JP2005243559A - Separator for fuel cell, parallel type unit cell using it, and parallel type fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separator for a fuel cell which is low in manufacturing cost and improved in performance required for a separator, and also provide the fuel cell using the same. <P>SOLUTION: The separators for the fuel cell arranged respectively on both sides of MEA 33 comprise a partition plate 1 made of a conductive metal sheet and a counter-base 17 made similarly of a conductive metal sheet overlapped each other. On the partition plate 1, a plurality of generation/current collection parts 2 which have a plurality of long holes 3 arranged in parallel, vertical walls 7 which are formed on both sides of the each long holes 3 and are bent toward the surface of the partition plate 1, and a bottom wall 10 formed between the adjoining long holes 3, are installed in parallel with intervals. On the counter-base plate 17, a plurality of housing parts 19 which house the vertical walls 7 of the generation/ current collection parts 2 and contact the tip part of the vertical walls 7 are installed in parallel with spacings, and a passage 30 which supplies fuel to the above MEA 33 is respectively formed in the space surrounded by the vertical walls 7 and the housing parts 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a separator used in a fuel cell, a unit cell using the separator, and a fuel cell.

  A fuel cell is a battery that directly converts chemical energy into electric energy, and is being put to practical use in various fields such as a power source or power source of a vehicle such as an electric vehicle or a generator for a house. . In particular, the polymer electrolyte fuel cell (PEFC) operates at a lower temperature than other fuel cell systems and has a high output density, so that it is expected to be applied as a power source for automobiles and portables.

  Such a polymer electrolyte fuel cell obtains a necessary voltage from a “unit cell” composed of MEA (Membrane Electrolyte Assembly) and separators disposed on both sides of the MEA. As many as possible are stacked to form a stack.

  The separator mainly has a role of forming a flow path for supplying fuel (hydrogen and air or oxygen (hereinafter simply referred to as air)) to the MEA, and a role of collecting generated electricity in contact with the MEA. have.

  Currently developed separators can be roughly divided into the following three types.

  1) Metal thin plate separator: A metal plate is bent into a concavo-convex shape by pressing or the like to form a fuel flow path and a current collector (see Patent Documents 1 and 2).

  2) Resin separator: A fuel channel and a current collecting part formed by cutting a plate material formed by solidifying graphite powder with a thermosetting resin binder or the like (see Patent Document 3).

  3) Carbon separator: A fuel separator and a current collector formed by cutting a plate made of a high-strength carbon material.

JP-A-10-302814 JP 2001-325969 A JP-A-8-162131

  However, each of these separators has the following problems.

  1) Problems of the thin metal plate separator: Since the corners of the convex portions forming the current collecting portion have an R shape, the current collecting efficiency is poor. The shape is complex and difficult to manufacture.

  2) Problems of resin separator: Manufacturing cost is high. Thinning is difficult. Low strength compared to metal. If the graphite content is increased in order to increase the electrical conductivity, the moldability is deteriorated.

  3) Problem of carbon separator: production cost is high. Thinning is difficult. Low strength compared to metal.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a fuel cell separator, a unit cell using the same, and a fuel cell, which solve the above-mentioned problems, have a low manufacturing cost, and improve the performance required of the separator. .

  In order to achieve the above object, the invention according to claim 1 is a fuel cell separator disposed on each side of an MEA, and includes a partition plate made of a conductive metal plate and a receiving plate made of the same conductive metal plate. In the partition plate, a plurality of elongated holes arranged in parallel, a vertical wall formed on both sides of each elongated hole and bent with respect to the surface of the partition plate, and the adjacent length A plurality of power generation / collection units having a bottom wall formed between the holes are arranged in parallel at intervals, and the receiving plate accommodates the vertical wall of each power generation / collection unit, and the vertical wall thereof. A plurality of accommodating portions that are in contact with the tip of the wall are arranged in parallel at intervals, and the fuel supplied to the MEA is placed in a space surrounded by the vertical walls and the accommodating portions of the power generation / collecting portions. Each channel is formed.

  According to a second aspect of the present invention, the vertical wall is bent at an angle of approximately 90 ° with respect to the surface of the partition plate.

  According to a third aspect of the present invention, the end positions in the longitudinal direction of the vertical walls are formed so as to be different every other or plural, and the adjacent fuel flow paths are formed by the difference in the end positions of the vertical walls. It is made to communicate through the gap formed.

  According to a fourth aspect of the present invention, the gap is formed alternately at both ends in the longitudinal direction of the fuel flow path.

  According to a fifth aspect of the present invention, the receiving plate includes a protruding portion formed continuously from each of the housing portions, and the communication plate is formed at a position corresponding to the protruding portion. And an isolation hole provided outside the position corresponding to the overhang portion, and the fuel supplied from the communication hole passes through a communication passage partitioned by the overhang portion of the receiving plate and the partition plate. The fuel flows through the fuel flow path and is supplied from the isolation hole, and flows out in the thickness direction without flowing into the fuel flow path.

  According to a sixth aspect of the present invention, the partition plate and the receiving plate are formed by press-molding a conductive metal plate having a thickness of 0.2 mm or less.

  According to a seventh aspect of the present invention, the separator according to any one of the first to sixth aspects is disposed on each side of the MEA such that the bottom wall of the partition plate is in contact with the MEA. It is a thing.

  According to an eighth aspect of the present invention, the separator according to the fifth aspect is disposed on each side of the MEA so that the bottom wall of the partition plate is in contact with the MEA, and the communication hole of one separator The separation holes of the other separator are aligned and arranged, and the separation holes of one separator and the communication holes of the other separator are aligned and arranged to form a parallel unit cell.

  The invention according to claim 9 is a parallel fuel cell in which a plurality of unit cells according to claim 8 are stacked.

  According to a tenth aspect of the present invention, the receiving plate constituting the separator has a protruding portion that protrudes with respect to the surface of the receiving plate, and when the unit cell is stacked in a plurality, the protruding portion of the receiving plate of the adjacent separator is formed. A coolant flow path is formed between the portions and between the convex portion and the overhang portion of the backing plate.

  According to an eleventh aspect of the present invention, the convex portion is formed so as to surround the accommodating portion.

  According to the present invention, an excellent effect is exhibited that the manufacturing cost is low and the performance required for the separator can be improved.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  The separator of this embodiment is a separator for a polymer electrolyte fuel cell, and is characterized in that two members (partition plate and receiving plate) made of a conductive metal plate are overlapped.

  The second feature of the separator of the present embodiment is that a plurality of elements necessary for constituting a unit cell or a fuel cell are arranged in parallel at intervals. That is, by using the separator of the present embodiment, it is possible to configure a parallel type unit cell or fuel cell that integrally includes a plurality of unit cells or fuel cells that are arranged at intervals.

  FIG. 1 is a front view of a member called a partition plate, and FIG. 2 is a front view of a member called a receiving plate.

  As shown in FIG. 1, the partition plate 100 is made of a press-formed product of a conductive metal plate (for example, stainless steel having a thickness of 0.2 mm or less), and has three components necessary for constituting a unit cell or a fuel cell. Are formed at intervals. Here, they are referred to as a first component 100a, a second component 100b, and a third component 100c, respectively, from the left side in the figure. These components 100a, 100b, 100c all have the same structure.

  As shown in FIG. 2, the receiving plate 101 is similarly made of a press-formed product of a conductive metal plate (for example, stainless steel having a thickness of 0.2 mm or less), and there are constituent elements necessary for configuring a unit cell or a fuel cell. Three are formed at intervals. Here, they are referred to as the first component 101a, the second component 101b, and the third component 101c, respectively, from the left side in the figure. These constituent elements 101a, 101b, and 101c all have the same structure.

  By overlapping and joining the partition plate 100 and the receiving plate 101, the first component 100a, the second component 100b, and the third component 100c of the partition plate 100 are respectively the first configuration of the receiving plate 101. In cooperation with the element 101a, the second component 101b, and the third component 101c, three elements that perform a necessary function as a separator are arranged side by side.

  First, the structure of the partition plate 100 will be described with reference to FIGS. In the following description, only the first component 100a will be described as a representative of the components 100a, 100b, and 100c.

  3 is an enlarged front view of the first component 100a, FIG. 4 is an enlarged view of a portion A in FIG. 3, and FIG. 5 is a sectional view taken along line VV in FIG. FIG. 4 shows a state in which the portion A in FIG. 3 is rotated by approximately 90 ° for the sake of clarity.

  As shown in the figure, the power generation / collection unit 2 is formed at substantially the center of the first component 100a of the partition plate 100. The power generation / collection unit 2 extends in a direction substantially orthogonal to the side edge 1a of the partition plate 100, and is spaced at a predetermined interval in a direction (vertical direction in FIG. 3) substantially orthogonal to the upper and lower edges 1b of the partition plate 100. A plurality of elongated holes 3 arranged in parallel. A circular hole 5 having a diameter larger than the width of the long hole 3 is formed at both ends in the longitudinal direction (left and right direction in FIG. 3) of each long hole 3, and one side of the circular hole 5 (FIG. 4). A notch 6 extending continuously a predetermined distance in the longitudinal direction of the long hole 3 is continuously formed in the lower left part of the middle left). The notches 6 are formed on different side portions at both ends of the single long hole 3. That is, in FIG. 3, a notch 6 is formed in the lower part at the left end of each slot 3 and in the upper part at the right end.

  As can be seen from FIGS. 4 and 5, the vertical walls 7 bent at an angle of approximately 90 ° with respect to the surface of the partition plate 100 are formed on both sides of each slot 3. As described above, since the notch 6 is formed on one side of the end portion of the elongated hole 3 (lower left portion in FIG. 4), the end position k1 of the vertical wall 7 located on both sides of the elongated hole 3 is formed. k2 is different every other line (see FIG. 4).

  A groove 9 (see FIGS. 4 and 5) is formed in a space defined by each elongated hole 3 and a vertical wall 7 positioned on both sides of the elongated hole 3. Further, a cross wall 11 having a substantially U-shaped cross section is formed by a bottom wall 10 positioned between two adjacent elongated holes 3 and 3 and two vertical walls 7 positioned on both sides of the bottom wall 10. That is, the power generation / collection unit 2 includes the grooves 9 and the crosspieces 11 that are alternately formed along a direction (vertical direction in FIG. 3) substantially orthogonal to the upper and lower edges 1 b of the partition plate 100.

  The groove 9 functions as a fuel flow path for bringing fuel (hydrogen or air) into contact with an electrode of an MEA (not shown), and can also be called a power generation unit. On the other hand, the crosspiece 11 functions as a fuel flow path at the inner portion thereof, and the bottom wall 10 functions as a current collector that collects electrons generated in contact with the MEA.

  Such grooves 9 and crosspieces 11 can be formed by pressing a conductive metal thin plate. For example, after punching the circular hole 5 and the notch 6 in a thin metal plate by piercing, a slit is formed along the center in the width direction of the elongated hole 3 to be formed, and the elongated hole 5 and the notch positioned above and below are formed. 6 is connected with a slit. Then, the part located in the both sides of a slit is bent, and the vertical wall 7 and the long hole 3 are formed. Lastly, re-striking is performed to make the corner R of the bottom wall 10 and the vertical wall 7 sharp (edge). By such a process, the groove 9 and the crosspiece 11 can be formed.

  In the present embodiment, the cross-sectional area of the groove 9 and the crosspiece 11 is constant over the entire longitudinal direction, and the cross-sectional area of the groove 9 and the cross-sectional area of the crosspiece 11 are equal to each other. It is formed. By doing so, the flow velocity of the fuel flowing in the groove 9 and the crosspiece 11 can be made almost constant at all positions. Here, if the height of the vertical wall 7 (depth of the groove 9) is h and the plate thickness of the partition plate 1 is t, the width w1 of the groove 9 is w1 = 2 (ht−0.1). Can be represented. In addition, the numerical value 0.1 in this formula is a coefficient which considered the material surplus of the bending R part. And the cross-sectional area (= w1 × h) of the groove 9 and the cross-sectional area (= (w2-2t) × (ht)) in the crosspiece 11 of the crosspiece 11 necessary to make the same. The width W2 is w2 = {h · w1 / (ht)} + 2t. Thus, the widths w1 and w2 of the groove 9 and the crosspiece 11 are determined based on the height h of the vertical wall 7, the plate thickness t of the partition plate 1, and the like.

  Now, as shown in FIG. 3, in the first component 100 a of the partition plate 100, a flat flange portion 12 is formed at a portion outside the power generation / collection unit 2. The flange portion 12 serves to prevent the fuel supplied to the power generation / current collection portion 2 (the groove 9 and the crosspiece 11) from leaking to the outside when a receiving plate 101 and a partition plate 100 described later are joined. Fulfill. First to fourth fuel supply / discharge holes 13a, 13b, 15a, 15b are formed in the flange portion 12, respectively. The first fuel supply / discharge hole 13a and the second fuel supply / discharge hole 13b, and the third fuel supply / discharge hole 15a and the fourth fuel supply / discharge hole 15b are respectively located with respect to the central portion of the first component 100a. To the target (so as to face diagonally across the power generation / collection unit 2). Further, the first fuel supply / discharge hole 13a and the third fuel supply / discharge hole 15a are arranged at the upper part of the power generation / collection unit 2, and the second fuel supply / discharge hole 13b and the fourth fuel supply / discharge hole 15b are It is arranged at the lower part of the power generation / collection unit 2. Furthermore, coolant supply / discharge holes 16 a and 16 b are formed in the flange portion 12. The coolant supply / discharge holes 16a and 16b are disposed so as to straddle the power generation / collection unit 2 vertically.

  The above is the structure of the first component 100a. In the partition plate 100 of this embodiment, three components similar to the first component 100a are arranged in parallel. As can be seen from FIG. 1, the flange portion 12 is shared by adjacent portions of the constituent elements 100a, 100b, and 100c. By doing so, the interval between the constituent elements 100a, 100b, 100c can be reduced, and the length of the partition plate 100 (the length in the left-right direction in FIG. 1) can be shortened.

  Next, the structure of the backing plate 101 will be described with reference to FIGS. In the following description, only the first component 101a will be described as a representative of the components 101a, 101b, and 101c.

  6 is an enlarged front view of the first component 101a of the backing plate 101, FIG. 7A is a sectional view taken along line VIIa-VIIa in FIG. 6, and FIG. 7B is a sectional view taken along line VIIb-VIIb in FIG. 7 (c) is a sectional view taken along line VIIc-VIIc in FIG. In FIG. 6, a line indicated by a two-dot chain line indicates a bending (bending) line of the receiving plate 101.

  As shown in the figure, the accommodating portion 19 for accommodating the power generation / current collecting portion 2 (vertical wall 7) of the first component 100a of the partition plate 100 at the substantially central portion of the first component 101a of the backing plate 101. Is formed. The accommodating part 19 has a substantially rectangular shape, and when it is overlapped with another separator, a convex part 20 for forming a coolant flow path is formed between the accommodating part 19 and outside the convex part 20. A flat flange portion 21 is formed. As can be seen from FIG. 7, the flange portion 21 and the accommodating portion 19 are located on substantially the same plane, and the convex portion 20 protrudes below the flange portion 21 and the accommodating portion 19. As shown in FIG. 6, the convex portion 20 is formed so as to surround the accommodating portion 19. That is, the accommodating part 19 is formed in the area | region inside the convex part 20, and the flange part 21 is each formed in the area | region outside. The height d of the accommodating portion 19 (the depth of the convex portion 20, see FIG. 7B) is obtained by subtracting the plate thickness t of the partition plate 1 from the height h (see FIG. 5) of the vertical wall 7 of the partition plate 1. It is formed approximately equal to the dimension (ht).

  The first component 101a of the receiving plate 101 includes first and second communication holes 22a and 22b and first and second isolation holes 23a and 23b. The communication holes 22a and 22b and the isolation holes 23a and 23b are formed in the first to fourth fuel supply / discharge holes 13a of the first component 100a of the partition plate 100 when the partition plate 100 and the receiving plate 101 are overlapped. , 13b, 15a, and 15b.

  The first component 101a of the receiving plate 101 has a projecting portion 25 that is continuous with a part of the housing portion 19 and is located on the same plane as the housing portion 19, and has first and second communication holes. 22 a and 22 b are formed in the overhang portion 25. Accordingly, the fuel (hydrogen or air) supplied from one of the first and second communication holes 22a and 22b flows to the accommodating portion 19 through the overhang portion 25 and passes through the other overhang portion 25 to the first. And it is discharged | emitted from the other of 2nd communicating hole 22a, 22b.

  On the other hand, the first and second isolation holes 23 a and 23 b are formed in the isolation part 26 surrounded by the convex part 20, although the first and second isolation holes 23 a and 23 b are located on substantially the same plane as the accommodating part 19. Therefore, the fuel (air or hydrogen) supplied from the first and second separation holes 23 a and 23 b flows out in the thickness direction of the receiving plate 101 without flowing into the accommodating portion 19.

  Cooling liquid supply / discharge holes 27 a and 27 b are formed in the convex portion 20. The coolant supply / discharge holes 27a, 27b are aligned with the coolant supply / discharge holes 16a, 16b of the first component 100a of the partition plate 100 when the partition plate 100 and the receiving plate 101 are overlapped. It is formed.

  The above is the structure of the first component 101a. The receiving plate 101 of the present embodiment is provided with three similar components to the first component 101a. As can be seen from FIG. 2, the convex portion 20 is shared by the adjacent portions of the constituent elements 101 a, 101 b, and 101 c, and the flange portion 21 includes the accommodating portions 19 and convex portions 20 of all the constituent elements 101 a, 101 b, and 101 c. It is formed in an annular shape so as to surround it. By doing so, the interval between the constituent elements 101a, 101b, 101c can be narrowed, and the length of the receiving plate 101 (the length in the left-right direction in FIG. 2) can be shortened.

  The partition plate 100 and the receiving plate 101 described above are preferably subjected to a surface treatment such as metal plating for the purpose of preventing generation of an oxide film, preventing corrosion, preventing elution of metal ions, and imparting water repellency. However, at present, the development of metal materials is proceeding at a rapid pace. Therefore, if a material having the above-described characteristics is developed, of course, the surface treatment is unnecessary.

  Next, a separator formed by superposing the partition plate 100 and the receiving plate 101 will be described with reference to FIGS. FIG. 8 is a front perspective view showing an overlapping portion of the first component 100a of the partition plate 100 and the first component 101a of the receiving plate 101, and FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. .

  As shown in the drawing, the partition plate 100 in a state in which the distal end portion (the end portion opposite to the bottom wall 10) of the vertical wall 7 of each component 100a, 100b, 100c of the partition plate 100 faces the receiving plate 101 side. And the receiving plate 101 are overlapped to form the separator 29. At this time, the power generation / collection unit 2 of each component 100a, 100b, 100c of the partition plate 100 is received in the storage unit 19 of each component 101a, 101b, 101c of the plate 101. As described above, since the depth d of the receiving portion 19 of the receiving plate 101 is equal to the dimension obtained by subtracting the plate thickness t from the height h of the vertical wall 7 of the partition plate 100, the distal end portion of the vertical wall 7 is the receiving portion. When abutting 19, the flange portion 12 of the partition plate 100 and the convex portion 20 of the receiving plate 101 abut. Therefore, by joining the flange part 12 and the convex part 20, the circumference | surroundings of the electric power generation and current collection part 2 (accommodating part 19) can be sealed over the whole area, and it can prevent that a fuel leaks outside. Further, as shown in FIG. 8, the outer end k <b> 1 of the vertical wall 7 of the partition plate 100 contacts the left and right side walls 19 a of the housing portion 19. As a result, a plurality of fuel flow paths 30 defined by the vertical walls 7 are formed in the accommodating portion 19. More specifically, the fuel flow path 30 includes a flow path 30a formed by the groove 9 of the partition plate 100 and a flow path 30b formed in the crosspiece 11, and these flow paths 30a and 30b are in the vertical direction. Are alternately formed.

  As shown in FIG. 4, the inner end k <b> 2 of the vertical wall 7 does not come into contact with the side wall 19 a of the housing part 19, so that a gap is formed between the side wall 19 a of the housing part 19 and the inner end k <b> 2. Adjacent fuel flow paths 30 communicate with each other through this gap. This gap is formed alternately at the left and right ends of each fuel flow path 30.

  Returning to FIGS. 8 and 9, when the partition plate 100 and the receiving plate 101 are overlapped, the first fuel supply / discharge hole 13 a of the partition plate 100, the first through-hole 22 a of the receiving plate 101, and the first of the partition plate 100. 2 Fuel supply / discharge hole 13 b and second communication hole 22 b of receiving plate 101, third fuel supply / discharge hole 15 a of partition plate 100 and first isolation hole 23 a of receiving plate 101, fourth fuel supply of partition plate 100 The discharge hole 15b and the second isolation hole 23b of the receiving plate 101 are aligned with each other. Further, in the space defined by the flange portion 12 of the partition plate 100 and the overhang portion 25 of the receiving plate 101, the first fuel supply / discharge hole 13a and the first series of through holes 22a and the accommodating portion 19 (power generation / collection) are provided. A communication passage 31 that communicates with the electric part 2) and a communication passage 32 that communicates the housing part 19 with the second fuel supply / discharge hole 13b and the second communication hole 22b are formed.

  In this way, by separating the partition plate 100 and the receiving plate 101, a separator provided with a plurality (three in this case) of the power generation / collection units 2 is configured. In this embodiment, the partition plate 100 and the receiving plate 101 are joined by an adhesive having conductivity. However, the present invention is not limited in this respect, and other means may be used.

  Here, the present applicant has found that it is preferable to make the rigidity of the partition plate 100 larger than the plate 101 by making the plate thickness of the partition plate 100 larger than the plate thickness of the plate 101. This is related to the fact that the receiving plate 101 has a more complicated shape than the partition plate 100, and molding distortion is likely to occur. In other words, by making the rigidity of the partition plate 100 larger than that of the receiving plate 101, when the partition plate 100 and the receiving plate 101 are overlapped and joined, the receiving plate 101 is easily adapted to the shape of the partition plate 100. It becomes possible to absorb the molding strain and properly overlap. In addition, there is also an advantage that the sealing performance of the fuel flow path 30 and the like is improved by the spring effect by leaving a little molding distortion of the receiving plate 101.

  Next, the structure of the parallel unit cell configured using the separator 29 described above will be described with reference to FIGS. 10 and 11. FIG. 10 is a development view of one unit cell (unit cell constituted by the first components 100a and 101a of the partition plate 100 and the receiving plate 101) among the parallel type unit cells, and FIG. It is sectional drawing along the XI line. FIG. 11 is not a development view, but shows a state where all of the partition plates 100-1 and 100-2, the receiving plates 101-1 and 101-2, and the MEA 33 in FIG. 10 are joined. Also in the following description, only the part comprised by the 1st components 100a and 101a of the partition plate 100 and the receiving plate 101 is demonstrated.

  Now, as shown in FIGS. 10 and 11, unit cells 37 are formed by disposing separators 29-1 and 29-2 on both sides of the MEA 33. At this time, each separator 29-1, 29-2 is arrange | positioned so that the bottom wall 10 of the partition plate 100 may contact the electrode of the side surface of MEA33.

  More specifically, in FIG. 10 and FIG. 11, the separator 29-1 positioned above the MEA 33 is arranged so that the receiving plate 101-1 is positioned upward and the partition plate 100-1 is positioned downward. It arrange | positions so that the vertical wall 7 of the board 100-1 may extend toward upper direction.

  On the other hand, the separator 29-2 located on the lower side of the MEA 33 is disposed in a state where the upper separator 29-1 is reversed in the left-right direction in FIG. That is, the lower separator 29-2 is arranged such that the receiving plate 101-2 is positioned downward and the partition plate 100-2 is positioned upward, that is, the vertical wall 7 of the partition plate 100-2 is directed downward. It is arranged to extend.

  Thus, the two separators 29-1, 29-2 are arranged so that the partition plates 100-1, 100-2 face each other across the MEA 33, so that the partition plates of both the separators 29-1, 29-2. The bottom walls 10 of 100-1 and 100-2 are in contact with the side surfaces of the MEA 33, respectively. As a result, as shown in FIG. 11, the openings of the grooves 9 (fuel flow paths 30 a) of the partition plates 100-1 and 100-2 are covered with the side surfaces of the MEA 33.

  When the two separators 29-1 and 29-2 are arranged on both sides of the MEA 33, as shown in FIG. 10, the first series of through holes 22a and the first fuel supply / discharge of one separator 29-1 (upper side in the figure). The hole 13a (the hole communicated with the power generation / collection unit 2 by the communication passage 31), the fourth fuel supply / discharge hole 15b and the second separation hole 23b (convex) of the other (lower side in the figure) separator 29-2. The holes separated from the power generation / collection unit 2 by the unit 20 are aligned. Similarly, the second communication hole 22b and the second fuel supply / discharge hole 13b of one separator 29-1 are aligned with the third fuel supply / discharge hole 15a and the first isolation hole 23a of the other separator 29-2. The first separation hole 23a and the third fuel supply / discharge hole 15a of one separator 29-1 are aligned with the second fuel supply / discharge hole 13b and the second communication hole 22b of the other separator 29-2. The second separation hole 23b and the fourth fuel supply / discharge hole 15b of the separator 29-1 are aligned with the first fuel supply / discharge hole 13a and the first series of through holes 22a of the other separator 29-2.

  In this parallel unit cell 37, both fuels (hydrogen and air) are supplied from the first through hole 22a and the first isolation hole 23a of the receiving plate 101-1 of one separator 29-1.

  One fuel (in this case, hydrogen) supplied from the first series of through holes 22a flows through the communication passage 31 to the power generation / collection unit 2 side of the separator 29-1, and passes through each fuel passage 30. Flowing. Hydrogen flows in the longitudinal direction of the fuel flow path 30 and flows into the adjacent fuel flow path 30 from the gap described above at the end thereof, and flows in the reverse direction in the fuel flow path 30 (see FIG. 4). That is, hydrogen flows by alternately turning back the fuel flow path 30 a formed by the groove 9 and the fuel flow path 30 b formed by the crosspiece 11. At this time, the direction of hydrogen flowing in the fuel flow path 30a formed by the groove 9 is the same in all the flow paths 30a, and the direction of hydrogen flowing in the fuel flow path 30b formed by the crosspiece 11 is also in all the flow paths 30b. It will be the same.

  Hydrogen flowing in the fuel flow path 30 a formed by the groove 9 contacts one side (negative electrode) of the MEA 33 and contributes to power generation, and hydrogen flowing in the crosspiece 11 does not contact the MEA 33. This is because this region is a region for collecting generated electricity by the crosspiece 11 (bottom wall 10). The fuel that has flowed through the fuel flow path 30 flows into the second fuel supply / discharge hole 13b of the partition plate 100-1 through the communication path 32, the hole 35 formed in the MEA 33, and the partition of the other separator 29-2. It is discharged in the thickness direction through the third fuel supply / discharge hole 15a of the plate 100-2 and the first isolation hole 23a of the receiving plate 101-2.

  In addition, a part of the hydrogen supplied from the first through hole 22a of the receiving plate 101-1 of the separator 29-1 is a hole formed in the first fuel supply / discharge hole 13a and the MEA 33 of the partition plate 100-1. Flows through the other separator 29-2. As described above, the first fuel supply / discharge hole 13a of the separator 29-1 and the fourth fuel supply / discharge hole 15b and the second isolation hole 23b of the other separator 29-2 (the power generation / collection unit 2 by the convex portion 20). Therefore, the hydrogen flowing into the separator 29-2 does not flow into the power generation / collection unit 2 of the separator 29-2, but the fourth fuel supply / discharge hole 15b. And it flows out in the thickness direction from the second isolation hole 23b.

  On the other hand, the fuel (in this case, air) supplied from the second separation hole 23a of the receiving plate 101-1 of the upper separator 29-1 does not flow to the power generation / collection unit 2 side of the separator 29-1, It flows through the third fuel supply / discharge hole 15a of the partition plate 100-1 and the hole 35 formed in the MEA 33 to the second fuel supply / discharge hole 13b of the partition plate 100-2 of the lower separator 29-2. . Part of the air that has flowed into the second fuel supply / discharge hole 13b flows through the communication passage 32 to the power generation / collection unit 2 (fuel flow path 30), and the other side of the MEA 33 ( Contact the positive electrode) to contribute to power generation. After that, it is discharged in the thickness direction from the first through hole 22a of the receiving plate 101-2 through the communication passage 31. Further, part of the air that has flowed into the second fuel supply / discharge hole 13b of the partition plate 100-2 flows out in the thickness direction through the second communication hole 22b of the receiving plate 101-2.

  The above is the unit structure of the unit cell, and by arranging the separator 29 composed of the partition plate 100 and the receiving plate 101 of this embodiment on both sides of the MEA 33, three unit cells having the same structure are arranged side by side. .

  A parallel fuel cell constructed by stacking a plurality of the parallel unit cells will be described with reference to FIGS. Also in the following description, only the part comprised by the 1st components 100a and 101a of the partition plate 100 and the receiving plate 101 is demonstrated.

  FIG. 12 is a partial side cross-sectional view of a parallel fuel cell, and FIG. 13 is an enlarged view of part B of FIG.

  In this fuel cell 36, a plurality of unit cells 37 similar to those shown in FIG. 11 are stacked, and a separator 29 ′ for forming a coolant flow path and a pressing plate 39 are disposed on the upper and lower surfaces of the stacked body. The whole is integrally fixed by bolting or the like.

  In this fuel cell 36, the fuel (here, hydrogen) supplied from the first through hole 22 a of the receiving plate 101 of the separator 29 on the upper side of the unit cell 37 stacked on the uppermost portion is a communication path of the separator 29. It flows to the power generation / collection unit 2 through 31 and contributes to power generation, and is discharged from the second fuel supply / discharge hole 13b of the partition plate 100 in the thickness direction. Further, a part of the hydrogen supplied from the first series of through holes 22 a of the receiving plate 101 is supplied to the holes 35 of the MEA 33 and the third fuel supply / discharge holes 15 b of the partition plate 100 of the lower separator 29 and the receiving plate 101. It flows through the second isolation hole 23b to the first through hole 22a of the receiving plate 101 of the separator 29 on the upper side of the adjacent unit cell 37. Then, it flows to the power generation / collection unit 2 through the communication passage 31 of the separator 29. That is, hydrogen is supplied only to the power generation / collection unit 2 of the upper separators 29 of all the unit cells 37 (the separators 29 disposed on the negative electrode side of the MEA 33).

  On the other hand, the air supplied from the first isolation holes 23a of the receiving plate 101 of the separator 29 on the upper side of the unit cell 37 stacked on the top is separated from the separators 29 on the lower side of all the unit cells 33 (on the positive side of the MEA 33). It is supplied only to the power generation / collection unit 2 of the separator 29) arranged.

  As a result, hydrogen is supplied to the negative electrodes of the MEAs 33 of all the unit cells 37 and air is supplied to the positive electrodes, and power generation is performed. The electricity generated in each unit cell 37 is collected by the current collector (crosspiece 11) of the separator 29 and taken out to the outside. Further, the electrical connection (connection) between the adjacent unit cells 37 is such that the receiving plates 101 of the separators 29 are in contact with each other on the back surface (the surface opposite to the side facing the partition plate 100) in the adjacent unit cells 37. Is ensured by More specifically, as shown in FIG. 13, the separation portion 26 of one receiving plate 101 and the projecting portion 25 of the other receiving plate 101 come into contact with each other.

  Further, in the fuel cell 36, the coolant flow path 40 is formed between the two separators 29 (29 ′) that are overlapped and joined together. The coolant channel 40 is formed between the convex portions 20 of the receiving plate 101 of the separator 29 (29 ′) and between the convex portion 20 and the overhang portion 25. The coolant supplied from one of the coolant supply / discharge holes 27a, 16a and the coolant supply / discharge holes 27b, 16b (see FIG. 8) of each separator 29 extends along the coolant channel 40 (convex portion 20). The separator 29 flows around the power generation / collection unit 2 and is discharged from the other of the coolant supply / discharge holes 27b, 16b and the coolant supply / discharge holes 27a, 16a.

  As shown in FIG. 13, a spacer 41 is interposed between the end edge (flange portion 12) of the partition plate 100 and the end edge (flange portion 21) of the receiving plate 101 in each separator 29. By providing the spacer 41, when the unit cells 37 are stacked and tightened, the separator 29 (partition plate 100 and receiving plate 101) and the MEA 33 can be tightened with uniform surface pressure, and stress concentration can be prevented. As described above, since the sealing of the fuel and the coolant is achieved by joining the partition plate 100, the receiving plate 101, and the receiving plate 101, it is not necessary for the spacer 41 to have a sealing function. Therefore, the spacer 41 can be manufactured at a relatively low cost.

  The above is the single structure of the fuel cell, and by stacking unit cells using the separator 29 composed of the partition plate 100 and the receiving plate 101 of this embodiment, three fuel cells having the same structure are arranged side by side. The It is possible to take out the power independently from each fuel cell or to take out the power of all the fuel cells collectively.

  For example, when the fuel cell is mounted on a vehicle or the like, the fuel flow path 30 of each separator 29 extends in the horizontal direction (lateral direction), and the hole for supplying fuel is positioned at the top. Therefore, the supplied fuel flows in the fuel flow path 30 of the separator 29 of each unit cell 37 in the lateral direction and from the upper stage to the lower stage.

  According to the separator of the present embodiment as described above, the unit cell using the separator, and the fuel cell, the following effects can be obtained.

  1) Since the separator 29 is divided into the partition plate 100 and the receiving plate 101, the shape of each member 100, 101 is simple and easy to manufacture. Moreover, the manufacturing cost is low.

  2) Since the structure of the partition plate 100 is simple and manufacture is easy, the corner | angular part R of the vertical wall 7 and the bottom wall 10 (current collection part) can be sharpened. Therefore, current collection efficiency is good.

  3) Since it is a press-molded product of a thin metal plate, it can be made thinner than resin and carbon separators. For example, even the thinnest resin separator currently developed is about 2 mm, but in the separator of this embodiment, it can be easily made 1 mm or less.

  4) Since the coolant flows annularly around the power generation / collection unit 2, heat generated by power generation can be effectively absorbed, and the temperature rise suppression effect is high.

  5) Since the coolant channel 40 is formed by stacking the separators 29, it is not necessary to separately provide a member for forming the coolant channel 40, reducing the number of parts, reducing the manufacturing cost, and reducing the thickness of the separator. Can be planned.

  Furthermore, in this embodiment, a plurality of unit cells or fuel cells can be integrally configured by arranging a plurality of power generation / collection units 2 on the partition plate 100 and a plurality of accommodating units 19 on the receiving plate 101, respectively. Since it was made possible, the following effects can also be obtained.

  1) By arranging a plurality of fuel cells in parallel, the stack height (thickness) necessary for obtaining the same power can be reduced. Therefore, it can be mounted in a place where there is little space, such as under the vehicle body floor, and the degree of freedom of the mounting position is increased.

  2) When the same electric power is obtained, the size of each part of the partition plate 100 and the receiving plate 101 (the power generation / current collection unit 2, the storage unit 19, etc.) can be reduced as compared with a single fuel cell. Therefore, each part of the mold can be reduced, and the mold manufacturing cost can be suppressed.

  3) By reducing the stack height of the fuel cell, the cooling water flow path in each fuel cell is shortened, and the cooling water discharge performance is improved.

  4) By arranging a plurality of fuel cells in parallel, even when a certain fuel cell becomes unusable, power supply can be secured by the remaining fuel cells.

  5) Since cooling water can be convected between adjacent fuel cells, the cooling efficiency of heat generated during power generation is high.

  6) Since the fuel flow path extends in the horizontal direction (lateral direction) and the fuel flows through each fuel flow path from the upper stage to the lower stage, the discharge performance of the reaction water generated on the air electrode side is good. In other words, when the fuel flow path extends in the vertical direction, there is a fuel flow path in which water must move from the lower side to the upper side against gravity, so that the discharge performance is deteriorated. The same problem occurs when fuel is allowed to flow from the lower stage to the upper stage. Considering this, it is preferable to design at least air (or oxygen) to flow from the upper stage to the lower stage in the fuel flow path.

  The present invention is not limited to the embodiment described above.

  For example, the number of the power generation / collection units 2 and the accommodating units 19 formed on the partition plate 100 and the receiving plate 101 is not limited to three, and may be two or less or four or more.

  In each unit cell and fuel cell, the number and length of the fuel flow paths 30 are not limited to those shown in the figure.

  Furthermore, in the above-described embodiment, the end positions k1 and k2 of the vertical wall 7 forming the fuel flow path 30 are alternately different, and the fuel is described as alternately turning back the fuel flow paths 30. However, the position of the end portion of the vertical wall 7 may be varied every plurality. For example, the fuel may flow in a plurality of adjacent fuel flow paths in the same direction, and then turn back at the end portion to flow into one or a plurality of fuel flow paths.

  In the above-described embodiment, the flow path cross-sectional area of the fuel flow path 30 is the same at all positions, but the present invention is not limited in this respect. For example, the cross-sectional area of each fuel flow path 30 may be different in the longitudinal direction, or the cross-sectional area of the fuel flow path 30a formed by the groove 9 and the fuel flow path 30b formed by the crosspiece 11 The cross-sectional area may be different.

It is a front view of the partition plate which is one of the structural members of the separator which concerns on one Embodiment of this invention. It is a front view of the receiving plate which is one of the structural members of the separator which concerns on one Embodiment of this invention. It is an enlarged front view of the 1st component of the partition plate of FIG. It is the A section enlarged view of FIG. It is the VV sectional view taken on the line of FIG. It is an enlarged front view of the 1st component of the receiving plate of FIG. (A) is the VIIa-VIIa sectional view taken on the line of FIG. 6, (b) is the VIIb-VIIb sectional view of FIG. 6, (c) is the VIIc-VIIc sectional view of FIG. It is a front perspective view which shows the state which piled up the partition plate and the receiving plate. It is the IX-IX sectional view taken on the line of FIG. It is an expanded view which shows one unit cell among parallel type | mold unit cells. It is sectional drawing along the XI-XI line of FIG. 10, and has shown the state which joined the separator and MEA. It is a partial side sectional view of a parallel type fuel cell configured by stacking parallel type unit cells. It is the B section enlarged view of FIG.

Explanation of symbols

2 Power generation / collection section 3 Long hole 7 Vertical wall 9 Groove 10 Bottom wall 11 Cross 13a First fuel supply / discharge hole 13b Second fuel supply / discharge hole 15a Third fuel supply / discharge hole 15b Fourth fuel supply / discharge Hole 19 Accommodating part 20 Protruding part 22a First communication hole 22b Second communication hole 23a First isolation hole 23b Second isolation hole 25 Overhang part 29 Separator 30 Fuel flow path 31 Communication path 32 Communication path 33 MEA
36 Fuel cell 37 Unit cell 40 Coolant flow path 100 Partition plate 101 Back plate

Claims (11)

Fuel cell separators disposed on both sides of the MEA,
Constructed by overlapping a partition plate made of a conductive metal plate and a receiving plate made of the same conductive metal plate,
The partition plate includes a plurality of elongated holes arranged in parallel, a vertical wall formed on both sides of each elongated hole and bent with respect to the surface of the partition plate, and a bottom wall formed between the adjacent elongated holes. A plurality of power generation / collection units equipped with
The receiving plate accommodates the vertical wall of each of the power generation / collection units, and a plurality of accommodating units that come into contact with the front end of the vertical wall are arranged in parallel at intervals.
A fuel cell separator, wherein a flow path for fuel to be supplied to the MEA is formed in a space surrounded by the vertical wall of the power generation / collection unit and the storage unit.   2. The fuel cell separator according to claim 1, wherein the vertical wall is bent at an angle of approximately 90 [deg.] With respect to the surface of the partition plate. The longitudinal position of the vertical wall is formed so that every other or every other position is different,
The fuel cell separator according to claim 1 or 2, wherein adjacent fuel flow paths communicate with each other through a gap formed by a difference in end position of the vertical wall.   The fuel cell separator according to claim 3, wherein the gap is formed alternately at both ends in the longitudinal direction of the fuel flow path. The receiving plate includes an overhang portion formed continuously with each of the accommodating portions, and the partition plate corresponds to the overhang portion formed in a position corresponding to the overhang portion. An isolation hole provided outside the position to be
The fuel supplied from the communication hole flows to the fuel flow path through the communication passage defined by the protruding portion of the receiving plate and the partition plate, and the fuel supplied from the isolation hole is the fuel. The fuel cell separator according to any one of claims 1 to 4, which flows out in the thickness direction without flowing into the flow path.   The fuel cell separator according to any one of claims 1 to 5, wherein the partition plate and the receiving plate are formed by press-molding a conductive metal plate having a thickness of 0.2 mm or less.   A parallel unit cell, wherein the separator according to any one of claims 1 to 6 is disposed on both sides of the MEA so that the bottom wall of the partition plate is in contact with the MEA.   The separator according to claim 5 is disposed on each side of the MEA so that the bottom wall of the partition plate is in contact with the MEA, and the communication hole of one separator and the isolation hole of the other separator A parallel type unit cell in which the separation holes of one separator and the communication holes of the other separator are aligned and arranged.   A parallel fuel cell comprising a plurality of unit cells according to claim 8 stacked. The receiving plate that constitutes the separator has a protruding portion that protrudes with respect to the surface of the receiving plate,
The cooling liquid flow path is formed between the convex portions of the receiving plates of the separators adjacent to each other and between the convex portions and the projecting portions of the receiving plates when the unit cells are stacked in plurality. Parallel type fuel cell. The parallel fuel cell according to claim 10, wherein the convex portion is formed so as to surround the accommodating portion.

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