JP2009181712A - Laminated fuel cell, separator/gasket aggregate for fuel cell, and fuel cell separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated fuel cell capable of shortening the size of the laminated cell in a lamination direction through alleviation of stress of a sealing part, with high output density achieved through reduction of a volume of the battery, and excellent in power generation characteristics, long-term stability, and safety. <P>SOLUTION: The laminated fuel cell includes: a unit cell structured of electrolyte, electrodes arranged at either face of the electrolyte, and a separator with a pair of gaskets in contact with an outer surface of each electrode; a cooling separator cooling the unit cell; clamping plates clamping a plurality of laminated pieces of the unit cells and the cooling separators; and a high-resistance layer adhered to the separator with the gaskets and at least to the outer surface of the cooling separator. Further, the separator/gasket aggregate and the separator are also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stacked fuel cell, a fuel cell separator / gasket assembly, and a fuel cell separator, and more particularly to a stacked fuel cell in which a plurality of polymer electrolyte fuel cells are stacked.

  In recent years, global warming and environmental pollution problems due to mass consumption of fossil fuels have become serious problems. As a means of coping with this problem, instead of internal combustion engines that burn fossil fuels, solid polymer fuel cells and other fuel cells that use hydrogen, methanol, etc. as fuels, and oxygen, air containing them, etc., attract attention. Collecting.

  The fuel cell is attracting attention as a clean power generation system because it has less burden on the environment of the waste generated by power generation. In particular, due to the recent increase in interest in environmental protection, the development of applications for fuel cell distributed power sources and electric vehicle power sources is expected.

  In addition, as a high energy density power source, the possibility of using a fuel cell as a power source for a mobile device is being studied.

  Examples of the fuel cell include a solid polymer type, a phosphoric acid type, a molten carbonate type, and a solid oxide type. Among them, the polymer electrolyte fuel cell can generate power at a relatively low temperature from room temperature to about 100 ° C., and has a high output density. Therefore, the polymer electrolyte fuel cell is most suitable for the above-mentioned applications. .

  A polymer electrolyte fuel cell generally has a structure in which a supported carbon layer (hereinafter simply referred to as an electrode catalyst layer) supporting a catalyst metal serving as an anode and a cathode is disposed on both sides of a solid polymer electrolyte membrane. It is configured. Here, a diffusion layer is disposed on the surface opposite to the solid polymer electrolyte membranes of the anode and cathode in order to smoothly diffuse hydrogen, methanol, air, and oxygen as fuel.

  In the polymer electrolyte fuel cell, for example, when hydrogen is used as the fuel, water is generated from the hydrogen in the fuel and the oxygen in the air by the reaction represented by the following reaction formula during power generation.

Anode side H ₂ → 2H ⁺ + 2e ⁻
Cathode ^{_{1 / 2O 2 + 2H + +}} 2e - → H 2 O
Total reaction H ₂ + 1 / 2O ₂ → H ₂ O
In the above reaction, a maximum voltage of about 1 V is generated during power generation of the polymer electrolyte fuel cell. In the polymer electrolyte fuel cell, a single cell outputs only a voltage of about 1 V at the maximum as described above. For this reason, a stacked fuel cell in which a plurality of single cells are stacked in accordance with the output scale and electrically connected in series is used in an actual system. Fuel cells for fuel cell vehicles are required to have an output of 50 to 70 kW, and 200 to 500 single cells need to be stacked. When the number of stacks increases, the output voltage of the stacked fuel cell increases, and the output voltage when stacking 200 to 500 cells is 200 to 500V. Such an increase in the output voltage of the stacked battery facilitates the occurrence of a short circuit between the stacked cells, causing a decrease in power generation characteristics, long-term stability, and safety.

  In addition, as separators for fuel cells for mobile vehicles such as fuel cell vehicles that require high power density, development of metal material separators that are easier to mold than carbon-based materials and that can reduce the separator thickness is underway. . When the separator thickness is reduced, the volume of the stacked battery can be reduced and the output density can be improved. In addition, since the separator is thin, a seal structure is required to cope with the deformation of the separator. At the same time, when the cells are short-circuited, the short-circuit path is shortened, so that the short-circuit current is increased and the influence on power generation characteristics, long-term stability, safety, and the like is increased.

  Against this background, a stacked fuel cell structure has been proposed in which a short circuit is prevented by covering the outer surface of the stacked battery or the manifold surface with a sealing material for preventing leakage of fuel, oxidant and refrigerant to the outside. ing. (For example, see Patent Documents 1, 2, and 3).

JP 2002-305006 A JP 2004-047495 A Japanese Patent Laid-Open No. 2002-207074

  Since the thickness of the separator has been reduced due to the development of the metal material separator, the degree of influence of the thickness of the sealing material to prevent the leakage of fuel, oxidant, and refrigerant to the outside has a relatively large effect on the volume of the stacked battery. It has become.

  In the prior art, the outer periphery of the separator that serves as the outer surface of the stacked fuel cell with a sealing material for preventing leakage of fuel, oxidant, and refrigerant to the outside as a structure that prevents short-circuiting between cells while accommodating deformation of the separator In addition, a stacked fuel cell structure that prevents a short circuit by covering a manifold opening on the surface of the manifold has been proposed. If the separator opening and the manifold opening on the surface of the manifold are covered with the sealing material in this way, the shape of the sealing material becomes complicated, so it is difficult to mold the separator outer periphery and the manifold opening with high dimensional accuracy. Yes, the seal material becomes relatively thick. In addition, since the stress in the stacking direction is applied to the seal portion, the strength of the metal material separator becomes a problem.

  An object of the present invention is to provide a stacked fuel cell that can shorten the dimension of the stacked battery in the stacking direction, has a high output density by reducing the volume of the stacked battery, and has excellent power generation characteristics, long-term stability, and safety. Is to provide.

  According to the present invention, an electrolyte, electrodes disposed on both surfaces of the electrolyte, a unit cell constituted by a pair of gasketed separators in contact with each outer surface of the electrode, and a cooling separator for cooling the unit cell A plurality of the unit cells and a plurality of the cooling separators and a clamping plate for fastening both ends, and having a high resistance layer in close contact with at least the outer peripheral surface of the separator with the gasket and the cooling separator, A stacked fuel cell is provided. Here, the outer peripheral surface of the separator does not necessarily include its end face, but means that it includes at least the surface laminated with the gasket. Of course, a high resistance layer may also be formed on the end face. The high resistance layer may be insulative in a normal sense.

  The present invention also provides a separator having a desired flow path for separating fuel and oxidant gas or cooling water, a manifold for supplying fuel or oxidant gas or cooling water to the flow path, or discharging the flow path from the flow path, A separator / gasket assembly for a fuel cell having a pair of gaskets in contact with both surfaces of the separator and having a high resistance layer in the vicinity of the manifold of the separator.

  Furthermore, the present invention provides a fuel cell separator having a fluid flow path formed by molding a metal body, a manifold, and a high resistance layer in close contact with the outer peripheral surface and the vicinity of the manifold.

  According to the present invention, it is possible to shorten the dimension of the stacked battery in the stacking direction, reduce the volume of the stacked battery, increase the output density, and have excellent power generation characteristics, long-term stability, and safety. Can be provided.

  Preferred embodiments of the present invention are exemplified below. It is desirable to form the high resistance layer on the manifold with the gasketed separator and the cooling separator and in the vicinity thereof.

  In addition, at least one of the gasketed separator and the cooling water separator is at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium, and alloys of the metals. Preferably it consists of. When these metals are used, it is easy to form a high resistance layer in the outer periphery of the separator as the outer surface of the stacked fuel cell and the manifold opening as the manifold surface. This ensures insulation between cells with a thin seal member configuration, relieves stress at the seal part, shortens the dimension of the stacked battery in the stacking direction, reduces the volume of the stacked battery, and increases the output density. In addition, it is possible to provide a stacked fuel cell that is excellent in power generation characteristics, long-term stability, and safety.

  Moreover, it is preferable that at least one of the said separator with a gasket and the said cooling water separator consists of a several metal clad material. The intermediate layer of the clad material is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and alloys of the metal, and the metal The outermost surface of the layer is preferably composed of a metal selected from titanium, zirconium, tantalum, niobium, tungsten, chromium, aluminum, gold, platinum, ruthenium, palladium and alloys thereof.

  What has the intermetallic compound layer comprised by the metal adjacent to the boundary surface of each layer of the said cladding material can be used.

  The high resistance layer is preferably formed by oxidation treatment, thermal spraying or anodizing treatment that forms an insulating film that adheres to the surface of the separator and does not easily peel off or fall off.

  A cooling separator that uses an electrolyte and electrodes disposed on both sides of the electrolyte and a pair of gasketed separators covering each outer surface of the electrode as a unit cell and cools the unit cell or a plurality of the unit cells using a refrigerant. In a stacked fuel cell in which a plurality of unit cells and cooling separators are stacked and both ends are tightened with a clamping plate, the separator and the cooling separator are in close contact with the outer peripheral portion of the stacked fuel cell The thin high resistance layer is formed.

  The stacked fuel cell is characterized in that a high resistance layer is formed in a manifold opening that forms a manifold surface of a pair of separators and cooling separators that cover the outer surfaces of the electrodes. The thickness of the high resistance layer is preferably 0.5 to 300 μm, particularly 1 to 100 μm. The resistance of the high resistance layer is preferably 1 kΩ or more.

  It is preferable that the gasketed separator and the cooling water separator are made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and alloys of the metals. Of these, Ti and Al are particularly preferred, because they form a dense oxide layer on the surface. This oxide has a high resistance value and excellent corrosion resistance. Further, these metals have a small specific gravity and light weight, which is an important advantage as a fuel cell.

  Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a separator 1 showing the first embodiment. However, the separator 1 is brought into contact with the gaskets 5 facing the front and back surfaces to form a separator / gasket assembly. The separator 1 is made of metal, has a flat periphery, and is formed by extruding and pressing the center portion to form a flow path. The flat portion 2 is a portion necessary for making the surface contact with the gasket 5, and the flow passage portion 3 is an uneven groove for allowing reaction gas (general name of fuel gas and oxidant gas) and cooling water to flow through the front and back of the separator. It is. Further, a manifold 4 serving as an inlet / outlet for the reaction gas and the cooling water is formed. Two gaskets 5 are in close contact with each other on the flat portion 2 on the front and back surfaces of the separator 1 to constitute a separator 101 with a gasket.

  When the separator 1 according to the present embodiment is used in an actual battery, the unit cell is combined with a gas diffusion layer 6, MEA (Membrane Electrode Assembly) 7 and the like. As shown in FIG. 1, a high resistance layer 30 is formed in the outer periphery of the separator 1 and in the vicinity of the manifold. Thereby, the insulation between cells is ensured with a thin seal | sticker part structure, the stress of a seal | sticker part can be relieve | moderated, and the dimension of a lamination direction can be made small. Moreover, if a thin high-resistance layer is formed on the surface of the separator by oxidation treatment, thermal spraying, or the like, a fuel cell excellent in power generation characteristics, long-term stability and safety of the fuel cell can be provided.

  FIG. 2 shows an example of a battery configuration using the separator according to this embodiment. The separator 101 to which the gasket 5 is bonded is composed of two types. The separator 101 with the gasket for allowing the reaction gas to flow on both sides is represented by the reference numeral 101A. In addition, a separator for the reaction gas on one side and a separator for the cooling water on the other side is represented by a symbol 101B. Therefore, for convenience, 101A is referred to as a separator with a gasket, and 101B is referred to as a cooling separator.

  Gas diffusion layer 6 / MEA 7 / gas diffusion layer 6 are sandwiched between the gas flow surfaces of separator 101A or 101B with gasket, thereby forming one single cell. In addition, a stacked fuel cell is formed using the current collector plate 8, the insulating plate 9 and the end plate 10.

  The separator 1 shown in FIG. 1 is in contact with the gas diffusion layer 6 which is an adjacent member at the apex of the convex surface of the separator 1. Therefore, the convex vertex of the separator 1 needs to have conductivity. The other surfaces are irrelevant to electrical conduction, and therefore do not require conductivity, and may be an insulating layer or may be conductive.

  FIG. 5 is a partial cross-sectional view of FIG. 2, in which a separator / gasket assembly 23 (a separator for fuel and oxidant gas used only for the power generation unit 20), MEA 7 and separator / gasket assembly 24 ( A separator for fuel or oxidant gas and cooling water, one side is used for power generation and the other is used for the cooling water part 21 or only for the cooling part 21).

  FIG. 3 is a view schematically showing a cross section taken along the line AA of the separator 1 shown in FIG. The high resistance layer 12 is formed on the separator material on the outer periphery of the separator 1 that becomes the outer surface of the stacked fuel cell.

  FIG. 4 is a diagram schematically showing a cross section taken along the line BB ′. The high resistance layer 12 is formed on the separator material at the outer periphery of the separator 1 that is the outer surface of the stacked fuel cell and the manifold opening that is the surface of the manifold 4.

  With this configuration, the outer surface of the stacked fuel cell and the manifold 4 are covered with the high resistance layer 12, so that a short circuit is formed on the outer surface of the stacked fuel cell due to contact of conductors or accumulation of dust or the like. Even if formed, the resistance of the short circuit becomes high, and the short circuit current can be reduced to a current value that has little influence on the power generation characteristics. This ensures insulation between the cells of the stacked fuel cell with a simple configuration and improves power generation characteristics, long-term stability, and safety.

  Another embodiment of the present invention will be described. Depending on the type of the outermost layer metal, the separator 1 may not have sufficient long-term stability in the first embodiment. If the outer layer of the separator 1 does not have sufficient corrosion resistance, such as nickel, significant corrosion occurs and causes deterioration of the battery. Therefore, it is preferable that the metal selected as the outer layer has a certain degree of corrosion resistance. Of these, titanium, zirconium, tantalum, niobium, and tungsten are highly corrosion-resistant metals, and at the same time, release of corrosion products is extremely small compared to other metals. This is because the corrosion product has a property of staying on the surface as an oxide film. Therefore, the adverse effect on the electrode and the electrolyte membrane is small, and is a preferable metal in the fuel cell.

  Aluminum has poor corrosion resistance compared to the above metals, but even if it corrodes, a film having the same quality as alumite is produced, so the amount of corrosion products released is relatively small. Chromium forms a stable passive region over a wide potential range and is corrosion resistant. Gold, platinum, ruthenium, palladium and the like are classified as noble metals and have very high corrosion resistance.

  By selecting such a metal as the outermost layer of the separator 1, elution of metal ions is reduced, and a long-life separator that can minimize deterioration of the electrodes and electrolyte membrane of the MEA 7 can be expected.

  Another embodiment of the present invention will be described. When the outermost layer metal of the separator 1 is iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium, or an alloy of these metals, oxides of these metals exhibit high resistance. Therefore, the high resistance layer 12 is formed by heat treatment or acid treatment so that oxides are not formed on the outer peripheral portion of the separator 1 that is the outer surface of the stacked fuel cell and on the manifold surface other than the manifold opening. To do. At this time, the high resistance layer 12 having an arbitrary thickness can be formed by controlling and selecting the heat treatment temperature, time, acid treatment temperature, time, and type of acid. This ensures insulation between the cells of the stacked fuel cell with a simple configuration and improves power generation characteristics, long-term stability, and safety. It is preferable that the high resistance layer is in close contact with the separator, is not peeled off or dropped off, is thin, and is as smooth as possible. Thereby, the unit cells can be easily adhered and stacked without impairing a large number of handling properties.

  Another embodiment of the present invention will be described. When tantalum, tungsten, gold, platinum, ruthenium, palladium, or an alloy of the metal is used as the outermost layer metal of the separator 1, these metals hardly generate oxides. Therefore, masking is applied to portions other than the outer peripheral portion of the separator 1 that is the outer surface of the stacked fuel cell and the manifold opening that is the manifold surface, and the high resistance layer 12 is formed by thermal spraying. As the material to be sprayed, an oxide ceramic material can easily form the high resistance layer 12, and aluminum oxide, zirconium oxide, titanium oxide, and the like are preferable. This ensures insulation between the cells of the stacked fuel cell with a simple configuration and improves power generation characteristics, long-term stability, and safety.

  Another embodiment of the present invention will be described. When aluminum, titanium, or an alloy of the metal is used as the outermost layer metal of the separator 1, the high resistance layer 12 can be easily formed by anodizing these metals. Therefore, masking is applied to the outer peripheral portion of the separator 1 which is the outer surface of the stacked fuel cell and the manifold opening which is the manifold surface, and the high resistance layer 12 is formed by anodizing. This ensures insulation between the cells of the stacked fuel cell with a simple configuration and improves power generation characteristics, long-term stability, and safety.

  When the resistance of the high resistance layer 12 is 10 kΩ, assuming that the output voltage of the stacked fuel cell is 500 V, the short-circuit current is 0.05 A at maximum if a short-circuit is formed. This is a sufficiently small value compared to the current taken out from the stacked fuel cell. Therefore, if the resistance of the high resistance layer 12 is 10 kΩ or more, the power generation characteristics, long-term stability, and safety are sufficiently maintained. .

Example 1
Specific examples of the present invention will be described. An example in which stainless steel (SUS304) and copper (C1100) are used for the intermediate layer and titanium (TP270) and nickel (Nickel200) are used for the outer layer of the multilayer metal plate used for the separator 1 is shown. A coiled separator substrate can be formed by clad a thin layer of titanium or nickel on both sides of stainless steel or copper of a coiled thin plate by cold rolling.

  The finished thickness of the separator substrate used here was 0.2 mm. Since the separator substrate after being clad is work-hardened, it is annealed at a temperature of 400 to 800 ° C. to obtain a plate material having properties suitable for subsequent press working. In order to form the flow channel groove, it is processed into a separator having an uneven shape on both sides of the flat portion and the central portion with an extrusion press. At the same time, punching is performed to form the manifold 4. Thereby, the thing of the shape equivalent to the separator 1 shown in FIG. 1 can be manufactured. However, the finishing accuracy after press molding differs depending on the material of the intermediate layer. The multilayer metal plate (outer layer was titanium) with copper as the intermediate layer had a small warp and a flatness of about 1/100.

  In the case where stainless steel was selected as the intermediate layer, the warp was about 3/100, which was larger than that of copper. Finishing accuracy depends greatly on the intermediate layer, and finishing accuracy is higher for metals with lower elastic modulus and metals with higher elongation. Accordingly, metals such as copper and aluminum are suitable when accuracy needs to be increased. However, as described below, when the anticorrosion performance of the coating layer is small, corrosion may occur at a portion where the intermediate layer is exposed in the manifold 4, and the corrosion resistance of the intermediate layer and the anticorrosion property of the coating layer are taken into consideration. It is necessary to select materials.

Next, a method for forming an oxide high resistance layer on the processed separator will be described. Prior to forming the oxide high resistance layer, blasting for removing the oxide film, polishing, or pickling is performed according to the surface state of the separator after processing. Next, degreasing treatment with an alkali or an organic solvent is performed. Thereafter, the outer periphery of the separator forming the oxide high resistance layer and the manifold opening are covered with a cooling jacket, and a high-frequency heater is disposed on the outer periphery and the manifold opening, and rapidly increases to 400 to 800 ° C. in the air. The separator was oxidized by overheating. Thereby, the separator 1 is completed.
The gasket 5 is manufactured by punching a flat or sheet-like elastic body. As the material, silicon rubber, EPDM and the like excellent in heat resistance, water resistance and creep resistance are suitable. The gasket 5 may be made of a hard material such as PPS without being an elastic body. However, since the sealing effect is small, a liquid gasket or the like needs to be adhered between the separator 1 and the gasket 5. The separator 101 with a gasket is obtained by the above.

  The material used above is an example for explaining the present embodiment, and the present invention is not limited to this. Further, the separator manifold, the flow path structure, the gasket structure, and the battery configuration are merely examples, and the present invention is not limited thereto. There are also various processes for producing a multilayer metal plate, and appropriate means can be selected as necessary.

(Example 2)
Specific examples of the present invention will be described. An example in which stainless steel (SUS304) and copper (C1100) are used for the intermediate layer and titanium (TP270) and nickel (Nickel200) are used for the outer layer of the multilayer metal plate used for the separator 1 is shown. A coiled separator substrate can be formed by clad a thin layer of titanium or nickel on both sides of stainless steel or copper of a coiled thin plate by cold rolling.

  The finished thickness of the separator substrate used here was 0.2 mm. Since the separator substrate after being clad is work-hardened, it is annealed at a temperature of 400 to 800 ° C. to obtain a plate material having properties suitable for subsequent press working. In order to form the flow channel groove, it is processed into a separator having an uneven shape on both sides of the flat portion and the central portion with an extrusion press. At the same time, punching is performed to form the manifold 4. Thereby, the thing of the shape equivalent to the separator 1 shown in FIG. 1 can be manufactured.

  Next, the processed separator was masked except for the outer peripheral portion of the separator and the manifold opening, and the metal surface of the sprayed portion was roughened by blasting so that the sprayed coating was in close contact. Thereafter, an alumina film was formed by thermal spraying. Depending on the surface state of the separator after thermal spraying, blasting for removing the oxide film, polishing, or pickling is performed. Next, degreasing treatment with an alkali or an organic solvent is performed. Thereby, the separator 1 is completed.

  The gasket 5 is manufactured by punching a flat or sheet-like elastic body. As the material, silicone rubber, EPDM and the like excellent in heat resistance, water resistance and creep resistance are suitable. The gasket 5 may be made of a hard material such as PPS without being an elastic body. However, since the sealing effect is small, a liquid gasket or the like needs to be adhered between the separator 1 and the gasket 5. The separator 101 with a gasket is obtained by the above.

  The material used above is an example for explaining the present embodiment, and the present invention is not limited to this. Further, the separator manifold, the flow path structure, the gasket structure, and the battery configuration are merely examples, and the present invention is not limited thereto. There are also various processes for producing a multilayer metal plate, and appropriate means can be selected as necessary.

(Example 3)
Still another specific embodiment of the present invention will be described. An example in which aluminum (A5052) is used for the intermediate layer and titanium (TP270) is used for the outer layer in the multilayer metal plate used for the separator 1 is shown. A thin layer of titanium can be clad by cold rolling on both sides of the coiled aluminum sheet to produce a coiled separator substrate. The finished thickness of the separator substrate used here was 0.2 mm. Since the separator substrate after being clad is work-hardened, it is annealed at a temperature of 400 to 800 ° C. to obtain a plate material having properties suitable for subsequent press working.

  In order to form the flow channel groove, it is processed into a separator having an uneven shape on both sides of the flat portion and the central portion with an extrusion press. At the same time, punching is performed to form the manifold 4. Thereby, the thing of the shape equivalent to the separator 1 shown in FIG. 1 can be manufactured.

  Next, a method for forming an oxide high resistance layer on the processed separator will be described. Prior to forming the high resistance layer by anodizing, blasting for removing the oxide film, polishing, or pickling is performed according to the surface state of the separator after processing. Next, degreasing treatment with an alkali or an organic solvent is performed. Thereafter, the portions other than the outer periphery of the separator and the manifold opening were formed to form the oxide high resistance layer.

  In the anodizing treatment, 3 to 10% oxalic acid was used in the electrolytic bath, the voltage was 30 to 100 V, the temperature was 10 ° C. or less, the treatment time was 20 to 120 minutes, and the film thickness was 20 to 50 μm. Then, the sealing process was performed in boiling water. Thereby, the separator 1 is completed.

  The gasket 5 is manufactured by punching a flat or sheet-like elastic body. The material is preferably silicon rubber, EPDM or the like which is excellent in heat resistance, water resistance and creep resistance. The gasket 5 may be made of a hard material such as PPS without being an elastic body. However, since the sealing effect is small, a liquid gasket or the like needs to be adhered between the separator 1 and the gasket 5. The separator 101 with a gasket is obtained by the above.

  The material used above is an example for explaining the present embodiment, and the present invention is not limited to this. Further, the separator manifold, the flow path structure, the gasket structure, and the battery configuration are merely examples, and the present invention is not limited thereto. There are also various processes for producing a multilayer metal plate, and appropriate means can be selected as necessary.

The expansion | deployment perspective view which shows the structure of the separator gasket integrated body by the Example of this invention. 1 is an exploded perspective view showing a configuration of a fuel cell to which the present invention is applied. 1 is a partial cross-sectional view of the separator along the line A-A 'in FIG. FIG. 4 is a partial cross-sectional view of the separator along B-B ′ in FIG. 1, which is another embodiment. Sectional drawing of the upper end part of the fuel cell shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Separator, 2 ... Flat part, 3 ... Flow part, 4 ... Manifold, 5 ... Gasket, 6 ... Gas diffusion layer, 7 ... MEA, 8 ... Current collecting plate, 9 ... Insulating plate, 10 ... End plate, 12 ... High resistance layer, 20 ... power generation unit, 21 ... cooling unit, 23 ... power generation unit separator, 24 ... cooling unit separator, 30 ... high resistance layer, 101A ... separator with gasket, 101B ... cooling separator.

Claims (18)

  An electrolyte, electrodes disposed on both surfaces of the electrolyte, a unit cell composed of a pair of gasketed separators in contact with the outer surfaces of the electrode, a cooling separator for cooling the unit cell, and the unit cell A laminated fuel cell comprising a plurality of the cooling separators and a clamping plate for fastening both ends, and having a high resistance layer in close contact with at least the outer peripheral surface of the separator with gasket and the cooling separator.   2. The stacked fuel cell according to claim 1, wherein the high resistance layer is formed on an outer periphery, a manifold and the vicinity thereof of the gasketed separator and the cooling separator.   At least one of the separator with gasket and the cooling separator is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and alloys thereof. The stacked fuel cell according to claim 1 or 2, characterized in that:   The stacked fuel cell according to any one of claims 1 to 3, wherein at least one of the gasketed separator and the cooling separator is made of a plurality of metal clad materials.   The intermediate layer of the clad material is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and an alloy of the metal, 5. The laminated fuel according to claim 4, wherein the outermost surface is made of a metal selected from titanium, zirconium, tantalum, niobium, tungsten, chromium, aluminum, gold, platinum, ruthenium, palladium, and alloys thereof. battery.   6. The stacked fuel cell according to claim 5, wherein an intermetallic compound layer composed of adjacent metals is formed on a boundary surface of each layer of the clad material.   The stacked fuel cell according to claim 1, wherein the high resistance layer is formed by oxidation treatment, thermal spraying, or anodization treatment.   The stacked fuel cell according to claim 1, wherein a resistance value of the high resistance layer is 10 kΩ or more.   A desired flow path for separating fuel and oxidant gas or cooling water, a separator having a manifold for supplying or discharging fuel, oxidant gas or cooling water to the flow path, and contacting both surfaces of the separator A separator / gasket assembly for a fuel cell, which has a pair of gaskets and has a high resistance layer on the outer peripheral surface of the separator, a manifold, and the vicinity thereof.   10. The fuel according to claim 9, wherein the separator is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium, and alloys thereof. Battery separator / gasket assembly.   The fuel cell separator / gasket assembly according to claim 9 or 10, wherein the separator is made of a plurality of metal clad materials.   The intermediate layer of the clad material is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and alloys of the metal, and the clad material 12. The fuel cell according to claim 11, wherein the outermost surface is made of a metal selected from titanium, zirconium, tantalum, niobium, tungsten, chromium, aluminum, gold, platinum, ruthenium, palladium, and alloys thereof. Separator / gasket assembly.   13. The fuel cell separator / gasket assembly according to claim 12, wherein an intermetallic compound layer composed of adjacent metals is formed on a boundary surface of each layer of the clad material.   The fuel cell separator / gasket assembly according to any one of claims 9 to 12, wherein the high resistance layer is formed by oxidation treatment, pardon or folding oxidation.   A fuel cell separator having a fluid passage formed by molding a metal body, a manifold, and a high resistance layer in close contact with the outer peripheral surface and the vicinity of the manifold.   16. The separator according to claim 15, wherein the separator is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium, and an alloy of the metal. Fuel cell separator.   The fuel cell separator according to claim 15 or 16, wherein the separator is made of a plurality of metal clad materials.   The intermediate layer of the clad material is made of at least one metal selected from iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chromium and an alloy of the metal, 18. The fuel cell according to claim 17, wherein the outermost surface is made of a metal selected from titanium, zirconium, tantalum, niobium, tungsten, chromium, aluminum, gold, platinum, ruthenium, palladium, and alloys thereof. Separator.

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