JP2005123003A - Fuel cell separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell separator that can be correctly assembled when assembling a fuel cell.
SOLUTION: A fuel gas channel groove 9 and an oxidizing gas channel groove 9a are formed in a central portion of a single rectangular plate in plan view, and a fuel gas inlet side into which fuel gas flows is formed around the groove 9a. Manifold hole 7a, fuel gas outlet side manifold hole 7b through which fuel gas is discharged, oxidizing gas inlet side manifold hole 8a through which oxidizing gas flows, and oxidizing gas outlet side manifold through which oxidizing gas is discharged Hole 8b is provided. This separator 7 is formed with a notch 10 as a discriminating part between a surface located on the anode side and a surface located on the cathode side by cutting off a part of the corner at the same site as viewed from the anode or the cathode.
[Selection] Figure 2

Description

  The present invention relates to a separator for a fuel cell that is disposed between an anode and a cathode and forms a flow path for a reaction gas in each space between the anode and the cathode. In particular, the fuel cell separator can be assembled correctly. The present invention relates to a fuel cell separator.

  2. Description of the Related Art Conventionally, a fuel cell that converts a chemical energy of a fuel gas into electrical energy by electrochemically reacting a fuel gas such as hydrogen and an oxidizing gas such as air is known (for example, patents). Reference 1).

  FIG. 6 shows a fuel cell described in Patent Document 1. The fuel cell 20 is assembled by stacking a plurality of power generation modules called fuel cells 21 and press-contacting them. The electricity generated by the fuel cell 21 is taken out from the positive electrode 26 and the negative electrode 27 to the outside.

  FIG. 7 is an exploded perspective view of the fuel battery cell 21. The fuel cell 21 includes a solid polymer electrolyte membrane 22, an anode 23 disposed on one side of the solid polymer electrolyte membrane 22, and a cathode 24 disposed on the other side of the solid polymer electrolyte membrane 22. And a separator 25 having a fuel gas flow path 25a for supplying a fuel gas on the surface in contact with the anode 23 and an oxidizing gas flow path 25b for supplying an oxidizing gas on the surface in contact with the cathode 24.

  The fuel cell 20 is assembled by stacking a plurality of fuel cells 21 as shown in FIG. At this time, one separator is interposed between the adjacent fuel cells 21.

  FIG. 8 shows an enlarged partial cross section of the separator 25 of the conventional fuel cell 21. The separator 25 is formed of a material having excellent corrosion resistance, and a fuel gas passage 25a is formed on one surface thereof and an oxidizing gas passage 25b is formed on the other surface thereof by pressing.

  The operation of this conventional fuel cell 20 will be described. In the fuel cell 20, hydrogen gas at about 80 ° C. is introduced into the fuel gas passage 25 a on the anode 23 side, and discharged from a fuel gas outlet (not shown) through the fuel gas passage 25 a. On the other hand, on the cathode 24 side, an oxidizing gas composed of a mixed gas of the atmosphere of about 80 ° C. and water vapor, which is a reaction product of the fuel cell, is introduced from the oxidizing gas inlet and passes through the oxidizing gas flow path 25b and is not shown. Exhaust from oxidizing gas outlet. At the anode 23, the hydrogen gas is decomposed into hydrogen ions and electrons, and the hydrogen ions move toward the cathode 24 through the solid polymer electrolyte membrane 22, and the electrons are transferred to the cathode 24 side via a load by a lead (not shown). Moving. On the other hand, at the cathode 24, oxygen in the mixed gas reacts with electrons that have moved through the load and hydrogen ions that have moved from the anode 23 side to generate water. Thus, electricity can be taken out by creating a flow of electrons through the electrode reaction.

As described above, the surface of the separator 25 that is in contact with the cathode 24 is exposed to an oxidizing gas composed of a mixed gas of water vapor and air at about 80 ° C. to form an oxide film. The function of will be reduced. In order to prevent such deterioration of the function, the separator 25 is formed of a material having excellent corrosion resistance.
JP 2003-197214 A (paragraph 0002)

  However, according to the separator used in the conventional fuel cell, the shape of the fuel gas channel formed on the anode side or the oxidizing gas channel formed on the cathode side is such that the reaction efficiency of hydrogen gas at the anode and the oxidation at the cathode Although it is different from the difference in reaction efficiency of sex gases, it is difficult to distinguish them visually. Therefore, the separator may be attached to the fuel cell by mistake between the surface in contact with the anode and the surface in contact with the cathode. Therefore, if it is installed incorrectly, it cannot be configured to correspond to the difference in reaction efficiency between the fuel gas and the oxidizing gas, and if a non-oxide film is formed on the oxidizing gas flow path side, it will not be used. As a result, the performance of the fuel cell deteriorates, and as a result, the performance of the fuel cell may not be sufficiently brought out.

  Accordingly, an object of the present invention is to provide a fuel cell separator that can be correctly assembled when the fuel cell is assembled.

  In order to achieve the above object, the present invention provides a fuel cell separator disposed between an anode and a cathode, wherein a first reaction gas flow path is formed between the anode and the anode. A first surface, a second surface that is located on the cathode side and forms a flow path of a second reaction gas between the cathode, the first surface, and the second surface. Provided is a fuel cell separator characterized by comprising an identification unit for identification.

  Moreover, it is preferable that the said identification part is what identifies a shape visually.

  Further, it is preferable that the first surface and the second surface have a geometrically asymmetric shape.

  According to the fuel cell separator of the present invention, since the identification portion is formed, it is possible to prevent a mistake that the front and back surfaces of the separator are mistakenly attached when assembling the fuel cell, and the productivity of the fuel cell is improved. In addition, by properly attaching the separator, a configuration corresponding to the difference in reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be sufficiently extracted. In addition, if a non-oxidized film is formed on the oxidizing gas flow path side, it will be used, so that the conductivity decreases due to the formation of an oxide film on the surface in contact with the cathode and the performance of the fuel cell. It is possible to prevent the deterioration and to fully draw out the performance of the fuel cell.

  According to the fuel cell separator of the present invention, since the identification unit can visually identify the shape, the surface of the separator that contacts the anode and the surface that contacts the cathode can be easily identified, and the fuel cell When assembling the separator, it is possible to prevent a mistake that the front and back surfaces of the separator are mistakenly attached, and the productivity of the fuel cell is improved. In addition, by properly attaching the separator, a configuration corresponding to the difference in reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be sufficiently extracted.

  According to the fuel cell separator of the present invention, the front and back surfaces of the separator have a geometrically asymmetric shape, so that the front and back surfaces of the separator can be easily identified. It is possible to prevent the mistake of attaching the fuel cell by mistake, and the productivity of the fuel cell is improved. In addition, by properly attaching the separator, a configuration corresponding to the difference in reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be sufficiently extracted.

  FIG. 1 shows a fuel cell using a separator according to a first embodiment of the present invention. As shown in FIG. 1 (a), the fuel cell 1 includes a plurality of fuel cells 2 sandwiched between two pressing plates 5A and 5B, and the fuel cells 2 are fastened by a fastening rod 6. is there.

  As shown in FIG. 1B, the fuel battery cell 2 includes a solid polymer electrolyte membrane (not shown), an anode 11 disposed on one side of the solid polymer electrolyte membrane, and another solid polymer electrolyte membrane. A cathode 12 disposed on the side surface, a fuel gas passage 13 for supplying fuel gas to the surface in contact with the anode 11, and an oxidizing gas passage 14 for supplying oxidizing gas to the surface in contact with the cathode 12 are formed. Separator 7. A notch 10 is formed at one corner of the fuel cell 2. Here, the separator 7 has a different shape or cross-sectional shape on the anode 11 side and the cathode 12 side. For example, the oxidizing gas channel 14 is formed larger than the fuel gas channel 13.

  The holding plate 5 </ b> A includes a fuel gas introduction pipe 3 </ b> A for introducing the fuel gas into the separator 7, a fuel gas discharge pipe 3 </ b> B for discharging the fuel gas from the separator 7, and an oxidizing gas for introducing the oxidizing gas into the separator 7. An introduction pipe 4A and an oxidizing gas discharge pipe 4B for discharging the oxidizing gas from the separator 7 are formed. The presser plate 5A fastens the plurality of fuel cells 2 with the fastening rod 6 between the presser plate 5B.

  FIG. 2 shows a separator according to the first embodiment of the present invention. The separator 7 has a fuel gas channel groove 9 and an oxidizing gas channel on both sides of a central portion of a stainless steel plate (for example, 50 mm long × 50 mm wide × 0.2 mm thick) having a rectangular shape in plan view. A groove 9a is provided. A fuel gas inlet side manifold hole 7a for supplying fuel gas around the grooves 9, 9a, a fuel gas outlet side manifold hole 7b for discharging fuel gas, and an oxidizing gas inlet side manifold hole for supplying oxidizing gas 8a and an oxidizing gas outlet side manifold hole 8b for discharging oxidizing gas. The fuel gas channel groove 9 and the oxidizing gas channel groove 9a are, for example, 15 mm wide and 3 mm deep, and are formed so that the grooves 9 and 9a are parallel to each other at intervals of 5 mm. As shown in FIG. 2, the separator 7 cuts off a part of the corner at the same site when viewed from the anode 11 or the cathode 12, and as an identification part for identifying the surface in contact with the anode 11 and the surface in contact with the cathode 12. The notch 10 is formed so as to have a geometrically asymmetric shape when viewed from the anode 11 or the cathode 12.

  When the fuel cell 1 is manufactured, as shown in FIG. 1B, the fuel cell 1 is assembled so that the separator 7 is sandwiched between the anode 11 and the cathode 12 between the adjacent fuel cells 2. At this time, the separator 7 is arranged so that the notch 10 is positioned at the lower right corner in FIG. By arranging in this way, all the separators 7 are in a state where the surface in contact with the anode 11 and the surface in contact with the cathode 12 are correctly arranged.

  The function of the fuel cell 1 will be described. When fuel gas (hydrogen gas) is introduced into the fuel gas flow path 13 from the fuel gas introduction pipe 3A, the hydrogen gas flows through the fuel gas flow path 13 and is decomposed into hydrogen ions and electrons at the anode 11, and the hydrogen ions are solid polymer. It passes through the electrolyte membrane and moves to the cathode 12 side. The electrons move to the cathode 12 side via a load by a lead (not shown). On the other hand, when the oxidizing gas (air) is introduced from the oxidizing gas introduction pipe 4A into the oxidizing gas channel 14 at the cathode 12, oxygen in the oxidizing gas flowing through the oxidizing gas channel 14 passes through the load. It reacts with the electrons that have moved and the hydrogen ions that have moved from the anode 11 side to produce water. Thus, electricity can be taken out by creating a flow of electrons through the electrode reaction.

  According to the separator 7 of the present embodiment, when the fuel cell is manufactured by assembling the separator 7, the surface that contacts the anode 11 and the surface that contacts the cathode 12 of the separator 7 are aligned by aligning the notch 10. Therefore, if assembled in that order, the surface in contact with the anode 11 and the surface in contact with the cathode 12 are not mistaken, and the productivity of the fuel cell is improved. In addition, since the surface in contact with the anode 11 and the surface in contact with the cathode 12 are correctly attached, the structure corresponding to the difference in the reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be fully extracted. In addition, if a non-oxidized film is formed on the oxidizing gas flow path side, it will be used, so that the conductivity decreases due to the formation of an oxide film on the surface in contact with the cathode and the performance of the fuel cell. It is possible to prevent the deterioration and to fully draw out the performance of the fuel cell.

  FIG. 3 shows a separator according to the second embodiment of the present invention. This separator 7A is different from the separator 7 according to the first embodiment of the present invention in that an arcuate portion 10A in which the curvature of one corner of the separator 7A is changed is formed. According to the separator 7A of the present embodiment, when the fuel cell is manufactured by assembling the separator 7A, the surface in contact with the anode 11 and the surface in contact with the cathode 12 of the separator 7A are aligned by aligning the arc-shaped portion 10A. Therefore, when attaching the separator 7A, the front and back are not mistaken, and the productivity of the fuel cell is improved. In addition, since the surface in contact with the anode 11 and the surface in contact with the cathode 12 are correctly attached, the structure corresponding to the difference in the reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be fully extracted. In addition, if a non-oxidized film is formed on the oxidizing gas flow path side, it will be used, so that the conductivity decreases due to the formation of an oxide film on the surface in contact with the cathode and the performance of the fuel cell. It is possible to prevent the deterioration and to fully draw out the performance of the fuel cell.

  FIG. 4 shows a separator according to the third embodiment of the present invention. This separator 7B is different from the separator 7 according to the first embodiment of the present invention in that a protruding portion 10B is formed on one side of the separator 7B. According to the separator 7B of the present embodiment, when the fuel cell is manufactured by assembling the separator 7B, the surface that contacts the anode 11 of the separator 7B and the cathode are aligned by aligning the separator 7B so that the protruding portion 10B is at the same position. Since the surface in contact with 12 is arranged in alignment, there is no mistake in the front and back when the separator 7B is attached, and the productivity of the fuel cell is improved. In addition, since the surface in contact with the anode 11 and the surface in contact with the cathode 12 are correctly attached, the structure corresponding to the difference in the reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be fully extracted. In addition, if a non-oxidized film is formed on the oxidizing gas flow path side, it will be used, so that the conductivity decreases due to the formation of an oxide film on the surface in contact with the cathode and the performance of the fuel cell. It is possible to prevent the deterioration and to fully draw out the performance of the fuel cell.

  FIG. 5 shows a separator according to a fourth embodiment of the present invention. This separator 7C is different from the separator 7 according to the first embodiment of the present invention in that a narrow groove 10C is formed on one surface of the separator 7C. According to the separator 7C of the present embodiment, when the fuel cell is manufactured by assembling the separator 7C, for example, by aligning the separator 7C so that the narrow groove 10C is positioned on the upper surface of the separator 7C, the anode 7 of the separator 7C is provided. Since the surface in contact with the surface in contact with the cathode 12 is arranged in alignment, there is no mistake in the front and back when the separator 7C is attached, and the productivity of the fuel cell is improved. In addition, since the surface in contact with the anode 11 and the surface in contact with the cathode 12 are correctly attached, the structure corresponding to the difference in the reaction efficiency between the fuel gas and the oxidizing gas can be obtained, and the performance of the fuel cell can be fully extracted. In addition, if a non-oxidized film is formed on the oxidizing gas flow path side, it will be used, so that the conductivity decreases due to the formation of an oxide film on the surface in contact with the cathode and the performance of the fuel cell. It is possible to prevent the deterioration and to fully draw out the performance of the fuel cell.

  The separator of the present invention can be applied to separators of any material regardless of the material of the separator. In the separator of the present invention, an identification part such as a notch is formed from the direction of the separator as viewed from the anode or the cathode. However, as long as the identification part can be recognized from other surfaces, the identification part is formed at any part. May be. For example, a thin plate-like portion such as a side surface of the separator may be colored or a groove may be formed. Further, cooling may be performed by introducing cooling water into the separator. Further, if the identification unit can be identified magnetically and optically rather than visually, automatic assembly can be performed, and product productivity is further improved.

It is a figure which shows the fuel cell using the separator which concerns on the 1st Embodiment of this invention. (A) is a perspective view of a fuel cell, (b) is an enlarged sectional view of a main part of a fuel cell. It is a figure which shows the separator which concerns on the 1st Embodiment of this invention. It is a figure which shows the separator which concerns on the 2nd Embodiment of this invention. It is a figure which shows the separator which concerns on the 3rd Embodiment of this invention. It is a figure which shows the separator which concerns on the 4th Embodiment of this invention. It is a figure which shows the conventional fuel cell. It is a disassembled perspective view of the fuel cell in the conventional fuel cell. It is a center cross-sectional view of the conventional separator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Fuel cell 3A Fuel gas introduction pipe 3B Fuel gas discharge pipe 4A Oxidative gas introduction pipe 4B Oxidative gas discharge pipe 5A, 5B Holding plate 6 Tightening rod rod 7, 7A, 7B, 7C Separator 7a Fuel gas inlet Side manifold hole 7b Fuel gas outlet side manifold hole 8a Oxidizing gas inlet side manifold hole 8b Oxidizing gas outlet side manifold hole 9 Fuel gas channel groove 9a Oxidative gas channel groove 10 Fuel cell 10A Arc-shaped portion 10B Projection Part 10C Narrow groove 11 Anode 12 Cathode 13 Fuel gas channel 14 Oxidizing gas channel 20 Fuel cell 21 Fuel cell 22 Solid polymer electrolyte membrane 23 Anode 24 Cathode 25 Separator 25a Fuel gas channel 25b Oxidizing gas channel 26 Positive electrode 27 Negative electrode

Claims (3)

In the fuel cell separator disposed between the anode and the cathode,
A first surface which is located on the anode side and forms a flow path of a first reaction gas between the anode and the anode;
A second surface that is located on the cathode side and forms a flow path of a second reaction gas between the cathode and the cathode;
A fuel cell separator, comprising: an identification unit that identifies the first surface and the second surface.   The fuel cell separator according to claim 1, wherein the identification unit visually identifies the shape. The fuel cell separator according to claim 1, wherein the first surface and the second surface have a geometrically asymmetric shape.

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