel cell 1, a plurality of cells are stacked and connected in series.
- a fuel electrode film (anode) 3 and an oxidant electrode film (cathode) 4 are laminated on one surface and the other surface of the solid polymer electrolyte membrane 2, respectively.
- separator 5a, 5b is piled up on both surfaces of this laminated body. Separator 5a, 5b is provided with the above-mentioned titanium material.
- the fuel electrode film 3 and the oxidant electrode film 4 include a diffusion layer made of a carbon sheet and a catalyst layer provided so as to be in contact with the surface of the diffusion layer.
- the carbon sheet is composed of carbon fibers. Carbon paper or carbon cloth is used as the carbon sheet.
- the catalyst layer includes a particulate platinum catalyst, catalyst-supporting carbon, and a fluorine resin having a hydrogen ion (proton) exchange group.
- MEA Membrane Electrode Assembly
- a fuel gas (hydrogen or hydrogen-containing gas) A flows through a flow path 6a that is a groove formed in the separator 5a.
- the fuel gas is supplied to the fuel electrode film 3.
- the fuel gas passes through the diffusion layer and reaches the catalyst layer.
- an oxidizing gas B such as air flows through the flow path 6b which is a groove formed in the separator 5b.
- the oxidizing gas is supplied to the oxidant electrode film 4.
- the oxidizing gas passes through the diffusion layer and reaches the catalyst layer.
- Separator 5a, 5b is low in initial contact resistance with electrode films 3 and 4 by being provided with the above-mentioned titanium material. Moreover, this low contact resistance is maintained in the separator environment of the polymer electrolyte fuel cell 1 because the surface oxidation hardly proceeds when the titanium material is exposed to a noble potential.
- the flow path 6b may be formed in the other surface of the separator 5a (surface opposite to the surface where the flow path 6a is formed).
- a channel 6a may be formed on the other surface of the separator 5b (the surface opposite to the surface on which the channel 6b is formed).
- the separators 5a and 5b having the shape in which the flow paths (grooves) are formed can be obtained by press-molding a thin plate-like titanium material.
- separators 5a and 5b including a titanium material including the base material and the above-described carbon layer covering the surface of the base material can be obtained.
- the fuel cell of the present invention is not limited to a polymer electrolyte fuel cell, and may be, for example, a solid electrolyte fuel cell, a molten carbonate fuel cell, or a phosphoric acid fuel cell.
- Base materials A and B described below were prepared as base materials.
- the base material A is obtained by forming JIS type 1 titanium into a plate having a thickness of 0.1 mm by cold rolling.
- Cold rolling was performed by applying a rolling lubricant containing amine on the surface of titanium.
- the rolling lubricant was used by adding 1% of an antioxidant lubricant additive manufactured by Kaneda. This lubricating additive contained a dialkyldiphenylamine.
- the base material A was not annealed.
- the base material B is obtained by subjecting the base material A to alkali degreasing and then performing bright annealing (BA; Bright Annealing) at 720 ° C. for 30 seconds in an Ar atmosphere using a continuous furnace.
- the Ar atmosphere was obtained by flowing industrial compressed argon gas having a purity of 99.995% or more and an O content of less than 3 ppm into a continuous furnace.
- Some base materials B were pickled with 10% nitric acid and 2% aqueous hydrofluoric acid to remove N originating from the lubricating additive (the base material of Invention Example 1 described later). With respect to the other base materials B and A, it was predicted that N derived from the lubricating additive remained on the surface.
- Both base material A and base material B had a width of 50 mm and a length of 100 mm.
- Table 1 shows the compositions of the base material A and the base material B.
- the base material A and the base material B had the same content of C, H, N, O, and Fe.
- Oxidation step The oxidation step was carried out by anodizing the substrate, heat-treating it in an oxidizing atmosphere, or treating it with an acid solution. Anodization was performed in a 10% sulfuric acid aqueous solution having a liquid temperature of 35 ° C.
- the substrate was subjected to alternating reverse (PR) electrolysis. At that time, the potential of the base material in the final electrolytic treatment was precious.
- the current density at the peak was 20 mA / cm 2 .
- FIG. 3 the time change of the current density at the time of alternating electrolysis is shown.
- An oxide film titanium oxide was formed on the surface of the substrate by making the potential of the substrate in the final electrolytic treatment noble.
- the heat treatment in an oxidizing atmosphere was performed using a gas replacement muffle furnace manufactured by AS ONE while introducing air into the furnace at a flow rate of 0.5 L / min from an air cylinder.
- the substrate was heated at 550 ° C. for 5 minutes.
- a 20% nitric acid aqueous solution was used for the treatment with the acid solution.
- a resin paint was applied to the surface of the substrate.
- the resin paint used is based on water-based acrylic resin, based on water-based acrylic resin and added with a thickener, based on phenolic resin, and based on petroleum-based tar resin , And a thermosetting polyimide resin as a main component.
- Resin paints other than those mainly composed of petroleum-based tar resins and those mainly composed of thermosetting polyimide resins were obtained by dispersing resin fine particles in at least one of an organic solvent and water.
- the petroleum tar resin was dissolved in toluene to obtain a resin paint.
- the thermosetting polyimide resin was dissolved in N-methyl-2-pyrrolidone (NMP) to obtain a resin paint.
- NMP N-methyl-2-pyrrolidone
- the resin paint mainly composed of water-based acrylic resin was NIPPE HOME Co., Ltd. hexacoat PS-K water-based primer.
- the thickener added to this resin coating was A-30 manufactured by Toagosei Co., Ltd.
- the amount of the thickener added to the aqueous acrylic resin was 5% by mass.
- the thickener contained ammonium polyacrylate.
- the resin paint mainly composed of phenol resin was New Aknon NC manufactured by Kansai Paint.
- the resin coating mainly composed of thermosetting polyimide resin was a resin solution in which granular bisallyl nadiimide (BANI-M manufactured by Maruzen Petrochemical Co., Ltd.) was dissolved in NMP.
- the mass ratio of bisallylnadiimide and NMP was 2: 8.
- thermosetting polyimide resin as a main component was used (Example 15 of the present invention described later).
- a thermosetting treatment was performed at 250 ° C. for 20 minutes instead of the drying treatment.
- the mass before application of the resin paint and the mass after application and drying were measured, and the difference between these masses was taken as the mass of the applied resin paint.
- average coating thickness was computed from the density of the resin paint after drying, the mass of the applied resin paint, and the surface area of a base material. Density of the resin coating after drying, acrylic resins for paints 1.18 g / cm 3, phenol for resin coating 1.07 g / cm 3, for petroleum tar coating 1.18 g / cm 3, thermosetting polyimide
- the resin paint was 1.13 g / cm 3 .
- Heat treatment step The substrate on which the resin coating was supplied on the surface in the carbon source supply step was heat-treated in an argon atmosphere using a precision atmosphere continuous simulator MT960008 manufactured by ULVAC SHINKU-RIKO. The heat treatment was performed by flowing an argon gas having the same composition as that when the base material A was prepared by annealing the base material A. At that time, the oxygen partial pressure in the argon atmosphere was 0.1 Pa. The dew point was ⁇ 50 ° C.
- a titanium material described in Patent Document 2 was produced.
- a titanium plate having the same composition as the base material B and having a thickness of 40 mm was prepared.
- a rolling oil die roll (registered trademark) manufactured by Daido Chemical Industry Co., Ltd. was applied to the titanium plate.
- Dyroll (registered trademark) was a rolling oil containing no amine.
- This titanium plate was heated to 800 ° C. and rolled to a thickness of 15 mm.
- the titanium plate was reheated to 800 ° C. and then rolled to a thickness of 1 mm.
- the titanium plate was reheated to 800 ° C. and then rolled to a thickness of 0.2 mm.
- the titanium plate was placed in a plasma CVD apparatus capable of introducing gas. After depressurizing the inside of the apparatus, H 2 was introduced at a flow rate of 30 sccm (Standard cc / min) and Ar was introduced at a flow rate of 30 sccm from the gas introduction hole of the apparatus, so that the pressure in the apparatus was 450 Pa. Subsequently, a DC voltage of 400 V was applied between the anode plate and the titanium plate, and the titanium plate was heated to 600 ° C. Thereafter, 30 ccm of benzene gas for film formation was introduced into the apparatus. Thereby, a carbon layer was grown on the surface of the titanium plate. Film formation was completed when the thickness of the carbon layer reached 50 nm. The obtained sample was used as the titanium material of Conventional Example 1.
- a titanium material described in Patent Document 3 was produced.
- the base material B was coated with a graphite paint (slurry containing graphite) with a No. 10 bar coater.
- a graphite paint slurry containing graphite
- As the graphite high-purity natural graphite (SNE manufactured by SEC Carbon Co., Ltd .; average particle size of 7 ⁇ m (hereinafter, the SNE of the same company has an average particle size of 7 ⁇ m)) was used.
- the graphite paint was obtained by dispersing graphite in a 0.8 mass% carboxymethylcellulose aqueous solution. The graphite content of the graphite paint was 8% by mass.
- the base material coated with the graphite paint was naturally dried for one day.
- the substrate was subjected to skin pass rolling with a rolling reduction of 1%. Furthermore, this base material was heat-treated at 700 ° C. for 2 minutes in an Ar gas atmosphere containing 50 ppm of O 2 and cooled to 100 ° C. or lower. The obtained sample was used as the titanium material of Conventional Example 2.
- a titanium material described in Patent Document 4 was produced.
- a graphite paint containing 20%, 10%, and 70% by mass% of phenol resin, high-purity natural graphite (SNE manufactured by SEC Carbon Co., Ltd.), and butyl carbitol was produced.
- This graphite paint was applied to the front and back surfaces of the base material B so as to have a thickness of 5 ⁇ m.
- the sample was then air dried for 1 day. Furthermore, this sample was heat-treated at 550 ° C. for 3 minutes in a vacuum furnace. The obtained sample was used as the titanium material of Conventional Example 3.
- a titanium material described in Patent Document 5 was produced.
- a JIS type 1 titanium material was used as the base material.
- This base material had a thickness of 200 ⁇ m and a BA (bright annealing) finish.
- a graphite paint was applied to the surface (one side) of the substrate so that the thickness was 10 ⁇ m.
- High-purity natural graphite SNE manufactured by SEC Carbon Co.
- the graphite paint was obtained by dispersing graphite in a 1% by mass aqueous methylcellulose solution.
- the graphite content of the graphite paint was 8% by mass.
- the obtained sample was air-dried for 1 day.
- the thickness of the sample after drying was 220 ⁇ m including the base material and the graphite paint.
- the sample was cold-rolled.
- the thickness of the sample after rolling was 100 ⁇ m. That is, the rolling reduction was 54%.
- the sample was heat-treated at 700 ° C. for 5 minutes in an Ar atmosphere. The obtained sample was used as the titanium material of Conventional Example 4.
- a titanium material described in Patent Document 6 was produced.
- the graphite paint was applied to the surface (one side) of the base material B so that the thickness was 10 ⁇ m.
- As the graphite powder high-purity natural graphite (SNE manufactured by SEC Carbon Co.) was used.
- the graphite paint was obtained by dispersing graphite in a 0.8 mass% carboxymethylcellulose aqueous solution. The graphite content of the graphite paint was 8% by mass. The obtained sample was air-dried for 1 day.
- this sample was subjected to cold rolling with a rolling reduction of 2% without applying a lubricant using a cold rolling mill. Thereafter, this sample was heat-treated at 650 ° C. for 5 minutes under a pressure of 2 ⁇ 10 ⁇ 4 Torr (2.67 ⁇ 10 ⁇ 2 Pa) in a vacuum furnace.
- graphite paint was applied to both surfaces of the obtained sample with a bar coater.
- the thickness of the applied graphite paint was 10 ⁇ m per one side of the sample.
- the graphite paint was obtained by dispersing carbon black powder (Valcan (registered trademark) XC72 manufactured by Cabot Corporation) and graphite powder (SNE manufactured by SEC Carbon Corporation) in a liquid in which a phenol resin was dissolved in butyl carbitol.
- the mass ratio of the phenol resin in the graphite paint, the carbon black powder, and the graphite powder was 75: 22.5: 2.5.
- This sample was heat-treated at 400 ° C. for 1 minute in the air.
- the obtained sample was used as a titanium material of Conventional Example 5.
- a titanium material described in Patent Document 7 was produced.
- the base material B was degreased with acetone.
- the surface of this substrate was coated with TiCN by ion plating.
- the thickness of the coated TiCN was 2 ⁇ m per side of the substrate.
- the obtained sample was immersed in a 20% nitric acid aqueous solution at 40 ° C. for 2 minutes to perform passivation treatment.
- this sample was immersed in a 50 ° C. aqueous solution containing 0.1% by mass of the corrosion inhibitor Hibiron (registered trademark) manufactured by Sugimura Chemical Industry Co., Ltd. for 5 minutes, and subjected to stabilization treatment.
- the obtained sample was used as a titanium material of Conventional Example 6.
- a titanium material described in Patent Document 8 was produced.
- the substrate made of the base material A was coated with a diamond-like carbon film.
- a hall ion source (Hall-Accelerator-for-low-voltage-Continuous-Operation) was used for the coating treatment of the diamond-like carbon film.
- a hydrocarbon gas, specifically methane gas was used as a raw material. Then, discharge plasma of methane gas was generated in the apparatus, and a beam of hydrocarbon ions generated thereby was generated.
- a diamond-like carbon film was formed by applying a hydrocarbon ion beam to the substrate surface. Methane gas was flowed into the apparatus at a flow rate of 3 mL / min. The substrate current was 750 mA.
- the acceleration voltage of hydrocarbon ions (the voltage between the anode and the cathode) was 650V.
- the substrate temperature was 600 ° C.
- the obtained sample was used as the titanium material of Conventional Example 7.
- Table 2 shows the production conditions for each titanium material.
- the obtained sample was measured for carbon nitride content, carbon layer thickness, Raman spectrum peak intensity, carbon layer coverage, average particle size of titanium carbonitride, and contact resistance.
- the integrated strength of titanium carbonitride near the surface of the titanium material was determined using an R-X diffraction device RINT2500 manufactured by Rigaku Corporation.
- the conditions for X-ray diffraction were as follows. Incident angle: 0.3 ° (deg)
- Scan Step scan at 0.04 ° step Fixed time for each step: 2 seconds
- the strongest diffraction peaks Ti of ⁇ -Ti were all due to the (101) plane. Moreover, the strongest peak of titanium carbonitride was due to the (200) plane in any of the samples in which the peak of titanium carbonitride was detected.
- the integrated intensity of the peak due to the (101) plane of ⁇ -Ti and the peak due to the (200) plane of titanium carbonitride was determined. The integrated intensity of the peaks was obtained after performing peak separation by fitting a diffraction curve including these peaks using asymmetric Pearson VII as a profile function.
- the integrated intensity of the peak due to the (101) plane of the ⁇ -Ti phase is referred to as “Ti (101)”.
- the integrated intensity of the peak due to the (200) plane of titanium carbonitride is referred to as “TiCN (200)”.
- TiCN (200) / Ti (101) was determined as the abundance ratio of carbonitride (TiCN / Ti).
- Carbon Layer Thickness The carbon layer thickness was measured by the above-described method by glow discharge emission analysis.
- the glow discharge emission analysis was measured using a Marcus type high frequency glow discharge emission analyzer GD-profiler 2 manufactured by Horiba. Under the following measurement conditions, the C content was measured while performing sputtering in the depth direction from the surface. The reason why the discharge region is a circular region having a diameter of 4 mm is to obtain average information on the surface of the titanium material.
- Discharge area Circular area with a diameter of 4 mm
- RF output 35 W
- Argon pressure 600 Pa
- Analytical elements Ti, O, C, H, N Measurement depth: From the initial surface to 3 ⁇ m Measurement mode: Pulse sputtering mode
- Raman spectroscopic analysis The Raman spectroscopic analysis of the sample surface was performed using the Raman spectrophotometer LabRAM HR Evolution manufactured by HORIBA, Ltd. under the following measurement conditions. Excitation wavelength: 532 nm Diffraction grating engraving: 600 lines / mm ND filter transmittance: 10% Objective lens magnification: 50x
- the integrated intensity in the wave number range of 1.00 to 1.50 ⁇ 10 5 m ⁇ 1 was set to the peak intensity (I 1350 ) near 1.35 ⁇ 10 5 m ⁇ 1 .
- the integrated intensity in the wave number range of 1.50 to 1.80 ⁇ 10 5 m ⁇ 1 was defined as the peak intensity (I 1590 ) near 1.59 ⁇ 10 5 m ⁇ 1 .
- the R value (I 1350 / I 1590 ) was determined from these peak intensities.
- Diffraction pattern of transmission electron microscope image Whether or not the carbon layer contains non-graphitizable carbon was determined by the method described above based on the diffraction pattern of the transmission electron microscope image.
- the sample for observation was sampled as a thin film sample from the titanium material by performing FI evaporation on the surface of the titanium material and then using the FIB ⁇ sampling method.
- the sample for observation had a cross section perpendicular to the surface of the titanium material. The thickness of this sample was 100 nm or less.
- a vacuum deposition apparatus (JEE-420T) manufactured by JEOL Ltd. was used for Au deposition.
- SMI3050SE made by Hitachi High-Tech Science was used for sampling by the FIB ⁇ sampling method.
- a mesh made of Mo was used.
- Electron beam diffraction was performed by a microelectron diffraction method with an electron beam probe diameter of 1 nm so that a diffraction pattern of the carbon layer could be obtained even if the carbon layer had a thickness of several nm.
- the acceleration voltage was 200 kV.
- the observation magnification was 500,000 times.
- a transmission electron microscope image was obtained for a square region having a side of 0.17 ⁇ m.
- the electron diffraction pattern of non-graphitizable carbon has a halo ring (hereinafter simply referred to as “ring”) in the vicinity of a position corresponding to a lattice spacing of 3.4 mm (lattice spacing of (002) plane of graphite). Is observed). Whether or not the sample (carbon layer) contains non-graphitizable carbon was determined by the following procedure. This determination method is based on the technique described in “3.1.4 Crystallinity of carbon compared with electron diffraction pattern” of Non-Patent Document 4.
- the lattice spacing d can be obtained from the relationship of the following formula (A).
- rd L ⁇ (A)
- r Radial radius measured from a photograph of a transmission electron microscope image (electron diffraction pattern)
- L TEM camera length (distance between the sample and the imaging unit of the camera)
- ⁇ the wavelength of the electron beam.
- FIG. 4 shows an example of an electron diffraction pattern.
- a ring (halo ring; indicated as “002” in FIG. 4) is observed in the vicinity of the position corresponding to the lattice spacing (3.4 mm) of the (002) plane of graphite.
- a ring R10 (halo ring) and a ring R11 (halo ring) are observed outside the ring 002.
- the ring R10 is a ring in which a ring appearing at a position corresponding to the lattice plane interval of the (100) plane and a ring appearing at a position corresponding to the lattice plane interval of the (101) plane are overlapped.
- the ring R11 is a ring in which a ring that appears at a position corresponding to the lattice spacing of the (110) plane and a ring that appears at a position corresponding to the lattice spacing of the (112) plane overlap.
- the graph (FIG. 5) which shows the relationship between the grid surface space
- the obtained transmission electron microscope image was read with a scanner to obtain digital data of the image.
- the relationship between the lattice spacing d and the contrast intensity (relative intensity) I was determined.
- the relationship between d and I is large between the case where the contrast intensity on the straight line passing through the spot is adopted and the case where the contrast intensity on the straight line not passing through the spot is adopted.
- the presence or absence of spots due to the (002) plane of graphite was confirmed.
- spots were present the contrast intensity on a straight line passing through the center of the diffraction pattern and spots due to the (002) plane of graphite was employed.
- the contrast intensity along a circle having a center at the center of the diffraction pattern and having a radius corresponding to 3.4 mm in lattice spacing was obtained.
- a point (hereinafter referred to as “maximum point”) at which the contrast intensity is maximum (maximum) on this circumference is assumed to be the center of the spot.
- the contrast intensity along a straight line passing through the maximum point and the center of the diffraction pattern was obtained.
- the contrast intensity along a straight line passing through an arbitrary point on the circumference and the center of the diffraction pattern was obtained.
- FIG. 5 shows an example of a graph showing the relationship between the lattice plane distance d and the contrast intensity I.
- FIG. 5 shows the relationship between the lattice spacing d and the contrast intensity I in the portion on the right side from the center for the diffraction pattern of Example 1 of the present invention.
- the center of the diffraction pattern in the case of the present embodiment, a ring-shaped pattern
- the center of the diffraction pattern is on the right side, that is, on the side where the lattice spacing d is large.
- a peak is observed in the vicinity of 3.4 mm. This peak corresponds to a ring due to the (002) plane of graphite. Whether or not this peak is due to non-graphitizable carbon was determined by the half-value width of this peak. In obtaining the half width, the peak height h was obtained by removing the background. Similarly, a graph indicating the relationship between the lattice spacing d and the contrast intensity I was created for the left portion from the center of the ring, and the half width was obtained.
- the carbon layer is made of non-graphitizable carbon at the position where the transmission electron microscope image is obtained. It was determined that there was. In this case, it was determined that there were no spots due to the (002) plane of graphite.
- Average particle diameter of titanium carbonitride The average particle diameter of titanium carbonitride was determined by the above-described method for specifying titanium carbonitride particles on an electron microscope image.
- the FIB ⁇ sampling method was carried out using SMI3050SE manufactured by Hitachi High-Tech Science. A mesh made of Mo was used.
- the electron microscope observation was performed using a field emission transmission electron microscope JEM-2100F manufactured by JEOL. This electron microscope was provided with an EDS analyzer JED-2300T. The observation magnification was 500,000 times. Electron diffraction was ⁇ -fraction.
- FIG. 6 is a diagram showing the configuration of an apparatus for measuring the contact resistance of a titanium material. Using this apparatus, the contact resistance of each sample was measured. Referring to FIG. 6, first, the prepared sample 11 is sandwiched between a pair of carbon papers (TGP-H-90 manufactured by Toray Industries, Inc.) 12 used as an electrode film (gas diffusion layer) for a fuel cell. This was sandwiched between a pair of gold-plated electrodes 13. The area of each carbon paper 12 was 1 cm 2 .
- TGP-H-90 manufactured by Toray Industries, Inc.
- the obtained resistance value is a value obtained by adding the contact resistances of both surfaces of the sample 11, and is divided by 2 to obtain a contact resistance value per one surface of the sample 11. The contact resistance measured in this way was defined as the first contact resistance.
- the load applied between the pair of gold-plated electrodes 13 is 5 kgf / cm 2 (4.90 ⁇ 10 5 Pa), 10 kgf / cm 2 (9.81 ⁇ 10 5 Pa), 20 kgf / cm 2 (19.6 ⁇ 10 5 Pa), 10 kgf / cm 2 , and 5 kgf / cm 2 were changed. This change in weight was repeated 10 times. Thereafter, the pressure was set to 10 kgf / cm 2 (9.81 ⁇ 10 5 Pa), and the contact resistance was measured as in the first contact resistance measurement. The contact resistance measured in this way was defined as the contact resistance after 10 times load.
- Evaluation results Table 3 shows the evaluation results of each titanium material.
- the contact resistance hardly increased by applying the load 10 times in any of the initial state, the corrosion resistance test, and the oxidation test.
- the contact resistance after 10 times load after the corrosion resistance test was a low value of 10 m ⁇ ⁇ cm 2 or less.
- the contact resistance after 10 times load after the oxidation test (hereinafter referred to as “contact resistance after heavy load”) was a low value of 14 m ⁇ ⁇ cm 2 or less. That is, all of the inventive examples 1 to 15 could maintain a low contact resistance even when exposed to a noble potential.
- Example 1 The contact resistance after heavy load of Invention Example 1 was higher than the contact resistance after heavy load of Invention Examples 2 to 15.
- titanium carbonitride was detected, whereas in Example 1 of the present invention, titanium carbonitride was not detected. Therefore, titanium carbonitride contributed to the reduction of contact resistance. it is conceivable that.
- Inventive Example 1 since the heat treatment was performed in a state where N (nitrogen) was not substantially present on the surface of the substrate, titanium carbonitride was not formed.
- the R value of Invention Example 14 was the upper limit of the range of the R value defined in the present invention.
- the contact resistance after heavy load of Invention Example 14 was 10 m ⁇ ⁇ cm 2 or less, which was higher than, for example, Invention Examples 2 to 3 having R values of 2.0 to 2.9. .
- Invention Example 15 was obtained by applying a resin coating containing a thermosetting polyimide resin.
- the coverage of the carbon layer exceeded 90%. This is because the amount of carbon that volatilizes as a gas such as hydrocarbon, CO, and CO 2 in the heat treatment step is small due to the use of the thermosetting polyimide resin, and many of the components of the resin paint remain. it is conceivable that.
- the increase in the contact resistance value from the initial state after the corrosion resistance test or the oxidation test was small. That is, the sample of Invention Example 15 was excellent in corrosion resistance. This is presumably because TiCN and TiC that ensure high conductivity were sufficiently protected due to the denseness of the carbon layer and the high coverage of the carbon layer.
- Comparative Example 1 did not satisfy the requirements of the present invention in that the R value was less than 2. This is related to the use of a resin paint mainly composed of petroleum-based tar resin as a carbon source. Comparative Example 2 did not satisfy the requirements of the present invention in that the R value exceeded 3.5. This is related to the fact that the temperature of the heat treatment was low. The contact resistance after heavy load of Comparative Examples 1 and 2 was a high value exceeding 14 m ⁇ ⁇ cm 2 .
- the R values of Conventional Examples 1, 3, and 4 were less than 2.
- the graphite coating was applied to the base material, a carbon layer mainly composed of graphite was formed on these samples. Therefore, the R values of Conventional Examples 2 and 5 are also less than 2.
- carbon layers mainly composed of graphite are formed in Conventional Examples 2 to 5, these carbon layers are not non-graphitizable carbon. Since the process of forming a carbon layer was not performed when producing Conventional Example 6, Conventional Example 6 does not have a carbon layer. Therefore, none of the conventional examples satisfy the requirements of the present invention.
- the contact resistance after heavy load of Conventional Examples 1 to 7 was a high value of 17 m ⁇ ⁇ cm 2 or more.
- the contact resistance after heavy load of Conventional Example 7 was an extremely high value exceeding 300 m ⁇ ⁇ cm 2 . That is, Conventional Examples 1 to 7 cannot maintain a low contact resistance when exposed to a noble potential.
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Abstract
Description
純チタンまたはチタン合金からなる基材と、
前記基材の表面を覆う炭素層と、を備え、
前記炭素層は、難黒鉛化性炭素を含むとともに、波長532nmのアルゴンレーザを用いたラマン分光分析において、下記式(1)で定義されるR値が2.0以上3.5以下である。
R=I1350/I1590…(1)
ただし、I1350は、ラマンスペクトルにおいて波数が1.35×105m-1近傍のピーク強度であり、
I1590は、ラマンスペクトルにおいて波数が1.59×105m-1近傍のピーク強度である。
本発明の実施形態の燃料電池のセルは、上記セパレータを備える。
本発明の実施形態の燃料電池は、上記セルを備える。
図1は、本発明の一実施形態に係るチタン材の模式断面図である。チタン材7は、基材8、基材8の表面を覆う炭素層9、および基材8と炭素層9との間に形成された炭窒化チタン10とを備える。
基材は、純チタンまたはチタン合金からなる。ここで、「純チタン」とは、98.8%以上のTiを含有し、残部が不純物からなる金属材を意味する。純チタンとして、たとえば、JIS1種~JIS4種の純チタンを用いることができる。これらのうち、JIS1種およびJIS2種の純チタンは、経済性に優れ、加工しやすいという利点を有する。「チタン合金」とは、70%以上のTiを含有し、残部が合金元素と不純物元素とからなる金属材を意味する。チタン合金として、たとえば、耐食用途のJIS11種、13種、もしくは17種、または高強度用途のJIS60種を用いることができる。
炭素層により、チタン材の低い接触抵抗が実現される。すなわち、低い接触抵抗を実現するためにチタン材に貴金属を用いる必要はない。このため、チタン材のコストを低くすることができる。炭素層は、難黒鉛化性炭素を含む。さらに、炭素層は、波長532nmのアルゴンレーザを用いたラマン分光分析において、下記式(1)で定義されるR値が2.0以上3.5以下である。
R=I1350/I1590…(1)
ただし、I1350は、ラマンスペクトルにおいて波数が1.35×105m-1(1350cm-1)近傍のピーク強度である。I1590は、ラマンスペクトルにおいて波数が1.59×105m-1(1590cm-1)近傍のピーク強度である。
本発明のチタン材において、炭窒化チタンは、必須の構成要素ではない。炭窒化チタンは、化学式TiC1-xNx(0≦x≦0.8)で表される。炭窒化チタンは、図1に示すように、基材上に分散して存在していてもよい。この場合、炭窒化チタンの形態は、たとえば、粒状である。炭窒化チタンは、基材の表面に、シート状に連続して形成されていてもよい。
基材と炭素層との間には、炭化チタン(TiC)が形成されていてもよい。
本発明の実施形態のチタン材は、たとえば、
純チタンまたはチタン合金からなる基材の表面を酸化させる酸化工程と、
前記酸化工程の後、ポリ塩化ビニリデン、砂糖、セルロース、フェノール樹脂、フルフリルアルコール樹脂、アクリル樹脂、エポキシ樹脂、熱硬化性ポリイミド樹脂、および木炭からなる群より選択される1種または2種以上を含む樹脂塗料を、前記基材の表面に供給する炭素源供給工程と、
前記炭素源供給工程の後、前記基材を、酸素分圧が0.1Pa以下の雰囲気中、620~820℃で熱処理する熱処理工程と、を含む製造方法により製造することができる。
前記樹脂塗料は、窒素をさらに含んでもよい。
この工程では、純チタンまたはチタン合金からなる基材の表面(表層部)を、たとえば、酸化性雰囲気中での熱処理、または陽極酸化処理によって酸化させる。これにより、基材の表面に、厚さが、たとえば、10~50nmの酸化皮膜を形成する。蒸着のような手段により、基材に由来しないTiを基材上に付加して酸化皮膜を形成すると、基材に対するチタン酸化物皮膜の密着性が不十分になることがあるので好ましくない。
酸化性雰囲気は、たとえば大気雰囲気とすることができる。厚さが10~50nm程度の酸化皮膜を得るため、熱処理温度は、たとえば、350℃以上700℃以下とし、加熱時間は、たとえば、所定の温度に到達してから、5~90分とすることができる。熱処理条件は、たとえば、大気雰囲気中、600℃で5分とする。
陽極酸化処理は、チタンの一般的な陽極酸化に用いられる水溶液、たとえば、リン酸水溶液、硫酸水溶液などを用いて実施することが可能である。陽極酸化の電圧は、15V以上で、絶縁破壊を起こさない電圧(約150V)を上限とする。陽極酸化の電圧は、たとえば、30Vである。陽極酸化は、たとえば、交番電解により実施してもよい。この場合、交番電解のパターン(電圧(電流密度)の時間変化)によらず、最後に基材が+の電位(電流密度)になれば、基材の表面は酸化される。
酸化工程の後、炭素源供給工程を実施する。炭素源供給工程では、ポリ塩化ビニリデン、砂糖、セルロース、フェノール樹脂(フェノールホルムアルデヒド樹脂)、フルフリルアルコール樹脂、アクリル樹脂、エポキシ樹脂、熱硬化性ポリイミド樹脂、および木炭からなる群より選択される1種または2種以上を含む樹脂塗料を、基材の表面に供給する。樹脂塗料を供給する前の基材の表層部には、酸化工程でチタン酸化物が形成されているので、樹脂塗料は、チタン酸化物の上に供給される。
炭素源供給工程の後、熱処理工程を実施する。熱処理工程では、表面に樹脂塗料が供給された基材を、酸素分圧が0.1Pa以下の雰囲気(以下、「低酸素分圧雰囲気」という。)中、620~820℃で熱処理する。低酸素分圧雰囲気は、たとえば、Ar雰囲気、または減圧(真空)雰囲気とすることができる。熱処理時間は、たとえば、雰囲気の温度が所定温度に到達してから、30~120秒とすることができる。
(i) 以下に説明する冷間圧延工程をさらに実施する。
(ii) 樹脂塗料として、窒素をさらに含むものを用いる。
冷間圧延工程は、酸化工程の前に実施する。冷間圧延工程では、基材の表面にアミンを含む潤滑剤(冷間圧延油)を塗布し、潤滑剤が塗布された基材を冷間圧延する。アミンは、たとえば、極圧添加剤の成分として潤滑剤に含まれていてもよい。
樹脂塗料は、窒素源として、たとえば、ポリアクリル酸アンモニウムを含んでもよい。ポリアクリル酸アンモニウムは、樹脂塗料の増粘剤として機能する。窒素を含む樹脂塗料を用いる場合は、炭素源供給工程で表面に樹脂塗料が供給された基材に対して、熱処理工程を実施すると、酸化工程で形成されたチタン酸化物は、樹脂塗料中の炭素により還元される。その際、基材中のチタン、ならびに樹脂塗料中の炭素および窒素が反応して、基材と炭素層との間に炭窒化チタンが形成される。
図2Aは、本発明の一実施形態に係る固体高分子形燃料電池の斜視図である。図2Bは、燃料電池のセル(単セル)の分解斜視図である。図2Aおよび図2Bに示すように、燃料電池1は単セルの集合体である。燃料電池1において、複数のセルが積層され直列に接続されている。
1.基材の準備および冷間圧延工程
基材として、以下に説明する基材Aおよび基材Bを準備した。基材Aは、JIS1種チタンを、冷間圧延により、厚さが0.1mmの板状にしたものである。冷間圧延は、チタンの表面にアミンを含む圧延潤滑剤を塗布して行った。圧延潤滑剤は、カネダ社製の酸化防止用潤滑添加剤を1%添加して用いた。この潤滑添加剤は、ジアルキルジフェニールアミンを含んでいた。
酸化工程は、基材を、陽極酸化すること、酸化性雰囲気中で熱処理すること、または、酸溶液で処理することにより実施した。陽極酸化は、液温が35℃の10%硫酸水溶液中で行った。基材には、交番(PR;Periodic Reverse)電解を実施した。その際、最終電解処理での基材の電位を貴とした。ピーク時の電流密度は、20mA/cm2とした。図3に、交番電解時の電流密度の時間変化を示す。最終電解処理での基材の電位を貴としたことにより、基材の表面には、酸化皮膜(チタン酸化物)が形成された。
酸溶液による処理には、20%硝酸水溶液を用いた。
基材の表面に、樹脂塗料を塗布した。用いた樹脂塗料は、水性アクリル樹脂を主成分とするもの、水性アクリル樹脂を主成分とし増粘剤を添加したもの、フェノール樹脂を主成分とするもの、石油系タール樹脂を主成分とするもの、および熱硬化性ポリイミド樹脂を主成分とするもののいずれかであった。石油系タール樹脂を主成分とするもの、および熱硬化性ポリイミド樹脂を主成分とするもの以外の樹脂塗料は、樹脂の微粒子を有機溶剤および水の少なくとも一方で分散させたものであった。石油系タール樹脂は、トルエンに溶解して樹脂塗料とした。熱硬化性ポリイミド樹脂は、N-メチル-2-ピロリドン(NMP)に溶解して、樹脂塗料とした。
炭素源供給工程で表面に樹脂塗料が供給された基材を、ULVAC SHINKU-RIKO社製精密雰囲気連続シミュレータMT960008を用いて、アルゴン雰囲気中で熱処理した。熱処理は、基材Aを焼鈍して基材Bを作製する際と同じ組成のアルゴンガスを流して行った。その際、アルゴン雰囲気の酸素分圧は、0.1Paであった。露点は、-50℃とした。
以上のチタン材に加えて、従来のチタン材の試料(従来例)を作製した。従来例の製造方法は、以下の通りである。
本発明例について、リガク社製X線回折装置RINT2500を用いて、チタン材表面近傍の炭窒化チタンの積分強度を求めた。X線回折の条件は、次の通りとした。
入射角:0.3°(deg)
X線:Co-Kα線
励起:加速電圧を30kVとした100mAの電子線照射
測定対象の回折角度(2θ)の範囲:10~110°
スキャン:0.04°のステップでのステップスキャン
各ステップの固定時間:2秒
炭素層の厚さを、上述のグロー放電発光分析による方法により測定した。グロー放電発光分析は、堀場製作所社製のマーカス型高周波グロー放電発光分析装置GD-profiler2を用いて測定した。以下の測定条件で、表面から深さ方向にスパッタを行いながら、C含有率を測定した。放電領域を直径が4mmの円形領域としたのは、チタン材表面の平均的な情報を得るためである。
放電領域:直径が4mmの円形領域
RF出力:35W
アルゴン圧力:600Pa
分析対象元素:Ti、O、C、H、N
測定深さ:初期の表面から3μmまで
測定モード:パルススパッタリングモード
堀場製作所社製のラマン分光測定装置 LabRAM HR Evolutionを用い、以下の測定条件で、試料表面のラマン分光分析を行った。
励起波長:532nm
回折格子刻線:600本/mm
NDフィルタ透過率:10%
対物レンズ倍率:50倍
炭素層が難黒鉛化性炭素を含むか否かを、透過電子顕微鏡像の回折パターンに基づく上述の方法により判定した。観察用の試料は、チタン材表面にAu蒸着を施した後、FIBμサンプリング法により、チタン材から、薄膜試料としてサンプリングした。観察用の試料は、チタン材の表面に垂直な断面を有していた。この試料の厚さは、100nm以下であった。Au蒸着には、日本電子社製の真空蒸着装置(JEE-420T)を用いた。FIBμサンプリング法によるサンプリングには、日立ハイテクサイエンス製SMI3050SEを用いた。メッシュは、Mo製のものを用いた。
・炭素層の表面近傍(最表面から5nmの深さ位置)における、互いに0.05μm離れた2箇所
・炭素層の深さ方向中央の位置における、互いに0.05μm離れた2箇所
・炭素層において基材近傍(基材と炭素層との界面から炭素層側へ5nmの深さ位置)における1箇所
rd=Lλ…(A)
ただし、
r:透過電子顕微鏡像(電子線回折パターン)の写真から実測する動径
L:TEMのカメラ長(試料とカメラの撮像部との距離)
λ:電子線の波長
である。TEMのカメラ長および電子線の波長は、具体的には、L=787mm、λ=0.00251nmであった。
読み取り倍率:100%
解像度:1200dpi
グレースケール階調:8ビット(黒と白との間を28=256階調とした。)
炭素層の被覆率を、上述のラマン分光分析による方法により求めた。その際、測定領域は、一辺が110μmの正方形とした。この測定領域について、各辺を90等分して得られるマトリクス状の領域の各々を分析点として、I1350を測定した。すなわち、分析点の数は、90×90=8100点であった。
電子顕微鏡像上で炭窒化チタンの粒子を特定する上述の方法により、炭窒化チタンの平均粒径を求めた。FIBμサンプリング法は、日立ハイテクサイエンス社製SMI3050SEを用いて実施した。メッシュは、Mo製のものを用いた。電子顕微鏡観察は、日本電子社製の電界放出形透過電子顕微鏡JEM-2100Fを用いて実施した。この電子顕微鏡には、EDS分析装置JED-2300Tが付属していた。観察倍率は50万倍とした。電子線回折は、μ-ディフラクションとした。
得られたチタン材の試料について、非特許文献3に記載されている方法に準じ、接触抵抗を測定した。図6は、チタン材の接触抵抗を測定する装置の構成を示す図である。この装置を用い、各試料の接触抵抗を測定した。図6を参照して、まず、作製した試料11を、燃料電池用の電極膜(ガス拡散層)として使用される1対のカーボンペーパ(東レ(株)製TGP-H-90)12で挟み込み、これを1対の金めっき電極13で挟んだ。各カーボンペーパ12の面積は、1cm2であった。
得られたチタン材の試料(繰り返し変動する荷重を加えていないもの)を、90℃、pH3のH2SO4水溶液に96時間浸漬した後、水洗して乾燥させた。そして、上述の方法により、試料の接触抵抗(初回および10回加重後)を測定した。耐食性が良好ではない場合には、チタン材表層の不動態皮膜が成長するので、浸漬前(初期)と比較し接触抵抗が上昇する。
得られたチタン材の試料を、80℃、pH3のH2SO4水溶液に浸漬した。この状態で、白金を対極とし、試料電位を、SHE(標準水素電極)に対して0.9Vの貴な電位にした。この電位を24時間維持した後、試料を水洗して乾燥させた。そして、上述の方法により、試料の接触抵抗(初回および10回加重後)を測定した。炭素層の耐酸化性が良好ではない場合には、炭素層の厚さが減少するので下地を十分に保護することができない。この場合、チタン材表層の不動態皮膜が成長するので、上記H2SO4水溶液に浸漬する前(初期)と比較し接触抵抗が上昇する。
表3に、各チタン材の評価結果を示す。
5a、5b:セパレータ
7:チタン材
8:基材
9:炭素層
10:炭窒化チタン
11:試料(チタン材)
Claims (6)
- 純チタンまたはチタン合金からなる基材と、
前記基材の表面を覆う炭素層と、を備えるチタン材であって、
前記炭素層は、難黒鉛化性炭素を含むとともに、波長532nmのアルゴンレーザを用いたラマン分光分析において、下記式(1)で定義されるR値が2.0以上3.5以下である、チタン材。
R=I1350/I1590…(1)
ただし、I1350は、ラマンスペクトルにおいて波数が1.35×105m-1近傍のピーク強度であり、
I1590は、ラマンスペクトルにおいて波数が1.59×105m-1近傍のピーク強度である。 - 請求項1に記載のチタン材であって、
前記炭素層の厚さが10~100nmである、チタン材。 - 請求項1または2に記載のチタン材であって、
前記基材と前記炭素層との間に形成された炭窒化チタンをさらに備える、チタン材。 - 請求項1~3に記載のチタン材を備える、燃料電池のセパレータ。
- 請求項4に記載のセパレータを備える、燃料電池のセル。
- 請求項5に記載のセルを備える、燃料電池。
Priority Applications (5)
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US16/964,825 US20210066729A1 (en) | 2018-02-21 | 2019-02-20 | Titanium material, separator, fuel cell, and fuel cell stack |
EP19756725.8A EP3758117A1 (en) | 2018-02-21 | 2019-02-20 | Titanium material, separator, cell, and fuel cell |
JP2019532147A JP6610842B1 (ja) | 2018-02-21 | 2019-02-20 | チタン材、セパレータ、セル、および燃料電池 |
CN201980014165.5A CN111742434A (zh) | 2018-02-21 | 2019-02-20 | 钛材、分隔件、电池单元和燃料电池 |
KR1020207022993A KR20200106185A (ko) | 2018-02-21 | 2019-02-20 | 티타늄재, 세퍼레이터, 셀 및 연료 전지 |
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JP2021055144A (ja) * | 2019-09-30 | 2021-04-08 | 日本製鉄株式会社 | 複合材、燃料電池用セパレータ、燃料電池セル、および燃料電池スタック、ならびに複合材の製造方法 |
CN114267849A (zh) * | 2020-10-01 | 2022-04-01 | 丰田自动车株式会社 | 燃料电池 |
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JP7375723B2 (ja) * | 2020-10-16 | 2023-11-08 | トヨタ自動車株式会社 | セパレータ及びセパレータの製造方法 |
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Cited By (3)
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JP2021055144A (ja) * | 2019-09-30 | 2021-04-08 | 日本製鉄株式会社 | 複合材、燃料電池用セパレータ、燃料電池セル、および燃料電池スタック、ならびに複合材の製造方法 |
JP7339525B2 (ja) | 2019-09-30 | 2023-09-06 | 日本製鉄株式会社 | 複合材、燃料電池用セパレータ、燃料電池セル、および燃料電池スタック、ならびに複合材の製造方法 |
CN114267849A (zh) * | 2020-10-01 | 2022-04-01 | 丰田自动车株式会社 | 燃料电池 |
Also Published As
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EP3758117A1 (en) | 2020-12-30 |
JP6610842B1 (ja) | 2019-11-27 |
JPWO2019163851A1 (ja) | 2020-04-09 |
KR20200106185A (ko) | 2020-09-11 |
CN111742434A (zh) | 2020-10-02 |
US20210066729A1 (en) | 2021-03-04 |
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