JP2004281353A - Separator for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a thin, light weight separator, by laminating two metal sheets. <P>SOLUTION: The separator is for a fuel cell having a fuel gas passage and an oxidant gas passage that are disposed inside for flowing reaction gas. The separator 8 comprises two metal sheets 8a, 8b with the flat surfaces bonded together. The fuel gas passage and the oxidant gas passage are formed on the bonded surfaces. A groove 9a for the fuel gas passage and a groove 10a for the oxidant gas passage are provided in the bonded surface of the both or one of the two metal sheets 8a, 8b for forming a passage for the reaction gas. By bonding the both, the fuel gas passage and the oxidant gas passage are formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell separator having a reaction gas passage therein, and more particularly to a separator formed by joining a plurality of metal plates.
[0002]
[Prior art]
2. Description of the Related Art In recent years, solid oxide fuel cells have attracted attention as third-generation fuel cells for power generation. Three types of solid oxide fuel cells, a cylindrical type, a monolith type, and a flat plate type, have been proposed. In each case, a solid electrolyte composed of an oxide ion conductor is provided with an air electrode (cathode) and a fuel electrode from both sides. It has a laminated structure sandwiched between (anodes). When a desired number of power generation cells composed of the stack are alternately stacked with separators with a fuel electrode current collector and an air electrode current collector interposed therebetween, a fuel cell stack having a predetermined output can be formed.
[0003]
In a solid oxide fuel cell, oxidant gas (oxygen) is supplied to the air electrode side and fuel gas (H ₂ , CO, CH _4, etc.) is supplied to the air electrode side as reaction gases. Both the air electrode and the fuel electrode are porous layers so that the gas can reach the interface with the solid electrolyte.
Oxygen supplied to the air electrode side reaches the vicinity of the interface with the solid electrolyte layer through pores in the air electrode layer, receives electrons from the air electrode at this portion, and is ionized into oxide ions (O ²⁻ ). Is done. The oxide ions diffuse and move in the solid electrolyte layer toward the fuel electrode. The oxide ions that have reached the vicinity of the interface with the fuel electrode react with the fuel gas at this portion to generate a reaction product (H ₂ O, CO _2, etc.), and emit electrons to the fuel electrode. These electrons can be taken out as an electromotive force by an external circuit of another route.
[0004]
Here, generally, the solid electrolyte layer is composed of stabilized zirconia (YSZ) to which yttria is added, and the fuel electrode layer is a metal such as Ni or Co or a cermet such as Ni-YSZ or Co-YSZ. Wherein the air electrode layer is made of LaMnO ₃ , LaCoO ₃ or the like, and the fuel electrode current collector is made of a sponge-like porous sintered metal plate such as a Ni-based alloy, and the air electrode current collector is made of Is made of a sponge-like porous sintered metal plate such as an Ag-based alloy, and the separator is made of ceramics having electronic conductivity such as lanthanum chromite (LaCrO ₃ ), or stainless steel, a nickel-based alloy, or a chromium-based alloy. And the like.
[0005]
Generally, a ceramic separator is used for a high-temperature operation type fuel cell that operates at about 1000 ° C., and a metal separator is used for a low-temperature operation type fuel cell that operates at about 700 ° C. In particular, a metal separator is suitable for a flat plate type fuel cell. This metal separator has a function of electrically connecting the power generation cells and a function of supplying a reaction gas to the power generation cells, and a fuel gas is introduced into the inside of the separator from the outer peripheral surface of the separator to form a fuel electrode layer of the separator. And a oxidizing gas passage for discharging an oxidizing gas from an outer peripheral surface of the separator and discharging the oxidizing gas from a surface of the separator facing the oxidizing electrode layer.
[0006]
The flat-plate stacked solid oxide fuel cell having the above configuration is disclosed in, for example, Patent Document 1.
[0007]
[Patent Document 1]
JP-A-2002-203588
[Problems to be solved by the invention]
By the way, the above-mentioned fuel gas passage and the oxidizing gas passage are generally formed by a straight drilling process performed from the outside of the metal plate. It is a simple structure that only connects the part and the center linearly. Therefore, the length of the gas passage is naturally limited to a short one.
[0009]
Therefore, when it is desired to form a particularly long gas passage in expectation of the preheating of the fuel gas inside the separator and the cooling effect of the fuel cell by the oxidizing gas (air), each gas as disclosed in Patent Document 1 is used. A passage structure is employed in which the passage meanders over a wide range of the metal plate. In this case, the structure is a combination of straight drilling performed from the outside to the inside of the separator and groove processing on the outer side of the separator, and finally the opening of the groove is formed from the side of the separator to a member such as a side plate. , A series of meandering gas passages can be formed.
[0010]
However, the structure of the gas passage formed by such drilling or grooving has the following problems.
In other words, in order to perform the horizontal drilling from the side of the separator, a hole diameter (for example, a gas passage of about 2.5 to 3φ) capable of securing a necessary gas flow rate can be formed, depending on the battery output. It was necessary to use a single metal plate having a thickness of about 5 to 10 mm. However, when such a thick metal single plate is used for the separator material, the weight of the unit cell itself increases, and in a fuel cell stack configured by stacking a large number of the unit cells, the unit cell disposed below has a high pressure in the upper layer. Therefore, there is a problem that the fuel cell stack is easily deformed and damaged. Therefore, a strong support mechanism for supporting the weight of the fuel cell stack is required, so that the structure becomes complicated. Also, the thicker the separator, the larger the fuel cell.
[0011]
Further, the configuration of Patent Document 1 having a meandering gas passage inside the separator requires a plurality of side plates for sealing the opening of the groove, and a brazing plate for joining these side plates to the side portions of the separator. An attaching process and a laser welding process are required, and the assembling work is complicated.
The present invention has been made in view of the above-mentioned conventional problems, and provides a separator for a fuel cell in which a separator is a laminated structure of a plurality of metal plates to facilitate formation of an internal gas passage and to reduce the thickness and weight. It is an object.
[0012]
[Means for Solving the Problems]
That is, the present invention according to claim 1 is a fuel cell separator provided with a fuel gas passage and a oxidizing gas passage that serve as reaction gas passages therein, and the separator has flat surfaces joined to each other. A fuel gas passage and an oxidizing gas passage are formed on a joint surface of the metal plate.
[0013]
According to a second aspect of the present invention, there is provided the fuel cell separator according to the first aspect, wherein the fuel cell separator includes two metal plates, and only one of the two metal plates to be bonded is provided with a metal plate. A fuel gas passage groove and an oxidizing gas passage groove for forming the reaction gas passage are provided.
[0014]
According to a third aspect of the present invention, there is provided the fuel cell separator according to the first aspect, wherein the fuel gas separator includes two metal plates, and the reaction gas is provided on both joining surfaces of the two metal plates to be joined. And a fuel gas passage groove and an oxidizing gas passage groove for forming the passages.
[0015]
According to a fourth aspect of the present invention, there is provided the fuel cell separator according to the first aspect, wherein the fuel gas separator has a structure including two metal plates, and the reaction gas is provided on one joint surface of the two metal plates to be joined. And a oxidizing gas passage groove is provided on the other joint surface.
[0016]
According to a fifth aspect of the present invention, in the fuel cell separator according to the first aspect, the fuel gas passage and the oxidizing gas passage are formed by cutting out a fuel gas passage for forming each gas passage. It is characterized by being formed by joining a plurality of metal plates provided with cutouts for oxidizing gas passages.
[0017]
According to a sixth aspect of the present invention, in the fuel cell separator according to any one of the first to fifth aspects, any one of Ni, Ag, Sn, Zn, and Cr is formed on the surface of the metal plate. Characterized in that at least one or more coating layers consisting of
[0018]
According to a seventh aspect of the present invention, in the fuel cell separator according to any one of the first to sixth aspects, the fuel gas passage and the oxidizing gas passage are each formed in a spiral shape. It is characterized by:
[0019]
Here, according to the configuration of any one of the first to fourth aspects, a groove for a gas passage is formed in advance on a joint surface of two metal plates, and the two are joined together. Since a gas passage can be formed on the joint surface, not only a simple gas passage having only a straight portion but also a complicated gas passage having a curved portion (for example, a spiral gas passage) regardless of its shape. It can be formed relatively easily, and the manufacturing cost can be reduced. In the case of this structure, for example, a relatively thin metal plate of, for example, about 0.5 to 1 mm can be used, and the separator itself can be thinned. Therefore, the fuel cell stack can be made thinner and lighter. I can plan.
In particular, in the structure in which the gas passage groove is formed only in one of the two metal plates as described in claim 2, the thickness of the metal flat plate in which the gas passage is not formed can be reduced by the groove. This is extremely effective in reducing the thickness and weight of the separator.
[0020]
Also, as in the configuration according to claim 5, each gas passage can be formed by laminating and pressing a plurality of metal plates provided with cutouts, and in this method, the gas passage can be formed more easily. become.
[0021]
Further, in the configuration according to the sixth aspect, the heat resistance and corrosion resistance of the separator (a stainless steel, a nickel-based alloy, a chromium-based alloy, or the like is used as a metal material) are improved, and the separator is used in a fuel cell operating environment. Oxidation of the separator surface is prevented, and good electrical continuity with each current collector can be secured for a long period of time. Therefore, internal resistance can be reduced and the performance of the fuel cell can be improved.
[0022]
Further, by forming each gas passage in a spiral shape over the entire area of the separator, the flow path of the fuel gas or the oxidizing gas can be lengthened. Thereby, in the preheating at the start of operation, the entire region of the separator can be uniformly heated by flowing a heating gas from the outside into these gas passages. In the process of flowing the fuel cell, the fuel gas can be efficiently preheated by the heat exchange action with the high-temperature separator, and the fuel cell stack can be efficiently cooled by extending the flow path of the oxidizing gas.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
First, the configuration of a solid oxide fuel cell to which the present invention is applied will be described with reference to FIG. FIG. 4 shows a configuration of a main part of a flat plate type solid oxide fuel cell.
The unit cell includes a power generation cell 5 having a fuel electrode layer and an air electrode layer disposed on both sides of a solid electrolyte layer, a fuel electrode current collector 6 disposed outside the fuel electrode layer, and a power cell 5 disposed outside the air electrode layer. It comprises an air electrode current collector 7 disposed and a separator 8 disposed outside each of the current collectors 6 and 7. The fuel cell stack 1 is formed by stacking a large number of the single cells with an insulating fuel manifold ring 15 and an insulating oxidant manifold ring 16 interposed therebetween.
By stacking, the respective manifold rings 15 and 16 are connected in the stacking direction via the respective gas introduction holes 13 and 14 provided in the separator 8 to form two tubular manifolds 17 and 18 parallel to both sides of the stack. Is done. In addition, a fuel gas and an oxidizing gas (generally, air) supplied from the outside flow through each of the manifolds 17 and 18.
[0024]
Although the same physical properties as those of the related art can be used for each element constituting the single cell, the present invention is different from the conventional type in which the structure of the separator 8 is a thick metal single plate.
[0025]
Hereinafter, the structure of the separator 8 according to the first embodiment of the present invention will be described with reference to FIGS.
[0026]
The separator 8 of this embodiment is formed by joining two thin rectangular stainless steel plates having a thickness of, for example, about 0.5 to 1 mm, each of which is made of stainless steel as a metal base material and whose surface is subjected to Ni plating and Ag plating. It has a two-layer structure composed of an upper plate 8a and a lower plate 8b. A fuel gas introduction hole 13 is formed at the left end of the metal plate, and an oxidizing gas introduction hole 14 is formed at the right end. Each of the gas introduction holes 13 and 14 has an elliptical shape penetrating in the plate thickness direction.
[0027]
By applying Ag plating to a stainless steel plate that is a heat-resistant alloy, the oxidation resistance of stainless steel is further improved, and a separator that has excellent oxidation resistance and heat resistance in a high-temperature oxidation atmosphere during fuel cell operation is configured. it can. In addition, Sn, Zn, Cr, etc. other than Ni and Ag can be used as the plating material, and the plating treatment using these plating materials and the combination of these plating materials also gives the separator 8 the same excellent oxidation resistance. Gives heat resistance.
[0028]
In FIG. 1, the joint surface between the upper plate 8a and the lower plate 8b has a groove 9a for the fuel gas passage which becomes the fuel gas passage 9 and a groove for the oxidant gas passage which becomes the oxidant gas passage 10 shown in FIG. A groove 10a is formed. In the present embodiment, each of the grooves 9a and 10a is formed in a spiral shape that is disposed over substantially the entire surface of the separator 8, and when the upper plate 8a and the lower plate 8b are overlapped, each of the grooves 9a, Each of the gas passages 9 and 10 has a quadrangular cross-section at its joint surface.
[0029]
In the upper plate 8a, one end of the fuel gas passage groove 9a communicates with the fuel gas introduction hole 13, and the other end communicates with the fuel gas discharge hole 9b near the center. One end of the oxidant gas groove 10a communicates with the oxidant gas introduction hole 14, and the other end is closed near the center.
[0030]
On the other hand, in the lower plate 8b, contrary to the upper plate 8a, one end of the oxidant gas groove 10a communicates with the oxidant gas introduction hole 14, and the other end thereof discharges the oxidant gas near the center. It communicates with the hole 10b. Further, one end of the fuel gas groove 9a communicates with the fuel gas introduction hole 13, and the other end has a structure that closes near the center.
[0031]
The fuel gas discharge holes 9b and the oxidant gas discharge holes 10b both penetrate in the plate thickness direction. However, when stacked, the separators 8 located at the uppermost layer and the lowermost layer are fuel Only one of the gas discharge hole 9b and the oxidant gas discharge hole 10b is provided.
[0032]
Next, FIGS. 2A to 2C show a second embodiment of the separator according to the present invention.
The separator 8 according to the second embodiment is the same as the first embodiment shown in FIG. 1 with respect to the base material and the surface plating treatment, but differs in the structure of the gas passages 9 and 10, and has a recess as the upper plate 8a. A flat plate without the grooves 9a, 10a, etc. is used. However, only the fuel gas discharge holes 9b are formed near the center of the upper plate 8a. The lower plate 8b has a structure similar to that of FIG.
[0033]
That is, in the present configuration, by overlapping the upper plate 8a and the lower plate 8b, the openings of the concave grooves 9a, 10a formed in the lower plate 8b are sealed by the upper plate 8a to form the gas passages 9, 10. . In such a structure, the groove processing of the separator is halved as compared with the structure of FIG. 1, so that the manufacture of the separator 8 is facilitated and the thickness of the metal plate having no gas passage can be reduced. -It has the advantage of being extremely effective in reducing weight.
[0034]
Further, FIGS. 3A to 3C show a third embodiment of the separator according to the present invention, in which a fuel gas passage groove 9a is formed in an upper plate 8a of two metal plates 8a and 8b. Thus, the oxidizing gas passage groove 10a is formed in the lower plate 8b.
One end of the fuel gas passage groove 9a provided in the upper plate 8a communicates with the fuel gas introduction hole 13, and the other end communicates with the fuel gas discharge hole 9b near the center. One end of the oxidant gas groove 10a provided in the lower plate 8b communicates with the oxidant gas introduction hole 14, and the other end communicates with the oxidant gas discharge hole 10b near the center.
[0035]
In this configuration, when the upper plate 8a and the lower plate 8b are overlapped, the opening of the groove 10a of the lower plate 8b is sealed by the flat portion of the upper plate 8a, and the opening of the groove 9a of the upper plate 8a. The portion is sealed by the flat portion of the lower plate 8b to form each gas passage 9, 10.
Such a structure has an advantage that the groove processing of the separator can be simplified and the strength of the separator itself can be improved by reducing the groove processing of each metal plate.
[0036]
Next, the flow of the reaction gas in the fuel cell stack 1 having the above configuration will be described with reference to FIG. 1. The fuel gas and the oxidizing gas supplied from the outside are supplied by a fuel gas supply pipe (not shown) and an oxidizing gas supply. The gas is introduced into the fuel gas manifold 17 and the oxidizing gas manifold 18 via pipes. In the process of flowing the reaction gas upward through the manifolds 17 and 18 from below, each gas flows through the gas passages 9 and 10 of each separator 8 while being distributed from the gas introduction holes 13 and 14 of each layer (single cell). It is supplied to the electrode layer of the power generation cell 5.
[0037]
That is, the fuel gas in the fuel gas manifold is introduced into the fuel gas passage 9 from the fuel gas introduction hole 13 of each separator 8, and from the fuel gas discharge port 11 at the end of the passage via the fuel gas discharge hole 9 b near the center. The gas is discharged upward, supplied to the facing anode current collector 6, and diffused through the porous sintered metal plate to form a gas flow path reaching the anode layer of the power generation cell 5.
On the other hand, the oxidizing gas in the oxidizing gas manifold is introduced into the oxidizing gas passage 10 from the oxidizing gas introduction hole 14 of each separator 8 and oxidized at the end of the passage through the oxidizing gas discharge hole 10b near the center. A gas flow path that is discharged from the agent gas discharge port 12 and supplied to the facing air electrode current collector 7 and diffuses through the porous sintered metal plate to reach the air electrode layer of the power generation cell 5; Become.
[0038]
Hereinafter, the electrochemical reaction in each electrode is as described in the section of the prior art, and the high-temperature exhaust gas generated by this electrochemical reaction is discharged from each unit cell 5 out of the stack through a predetermined exhaust route. You.
[0039]
As described above, any structure may be used in which the separator 8 has a two-layer structure formed by laminating two metal plates, a groove for a gas passage is formed on a joint surface thereof, and the two are joined to form a gas passage. For example, it is possible to easily form not only a straight gas passage as in the past, but also a complicated gas passage in which a long flow path can be obtained with a small area such as a spiral shape. Thin and lightweight.
[0040]
Particularly, as described above, when each gas passage is formed in a spiral shape to secure a long gas passage, in preheating at the start of operation (at the time of start-up), heated gas introduced from outside is supplied to these fuel gas passages. 9 and the oxidizing gas passage 10, the inside of the separator 8 is uniformly heated over the entire area in the plane direction by the heat exchange action at that time, and the temperature of the power generation cell is efficiently raised with a uniform temperature distribution. can do. As a result, the thermal stress in the cell caused by the non-uniform temperature distribution can be reduced, and the power generation cell can be prevented from being damaged.
Also, during operation (at the time of power generation), in the process of flowing through the long gas passage, the fuel gas comes into contact with the high-temperature separator, and the fuel gas can be efficiently preheated by the heat exchange action. The fuel cell stack can be heated with a small amount of cooling air by increasing the temperature of the fuel gas and supplying the fuel gas to the fuel electrode current collector 6. 1 can be efficiently cooled.
[0041]
In order to ensure the above-mentioned effects, the surface area of each gas passage 9, 10 should be at least 4% or more of the contact area with the power generation cell.
[0042]
Here, the concave grooves 9a and 10a are formed by a mechanical etching method using an abrasive, a chemical etching method using a chemical (wet etching, dry etching), or an electrolytic method performed by energizing in a liquid phase. Various known etching processing techniques such as an etching method can be used. In the present embodiment, a chemical etching method suitable for fine and high-precision processing is used.
[0043]
Further, the upper plate 8a and the lower plate 8b were joined by a known thermocompression bonding method in which heat and load were simultaneously applied to obtain a laminated and integrated separator 8. In this thermocompression bonding method, the adhesiveness of the bonding surface is good, and excellent airtightness is obtained. Therefore, the separator 8 having a two-layer structure has a high gas sealing property at the bonding surface. .
In addition, it is extremely preferable to perform a polishing process (mirror polishing) on the joint surface between the metal plates, in addition to the above-described Ni plating, Zn plating, Sn plating, Ag plating, and the like, from the viewpoint of airtightness.
[0044]
5 and 6 show a fourth embodiment of the separator according to the present invention.
The separator 8 of the present embodiment is different from the first to third embodiments described above, and is formed in a spiral shape formed by stacking a plurality of metal plates provided with cutouts for gas passages penetrating in the thickness direction. The fuel gas passage 30 and the oxidizing gas passage 31 are provided.
[0045]
As shown in FIG. 5, the separator 8 is formed of a metal disk having a predetermined thickness, and has a spiral fuel gas passage 30 through which the fuel gas flows, and a oxidant gas flowing therein. And a spiral oxidizing gas passage 31 which is formed in a nested state. One end of the fuel gas passage 30 opens to the side of the separator 8, and the other end communicates with a fuel gas discharge hole 32 that opens to the upper surface near the center, and one end of the oxidizing gas passage 31 connects to the side of the separator 8. And the other end thereof communicates with an oxidizing gas discharge hole 33 which is opened at the lower surface near the center.
[0046]
As shown in FIG. 6, the separator 8 includes a metal thin plate (upper plate 34) having a fuel gas discharge hole 32 formed near the center, a spiral cutout 30a for a fuel gas passage, and an oxidizing gas. A metal thin plate (middle plate 35) in which spiral cutouts 31a for passages are provided in a nested state and a metal thin plate (lower plate 36) having an oxidizing gas discharge hole 33 formed near the center are sequentially overlapped and joined. It has a multilayered structure. The joining can be performed by a thermocompression bonding method as in the above embodiment.
By overlapping the upper plate 34, the middle plate 35, and the lower plate 36, the cutouts 30a, 31a of the plurality of middle plates 35 are aligned with each other, and spiral gas passages 30, 31 having a rectangular cross section are formed inside the separator. Can be formed. In the present embodiment, two middle plates 35 are stacked to form a four-layer structure. However, the number of the middle plates 35 is appropriately stacked according to a required gas flow rate. Further, the surface area of each of the gas passages 30 and 31 is preferably set to 4% or more of the contact area with the power generation cell.
[0047]
The configuration of the gas passage according to the present embodiment has an advantage that it can be easily manufactured by pressing (punching) a thin metal plate without using the etching processing technology described in the above embodiment, and further reduces the weight and thickness. Can be achieved.
[0048]
As described above, in the present embodiment, the separator of the solid oxide fuel cell (SOFC) using a solid oxide such as zirconia as an electrolyte has been described. However, the present invention is not limited to this. Of course, the present invention can be applied to separators used in PAFC), a molten carbonate fuel cell (MCFC) using a molten carbonate as an electrolyte, or a polymer electrolyte fuel cell (PEFC) using an ion exchange membrane as an electrolyte. is there.
[0049]
【The invention's effect】
As described above, according to the present invention as set forth in claims 1 to 4, the separator has a structure in which two metal plates are bonded to each other, and a groove for a gas passage is formed in a joint surface thereof, and both are formed. Since the gas passage is formed by joining, a complicated gas passage that can obtain a long flow path with a small area, such as a meandering shape or a spiral shape, can be easily formed, and the manufacturing cost can be reduced. In addition, the thickness and weight of the separator can be reduced.
[0050]
According to the fifth aspect of the present invention, since each gas passage is formed by laminating and pressing a plurality of metal plates provided with cutouts, the gas passage is more easily formed by pressing a thin metal plate. It is possible to further reduce the thickness and weight of the separator.
[0051]
According to the present invention, since at least one coating layer made of any of Ni, Ag, Sn, Zn, and Cr is formed on the surface of the metal plate, the heat resistance of the separator is improved.・ Increasing corrosion resistance, preventing oxidation of the separator surface under the operating environment of the fuel cell, and ensuring good electrical conduction with each current collector for a long period of time. Performance can be improved. Also, excellent gas tightness can be obtained at the joint surface of the separator, so that high gas sealing properties can be ensured.
[0052]
Further, according to the present invention, since each gas passage is formed in a spiral shape over the entire area of the separator, the flow path of the fuel gas and the oxidizing gas can be lengthened. During preheating, the entire area of the separator can be uniformly heated by flowing a heating gas from the outside into these gas passages.Furthermore, during power generation, fuel gas flows through the long gas passages. Can be efficiently preheated, and the fuel cell stack can be efficiently cooled by extending the flow path of the oxidizing gas.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a structure of a separator according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing the structure of a separator according to a second embodiment.
FIG. 3 is a perspective view showing the structure of a separator according to a third embodiment.
FIG. 4 is a cross-sectional view showing a configuration of a main part of a flat-plate stacked solid oxide fuel cell to which the present invention is applied.
5A and 5B show a separator according to a fourth embodiment of the present invention, wherein FIG. 5A is a plan view and FIG. 5B is a side view.
FIG. 6 is an exploded perspective view showing the configuration of the separator of FIG.
[Explanation of symbols]
8 Separator 8a, 34 Metal plate (upper plate)
35 metal plate (medium plate)
8b, 36 metal plate (lower plate)
9, 30 fuel gas passage 9a groove for fuel gas passage (concave groove for fuel gas passage)
10, 31 Oxidizing gas passage 10a Oxidizing gas passage groove (oxidizing gas passage groove)
30a Cutout for fuel gas passage 31a Cutout for oxidant gas passage

Claims (7)

A fuel cell separator having a fuel gas passage and an oxidizing gas passage that serve as a passage for a reaction gas therein,
A fuel cell separator comprising a plurality of metal plates whose planes are joined to each other, wherein a fuel gas passage and an oxidizing gas passage are formed on the joint surface. A fuel gas passage groove and an oxidizing gas passage groove for forming the reaction gas passage are formed only on one joint surface of the two metal plates to be joined. The fuel cell separator according to claim 1, wherein the separator is provided. A structure in which two metal plates are provided, and a fuel gas passage groove and an oxidizing gas passage groove for forming the reaction gas passage are provided on both joint surfaces of the two metal plates to be joined. The fuel cell separator according to claim 1, wherein: A fuel gas passage groove for forming the reaction gas passage is formed on one joint surface of the two metal plates to be joined, and an oxidant gas passage is formed on the other joint surface of the two metal plates. The fuel cell separator according to claim 1, wherein the separator is provided with a groove. The fuel gas passage and the oxidizing gas passage are formed by joining a plurality of metal plates provided with fuel gas passage cutouts and oxidizing gas passage cutouts for forming respective gas passages. The fuel cell separator according to claim 1, wherein The fuel according to any one of claims 1 to 5, wherein at least one or more coating layers made of any of Ni, Ag, Sn, Zn, and Cr are formed on the surface of the metal plate. Battery separator. 7. The fuel cell separator according to claim 1, wherein the fuel gas passage and the oxidizing gas passage are each formed in a spiral shape.

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