JP6359157B2 - Laminate and electrochemical device - Google Patents

Description

  The present invention relates to a laminate and an electrochemical device.

  Conventionally, in a fuel cell stack which is one of electrochemical devices, a manifold for supporting the fuel cell is used. The manifold is generally composed of stainless steel containing iron and chromium.

  Here, in order to suppress deterioration of the electrode of the fuel cell due to chromium volatilized from the manifold, a method of covering the outer surface of the manifold with a coating layer with insulating ceramics has been proposed (see Patent Document 1).

Japanese Patent Laying-Open No. 2015-035418

  However, when the fuel cell is operated for a long time, the coating layer may peel from the manifold. Such peeling of the coating layer is not limited to the manifold of the fuel cell stack, but occurs in all components of electrochemical devices used in a high temperature environment.

  This invention is made | formed in view of the above-mentioned situation, and it aims at providing the laminated body and electrochemical device which can suppress peeling of a coating layer.

  The laminate according to the present invention includes a metal member, a coating layer, and a first intermediate layer. The metal member contains iron and chromium. The coating layer covers at least a part of the surface of the metal member and contains an insulating ceramic material as a main component. The first intermediate layer is disposed between the metal member and the coating layer, contains an insulating ceramic material as a main component, and contains titanium oxide.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body and electrochemical device which can suppress peeling of a coating layer can be provided.

The perspective view which shows the structure of a fuel cell stack The perspective view which shows the structure of a fuel cell PP sectional view of FIG. Perspective view showing the structure of the manifold QQ sectional view of FIG.

(Configuration of fuel cell stack 1)
The configuration of the fuel cell stack 1 will be described with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the fuel cell stack 1.

  The fuel cell stack 1 includes a plurality of fuel cells 100 (an example of an electrochemical cell), a manifold 200, and a fuel introduction passage 300.

  The plurality of fuel cells 100 are erected on the manifold 200. Each fuel cell 100 is disposed so as to protrude from the manifold 200. One end of each fuel cell 100 is bonded to the manifold 200 by a bonding material (not shown) (for example, amorphous glass). The other end of each fuel cell 100 is a free end. The fuel cells 100 are electrically connected to each other by a current collecting member (not shown). In the present embodiment, a plurality of fuel cells 100 are arranged in two rows, but the number of rows and the number of fuel cells 100 included in each row can be changed as appropriate.

  The manifold 200 supports a plurality of fuel cells 100. The manifold 200 is formed in a hollow shape. The manifold 200 supplies the fuel gas introduced into the manifold 200 from the fuel introduction passage 300 to each fuel cell 100. The fuel introduction passage 300 is erected on the manifold 200. The fuel introduction passage 300 may be welded to the manifold 200.

  When the fuel cell stack 1 is operated, high-temperature (for example, 600 to 800 ° C.) fuel gas (hydrogen or the like) sequentially passes through the fuel introduction passage 300, the manifold 200, and the inside of each fuel cell 100, so While being released from the other end, an oxygen-containing gas (such as air) passes through the gap between the fuel cells 100.

1. Configuration of Fuel Cell 100 The configuration of the fuel cell 100 will be described with reference to the drawings. FIG. 2 is a perspective view showing the configuration of the fuel cell 100. 3 is a cross-sectional view taken along the line PP in FIG.

  The fuel cell 100 includes a support substrate 10, a fuel electrode 20, an interconnector 30, a solid electrolyte layer 40, a reaction preventing film 50, an air electrode 60, and an air electrode current collecting film 70. The fuel electrode 20, the solid electrolyte membrane 40, the reaction preventing membrane 50, and the air electrode 60 constitute the power generating element portion A. As shown in FIG. 2, the fuel cell 100 according to the present embodiment is a so-called horizontal stripe fuel cell in which four power generation element portions A are arranged at predetermined intervals in the longitudinal direction. Four power generation element portions A are arranged on both main surfaces of the support substrate 10. However, since the configuration of each power generation element portion A is the same, in the following, the configuration of one power generation element portion A will be described. Mainly explained.

  The support substrate 10 is formed in a flat plate shape. The support substrate 10 has a plurality of fuel gas passages 11 extending in the longitudinal direction. The fuel gas supplied from the manifold 200 passes through each of the plurality of fuel gas flow paths 11.

The support substrate 10 is made of a porous material that does not have electronic conductivity. Examples of the porous material that does not have electron conductivity include CSZ (calcia stabilized zirconia), 8YSZ (yttria stabilized zirconia), 10YSZ, Y ₂ O ₃ (yttria), MgO (magnesium oxide), or MgAl ₂ O. ₄ (magnesia alumina spinel) and a mixture of MgO can be used.

  The support substrate 10 may contain a transition metal that can function as a catalyst for promoting a reforming reaction of a fuel gas (a hydrocarbon-based gas reforming catalyst). Ni is suitable as such a transition metal. The support substrate 10 may contain Ni in the form of NiO (nickel oxide).

The fuel electrode 20 is disposed in a recess 12 formed on the main surface of the support substrate 10. The fuel electrode 20 has a fuel electrode current collector 21 and a fuel electrode active part 22. The fuel electrode current collector 21 includes a substance having electronic conductivity. The fuel electrode current collector 21 can be composed of, for example, NiO—YSZ, NiO—Y ₂ O ₃ , NiO—CSZ, or the like. The thickness of the fuel electrode current collector 21 can be 50 to 500 μm. The anode active part 22 is disposed in the recess 21 a of the anode current collector 21. The fuel electrode active part 22 can be composed of, for example, NiO-YSZ, NiO-GDC (gadolinium-doped ceria) or the like. The thickness of the fuel electrode active part 22 can be 5 to 30 μm.

The interconnector 30 is disposed in the recess 21 b of the fuel electrode current collector 21. The interconnector 30 is formed flush with the fuel electrode 20. The interconnector 30 can be made of a dense material having electronic conductivity. The interconnector 30 can be made of, for example, LaCrO ₃ (lanthanum chromite), (Sr, La) TiO ₃ (strontium titanate), or the like. The thickness of the interconnector 30 can be 10 to 100 μm.

  The solid electrolyte membrane 40 covers a part of the fuel electrode 20 and the interconnector 30. Since the fuel electrode 20 is covered with the interconnector 30 and the solid electrolyte membrane 40, mixing of fuel gas and air is prevented. The solid electrolyte membrane 40 can be made of a dense material that has oxygen ion conductivity and does not have electron conductivity. The solid electrolyte membrane 40 can be composed of, for example, YSZ or LSGM (lanthanum gallate). The thickness of the solid electrolyte membrane 40 can be 3-50 micrometers.

  The reaction preventing film 50 is disposed between the solid electrolyte film 40 and the air electrode 60. The reaction preventing film 50 suppresses the formation of an electric resistance layer by reacting YSZ contained in the solid electrolyte film 40 and Sr contained in the air electrode 60. The reaction preventing film 50 can be made of, for example, GDC (gadolinium doped ceria). The thickness of the reaction preventing film 50 can be 3 to 50 μm.

  The air electrode 60 is disposed on the reaction preventing film 50. The air electrode 60 is made of a porous material having electronic conductivity. The air electrode 60 can be composed of, for example, LSCF (lanthanum strontium cobalt ferrite), LSF (lanthanum strontium ferrite), LNF (lanthanum nickel ferrite), LSC (lanthanum strontium cobaltite), or the like. The air electrode 60 may have a two-layer structure of a lower layer made of LSCF and an upper layer made of LSC. The thickness of the air electrode 60 can be 10-100 micrometers.

  The air electrode current collector film 70 covers the solid electrolyte film 40 and the air electrode 60. The end portion of the air electrode current collecting film 70 is connected to the interconnector 30 of another adjacent power generation element portion A. Thereby, the adjacent power generation element parts A are electrically connected in series.

  A manufacturing method of the fuel cell 100 having the above configuration is disclosed in Japanese Patent Application Laid-Open No. 2015-035418. In the present embodiment, the content of Japanese Patent Application Laid-Open No. 2015-035418 is used for the configuration and manufacturing method of the fuel cell 100.

2. Configuration of Manifold 200 The configuration of the manifold 200 will be described with reference to the drawings. FIG. 4 is a perspective view showing the configuration of the manifold 200. FIG. 5 is a cross-sectional view taken along the line QQ in FIG.

  The manifold 200 is a flat hollow body. The manifold 200 has a first main surface 210S, a second main surface 210T, and a side surface 210U, as shown in FIG. A plurality of insertion holes 201 and connection holes 202 are formed in the first main surface 210S. Each insertion hole 201 is connected to the internal space of the manifold 200. One end of each fuel cell 100 is inserted into each insertion hole 201. The connection hole 202 is connected to the internal space of the manifold 200. One end of the fuel introduction passage 300 is connected to the connection hole 202. The second main surface 210T is provided on the opposite side of the first main surface 210S. The side surface 210U is continuous with the outer edges of the first main surface 210S and the second main surface 210T.

  As illustrated in FIG. 5, the manifold 200 includes a manifold body 210 (an example of a metal member), a coating layer 220, a first intermediate layer 230, and a second intermediate layer 240.

  The manifold body 210 is formed in a plate shape. The manifold body 210 is made of a metal material containing iron and chromium. As such a metal material, stainless steel or the like is suitable. It is preferable that the thermal expansion coefficient of the manifold main body 210 approximate the thermal expansion coefficient of the fuel cell 100.

  The manifold body 210 may contain Ti (titanium) or Al (aluminum) in addition to iron and chromium.

  In this embodiment, since the manifold body 210 is in contact with the second intermediate layer 240 containing aluminum, it is preferable that the manifold body 210 also contains aluminum. Thereby, the adhesiveness of the manifold main body 210 and the 2nd intermediate | middle layer 240 can be improved more. The manifold body 210 may contain aluminum as aluminum oxide (alumina). The average concentration of aluminum in the manifold body 210 is 0.01 at. % Or more and 6.5 at. % Or less.

  Further, when the manifold 200 does not include the second intermediate layer 240, the manifold main body 210 comes into contact with the first intermediate layer 230 containing titanium. Therefore, the manifold main body 210 preferably contains titanium. . Thereby, the adhesiveness of the manifold main body 210 and the 1st intermediate | middle layer 230 can be improved more. The manifold body 210 may contain titanium as titanium oxide (titania). The average titanium concentration in the manifold body 210 is 0.01 at. % Or more and 1.0 at. % Or less.

  The coating layer 220 covers at least a part of the outer surface of the manifold body 210. The coating layer 220 preferably covers the entire area of the outer surface of the manifold body 210 that may come into contact with the oxygen-containing gas. In the present embodiment, since the first main surface 210S, the second main surface 210T, and the side surface 210U of the manifold body 210 are in contact with the oxygen-containing gas, the coating layer 220 covers the entire surface.

The coating layer 220 contains an insulating ceramic material as a main component. Examples of such a ceramic material include crystallized glass, alumina, silica, zirconia, and the like, and crystallized glass is particularly preferable. The crystallized glass, for _example, can be used SiO 2 _-B 2 _{O 3} based _glass, SiO 2 -CaO-based _glass, SiO 2 -BaO-based glass, the _MgO-B 2 _{O 3} based glass, in particular SiO ₂ - MgO-based glass is preferred. The coating layer 220 may contain titanium oxide.

  In the present embodiment, “contains the predetermined component X as a main component” means that the content of the predetermined component X is the highest on the basis of the atomic number% in each layer or each region.

  In the present embodiment, the “crystallized glass” means that the volume ratio of the crystal phase to the total volume (that is, the crystallinity) is 60% or more, and the volume occupied by the amorphous phase and impurities with respect to the total volume It means glass (ceramics) with a ratio of less than 40%. The degree of crystallinity of crystallized glass can be obtained by calculating the volume ratio of the crystal phase region from the glass structure and composition distribution after crystallization. The glass structure and composition distribution after crystallization are identified by using, for example, an XRD (X-ray diffractometer) to identify a crystal phase, SEM (scanning electron microscope) and EDS (energy dispersive X-ray spectrometer), or It can be observed by SEM and EPMA (Electron Probe Microanalyzer).

  The coating layer 220 is preferably dense. The porosity in the coating layer 220 is preferably less than 10%. The average diameter of the pores present in the coating layer 220 can be 0.1 to 10 μm. The thickness of the coating layer 220 can be 5 μm or more and 200 μm or less.

  In the present embodiment, the “average concentration of a predetermined element” contained in each layer or region means an average concentration obtained by line analysis based on an atomic concentration profile, that is, comparison of characteristic X-ray intensities by EDS. Specifically, in a cross section perpendicular to the first main surface 210S of the manifold main body 210, each layer or each region along the thickness direction perpendicular to the first main surface 210S is subjected to line analysis by EDS. The average density can be calculated based on the density distribution data.

  The first intermediate layer 230 is disposed between the manifold body 210 and the coating layer 220. In the present embodiment, since the manifold 200 includes the second intermediate layer 240, the first intermediate layer 230 is sandwiched between the second intermediate layer 240 and the coating layer 220. The thickness of the first intermediate layer 230 is not particularly limited, but may be 0.5 μm or more and 25 μm or less.

  The first intermediate layer 230 contains an insulating ceramic material as a main component. As such a ceramic material, the same material as the coating layer 220 can be used. The ceramic material of the first intermediate layer 230 may be different from the ceramic material of the coating layer 220, but is preferably the same type.

  The first intermediate layer 230 contains titanium oxide. The average concentration of titanium in the first intermediate layer 230 is 0.5 at. % Or more 25.0 at. % Or less. The average concentration of titanium in the first intermediate layer 230 is higher than the average concentration of titanium in the coating layer 220 and higher than the average concentration of titanium in the second intermediate layer 240 described later.

  The average concentration of titanium is measured by line analysis using EDS. The average titanium concentration is obtained by measuring the titanium concentration at 10 locations uniformly in the thickness direction and arithmetically averaging the measured values.

  Titanium oxide contained in the first intermediate layer 230 has higher adhesion to the manifold body 210 than the ceramic material that is the main component of the coating layer 220. In addition, since titanium oxide is a stable oxide with a high affinity for oxygen, it has high adhesion to the coating layer 220 made of a ceramic material. Therefore, even when the manifold 200 does not include the second intermediate layer 240, the coating layer 220 is removed from the manifold body 210 by inserting the first intermediate layer 230 between the coating layer 220 and the manifold body 210. It can suppress peeling.

  In the present embodiment, the interface P1 between the first intermediate layer 230 and the coating layer 220 has an average titanium concentration of 0.5 at. It is defined by the line that is%. The interface P2 between the first intermediate layer 230 and the second intermediate layer 240 is defined by a line where the concentration ratio of aluminum and titanium is 1.0.

  The first intermediate layer 230 may contain aluminum oxide. The average concentration of aluminum in the first intermediate layer 230 is preferably lower than the average concentration of aluminum in the second intermediate layer 240 described later. The average concentration of aluminum in the first intermediate layer 230 is 0.1 at. % Or more 20.0 at. % Or less.

  In the present embodiment, since the first intermediate layer 230 is in contact with the second intermediate layer 240 containing aluminum oxide, the first intermediate layer 230 and the second intermediate layer 230 are added to the first intermediate layer 230 by containing aluminum oxide. The adhesion of the intermediate layer 240 can be further improved.

  The second intermediate layer 240 is disposed between the manifold body 210 and the first intermediate layer 230. The thickness of the second intermediate layer 240 is not particularly limited, but can be 0.5 μm or more and 20 μm or less. The second intermediate layer 240 contains an insulating ceramic material as a main component. As such a ceramic material, the same material as that of the coating layer 220 and the first intermediate layer 230 can be used. The ceramic material of the second intermediate layer 240 may be different from the ceramic material of the coating layer 220 and the first intermediate layer 230, but is preferably the same type.

  The second intermediate layer 240 contains aluminum oxide. The average concentration of aluminum in the second intermediate layer 240 is 0.5 at. % Or more 35.0 at. % Or less. Thereby, adhesiveness can be improved. The average aluminum concentration in the second intermediate layer 240 is higher than the average aluminum concentration in the first intermediate layer 230.

  The average concentration of aluminum is measured by line analysis using EDS. The average concentration of aluminum is obtained by measuring the aluminum concentration at 10 locations equally in the thickness direction and arithmetically averaging the measured values.

  The aluminum oxide contained in the second intermediate layer 240 has higher adhesion to the manifold body 210 than the ceramic material that is the main component of the coating layer 220. In addition, since aluminum oxide is a stable oxide with high affinity for oxygen, it has high adhesion to the first intermediate layer 230 containing a ceramic material as a main component. Therefore, it is possible to further suppress the coating layer 220 from being peeled off from the manifold body 210 by inserting the second intermediate layer 240 between the manifold body 210 and the first intermediate layer 230 as in the present embodiment.

  In the present embodiment, the interface P3 between the second intermediate layer 240 and the manifold body 210 has an average aluminum concentration of 0.5 at. It is defined by the line that is%.

  The second intermediate layer 240 may contain titanium oxide. The average titanium concentration in the second intermediate layer 240 is preferably lower than the average titanium concentration in the first intermediate layer 230. The average concentration of titanium in the second intermediate layer 240 is 0.1 at. % Or more 20.0 at. % Or less.

  In the present embodiment, since the second intermediate layer 240 is in contact with the first intermediate layer 230 containing titanium oxide, the first intermediate layer 230 and the second intermediate layer 240 are also added to the second intermediate layer 240 by containing titanium oxide. The adhesion of the two intermediate layers 240 can be further improved.

(Manufacturing method of fuel cell stack 1)
A method for manufacturing the fuel cell stack 1 will be described.

  First, a predetermined number of fuel cells 100 and a manifold body 210 are prepared.

  Next, an insulating ceramic material to which aluminum is added, various coating materials (for example, amorphous glass), a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol are mixed to form the second intermediate layer 240. Make a paste.

  Next, a paste for the second intermediate layer 240 is applied so as to cover the outer surface of the manifold body 210 by a printing method, a dipping method, or the like.

  Next, an insulating ceramic material to which titanium is added, various coating materials (for example, amorphous glass), a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol are mixed to form the first intermediate layer 230. Make a paste.

  Next, the paste for the first intermediate layer 230 is applied on the paste for the second intermediate layer 240 by a printing method, a dipping method, or the like.

  Next, a paste for the coating layer 220 is prepared by mixing an insulating ceramic material and various coating materials (for example, amorphous glass), a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol.

  Next, the paste for the coating layer 220 is applied on the paste for the first intermediate layer 230 by a printing method, a dipping method, or the like.

  Next, one end of each of the plurality of fuel cells 100 is inserted into each of the plurality of insertion holes 201 of the manifold body 210 using a predetermined jig.

  Next, a gap between each insertion hole 201 and each fuel cell 100 is filled with a paste of an amorphous material (for example, amorphous glass).

  Next, heat treatment (800 ° C. to 1050 ° C., 1 hour to 10 hours) is applied to each paste that has been applied or filled. In the case where the ceramic material is an amorphous material, when the temperature of the amorphous material reaches the crystallization temperature by heat treatment and a crystal phase is generated inside and the crystallization proceeds, the amorphous material is solidified and It becomes ceramic and becomes crystallized glass.

(Other embodiments)
The present invention is not limited to the above embodiment, and various modifications or changes can be made without departing from the scope of the present invention.

  The manifold 200 has the plurality of insertion holes 201 for inserting the plurality of fuel cells 100, but may have one insertion hole 201 for inserting all of the plurality of fuel cells 100.

  Although one fuel cell 100 is inserted into each insertion hole 201 of the manifold 200, two or more fuel cells 100 may be inserted.

  Although the fuel cell 100 is inserted into the insertion hole 201 of the manifold 200, the fuel cell 100 may be disposed near the insertion hole 201 and the gap between the insertion hole 201 and the fuel cell 100 may be filled with a bonding material.

  Although the manifold 200 is formed in a flat plate shape, the outer shape of the manifold 200 is not particularly limited.

  Although the first intermediate layer 230 is continuously inserted in the entire region between the manifold body 210 and the coating layer 220, the first intermediate layer 230 may be intermittently or partially inserted. . Even in this case, peeling of the coating layer 220 from the manifold body 210 can be suppressed.

  Although the second intermediate layer 240 is interposed between the manifold body 210 and the first intermediate layer 230, the second intermediate layer 240 may not be interposed. Even in this case, as described above, the first intermediate layer 230 containing titanium oxide has high adhesion to the coating layer 220 and the manifold main body 210, so that the coating layer 220 is prevented from peeling off from the manifold main body 210. it can.

  The coating layer 220 covers at least a part of the outer surface of the manifold body 210, but may also cover the inner surface of the manifold body 210. In this case, the first intermediate layer 230 and the second intermediate layer 240 may be interposed between the coating layer 220 covering the inner surface and the manifold body 210.

  In the above embodiment, the case where the “laminate” according to the present invention is applied to a manifold for a fuel cell stack has been described, but the present invention is not limited to this. The “laminate” according to the present invention includes at least a metal member containing iron and chromium, a coating layer covering an outer surface of the metal member, and a first intermediate layer containing titanium oxide. Such a “laminated body” can be applied to components (for example, gas pipes and joints) of electrochemical devices used in a high temperature environment. Electrochemical devices include devices comprising electrochemical cells such as storage cells, photocatalysts, and electrochemical sensors in addition to fuel cells.

  Examples of the laminate according to the present invention will be described below, but the present invention is not limited to the examples described below.

(Production of Examples 1 to 20)
Examples 1 to 20 were produced as follows.

  First, a manifold body made of stainless steel (SUS430 or SUS436L) containing iron and chromium was prepared. SUS430 does not substantially contain titanium, and SUS436L contains titanium.

Next, the ceramic material of Table 1 to which titanium was added and various coating materials (SiO ₂ —CaO glass and SiO ₂ —MgO glass), a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol were mixed. A paste for one intermediate layer was prepared. At this time, as shown in Table 1, the amount of titanium added was adjusted so that the average concentration of titanium in the first intermediate layer was different for each sample.

  Next, the paste for the first intermediate layer was applied by a printing method so as to cover the outer surface of the manifold body.

Next, a paste for a coating layer is prepared by mixing the ceramic material of Table 1 with various coating materials (SiO ₂ —CaO glass and SiO ₂ —MgO glass), a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol. Was made.

  Next, the coating layer paste was applied by a printing method so as to cover the first intermediate layer paste.

  Next, each applied paste was subjected to heat treatment (850 ° C., 2 hours).

(Production of Examples 21 to 36)
Examples 21 to 36 were produced as follows.

  First, a stainless steel (SUS436L) manifold body containing iron and chromium was prepared.

  Next, a paste for the second intermediate layer was prepared by mixing the ceramic material of Table 1 to which aluminum was added, various coating materials, a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol. At this time, as shown in Table 1, the amount of aluminum added was adjusted so that the average concentration of aluminum in the second intermediate layer was different for each sample.

  Next, the paste for the second intermediate layer was applied by a printing method so as to cover the outer surface of the manifold body.

  Next, a paste for the first intermediate layer was prepared by mixing the ceramic material of Table 1 to which titanium was added, various coating materials, a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol. At this time, as shown in Table 1, the amount of titanium added was adjusted so that the average concentration of titanium in the first intermediate layer was different for each sample.

  Next, the first intermediate layer paste was applied by a printing method so as to cover the second intermediate layer paste.

  Next, a paste for a coating layer was prepared by mixing the ceramic material of Table 1 with various coating materials, a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol.

  Next, the coating layer paste was applied by a printing method so as to cover the first intermediate layer paste.

  Next, each applied paste was subjected to heat treatment (850 ° C., 2 hours).

(Production of Comparative Examples 1 to 4)
Comparative Examples 1 to 4 were produced as follows.

  First, a stainless steel (SUS436L) manifold body containing iron and chromium was prepared.

  Next, a paste for a coating layer was prepared by mixing the ceramic material of Table 1 with various coating materials, a binder such as ethyl cellulose, and a dispersion medium such as isopropyl alcohol.

  Next, the paste for the coating layer was applied by a printing method so as to cover the outer surface of the manifold body.

  Next, the applied paste for the coating layer was subjected to heat treatment (850 ° C., 2 hours).

(Concentration analysis of elements in the first intermediate layer and the second intermediate layer)
Examples 1 to 36 were cut in parallel to the thickness direction, and line analysis was performed by EDS along the thickness direction to obtain concentration distribution data of titanium and aluminum in the thickness direction. Based on the concentration distribution data, the average concentration of titanium in the first intermediate layer and the average concentration of aluminum in the second intermediate layer were calculated. The calculation results are shown in Table 1.

(Thermal durability test)
A thermal durability test was carried out on each of Examples 1 to 36 and Comparative Examples 1 to 4 simulating an actual use environment. Specifically, using the coated manifold, heat treatment in which heating and cooling were repeated at temperatures of 850 ° C. × 30 min and 100 ° C. × 30 min in the atmosphere was repeated 20 times. Thereafter, the manifold was held in a furnace heated to 850 ° C. for 1000 hours, and then heat treatment was repeated 20 times, repeating heating and cooling to temperatures of 850 ° C. × 30 min and 100 ° C. × 30 min. In Table 1, the case where no peeling was observed in the coating layer after the heat treatment was evaluated as “「 (excellent) ”, and the case where micro-peeling (peeling of 200 μm or less) was observed was designated as“ Good ” Evaluation was made and the case where peeling exceeding 200 μm occurred was evaluated as “× (impossible)”. Here, the size of the peeled portion was defined by the equivalent circle diameter of the pores generated by the peeling.

  As shown in Table 1, Examples 1 to 20 provided with a first intermediate layer containing titanium oxide, and Examples provided with a first intermediate layer containing titanium oxide and a second intermediate layer containing aluminum oxide In 21-36, it was able to suppress that a coating layer peeled from the manifold main body compared with Comparative Examples 1-4. This is because the first intermediate layer and the second intermediate layer have high adhesion to the coating layer and the manifold body, respectively.

  Moreover, in Examples 5-36 using the manifold main body containing titanium, it has confirmed that peeling of a coating layer could be suppressed more. This is because the adhesiveness between the first intermediate layer and the manifold body can be further improved by incorporating titanium contained in the first intermediate layer into the manifold body.

  The average concentration of titanium in the first intermediate layer is 0.5 at. % Or more 25.0 at. % In Examples 5 to 16, the average concentration of titanium was 0.5 at. % Or 25.0 at. Compared with Examples 17-20 which exceeded%, the peeling of the coating layer could be suppressed more.

  The average concentration of aluminum in the second intermediate layer is 0.5 at. % Or more 35.0 at. % In Examples 21 to 32 in which the average concentration of titanium was 0.5 at. % Or 35.0 at. Compared with Examples 33 to 36 with more than%, the peeling of the coating layer could be further suppressed.

DESCRIPTION OF SYMBOLS 1 Fuel cell stack 100 Fuel cell 200 Manifold 210 Manifold main body 201 Insertion hole 220 Coating layer 230 1st intermediate | middle layer 240 2nd intermediate | middle layer 300 Fuel introduction channel | path

Claims (6)

A metal member composed of stainless steel containing iron, chromium and titanium;
A coating layer covering at least a part of the surface of the metal member and containing an insulating ceramic material selected from SiO ₂ , MgO, BaO, and CaO as a main component;
A first intermediate layer that is disposed between the metal member and the coating layer , contains TiO _2, and contains an insulating ceramic material selected from TiO ₂ , CaO, SiO ₂ , MgO, and BaO as a main component. When,
With
The first intermediate layer is adjacent to each of the coating layer and the metal member;
The average concentration of titanium in the first intermediate layer is higher than the average concentration of titanium in the coating layer,
The average concentration of titanium in the first intermediate layer is 0.5 at. % Or more 25.0 at. % Or less,
Laminated body. A metal member composed of stainless steel containing iron, chromium and titanium,
A coating layer covering at least a part of the surface of the metal member and containing an insulating ceramic material selected from SiO ₂ , MgO, BaO, and CaO as a main component;
A first intermediate layer that is disposed between the metal member and the coating layer , contains TiO _2, and contains an insulating ceramic material selected from TiO ₂ , CaO, SiO ₂ , MgO, and BaO as a main component. When,
A second intermediate layer, which is disposed between the first intermediate layer and the metal member and mainly comprises an insulating ceramic material selected from SiO ₂ , Al ₂ O ₃ , MgO, BaO and CaO;
With
The first intermediate layer is adjacent to the coating layer;
The second intermediate layer is adjacent to each of the first intermediate layer and the metal member;
The average concentration of titanium in the first intermediate layer is higher than the average concentration of titanium in the coating layer,
The average concentration of aluminum in the second intermediate layer is higher than the average concentration of aluminum in the first intermediate layer,
The average concentration of titanium in the first intermediate layer is 0.2 at. % Or more 29.1 at. % Or less,
The average concentration of aluminum in the second intermediate layer is 0.2 at. % Or more 38.2 at. % Or less,
Laminated body. A metal member composed of stainless steel containing iron, chromium and titanium,
A coating layer covering at least a part of the surface of the metal member and containing an insulating ceramic material selected from SiO ₂ , MgO, BaO, and CaO as a main component;
A first intermediate layer that is disposed between the metal member and the coating layer , contains TiO _2, and contains an insulating ceramic material selected from TiO ₂ , CaO, SiO ₂ , MgO, and BaO as a main component. When,
A second intermediate layer, which is disposed between the first intermediate layer and the metal member and mainly comprises an insulating ceramic material selected from SiO ₂ , Al ₂ O ₃ , MgO, BaO and CaO;
With
The first intermediate layer is adjacent to the coating layer;
The second intermediate layer is adjacent to each of the first intermediate layer and the metal member;
The average concentration of titanium in the first intermediate layer is higher than the average concentration of titanium in each of the coating layer and the second intermediate layer,
The average concentration of titanium in the first intermediate layer is 0.2 at. % Or more 29.1 at. % Or less,
The average concentration of aluminum in the second intermediate layer is 0.2 at. % Or more 38.2 at. % Or less,
Laminated body. The average concentration of aluminum in the second intermediate layer is 0.5 at. % Or more 35.0 at. % Or less,
The laminate according to claim 2 or 3. The metal member contains titanium;
The laminated body in any one of Claims 1 thru | or 4. An electrochemical cell;
A laminate according to any one of claims 1 to 5,
An electrochemical device comprising: