JP5007918B2 - Gas seal part for fuel cell and manufacturing method thereof - Google Patents

Description

    The present invention relates to a gas seal component disposed between components requiring a gas seal of a fuel cell, particularly a fuel cell operated at high temperature, and a method for manufacturing the same.

  Examples of the fuel cell that operates at a high temperature include a solid oxide fuel cell including a cell plate holding a single cell, a separator plate, and a component such as a flange. In the case of such a solid oxide fuel cell, there are many components such as between the cell plate and the separator plate and between the separator plate and the flange in high and low temperature environments, and in the oxidizing and reducing properties. In an atmosphere, gas sealing properties that prevent leakage of gases such as hydrogen, natural gas, and air, and sufficient bonding strength and electrical insulation are required.

In recent years, with the improvement of the low temperature performance of solid oxide fuel cells, there is a tendency to use metal materials, such as ferritic stainless steel, for separator plates and flanges. A large tensile or compressive force is applied to the joint between the two due to thermal deformation of the metal material that occurs as the temperature rises and falls. Development of seal parts is underway.
JP 2002-203581 A

  However, in the gas seal part for a fuel cell made of the glass-based bonding material described above, although the bonding force is excellent, since the glass-based bonding material is a brittle material, the tensile force generated by the thermal deformation of the metal material can be reduced. Since the compressive force is excellent in the bonding force, it is directly applied to the glass-based bonding material, and there is a problem that the glass-based bonding material itself is cracked.

  In addition, in the gas seal part for a fuel cell described above, for example, when used for joining a separator plate and a flange, a large amount of glass is used between the two for the convenience of increasing the plane accuracy and absorbing the variation in parallelism. It is necessary to form a thick glass layer by filling the system bonding material. Thus, when a thick glass layer is formed, there is a problem that the risk of causing cracking increases, and these problems are eliminated. It has been a conventional problem to be solved.

  The present invention has been made paying attention to the above-described conventional problems. When the fuel cell is disposed between components that require gas sealing, a tensile force or a compressive force generated by thermal deformation of the components is loaded. Even if it was made, it aims at providing the gas-seal component for fuel cells which can maintain the outstanding gas-sealing property and joining property, and its manufacturing method.

A gas seal part for a fuel cell according to the present invention is a gas seal part arranged between components that require gas seal in a fuel cell, and is a coating comprising an elastic core body and a metal foil covering the core body. A coating film comprising a metal foil, and a bonding layer made of a glass-based bonding material formed on the surface of the coating film and bonded to both one component and the other component between the components When, characterized in that the difference in thermal expansion coefficient between the bonding layer made of a glass-based bonding material and ^{2 × 10 -6 (1 / K} ) or less, and a bonding layer made of a glass-based bonding material, the bonding The difference in the coefficient of thermal expansion from the component to which the layers are bonded is 2 × 10 ⁻⁶ (1 / K) or less, and the configuration of this gas seal component for a fuel cell is the conventional problem described above. As a means to solve.

  In the gas seal part for a fuel cell of the present invention, when the fuel cell gas seal part is disposed between components that require gas seal in the fuel cell, the bonding layer made of a glass-based bonding material is a coating film made of a metal foil that does not transmit gas. In addition to being formed on the surface, this bonding layer is bonded to both one component and the other component, so that excellent gas sealability and bondability between the components are ensured.

  When one component and the other component are thermally deformed and a tensile force or a compressive force is applied to the gas seal portion for the fuel cell, it has a coating film made of metal foil and elasticity. Since the core body deforms and absorbs tensile and compressive forces, there is little possibility of cracking in the bonding layer made of glass-based bonding material, and therefore excellent gas sealing and bonding properties are maintained. The Rukoto.

  According to the present invention, since it is configured as described above, it is possible to ensure excellent gas sealability and bondability between the components when arranged between the components that require gas sealing in the fuel cell. Needless to say, even if a tensile force or a compressive force generated by thermal deformation of the component parts is applied, an excellent effect is achieved in that it is possible to maintain excellent gas sealability and bondability.

  In the gas seal part for a fuel cell of the present invention, the core body having elasticity is used when the coating film is bonded to the component parts via the bonding layer while preventing the coating films made of metal foil from adhering to each other. It functions as a pressing material, and in addition, functions as a cushion material that absorbs variations in planar accuracy and parallelism of components.

  As described above, since the core body functions as a cushioning material, it is not necessary to increase the thickness of the bonding layer made of glass-based bonding material, and the coating film made of metal foil is the minimum necessary for bonding to the component parts. The thickness can be reduced to a thickness, and as a result, the concern that the bonding layer made of the glass-based bonding material breaks can be almost eliminated.

  In the gas seal part for a fuel cell of the present invention, the core body can be composed of an inorganic porous material, and from the viewpoint of production, the core body is made of a ceramic fiber assembly that is an inorganic porous material. More preferably, the non-woven fabric of ceramic fibers is preferably 0.5 to 1 mm thick.

  In the gas seal part for a fuel cell of the present invention, the coating film can be made of, for example, a stainless steel metal foil, and the thickness of the coating film at the joint portion between the component parts is economical. And from a viewpoint of durability, it is desirable to set it as 10-30 micrometers. As described above, the coating film made of the metal foil is firmly bonded to the component through the bonding layer. However, since the coating film is thin and easily deformed, the coating film flexibly follows the thermal deformation of the component. And the coating film which consists of this metal foil has the function of forming the joining interface, and the function of the partition which ensures gas tightness.

  In the gas seal part for a fuel cell according to the present invention, in a state where the gas seal part is arranged and gas-sealed between the component parts, either one of the end face located on the gas flow side and the end face located on the anti-gas flow side of the core body Adopting a configuration in which the end surface is exposed, that is, a configuration in which one of the end surface located on the gas flow side of the core body and the end surface located on the anti-gas flow side is not covered with the coating film. can do. When this configuration is employed, air does not accumulate inside the gas seal component covered with the coating film, and therefore deformation of the gas seal component due to thermal expansion of air at a high temperature can be prevented.

  In addition, in the gas seal part for a fuel cell according to the present invention, the part that functions as the partition wall of the coating film, that is, the part that does not require flexibility in the state where the gas seal is disposed between the constituent parts, that is, the thick partition wall In this case, the durability of the coating film against oxidation or the like is improved.

  Furthermore, in the gas seal part for a fuel cell of the present invention, a bonding layer formed of a glass-based bonding material that is formed on the surface of the coating film and is bonded to both one component part and the other component part between the component parts, It is strongly bonded to the coating film and the component parts, respectively, but since it is thin and easily deformed, it flexibly follows the thermal deformation of the component parts.

  At this time, if there is a large difference in the coefficient of thermal expansion between the component parts (not limited to metal materials), the bonding layer and the coating film, the interface between the bonding layer and the component parts, the bonding layer and the coating film Since cracks occur at the interface, it is necessary to make the difference in thermal expansion coefficient between the constituent materials of the component part, the bonding layer, and the coating film equal to or less than a certain value.

Specifically, the difference in coefficient of thermal expansion between the coating film made of metal foil and the bonding layer made of glass-based bonding material is set to 2 × 10 ⁻⁶ (1 / K) or less, or made of glass-based bonding material. The difference in thermal expansion coefficient between the bonding layer and the component to which the bonding layer is bonded needs to be 2 × 10 ⁻⁶ (1 / K) or less. In either case, the difference in thermal expansion coefficient is 1 It is desirable to be 5 × 10 ⁻⁶ (1 / K) or less.

  As described above, since the bonding layer made of the glass-based bonding material is thin and easily deformed, it flexibly follows the thermal deformation of the component parts, but it was a case where cracking occurred beyond the limit that could be followed. Even so, the crack direction is local to the layer thickness of the bonding layer and is local, so that there is almost no significant influence on the bonding force and gas sealing performance.

  In this case, even if the material of the component part is a metal material such as stainless steel, the fuel cell gas seal part has a bonding layer made of a glass-based bonding material with excellent electrical insulation on the surface. In addition, electrical insulation between the components to be joined can be ensured, and by setting the thickness of the joining layer to 10 to 50 μm, sufficient joining force and insulation can be secured.

The glass-based bonding material used for the bonding layer can be selected within the range of the above-mentioned coefficient of thermal expansion. However, when the component and the metal foil of the coating film are ferritic stainless steel, the above-described thermal expansion is performed. It is possible to select and use barium oxide, alumina, silica, and calcia glass as the glass contained within the range of the rate, specifically, 52% BaO-3% Al ₂ O ₃ -33SiO. _{2 -12% CaO, 42% BaO} -Al 2 O 3 -35SiO 2 -9% CaO-B 2 O 3 -ZnO-PbO-V 2 O 5, 43% BaO-Al 2 O 3 -35SiO 2 -9% CaO—B ₂ O ₃ —PbO—V ₂ O ₅ can be selected and used.

As a preferred embodiment of the gas seal part for a fuel cell of the present invention, the core body is an alumina fiber non-woven fabric (thickness 0.5 to 1 mm) which is an inorganic porous material, and the coating film covering the core body is made of stainless steel. It is possible to adopt a configuration in which a foil (thickness 20 to 50 μm) is used, and a bonding layer formed on the surface of the coating film is BaO—Al ₂ O ₃ —SiO ₂ —CaO glass (thickness 10 to 50 μm).

  When manufacturing the gas seal part for a fuel cell of the present invention described above, as shown in FIG. 17, after forming an elastic core body and then covering the core body with a coating film made of a metal foil. The glass-based bonding material may be sprayed onto the surface of the coating film using a spray or the like, followed by baking to form a bonding layer made of the glass-based bonding material.

  In manufacturing a fuel cell in which the fuel cell gas seal component manufactured in this way is arranged between components that require gas sealing, for example, a cell plate that is a component holding a single cell and When manufacturing a fuel cell having a separator plate which is a component, as shown in FIG. 18, each joint surface of the cell plate and the separator plate is degreased, and then between these cell plates and the separator plate. Then, after arranging the fuel cell gas seal parts and laminating each other, it is possible to adopt a configuration in which baking is performed while applying a load in the laminating direction.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

[Example 1]
1 to 3 show one embodiment of a gas seal part for a fuel cell according to the present invention. As shown in FIG. 2, the gas seal part 1 for a fuel cell has a ring shape as a whole. As shown in FIG. 1, an elastic core body 2, a coating film 3 made of a metal foil covering the core body 2, and a surface of the coating film 3 formed between the component parts S1 and S2 It has a bonding layer 4 made of a glass-based bonding material that is bonded to both the one component S1 and the other component S2.

In this embodiment, the core body 2 is an alumina-silica fiber nonwoven fabric (thickness 1 mm), which is an inorganic porous material, and the coating film 3 covering the core body 2 is a ferritic stainless steel foil (SUS430: thickness 30 μm), The bonding layer 4 formed on the surface of the coating film 3 was 52% BaO-3% Al ₂ O ₃ -33SiO ₂ -12% CaO-based glass (thickness 30 μm).

  In producing the fuel cell gas seal part 1, first, a glass slurry was prepared together with butyl acetate as an ethylcellulose solvent using a glass powder having a particle size of about 10 μm as a binder. Subsequently, the glass slurry was spray-coated on one surface of the ferritic stainless steel foil, followed by heat treatment at 900 ° C. for 15 minutes in the atmosphere to form a bonding layer 4 having a thickness of 30 μm on the surface of the ferritic stainless steel foil. . Thereafter, the coating film 3, which is a ferritic stainless steel foil on which the bonding layer 4 is formed, is coated on the core body 2, which is a nonwoven fabric of alumina-silica fibers, with the glass coating surface facing outside, and the ends are pressure-bonded. I let you.

  Ferrite stainless steel (SUS430) plate having a plate thickness of 4 mm is used for the component parts S1 and S2 to be joined by the fuel cell gas seal part 1 described above, and one of the component parts S1 penetrates in the center. It shall have hole S1a.

Therefore, the fuel cell gas seal part 1 described above is sandwiched between the component parts S1 and S2, and heated at 900 ° C. for 15 minutes in the atmosphere while applying a load of 300 g / cm ² , and the ^two component parts S1 and S2 are heated. A test piece was fabricated by joining S2.

  As shown in FIG. 3, a through hole S1a is formed between the upper cylinder 10 to which hydrogen gas is supplied and the upper and lower cylinders 10 and 11 of the hydrogen permeation test including the lower cylinder 11 having the hydrogen detector 12. A test piece is set in a state where one component S1 having the upper side is positioned upward, and hydrogen gas is supplied to the upper cylinder 10 side in each environment at room temperature and 700 ° C., and a hydrogen detector in the lower cylinder 11 12, a test for detecting permeation (leakage) of hydrogen gas was conducted. As a result, hydrogen permeation was not detected in both the room temperature and 700 ° C. environments. Further, even after this test was repeated 50 times, there was no hydrogen permeation, and no cracking occurred in the bonding layer 4 made of the glass-based bonding material.

  As described above, in the gas seal part 1 for a fuel cell described above, the coating layer 3 made of a metal foil that does not transmit gas when the bonding layer 4 made of the glass-based bonding material is disposed between the component parts S1 and S2. In addition, since this bonding layer 4 is bonded to both the one component S1 and the other component S2, excellent gas sealing properties and bondability between the component S1 and S2 are ensured. Will be.

  And even if it is a case where thermal deformation occurs in one component S1 and the other component S2 and a tensile force or a compressive force is applied to the joint portion, as shown in FIG. Since both the coating film 3 made of metal foil and the elastic core body 2 are deformed to absorb the tensile force and the compressive force, there is little possibility that the bonding layer 4 made of the glass-based bonding material is cracked. Therefore, excellent gas sealability and bondability are maintained.

[Example 2]
In the gas seal part 1 for a fuel cell according to another embodiment of the present invention, the glass slurry is spray-coated on one side of the ferritic stainless steel foil and then heat-treated at 350 ° C. for 15 minutes in the atmosphere. The van inda is burned out, and the other configuration is the same as that of the fuel cell gas seal component 1 according to the previous embodiment.

  Also in this example, the same test piece as in the previous example was manufactured and the same test was performed the same number of times using the hydrogen permeation test. As a result, hydrogen permeation was observed at both room temperature and 700 ° C. No cracks occurred in the bonding layer 4 made of the glass-based bonding material.

[Example 3]
FIG. 4 shows a fuel cell gas seal component 21 according to still another embodiment of the present invention. The fuel cell gas seal component 21 in this embodiment is the fuel cell gas seal component 1 according to the previous embodiment. The difference is that the end face 2a located on the anti-gas flow side (left side in the figure) of the two cores is exposed in a state where the gas is sealed between the component parts S1 and S2. Is the same as that of the gas seal part 1 for a fuel cell according to the previous embodiment.

  In the production of the fuel cell gas seal component 21, the coating film 3 which is a ferritic stainless steel foil having the bonding layer 4 formed thereon is a non-woven fabric of alumina-silica fibers with the glass coating surface facing outside. The core body 2 was covered and the end portion was partially crimped.

  Also in this example, the same test piece as in the previous example was manufactured and the same test was performed the same number of times using the hydrogen permeation test. As a result, hydrogen permeation was observed at both room temperature and 700 ° C. No cracks occurred in the bonding layer 4 made of the glass-based bonding material.

  Also in the fuel cell gas seal component 21 in this embodiment, when it is disposed between the component parts S1 and S2, excellent gas sealability and bondability are ensured, and one of the component parts S1 and the other component part S2 is secured. Even when thermal deformation occurs and a tensile force or compressive force is applied to the joint portion, excellent gas sealability and bondability will be maintained. Since air does not accumulate inside the broken gas seal component 21, deformation of the gas seal component 21 itself due to thermal expansion of air at a high temperature can be prevented.

[Example 4]
FIGS. 5 and 6 show a fuel cell gas seal component 31 according to still another embodiment of the present invention. As shown in FIG. The difference from the fuel cell gas seal component 21 according to the embodiment is that it functions as a partition wall of the coating film 3 by covering the end surface 2b located on the opposite side (right side in the drawing) to the exposed end surface 2a of the two cores. The portion, that is, the portion where flexibility is not required is the thick partition wall portion 3a (the partition wall portion 3a having a thickness of 1 mm), and the other configuration and manufacturing method are the gas seal parts for fuel cells according to the previous embodiment. 21.

  In the fuel cell gas seal component 31, as shown in FIG. 6, the thick partition wall portion 3a of the coating film 3 is positioned between the component components S1 and S2 in a state where the gas seal is formed between the component components S1 and S2. In this case, the durability of the coating film 3 against oxidation or the like is improved.

  Also in this example, the same test piece as in the previous example was manufactured and the same test was performed the same number of times using the hydrogen permeation test. As a result, hydrogen permeation was observed at both room temperature and 700 ° C. No cracks occurred in the bonding layer 4 made of the glass-based bonding material.

[Example 5]
7 and 8 show a fuel cell gas seal component 41 according to still another embodiment of the present invention. As shown in FIG. 7, the fuel cell gas seal component 41 in this embodiment has a rectangular frame shape as a whole, and the configuration and manufacturing method are the same as those of the fuel cell gas seal component 1 according to the previous embodiment. is there.

  In this embodiment, as shown in FIG. 8, a rectangular cell plate made of ferritic stainless steel (SUS430) and a separator plate are used as component parts S1 and S2, and the fuel cell described above is provided between these component parts S1 and S2. The gas seal part 41 for the fuel cell was joined so as to be sandwiched, and the component parts S1 and S2 and the gas seal part 41 for the fuel cell were laminated in 15 stages to produce a stack structure. At this time, the components S1, S2, and 41 were all bonded in the same manner as in Example 1.

  Therefore, in each environment at room temperature and 700 ° C., hydrogen gas and air are supplied from the hydrogen gas supply hole Ha and the air supply hole Oa formed in the stack structure, respectively, and the hydrogen gas discharge hole Hb and the air discharge hole Ob. A hydrogen permeation test was conducted in which hydrogen gas and air were respectively discharged from the gas and hydrogen gas in the discharged air was detected with a hydrogen detector. As a result, the permeation of hydrogen gas was not detected in both the room temperature and 700 ° C. environments. Further, even after this test was repeated 50 times, there was no permeation of hydrogen gas, and no cracking occurred in the bonding layer 4 made of the glass-based bonding material.

[Example 6]
9 and 10 show a gas seal part 51 for a fuel cell according to still another embodiment of the present invention. As shown in FIG. 9, the fuel cell gas seal component 51 in this embodiment has a disk shape as a whole, and the configuration and manufacturing method are the same as those of the fuel cell gas seal component 1 according to the previous embodiment. .

  In this embodiment, as shown in FIG. 10, a cell plate and a separator plate made of ferritic stainless steel (SUS430) having a disk shape are used as component parts S1 and S2, and the fuel cell described above is provided between these component parts S1 and S2. The gas seal parts 51 for the fuel cell were joined so as to be sandwiched, and the component parts S1 and S2 and the gas seal part 51 for the fuel cell were laminated in 15 stages to produce a stack structure. At this time, the components S1, S2, and 51 were bonded in the same manner as in Example 1.

  Therefore, in each environment at room temperature and 700 ° C., hydrogen gas is supplied from the hydrogen gas supply hole Ha formed in the stack structure, and hydrogen gas is discharged from the hydrogen gas discharge hole Hb. A hydrogen permeation test was performed to detect hydrogen gas in the exhausted air that passed between S1 and S2. As a result, the permeation of hydrogen gas was not detected in both the room temperature and 700 ° C. environments. Further, even after this test was repeated 50 times, there was no permeation of hydrogen gas, and no cracking occurred in the bonding layer 4 made of the glass-based bonding material.

[Example 7]
11 to 13 show a fuel cell gas seal part 61 according to still another embodiment of the present invention. As shown in FIG. 11, the fuel cell gas seal component 61 in this embodiment has a rectangular frame shape as a whole, and the core body 2 is made of an alumina-silica fiber non-woven fabric (thickness 0. The other configuration and manufacturing method except that the thickness is 5 mm) are the same as those of the fuel cell gas seal component 1 according to the previous embodiment.

In this embodiment, as shown in FIGS. 12 and 13, a rectangular cell plate made of ferritic stainless steel (SUS430) is used as a component S1, and a fuel electrode substrate S2a, an electrolyte layer S2b (YSZ film), and an air electrode. The flat fuel electrode supporting cell formed by laminating the layer S2c is used as the component S2, and the cell plate (component S1) and the electrolyte layer S2b (component S2) of the fuel electrode supporting cell are arranged as described above. The fuel cell gas seal component 61 was sandwiched and heated at 900 ° C. for 15 minutes in the atmosphere while applying a load of 300 g / cm ² to produce a test piece. At this time, the difference in thermal expansion coefficient between the cell plate (component S1) and the electrolyte layer S2b (component S2) of the fuel electrode supporting cell was set to 0.5 × 10 ⁻⁶ (1 / K) or less.

  And when this test piece was subjected to the same test as the previous example using the hydrogen permeation test described above, the hydrogen did not permeate in any environment of room temperature and 700 ° C., and glass The bonding layer 4 made of the system bonding material did not crack at all.

[Example 8]
14 to 16 show a fuel cell gas seal component 71 according to still another embodiment of the present invention. As shown in FIG. 14, the fuel cell gas seal component 71 in this embodiment has a circular shape as a whole, and the other configuration and manufacturing method are the same as those of the fuel cell gas seal component 1 according to the previous embodiment. It is.

In this embodiment, as shown in FIGS. 15 and 16, a cell plate made of ferritic stainless steel (SUS430) having a tubular shape is used as a component S1, and a fuel electrode substrate S2a, an electrolyte layer S2b (YSZ film), and an air electrode layer. The cylindrical fuel electrode supporting cell formed by laminating S2c is used as the component S2, and the above-mentioned is provided between the cell plate (component S1) and the electrolyte layer S2b (component S2) of the fuel electrode supporting cell. The fuel cell gas seal component 71 was sandwiched and heated at 900 ° C. for 15 minutes in the atmosphere while applying a load of 300 g / cm ² to join the components S1 and S2. At this time, the difference in thermal expansion coefficient between the cell plate and the electrolyte layer S2b of the fuel electrode supporting cell was set to 0.5 × 10 ⁻⁶ (1 / K) or less.

  Therefore, in each environment at room temperature and 700 ° C., hydrogen gas is supplied to the inside of the cylindrical electrode support cell S2 where the fuel electrode substrate S2a is located, and hydrogen is transmitted to the outside where the air electrode layer S2c is located. A hydrogen permeation test for detecting gas was performed. As a result, the permeation of hydrogen gas was not detected in both the room temperature and 700 ° C. environments. Further, even after this test was repeated 50 times, there was no permeation of hydrogen gas, and no cracking occurred in the bonding layer 4 made of the glass-based bonding material.

[Comparative Example 1]
Therefore, the same form as in Example 3 is used, and the core body is made of an inorganic porous material alumina-silica fiber non-woven fabric (thickness 1 mm), and the coating film covering the core body is nickel foil (thickness 30 μm). And a gas seal component for a fuel cell of Comparative Example 1 in which the bonding layer formed on the surface of the coating film is 52% BaO-3% Al ₂ O ₃ -33SiO ₂ -12% CaO-based glass (thickness 30 μm). This was produced in the same manner as in Example 3.

  The same test was performed on the fuel cell gas seal part of Comparative Example 1 using the above-described hydrogen permeation test, and no hydrogen permeation was observed at any of room temperature and 700 ° C. After repeating this test five times, hydrogen permeation occurred and cracks occurred in the bonding layer made of the glass-based bonding material, although only slightly.

In Comparative Example 1, the difference in thermal expansion coefficient between the nickel foil used for the coating film and the glass-based bonding material used for the bonding layer was 1.5 × 10 ⁻⁶ [1 / K] or more. Specifically, since it was about 3.5 × 10 ⁻⁶ [1 / K], it is considered that the bonding layer made of the glass-based bonding material was cracked. Therefore, the coating film made of metal foil, The difference in coefficient of thermal expansion from the bonding layer made of the glass-based bonding material is set to 2 × 10 ⁻⁶ (1 / K) or less, preferably 1.5 × 10 ⁻⁶ (1 / K) or less. Thus, it was proved that a durable gas sealing property was obtained.

[Comparative Example 2]
Further, the core body is made of an alumina-silica fiber non-woven fabric (thickness: 1 mm), which is an inorganic porous material, and the coating film covering the core body is made of a ferritic stainless steel foil (SUS430). : the thickness 30 [mu] m), a fuel cell of Comparative example 2, the bonding layer _{52% BaO-3% Al 2} O 3 -33SiO 2 -12% CaO -based glass formed on the surface of the coating film (thickness 60 [mu] m) A gas seal part was produced in the same manner as in Example 3.

  The same test was performed on the fuel cell gas seal part of Comparative Example 2 using the above-described hydrogen permeation test. However, no hydrogen permeation was observed at both room temperature and 700 ° C. After repeating this test twice, hydrogen permeation occurred and cracks in the layer thickness direction occurred in the bonding layer made of the glass-based bonding material.

  In Comparative Example 2, since the thickness of the bonding layer made of the glass-based bonding material was 60 μm, it is considered that cracking occurred in the layer thickness direction. Therefore, if the thickness of the bonding layer is 10 to 50 μm In addition, it was proved that a durable gas sealing property can be obtained while ensuring a sufficient bonding force and insulation.

[Comparative Example 3]
Furthermore, it has the same form as that of Example 3, and the core body is made of an inorganic porous material alumina-silica fiber nonwoven fabric (thickness 1 mm), and the coating film covering the core body is made of a ferritic stainless steel foil (SUS430). : 30 μm), and the joining layer formed on the surface of this coating film is 52% BaO-3% Al ₂ O ₃ -33SiO ₂ -12% CaO-based glass (thickness less than 10 μm). A gas seal part for the production was produced in the same manner as in Example 3.

  When the same test was performed using the hydrogen permeation test described above for the fuel cell gas seal part of Comparative Example 3, hydrogen permeation occurred at both room temperature and 700 ° C., A bonding layer made of a glass-based bonding material was partially missing, and electrical insulation was insufficient.

  In Comparative Example 3, it was considered that the thickness of the bonding layer made of the glass-based bonding material was less than 10 μm, so it was considered that the bonding layer was thinned locally. When the thickness is 50 μm, it has been proved that a durable gas sealing property can be obtained while ensuring a sufficient bonding force and insulation.

[Comparative Example 4]
Furthermore, the same form as in Example 3 is used, and the core body is a non-woven fabric of alumina-silica fibers (thickness 1 mm), which is an inorganic porous material. The coating film covering the core body is made of a ferritic stainless steel foil ( SUS430: 50 μm thick), and the bonding layer formed on the surface of the coating film is 52% BaO-3% Al ₂ O ₃ -33SiO ₂ -12% CaO-based glass (thickness 30 μm). A gas seal part for the production was produced in the same manner as in Example 3.

  The same test was performed on the fuel cell gas seal part of Comparative Example 4 using the hydrogen permeation test described above, but there was no permeation of hydrogen at both room temperature and 700 ° C. After repeating this test five times, hydrogen permeation occurred and cracks in the layer thickness direction occurred in the bonding layer made of the glass-based bonding material.

  In Comparative Example 4, since the thickness of the coating film made of the ferritic stainless steel foil was 50 μm, it was considered that the flexibility as the foil was lowered and the rigidity of the coating film was increased. If the thickness is set to 10 to 30 μm, it is possible to flexibly follow the thermal deformation of the component parts, and it was proved that a durable gas sealing property can be obtained.

[Comparative Example 5]
Furthermore, the same form as in Example 3 is used, and the core body is a non-woven fabric of alumina-silica fibers (thickness 1 mm), which is an inorganic porous material. The coating film covering the core body is made of a ferritic stainless steel foil ( SUS430: a thickness of less than 10 μm), and the bonding layer formed on the surface of the coating film is 52% BaO-3% Al ₂ O ₃ -33SiO ₂ -12% CaO-based glass (thickness 30 μm). A battery gas seal part was produced in the same manner as in Example 3.

  The same test was performed on the fuel cell gas seal part of Comparative Example 5 using the hydrogen permeation test described above, but there was no permeation of hydrogen at both room temperature and 700 ° C. After repeating this test 23 times, hydrogen permeation occurred, and no defect occurred in the bonding layer made of the glass-based bonding material.

  In Comparative Example 5, since the thickness of the coating film made of a ferritic stainless steel foil was less than 10 μm, it was considered that the fatigue failure (crack) occurred due to repeated thermal deformation in the coating film made of foil. As described above, when the thickness of the coating film is set to 10 to 30 μm, it is possible to flexibly follow the thermal deformation of the component parts, and it has been proved that a durable gas sealing property can be obtained.

  As described above, the fuel cell gas seal components 1, 21, 31, 41, 51, 61, 71 of each example can be demonstrated to have excellent gas seal properties, and Even when the component S1 and the other component S2 are thermally deformed and a tensile force or a compressive force is applied to the joint portion, excellent gas sealability and bondability are maintained. Was able to prove.

FIG. 4 is a cross-sectional explanatory view (a) in a state where fuel cell gas seal parts according to an embodiment of the present invention are arranged between constituent parts, and a cross-sectional explanatory view (b) in a state of following the deformation of the constituent parts. Example 1 It is a disassembled perspective explanatory drawing which shows the positional relationship of the gas seal component for fuel cells in FIG. 1, and a component. Example 1 FIG. 2 is an explanatory cross-sectional view of a state in which the fuel cell gas seal component in FIG. 1 is set in a hydrogen permeation tester. Example 1 FIG. 6 is a cross-sectional explanatory view showing a state in which gas seal parts for a fuel cell according to another embodiment of the present invention are arranged between constituent parts. (Example 3) FIG. 6 is a cross-sectional explanatory view of a fuel cell gas seal component according to still another embodiment of the present invention. Example 4 FIG. 6 is a cross-sectional explanatory view showing a state in which the fuel cell gas seal component in FIG. 5 is arranged between the components. Example 4 FIG. 6 is an explanatory plan view (a) and a sectional explanatory view (b) of a gas seal part for a fuel cell according to still another embodiment of the present invention. (Example 5) FIG. 8 is an exploded perspective view illustrating a procedure for manufacturing a fuel cell stack structure by disposing a fuel cell gas seal component in FIG. 7 between components. (Example 5) FIG. 6 is an explanatory plan view (a) and a sectional explanatory view (b) of a gas seal part for a fuel cell according to still another embodiment of the present invention. (Example 6) FIG. 10 is an exploded perspective view showing the positional relationship between the fuel cell gas seal part and the component parts in FIG. 9. (Example 6) FIG. 6 is an explanatory plan view (a) and a sectional explanatory view (b) of a gas seal part for a fuel cell according to still another embodiment of the present invention. (Example 7) FIG. 12 is an explanatory cross-sectional view of a state in which the fuel cell gas seal component in FIG. 11 is arranged between the components. (Example 7) FIG. 13 is a perspective explanatory view of a flat plate type fuel electrode supporting cell that is a component shown in FIG. 12. (Example 7) FIG. 6 is a cross sectional explanatory view (a) and a vertical cross sectional explanatory view (b) of a gas seal part for a fuel cell according to still another embodiment of the present invention. (Example 8) FIG. 15 is a cross-sectional explanatory view of a state in which the fuel cell gas seal component in FIG. 14 is arranged between the component components. (Example 8) FIG. 16 is a cross-sectional explanatory view of a cylindrical type fuel electrode supporting cell that is a component shown in FIG. 15. (Example 8) It is manufacturing process explanatory drawing of the gas-seal component for fuel cells of this invention. FIG. 3 is an explanatory diagram of a component joining process using a gas seal part for a fuel cell according to the present invention.

Explanation of symbols

1, 21, 31, 41, 51, 61, 71 Gas seal parts for fuel cells 2 Core body 3 Coating film 4 Bonding layer S1, S2 Component parts

Claims (12)

A gas seal component disposed between components that require gas seal in a fuel cell, and has an elastic core body, a coating film made of a metal foil covering the core body, and formed on the surface of the coating film And a bonding layer made of a glass-based bonding material that is bonded to both the one component and the other component between the components ,
A gas seal component for a fuel cell, wherein a difference in coefficient of thermal expansion between a coating film made of a metal foil and a bonding layer made of a glass-based bonding material is 2 × 10 ⁻⁶ (1 / K) or less . A gas seal component disposed between components that require gas seal in a fuel cell, and has an elastic core body, a coating film made of a metal foil covering the core body, and formed on the surface of the coating film And a bonding layer made of a glass-based bonding material that is bonded to both the one component and the other component between the components ,
A gas seal component for a fuel cell, characterized in that a difference in coefficient of thermal expansion between a bonding layer made of a glass-based bonding material and a component to which the bonding layer is bonded is 2 × 10 ⁻⁶ (1 / K) or less. . The gas seal part for a fuel cell according to claim 1 or 2 , wherein the coating film made of metal foil has a thickness of 10 to 30 µm. The gas seal component for a fuel cell according to any one of claims 1 to 3 , wherein the thickness of the bonding layer made of the glass-based bonding material is 10 to 50 µm. Be placed between components in a state where the gas seal, of claims 1 to 4 to expose the one end face either of the end surfaces located on the end face and the counter gas flow side located on the gas flow side of the core body The gas seal part for fuel cells according to any one of the items. The gas seal component for a fuel cell according to any one of claims 1 to 5 , wherein a portion functioning as a partition wall of the coating film is a thick partition wall portion in a state where the gas seal is disposed between the component parts. . The gas seal part for a fuel cell according to any one of claims 1 to 6 , wherein the core body is made of an inorganic porous material. The gas seal part for a fuel cell according to claim 7 , wherein the core body is made of a ceramic fiber assembly which is an inorganic porous material. The gas seal part for a fuel cell according to any one of claims 1 to 8 , wherein the coating film is made of a stainless steel metal foil. In manufacturing the gas seal part for a fuel cell according to any one of claims 1 to 9 , after covering the elastic core body with a coating film made of a metal foil, a glass-based bonding material is applied to the surface of the coating film. The manufacturing method of the gas-seal component for fuel cells characterized by forming the joining layer which consists of. A fuel cell, wherein the gas seal part for a fuel cell according to any one of claims 1 to 9 is arranged between components requiring a gas seal. The fuel cell gas according to any one of claims 1 to 9 , wherein a fuel cell comprising a cell plate as a component holding a single cell and a separator plate as a component is produced between the cell plate and the separator plate. A method of manufacturing a fuel cell, wherein seal parts are arranged and stacked on each other.

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