JP2015002022A - Fuel cell stack and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell stack in which the weight of a rust-proof plate for suppressing corrosion of a separator can be reduced, while reducing the manufacturing cost.SOLUTION: In a fuel cell stack 1 where terminal plates 11 are arranged at both ends of a cell laminate 3 laminating a plurality of fuel cells 2 including a separator 31, a rust-proof plate 60 is provided between the separator 31 and the terminal plate 11. The layer of the rust-proof plate 60 including a surface facing the separator 31 is constituted of a corrosion resistant metal plate 62, and the layer of the rust-proof plate 60 including a surface facing the terminal plate 11 is constituted of a casting part 71 having a specific gravity smaller than that of the corrosion resistant metal plate 62.

Description

  The present invention relates to a fuel cell stack and a manufacturing method thereof.

  The fuel cell has an MEA (Membrane-Electrode-Assembly: electrolyte membrane-electrode assembly), and exposes both main surfaces of the MEA to a fuel gas containing hydrogen and an oxidizing gas containing oxygen such as air. Thus, the fuel gas and the oxidizing gas are electrochemically reacted to generate electric power and heat.

  In general, a fuel cell is formed by stacking fuel cells to form a cell stack, and terminals and end plates are arranged at both ends of the cell stack in the cell stacking direction, and the end plates at both ends are fastened by fastening members such as bolts. The fastened fuel cell stack is the main body. The fuel battery cell is configured by sandwiching the MEA between a pair of flat separators. The separator has a fuel gas channel for supplying fuel gas to the anode, an oxidizing gas channel for supplying oxidizing gas to the cathode, and a refrigerant channel for flowing refrigerant in the power generation region. The separator has a fuel gas manifold, an oxidizing gas manifold, and a refrigerant manifold in the non-power generation region. The separator is made of a conductive material such as resin or metal containing conductive carbon.

  In general, water is used as a cooling medium flowing through the cooling medium manifold and the cooling medium flow path. When water is used as a cooling medium, even if a low conductivity material such as ion exchange water is used, it has conductivity, so the fuel is supplied via the cooling water filled in the cooling medium manifold. A short circuit occurs between the positive and negative members in the battery stack, specifically, between the conductive separators. As a result, a short-circuit current flows through the separator, leading to corrosion of the wall surface forming the cooling medium manifold hole provided in the positive separator.

  A fuel cell stack in which a sacrificial member is provided between a positive electrode terminal and a separator on the positive electrode terminal side is known in order to solve the problem of such corrosion of the separator (see, for example, Patent Document 1). ).

JP 2007-087766 A

  However, in the fuel cell stack described in Patent Document 1, carbon is used as the sacrificial member, and therefore, depending on the fastening load when fastening the end plates at both ends, the stress concentration due to set screws, and the impact force at the time of vehicle collision There is a risk of cracking. For this reason, it is desired to employ a metal as a member that does not easily crack due to stress concentration or impact force. However, if it is formed with a thickness that satisfies the required rigidity, there arises a problem that the weight of the fuel cell stack increases. Moreover, in order to ensure the sealing performance between the sacrificial member and the cell stack, it is necessary to cut the surface of the sacrificial member. There was also the problem of spending time. This cutting time problem becomes a significant problem when Ti (titanium) is used as the metal, because Ti is a difficult-to-cut material, and in addition, the cutting tool wears sharply and the tool cost increases. There was also a problem that it would end up.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fuel cell stack including a metal plate that can suppress corrosion of the separator and can reduce the weight and the cost. It is to provide.

  In order to solve the above-described problems, a fuel cell stack according to the present invention has terminal plates arranged at both ends of a cell stack in which a plurality of fuel cells each including a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are stacked. A rust preventive plate is provided between the separator and the terminal plate, and the rust preventive plate has a layer including a surface facing the separator of the rust preventive plate having corrosion resistance and conductivity. The layer including the surface facing the terminal plate of the rust prevention plate is composed of a second metal having a specific gravity smaller than that of the first metal.

  Thus, since the layer including the surface that opposes the separator in the rust prevention plate is composed of the first metal having corrosion resistance and conductivity, the stress concentration due to the fastening load and the set screw is suppressed while suppressing the corrosion of the separator. Further, it is possible to prevent the rust preventive plate from being cracked due to an impact at the time of a vehicle collision. Moreover, since the layer including the surface which opposes the terminal plate in the rust prevention plate is composed of the second metal having a specific gravity smaller than that of the first metal, the weight of the rust prevention plate can be reduced. As a result, when the fuel cell is mounted on the vehicle, the inertial impact force at the time of the vehicle collision is reduced by the weight reduction, so that the impact resistance performance can be improved.

  In the fuel cell stack according to the present invention, the first metal is formed with a recess formed by pressing, and the recess is in contact with a gasket bonded to the separator. The first metal sealed between the separator has a recess formed by pressing, and the recess is in contact with a gasket formed on the separator. It is also preferable that the gap is sealed.

  In this preferable aspect, since the concave portion is formed by pressing the first metal instead of cutting, the man-hour and cutting cost by cutting can be suppressed. Further, since the recess is in contact with the gasket, the gap between the rust prevention plate and the separator can be sealed, so that leakage of hydrogen gas, oxidizing gas, and the like can be suppressed.

  In the fuel cell stack according to the present invention, the first metal is formed of a material having high strength, and the second metal is formed thicker than the plate thickness of the first metal. Is also preferable.

  In this preferred embodiment, since the first metal is formed of a material having high strength, the rust preventive plate is caused by a fastening load in the stacking direction by the end plate, stress concentration by a set screw, an impact at the time of a vehicle collision, or the like. Cracking can be suppressed. Moreover, since the 2nd metal with smaller specific gravity is formed thicker than the ratio of the 1st metal, weight reduction can be achieved as the whole rust prevention plate.

  A method for manufacturing a fuel cell stack according to the present invention is a fuel comprising a terminal plate disposed at both ends of a cell stack in which a plurality of fuel cells each including a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are stacked. A method for manufacturing a battery stack, the step of forming irregularities on a first metal having corrosion resistance and conductivity by pressing, and a second metal having a specific gravity smaller than that of the first metal, The step of integrating with a metal, and the separator, the first metal, the second metal, and the terminal plate are laminated in this order.

  By constructing in this way, an unevenness is formed in the first metal not by cutting but by pressing, and a second metal having a small specific gravity is integrated with the first metal to produce a rust prevention plate. Therefore, it is possible to reduce the number of man-hours and cutting tool costs by cutting.

  In addition, the fuel cell stack manufacturing method according to the present invention includes terminal plates disposed at both ends of a cell stack in which a plurality of fuel cell cells each including a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are stacked. A method of manufacturing a fuel cell stack, comprising a step of forming a flat first metal having corrosion resistance and conductivity by pressing, and a flat second metal having a specific gravity smaller than that of the first metal by pressing. Forming a concavo-convex structure on the surface of the first metal by laminating the first metal and the second metal, the separator, the first metal, and the second metal The metal and the terminal plate are laminated in this order.

  Thus, since the metal plate which does not have the uneven | corrugated shape shape | molded by press work is laminated | stacked and the antirust plate is manufactured, a process difficulty can be made low. As a result, processing time can be shortened and mass productivity can be improved.

  In the method of manufacturing a fuel cell stack according to the present invention, it is also preferable that a portion of the first metal that does not come into contact with hydrogen gas or cooling water forms a metal having a specific gravity smaller than that of the first metal.

  In this preferable aspect, since the ratio of the metal with a small specific gravity in a rust prevention plate can be enlarged, the further weight reduction of a rust prevention plate can be achieved, suppressing the corrosion of a separator.

  In the method for manufacturing a fuel cell stack according to the present invention, it is also preferable that the first metal is formed of a different type of metal plate depending on the fluid in contact therewith.

  In this preferred embodiment, the rust prevention plate is formed using a different type of metal plate depending on the fluid to be contacted, so that the cost can be further reduced.

  According to the present invention, it is possible to reduce the weight of the rust prevention plate for suppressing the corrosion of the separator. For this reason, when the fuel cell stack provided with the rust prevention plate according to the present invention is mounted on the vehicle, the inertial impact force at the time of the vehicle collision is reduced, and the impact resistance performance can be improved. In addition, when manufacturing a corrosion-resistant metal plate that constitutes a rust-proof plate, a fuel cell stack is provided that can cut costs and reduce costs by adopting a manufacturing method that includes pressing. be able to.

1 is a side view showing a schematic configuration of a fuel cell stack according to an embodiment of the present invention. It is a fragmentary sectional view of the fuel cell stack concerning the embodiment of the present invention. It is a perspective view which shows the rust prevention plate with which the fuel cell stack which concerns on 1st Embodiment of this invention is provided. It is a perspective view which shows the rust prevention plate with which the fuel cell stack concerning 2nd Embodiment of this invention is provided. It is sectional drawing which shows the state compared about the manufacturing method of the antirust plate in 2nd Embodiment of this invention, and the manufacturing method of the antirust plate in 1st Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view showing a schematic configuration of a fuel cell stack 1 according to an embodiment of the present invention.

  The fuel cell stack 1 includes a cell stack 3 in which a plurality of fuel cells 2 that generate power by an electrochemical reaction between a fuel gas and an oxidizing gas are stacked, and both ends in the cell stacking direction, in order from the cell stack 3 side, Rust prevention plate 60, terminal plate 11, and end plate 12 are provided. The end plate 12 clamps and holds the plurality of fuel cells 2 in the stacking direction via tie rods (not shown). A pair of end plates 12 are provided at both ends in the stacking direction, and used as, for example, an in-vehicle fuel cell stack 1.

  Next, the fuel cell 2 constituting the fuel cell stack 1 will be further described with reference to FIG. FIG. 2 is a partial cross-sectional view of the fuel cell stack 1.

  The fuel cell 2 includes a membrane electrode assembly (MEA) 21, a pair of separators 31 (an anode side separator 31a and a cathode side separator 31b) that sandwich the MEA 21, a seal member 22, a gasket 23, and the like. The seal member 22 is formed between the anode side separator 31a and the cathode side separator 31b. The gasket 23 is bonded to the separator 31 and is formed between the fuel cells 2.

  The MEA 21 is composed of a polymer electrolyte membrane made of an ion exchange membrane of a polymer material (hereinafter also simply referred to as an electrolyte membrane) and a pair of electrodes (an anode side diffusion electrode and a cathode side diffusion electrode) that sandwich the electrolyte membrane from both sides. Has been. The electrolyte membrane is formed larger than each electrode. Each electrode is joined to the electrolyte membrane by, for example, a hot press method. Each electrode constituting the MEA is made of, for example, a porous carbon material (diffusion layer) carrying a catalyst such as platinum attached to the surface thereof. One electrode (anode) is supplied with hydrogen gas as a fuel gas (reactive gas), and the other electrode (cathode) is supplied with an oxidizing gas (reactive gas) such as air or an oxidant. An electrochemical reaction occurs in the MEA, and an electromotive force of the fuel cell 2 is obtained.

  The anode side separator 31a and the cathode side separator 31b are made of a gas impermeable conductive material. Examples of the conductive material include carbon and a hard resin having conductivity, and metals such as stainless steel (Fe, Cr, Ni, etc.).

  A fuel gas flow path for supplying fuel gas to the anode is formed in the anode separator 31a in the power generation region. In addition, a refrigerant flow path for flowing the refrigerant is also formed. The cathode-side separator 31b has a MEA 21-side surface formed by a substantially flat flat plate without a groove, but an oxidizing gas passage for supplying an oxidizing gas to the cathode may be formed.

  At one end in the longitudinal direction of the anode side separator 31a and the cathode side separator 31b and in the non-power generation region, an inlet side manifold 41 of fuel gas, oxidizing gas or cooling water is formed. In addition, fuel gas, oxidizing gas, or cooling water outlet side manifolds 42 and 43 are formed at the other end in the longitudinal direction of the anode side separator 31a and the cathode side separator 31b. The inlet side manifold 41 and the outlet side manifolds 42 and 43 are formed by substantially rectangular or trapezoidal holes. The fuel gas, the oxidizing gas, or the refrigerant is sealed with an adhesive or a sealing material such as a gasket 23 adhered to the peripheral edge of the separator 31 so that leakage is suppressed.

  Next, the rust prevention plate 60 will be further described with reference to FIG. FIG. 3A is a perspective view of the rust prevention plate 60. FIG. 3B is a cross-sectional view taken along line AA shown in FIG.

  The rust prevention plate 60 is disposed between the cell laminate 3 and the terminal plate 11. In other words, the rust prevention plate 60 is disposed between the separator 31 and the terminal plate 11. The rust preventive plate 60 has a plate shape having no through hole. The rust prevention plate 60 may be adhered to the terminal plate 11 with a conductive adhesive, or may be sandwiched between the terminal plate 11 and the separator 31 without using an adhesive.

  As shown in FIG. 3, the rust prevention plate 60 includes a corrosion-resistant metal plate 62 and a cast part 71. The layer including the surface facing the cell stack 3 in the rust prevention plate 60, that is, the layer including the surface facing the separator 31 of the fuel cell 2 is configured by the corrosion-resistant metal plate 62.

  The corrosion-resistant metal plate 62 is formed of a metal plate material having corrosion resistance and conductivity. For example, a material such as Ti is used. Here, as the degree of corrosion resistance, the corrosion current after about 100 hours passed under the use environment of sulfuric acid pH 3, 80 ° C. and about 0.9 V was measured, and the current value was extrapolated to about 12000 hours, 7.0 × 10 ^ (-4) It is desirable that there is no plate thickness reduction of about μm / hr, and in addition, it is desirable that the hydrogen content is about 100 ppm or less in a hydrogen exposure environment of about 0.3 MPa, 200 ° C., and about 100 hr. Further, the degree of conductivity is preferably about 50 mΩ · cm 2 or less of the contact resistance. Furthermore, it is desirable that the corrosion-resistant metal plate 62 is formed of a material having high strength. The material having high strength is a material that does not crack due to a fastening load in the stacking direction by the end plate 12, a stress concentration by a set screw, an impact at the time of a vehicle collision, and the like, and is preferably a metal material. A recess 62a is formed on the surface of the corrosion-resistant metal plate 62 by pressing. By forming the recess 62a, the surface of the corrosion-resistant metal plate 62 has an uneven shape. The recess 62a can accommodate a sealing material such as the gasket 23 formed on the separator 31 when the rust preventive plate 60 is laminated on the cell laminate 3. When the recess 62a is in contact with the gasket 23, the space between the rust prevention plate 60 and the separator 31 is sealed, and leakage of gas or the like is suppressed.

  Next, the casting part 71 will be described. The casting part 71 is configured by a layer including a surface of the rust prevention plate 60 that faces the terminal plate 11. The surface in contact with the terminal plate 11 in the casting part 71 is a flat surface to ensure conductivity. Further, the surface of the cast portion 71 that contacts the corrosion-resistant metal plate 62 is configured to follow the uneven shape of the corrosion-resistant metal plate 62. Thus, the casting part 71 is comprised so that the volume other than the part in which the corrosion-resistant metal plate 62 in the rust prevention plate 60 was formed may be supplemented. The casting part 71 is manufactured by a method in which, for example, aluminum or an alloy mainly composed of aluminum is melted and press-fitted into a mold by aluminum die casting. The casting part 71 is formed of a lightweight metal (for example, aluminum) having a specific gravity smaller than that of the metal of the corrosion-resistant metal plate 62. The casting part 71 is formed to be thicker than the thickness of the corrosion-resistant metal plate 62, and is designed to be lighter than when the entire rust prevention plate 60 is made of a metal such as Ti. About the corrosion-resistant metal plate 62 and the casting part 71, the ratio or the thickness of each of them is appropriately selected according to the amount of hydrogen gas, the amount of oxidizing gas, and the like.

  Then, the manufacturing method of the antirust plate 60 shown in FIG. 3 is demonstrated. First, the recess 62 a is formed by pressing the corrosion-resistant metal plate 62, and the unevenness is formed on the surface of the corrosion-resistant metal plate 62. Next, the cast part 71 is formed on one surface of the corrosion-resistant metal plate 62 by casting, and the corrosion-resistant metal plate 62 and the cast part 71 are integrated. And what was manufactured with the corrosion-resistant metal plate 62 and the casting part 71 is plated with a material with good conductivity (for example, gold). Thereby, the rust prevention plate 60 is manufactured.

  The fuel cell stack 1 including the manufactured antirust plate 60 is configured as follows. That is, in the fuel cell stack 1, the rust preventive plate 60 is disposed with the surface on the separator 31 side of the rust preventive plate 60 as the corrosion resistant metal plate 62 and the surface of the rust preventive plate 60 on the terminal plate 11 side as the casting portion 71. Has been. In other words, the fuel cell stack 1 has a configuration in which the separator 31 (or the cell stack 3 including the separator 31), the corrosion-resistant metal plate 62, the casting portion 71, and the terminal plate 11 are stacked in this order. Yes.

  Thus, in this embodiment, since one surface of the rust preventive plate 60 is formed of the corrosion resistant metal plate 62, it is cracked into the rust preventive plate 60 due to a stress concentration due to a fastening load, a set screw, or an impact force. Can be prevented. Further, since the portion other than the portion where the corrosion-resistant metal plate 62 is formed in the rust prevention plate 60 is constituted by a cast part 71 such as a lightweight aluminum material, the entire rust prevention plate 60 is made of a metal plate material such as Ti. Compared with the case where it forms, the volume replaced by the casting part 71 and weight reduction can be achieved. As a result, when the fuel cell is mounted on the vehicle, the inertial impact force at the time of the vehicle collision is reduced by the weight reduction, so that the impact resistance performance can be improved.

  Moreover, as a manufacturing method of the rust preventive plate 60, it is not a method of forming irregularities on the surface by cutting the Ti plate material completely, but by forming a recess 62a that accommodates a sealing material such as a gasket by pressing. The surface of the plate material is processed into an uneven shape. Since Ti is a difficult-to-cut material, when a Ti plate material is processed by cutting as in the past, it takes a long time for the cutting process, and tool costs such as cutting tools for cutting increase. I'm sorry. For this reason, as in this embodiment, the processing time of the Ti plate material can be shortened more than before by processing the surface of the Ti plate material into a concavo-convex shape by pressing rather than cutting, and tools such as cutting tools An increase in costs can also be suppressed.

  Next, the rust prevention plate 60 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4A is a perspective view of the rust prevention plate 60. FIG. 4B is a cross-sectional view taken along line AA of the rust prevention plate 60 shown in FIG. The same reference numerals are used for the same parts as the rust prevention plate 60 shown in FIG.

  As shown in FIG. 4, the rust prevention plate 60 includes a first corrosion-resistant metal plate 63 a, a second corrosion-resistant metal plate 63 b, and a thin metal plate 81. A first corrosion-resistant metal plate 63a and a second corrosion-resistant metal plate 63b are formed on the cell laminate 3 side of the rust prevention plate 60, that is, the surface on the separator 31 side. A thin metal plate 81 is formed on the surface of the rust prevention plate 60 on the terminal plate 11 side.

  The first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b have a flat plate shape, and are combined to form a metal plate having an uneven shape on the surface on the cell laminate 3 side. Composed. Specifically, the first corrosion-resistant metal plate 63a is formed of a flat metal plate material over the entire width of the long side and the short side of the rust-preventing plate 60, and the first corrosion-resistant metal plate 63a A plurality of second corrosion-resistant metal plates 63b are arranged on the upper surface. The second corrosion-resistant metal plate 63b has a flat plate shape that is smaller than the width of the long side and the short side of the first corrosion-resistant metal plate 63a, and both longitudinal ends of the first corrosion-resistant metal plate 63a. , Arranged at both ends in the short direction and at the center. As described above, by combining the first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b formed of a flat metal plate material, irregularities are formed on the surface thereof. The material of the first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b may be any material having characteristics such as corrosion resistance, conductivity, and high strength. For example, Ti is used. Can do.

  The thin metal plate 81 is a surface on the terminal plate 11 side of the rust prevention plate 60 and is disposed adjacent to the first corrosion-resistant metal plate 63a. The thin metal plate 81 has the same length as the long side and the short side of the first corrosion-resistant metal plate 63a and is formed of a plurality of flat metal plate materials. The number of the thin metal plates 81 can be set as appropriate, and is determined to an appropriate plate thickness according to the specifications. The thin metal plate 81 is made of a metal having a specific gravity smaller than that of the first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b. For example, aluminum can be used.

  Then, the manufacturing method of the rust prevention plate 60 in 2nd Embodiment shown in FIG. 4 is demonstrated. FIG. 5A shows a state where the metal plate material constituting the rust prevention plate 60 shown in FIG. 4 is disassembled.

  As shown in FIG. 5A, the rust prevention plate 60 of the second embodiment is manufactured by laminating and integrating metal plate materials that have been pressed into a flat shape. Specifically, first, the first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b are formed by press working to have an appropriately set plate thickness. Next, the thin metal plate 81 is formed by press working to have an appropriately set plate thickness. The first corrosion-resistant metal plate 63a and the second corrosion-resistant metal plate 63b and the thin metal plate 81 are integrated by caulking, bolt fastening, welding or the like, and the first corrosion-resistant metal plate 63a and Unevenness is formed on the surface of the second corrosion-resistant metal plate 63b. Apply gold plating if necessary. Thereby, the rust prevention plate 60 is manufactured. Then, the manufactured rust preventive plate 60 is disposed between the cell laminate 3 and the terminal plate 11. That is, as in the first embodiment, the fuel cell stack 1 includes the separator 31 (or the cell stack 3 including the separator 31), the corrosion-resistant metal plate 62, the casting portion 71, and the terminal plate 11 stacked in this order. It has the structure.

  Thus, in 2nd Embodiment, the antirust plate 60 is manufactured by combining the flat metal plate shape | molded by press work. In the second embodiment, since a material having a small specific gravity is used for the rust prevention plate 60, the weight of the rust prevention plate 60 can be reduced. As a result, when the fuel cell is mounted on the vehicle, the inertial impact force at the time of the vehicle collision is reduced by the weight reduction, so that the impact resistance performance can be improved. In addition, since cutting with respect to the corrosion-resistant metal plate, which is a difficult-to-cut material, has been abolished, the processing time can be shortened, the mass productivity can be improved, and the cost of the cutting tool can be reduced.

  Furthermore, the second embodiment has the following excellent effects as compared with the first embodiment. FIG. 5B is a cross-sectional view illustrating a state in which the metal plate material constituting the rust prevention plate 60 in the first embodiment is disassembled. As shown in FIG. 5B, in the first embodiment, it is necessary to form irregularities on the corrosion-resistant metal plate 62 by pressing, whereas in the second embodiment, the corrosion-resistant metal is pressed by pressing. It is not necessary to form irregularities on the metal plate material including the plate 62. For this reason, it becomes a shape with a low processing difficulty, can further aim at shortening of processing time, and can improve mass productivity.

  In the present embodiment, the portion of the rust prevention plate 60 that does not come into contact with the fluid that causes corrosion of the separator 31 such as hydrogen gas or cooling water is the first corrosion resistant metal plate 63a and the second corrosion resistance. The metal plate 63b may be formed of a metal having a specific gravity smaller than that of the conductive metal plate 63b, for example, a light metal such as an aluminum plate. By comprising in this way, the fuel cell stack which can achieve further weight reduction of the rust prevention plate 60 can be provided.

  Moreover, you may comprise the rust prevention plate 60 using a metal plate of a different kind corresponding to the part which fluids, such as hydrogen and cooling water, contact with the rust prevention plate 60. FIG. In other words, an area where each fluid such as hydrogen and cooling water contacts or does not contact is derived in advance, and an optimum metal plate corresponding to each previously derived area (a metal plate having a small specific gravity, corrosion resistance and conductivity). The rust preventive plate 60 may be configured using a metal plate having a high impact resistance or a metal plate having a high impact property. By comprising in this way, the fuel cell stack which can aim at the further cost reduction can be provided.

  As mentioned above, although the Example of this invention was described, this is an illustration for description of this invention, Comprising: It is not the meaning which limits the scope of the present invention only to this Example. The present invention can be implemented in various other embodiments.

1: Fuel cell stack 2: Fuel cell 3: Cell stack 11: Terminal plate 12: End plate 22: Seal member 23: Gasket 31: Separator 31a: Anode-side separator 31b: Cathode-side separators 41, 42, 43: Manifold 60: Rust prevention plates 62, 63a, 63b: Corrosion-resistant metal plate 71: Casting part 81: Thin metal plate

Claims (7)

A fuel cell stack in which terminal plates are arranged at both ends of a cell laminate in which a plurality of fuel cell cells each including a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are laminated,
A rust prevention plate is provided between the separator and the terminal plate,
The rust preventive plate includes a layer including a surface of the rust preventive plate facing the separator, and a layer including the surface of the rust preventive plate facing the terminal plate. Is a fuel cell stack composed of a second metal having a specific gravity smaller than that of the first metal. The first metal has a recess formed by pressing,
2. The fuel cell stack according to claim 1, wherein a gap between the antirust plate and the separator is sealed by contacting the recess with a gasket bonded to the separator. The first metal is formed of a material having high strength,
3. The fuel cell stack according to claim 1, wherein the second metal is formed thicker than a plate thickness of the first metal. A method for producing a fuel cell stack comprising a terminal plate disposed at both ends of a cell laminate in which a plurality of fuel cell cells each comprising a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are laminated,
Forming irregularities on the first metal having corrosion resistance and conductivity by pressing; and
Integrating a second metal having a specific gravity smaller than that of the first metal with the first metal;
A fuel cell stack manufacturing method in which the separator, the first metal, the second metal, and the terminal plate are stacked in this order. A method for producing a fuel cell stack comprising a terminal plate disposed at both ends of a cell laminate in which a plurality of fuel cell cells each comprising a membrane electrode assembly and a separator sandwiching the membrane electrode assembly are laminated,
Forming a flat first metal having corrosion resistance and conductivity by pressing; and
Forming a flat second metal having a specific gravity smaller than that of the first metal by pressing;
Laminating the first metal and the second metal to form irregularities on the surface of the first metal;
A fuel cell stack manufacturing method in which the separator, the first metal, the second metal, and the terminal plate are stacked in this order.   5. The method of manufacturing a fuel cell stack according to claim 4, wherein a portion of the first metal that does not come into contact with hydrogen gas or cooling water forms a metal having a specific gravity smaller than that of the first metal.   7. The method of manufacturing a fuel cell stack according to claim 5, wherein the first metal is formed of a different type of metal plate depending on a fluid in contact therewith.

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