JP2006309964A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell enable enhancing of a cooling efficiency and thinning of a cell to be compatible with each other while cut-off of a cooling medium for cooling the cell and gas is ensured. <P>SOLUTION: A first plate 25 forms an oxidant gas passage in a unit cell by projecting many lines of bridge-shaped projections 32 from a flat plate substrate 30, and bringing the projections 32 into contact with a gas diffusion layer on the surface of an electrolyte layer. A second plate 27 connected to the first plate 25 has many lines of long-hole-shaped openings 55a-55f blanked and pressed in the lateral direction. When both plates are connected, the openings 55a-55f of the second plate 27 are laid on a passing opening 44 of the first plate 25 at both ends, and blocked by the first plate 25 on the back surface of the substrate 30 of the first plate 25. The blocked openings 55a-55f form a passage of water which is a cooling medium. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell that performs gas supply and cooling with a cooling medium on an electrolyte layer having a catalyst layer on the surface.

  A fuel cell generally has a single cell stack structure, and a single cell sandwiches a MEA (Membrance Electrode Assembly) composed of an electrolyte layer that forms a catalyst layer on the surface thereof with a gas flow path forming member for fuel gas and oxidizing gas. To do. In recent years, such a gas flow path forming member has been thinned by using a metal plate (see, for example, Patent Document 1).

JP 2002-18422 A

  In the fuel cell proposed in this patent document, a metal plate having unevenness is joined to a flat carbon plate, but there is a lack of measures for cooling the battery. In general, since battery cooling is performed by flowing a cooling medium such as water, it is necessary to form a flow path for such a cooling medium. When providing the cooling medium flow path in the fuel cell of the above-mentioned document, it is easy to form a groove for the flow path in the carbon plate or separately prepare another member having the cooling medium flow path.

  However, the cooling medium flow path needs to be formed so that the cooling medium does not come into contact with the fuel gas or oxidizing gas supplied to the MEA. Groove machining is required on the side. In this case, the cooling medium flowing through the cooling medium flow path exhibits a cooling function for the metal plate via the carbon plate on the bottom surface of the groove, so that the cooling efficiency is lowered by the amount corresponding to the bottom surface of the groove. On the other hand, when another member having a cooling medium flow path is separately prepared, the thickness is increased by providing the member.

  The present invention is made in order to solve the above-mentioned problems when a metal plate is used for gas supply, and it is possible to improve the cooling efficiency and reduce the thickness of the battery while ensuring the insulation between the cooling medium and the gas for cooling the battery. Its purpose is to achieve both.

  In order to solve at least a part of such problems, in the fuel cell of the present invention, when supplying the gas to the electrolyte layer having a catalyst layer on the surface and cooling with a cooling medium, the fuel cell is made of a metal located on the electrolyte layer side. The first plate and a metal second plate joined to the first plate are used. The first plate includes a plurality of protrusions, and the gas flow paths are formed on the main surface side of the electrolyte layer by positioning the protrusions on the electrolyte layer side. The second plate is joined to the first plate on the surface opposite to the projection forming surface of the first plate, so that the cooling flow path through which the cooling medium passes is blocked by the plate surface of the first plate. In this way, it is formed.

  Therefore, the cooling medium flowing through the cooling flow path is not in contact with the gas flowing through the gas flow path because the cooling flow path is blocked by the first plate on the gas flow path side, and the cooling medium and the gas The interruption is surely ensured. In addition, since the cooling medium directly contacts the first plate and exhibits the battery cooling function, the cooling efficiency can be increased. In addition, since it is only necessary to block the cooling flow path of the second plate with the first plate to be joined to the second plate, a separate member for cooling is not required, and the battery can be thinned.

  In the fuel cell of the present invention described above, the first plate is provided in multiple rows as a bridge-like protrusion through which the protrusion side wall penetrates, and the cooling flow path of the second plate is provided on the bridge-like protrusion. It is also possible to overlap between columns. In this aspect, since the gas can pass through the side wall of the bridge-like protrusion, in the gas flow path formed on the main surface side of the electrolyte layer, it is possible to suppress the gas from colliding with the protrusion and turbulence in the flow. , Can improve power generation performance.

  Further, the first plate may be provided in multiple rows as closed projections with the projections closed by the projection side walls, and the cooling flow path of the second plate may overlap the closed projection rows. . In this case, the cooling medium having the cooling flow path is preferable because the cooling efficiency of the cooling medium is increased because the cooling of the electrolyte layer is performed through the closed projections located on the electrolyte layer side. At this time, if the closed projection has a gap inside the projection, the cooling medium enters the inside of the closed projection, which is preferable because the cooling efficiency by the cooling medium is further increased.

  If such a cooling channel in the second plate is used as a punching hole in the second plate, it is not only easy to form, but it is possible to further reduce the thickness, which is preferable.

In addition, the present invention is a fuel cell in which a single cell including an electrolyte layer having a catalyst layer on the surface is laminated,
Each of the single cells
A plurality of protrusions are provided, and the protrusions are positioned on the side of the electrolyte layer so that a first metal plate that forms a gas flow path for gas supply on the main surface side of the electrolyte layer is formed on both sides of the electrolyte. Prepared,
Between adjacent single cells,
A metal plate joined to and sandwiched by the first plate for each single cell, wherein the first plate has a cooling flow path through which the cooling medium passes by joining to the first plate on both sides. A second plate formed so as to be blocked by the plate surface of
The second plate may include the cooling channel as a punched hole.

  In this way, the second plate between the single cells becomes a substitute for the existing separator that has been incorporated only to divide the single cells, so that no separator is required, and the configuration is simplified accordingly. Thinning can be achieved.

Moreover, this invention is provided with the following procedures as a manufacturing method of a fuel cell. That is, a fuel cell manufacturing method for performing gas supply and cooling with a cooling medium on an electrolyte layer having a catalyst layer on its surface,
(A) preparing a metal first plate having a plurality of protrusions;
(B) a step of preparing a second plate that is a metal plate and has punched holes in multiple rows;
(C) The first plate on both sides of the electrolyte layer so that the projection of the first plate is positioned on the electrolyte layer side and a gas flow path for gas supply is formed on the main surface side of the electrolyte layer. A step of arranging
(D) The second plate is formed by closing the punched hole of the second plate with the plate surface of the first plate so as to form the closed punched hole as a cooling channel through which the cooling medium passes. Joining the first plate to the first plate.

  According to the manufacturing method of the present invention, it is possible to easily manufacture a fuel cell capable of reliably shutting off the cooling medium and gas, improving the cooling efficiency, and reducing the battery thickness.

  In preparing the first plate, opposing slits can be formed at predetermined positions on the flat metal plate, and a plurality of protrusions can be formed by pressing the slits with a convex mold. In this way, the first plate can be produced by a simple technique called press working, which is convenient.

  Embodiments of the present invention will be described below with reference to the drawings. The fuel cell according to the embodiment of the present invention is a polymer electrolyte fuel cell and has a stack structure in which a plurality of single cells are stacked. FIG. 1 is a schematic cross-sectional view showing an outline of the configuration of a single cell 20 constituting the fuel cell of the embodiment. The unit cell 20 includes an electrolyte layer 21 having a catalyst layer (not shown) on the surface, gas diffusion layers 22 and 23 that sandwich the electrolyte layer 21 from both sides to form a sandwich structure, and the sandwich structure further from both sides. First plates 25 and 26 for forming gas flow paths to be sandwiched, and second plates 27 and 28 disposed on the outside thereof are provided.

  The electrolyte layer 21 is a proton conductive ion exchange membrane formed of a solid polymer material such as a fluorine resin, and exhibits good electrical conductivity in a wet state. In this example, a Nafion membrane (manufactured by DuPont) was used. The catalyst layer formed on the electrolyte layer 21 includes a catalyst that promotes an electrochemical reaction, such as platinum or an alloy made of platinum and other metals. In order to form the catalyst layer, for example, carbon powder carrying platinum or an alloy made of platinum and another metal is prepared, and the carbon powder carrying the catalyst is dispersed in an appropriate organic solvent, and an electrolyte solution (for example, Aldrich) is formed. A paste may be prepared by adding an appropriate amount of Chemical, Nafion Solution). By applying this paste onto the electrolyte layer 21 by a method such as screen printing, a catalyst layer can be formed. Alternatively, a sheet containing a carbon powder carrying the catalyst is formed into a sheet, and a sheet is formed on the electrolyte layer 21 by pressing the sheet, or the paste is used as a gas diffusion layer 22, It is good also as applying to 23 side.

  The gas diffusion layers 22 and 23 are made of a member having gas permeability and electronic conductivity, and are formed of, for example, a metal member such as foam metal or metal mesh, or a carbon member such as carbon cloth or carbon paper. can do. Such gas diffusion layers 22 and 23 diffuse the gas used for the electrochemical reaction and collect current with the catalyst layer.

  The first plates 25 and 26 each form a space for a gas flow path on the principal surface side of the electrolyte layer on each side of the electrolyte layer 21. In this case, the first plate 25 disposed on the gas diffusion layer 22 side forms an in-single cell oxidizing gas flow path 25a through which an oxidizing gas containing oxygen passes. Further, the first plate 26 disposed on the gas diffusion layer 23 side forms a fuel cell channel 26a in the single cell through which a fuel gas containing hydrogen passes. Here, in the present embodiment, the first plates 25 and 26 are made of titanium. Titanium is a metal with excellent corrosion resistance, and is desirable as a constituent material of a member that forms a fuel gas channel in a single cell that provides a strong reducing atmosphere and an oxidizing gas channel in a single cell that provides a strong oxidizing atmosphere. If the durability is acceptable, plates of other types of metals such as stainless steel can be used as the first plates 25 and 26. Alternatively, the first plates 25 and 26 may be formed by forming a metal plate material into a predetermined shape and then providing a corrosion-resistant layer such as a noble metal layer on the surface. The structure of the first plates 25 and 26 and the state of flow path formation correspond to the main part of the present invention, and will be described in detail later.

  Since the second plates 27 and 28 are members that also function as separators in existing single cells, the second plates 27 and 28 are formed of a material having electron conductivity and have gas impermeability. For example, the second plate can be formed of a metal member such as stainless steel or a carbon member. The second plates 27 and 28 of the present embodiment are formed in a thin plate shape, and the surfaces in contact with the first plates 25 and 26 for gas flow path formation are flat surfaces without unevenness. For convenience of illustration, the second plates 27 and 28 are drawn thick, but, like the first plates 25 and 26, are only a few millimeters thick.

  In addition, in order to ensure the gas-sealing property in a member joining location, sealing members, such as a gasket, are suitably arrange | positioned between each member in the outer peripheral part of the single cell 20. FIG. In addition, a plurality of gas manifolds (not shown) are provided on the outer peripheral portion of the single cell 20 in parallel with the stacking direction of the single cells 20 and through which fuel gas or oxidizing gas flows. The fuel gas flowing through the fuel gas supply manifold among the plurality of gas manifolds is distributed to each single cell 20 and is supplied to the electrochemical reaction, and each single-cell fuel gas flow path 26a formed by the first plate 26 and It passes through the gas diffusion layer 23 and then collects in the fuel gas discharge manifold. Similarly, the oxidizing gas flowing through the oxidizing gas supply manifold is distributed to each single cell 20 and passes through the single-cell oxidizing gas flow path 25a and the gas diffusion layer 22 formed by the first plate 25 while being subjected to an electrochemical reaction. After that, it collects in the oxidizing gas discharge manifold.

In the single cell 20 shown in FIG. 1, the flow direction of the fuel gas (H ₂ ) / oxidizing gas (O ₂ ) is the same in the single-cell fuel gas channel 26a and the single-cell oxidizing gas channel 25a. This is because the left and right first plates 25 and 26 of the electrolyte layer 21 are the same. However, the flow directions of the two gases may flow in different directions such as the reverse direction and the orthogonal direction in addition to the same direction described above. When the flow of both gases is reversed, the cross-sectional structure of the single cell 20 is the same as in FIG. 1, but in the single cell where both gases are flowed orthogonally, the first plates 25 on the left and right sides of the electrolyte 26, since a state of formation of a convex portion 32 to be described later is different, a single cell section in this case will be described later.

  As the fuel gas supplied to the fuel cell, a hydrogen-rich gas obtained by reforming a hydrocarbon-based fuel may be used, or a high-purity hydrogen gas may be used. For example, air can be used as the oxidizing gas supplied to the fuel cell.

  Next, the first plates 25 and 26 and the second plates 27 and 28 will be described. FIG. 2 is a perspective view schematically showing the first plate 25 and the second plate 27 in a partially enlarged manner while being partially enlarged. Since the first plate 26 and the second plate 27 have the same structure as the first plate 25 and the second plate 28, the first plate 25 and the second plate 27 will be described below.

  As shown in FIG. 2, the first plate 25 includes a flat substrate portion 30 and a plurality of convex portions 32 provided to protrude from the substrate portion 30. The convex portions 32 are formed in a trapezoidal shape so as to protrude from the substrate portion 30 and are arranged in multiple rows, and are arranged in a so-called staggered pattern in each row. Further, since the convex portion 32 has a bridge shape penetrating the side wall in the vertical direction in FIG. 2, the opening 31 is left in the substrate portion 30. The first plate 25 has the top surfaces of the bridge-shaped convex portions 32 arranged in multiple rows positioned on the electrolyte layer 21 side, and specifically contacts the gas diffusion layer 22 (see FIG. 1). A space corresponding to the raised height of 32 is formed as the oxidizing gas flow path 25a in the single cell. In this case, since the convex portion 32 has a bridge shape as described above, gas flows on the back side of the convex portion 32 as indicated by an arrow in the figure.

  In addition, the first plate 25 includes an oxidant gas inflow opening 40, an oxidant gas discharge opening 41, and fuel gas passage openings 42 and 43 at the upper and lower peripheral edges of the plate. The water passage opening 44 is provided. The oxidant gas inflow opening 40 and the discharge opening 41 are arranged diagonally up and down so that the gas flow in the oxidant gas flow path 25a in the single cell is not significantly biased. That is, the gas (oxidizing gas) flowing in from the inflow opening 40 becomes a large number of diverted flows as shown by arrows in the figure, and passes through the single-cell in-cell oxidizing gas channel 25a, and is discharged from the discharge opening 41. The In this way, while flowing in the single-cell oxidizing gas flow path 25a, the oxidizing gas diffuses in the gas diffusion layer 22 and is supplied to the electrolyte layer 21, more specifically to the catalyst layer on the surface thereof. The gas discharged from the discharge opening 41 is collected by a manifold (not shown) and carried out of the cell.

  When the fuel cell generates power, the oxidizing gas is supplied and discharged through the gas diffusion layer 22 between the oxidizing gas flow path 25a in the single cell and the catalyst layer. In addition, when the fuel cell generates power, water is generated on the catalyst layer on the cathode side as the electrochemical reaction proceeds. In this embodiment, in the single cell from the catalyst layer through the gas diffusion layer 22. The generated water is discharged to the oxidizing gas channel 25a. Similarly, in the single-cell fuel gas flow path 26a, fuel gas is supplied to and discharged from the catalyst layer.

  The passage openings 42 and 43 are for flowing the fuel gas into the fuel gas flow path 26a in the single cell in the adjacent single cell 20, and are formed diagonally like the inflow opening 40 and the discharge opening 41 for the oxidizing gas. ing. The passage openings 44 are formed so as to be positioned between the rows and above the uppermost row and below the lowermost row so as not to interfere with the row of the raised portions 32 when the convex portions 32 are viewed as horizontal rows. ing.

  The first plate 25 of the present embodiment is produced by a series of press working on a single metal plate member. FIG. 3 is a procedure flow showing a manufacturing process of the first plate 25, and FIG. 4 is an explanatory diagram for explaining a state of manufacturing the first plate 25. In producing the first plate 25, as shown in FIG. 3, a steel plate is prepared (step S100). This steel plate has the same thickness as the first plate 25. Next, the slit 35 is formed on the steel plate so as to face the formation position of the convex portion 32 described above by laser processing, shearing processing, or the like (step S110). FIG. 4 shows the formed slits 35 in the first plate 25 (substrate part 30). The square shearing (cutting) of the first plate 25 (substrate part 30) is the last to be described later in order to improve production efficiency. Since it is performed in the process, the slit 35 is formed in the state of a steel plate in step S110.

  After the slit formation, a press piece 46 having a press protrusion 45 having a trapezoidal cross section as shown in FIG. 4 and an opening punching press piece (not shown) are pressed against the steel plate (step S120). At this time, the press piece 46 presses the press protrusion 45 in conformity with the formation position of the slit 35 (between the slits). If it does so, the location between the slits 35 will protrude from the circumference | surroundings, and the convex part 32 which followed the convex shape of the press protrusion 45 will be formed in multiple rows. The openings such as the discharge opening 41 are formed by a punching press piece in parallel with the formation of the convex portion 32 or before and after the formation of the convex portion 32.

  Next, the steel plate is sheared (cut) into the square shape of the first plate 25 (substrate portion 30), that is, the shape shown in FIG. 4 so as to include the convex portion 32, the discharge opening 41, and the like (step S130). If it carries out like this, the 1st plate 25 of several sheets can be produced efficiently from the steel plate of a standard size. It is also possible to prepare the first plate 25 by preparing the rectangular substrate portion 30 (first plate 25) first and slitting / pressing the substrate portions 30 one by one.

  The second plate 27 includes openings 50 to 53 (see FIG. 5 for the opening 53) that match the inflow opening 40, the discharge opening 41, and the passage openings 42 and 43 of the first plate 25 to be joined. , The gas passage opening through the matching opening. For example, the opening 50 is an oxidizing gas passage opening before the inflow opening 40. In addition, the second plate 27 includes elongated holes 55a to 55f that are punched in the horizontal direction and arranged in multiple rows. The openings 55a to 55f are formed so that the opening ends thereof coincide with the passage openings 44 that the first plate 25 has in multiple rows on the left and right.

  The second plate 27 is manufactured in the order of preparation of a steel plate (step S100), pressing press (step S120), and square-shaped shearing (step S130) by taking almost the same process as the first plate 25 described above. At the time of this pressing, press pieces for punching the openings 50 to 53 and the openings 55a to 55f are used.

  Next, usage states of the first plate 25 and the second plate 27 having the above-described configuration will be described. 5 is a perspective view showing a state in which the first plate 25 and the second plate 27 are joined, FIG. 6 is a schematic sectional view taken along line 6-6 of FIG. 5, and FIG. 7 is a line 7-7 of FIG. FIG. 8 is a schematic cross-sectional view taken along the line 8-8 bent along the formation portion of the convex portion 32 in FIG. As shown in the drawing, when both plates are joined, the inflow opening 40 and the opening 50, the passage opening 42 and the opening 52, the passage opening 43 and the opening 53, and the discharge opening 41 and the opening 51 overlap each other. Further, the openings 55 a to 55 f of the second plate 27 overlap with the passage openings 44 of the first plate 25 at both ends thereof. In addition, a gasket (not shown) is disposed at the overlapping portion of these openings to ensure gas sealing properties and water tightness.

  In this case, in the first plate 25, the passage openings 44 are located between the rows and at the upper and lower portions of the rows so as not to interfere with the rows of the convex portions 32 in the lateral direction, as described above, and therefore match this. Even in each of the openings 55 a to 55 f of the second plate 27, it is positioned above and below each row / row of the convex portion 32. These openings 55 a to 55 f are closed on the first plate 25 side on the back surface of the substrate portion 30 of the first plate 25.

  On the other hand, the horizontal rows to which the convex portions 32 of the first plate 25 belong are located between the openings 55 a to 55 f in the second plate 27, so that the convex portions 32 are formed to remain on the substrate portion 30. Each opening 31 is closed by the second plate 27.

  As described above, in the fuel cell (unit cell 20) of the present embodiment having the above-described configuration, water is poured from one of the left and right passage openings 44 of the first plate 25, and is closed as described above. The openings 55a to 55f of the plate 27 can be used as the water flow paths. The water that is the cooling medium that passes through the openings 55a to 55f is blocked by the first plate 25 (specifically, the substrate portion 30). There is no contact with the oxidizing gas flowing through the oxidizing gas channel 25a in the single cell formed in the above manner. Even in the openings 31 corresponding to the respective protrusions 32, the second plate 27 closes the openings 31 as described above. Therefore, the openings 31 and the oxidant gas flow paths 25a in the single cell and the openings are opened. 55a-55f does not communicate. As a result, even if the first plate 25 and the second plate 27 are joined and the openings 55a to 55f as cooling channels are formed in the second plate 27, the water and the oxidizing gas as the cooling medium are blocked. It can be surely secured.

  In addition, in this embodiment, the water (cooling medium) flowing through the openings 55a to 55f of the second plate 27 is in direct contact with the first plate 25 (substrate part 30) that closes these openings, and the gas diffusion layer is interposed through the plate. 22 and the electrolyte layer 21 are cooled, so that the battery can be cooled with high cooling efficiency. In addition, such a cooling structure can be achieved by closing the openings 55a to 55f of the second plate 27 with the first plate 25 to which the second plate 27 is to be joined. Therefore, it is possible to reduce the thickness and weight of the fuel cell having a single cell stacked structure.

  Moreover, in the present Example, the convex part 32 was made into bridge | bridging shape so that gas could pass from a protruding side surface also on the convex part back surface side. Therefore, as shown in FIG. 2, in the gas flow path in the single cell (the oxidation gas flow path 25a in the single cell / the fuel gas flow path 26a in the single cell), the gas is divided into a plurality of lines and flows into the single cell The gas can be flowed to the gas flow path so that the gas does not collide with the peripheral wall of the convex portion 32 and the flow is not significantly disturbed. That is, since it is possible to make it difficult for the flow to intersect the shunt flow, diffusion to the gas diffusion layer (gas supply / discharge) becomes more uniform and power generation performance can be improved.

  In the above-described embodiment, the arrangement of the convex portions 32 of the first plate 25 is a horizontal row, and the openings 55a to 55f of the second plate 27 are positioned between and above the row. It is not limited to this. FIG. 9 is a schematic perspective view of a modified example showing the first plate 25 and the second plate 27 in a case where the convex portions 32 are present in a curved line to the left and right.

  As shown in the figure, in this modified example, in the first plate 25, the convex portions 32 are scattered along a curved locus 32L indicated by a dotted line in the drawing. In this case, the second plate 27 includes openings 56a to 56e so as to be positioned between the curved trajectory 32L and the curved trajectory 32L illustrated and outside the curved trajectory 32L. The openings 56a to 56e have a curved locus that is the same as the dotted locus (curved locus 32L) of the convex portion 32, and are connected to adjacent openings at the top and bottom of the plate.

  The opening 56e is overlapped with the passage opening 44 of the first plate 25 at one end side (upper end side) thereof, and the opening 56a is overlapped with the passage opening 44 of the first plate 25 at a diagonal position of the plate. ing. Even in this case, the connection opening portion of the opening adjacent to the openings 56a to 56e of the curved locus is blocked by the first plate 25 to be joined to the second plate 27, and in the same manner as the openings 55a to 55f described above, It becomes a flow path of water which is a cooling medium. Therefore, even in the modification shown in FIG. 9, the same effects as those of the above-described embodiment can be obtained.

  In addition, the arrangement of the convex portions 32 is staggered, but the convex portions 32 may be arranged in the same manner in each row. FIG. 10 is a schematic perspective view of a first plate 25 and a second plate 27 showing a modified example in which the convex portions 32 are arranged vertically and horizontally, and FIG. 11 is a first plate showing another modified example in which the convex portions 32 are arranged vertically and horizontally. 25 is a schematic perspective view of the second plate 27 and the second plate 27. FIG.

  In the modification shown in FIG. 10, the configuration of the first plate 25 and the second plate 27 is as shown in FIG. 2 except that the convex portions 32 are arranged in the first plate 25 in the vertical and horizontal directions. That is, the second plate 27 is provided with openings 55 a to 55 f between the rows and above and below the rows, assuming that the convex portions 32 of the first plate 25 are arranged in the horizontal direction, and these openings are closed by the first plate 25 and cooled. A flow path of water as a medium is used.

  In the modification of FIG. 11, the arrangement of the protrusions 32 in the first plate 25 is the same as that in FIG. 9, and the second plate 27 assumes that the protrusions 32 of the first plate 25 are arranged in the vertical direction. Opening 57a-57f is provided in the right and left of a row | line | column, and these opening is connected by the opening adjacent to the plate upper and lower sides. The second plate 27 is joined to the first plate 25 so that the first plate 25 closes the openings 57a to 57f and the connecting openings of the adjacent openings to form a flow path of water as a cooling medium. . In this case, the passage openings 44 diagonally formed by the first plate 25 overlap the openings 57 a and 57 f at both ends of the second plate 27 at the opening end portions.

  Even in both of the above-described modifications, the same effects as those of the above-described embodiments can be obtained.

  Next, another modification will be described. FIG. 12 is a schematic perspective view of the first plate 25 and the second plate 27 in a modified example in which the convex portion 32 is formed as a closed projection in which the raised side wall is blocked, and FIG. 13 is taken along the line 13-13 in FIG. It is a schematic sectional drawing.

  In this modification, the convex part 32 is a closed projection protruding from the first plate 25 (substrate part 30) in a closed state, and the openings 55a to 55e in the second plate 27 are arranged in the horizontal direction. ) Is characterized by overlapping. In this case, although the convex portions 32 are arranged in the vertical and horizontal directions in the drawing, the closed convex portions 32 may be arranged in a staggered manner in the horizontal rows. The convex portion 32 has a spherical bulge at the tip, but may have various shapes such as a truncated cone shape and a truncated pyramid shape with closed side surfaces as long as the shape is closed.

  In this modification, the openings 55a to 55e of the second plate 27 are closed by the first plate 25 (substrate part 30) as in the previous embodiment, but the rows of these openings and the protrusions 32 overlap. Therefore, the openings 55a to 55e are blocked by the closed convex portion 32 in addition to the flat substrate portion 30 on the first plate 25 side. For this reason, the water that is the cooling medium passing through the openings 55 a to 55 e of the second plate 27 enters the back surface recess 32 a (see FIG. 13) of the convex portion 32. Since the convex portion 32 is in contact with the gas diffusion layer 22 and, in turn, the electrolyte layer 21 at the top thereof, the water that is the cooling medium passing through the openings 55a to 55e of the second plate 27 is the convex portion 32. Since the electrolyte layer 21 and the like are cooled from the back side through the cooling, the cooling efficiency is further increased, which is preferable in terms of maintaining battery performance. On the plate end side, the gasket 60 allows the passage opening 44 of the first plate 25 and the opening 55a of the second plate 27 to be sealed with the oxidant gas flow path 25a in the single cell, thereby forming the gasket 60. Water passes through the passage opening 44 and the opening 55a through a flow path (not shown).

  In the modification shown in FIG. 12, the openings 55a to 55e can be formed in the arrangement of the vertical openings (openings 57a and the like) as shown in FIG. Further, the present invention is not limited to vertical and horizontal but can be modified as follows. FIG. 14 is an explanatory view showing a modification of the state of forming the opening of the second plate 27 when the closed convex portion 32 is used.

  In FIG. 14, in the drawing, dotted points indicate the locations where the closed projections 32 included in the first plate 25 joined to the second plate 27 and the locations where the passage openings 44 are formed. The second plate 27 is provided with openings 58a to 58j so that the protrusions 32 are aligned in an oblique direction, and the openings 58a to 58e are connected by an opening 59a on the upper end side of the plate, so that the openings 58f ˜58j are connected by an opening 59b on the lower end side of the plate. In this case, the passage opening 44 of the first plate 25 that overlaps the opening 58a at the plate end serves as an inlet for water that is a cooling medium, and the passage opening 44 that overlaps the openings 58b to 58e at the plate end serves as an outlet for water. . The same applies to the openings 58f to 58j. Thus, even if it is a modification using the 2nd plate 27 which has the opening 58a-58j diagonally, the effect similar to the modification shown in FIG. 12 can be show | played.

  Here, taking the unit cell 20 shown in FIG. 1 as an example, the end configuration and the stack configuration of the fuel cell having the unit cell will be described. FIG. 15 is an explanatory view showing a state in which a fuel cell is configured by a single unit cell 20, and FIG. 16 is an explanatory view showing a state in which a fuel cell is configured by stacking unit cells 20.

  As shown in FIG. 15, the single-cell 20 single fuel cell has a configuration in which a flat terminal 29 is joined to the outside of the second plates 27 and 28. In this fuel cell, the openings 55 a to 55 f of the second plates 27 and 28 are closed by the terminal 29 and the first plates 25 and 26 on the battery outer shell side on both sides thereof. As shown in FIG. 16, in the stack structure in which a plurality of single cells 20 are stacked, one second plate 27 is interposed between adjacent single cells 20. As described above, the cooling flow path (opening 55a and the like) is formed by being closed by the first and second first plates 25. Therefore, a flat plate separator that separates the single cells 20 is not necessary, and the thickness and weight can be reduced accordingly. Moreover, since the common 2nd plate 27 which forms a cooling flow path exists only between adjacent single cells, the contact location of a member reduces that much. Therefore, the contact resistance can be reduced, which is beneficial in terms of battery performance.

  Next, the case where the flow directions of the fuel gas / oxidizing gas are orthogonal to each other will be described. FIG. 17 is a schematic cross-sectional view of a single cell of the fuel cell in which the flow directions of the fuel gas and the oxidizing gas are orthogonal to each other. FIG. It is a perspective view explaining a relationship.

  As shown in the figure, the first plate 25 and the second plate 27 have the above-described configuration. However, the first plate 26 includes the convex portions 32 so as to form a bridge shape in the upper and lower directions in the drawing. The two plates 28 have openings 70a to 70g extending in the vertical direction so that the convex portions 32 of the first plate 26 are arranged in the vertical direction in the drawing so as to be positioned between the rows. If the 2nd plate 28 is joined to this 1st plate 26, in the 2nd plate 28, opening 70a-70g block | closed with the 1st plate 26 will become the flow path of the water which is a cooling medium.

  And in the single cell 20 using each said plate, the direction of the convex part 32 differs in the 1st plates 25 and 26 so that it may show in figure. Therefore, on the first plate 25 side, the single-cell oxidizing gas flow path 25a is formed in the vertical flow direction in the figure, and on the first plate 26 side, the single-cell fuel gas flow path 26a faces the paper surface from the front. It is formed in the flow direction at the back or vice versa. In this case, the openings 70a to 70g extend in the vertical direction in the figure and are blocked by the first plate 26 over the range.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and embodiments, and can of course be implemented in various modes without departing from the gist of the present invention. is there. For example, in the above-described embodiments and modifications thereof, the first plate 25, 26 having the convex portion 32 for forming the gas flow path in the single cell (oxidation gas flow path / fuel gas flow path) and the catalyst layer are provided. Although the gas diffusion layer is provided in the structure, it is possible to adopt a configuration in which the gas diffusion layer is not provided. Here, the gas diffusion layer is usually formed of a member that is softer than the first plate 25 (the hardness of the constituent material is low, or the compression elastic modulus as the member is high), in order to improve the current collecting performance in the fuel cell. It is a member. That is, since the gas diffusion layer is a member that can ensure a larger contact area with the catalyst layer than the first plate 25, the catalyst layer and the first plate 25 (specifically, the top surface of the convex portion 32). The current collecting property can be improved. However, if the current collecting property is within an allowable range, the first plate 25 (specifically, the top surface of the convex portion 32) may be brought into direct contact with the catalyst layer without providing the gas diffusion layer.

  In addition, although the first plate 25 having the convex portion 32 and the second plate 27 whose flow path is blocked by the first plate 25 are provided in the polymer electrolyte fuel cell, they are applied to different types of fuel cells. It is also possible to do. Even with other types of fuel cells, both a high battery cooling function and a thin battery can be achieved.

  15 and 16, the single cell 20 has the bridge-like convex portion 32, but the first plates 25 and 26 having the closed convex portion 32 (see FIGS. 12 and 13) are used. It can also be done. Further, in FIG. 15 and FIG. 16, the single cell 20 has a convex portion 32 in which the left and right second plates 27 and 28 of the electrolyte layer 21 are perpendicular to the gas flow (see FIGS. 17 and 18). It can also be.

It is a cross-sectional schematic diagram showing the outline of the structure of the single cell 20 which comprises the fuel cell of an Example. It is the perspective view which disassembled and represented typically the 1st plate 25 and the 2nd plate 27 expanding partially. 3 is a procedure flow showing a manufacturing process of the first plate 25. It is explanatory drawing for demonstrating the mode of manufacture of the 1st plate. It is a perspective view showing the state where the 1st plate 25 and the 2nd plate 27 were joined. FIG. 6 is a schematic cross-sectional view taken along line 6-6 in FIG. It is a schematic sectional drawing in alignment with line 7-7 in FIG. It is a schematic sectional drawing in alignment with the 8-8 line | wire bent along the formation location of the convex part 32 in FIG. It is a schematic perspective view of the modification showing the 1st plate 25 and the 2nd plate 27 when it assumes that the convex part 32 exists in the arrangement | sequence curved left and right. FIG. 5 is a schematic perspective view of a first plate 25 and a second plate 27 showing a modification in which convex portions 32 are arranged vertically and horizontally. FIG. 9 is a schematic perspective view of a first plate 25 and a second plate 27 showing another modified example in which convex portions 32 are arranged vertically and horizontally. It is a schematic perspective view of the 1st plate 25 and the 2nd plate 27 in the modification which made the convex part 32 the obstruction | occlusion-like protrusion with which the protruding side wall was block | closed. It is a schematic sectional drawing in alignment with line 13-13 in FIG. It is explanatory drawing which shows the modification of the mode of formation of opening of the 2nd plate 27 at the time of using the block-shaped convex part 32. FIG. It is explanatory drawing which shows the mode in the case of comprising a fuel cell with the single unit cell 20. FIG. It is explanatory drawing which shows a mode at the time of laminating | stacking the single cell 20 and comprising a fuel cell. It is a schematic sectional drawing of the single cell of the fuel cell which made the flow direction of fuel gas and oxidizing gas orthogonal. FIG. 4 is a perspective view illustrating the relationship between the first plates 25 and 26 and the second plates 27 and 28, omitting the illustration of the electrolyte layer 21.

Explanation of symbols

20 ... single cell 21 ... electrolyte layer 22,23 ... gas diffusion layer 25,26 ... first plate 25a ... single cell oxidizing gas flow path 26a ... single cell fuel gas Flow path 27, 28 ... Second plate 29 ... Terminal 30 ... Substrate part 31 ... Opening 32 ... Convex part 32a ... Back side recess 32L ... Curved locus 35 ... Slit 40 ... Inflow opening 41 ... Discharge opening 42-44 ... Passing opening 45 ... Press projection 46 ... Press piece 50-53 ... Opening 55a-55f ... Opening 56a-56e ... Openings 57a-57f ... Openings 58a-58j ... Openings 59a, 59b ... Openings 60 ... Gaskets 70a-70g ... Openings

Claims (7)

A fuel cell that performs gas supply and cooling with a cooling medium on an electrolyte layer having a catalyst layer on its surface,
A first plate made of metal that includes a plurality of protrusions and forms a gas flow path for gas supply on the main surface side of the electrolyte layer by positioning the protrusions on the electrolyte layer side;
A metal second plate joined to the first plate,
The second plate is joined to the first plate on a surface opposite to the projection forming surface of the first plate, thereby providing a cooling flow path for allowing the cooling medium to pass through the plate surface of the first plate. A fuel cell that is formed so as to be blocked by a fuel cell. The fuel cell according to claim 1, wherein
The first plate comprises the protrusions in multiple rows as bridge-like protrusions through which the protrusion side walls pass,
The second plate includes the cooling flow path at a position overlapping the row of the bridge-like protrusions of the first plate. 2. The fuel cell according to claim 1, wherein the first plate includes the projections in multiple rows as closed projections in which projection sidewalls are closed,
The second plate includes the cooling flow path at a position overlapping the row of the closed projections of the first plate. A fuel cell according to any one of claims 1 to 3,
The second plate forms the cooling flow path with a punched hole. A fuel cell in which a single cell including an electrolyte layer having a catalyst layer on the surface is laminated,
Each of the single cells
A plurality of protrusions are provided, and the protrusions are positioned on the side of the electrolyte layer so that a first metal plate that forms a gas flow path for gas supply on the main surface side of the electrolyte layer is formed on both sides of the electrolyte. Prepared,
Between adjacent single cells,
A metal plate joined to and sandwiched by the first plate for each unit cell, and a cooling flow path through which the cooling medium passes by joining the first plate on both sides of the first plate. A second plate formed so as to be blocked by the plate surface of
The second plate includes the cooling channel as a punching hole. A fuel cell manufacturing method for performing gas supply and cooling with a cooling medium on an electrolyte layer having a catalyst layer on a surface,
(A) preparing a metal first plate having a plurality of protrusions;
(B) a step of preparing a second plate which is a metal plate and has punched holes in multiple rows;
(C) The first plate on both sides of the electrolyte layer so that the projection of the first plate is positioned on the electrolyte layer side and a gas flow path for gas supply is formed on the main surface side of the electrolyte layer. A step of arranging
(D) Closing the punched hole of the second plate with the plate surface of the first plate to form the closed punched hole as a cooling flow path through which the cooling medium passes. And a step of joining the first plate to the first plate. A method of manufacturing a fuel cell according to claim 6,
The step (a) of preparing the first plate includes:
A method of manufacturing a fuel cell, wherein when forming the plurality of protrusions, opposing slits are formed at predetermined positions on a flat metal plate, and a space between the slits is pressed with a convex mold.

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