WO2019239605A1 - Gas supply diffusion layer for fuel cell, separator for fuel cell, and fuel cell stack - Google Patents

Gas supply diffusion layer for fuel cell, separator for fuel cell, and fuel cell stack Download PDF

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Publication number
WO2019239605A1
WO2019239605A1 PCT/JP2018/023031 JP2018023031W WO2019239605A1 WO 2019239605 A1 WO2019239605 A1 WO 2019239605A1 JP 2018023031 W JP2018023031 W JP 2018023031W WO 2019239605 A1 WO2019239605 A1 WO 2019239605A1
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WIPO (PCT)
Prior art keywords
fuel cell
diffusion layer
gas supply
supply diffusion
isolated
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PCT/JP2018/023031
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French (fr)
Japanese (ja)
Inventor
浩 谷内
渡辺　政廣
Original Assignee
株式会社エノモト
国立大学法人山梨大学
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Application filed by 株式会社エノモト, 国立大学法人山梨大学 filed Critical 株式会社エノモト
Priority to PCT/JP2018/023031 priority Critical patent/WO2019239605A1/en
Priority to JP2020525079A priority patent/JP7047090B2/en
Publication of WO2019239605A1 publication Critical patent/WO2019239605A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/023—Porous and characterised by the material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to a gas supply diffusion layer for fuel cells, a separator for fuel cells, and a fuel cell stack.
  • FIG. 20 is a front view schematically showing a conventional fuel cell stack 920.
  • 21 and 22 are plan views of a type CA separator 921 in a conventional fuel cell stack 920.
  • FIG. 21 is a plan view of the fuel cell gas supply diffusion layer (cathode gas supply diffusion layer) 942 side
  • FIG. 22 is a fuel cell gas supply diffusion layer (anode gas supply diffusion layer) 941 side.
  • FIG. 23 is a sectional view taken along line AA in FIG.
  • a conventional fuel cell stack 920 includes a plurality of separators having a structure in which a fuel cell gas supply diffusion layer is provided on at least one surface of a metal plate 30 as a porous body layer.
  • a type CA separator 921, a type A separator 922, a type C separator 923, and a type AW separator 924) are stacked.
  • “A” in the type CA separator 921, the type A separator 922, and the type AW separator 924 represents the gas supply diffusion layer (anode gas supply diffusion layer) 941 for the fuel cell, and the type CA separator 921 and type C.
  • the fuel cell gas supply diffusion layers 941 and 942 formed of the porous body layer are formed on the separator itself, so that the fuel cell gas is supplied to the fuel cell gas supply diffusion layer. Can diffuse uniformly over the entire surface. As a result, the fuel cell gas can be supplied uniformly over the entire surface of the membrane electrode assembly (MEA) 81, and the power generation efficiency of the fuel cell can be increased as compared with the conventional case.
  • MEA membrane electrode assembly
  • an object of the present invention is to provide a fuel cell gas supply diffusion layer, a fuel cell separator, and a fuel cell stack, which can increase the power generation efficiency of the fuel cell as compared with the prior art.
  • a fuel cell gas supply diffusion layer is a fuel cell gas supply diffusion layer through which fuel cell gas flows from upstream to downstream during use, and transmits and diffuses the fuel cell gas.
  • a porous body layer having conductivity the porous body layer comprising a gas diffusion portion made of a porous body, and a plurality of isolated holes arranged dispersed on one surface of the porous body layer
  • Each of the isolated holes is formed in the porous body layer so as to be isolated from each other, and the periphery excluding the opening is surrounded by the gas diffusion portion and includes a recess having a bottom of the porous body.
  • a fuel cell separator is a fuel cell separator comprising a gas shielding plate and a fuel cell gas supply diffusion layer disposed on at least one surface of the gas shielding plate,
  • the fuel cell gas supply diffusion layer is a fuel cell gas supply diffusion layer according to the present invention, and the fuel cell gas supply diffusion layer has the plurality of isolated holes positioned on the gas shielding plate side. It arrange
  • a fuel cell stack according to an aspect of the present invention is a fuel cell stack formed by laminating a fuel cell separator and a membrane electrode assembly, and the fuel cell separator is the fuel cell separator of the present invention.
  • the fuel cell separator and the membrane electrode assembly are in a positional relationship in which the membrane electrode assembly is positioned on the surface of the fuel cell gas supply diffusion layer where the plurality of isolated holes are not formed. Are stacked.
  • the power generation efficiency of the fuel cell can be increased as compared with the conventional case, and further, the drainage performance is superior as compared with the conventional case.
  • FIG. 5 is a cross-sectional view of FIG. 4. It is a figure shown in order to demonstrate the flow of the gas for fuel cells. 4 is a cross-sectional view of a fuel cell separator (fuel cell separators 21, 22, 24, 25) other than the fuel cell separator 23.
  • FIG. 7 is a plan view of a fuel cell gas supply diffusion layer 42a according to Modification 1.
  • FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42b according to Modification 2.
  • FIG. 14 is a plan view of a fuel cell gas supply diffusion layer 42c according to Modification 3.
  • FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42d according to Modification 4.
  • FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42e according to Modification 5.
  • 14 is a plan view of a fuel cell gas supply diffusion layer 42f according to Modification 6.
  • FIG. 14 is a plan view of a fuel cell gas supply diffusion layer 42g according to Modification 7.
  • FIG. 14 is a plan view of a fuel cell gas supply diffusion layer 42h according to Modification 8.
  • FIG. FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42i according to Modification 9.
  • 14 is a plan view of a fuel cell gas supply diffusion layer 42j according to Modification 10.
  • FIG. 9 is a plan view of a fuel cell separator 921 of type CA in a conventional fuel cell stack 920.
  • FIG. 9 is a plan view of a fuel cell separator 921 of type CA in a conventional fuel cell stack 920.
  • FIG. 22 is a cross-sectional view taken along line AA in FIG. 21.
  • FIG. 1 is a front view schematically showing a fuel cell stack 20 according to an embodiment.
  • FIG. 2 is a side view schematically showing the fuel cell stack 20 according to the embodiment.
  • the fuel cell stack 20 is a polymer electrolyte fuel cell (PEFC).
  • the fuel cell stack 20 has a plurality of single cells.
  • a single cell of a fuel cell is conceptually composed of an electrolyte membrane (polymer membrane) (which may include a catalyst layer), an element constituting the cathode side sandwiching the membrane, and an element constituting the anode side.
  • each cell of the fuel cell stack 20 has an element constituting the cathode side and an element constituting the anode side with a membrane electrode assembly 81 described later interposed therebetween.
  • a plurality of cells are stacked with a separator in between to constitute a fuel cell stack 20.
  • the separator for a fuel cell according to the embodiment of the present invention includes a metal plate 30 that separates cells and is configured with various variations.
  • the fuel cell separator 21 has a cathode gas supply diffusion layer C formed on one surface of a metal plate 30 as a gas shielding plate, and an anode gas supply diffusion layer A formed on the other surface (type CA separator). ). Therefore, the cathode gas supply diffusion layer C and the anode gas supply diffusion layer A of the type CA separator according to the embodiment of the present invention are incorporated in different cells. Details of the type CA separator will be described later.
  • the fuel cell separator 22 has an anode gas supply diffusion layer A formed on one surface of a metal plate 30 (type A separator).
  • a cathode gas supply diffusion layer C is formed on one surface of a metal plate 30 (type C separator).
  • the cathode gas supply diffusion layer C is formed on one surface of the metal plate 30, and the cooling water supply diffusion layer W is formed on the other surface (type CW separator).
  • Each cell is arranged so that the cathode side and the anode side alternate.
  • the cathode gas supply diffusion layer C and the anode gas supply diffusion layer A are provided to face each other with a membrane electrode assembly (MEA) 81 interposed therebetween.
  • MEA membrane electrode assembly
  • a cooling water supply diffusion layer W that supplies cooling water every time two single cells are arranged is provided.
  • the cooling water supply diffusion layer W may be provided every other single cell, or every three or more.
  • Fuel cell separators 21 to 24 are combined and laminated so that the cooling water supply diffusion layer W faces the metal plate 30 (preferably the metal plate 30 in the type A or type C separator).
  • the anode gas supply diffusion layer A is formed on one surface of the metal plate 30, and the cooling water supply diffusion is formed on the other surface. It may be provided with a layer W formed (type AW separator). Further, a separator (type W separator) in which the cooling water supply diffusion layer W is formed on one surface of the metal plate 30 may be provided. Further, a separator in which the cooling water supply diffusion layer W is formed on both surfaces of the metal plate 30 may be provided. Details of the configuration of each fuel cell separator will be described later.
  • Current collector plates 27A and 27B are disposed at both ends of the stacked cells. Further, end plates 75 and 76 are disposed outside the current collecting plates 27A and 27B via insulating sheets 28A and 28B. The fuel cell separators 21 to 24 are pressed from both sides by end plates 75 and 76. For the fuel cell separators located at both ends of the fuel cell stack 20 and in contact with the current collector plates 27A and 27B, the metal plate 30 (corrosion resistant layer) is preferably directed outward.
  • the fuel cell separators 21 to 24, the membrane electrode assembly 81, the current collector plates 27A and 27B, the insulating sheets 28A and 28B, and the end plates 75 and 76 are shown for easy understanding. Although depicted spaced apart, they are intimately joined to each other in the order shown.
  • the method for joining is not particularly limited.
  • the members may be joined only by pressing the members from both sides with the end plates 75, 76, or the respective members may be joined from both sides by the end plates 75, 76 after bonding the appropriate positions of the members with an adhesive. It may be joined by pressing, or may be joined by other methods.
  • Each of the fuel cell separators 21 to 24, the membrane electrode assembly 81, the current collecting plates 27A and 27B, the insulating sheets 28A and 28B, and the like have a thickness of about 100 ⁇ m to about 10 mm, for example. Each figure in each embodiment of the present specification is drawn with exaggerated thickness.
  • An anode gas supply port 71A, a cathode gas discharge port 72B, and a cooling water discharge port 73B are provided at one end of the anode side end plate 75, respectively.
  • an anode gas discharge port 71B, a cathode gas supply port 72A, and a cooling water supply port 73A are the ends of the cathode side end plate 76 (the side opposite to the one end of the end plate 75)). (Shown collectively in broken lines).
  • Corresponding fluid supply pipes and discharge pipes are connected to the supply ports and the discharge ports, respectively.
  • Each of the fuel cell separators 21 to 24 has an anode gas inlet 61A communicating with the anode gas supply port 71A, a cathode gas (and product water) outlet 62B communicating with the cathode gas outlet 72B, and cooling water.
  • a cooling water outlet 63B communicating with the discharge port 73B is provided.
  • Each of the fuel cell separators 21 to 24 has an anode gas outlet 61B communicating with the anode gas discharge port 71B, a cathode gas inlet 62A communicating with the cathode gas supply port 72A, and a cooling water supply port 73A.
  • a cooling water inlet 63 ⁇ / b> A communicating with the cooling water is provided.
  • the cathode gas, the anode gas, and the cooling water are supplied through the anode gas supply port 71A, the cathode gas supply port 72A, and the cooling water supply port 73A.
  • the cathode gas supply port 72A In the embodiment, a case where hydrogen gas is used as the anode gas and air is used as the cathode gas is illustrated.
  • FIG. 3 is a view for explaining a membrane electrode assembly (MEA) 81.
  • 3A is a plan view of the membrane electrode assembly 81
  • FIG. 3B is a front view of the membrane electrode assembly 81
  • FIG. 3C is a side view of the membrane electrode assembly.
  • the membrane electrode assembly 81 is arranged on an electrolyte membrane (PEM) 82, catalyst layers (CL) 85 arranged on both surfaces of the electrolyte membrane 82, and on the outer surface of each catalyst layer 85.
  • the microporous layer (MPL) 83 is provided.
  • a structure composed of the electrolyte membrane 82 and the catalyst layers 85 disposed on both sides thereof is referred to as a catalyst coated electrolyte membrane (Catalyst Coated Membrame: CCM).
  • the microporous layer 83 has pores (pores) with a diameter smaller than that of the porous body layer 40.
  • the microporous layer 83 can be omitted.
  • FIG. 4 is a plan view of the type C fuel cell separator 23 as viewed from the metal plate 30 side. However, in FIG. 4, the illustration of the metal plate 30 is omitted for easy understanding of the flow path pattern of the fuel cell separator 23.
  • FIG. 5 is a cross-sectional view of FIG. 5A is a cross-sectional view along A1-A4 in FIG. 4 (however, the A2-A3 portion is omitted), and FIG. 5B is a cross-sectional view along A2-A3 in FIG. In FIG.
  • FIG. 6 is a view for explaining the flow of the fuel cell gas.
  • 6A is an enlarged plan view of a portion B in FIG. 4, and
  • FIG. 6B is a cross-sectional view taken along the line CC in FIG. 6A.
  • FIGS. 4 to 6 there are cases where the reference numerals (551) to (553) in parentheses are shown after the reference numeral 55 indicating an isolated hole.
  • the reference numerals in parentheses indicate the relative positional relationship of each isolated hole. It is shown for convenience of explanation, and does not indicate an isolated hole at a specific position.
  • the flow of the cathode gas is indicated by an arrow.
  • the thick arrow indicates the overall flow of the cathode gas from the inflow side to the outflow side.
  • the thin arrow indicates that the cathode gas flows from the isolated hole 55 into the gas diffusion portion 43.
  • the flow of the pushed cathode gas (downflow gas flow) is shown.
  • the fuel cell separator 23 has a structure in which a fuel cell gas supply diffusion layer 42 is formed on one surface of the metal plate 30.
  • the metal plate 30 is hatched to indicate a cross section.
  • the metal plate 30 is preferably a metal composed of one or more of Inconel, nickel, gold, silver and platinum, or a metal plating or clad material on an austenitic stainless steel plate. Corrosion resistance can be improved by using these metals.
  • a cathode gas inlet 62A, a cooling water inlet 63A, and an anode are arranged at one end (the lower part in FIG. 4) of the metal plate 30 in the order of right, center, and left in FIG.
  • a gas outlet 61B is provided.
  • a cathode gas outlet 62B, a cooling water outlet 63B, and an anode gas inlet 61A are provided at the other end (upper part of FIG. 4) in the order of left, center, and right in FIG.
  • Each of the inlets 61A, 62A, 63A, each of the outlets 61B, 62B, 63B, and the periphery of the formation region of the fuel cell gas supply diffusion layer 42 is surrounded by an electron conductive or non-electron conductive dense frame 32. being surrounded.
  • the dense frame 32 prevents leakage of anode gas, cathode gas and cooling water.
  • the respective inlets 61 ⁇ / b> A, 62 ⁇ / b> A, 63 ⁇ / b> A, the outlets 61 ⁇ / b> B, 62 ⁇ / b> B, 63 ⁇ / b> B, and the fuel cell gas supply diffusion layer 42 are formed.
  • a groove 33A is formed (not shown in FIG. 4).
  • a gasket (a sealing material such as a packing and an O-ring) 33 is disposed in the groove 33A.
  • the entire surface of the metal plate 30 has a corrosion-resistant layer having electronic conductivity (Not shown in FIG. 5).
  • Corrosion-resistant layers may be formed on the inner peripheral surfaces of the inflow ports 61A, 62A, and 63A and the outflow ports 61B, 62B, and 63B.
  • Corrosion-resistant layers may be formed on the side surfaces and end surfaces of the metal plate 30.
  • the corrosion-resistant layer is preferably a dense layer having the same composition as the dense frame 32 and has an action of suppressing corrosion of the metal plate 30.
  • the gasket 33 is joined to another fuel cell separator, membrane electrode assembly 81 or current collector plate 27A, Close contact with 27B to suppress fluid leakage.
  • the fuel cell separator 23 is a type C fuel cell separator, as shown in FIGS. 4 and 5, in the center of one surface of a rectangular metal plate 30 as a substrate, from the upstream side to the downstream side.
  • a fuel cell gas supply diffusion layer 42 is formed in which cathode gas (fuel cell gas) flows toward and supplies and diffuses the cathode gas.
  • the fuel cell gas supply diffusion layer 42 is a fuel cell gas supply diffusion layer through which the fuel cell gas flows from the upstream side to the downstream side when in use, and transmits and diffuses the fuel cell gas to provide conductivity.
  • the porous body layer 40 is provided.
  • the porous body layer 40 includes a gas diffusion portion 43 made of a porous body, and a plurality of isolated holes 55 that are dispersed and arranged on one surface of the porous body layer 40.
  • Each of the isolated holes 55 is formed in the porous body layer 40 so as to be isolated from each other, and the periphery excluding the opening is surrounded by the gas diffusion portion 43 and includes a recess having the bottom of the porous body.
  • the porous body layer 40 has a gas inflow side groove 51 located at the corner on the inflow side of one surface and a gas outflow side groove 52 located at the corner on the outflow side of one surface (see FIG. 4).
  • the porous body layer 40 may have a gas pressure equalizing groove 56 described later (Modification 7) and a bypass groove 59 described later (Modification 9) as necessary.
  • the flow direction from the upstream side to the downstream side (the direction from the side on the side where the fuel cell gas inlet is provided to the side where the fuel cell gas outlet is provided, Y in FIG.
  • the Y direction is defined as the Y direction
  • the width direction (the direction of the arrow X in FIG. 4) orthogonal to the Y direction in the plan view is defined as the X direction.
  • the gas inflow side groove 51 has a thin rectangular groove part (step part) extending in the width direction at the corner on the inflow side of the porous body layer 40 in plan view. Further, the gas inflow side groove 51 may have a plurality of branch groove portions (branch step portions) branched from the rectangular groove portion (step portion) to the Y direction outflow side so as to correspond to the isolated hole 55. .
  • FIG. 4 illustrates a plurality of branch groove portions (branch step portions) that branch to the outflow side in the Y direction in a shape obtained by cutting a circular isolated hole 55 from a rectangular groove portion (step portion).
  • the gas inflow side groove 51 is formed with a predetermined depth.
  • the gas outflow side groove 52 has a thin rectangular groove part (step part) extending in the width direction at the corner on the outflow side of the porous body layer 40 in plan view. Further, the gas outflow side groove 52 may have a plurality of branch groove portions (branch step portions) branched from the rectangular groove portion (step portion) to the Y direction inflow side so as to correspond to the isolated hole 55. .
  • FIG. 4 illustrates a plurality of branch groove portions (branch step portions) that branch to the Y-direction inflow side in a shape obtained by cutting a circular isolated hole 55 from a rectangular groove portion (step portion).
  • the gas outflow side groove 52 is formed with the same depth as the gas inflow side groove 51.
  • the isolated holes 55 are distributed over a desired range on one surface of the porous body layer 40.
  • Each isolated hole 55 preferably has a shape with a predetermined regularity, and the center of gravity of each isolated hole 55 is preferably disposed on one surface of the porous body layer 40 with a predetermined regularity.
  • the desired range is a range surrounded by a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40 (indicated by reference numeral R in FIG. 4). (A range surrounded by a two-dot chain line).
  • the desired range only needs to cover 60% or more of one surface area of the porous body layer, preferably 70% or more, and more preferably 80% or more.
  • the desired range may be distributed over the entire surface of one surface of the porous body layer 40.
  • the fact that the isolated holes are arranged in a distributed manner does not only mean that the holes are arranged at equal pitches in the X direction and the Y direction. Means that it is arranged.
  • the isolated hole 55 has an area within a desired range (a planar projection range of a range surrounded by a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40. ) Is S1, and the total area of the plurality of isolated holes 55 (the total area of the planar projection areas of the isolated holes for all the isolated holes constituting the plurality of isolated holes 55) is S2. , It is preferably arranged so as to satisfy the relationship of “0.9 ⁇ S1 ⁇ S2 ⁇ 0.1 ⁇ S1”.
  • all the isolated holes 55 may have the same shape and size, or the shape may be changed by changing only the shape. Note that it is preferable that the isolated holes 55 are arranged with regularity at least in a desired range.
  • the shape of the bottom of the isolated hole 55 may be flat in parallel to the membrane electrode assembly 81 or the electrolyte membrane (PEM) 82, or the depth thereof may be different depending on the location.
  • the fuel cell gas supply diffusion layer 42 since the plurality of isolated holes 55 are arranged on one surface of the porous body layer 40, the fuel cell gas flows through the isolated holes 55.
  • the movement resistance is smaller than that flowing down through the gas diffusion part 43 and flows smoothly, a larger amount of fuel cell gas can be supplied to the membrane electrode assembly 81 than in the prior art.
  • the fuel cell gas supply diffusion layer 42 has a plurality of isolated holes 55 formed on one surface of the porous body layer 40, and thus is disposed on the other surface of the porous body layer 40. Since the fuel cell gas is always supplied to the membrane electrode assembly 81 provided through the porous body (gas diffusion portion 43), a plurality of gas flow paths are formed from one surface of the porous body layer 40 to the other. The fuel cell gas can be supplied more uniformly to the membrane electrode assembly than in the case of being formed over the surface.
  • the downstream isolated hole since the periphery of the isolated hole is surrounded by the porous body (gas diffusion portion 43), the downstream isolated hole always proceeds through the porous body (gas diffusion portion 43), so that the porous body is porous.
  • the fuel cell gas can be diffused more uniformly throughout the porous body layer 40 than when the gas flow path is formed in the body layer 40 so as to be connected from the inflow side to the outflow side.
  • the fuel cell gas supply diffusion layer 42 can uniformly supply a larger amount of fuel cell gas to the membrane electrode assembly 81 than in the prior art.
  • the fuel cell gas supply diffusion layer can be improved.
  • the fuel cell gas supply diffusion layer 42 since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, the fuel cell gas (in this case, cathode gas (oxygen gas, nitrogen gas)) not used for power generation is used.
  • the fuel cell gas in this case, cathode gas (oxygen gas, nitrogen gas)
  • the gas can be efficiently discharged out of the fuel cell gas supply diffusion layer 42 through the porous body (gas diffusion portion 43) and the isolated hole 55, the movement resistance of the fuel cell gas is lower than that in the prior art. Therefore, the concentration of the reaction gas is kept high, and the fuel cell gas supply diffusion layer that can increase the power generation efficiency of the fuel cell as compared with the prior art is obtained.
  • the fuel cell gas supply diffusion layer 42 since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation is converted into a porous body (the gas diffusion portion 43). ) And the isolated hole 55, the fuel cell gas supply diffusion layer 42 can be efficiently discharged out of the fuel cell gas supply diffusion layer 42. Therefore, the fuel cell gas supply diffusion layer has better drainage than the conventional one.
  • Each isolated hole 55 may have a shape whose width changes, and may be, for example, a circle, an ellipse, a rhombus, a triangle, or the like when viewed in a plan view. Each isolated hole 55 may be formed at the same depth as the gas inflow side groove 51 and the gas outflow side groove 52 and a constant depth. In each isolated hole 55, the gas diffusion portion 43 made of a porous material is exposed on the inner surface.
  • the fuel cell gas can be two-dimensionally expanded and supplied. .
  • the isolated holes are preferably arranged with regularity in the positional relationship between one isolated hole of the plurality of isolated holes and the isolated hole adjacent to the downstream side of the one isolated hole.
  • the isolated hole 55 has the longest distance along the X direction from one isolated hole 551 among the isolated holes located downstream from one isolated hole 551 among the plurality of isolated holes 55.
  • the first isolated hole having the shortest isolated hole that is, the absolute value of the X direction component of the vector connecting the centroid position of the isolated hole 551 and the centroid position of the adjacent isolated hole is the smallest (including the case where the absolute value is zero).
  • the isolated isolated hole 552 is an isolated hole whose distance along the X direction from the one isolated hole 551 is the second shortest (that is, the X direction component of the vector connecting the gravity center position of the isolated hole 551 and the gravity center position of the adjacent isolated hole) (The isolated hole having the second smallest absolute value) is the second adjacent isolated hole 553, which is the distance between one isolated hole 551 and the first adjacent isolated hole 552, and is the opening of the one isolated hole 551. And the opening of the first adjacent isolated hole 552 The first distance L1 that is the shortest distance between the two and the distance between one isolated hole 551 and the second adjacent isolated hole 553, that is, the opening of the one isolated hole 551 and the second adjacent isolated hole 553.
  • the second interval L2 is in the Y direction.
  • the first adjacent isolated holes 552 that are lined up (the distance along the X direction is the shortest) and the second adjacent isolated holes 553 located in the adjacent rows (both adjacent rows) are close to each other.
  • the distance that passes through the gas diffusion portion 43 when moving from one isolated hole 551 to the second adjacent isolated hole 553 passes through the gas diffusion portion 43 when moving from one isolated hole 551 to the first adjacent isolated hole 552. It should be shorter than the distance.
  • the extruded fuel cell gas is more likely to flow toward the second adjacent isolated hole 553 than to the first adjacent isolated hole 552.
  • the fuel cell gas extruded from the one isolated hole 551 is the first The gas diffuses more widely by moving toward the second adjacent isolated hole 553 rather than toward the adjacent isolated hole 552. Accordingly, the fuel cell gas can be uniformly diffused throughout the porous body layer 40.
  • the first interval L1 and the second interval L2 may further satisfy the relationship “L1 ⁇ 2 ⁇ L2”. That is, since the distance between one isolated hole 551 and the second adjacent isolated hole 553 is the same as the distance between the second adjacent isolated hole 553 and the first adjacent isolated hole 552, the fuel cell gas is one isolated hole 551.
  • the distance passing through the gas diffusion portion 43 when moving directly from the first adjacent isolated hole 552 to the first adjacent isolated hole 552 is as follows. The distance is shorter than the distance passing through the gas diffusion part 43.
  • the distance (first interval L1) that passes through the gas diffusion portion 43 is equal to the fuel cell gas.
  • the distance through the gas diffusion portion 43 (2 ⁇ second interval L2) is shorter. For this reason, the flow of the fuel cell gas from one isolated hole 551 directly toward the first adjacent isolated hole 552 does not extremely decrease, and the fuel cell gas is diffused in a well-balanced manner throughout the porous body layer 40. Can do.
  • the values of the pitch in the X direction and the pitch in the Y direction between the isolated holes are “L2 ⁇ L1 ”and a range satisfying the relationship“ L1 ⁇ 2 ⁇ L2 ”may be set as appropriate.
  • a desired range of area (a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40).
  • the area of the planar projection range of the enclosed range) S1 and the total area S2 of the plurality of isolated holes should be arranged so as to satisfy the relationship of “0.9 ⁇ S1 ⁇ S2 ⁇ 0.1 ⁇ S1”.
  • the reason why is preferable is as follows. That is, when the above S2 is 10% or more of the above S1, the movement resistance when the fuel cell gas flows in a desired range can be made sufficiently small. This is because a large amount of fuel cell gas can be supplied.
  • the area S1 of the porous body layer 40 and the total area S2 of the plurality of isolated holes satisfy the relationship of “S2 ⁇ 0.2 ⁇ S1”. It is more preferable that the relationship of “S2 ⁇ 0.3 ⁇ S1” is satisfied. Further, from the viewpoint of diffusing within a desired range, it is more preferable to satisfy the relationship of “0.8 ⁇ S1 ⁇ S2”, and it is even more preferable to satisfy the relationship of “0.7 ⁇ S1 ⁇ S2”. .
  • the gas diffusion part 43 is made of a porous body having conductivity and having fine voids formed therein.
  • the gas diffusion portion 43 has a substantially rectangular shape when seen in a plan view.
  • the gas diffusion portion 43 is formed with a porosity suitable for allowing a gas or liquid to flow down through this gap. Details will be described later.
  • downstream refers to the gas inflow side groove 51, each isolated hole 55, a gas pressure equalizing groove 56 described later (Modification 7), and a bypass groove 59 described below (Modification 9).
  • “from the gas inflow side to the outflow side” means “approximately along the Y direction in which the gas flows”, and the direction “from the gas inflow side to the outflow side”. Is the direction of flow of the gas in the porous body layer 40 along the Y direction when viewed as the entire porous body layer 40.
  • the cathode gas inlet 62A and the cathode gas outlet 62B are arranged at diagonal positions on the metal plate 30 as in the fuel cell gas supply diffusion layer 42 according to the embodiment.
  • the path does not have to be formed along the above diagonal line, and the direction “from the gas inflow side to the outflow side” as in the embodiment is “a porous body when viewed as the entire porous body layer 40”
  • the direction of the gas flow in the layer 40 is from the bottom to the top in the Y direction in FIG. 4 ”, the bottom direction from the bottom to the top in FIG.
  • the isolated holes 55 may be aligned, and may be aligned along other directions.
  • the porous body layer 40 includes a mixture of a conductive material (preferably a carbon-based conductive material) and a polymer resin.
  • a conductive material preferably a carbon-based conductive material
  • the fluid resistance of the porous body layer 40 depends on the porosity of the porous body layer and the area of the surface through which the fluid flows. As the porosity increases, the fluid resistance decreases. If the area through which the fluid flows increases, the fluid resistance decreases.
  • the porosity of the porous body layer 40 is about 50 to 85%.
  • the porosity of the porous body layer 40 is about 30 to 85%.
  • the porosity of the porous body layer 40 is configured as described above, the cathode gas and water vapor between the isolated hole 55 and the porous body layer 40 via the inner surface of the gas flow channel groove 55.
  • a large amount of fuel cell gas can be supplied uniformly to the membrane electrode assembly.
  • the generated water vapor and condensed water can be efficiently discharged out of the isolated hole.
  • the isolated hole 55 has a gas permeable structure in which a number of fine gas flow holes are opened in the gas impervious layer made of metal, ceramics, resin, or the like on the inner surface of the isolated hole 55. There is no need to form a filter, and the gas diffusion portion 43 made of a porous material is exposed on the inner surface.
  • the porosity of the fuel cell gas supply diffusion layer 42 can be adjusted, and consequently the movement resistance of the fuel cell gas supply diffusion layer 42 can be adjusted. .
  • the content of the carbon-based conductive material is increased, the movement resistance is decreased (the porosity is increased).
  • the content of the carbon-based conductive material is lowered, the movement resistance is increased (the porosity is decreased).
  • the corrosion-resistant layer and the dense frame 32 are also a mixture of a carbon-based conductive material and a polymer resin, and are preferably densified while ensuring conductivity by an appropriate content of the carbon-based conductive material.
  • the carbon-based conductive material is not particularly limited.
  • graphite, carbon black, diamond-coated carbon black, silicon carbide, titanium carbide, carbon fiber, carbon nanotube, and the like can be used.
  • the polymer resin any of a thermosetting resin and a thermoplastic resin can be used. Examples of the polymer resin include phenol resin, epoxy resin, melamine resin, rubber-based resin, furan resin, vinylidene fluoride resin, and the like.
  • An inflow passage 57 is formed between the cathode gas inlet 62A and the region where the porous body layer 40 is formed (see FIG. 4).
  • An outflow passage 58 is formed between the cathode gas outlet 62B and the region where the porous body layer 40 is formed.
  • These inflow passage 57 and outflow passage 58 are for supporting the membrane electrode assembly 81 or its frame 81A. Accordingly, any structure that can smoothly flow the cathode gas and can support the membrane electrode assembly 81 may be used. For example, it may be a porous body layer having a very high porosity or a structure in which a large number of support columns are arranged.
  • An elongated inflow side groove 51 is formed along the width direction of the metal plate 30 in a region facing the inflow passage 57 in the porous body layer 40.
  • An elongated outflow side groove 52 is also formed in the region facing the outflow passage 58 in the porous body layer 40 along the width direction of the metal plate 30.
  • the inflow side groove 51 and the outflow side groove 52 can be omitted.
  • the porous body layer 40, the inflow passage 57, and the outflow passage 58 are formed at the same height (thickness) as the dense frame 32, as shown in FIG.
  • a plurality of isolated holes 55 formed of voids are provided on the surface of the fuel cell gas supply diffusion layer 42 facing the metal plate 30.
  • a plurality of isolated holes 55 and a plurality of metal plates 30 are provided in the gaps between the plurality of isolated holes 55.
  • the gas flow path is formed.
  • a plurality of isolated holes 55 are formed in the arrangement as described above. Each isolated hole 55 diffuses the fuel cell gas that has flowed down through the gas diffusion portion 43 by reducing the movement resistance and flows out to the gas diffusion portion 43 again by forced downflow.
  • the number and structure of the isolated holes 55 are not limited to those illustrated.
  • the width of the porous body layer 40 is, for example, 30 mm, depending on the type and size of the transportation equipment. About 300 mm.
  • the width W of the isolated hole 55 is, for example, about 0.3 mm to 2 mm.
  • the thickness of the porous body layer 40 is, for example, about 150 to 400 ⁇ m, the depth of the isolated hole 55 is, for example, about 100 to 300 ⁇ m, and the distance between the bottom of the isolated hole and the other surface of the porous body layer 40 ( The ceiling thickness is, for example, about 100 to 300 ⁇ m.
  • the size is not limited to the above-described size, and the required performance, etc. Depending on the size, an appropriate size can be used.
  • the fuel cell gas supply diffusion layer 41 in the type A fuel cell separator 22 basically has the same configuration as the fuel cell gas supply diffusion layer 42. However, since the gas supplied to the fuel cell gas supply diffusion layer is hydrogen gas, the porosity is lower and the thickness is smaller than that of the fuel cell gas supply diffusion layer 42 (FIG. 7B described later). reference.).
  • the fuel cell gas supply diffusion layer 41 and the fuel cell gas supply diffusion layer 42 are used as the fuel cell gas supply diffusion layer (see FIG. 7A described later).
  • the type CW fuel cell separator 24 is obtained by forming a cooling water supply diffusion layer on the surface of the type C fuel cell separator 23 where the fuel cell gas supply diffusion layer 42 is not formed. (See 7 (c).)
  • a cooling water supply diffusion layer is formed on the surface of the type A fuel cell separator 22 where the fuel cell gas supply diffusion layer 41 is not formed (see FIG. 7 (d)).
  • protons H +
  • anode gas hydrogen gas
  • Protons diffuse through the membrane electrode assembly 81 and move to the oxygen electrode side, and react with oxygen to produce water.
  • the generated water is discharged from the oxygen electrode side.
  • the air flowing in from the cathode gas inlet 62A passes through the inflow passage 57 and the inflow side groove 51 to the gas diffusion portion 43.
  • the air that has entered and flows down passes through the isolated hole 55 to reduce the distance that it passes through the porous body having a high movement resistance, and thus travels between the isolated holes 55 toward the outflow side.
  • the air that has flowed into the isolated hole 55 spreads into the isolated hole 55, is pushed out again from the inner surface of the isolated hole 55 to the gas diffusion portion 43, is forced downflow, and diffuses in various directions.
  • the air travels between the isolated holes 55 and travels toward the outflow side.
  • the isolated holes 55 are hollow, and the movement resistance of the air is greater than that of the gas diffusion portion 43. Therefore, the air tends to pass through the isolated hole 55 rather than through the gas diffusion portion 43. For this reason, the air pushed out in the plane direction from the one isolated hole 551 to the gas diffusion portion 43 flows down toward the first adjacent isolated hole 552 or the second adjacent isolated hole 553 that is close to the downstream side.
  • the first interval L1 and the second interval L2 satisfy the relationship “L1 ⁇ L2”, the distance (first interval) from the one isolated hole 551 to the second adjacent isolated hole 553 that passes through the gas diffusion portion 43.
  • 2 interval L2) is equal to or shorter than the distance (first interval L1) passing through the gas diffusion part 43 to the first adjacent isolated hole 552, and most of the air pushed out from one isolated hole 551 is in the X direction. And drift down toward the second adjacent isolated hole 553.
  • the air that has flowed into the second adjacent isolated hole 553 is pushed out again to the gas diffusion portion 43 and similarly flows down toward the isolated hole adjacent to the upstream of the second adjacent isolated hole 553. By such repetition, the air travels between the isolated holes 55 toward the outflow side.
  • the gas passes through the gas diffusion portion 43 from one isolated hole 551 to the first adjacent isolated hole 552 directly.
  • the distance (first interval L1) to pass through the gas diffusion portion 43 from one isolated hole 551 to the first adjacent isolated hole 552 via the second adjacent isolated hole 553 is greater than the distance (2 ⁇ second interval L2).
  • the air becomes shorter, and a part of the air flows down along a route from the one isolated hole 551 directly to the first adjacent isolated hole 552.
  • the air diffuses in the thickness direction while diffusing in the plane direction in the porous body layer 40 (gas diffusion portion 43), and the porous body layer 40 (gas diffusion).
  • Gas that has not been used for power generation (unused oxygen gas and nitrogen gas) and water generated during power generation (water vapor or condensed water) pass through the porous body layer 40 (gas diffusion portion 43), the isolated hole 55, and the outflow side groove 52.
  • the oxygen gas, nitrogen gas and water flowing out to the outflow passage 58 are finally discharged from the outflow passage 58 through the cathode gas outlet 62B and the cathode gas outlet 72B.
  • all the water is not discharged and a part of the water stays in the porous body layer 40 (gas diffusion portion 43).
  • the fuel cell gas supply diffusion layer 42 Since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, water (water vapor or condensed water) generated in the membrane electrode assembly during power generation is converted into the porous body layer 40 and the isolated holes. Through 55, it can be efficiently discharged out of the isolated hole. In the downflow region, water can be efficiently discharged out of the isolated hole while being pushed out by the downflow gas flow.
  • the fuel cell gas supply diffusion layer 42 according to the embodiment is used for a fuel cell gas supply diffusion layer for cathode gas, a particularly remarkable effect is obtained.
  • the cathode gas that has not been used for power generation can be efficiently recovered through the gas diffusion portion 43 (porous body) and the isolated hole 55 because it has the characteristics as described above,
  • the fuel cell gas supply diffusion layer can further increase the power generation efficiency of the fuel cell as compared with the prior art.
  • it since it has the above characteristics, it is possible to efficiently recover the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation via the gas diffusion portion 43 (porous body) and the isolated hole 55. Therefore, the fuel cell gas supply diffusion layer is superior in drainage than the conventional one.
  • the fuel cell gas supply diffusion layer 42 according to the embodiment is particularly effective when the cathode gas is air. In this case, since it has the characteristics as described above, nitrogen gas that is not used for power generation can be efficiently discharged through the gas diffusion portion 43 (porous body) and the isolated hole 55.
  • the fuel cell gas supply diffusion layer can reduce the movement resistance of the fuel cell gas and can further increase the power generation efficiency of the fuel cell as compared with the conventional one.
  • the fuel cell separator 23 is a fuel cell separator including a metal plate 30 and a fuel cell gas supply diffusion layer disposed on at least one surface of the metal plate 30.
  • the gas supply diffusion layer is the fuel cell gas supply diffusion layer 42 according to the embodiment, and the fuel cell gas supply diffusion layer 42 is made of metal such that the plurality of gas flow channel grooves 55 are located on the metal plate 30 side. Since the gas flow path is constituted by the gas flow path groove 55 and the metal plate 30, it is possible to increase the power generation efficiency of the fuel cell as compared with the prior art.
  • the fuel cell separator is excellent in drainage.
  • the fuel cell stack 20 according to the embodiment is a fuel cell stack in which a fuel cell separator and a membrane electrode assembly are stacked, and the fuel cell separator is the fuel cell stack according to the embodiment.
  • the separator 23 for the fuel cell and the membrane electrode assembly 81 are the membrane electrode assembly on the surface of the fuel cell gas supply diffusion layer 42 where the plurality of gas flow channel grooves 55 are not formed. Since the layers 81 are stacked in a positional relationship, the fuel cell power generation efficiency can be increased as compared with the conventional case, and further, the fuel cell stack can be more excellent in drainage than the conventional case.
  • the corrosion-resistant layer, the dense frame 32, the fuel cell gas supply diffusion layer 42, and the like are formed by isotropic pressure.
  • a thermosetting resin a thermoplastic resin may be used
  • carbon-based conductive material powder and carbon fiber depending on the situation
  • resin powder and volatile solvent are kneaded to form a paste.
  • Many types of pastes such as a corrosion-resistant layer, a dense frame, and a fluid supply diffusion layer, are prepared.
  • a corrosion-resistant layer, a dense frame 32 pattern, a fuel cell gas supply diffusion layer 42 pattern, and the like are sequentially formed on the metal plate 30 by printing, stamping, squeezing, and the like.
  • the solvent is volatilized for each pattern formation.
  • the whole metal plate 30 on which all the above patterns are formed is put in a soft thin rubber bag, degassed to a vacuum, and then the rubber bag is put in a pressure vessel, and a heating fluid is introduced into the vessel. Press the isotropic pressure to cure the resin.
  • the height (thickness) of the dense frame 32 and the fuel cell gas supply diffusion layer 42 the same height (thickness)
  • each of these may be selected according to the degree of shrinkage during resin curing. It is preferable to adjust the height (thickness) of the frame, wall, layer, and the like at the time of pattern formation.
  • a corrosion-resistant layer can be formed on the metal plate 30, the dense frame 32 and the fuel cell gas supply diffusion layer 42 can be formed on the other side, and finally these can be manufactured by thermocompression bonding.
  • the dense frame 32 may be formed simultaneously with the corrosion-resistant layer on the metal plate 30.
  • a corrosion-resistant layer and a dense frame 32 are formed on the metal plate 30, and then in the second stage, the paste of the fuel cell gas supply diffusion layer 42 is sequentially printed on the corrosion-resistant layer of the metal plate 30 and dried. After making it harden
  • the following manufacturing method can be used. Green before being cured by kneading carbon fiber (CF), a small amount of black smoke fine particles (GCB), and a thermoplastic or thermosetting resin as a binder or a resin that forms a fibrous material into a sheet.
  • CF carbon fiber
  • GCB black smoke fine particles
  • thermoplastic or thermosetting resin as a binder or a resin that forms a fibrous material into a sheet.
  • a stamp mold having a shape corresponding to the inflow passage 57, the outflow passage 58, the inflow side groove 51, the outflow side groove 52, and the isolated hole 55 is pressed against the sheet, and the inflow passage 57, the outflow passage 58, An inflow side groove 51, an outflow side groove 52, and an isolated hole 55 are formed.
  • the green sheet is heat treated and bonded to the metal plate 30 on which the corrosion resistant layer is formed.
  • the movement resistance (or fluid resistance) of the fuel cell gas supply diffusion layer 42 is the surface area (height (thickness) and width of each layer) orthogonal to the porosity of the porous body layer 40 and the fluid flow direction. Dependent. If the porosity increases, the movement resistance decreases. If the area through which the fluid flows increases, the movement resistance decreases (the movement resistance per unit area is constant).
  • the porosity of the fuel cell gas supply diffusion layer is about 30 to 85% for the fuel cell gas supply diffusion layer 42 (for the anode gas), and the fuel cell gas supply diffusion for the cathode gas.
  • the layer 41 is about 50 to 85%.
  • the manufacturing method described above is also used when manufacturing fuel cell separators other than the fuel cell separator 23 (fuel cell separator 21, fuel cell separator 22, fuel cell separator 24, and fuel cell separator 25). Applicable.
  • FIG. 7 is a cross-sectional view of a fuel cell separator (a fuel cell separator 21, a fuel cell separator 22, a fuel cell separator 24, and a fuel cell separator 25) other than the fuel cell separator 23.
  • 7A is a sectional view of a fuel cell separator 21 of type CA
  • FIG. 7B is a sectional view of a fuel cell separator 22 of type A
  • FIG. 7C is a fuel of type CW.
  • FIG. 7D is a cross-sectional view of a battery separator 24, and
  • FIG. 7D is a cross-sectional view of a fuel cell separator 25 of type AW.
  • the fuel cell gas supply diffusion layer of the present invention is applied to the fuel cell gas supply diffusion layer (for cathode gas) 42 and / or the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 21. (See FIG. 7 (a)). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 22 (see FIG. 7B). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 42 (for cathode gas) of the fuel cell separator 24 (see FIG. 7c). ). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 25 (see FIG. 7B).
  • the fuel cell gas supply diffusion layer of the present invention is applied to the fuel cell gas supply diffusion layers of the fuel cell separators 21, 22, 24, and 25 as described above, a larger amount than in the conventional case. Since the fuel cell gas can be uniformly supplied to the membrane electrode assembly, it becomes a fuel cell gas supply diffusion layer that can increase the power generation efficiency of the fuel cell as compared with the conventional case.
  • FIG. 4 As an embodiment of the present invention, a configuration example of a fuel cell gas supply diffusion layer as shown in FIG. 4 can be shown. That is, in FIG. 4, in addition to the basic configuration as described above, as a predetermined regularity, on a plurality of lines extending in the Y direction arranged at equal pitch (X pitch) in the X direction, equal pitch (Y pitch) in the Y direction. Is arranged in. If the isolated holes 55 are arranged in the Y direction as one column and n columns from the end in the X direction, the positions of the odd columns and the even columns in the Y direction are the same. The position is shifted by half the Y pitch (so-called staggered pattern configuration).
  • each isolated hole 55 has the same shape including shape and size, and each isolated hole 55 is arranged on one surface of the porous body layer 40.
  • Each isolated hole 55 has a shape that changes in width, and specifically has a circular shape.
  • Each isolated hole 55 is formed with the same depth as the gas inflow side groove 51 and the gas outflow side groove 52 and a constant depth.
  • the gas diffusion portion 43 made of a porous body is exposed on the inner surface.
  • the plurality of isolated holes 55 are dispersed over the entire surface of one surface of the porous body layer 40, so that the fuel cell gas is more spread over the entire porous body layer 40. It can be diffused uniformly.
  • FIG. 8 is a view for explaining a planar structure (seen from the metal plate 30 side) of the fuel cell gas supply diffusion layer 42a according to the first modification.
  • the metal plate 30 is not shown in order to easily show the flow path pattern of the fuel cell separator 23. The same applies to the following FIG. 9 to FIG.
  • the fuel cell gas supply diffusion layer 42a according to Modification 1 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 8, in the fuel cell gas supply diffusion layer 42 a according to the first modification, an isolated hole 55 a having a rhombic planar shape is used as the isolated hole.
  • the isolated hole 55a has a flat wall surface, and the wall surfaces of the adjacent isolated holes 55a can be arranged in parallel, so that the fluid resistance between the isolated holes 55a becomes constant over a wide range.
  • the fuel cell gas can be more uniformly downflowed.
  • FIG. 9 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42b according to the second modification.
  • the fuel cell gas supply diffusion layer 42b according to Modification 2 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 9, in the fuel cell gas supply diffusion layer 42b according to the modified example 2, the isolated hole is a planar shape having a constant width as an isolated hole (in this case, a rectangle extending along the Y direction). 55b is used.
  • the fuel cell gas supply diffusion layer 42b according to Modification 2 in addition to the same effects as the fuel cell gas supply diffusion layer 42 according to the embodiment, the following effects can be obtained. That is, since the width of the isolated hole 55b is constant, that is, the planar shape is square or rectangular, the isolated hole 55b is formed on the entire one surface of the porous body layer, particularly when the planar shape of the porous body layer is rectangular. Easy to place over.
  • FIG. 10 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42c according to the third modification.
  • the fuel cell gas supply diffusion layer 42c according to the modified example 3 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 10, in the fuel cell gas supply diffusion layer 42 c according to Modification 3, an isolated hole 55 c that is an isolated groove extending along an oblique direction is used as the isolated hole.
  • the fuel cell gas supply diffusion layer 42c according to the modified example 3 in addition to the same effects as the fuel cell gas supply diffusion layer 42 according to the embodiment, the following effects can be obtained. That is, since the isolated hole 55c is an isolated groove extending along an oblique direction, the fuel cell gas can be expanded in the X direction and advanced in the Y direction.
  • FIG. 11 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42d according to Modification 4.
  • the fuel cell gas supply diffusion layer 42d according to Modification 4 has basically the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 11, in the fuel cell gas supply diffusion layer 42d according to Modification 4, an isolated hole 55d that is bent in the middle is used as the isolated hole. Examples of the shape of the isolated hole 55d that is bent in the middle include, for example, U-shape, C-shape, arc shape, and the like in addition to the L-shape as shown in FIG.
  • the isolated holes 55d are intermittently arranged along a zigzag line represented by a two-dot chain line G in FIG.
  • the isolated hole 55d is bent in the middle. As a result, it is possible to obtain an effect that the fuel cell gas can be quickly changed in direction and spread.
  • FIG. 12 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42e according to the fifth modification.
  • the fuel cell gas supply diffusion layer 42e according to the modification 5 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the planar structure of the isolated hole is the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 12, in the fuel cell gas supply diffusion layer 42e according to the modified example 4, the isolated hole 55e is formed in such a manner that the area seen in a plane is gradually reduced as it goes downstream. ing.
  • FIG. 12 shows an example in which rectangular isolated holes are formed in the same manner as that shown in FIG.
  • the length (width) in the X direction of the rectangular isolated hole 55e is formed so as to be gradually reduced as W1> W2> W3.
  • the following effects can be obtained. That is, as the isolated hole 55e goes to the downstream side, the area seen in a plan view becomes smaller in steps, so that it corresponds to the flow rate of the fuel cell gas decreasing toward the downstream side. For this reason, the concentration of the fuel cell gas on the upstream side and the downstream side becomes more uniform, and the fuel cell gas can be diffused efficiently.
  • FIG. 13 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42f according to Modification 6.
  • the fuel cell gas supply diffusion layer 42f according to the modification 6 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the planar structure of the isolated hole is changed to the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 13, the fuel cell gas supply diffusion layer 42 f according to the modified example 6 is formed so that the area seen in a plane is gradually reduced as the isolated hole 55 f goes downstream. ing.
  • FIG. 13 shows an example in which a rectangular isolated hole 55e is configured in the same manner as that shown in FIG. Here, as the isolated hole 55f moves from the inflow side to the outflow side, the length of the rectangular isolated hole 55e in the Y direction is gradually reduced as D1> D2> D3.
  • the following effects can be obtained. That is, since the area seen in a plan view decreases stepwise as the isolated hole 55f goes downstream, it corresponds to the flow rate of the fuel cell gas that decreases as it goes downstream. For this reason, the concentration of the fuel cell gas on the upstream side and the downstream side becomes more uniform, and the fuel cell gas can be diffused efficiently.
  • each of the isolated holes is shown as a rectangular isolated hole (55e, 55f).
  • the size (area) of the isolated hole is reduced as it goes downstream.
  • the isolated hole may have another shape such as a circle, an ellipse, a diamond, or a triangle. Moreover, it is good also as an optimal shape for every isolated hole.
  • FIG. 14 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42g according to Modification 7.
  • the fuel cell gas supply diffusion layer 42g according to the modified example 7 basically has the same configuration as the fuel cell gas supply diffusion layer 42b according to the modified example 2, but further includes a gas pressure equalizing groove. This is different from the fuel cell gas supply diffusion layer 42b according to the second modification. That is, as shown in FIG. 14, in the fuel cell gas supply diffusion layer 42g according to the modified example 7, the porous body layer 40 is formed on one surface of the porous body layer 40 on the width of the porous body layer 40.
  • One or more gas pressure equalizing grooves 56 are further provided. The gas pressure equalizing grooves 56 are formed at two locations so as to divide the porous body layer 40 into approximately three equal parts in the Y direction.
  • the gas pressure equalizing groove 56 is formed with a depth equivalent to that of the isolated hole 55g. Since the gas pressure equalizing groove 56 is provided, the isolated hole 55g has the gas pressure equalizing grooves 56, the inflow side groove 51 and the gas pressure equalizing groove 56 in one surface of the porous body layer 40, or Dispersed and arranged over a range (desired range) sandwiched between the outflow side groove 52 and the gas pressure equalizing groove 56.
  • the width direction of the porous body layer 40 can be obtained.
  • the supply amount of the fuel cell gas can be made more uniform over the entire width direction of the porous body layer 40.
  • FIG. 15 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42h according to Modification 8.
  • the fuel cell gas supply diffusion layer 42h according to the modified example 8 has basically the same configuration as the fuel cell gas supply diffusion layer 42g according to the modified example 7, but the number of gas pressure equalization grooves and the isolation are isolated.
  • the planar structure of the holes is different from that of the fuel cell gas supply diffusion layer 42g according to the modified example 7. That is, as shown in FIG. 15, in the fuel cell gas supply diffusion layer 42h according to the modification 8, only one gas pressure equalizing groove 56 is formed. Further, in the fuel cell gas supply diffusion layer 42h according to the modified example 8, as the plurality of isolated holes 55h go to the downstream side, the intervals between the isolated holes adjacent in the width direction (X direction) are gradually reduced. It has become.
  • the interval P2 between the isolated holes 55h on the downstream side of the gas pressure equalizing groove 56 is narrower than the interval P2 between the isolated holes 55h on the upstream side of the gas pressure equalizing groove 56.
  • the isolated hole 55 h has a narrower width on the downstream side of the gas pressure equalizing groove 56 than a width on the upstream side of the gas pressure equalizing groove 56.
  • the gas pressure equalizing groove 56 since the gas pressure equalizing groove 56 is provided as one example, the isolated hole 55h has the inflow side groove 51 and the gas pressure equalizing groove 56 in one surface of the porous body layer 40.
  • the arrangement rules are arranged separately from each other.
  • the following effects can be obtained. That is, since the interval between the isolated holes 55h adjacent to each other in the X direction is gradually reduced, the number of isolated holes 55h aligned in the direction along the X direction is increased stepwise. For this reason, even if the pressure loss increases toward the downstream side, the fuel cell gas flowing down and the water vapor or condensed water generated in the membrane electrode assembly at the time of power generation are in close contact with the downstream isolated holes.
  • the fuel cell gas is more easily diffused, and the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation can be discharged out of the fuel cell gas supply diffusion layer 42h more efficiently. Further, the fuel cell gas can be diffused more uniformly downstream of the gas pressure equalizing groove 56.
  • FIG. 16 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42i according to Modification 9.
  • the fuel cell gas supply diffusion layer 42i according to the modification 9 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but is further modified in that it further includes a bypass groove. This is different from the case of the fuel cell gas supply diffusion layer 42b according to No. 2. That is, as shown in FIG. 16, in the fuel cell gas supply diffusion layer 42i according to the modified example 9, the porous body layer 40 is disposed on one surface of the porous body layer 40 on the inflow side of the fuel cell gas. Further, a bypass groove 59 (inflow bypass groove 59A) extending from the center to the center is further provided. In the fuel cell gas supply diffusion layer 42i according to the modified example 9, the porous body layer 40 includes a bypass groove 59 (outflow bypass groove) extending from the central portion to the outflow side of the fuel cell gas. 59B).
  • Each bypass groove 59 is a groove in which thin rectangular portions are combined.
  • Each bypass groove 59 (59A, 59B) is formed with the same depth as the inflow side groove 51 or the outflow side groove 52 which communicates.
  • the inflow bypass groove 59A is formed by combining a feed groove portion 591A, a widening groove portion 592A, and a plurality of branch groove portions 593A.
  • the inflow side of the feed groove portion 591A is connected to the vicinity of one end portion in the X direction of the inflow side groove 51, and extends from the inflow side groove 51 to the center of the porous body layer 40 in the Y direction.
  • the widening groove portion 592A extends in the X direction from the distal end side of the feed groove portion 591A.
  • a plurality of branch groove portions 593A extend from the widened groove portion 592A to the outflow side in the Y direction so as to correspond to the continuous pattern shape of the isolated holes 55i.
  • the outflow bypass groove 59B is formed by combining a feed groove portion 591B, a widening groove portion 592B, and a plurality of branch groove portions 593B.
  • the feed groove portion 591 ⁇ / b> B is connected to the vicinity of the other end portion in the X direction of the outflow side groove 52 on the outflow side, and extends in the Y direction from the outflow side groove 52 to the center of the porous body layer 40.
  • the widening groove portion 592B extends in the X direction from the leading end side of the feed groove portion 591B.
  • a plurality of branch groove portions 593B extend from the widened groove portion 592B to the inflow side in the Y direction so as to correspond to the continuous pattern shape of the isolated holes 55i.
  • the widening groove portion 592A in the inflow bypass groove 59A is disposed on the outflow side of the widening groove portion 592B in the outflow bypass groove 59B.
  • the widening groove portion 592A in the inflow bypass groove 59A extends in the X direction to the extent that it does not intersect the feed groove portion 591B in the outflow bypass groove 59B.
  • the widening groove portion 592B in the outflow bypass groove 59B expands in the X direction to the extent that it does not intersect the feed groove portion 591A in the inflow bypass groove 59A.
  • channel 52 and the widening groove part 592B are comprised.
  • the fuel cell gas flows separately into a first block and a second block. Therefore, the fuel cell gas passing through both blocks is almost zero.
  • an isolated hole 55i is arranged in this block, that is, for each range (desired range) sandwiched between the inflow side groove 51 and the widening groove portion 592B, or between the outflow side groove 52 and the widening groove portion 592B. Yes.
  • the size and shape of the isolated holes 55i and the arrangement rule of the distributed arrangement may be arranged separately.
  • the porous body layer 40 has a bypass groove 59 (an inflow bypass groove 59A) extending from the fuel cell gas inflow side to the center portion, so that the porous body layer 40 decreases upstream from the center portion. Since the fuel cell gas that has been supplied is replenished in the central portion, it is possible to suppress a decrease in power generation efficiency downstream from the central portion. Further, the porous body layer 40 has a bypass groove 59 (outflow bypass groove 59B) extending from the central portion to the outflow side of the fuel cell gas, so that it is upstream of the central portion. Since water vapor or condensed water generated in the membrane electrode assembly 81 during power generation is efficiently discharged from the central portion, it is possible to suppress a decrease in power generation efficiency downstream from the central portion.
  • one isolated hole 551a to 551i one isolated hole 551h1, 551h2 in the modified example 8) and the first adjacent isolated hole 552a to 552i (first proximity isolated holes 552h1 and 552h2 in the modified example 8)
  • the first interval L1 first intervals L11 and L12 in the modified example 8
  • one isolated hole 551a to 551i one isolated hole 551a to 551i and the second adjacent isolated hole 553a to 553i.
  • the second interval L2 (the second intervals L12 and L22 in the modified example 8) of the second adjacent isolated holes 553h1 and 553h2 in the modified example 8 is “L2 ⁇ L1” and “L1” as in the case of the embodiment. ⁇ 2 ⁇ L2 ”is satisfied.
  • the one isolated hole 551c, 551d extends along the X direction.
  • the third shortest distance or the second shortest isolated hole equivalent to the second adjacent isolated hole 553c, 553d that is, the vector X connecting the centroid position of the isolated hole 551c, 551d and the centroid position of the adjacent isolated hole.
  • An isolated hole whose absolute value of the direction component is the third smallest or the second smallest isolated hole equivalent to other isolated holes) is depicted as third adjacent isolated holes 554c and 554d.
  • the distance between the one isolated hole 551c, 551d and the third adjacent isolated hole 554c, 554d is not particularly limited, but is preferably shorter than the first distance L1 so as to diffuse more widely.
  • FIG. 17 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42j according to Modification 10.
  • 18 is a cross-sectional view taken along line EE in FIG.
  • the fuel cell gas supply diffusion layer 42j according to the modification 10 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the bottom shape of the isolated hole is the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 18, in the fuel cell gas supply diffusion layer 42j according to the modified example 10, the isolated holes are inclined so that the bottom surfaces of the isolated holes become deeper as they go downstream as isolated holes. 55j is used. In the modification 10, an example in which the rectangular isolated holes 55j are used in the plan view is shown, but at this time, the size and shape of the isolated holes 55j and the arrangement rule of the distributed arrangement are changed to other modified examples. As such, it may be arbitrarily changed.
  • the bottom surface of each isolated hole is located on the downstream side. Therefore, the flow of the fuel cell gas flowing in each isolated hole 55j includes a vector directed to the membrane electrode assembly 81. For this reason, the fuel cell gas flowing down from the isolated hole 55j is further directed to the membrane electrode assembly 81, and an effect that more fuel cell gas can be supplied to the membrane electrode assembly 81 is also obtained.
  • FIG. 19 is a cross-sectional view of a fuel cell gas supply diffusion layer 42k according to Modification 11.
  • the fuel cell separator 23 k in a state where the membrane electrode assembly 81 is joined is shown.
  • the fuel cell gas supply diffusion layer 42 including the porous body layer 40 having a plurality of isolated holes 55 formed on one surface is used as the fuel cell gas supply diffusion layer (see FIG. 5), the present invention is not limited to this.
  • a battery gas supply diffusion layer can also be used.
  • a fuel cell separator can be configured using a membrane electrode assembly that does not include a microporous layer.
  • the width of the isolated hole on the surface of the porous body layer 40 is equal to the width of the gas channel groove at the bottom of the isolated hole 55.
  • the isolated hole 55 having a rectangular cross section is used (see FIGS. 5 and 7), the present invention is not limited to this.
  • An isolated hole with a triangular cross section narrower than the surface of the groove may be used, or an isolated hole with a semicircular cross section with a bottom of the groove narrower than the surface may be used. It may be used.
  • the metal plate 30 is used as the gas shielding plate, but the present invention is not limited to this.
  • a plate for example, a ceramic plate or a resin plate
  • a material having a property of shielding gas other than the metal plate 30 may be used.
  • the characteristics described in each modification are applied to the fuel cell gas supply diffusion layer 42, the fuel cell separator 23, and the fuel cell stack 20 according to the embodiment.
  • the features described in each modification are not limited to this, and can be applied to the fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack of the present invention.
  • the characteristics described in each of the modified examples are that the gas supply diffusion layer 21 for fuel cells of type CA, the gas supply diffusion layer 22 for fuel cells of type A, the gas supply diffusion layer 24 for fuel cells of type CW, and the type AW
  • the present invention is also applicable to the fuel cell gas supply diffusion layer 25, and the fuel cell separator and fuel cell stack provided with these fuel cell gas supply diffusion layers.
  • the isolated holes 55 having the same shape to some extent are arranged at a constant pitch in the X direction.
  • a plurality of types of isolated holes having completely different shapes may be combined, or may be arranged so that the pitch in the X direction changes.
  • the present invention is not limited to this.
  • the depth of the isolated hole or groove may be different for each isolated hole or groove, or may vary within the isolated hole or groove.
  • the features described in each modification are applied to the fuel cell gas supply diffusion layer 42, the fuel cell separator 23, and the fuel cell stack 20 according to the embodiment.
  • the features described in each modification are not limited to this, and can be applied to the fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack of the present invention.
  • the characteristics described in each of the modified examples are that the gas supply diffusion layer 21 for fuel cells of type CA, the gas supply diffusion layer 22 for fuel cells of type A, the gas supply diffusion layer 24 for fuel cells of type CW, and the type AW
  • the present invention is also applicable to the fuel cell gas supply diffusion layer 25, and the fuel cell separator and fuel cell stack provided with these fuel cell gas supply diffusion layers.

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Abstract

In this gas supply diffusion layer 42 for a fuel cell, gas for a fuel cell flows from upstream to downstream during use. The gas supply diffusion layer for a fuel cell is characterized: by comprising a conductive porous body layer 40 that transmits and diffuses gas for a fuel cell; in that the porous body layer 40 has a gas diffusion section 43 made of a porous body, and a plurality of isolated holes 55 arranged so as to be dispersed in one surface of the porous body layer 40; in that the isolated holes are formed in the porous body layer 40 so as to be isolated from each other; in that the periphery of the isolated holes, excluding the opening, is surrounded by the gas diffusion section 43; and in that each of the isolated holes is composed of a recess having a bottom made of a porous body. This gas supply diffusion layer 42 for a fuel cell enables greater fuel-cell power generation efficiency than was previously possible.

Description

燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックGas supply diffusion layer for fuel cell, fuel cell separator and fuel cell stack
　本発明は、燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックに関する。 The present invention relates to a gas supply diffusion layer for fuel cells, a separator for fuel cells, and a fuel cell stack.
　固体高分子形燃料電池（ＰＥＦＣ：Polymer Electrolyte Fuel Cell）の技術分野において、燃料電池用ガス（アノードガス、カソードガス）を均一に供給及び拡散させることが可能な燃料電池セルスタックが知られている（例えば、特許文献１参照。）。図２０は、従来の燃料電池セルスタック９２０を模式的に示す正面図である。図２１及び図２２は、従来の燃料電池セルスタック９２０におけるタイプＣＡのセパレータ９２１の平面図である。このうち図２１は燃料電池用ガス供給拡散層（カソードガス供給拡散層）９４２側から見た平面図であり、図２２は燃料電池用ガス供給拡散層（アノードガス供給拡散層）９４１側から見た平面図である。図２３は、図２１のＡ－Ａ線に沿った断面図である。 In the technical field of polymer electrolyte fuel cells (PEFC), fuel cell stacks that can uniformly supply and diffuse fuel cell gases (anode gas and cathode gas) are known. (For example, refer to Patent Document 1). FIG. 20 is a front view schematically showing a conventional fuel cell stack 920. 21 and 22 are plan views of a type CA separator 921 in a conventional fuel cell stack 920. FIG. 21 is a plan view of the fuel cell gas supply diffusion layer (cathode gas supply diffusion layer) 942 side, and FIG. 22 is a fuel cell gas supply diffusion layer (anode gas supply diffusion layer) 941 side. FIG. FIG. 23 is a sectional view taken along line AA in FIG.
　従来の燃料電池セルスタック９２０は、図２０～図２３に示すように、金属板３０の少なくとも一方の面に多孔質体層による燃料電池用ガス供給拡散層が設けられた構造の複数のセパレータ（タイプＣＡのセパレータ９２１、タイプＡのセパレータ９２２、タイプＣのセパレータ９２３、タイプＡＷのセパレータ９２４）が積層された構造を有する。なお、タイプＣＡのセパレータ９２１、タイプＡのセパレータ９２２及びタイプＡＷのセパレータ９２４の「Ａ」は燃料電池用ガス供給拡散層（アノードガス供給拡散層）９４１を表し、タイプＣＡのセパレータ９２１及びタイプＣのセパレータ９２３の「Ｃ」は燃料電池用ガス供給拡散層（カソードガス供給拡散層）９４２を表し、タイプＡＷのセパレータ９２４の「Ｗ」は冷却水供給拡散層を表す。従来の燃料電池セルスタック９２０によれば、セパレータそのものに多孔質体層からなる燃料電池用ガス供給拡散層９４１，９４２が形成されていることから、燃料電池用ガスを燃料電池用ガス供給拡散層の全面にわたって均一に拡散できる。その結果、燃料電池用ガスを膜電極接合体（ＭＥＡ）８１の全面にわたって均一に供給でき、燃料電池の発電効率を従来よりも高くできる。 As shown in FIGS. 20 to 23, a conventional fuel cell stack 920 includes a plurality of separators having a structure in which a fuel cell gas supply diffusion layer is provided on at least one surface of a metal plate 30 as a porous body layer. A type CA separator 921, a type A separator 922, a type C separator 923, and a type AW separator 924) are stacked. “A” in the type CA separator 921, the type A separator 922, and the type AW separator 924 represents the gas supply diffusion layer (anode gas supply diffusion layer) 941 for the fuel cell, and the type CA separator 921 and type C. “C” of the separator 923 of FIG. 5 represents a fuel cell gas supply diffusion layer (cathode gas supply diffusion layer) 942, and “W” of the type AW separator 924 represents a cooling water supply diffusion layer. According to the conventional fuel cell stack 920, the fuel cell gas supply diffusion layers 941 and 942 formed of the porous body layer are formed on the separator itself, so that the fuel cell gas is supplied to the fuel cell gas supply diffusion layer. Can diffuse uniformly over the entire surface. As a result, the fuel cell gas can be supplied uniformly over the entire surface of the membrane electrode assembly (MEA) 81, and the power generation efficiency of the fuel cell can be increased as compared with the conventional case.
国際公開第２０１５／０７２５８４号International Publication No. 2015/072584
　ところで、燃料電池の技術分野においては、従来よりも燃料電池の発電効率を高くできる技術が求められており、固体高分子形燃料電池の技術分野においても同様である。そこで、本発明は、従来よりも燃料電池の発電効率を高くできる、燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックを提供することを目的とする。 By the way, in the technical field of fuel cells, there is a demand for a technology capable of increasing the power generation efficiency of the fuel cell as compared with the conventional technology, and the same applies to the technical field of polymer electrolyte fuel cells. Therefore, an object of the present invention is to provide a fuel cell gas supply diffusion layer, a fuel cell separator, and a fuel cell stack, which can increase the power generation efficiency of the fuel cell as compared with the prior art.
　本発明の一態様による燃料電池用ガス供給拡散層は、使用時に上流から下流側に向かって燃料電池用ガスが流れる燃料電池用ガス供給拡散層であって、前記燃料電池用ガスを透過、拡散し、導電性を有する多孔質体層を備え、前記多孔質体層は、多孔質体からなるガス拡散部と、前記多孔質体層の一方の面に分散して配置された複数の孤立穴とを有し、前記孤立穴の各々は、互いに孤立して前記多孔質体層に形成され、開口部を除く周囲が前記ガス拡散部に囲まれ、多孔質体の底を有する凹部からなる。 A fuel cell gas supply diffusion layer according to an aspect of the present invention is a fuel cell gas supply diffusion layer through which fuel cell gas flows from upstream to downstream during use, and transmits and diffuses the fuel cell gas. And a porous body layer having conductivity, the porous body layer comprising a gas diffusion portion made of a porous body, and a plurality of isolated holes arranged dispersed on one surface of the porous body layer Each of the isolated holes is formed in the porous body layer so as to be isolated from each other, and the periphery excluding the opening is surrounded by the gas diffusion portion and includes a recess having a bottom of the porous body.
　本発明の一実態様による燃料電池用セパレータは、ガス遮蔽板と、前記ガス遮蔽板の少なくとも一方の面に配設された燃料電池用ガス供給拡散層とを備える燃料電池用セパレータであって、前記燃料電池用ガス供給拡散層は、本発明の燃料電池用ガス供給拡散層であり、前記燃料電池用ガス供給拡散層は、前記複数の孤立穴が前記ガス遮蔽板側に位置するように前記ガス遮蔽板に対して配置されており、前記孤立穴と前記ガス遮蔽板とでガス流路が構成されている。 A fuel cell separator according to an embodiment of the present invention is a fuel cell separator comprising a gas shielding plate and a fuel cell gas supply diffusion layer disposed on at least one surface of the gas shielding plate, The fuel cell gas supply diffusion layer is a fuel cell gas supply diffusion layer according to the present invention, and the fuel cell gas supply diffusion layer has the plurality of isolated holes positioned on the gas shielding plate side. It arrange | positions with respect to the gas shielding board, and the gas flow path is comprised by the said isolated hole and the said gas shielding board.
　本発明の一態様による燃料電池セルスタックは、燃料電池用セパレータと、膜電極接合体とが積層されてなる燃料電池セルスタックであって、前記燃料電池用セパレータは、本発明の燃料電池用セパレータであり、前記燃料電池用セパレータと前記膜電極接合体とは、前記燃料電池用ガス供給拡散層の前記複数の孤立穴が形成されていない側の面に前記膜電極接合体が位置する位置関係で積層されている。 A fuel cell stack according to an aspect of the present invention is a fuel cell stack formed by laminating a fuel cell separator and a membrane electrode assembly, and the fuel cell separator is the fuel cell separator of the present invention. The fuel cell separator and the membrane electrode assembly are in a positional relationship in which the membrane electrode assembly is positioned on the surface of the fuel cell gas supply diffusion layer where the plurality of isolated holes are not formed. Are stacked.
　本発明の一態様による燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックによれば、従来よりも燃料電池の発電効率を高くでき、さらには、従来よりも排水性に優れた、燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックとなる。 According to the fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack according to one aspect of the present invention, the power generation efficiency of the fuel cell can be increased as compared with the conventional case, and further, the drainage performance is superior as compared with the conventional case. A fuel cell gas supply diffusion layer, a fuel cell separator, and a fuel cell stack.
実施形態に係る燃料電池セルスタック２０を模式的に示す正面図である。It is a front view showing typically fuel cell stack 20 concerning an embodiment. 実施形態に係る燃料電池セルスタック２０を模式的に示す側面図である。It is a side view showing typically fuel cell stack 20 concerning an embodiment. 膜電極接合体（ＭＥＡ）８１を説明するために示す図である。It is a figure shown in order to demonstrate the membrane electrode assembly (MEA) 81. FIG. 実施形態に係る燃料電池用セパレータ２３の平面図である。It is a top view of the separator 23 for fuel cells which concerns on embodiment. 図４の断面図である。FIG. 5 is a cross-sectional view of FIG. 4. 燃料電池用ガスの流れを説明するために示す図である。It is a figure shown in order to demonstrate the flow of the gas for fuel cells. 燃料電池用セパレータ２３以外の燃料電池用セパレータ（燃料電池用セパレータ２１，２２，２４，２５）の断面図である。4 is a cross-sectional view of a fuel cell separator ( fuel cell separators 21, 22, 24, 25) other than the fuel cell separator 23. FIG. 変形例１に係る燃料電池用ガス供給拡散層４２ａの平面図である。7 is a plan view of a fuel cell gas supply diffusion layer 42a according to Modification 1. FIG. 変形例２に係る燃料電池用ガス供給拡散層４２ｂの平面図である。10 is a plan view of a fuel cell gas supply diffusion layer 42b according to Modification 2. FIG. 変形例３に係る燃料電池用ガス供給拡散層４２ｃの平面図である。14 is a plan view of a fuel cell gas supply diffusion layer 42c according to Modification 3. FIG. 変形例４に係る燃料電池用ガス供給拡散層４２ｄの平面図である。FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42d according to Modification 4. 変形例５に係る燃料電池用ガス供給拡散層４２ｅの平面図である。FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42e according to Modification 5. 変形例６に係る燃料電池用ガス供給拡散層４２ｆの平面図である。14 is a plan view of a fuel cell gas supply diffusion layer 42f according to Modification 6. FIG. 変形例７に係る燃料電池用ガス供給拡散層４２ｇの平面図である。14 is a plan view of a fuel cell gas supply diffusion layer 42g according to Modification 7. FIG. 変形例８に係る燃料電池用ガス供給拡散層４２ｈの平面図である。14 is a plan view of a fuel cell gas supply diffusion layer 42h according to Modification 8. FIG. 変形例９に係る燃料電池用ガス供給拡散層４２ｉの平面図である。FIG. 10 is a plan view of a fuel cell gas supply diffusion layer 42i according to Modification 9. 変形例１０に係る燃料電池用ガス供給拡散層４２ｊの平面図である。14 is a plan view of a fuel cell gas supply diffusion layer 42j according to Modification 10. FIG. 図１７の部分断面図である。It is a fragmentary sectional view of FIG. 変形例１１に係る燃料電池用セパレータ２３ｋの断面図である。14 is a cross-sectional view of a fuel cell separator 23k according to Modification 11. FIG. 従来の燃料電池セルスタック９２０を模式的に示す正面図である。It is a front view which shows the conventional fuel cell stack 920 typically. 従来の燃料電池セルスタック９２０におけるタイプＣＡの燃料電池用セパレータ９２１の平面図である。FIG. 9 is a plan view of a fuel cell separator 921 of type CA in a conventional fuel cell stack 920. 従来の燃料電池セルスタック９２０におけるタイプＣＡの燃料電池用セパレータ９２１の平面図である。FIG. 9 is a plan view of a fuel cell separator 921 of type CA in a conventional fuel cell stack 920. 図２１のＡ－Ａ線に沿った断面図である。FIG. 22 is a cross-sectional view taken along line AA in FIG. 21.
　以下、本発明の燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックを図に示す実施形態を用いて詳細に説明する。 Hereinafter, a fuel cell gas supply diffusion layer, a fuel cell separator, and a fuel cell stack according to the present invention will be described in detail with reference to embodiments shown in the drawings.
［実施形態］
　図１は、実施形態に係る燃料電池セルスタック２０を模式的に示す正面図である。図２は、実施形態に係る燃料電池セルスタック２０を模式的に示す側面図である。 [Embodiment]
FIG. 1 is a front view schematically showing a fuel cell stack 20 according to an embodiment. FIG. 2 is a side view schematically showing the fuel cell stack 20 according to the embodiment.
　[燃料電池セルスタック]
　実施形態に係る燃料電池セルスタック２０は、固体高分子形燃料電池（PEFC：Polymer Electrolyte Fuel Cell）である。燃料電池セルスタック２０は、複数の単セルを有する。燃料電池の単セルは、概念的には電解質膜（高分子膜）（触媒層を含めてもよい）とこれを挟むカソード側を構成する要素とアノード側を構成する要素とから構成される。ここでは、燃料電池セルスタック２０の各セルは、後述する膜電極接合体８１を挟んでカソード側を構成する要素とアノード側を構成する要素とを有する。各セルは、セパレータを挟んで複数スタックされ、燃料電池セルスタック２０を構成する。 [Fuel battery cell stack]
The fuel cell stack 20 according to the embodiment is a polymer electrolyte fuel cell (PEFC). The fuel cell stack 20 has a plurality of single cells. A single cell of a fuel cell is conceptually composed of an electrolyte membrane (polymer membrane) (which may include a catalyst layer), an element constituting the cathode side sandwiching the membrane, and an element constituting the anode side. Here, each cell of the fuel cell stack 20 has an element constituting the cathode side and an element constituting the anode side with a membrane electrode assembly 81 described later interposed therebetween. A plurality of cells are stacked with a separator in between to constitute a fuel cell stack 20.
　本発明の実施形態に係る燃料電池用セパレータは、各セル間を分ける金属板３０を備えるとともに、種々のバリエーションを持って構成される。燃料電池用セパレータ２１は、ガス遮蔽板としての金属板３０の一方の面にカソードガス供給拡散層Ｃが形成され、他方の面にアノードガス供給拡散層Ａが形成されている（タイプＣＡのセパレータ）。したがって本発明の実施形態に係るタイプＣＡのセパレータのカソードガス供給拡散層Ｃとアノードガス供給拡散層Ａとはそれぞれ別のセルに組み込まれる。なお、タイプＣＡのセパレータの詳細については後述する。燃料電池用セパレータ２２は、金属板３０の一方の面にアノードガス供給拡散層Ａが形成されている（タイプＡのセパレータ）。燃料電池用セパレータ２３は、金属板３０の一方の面にカソードガス供給拡散層Ｃが形成されている（タイプＣのセパレータ）。燃料電池用セパレータ２４は、金属板３０の一方の面にカソードガス供給拡散層Ｃが形成され、他方の面に冷却水供給拡散層Ｗが形成されている（タイプＣＷのセパレータ）。 The separator for a fuel cell according to the embodiment of the present invention includes a metal plate 30 that separates cells and is configured with various variations. The fuel cell separator 21 has a cathode gas supply diffusion layer C formed on one surface of a metal plate 30 as a gas shielding plate, and an anode gas supply diffusion layer A formed on the other surface (type CA separator). ). Therefore, the cathode gas supply diffusion layer C and the anode gas supply diffusion layer A of the type CA separator according to the embodiment of the present invention are incorporated in different cells. Details of the type CA separator will be described later. The fuel cell separator 22 has an anode gas supply diffusion layer A formed on one surface of a metal plate 30 (type A separator). In the fuel cell separator 23, a cathode gas supply diffusion layer C is formed on one surface of a metal plate 30 (type C separator). In the fuel cell separator 24, the cathode gas supply diffusion layer C is formed on one surface of the metal plate 30, and the cooling water supply diffusion layer W is formed on the other surface (type CW separator).
　各セルは、カソード側とアノード側が交互になるように配置されている。カソードガス供給拡散層Ｃとアノードガス供給拡散層Ａとは、膜電極接合体（ＭＥＡ）８１を挟んで対向して設けられている。実施形態においては、単セルが２つ配置される毎に冷却水を供給する冷却水供給拡散層Ｗが設けられている。なお、冷却水供給拡散層Ｗは、単セル１つ置きに設けられていてもよいし、３つ置き又はそれ以上置きに設けられていてもよい。冷却水供給拡散層Ｗには金属板３０（好ましくはタイプＡ又はタイプＣのセパレータにおける金属板３０）が対向するように、燃料電池用セパレータ２１～２４が組み合わされて積層されている。 Each cell is arranged so that the cathode side and the anode side alternate. The cathode gas supply diffusion layer C and the anode gas supply diffusion layer A are provided to face each other with a membrane electrode assembly (MEA) 81 interposed therebetween. In the embodiment, a cooling water supply diffusion layer W that supplies cooling water every time two single cells are arranged is provided. The cooling water supply diffusion layer W may be provided every other single cell, or every three or more. Fuel cell separators 21 to 24 are combined and laminated so that the cooling water supply diffusion layer W faces the metal plate 30 (preferably the metal plate 30 in the type A or type C separator).
　なお、本発明の燃料電池セルスタックは、図１及び図２には図示していないが、金属板３０の一方の面にアノードガス供給拡散層Ａが形成され、他方の面に冷却水供給拡散層Ｗが形成されたもの（タイプＡＷのセパレータ）を備えていてもよい。また、金属板３０の一方の面に冷却水供給拡散層Ｗが形成されたセパレータ（タイプＷのセパレータ）を備えていてもよい。また、金属板３０の両面に冷却水供給拡散層Ｗが形成されたセパレータを備えていてもよい。各燃料電池用セパレータの構成の詳細については後述する。 Although the fuel cell stack of the present invention is not shown in FIGS. 1 and 2, the anode gas supply diffusion layer A is formed on one surface of the metal plate 30, and the cooling water supply diffusion is formed on the other surface. It may be provided with a layer W formed (type AW separator). Further, a separator (type W separator) in which the cooling water supply diffusion layer W is formed on one surface of the metal plate 30 may be provided. Further, a separator in which the cooling water supply diffusion layer W is formed on both surfaces of the metal plate 30 may be provided. Details of the configuration of each fuel cell separator will be described later.
　積層されたセルの両端部には、集電板２７Ａ，２７Ｂが配設されている。さらに集電板２７Ａ、２７Ｂの外側には、絶縁シート２８Ａ，２８Ｂを介してエンドプレート７５，７６が配置されている。燃料電池用セパレータ２１～２４は、エンドプレート７５、７６によって両側から押圧されている。燃料電池セルスタック２０の両端に位置し、集電板２７Ａ，２７Ｂに接する燃料電池用セパレータについては、その金属板３０（耐食層）が外方を向くようにすることが好ましい。 Current collector plates 27A and 27B are disposed at both ends of the stacked cells. Further, end plates 75 and 76 are disposed outside the current collecting plates 27A and 27B via insulating sheets 28A and 28B. The fuel cell separators 21 to 24 are pressed from both sides by end plates 75 and 76. For the fuel cell separators located at both ends of the fuel cell stack 20 and in contact with the current collector plates 27A and 27B, the metal plate 30 (corrosion resistant layer) is preferably directed outward.
　図１及び図２においては、燃料電池用セパレータ２１～２４、膜電極接合体８１、集電板２７Ａ，２７Ｂ、絶縁シート２８Ａ，２８Ｂ、及び、エンドプレート７５，７６は、分かり易くするために、離間して描かれているが、これらは、図示された配列の順に、相互に密に接合されている。接合の方法は特に限定されない。例えば、エンドプレート７５，７６により各部材を両側から押圧することのみによって接合してもよいし、各部材の適宜の位置を接着剤により接着したうえでエンドプレート７５，７６により各部材を両側から押圧することにより接合してもよし、その他の方法により接合してもよい。各燃料電池用セパレータ２１～２４、膜電極接合体８１、集電板２７Ａ，２７Ｂ、絶縁シート２８Ａ，２８Ｂ等は、例えば厚さが百μｍ程度から十ｍｍ程度である。本明細書の各実施形態における各図は、厚さを誇張して描かれている。 1 and 2, the fuel cell separators 21 to 24, the membrane electrode assembly 81, the current collector plates 27A and 27B, the insulating sheets 28A and 28B, and the end plates 75 and 76 are shown for easy understanding. Although depicted spaced apart, they are intimately joined to each other in the order shown. The method for joining is not particularly limited. For example, the members may be joined only by pressing the members from both sides with the end plates 75, 76, or the respective members may be joined from both sides by the end plates 75, 76 after bonding the appropriate positions of the members with an adhesive. It may be joined by pressing, or may be joined by other methods. Each of the fuel cell separators 21 to 24, the membrane electrode assembly 81, the current collecting plates 27A and 27B, the insulating sheets 28A and 28B, and the like have a thickness of about 100 μm to about 10 mm, for example. Each figure in each embodiment of the present specification is drawn with exaggerated thickness.
　アノード側のエンドプレート７５の一端部にはアノードガス供給口７１Ａ、カソードガス排出口７２Ｂ及び冷却水排出口７３Ｂがそれぞれ設けられている。他方、カソード側のエンドプレート７６の一端部（エンドプレート７５の上記一端部とは反対側）には、アノードガス排出口７１Ｂ、カソードガス供給口７２Ａ及び冷却水供給口７３Ａ（図２ではこれらがまとめて破線で示されている）が設けられている。これらの各供給口、各排出口にはそれぞれ対応する流体の供給管、排出管が接続されることになる。 An anode gas supply port 71A, a cathode gas discharge port 72B, and a cooling water discharge port 73B are provided at one end of the anode side end plate 75, respectively. On the other hand, an anode gas discharge port 71B, a cathode gas supply port 72A, and a cooling water supply port 73A (in FIG. 2, these are the ends of the cathode side end plate 76 (the side opposite to the one end of the end plate 75)). (Shown collectively in broken lines). Corresponding fluid supply pipes and discharge pipes are connected to the supply ports and the discharge ports, respectively.
　各燃料電池用セパレータ２１～２４には、それぞれ、アノードガス供給口７１Ａに連通するアノードガス流入口６１Ａ、カソードガス排出口７２Ｂに連通するカソードガス（及び生成水）流出口６２Ｂ、及び、冷却水排出口７３Ｂに連通する冷却水流出口６３Ｂが設けられている。また、各燃料電池用セパレータ２１～２４には、それぞれ、アノードガス排出口７１Ｂに連通するアノードガス流出口６１Ｂ、カソードガス供給口７２Ａに連通するカソードガス流入口６２Ａ、及び、冷却水供給口７３Ａに連通する冷却水流入口６３Ａが設けられている。 Each of the fuel cell separators 21 to 24 has an anode gas inlet 61A communicating with the anode gas supply port 71A, a cathode gas (and product water) outlet 62B communicating with the cathode gas outlet 72B, and cooling water. A cooling water outlet 63B communicating with the discharge port 73B is provided. Each of the fuel cell separators 21 to 24 has an anode gas outlet 61B communicating with the anode gas discharge port 71B, a cathode gas inlet 62A communicating with the cathode gas supply port 72A, and a cooling water supply port 73A. A cooling water inlet 63 </ b> A communicating with the cooling water is provided.
　アノードガス供給口７１Ａ、カソードガス供給口７２Ａ及び冷却水供給口７３Ａを通じてカソードガス、アノードガス及び冷却水が供給される。実施形態においては、アノードガスとして水素ガスを使用し、カソードガスとして空気を用いた場合を例示する。 The cathode gas, the anode gas, and the cooling water are supplied through the anode gas supply port 71A, the cathode gas supply port 72A, and the cooling water supply port 73A. In the embodiment, a case where hydrogen gas is used as the anode gas and air is used as the cathode gas is illustrated.
　[膜電極接合体]
　次に、膜電極接合体８１について説明する。
　図３は、膜電極接合体（ＭＥＡ）８１を説明するために示す図である。図３（ａ）は膜電極接合体８１の平面図であり、図３（ｂ）は膜電極接合体８１の正面図であり、図３（ｃ）は膜電極接合体の側面図である。 [Membrane electrode assembly]
Next, the membrane electrode assembly 81 will be described.
FIG. 3 is a view for explaining a membrane electrode assembly (MEA) 81. 3A is a plan view of the membrane electrode assembly 81, FIG. 3B is a front view of the membrane electrode assembly 81, and FIG. 3C is a side view of the membrane electrode assembly.
　膜電極接合体８１は、図３に示すように、電解質膜（PEM）８２と、電解質膜８２の両面にそれぞれ配置された触媒層（CL）８５と、各触媒層８５の外側の面に配置されたマイクロポーラスレイヤ（MPL）８３とを有する。実施形態においては、電解質膜８２とその両側に配置された触媒層８５から構成されるものを触媒コート電解質膜（Catalyst Coated Membrame:CCM）という。マイクロポーラスレイヤ８３は多孔質体層４０よりも微細な径の気孔（細孔）を有する。なお、マイクロポーラスレイヤ８３は、省略することもできる。 As shown in FIG. 3, the membrane electrode assembly 81 is arranged on an electrolyte membrane (PEM) 82, catalyst layers (CL) 85 arranged on both surfaces of the electrolyte membrane 82, and on the outer surface of each catalyst layer 85. The microporous layer (MPL) 83 is provided. In the embodiment, a structure composed of the electrolyte membrane 82 and the catalyst layers 85 disposed on both sides thereof is referred to as a catalyst coated electrolyte membrane (Catalyst Coated Membrame: CCM). The microporous layer 83 has pores (pores) with a diameter smaller than that of the porous body layer 40. The microporous layer 83 can be omitted.
［燃料電池用セパレータ、燃料電池用ガス供給拡散層］
　次に、燃料電池用セパレータ２１～２４及び燃料電池用ガス供給拡散層４２について説明する。
　図４は、タイプＣの燃料電池用セパレータ２３の金属板３０の側から見た平面図である。但し、図４においては、燃料電池用セパレータ２３の流路パターンを分かり易く表すために、金属板３０の図示は省略している。図５は、図４の断面図である。図５（ａ）は図４のＡ１－Ａ４断面図（但し、Ａ２－Ａ３部分は省略）であり、図５（ｂ）は図４のＡ２－Ａ３断面図である。図５においては、燃料電池用セパレータ２３と膜電極接合体８１との位置関係を示すために、膜電極接合体８１が接合された状態の燃料電池用セパレータ２３を示している。また、膜電極接合体８１の断面構造は省略している。図６は、燃料電池用ガスの流れを説明するために示す図である。図６（ａ）は図４のＢ部を拡大した平面図であり、図６（ｂ）は図６（ａ）のＣ－Ｃ線に沿った断面図である。 [Separators for fuel cells, gas supply diffusion layers for fuel cells]
Next, the fuel cell separators 21 to 24 and the fuel cell gas supply diffusion layer 42 will be described.
FIG. 4 is a plan view of the type C fuel cell separator 23 as viewed from the metal plate 30 side. However, in FIG. 4, the illustration of the metal plate 30 is omitted for easy understanding of the flow path pattern of the fuel cell separator 23. FIG. 5 is a cross-sectional view of FIG. 5A is a cross-sectional view along A1-A4 in FIG. 4 (however, the A2-A3 portion is omitted), and FIG. 5B is a cross-sectional view along A2-A3 in FIG. In FIG. 5, in order to show the positional relationship between the fuel cell separator 23 and the membrane electrode assembly 81, the fuel cell separator 23 in a state where the membrane electrode assembly 81 is joined is shown. Further, the cross-sectional structure of the membrane electrode assembly 81 is omitted. FIG. 6 is a view for explaining the flow of the fuel cell gas. 6A is an enlarged plan view of a portion B in FIG. 4, and FIG. 6B is a cross-sectional view taken along the line CC in FIG. 6A.
　なお、燃料電池用セパレータ２３には符号５５で示す孤立穴が複数形成されているが、図４においては図を見易くするために、一部の孤立穴にのみ符号を付して他の孤立穴に符号を付すのを省略する。また、図４～図６においては、孤立穴を示す符号５５の後に（５５１）～（５５３）のカッコ付きの符号を示す場合があるが、カッコ内の符号は、各孤立穴の相対位置関係に関する説明の便宜上示しており、特定の位置にある孤立穴を示すものではない。また、図６においては、矢印でカソードガスの流れを示すが、太い矢印で流入側から流出側に向かうカソードガスの全体的な流れを示し、細い矢印で孤立穴５５からガス拡散部４３中に押し出されたカソードガスの流れ（伏流ガス流れ）を示す。 In the fuel cell separator 23, a plurality of isolated holes indicated by reference numeral 55 are formed. However, in order to make the drawing easier to see in FIG. A reference numeral is omitted. In FIGS. 4 to 6, there are cases where the reference numerals (551) to (553) in parentheses are shown after the reference numeral 55 indicating an isolated hole. The reference numerals in parentheses indicate the relative positional relationship of each isolated hole. It is shown for convenience of explanation, and does not indicate an isolated hole at a specific position. In FIG. 6, the flow of the cathode gas is indicated by an arrow. The thick arrow indicates the overall flow of the cathode gas from the inflow side to the outflow side. The thin arrow indicates that the cathode gas flows from the isolated hole 55 into the gas diffusion portion 43. The flow of the pushed cathode gas (downflow gas flow) is shown.
　燃料電池用セパレータ２３は、図４及び図５に示すように、金属板３０の一方の面に燃料電池用ガス供給拡散層４２が形成された構造を有する。図５中、金属板３０には、断面であることを示すハッチングを施している。金属板３０は、インコネル、ニッケル、金、銀及び白金のうち一以上からなる金属、又はオーステナイト系ステンレス鋼板への金属のめっきもしくはクラッド材であることが好ましい。これらの金属を用いることにより、耐食性を向上できる。 As shown in FIGS. 4 and 5, the fuel cell separator 23 has a structure in which a fuel cell gas supply diffusion layer 42 is formed on one surface of the metal plate 30. In FIG. 5, the metal plate 30 is hatched to indicate a cross section. The metal plate 30 is preferably a metal composed of one or more of Inconel, nickel, gold, silver and platinum, or a metal plating or clad material on an austenitic stainless steel plate. Corrosion resistance can be improved by using these metals.
　燃料電池用セパレータ２３においては、金属板３０の縦方向の一端部（図４の下部）に、図４の右、中央、左の順に、カソードガス流入口６２Ａと、冷却水流入口６３Ａと、アノードガス流出口６１Ｂとが設けられている。また、他端部（図４の上部）に、図４の左、中央、右の順に、カソードガス流出口６２Ｂと、冷却水流出口６３Ｂと、アノードガス流入口６１Ａとが設けられている。 In the fuel cell separator 23, a cathode gas inlet 62A, a cooling water inlet 63A, and an anode are arranged at one end (the lower part in FIG. 4) of the metal plate 30 in the order of right, center, and left in FIG. A gas outlet 61B is provided. Further, a cathode gas outlet 62B, a cooling water outlet 63B, and an anode gas inlet 61A are provided at the other end (upper part of FIG. 4) in the order of left, center, and right in FIG.
　各流入口６１Ａ，６２Ａ，６３Ａ、各流出口６１Ｂ，６２Ｂ，６３Ｂ、及び、燃料電池用ガス供給拡散層４２の形成領域のそれぞれの周囲は、電子導電性又は非電子導電性の緻密枠３２によって囲まれている。緻密枠３２はアノードガス、カソードガス及び冷却水の漏洩を防ぐ。緻密枠３２の外面には、各流入口６１Ａ，６２Ａ，６３Ａ、各流出口６１Ｂ，６２Ｂ，６３Ｂ、及び、燃料電池用ガス供給拡散層４２の形成領域を囲むように、緻密枠３２に沿って溝３３Ａが形成されている（図４には不図示。）。この溝３３Ａ内にガスケット（パッキン、Ｏリングなどのシール材）３３が配置されている。 Each of the inlets 61A, 62A, 63A, each of the outlets 61B, 62B, 63B, and the periphery of the formation region of the fuel cell gas supply diffusion layer 42 is surrounded by an electron conductive or non-electron conductive dense frame 32. being surrounded. The dense frame 32 prevents leakage of anode gas, cathode gas and cooling water. On the outer surface of the dense frame 32, along the dense frame 32, the respective inlets 61 </ b> A, 62 </ b> A, 63 </ b> A, the outlets 61 </ b> B, 62 </ b> B, 63 </ b> B, and the fuel cell gas supply diffusion layer 42 are formed. A groove 33A is formed (not shown in FIG. 4). A gasket (a sealing material such as a packing and an O-ring) 33 is disposed in the groove 33A.
　金属板３０の両面には、上記の各流入口６１Ａ，６２Ａ，６３Ａ、及び、各流出口６１Ｂ，６２Ｂ，６３Ｂが設けられている部分を除いて、その全面に電子導電性を有する耐食層（図５においては図示せず）が形成されている。各流入口６１Ａ，６２Ａ，６３Ａ、及び、各流出口６１Ｂ，６２Ｂ，６３Ｂの内周面に耐食層が形成されていてもよい。金属板３０の側面及び端面に耐食層が形成されていてもよい。耐食層は、好ましくは緻密枠３２と同じ組成の緻密層であり、金属板３０の腐食を抑制する作用を有する。燃料電池用セパレータを組み合わせて図１あるいは図２に示すような燃料電池セルスタックを構成する段階で、ガスケット３３は接合される他の燃料電池用セパレータ、膜電極接合体８１又は集電板２７Ａ，２７Ｂと密着して流体の漏洩を抑制する。 On both surfaces of the metal plate 30, except for the portions where the respective inlets 61 A, 62 A, 63 A and the respective outlets 61 B, 62 B, 63 B are provided, the entire surface of the metal plate 30 has a corrosion-resistant layer having electronic conductivity ( (Not shown in FIG. 5). Corrosion-resistant layers may be formed on the inner peripheral surfaces of the inflow ports 61A, 62A, and 63A and the outflow ports 61B, 62B, and 63B. Corrosion-resistant layers may be formed on the side surfaces and end surfaces of the metal plate 30. The corrosion-resistant layer is preferably a dense layer having the same composition as the dense frame 32 and has an action of suppressing corrosion of the metal plate 30. At the stage of combining the fuel cell separator to form a fuel cell stack as shown in FIG. 1 or FIG. 2, the gasket 33 is joined to another fuel cell separator, membrane electrode assembly 81 or current collector plate 27A, Close contact with 27B to suppress fluid leakage.
　燃料電池用セパレータ２３は、タイプＣの燃料電池用セパレータであって、図４及び図５に示すように、基板としての長方形の金属板３０の一方の面における中央部に、上流側から下流側に向かってカソードガス（燃料電池用ガス）が流れてカソードガスを供給・拡散する燃料電池用ガス供給拡散層４２が形成されている。燃料電池用ガス供給拡散層４２は、使用時に上流側から下流側に向かって燃料電池用ガスが流れる燃料電池用ガス供給拡散層であって、燃料電池用ガスを透過、拡散し、導電性を有する多孔質体層４０を備える。多孔質体層４０は、多孔質体からなるガス拡散部４３と、多孔質体層４０の一方の面に分散して配置された複数の孤立穴５５とを有する。孤立穴５５の各々は、互いに孤立して多孔質体層４０に形成され、開口部を除く周囲がガス拡散部４３に囲まれ、多孔質体の底を有する凹部からなる。また、多孔質体層４０は、一方の面の流入側の隅部に位置するガス流入側溝５１と一方の面の流出側の隅部に位置するガス流出側溝５２とを有する（図４参照）。なお、多孔質体層４０は、必要に応じて、後述（変形例７）のガス圧均等化用溝５６、及び後述（変形例９）のバイパス用溝５９を有していてもよい。 The fuel cell separator 23 is a type C fuel cell separator, as shown in FIGS. 4 and 5, in the center of one surface of a rectangular metal plate 30 as a substrate, from the upstream side to the downstream side. A fuel cell gas supply diffusion layer 42 is formed in which cathode gas (fuel cell gas) flows toward and supplies and diffuses the cathode gas. The fuel cell gas supply diffusion layer 42 is a fuel cell gas supply diffusion layer through which the fuel cell gas flows from the upstream side to the downstream side when in use, and transmits and diffuses the fuel cell gas to provide conductivity. The porous body layer 40 is provided. The porous body layer 40 includes a gas diffusion portion 43 made of a porous body, and a plurality of isolated holes 55 that are dispersed and arranged on one surface of the porous body layer 40. Each of the isolated holes 55 is formed in the porous body layer 40 so as to be isolated from each other, and the periphery excluding the opening is surrounded by the gas diffusion portion 43 and includes a recess having the bottom of the porous body. Further, the porous body layer 40 has a gas inflow side groove 51 located at the corner on the inflow side of one surface and a gas outflow side groove 52 located at the corner on the outflow side of one surface (see FIG. 4). . The porous body layer 40 may have a gas pressure equalizing groove 56 described later (Modification 7) and a bypass groove 59 described later (Modification 9) as necessary.
　以降、上流側から下流側に向かう流れ方向（燃料電池用ガスの流入口が設けられている側の辺から燃料電池用ガスの流出口が設けられている辺に向かう方向，図４では符号Ｙの矢印の方向）をＹ方向とし、平面的にＹ方向に直交する幅方向（図４では符号Ｘの矢印の方向）をＸ方向として説明する。 Hereinafter, the flow direction from the upstream side to the downstream side (the direction from the side on the side where the fuel cell gas inlet is provided to the side where the fuel cell gas outlet is provided, Y in FIG. In the following description, the Y direction is defined as the Y direction, and the width direction (the direction of the arrow X in FIG. 4) orthogonal to the Y direction in the plan view is defined as the X direction.
　ガス流入側溝５１は、平面的に見て、多孔質体層４０の流入側の隅部において幅方向一杯に延びた細い矩形状の溝部分（段差部分）を有する。また、ガス流入側溝５１は、孤立穴５５に対応するように矩形状の溝部分（段差部分）からＹ方向流出側に分岐する複数の分岐溝部分（分岐段差部分）を有していてもよい。例えば、図４には、矩形状の溝部分（段差部分）から円形の孤立穴５５を切り取った形状でＹ方向流出側に分岐する複数の分岐溝部分（分岐段差部分）が描かれている。ガス流入側溝５１は、所定の深さで形成されている。 The gas inflow side groove 51 has a thin rectangular groove part (step part) extending in the width direction at the corner on the inflow side of the porous body layer 40 in plan view. Further, the gas inflow side groove 51 may have a plurality of branch groove portions (branch step portions) branched from the rectangular groove portion (step portion) to the Y direction outflow side so as to correspond to the isolated hole 55. . For example, FIG. 4 illustrates a plurality of branch groove portions (branch step portions) that branch to the outflow side in the Y direction in a shape obtained by cutting a circular isolated hole 55 from a rectangular groove portion (step portion). The gas inflow side groove 51 is formed with a predetermined depth.
　ガス流出側溝５２は、平面的に見て、多孔質体層４０の流出側の隅部において幅方向一杯に延びた細い矩形状の溝部分（段差部分）を有する。また、ガス流出側溝５２は、孤立穴５５に対応するように矩形状の溝部分（段差部分）からＹ方向流入側に分岐する複数の分岐溝部分（分岐段差部分）を有していてもよい。例えば、図４には、矩形状の溝部分（段差部分）から円形の孤立穴５５を切り取った形状でＹ方向流入側に分岐する複数の分岐溝部分（分岐段差部分）が描かれている。ガス流出側溝５２は、ガス流入側溝５１と同じ深さで形成されている。 The gas outflow side groove 52 has a thin rectangular groove part (step part) extending in the width direction at the corner on the outflow side of the porous body layer 40 in plan view. Further, the gas outflow side groove 52 may have a plurality of branch groove portions (branch step portions) branched from the rectangular groove portion (step portion) to the Y direction inflow side so as to correspond to the isolated hole 55. . For example, FIG. 4 illustrates a plurality of branch groove portions (branch step portions) that branch to the Y-direction inflow side in a shape obtained by cutting a circular isolated hole 55 from a rectangular groove portion (step portion). The gas outflow side groove 52 is formed with the same depth as the gas inflow side groove 51.
　実施形態に係る燃料電池用ガス供給拡散層においては、孤立穴５５が、多孔質体層４０の一方の面の所望の範囲にわたって分散して配置されている。各孤立穴５５は、所定の規則性を備えた形状が好ましく、各孤立穴５５の重心位置が、所定の規則性を備えて多孔質体層４０の一方の面に配置されていることが好ましい。ここで、所望の範囲とは、多孔質体層４０の一方の面に形成された孤立穴のうち、外側の孤立穴の重心位置を結んだ閉曲線に囲まれる範囲（図４では符号Ｒで示す二点鎖線に囲まれる範囲)である。所望の範囲は、多孔質体層の一方の表面積の６０％以上をカバーしていればよく、好ましくは７０％以上、さらに好ましくは８０％以上カバーしていればよい。所望の範囲は、多孔質体層４０の一方の面の全面にわたって分散配置するようにしてもよい。また、孤立穴が分散して配置されているというのは、Ｘ方向及びＹ方向に等ピッチで並んで配置されている場合だけを意味するものではなく、所望の範囲においてそれほど偏ることなく点在して配置されていることを意味する。 In the fuel cell gas supply diffusion layer according to the embodiment, the isolated holes 55 are distributed over a desired range on one surface of the porous body layer 40. Each isolated hole 55 preferably has a shape with a predetermined regularity, and the center of gravity of each isolated hole 55 is preferably disposed on one surface of the porous body layer 40 with a predetermined regularity. . Here, the desired range is a range surrounded by a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40 (indicated by reference numeral R in FIG. 4). (A range surrounded by a two-dot chain line). The desired range only needs to cover 60% or more of one surface area of the porous body layer, preferably 70% or more, and more preferably 80% or more. The desired range may be distributed over the entire surface of one surface of the porous body layer 40. In addition, the fact that the isolated holes are arranged in a distributed manner does not only mean that the holes are arranged at equal pitches in the X direction and the Y direction. Means that it is arranged.
　孤立穴５５は、所望の範囲の面積（多孔質体層４０の一方の面に形成された孤立穴のうち、外側の孤立穴の重心位置を結んだ閉曲線に囲まれる範囲の平面的な投影範囲の面積）をＳ１とし、複数の孤立穴５５の合計面積（複数の孤立穴５５を構成する全ての孤立穴について、それぞれの孤立穴の平面的な投影面積を合計した面積）をＳ２としたとき、「０．９×Ｓ１≧Ｓ２≧０．１×Ｓ１」の関係を満たすように配置されていることが好ましい。 The isolated hole 55 has an area within a desired range (a planar projection range of a range surrounded by a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40. ) Is S1, and the total area of the plurality of isolated holes 55 (the total area of the planar projection areas of the isolated holes for all the isolated holes constituting the plurality of isolated holes 55) is S2. , It is preferably arranged so as to satisfy the relationship of “0.9 × S1 ≧ S2 ≧ 0.1 × S1”.
　また、各孤立穴５５は、全て同じ形状、大きさとしてもよいし、形状のみ同じにしてその大きさを変えてもよい。なお、少なくとも所望の範囲において、孤立穴５５は、規則性をもたせて配置されていることが好ましい。 Further, all the isolated holes 55 may have the same shape and size, or the shape may be changed by changing only the shape. Note that it is preferable that the isolated holes 55 are arranged with regularity at least in a desired range.
　また孤立穴５５の底の形状は、膜電極接合体８１あるいは電解質膜（PEM）８２に対し平行に平坦でも、場所によってその深さが異なるようにしてもよい。 Further, the shape of the bottom of the isolated hole 55 may be flat in parallel to the membrane electrode assembly 81 or the electrolyte membrane (PEM) 82, or the depth thereof may be different depending on the location.
　したがって、実施形態に係る燃料電池用ガス供給拡散層４２は、複数の孤立穴５５が多孔質体層４０の一方の面に配置されていることから、燃料電池用ガスが孤立穴５５を流れる際にガス拡散部４３を伏流するよりも移動抵抗が小さくスムーズに流れるため、膜電極接合体８１に対して従来よりも多量の燃料電池用ガスを供給できる。 Therefore, in the fuel cell gas supply diffusion layer 42 according to the embodiment, since the plurality of isolated holes 55 are arranged on one surface of the porous body layer 40, the fuel cell gas flows through the isolated holes 55. In addition, since the movement resistance is smaller than that flowing down through the gas diffusion part 43 and flows smoothly, a larger amount of fuel cell gas can be supplied to the membrane electrode assembly 81 than in the prior art.
　また、実施形態に係る燃料電池用ガス供給拡散層４２は、複数の孤立穴５５が多孔質体層４０の一方の面に形成されていることから、多孔質体層４０の他方の面に配設される膜電極接合体８１に対する燃料電池用ガスの供給は必ず多孔質体（ガス拡散部４３）を介して行われるため、複数のガス流路が多孔質体層４０の一方の面から他方の面にかけて形成されている場合よりも燃料電池用ガスを膜電極接合体に対して均一に供給できる。 In addition, the fuel cell gas supply diffusion layer 42 according to the embodiment has a plurality of isolated holes 55 formed on one surface of the porous body layer 40, and thus is disposed on the other surface of the porous body layer 40. Since the fuel cell gas is always supplied to the membrane electrode assembly 81 provided through the porous body (gas diffusion portion 43), a plurality of gas flow paths are formed from one surface of the porous body layer 40 to the other. The fuel cell gas can be supplied more uniformly to the membrane electrode assembly than in the case of being formed over the surface.
　また、孤立穴の周囲が多孔質体（ガス拡散部４３）で囲まれていることから、下流側の孤立穴には必ず多孔質体（ガス拡散部４３）を通って進行するため、多孔質体層４０にガス流路が流入側から流出側まで繋がるように形成されている場合よりも、燃料電池用ガスを多孔質体層４０全体にわたって均一に拡散させることができる。 Further, since the periphery of the isolated hole is surrounded by the porous body (gas diffusion portion 43), the downstream isolated hole always proceeds through the porous body (gas diffusion portion 43), so that the porous body is porous. The fuel cell gas can be diffused more uniformly throughout the porous body layer 40 than when the gas flow path is formed in the body layer 40 so as to be connected from the inflow side to the outflow side.
　その結果、実施形態に係る燃料電池用ガス供給拡散層４２は、従来よりも多量の燃料電池用ガスを膜電極接合体８１に対して均一に供給できるようになることから、従来よりも燃料電池の発電効率を高くできる、燃料電池用ガス供給拡散層となる。 As a result, the fuel cell gas supply diffusion layer 42 according to the embodiment can uniformly supply a larger amount of fuel cell gas to the membrane electrode assembly 81 than in the prior art. Thus, the fuel cell gas supply diffusion layer can be improved.
　また、実施形態に係る燃料電池用ガス供給拡散層４２は、上記のような特徴を有することから、発電に使用されなかった燃料電池用ガス（この場合カソードガス（酸素ガス、窒素ガス））を、多孔質体（ガス拡散部４３）及び孤立穴５５を介して効率良く燃料電池用ガス供給拡散層４２外に排出できるようになるため、従来よりも燃料電池用ガスの移動抵抗が低く、ひいては、反応ガス濃度を高く保つことになり、従来よりも燃料電池の発電効率を高くできる、燃料電池用ガス供給拡散層となる。 Further, since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, the fuel cell gas (in this case, cathode gas (oxygen gas, nitrogen gas)) not used for power generation is used. In addition, since the gas can be efficiently discharged out of the fuel cell gas supply diffusion layer 42 through the porous body (gas diffusion portion 43) and the isolated hole 55, the movement resistance of the fuel cell gas is lower than that in the prior art. Therefore, the concentration of the reaction gas is kept high, and the fuel cell gas supply diffusion layer that can increase the power generation efficiency of the fuel cell as compared with the prior art is obtained.
　また、実施形態に係る燃料電池用ガス供給拡散層４２は、上記のような特徴を有することから、発電時に膜電極接合体８１で生成した水蒸気または凝集水を、多孔質体（ガス拡散部４３）及び孤立穴５５を介して効率良く燃料電池用ガス供給拡散層４２外に排出できるようになるため、従来よりも排水性に優れた燃料電池用ガス供給拡散層となる。 In addition, since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation is converted into a porous body (the gas diffusion portion 43). ) And the isolated hole 55, the fuel cell gas supply diffusion layer 42 can be efficiently discharged out of the fuel cell gas supply diffusion layer 42. Therefore, the fuel cell gas supply diffusion layer has better drainage than the conventional one.
　各孤立穴５５は、幅が変化している形状であってもよく、例えば平面的に見て円形、楕円、菱形、三角形などとしてもよい。各孤立穴５５は、ガス流入側溝５１及びガス流出側溝５２と同じ深さ、且つ一定の深さで形成してもよい。各孤立穴５５は、内表面に多孔質体からなるガス拡散部４３が露出している。 Each isolated hole 55 may have a shape whose width changes, and may be, for example, a circle, an ellipse, a rhombus, a triangle, or the like when viewed in a plan view. Each isolated hole 55 may be formed at the same depth as the gas inflow side groove 51 and the gas outflow side groove 52 and a constant depth. In each isolated hole 55, the gas diffusion portion 43 made of a porous material is exposed on the inner surface.
　このように、複数の孤立穴５５が円形、楕円、菱形、三角形などのように幅が変化するような構成をとれば、燃料電池用ガスを二次元的に広げて供給することも可能となる。 In this way, if the plurality of isolated holes 55 have a configuration in which the width changes such as a circle, an ellipse, a rhombus, and a triangle, the fuel cell gas can be two-dimensionally expanded and supplied. .
　孤立穴は、複数の孤立穴のうちの一の孤立穴と一の孤立穴の下流側に近接する孤立穴との位置関係に規則性をもたせて配置されていることが好ましい。孤立穴５５は、図４に示すように、複数の孤立穴５５のうちの一の孤立穴５５１から下流側に位置する孤立穴のうち、一の孤立穴５５１からＸ方向に沿った距離が最も短い孤立穴（すなわち孤立穴５５１の重心位置と近接する孤立穴の重心位置とを結ぶベクトルのＸ方向成分の絶対値が最も小さい（当該絶対値がゼロの場合ももちろん含む）孤立穴を第１近接孤立穴５５２とし、一の孤立穴５５１からＸ方向に沿った距離が二番目に短い孤立穴（すなわち孤立穴５５１の重心位置と近接する孤立穴の重心位置とを結ぶベクトルのＸ方向成分の絶対値が二番目に小さい孤立穴）を第２近接孤立穴５５３としたとき、一の孤立穴５５１と第１近接孤立穴５５２との間の距離であって、一の孤立穴５５１の開口部と第１近接孤立穴５５２の開口部との間の最短距離である第１間隔Ｌ１と、一の孤立穴５５１と第２近接孤立穴５５３との間の距離であって、一の孤立穴５５１の開口部と第２近接孤立穴５５３の開口部との間の最短距離である第２間隔Ｌ２とは、図４に示すように、「Ｌ２≦Ｌ１」の関係を満たすようにするとよい。すなわち、一の孤立穴５５１には、Ｙ方向に並ぶ（Ｘ方向に沿った距離が最も短い）第１近接孤立穴５５２と隣の列（両隣の列）に位置する第２近接孤立穴５５３とが近接しているが、燃料電池用ガスが一の孤立穴５５１から第２近接孤立穴５５３に移動する際にガス拡散部４３を通過する距離は、一の孤立穴５５１から第１近接孤立穴５５２に移動する際にガス拡散部４３を通過する距離よりも短くなるようにする。このようにすると、一の孤立穴５５１から押し出された燃料電池用ガスは、第１近接孤立穴５５２よりも第２近接孤立穴５５３に向かって流れやすくなる。このため、一の孤立穴５５１から押し出された燃料電池用ガスが、第１近接孤立穴５５２に向かうよりも第２近接孤立穴５５３に多く向かうことでより広く拡散するようになる。よって、燃料電池用ガスを多孔質体層４０全体にわたって均一に拡散させることができる。 The isolated holes are preferably arranged with regularity in the positional relationship between one isolated hole of the plurality of isolated holes and the isolated hole adjacent to the downstream side of the one isolated hole. As shown in FIG. 4, the isolated hole 55 has the longest distance along the X direction from one isolated hole 551 among the isolated holes located downstream from one isolated hole 551 among the plurality of isolated holes 55. The first isolated hole having the shortest isolated hole (that is, the absolute value of the X direction component of the vector connecting the centroid position of the isolated hole 551 and the centroid position of the adjacent isolated hole is the smallest (including the case where the absolute value is zero). The isolated isolated hole 552 is an isolated hole whose distance along the X direction from the one isolated hole 551 is the second shortest (that is, the X direction component of the vector connecting the gravity center position of the isolated hole 551 and the gravity center position of the adjacent isolated hole) (The isolated hole having the second smallest absolute value) is the second adjacent isolated hole 553, which is the distance between one isolated hole 551 and the first adjacent isolated hole 552, and is the opening of the one isolated hole 551. And the opening of the first adjacent isolated hole 552 The first distance L1 that is the shortest distance between the two and the distance between one isolated hole 551 and the second adjacent isolated hole 553, that is, the opening of the one isolated hole 551 and the second adjacent isolated hole 553. 4, it is preferable to satisfy the relationship of “L2 ≦ L1” as shown in Fig. 4. That is, in one isolated hole 551, the second interval L2 is in the Y direction. The first adjacent isolated holes 552 that are lined up (the distance along the X direction is the shortest) and the second adjacent isolated holes 553 located in the adjacent rows (both adjacent rows) are close to each other. The distance that passes through the gas diffusion portion 43 when moving from one isolated hole 551 to the second adjacent isolated hole 553 passes through the gas diffusion portion 43 when moving from one isolated hole 551 to the first adjacent isolated hole 552. It should be shorter than the distance. The extruded fuel cell gas is more likely to flow toward the second adjacent isolated hole 553 than to the first adjacent isolated hole 552. Therefore, the fuel cell gas extruded from the one isolated hole 551 is the first The gas diffuses more widely by moving toward the second adjacent isolated hole 553 rather than toward the adjacent isolated hole 552. Accordingly, the fuel cell gas can be uniformly diffused throughout the porous body layer 40.
　また、第１間隔Ｌ１と第２間隔Ｌ２とは、図４に示すように、さらに「Ｌ１＜２×Ｌ２」の関係を満たすようにしてもよい。すなわち、一の孤立穴５５１と第２近接孤立穴５５３との間隔が第２近接孤立穴５５３と第１近接孤立穴５５２との間隔と同じであるため、燃料電池用ガスが一の孤立穴５５１から直接第１近接孤立穴５５２に移動する際にガス拡散部４３を通過する距離は、一の孤立穴５５１から第２近接孤立穴５５３を経由して第１近接孤立穴５５２に移動する際にガス拡散部４３を通過する距離よりも短くする。このようにすると、燃料電池用ガスが一の孤立穴５５１から直接第１近接孤立穴５５２に移動する際にガス拡散部４３を通過する距離（第１間隔Ｌ１）は、料電池用ガスが一の孤立穴５５１から第２近接孤立穴５５３を経由して第１近接孤立穴５５２に移動する際にガス拡散部４３を通過する距離（２×第２間隔Ｌ２）より短くなる。このため、一の孤立穴５５１から直接第１近接孤立穴５５２に向かう燃料電池用ガスの流れが極端に少なくなることはなく、多孔質体層４０全体にわたってバランス良く燃料電池用ガスを拡散させることができる。 Further, as shown in FIG. 4, the first interval L1 and the second interval L2 may further satisfy the relationship “L1 <2 × L2”. That is, since the distance between one isolated hole 551 and the second adjacent isolated hole 553 is the same as the distance between the second adjacent isolated hole 553 and the first adjacent isolated hole 552, the fuel cell gas is one isolated hole 551. When moving from the first isolated hole 551 to the first adjacent isolated hole 552 via the second adjacent isolated hole 553, the distance passing through the gas diffusion portion 43 when moving directly from the first adjacent isolated hole 552 to the first adjacent isolated hole 552 is as follows. The distance is shorter than the distance passing through the gas diffusion part 43. In this way, when the fuel cell gas moves directly from the one isolated hole 551 to the first adjacent isolated hole 552, the distance (first interval L1) that passes through the gas diffusion portion 43 is equal to the fuel cell gas. When moving from the isolated hole 551 to the first adjacent isolated hole 552 via the second adjacent isolated hole 553, the distance through the gas diffusion portion 43 (2 × second interval L2) is shorter. For this reason, the flow of the fuel cell gas from one isolated hole 551 directly toward the first adjacent isolated hole 552 does not extremely decrease, and the fuel cell gas is diffused in a well-balanced manner throughout the porous body layer 40. Can do.
　なお、「Ｌ２≦Ｌ１」の関係、及び、「Ｌ１＜２×Ｌ２」の関係を満たす場合には、孤立穴間のＸ方向のピッチ及びＹ方向のピッチの値については、これらの、「Ｌ２≦Ｌ１」の関係、及び、「Ｌ１＜２×Ｌ２」の関係を満たす範囲で、適宜設定すればよい。 When the relationship of “L2 ≦ L1” and the relationship of “L1 <2 × L2” are satisfied, the values of the pitch in the X direction and the pitch in the Y direction between the isolated holes are “L2 ≦ L1 ”and a range satisfying the relationship“ L1 <2 × L2 ”may be set as appropriate.
　実施形態に係る燃料電池用ガス供給拡散層においては、所望の範囲の面積（多孔質体層４０の一方の面に形成された孤立穴のうち、外側の孤立穴の重心位置を結んだ閉曲線に囲まれる範囲の平面的な投影範囲の面積）Ｓ１と複数の孤立穴の合計面積Ｓ２とが「０．９×Ｓ１≧Ｓ２≧０．１×Ｓ１」の関係を満たすように配置されていることが好ましい理由は以下の通りである。すなわち、上記のＳ２が上記のＳ１の１０％以上である場合には、燃料電池用ガスが所望の範囲を流れる際の移動抵抗を十分に小さくできるため、膜電極接合体８１に対して従来よりも多量の燃料電池用ガスを供給できるからである。また、Ｓ２がＳ１の９０％以下である場合には、燃料電池用ガスが所望の範囲内を拡散しながら伏流する領域を最低限確保できるため、燃料電池用ガスを所望の範囲内において均一に拡散させやすくできるからである。なお、より多量の燃料電池用ガスを供給するという観点からは、多孔質体層４０の面積Ｓ１と複数の孤立穴の合計面積Ｓ２とは、「Ｓ２≧０．２×Ｓ１」の関係を満たすことがより好ましく、「Ｓ２≧０．３×Ｓ１」の関係を満たすことがより一層好ましい。また、所望の範囲内において拡散させるという観点からは、「０．８×Ｓ１≧Ｓ２」の関係を満たすことがより好ましく、「０．７×Ｓ１≧Ｓ２」の関係を満たすことがより一層好ましい。 In the fuel cell gas supply diffusion layer according to the embodiment, a desired range of area (a closed curve connecting the center of gravity positions of the outer isolated holes among the isolated holes formed on one surface of the porous body layer 40). The area of the planar projection range of the enclosed range) S1 and the total area S2 of the plurality of isolated holes should be arranged so as to satisfy the relationship of “0.9 × S1 ≧ S2 ≧ 0.1 × S1”. The reason why is preferable is as follows. That is, when the above S2 is 10% or more of the above S1, the movement resistance when the fuel cell gas flows in a desired range can be made sufficiently small. This is because a large amount of fuel cell gas can be supplied. In addition, when S2 is 90% or less of S1, a region where the fuel cell gas diffuses in the desired range and flows downward can be secured at a minimum, so that the fuel cell gas is uniformly distributed within the desired range. This is because it can be easily diffused. From the viewpoint of supplying a larger amount of fuel cell gas, the area S1 of the porous body layer 40 and the total area S2 of the plurality of isolated holes satisfy the relationship of “S2 ≧ 0.2 × S1”. It is more preferable that the relationship of “S2 ≧ 0.3 × S1” is satisfied. Further, from the viewpoint of diffusing within a desired range, it is more preferable to satisfy the relationship of “0.8 × S1 ≧ S2”, and it is even more preferable to satisfy the relationship of “0.7 × S1 ≧ S2”. .
　ガス拡散部４３は、導電性を有し、細かな空隙が形成されている多孔質体からなる。ガス拡散部４３は、平面的に見て略矩形状をしている。ガス拡散部４３は、気体や液体をこの空隙を通して伏流させるのに適した気孔率で形成されている。詳細は後述する。 The gas diffusion part 43 is made of a porous body having conductivity and having fine voids formed therein. The gas diffusion portion 43 has a substantially rectangular shape when seen in a plan view. The gas diffusion portion 43 is formed with a porosity suitable for allowing a gas or liquid to flow down through this gap. Details will be described later.
　なお、本明細書において、「伏流」とは、ガス流入側溝５１、各孤立穴５５、後述のガス圧均等化用溝５６（変形例７）、及び後述のバイパス用溝５９（変形例９）等からガス拡散部４３中に押し出されたカソードガス（伏流ガス）の流れをいう。
　また、本明細書において、「ガスの流入側から流出側に向かって」とは、「およそガスの流れるＹ方向に沿って」という意味であり、「ガスの流入側から流出側に向かう」方向は、多孔質体層４０全体としてみた場合の多孔質体層４０内のガスのＹ方向に沿った流れの方向である。これは、実施形態に係る燃料電池用ガス供給拡散層４２のように、カソードガス流入口６２Ａとカソードガス流出口６２Ｂが金属板３０の対角線上の位置に配設されている場合に、ガス流路は上記の対角線に沿って形成されている必要はなく、実施形態のように、「ガスの流入側から流出側に向かう」方向は、「多孔質体層４０全体としてみた場合の多孔質体層４０内のガスの流れの方向が、図４の紙面の下から上のＹ方向に向かうような場合は」、図４のように、図４の紙面の下から上のＹ方向に沿って孤立穴５５は整列されていればよいし、また、それ以外の方向に沿って整列されていてもよい。 In the present specification, “downflow” refers to the gas inflow side groove 51, each isolated hole 55, a gas pressure equalizing groove 56 described later (Modification 7), and a bypass groove 59 described below (Modification 9). The flow of cathode gas (downflow gas) pushed into the gas diffusion part 43 from the above.
Further, in this specification, “from the gas inflow side to the outflow side” means “approximately along the Y direction in which the gas flows”, and the direction “from the gas inflow side to the outflow side”. Is the direction of flow of the gas in the porous body layer 40 along the Y direction when viewed as the entire porous body layer 40. This is because when the cathode gas inlet 62A and the cathode gas outlet 62B are arranged at diagonal positions on the metal plate 30 as in the fuel cell gas supply diffusion layer 42 according to the embodiment. The path does not have to be formed along the above diagonal line, and the direction “from the gas inflow side to the outflow side” as in the embodiment is “a porous body when viewed as the entire porous body layer 40” When the direction of the gas flow in the layer 40 is from the bottom to the top in the Y direction in FIG. 4 ”, the bottom direction from the bottom to the top in FIG. The isolated holes 55 may be aligned, and may be aligned along other directions.
　さらに、燃料電池用セパレータ２３に関して詳しく説明する。カソードガスとしての空気（酸素ガス及び窒素ガス）は、多孔質体層４０（ガス拡散部４３）内を拡散する。多孔質体層４０は、導電材（好ましくは炭素系導電材）と高分子樹脂の混合物を含む。高分子樹脂に炭素系導電材を混合することにより、高分子樹脂に高い導電性を付与することができ、また高分子樹脂の結着性により炭素材の成型性を向上させることができる。多孔質体層４０の流体抵抗は、多孔質体層の気孔率と流体の流れる面の面積に依存する。気孔率が大きくなれば流体抵抗は小さくなる。流体が流れる面積が大きくなれば流体抵抗は小さくなる。およその目安としては、（カソードガス用の）燃料電池用ガス供給拡散層４２においては、多孔質体層４０の気孔率は、５０～８５％程度である。なお、（アノードガス用の）燃料電池用ガス供給拡散層４１においては、多孔質体層４０の気孔率は、３０～８５％程度である。 Further, the fuel cell separator 23 will be described in detail. Air (oxygen gas and nitrogen gas) as the cathode gas diffuses in the porous body layer 40 (gas diffusion portion 43). The porous body layer 40 includes a mixture of a conductive material (preferably a carbon-based conductive material) and a polymer resin. By mixing the carbon-based conductive material with the polymer resin, high conductivity can be imparted to the polymer resin, and the moldability of the carbon material can be improved by the binding property of the polymer resin. The fluid resistance of the porous body layer 40 depends on the porosity of the porous body layer and the area of the surface through which the fluid flows. As the porosity increases, the fluid resistance decreases. If the area through which the fluid flows increases, the fluid resistance decreases. As a rough guide, in the fuel cell gas supply diffusion layer 42 (for the cathode gas), the porosity of the porous body layer 40 is about 50 to 85%. In the fuel cell gas supply diffusion layer 41 (for anode gas), the porosity of the porous body layer 40 is about 30 to 85%.
　多孔質体層４０の気孔率が上記のように構成されていることから、ガス流路用溝５５の内表面を介して、孤立穴５５と多孔質体層４０との間のカソードガス、水蒸気、凝結水の流通が適切に行われるようになる結果、多量の燃料電池用ガスを膜電極接合体に対して均一に供給できるようになり、また、発電時に使用されなかったカソードガスや発電時に生成した水蒸気や凝結水を孤立穴外に効率よく排出することができるようになる。その結果、燃料電池用ガス供給拡散層４２においては、孤立穴５５は、孤立穴５５の内表面に金属、セラミックス、樹脂等からなるガス不透過層に微細なガス流通孔を多数開口したガス透過フィルターのようなものを形成する必要が無く、内表面に多孔質体からなるガス拡散部４３が露出するよう構成されている。 Since the porosity of the porous body layer 40 is configured as described above, the cathode gas and water vapor between the isolated hole 55 and the porous body layer 40 via the inner surface of the gas flow channel groove 55. As a result of the proper circulation of condensed water, a large amount of fuel cell gas can be supplied uniformly to the membrane electrode assembly. The generated water vapor and condensed water can be efficiently discharged out of the isolated hole. As a result, in the gas supply diffusion layer 42 for the fuel cell, the isolated hole 55 has a gas permeable structure in which a number of fine gas flow holes are opened in the gas impervious layer made of metal, ceramics, resin, or the like on the inner surface of the isolated hole 55. There is no need to form a filter, and the gas diffusion portion 43 made of a porous material is exposed on the inner surface.
　炭素系導電材の含有率を調整することにより、燃料電池用ガス供給拡散層４２の気孔率を調整することができ、ひいては、燃料電池用ガス供給拡散層４２の移動抵抗を調整することができる。特に炭素系導電材の含有率を高くすると移動抵抗が小さくなる（気孔率が大きくなる）。逆に、炭素系導電材の含有率を低くすると移動抵抗が大きくなる（気孔率が小さくなる）。耐食層及び緻密枠３２も炭素系導電材と高分子樹脂の混合物であり、炭素系導電材の適度な含有率により、導電性を確保しつつ緻密化したものであるのが好ましい。 By adjusting the content of the carbon-based conductive material, the porosity of the fuel cell gas supply diffusion layer 42 can be adjusted, and consequently the movement resistance of the fuel cell gas supply diffusion layer 42 can be adjusted. . In particular, when the content of the carbon-based conductive material is increased, the movement resistance is decreased (the porosity is increased). Conversely, when the content of the carbon-based conductive material is lowered, the movement resistance is increased (the porosity is decreased). The corrosion-resistant layer and the dense frame 32 are also a mixture of a carbon-based conductive material and a polymer resin, and are preferably densified while ensuring conductivity by an appropriate content of the carbon-based conductive material.
　炭素系導電材としては特に限定されないが、例えば黒鉛、カーボンブラック、ダイヤモンド被覆カーボンブラック、炭化ケイ素、炭化チタン、カーボン繊維、カーボンナノチューブ等を用いることができる。高分子樹脂としては、熱硬化性樹脂及び熱可塑性樹脂のいずれも用いることができる。高分子樹脂の例としては、フェノール樹脂、エポキシ樹脂、メラミン樹脂、ゴム系樹脂、フラン樹脂、フッ化ビニリデン樹脂等が挙げられる。 The carbon-based conductive material is not particularly limited. For example, graphite, carbon black, diamond-coated carbon black, silicon carbide, titanium carbide, carbon fiber, carbon nanotube, and the like can be used. As the polymer resin, any of a thermosetting resin and a thermoplastic resin can be used. Examples of the polymer resin include phenol resin, epoxy resin, melamine resin, rubber-based resin, furan resin, vinylidene fluoride resin, and the like.
　カソードガス流入口６２Ａと多孔質体層４０が形成されている領域との間には流入通路５７が形成されている（図４参照。）。カソードガス流出口６２Ｂと多孔質体層４０が形成されている領域との間には流出通路５８が形成されている。これらの流入通路５７及び流出通路５８は膜電極接合体８１又はそのフレーム８１Ａを支持するためのものである。したがって、カソードガスを円滑に流し、かつ膜電極接合体８１をサポートできる構造であればよい。例えば、気孔率のきわめて大きい多孔質体層でもよいし、多数の支柱を配列した構造でもよい。多孔質体層４０における流入通路５７と面する領域には金属板３０の幅方向に沿って細長い流入側溝５１が形成されている。また、多孔質体層４０における流出通路５８と面する領域にも金属板３０の幅方向に沿って細長い流出側溝５２が形成されている。但し、流入側溝５１及び流出側溝５２は、これらを省略することもできる。 An inflow passage 57 is formed between the cathode gas inlet 62A and the region where the porous body layer 40 is formed (see FIG. 4). An outflow passage 58 is formed between the cathode gas outlet 62B and the region where the porous body layer 40 is formed. These inflow passage 57 and outflow passage 58 are for supporting the membrane electrode assembly 81 or its frame 81A. Accordingly, any structure that can smoothly flow the cathode gas and can support the membrane electrode assembly 81 may be used. For example, it may be a porous body layer having a very high porosity or a structure in which a large number of support columns are arranged. An elongated inflow side groove 51 is formed along the width direction of the metal plate 30 in a region facing the inflow passage 57 in the porous body layer 40. An elongated outflow side groove 52 is also formed in the region facing the outflow passage 58 in the porous body layer 40 along the width direction of the metal plate 30. However, the inflow side groove 51 and the outflow side groove 52 can be omitted.
　多孔質体層４０、流入通路５７、及び流出通路５８は、図５に示すように、緻密枠３２と同じ高さ（厚さ）に形成されている。燃料電池用ガス供給拡散層４２における金属板３０に対向する側の面には、空隙からなる複数の孤立穴５５が設けられており、これら複数の孤立穴５５と金属板３０との隙間に複数のガス流路が形成されている。孤立穴５５は前述したような配置で複数形成されている。各孤立穴５５は、ガス拡散部４３を伏流して流入してきた燃料電池用ガスを、移動抵抗を減らして広げて再びガス拡散部４３に流出させることで、強制伏流により拡散させる。孤立穴５５の数及び構造は図示のものに限定されない。 The porous body layer 40, the inflow passage 57, and the outflow passage 58 are formed at the same height (thickness) as the dense frame 32, as shown in FIG. A plurality of isolated holes 55 formed of voids are provided on the surface of the fuel cell gas supply diffusion layer 42 facing the metal plate 30. A plurality of isolated holes 55 and a plurality of metal plates 30 are provided in the gaps between the plurality of isolated holes 55. The gas flow path is formed. A plurality of isolated holes 55 are formed in the arrangement as described above. Each isolated hole 55 diffuses the fuel cell gas that has flowed down through the gas diffusion portion 43 by reducing the movement resistance and flows out to the gas diffusion portion 43 again by forced downflow. The number and structure of the isolated holes 55 are not limited to those illustrated.
　実施形態に係る燃料電池用ガス供給拡散層４２は、これを輸送機器用の燃料電池に用いる場合には、輸送機器の種類・大きさにもよるが、多孔質体層４０の横幅は例えば３０ｍｍ～３００ｍｍ程度である。孤立穴５５の幅Ｗは例えば０．３ｍｍ～２ｍｍ程度である。多孔質体層４０の厚さは例えば１５０～４００μｍ程度であり、孤立穴５５の深さは例えば１００～３００μｍ程度であり、孤立穴の底と多孔質体層４０の他方の面との距離（天井厚）は例えば１００～３００μｍ程度である。実施形態に係る燃料電池用ガス供給拡散層４２を輸送機器以外の用途（例えば定置用）の燃料電池に用いる場合には、上記のサイズに限定されるものではなく、必要とされる性能などに応じて適宜のサイズのものを用いることができる。 When the fuel cell gas supply diffusion layer 42 according to the embodiment is used in a fuel cell for transportation equipment, the width of the porous body layer 40 is, for example, 30 mm, depending on the type and size of the transportation equipment. About 300 mm. The width W of the isolated hole 55 is, for example, about 0.3 mm to 2 mm. The thickness of the porous body layer 40 is, for example, about 150 to 400 μm, the depth of the isolated hole 55 is, for example, about 100 to 300 μm, and the distance between the bottom of the isolated hole and the other surface of the porous body layer 40 ( The ceiling thickness is, for example, about 100 to 300 μm. When the fuel cell gas supply diffusion layer 42 according to the embodiment is used for a fuel cell for an application other than transportation equipment (for example, for stationary use), the size is not limited to the above-described size, and the required performance, etc. Depending on the size, an appropriate size can be used.
　タイプＡの燃料電池用セパレータ２２における燃料電池用ガス供給拡散層４１も、基本的には燃料電池用ガス供給拡散層４２と同様の構成を有する。但し、燃料電池用ガス供給拡散層に供給するガスが水素ガスであることから、燃料電池用ガス供給拡散層４２よりも気孔率が低く、また、厚さが薄い（後述する図７（ｂ）参照。）。 The fuel cell gas supply diffusion layer 41 in the type A fuel cell separator 22 basically has the same configuration as the fuel cell gas supply diffusion layer 42. However, since the gas supplied to the fuel cell gas supply diffusion layer is hydrogen gas, the porosity is lower and the thickness is smaller than that of the fuel cell gas supply diffusion layer 42 (FIG. 7B described later). reference.).
　タイプＣＡの燃料電池用セパレータ２１においては、燃料電池用ガス供給拡散層として燃料電池用ガス供給拡散層４１及び燃料電池用ガス供給拡散層４２を用いる（後述する図７（ａ）参照。）。タイプＣＷの燃料電池用セパレータ２４は、タイプＣの燃料電池用セパレータ２３における燃料電池用ガス供給拡散層４２が形成されていない面に冷却水供給拡散層が形成されたものである（後述する図７（ｃ）参照。）。タイプＡＷの燃料電池用セパレータ２５は、タイプＡの燃料電池用セパレータ２２における燃料電池用ガス供給拡散層４１が形成されていない面に冷却水供給拡散層が形成されたものである（後述する図７（ｄ）参照。）。 In the fuel cell separator 21 of type CA, the fuel cell gas supply diffusion layer 41 and the fuel cell gas supply diffusion layer 42 are used as the fuel cell gas supply diffusion layer (see FIG. 7A described later). The type CW fuel cell separator 24 is obtained by forming a cooling water supply diffusion layer on the surface of the type C fuel cell separator 23 where the fuel cell gas supply diffusion layer 42 is not formed. (See 7 (c).) In the type AW fuel cell separator 25, a cooling water supply diffusion layer is formed on the surface of the type A fuel cell separator 22 where the fuel cell gas supply diffusion layer 41 is not formed (see FIG. 7 (d)).
　燃料電池スタック２０を運転すると、アノードガス（水素ガス）を導入する燃料極ではプロトン（Ｈ＋）が生成する。プロトンは、膜電極接合体８１中を拡散して酸素極側に移動し、酸素と反応して水が生成する。生成した水は、酸素極側から排出される。このとき、上記のような構造を有する燃料電池用ガス供給拡散層４２を備える燃料電池用セパレータ２３においては、カソードガス流入口６２Ａから流入した空気は流入通路５７及び流入側溝５１からガス拡散部４３に入り、伏流した空気は、孤立穴５５を経由することで移動抵抗が大きい多孔質体内通過する距離を減らせるため、孤立穴５５間を渡り進むようにして流出側に向かう。孤立穴５５に流入した空気は、孤立穴５５内に広がり、孤立穴５５の内表面から再びガス拡散部４３に押し出されて強制伏流させられてさまざまな方向に拡散する。 When the fuel cell stack 20 is operated, protons (H +) are generated at the fuel electrode into which the anode gas (hydrogen gas) is introduced. Protons diffuse through the membrane electrode assembly 81 and move to the oxygen electrode side, and react with oxygen to produce water. The generated water is discharged from the oxygen electrode side. At this time, in the fuel cell separator 23 including the fuel cell gas supply diffusion layer 42 having the above-described structure, the air flowing in from the cathode gas inlet 62A passes through the inflow passage 57 and the inflow side groove 51 to the gas diffusion portion 43. The air that has entered and flows down passes through the isolated hole 55 to reduce the distance that it passes through the porous body having a high movement resistance, and thus travels between the isolated holes 55 toward the outflow side. The air that has flowed into the isolated hole 55 spreads into the isolated hole 55, is pushed out again from the inner surface of the isolated hole 55 to the gas diffusion portion 43, is forced downflow, and diffuses in various directions.
　空気が孤立穴５５間を渡り進むようにして流出側に向かうことを図４及び図６（ａ）を参照してさらに詳しく説明すると、孤立穴５５は空洞であり空気の移動抵抗がガス拡散部４３よりも小さくなるため、空気は、ガス拡散部４３を通過するよりも孤立穴５５を通過しようとする。このため、一の孤立穴５５１からガス拡散部４３に平面方向に押し出された空気は、下流側に近接する第１近接孤立穴５５２又は第２近接孤立穴５５３に向かって伏流する。特に、第１間隔Ｌ１と第２間隔Ｌ２とが「Ｌ１≦Ｌ２」の関係を満たす場合には、一の孤立穴５５１から第２近接孤立穴５５３までのガス拡散部４３を通過する距離（第２間隔Ｌ２）が第１近接孤立穴５５２までのガス拡散部４３を通過する距離（第１間隔Ｌ１）と同じ又はより短くなり、一の孤立穴５５１から押し出された空気の多くは、Ｘ方向にずれて第２近接孤立穴５５３に向かって伏流する。第２近接孤立穴５５３に流入した空気は、再びガス拡散部４３に押し出され、同様にして、第２近接孤立穴５５３の上流に隣接する孤立穴に向けて伏流する。このような繰り返しにより、空気が孤立穴５５間を渡り進むようにして流出側に向かう。 In more detail, referring to FIGS. 4 and 6A, the air travels between the isolated holes 55 and travels toward the outflow side. The isolated holes 55 are hollow, and the movement resistance of the air is greater than that of the gas diffusion portion 43. Therefore, the air tends to pass through the isolated hole 55 rather than through the gas diffusion portion 43. For this reason, the air pushed out in the plane direction from the one isolated hole 551 to the gas diffusion portion 43 flows down toward the first adjacent isolated hole 552 or the second adjacent isolated hole 553 that is close to the downstream side. In particular, when the first interval L1 and the second interval L2 satisfy the relationship “L1 ≦ L2”, the distance (first interval) from the one isolated hole 551 to the second adjacent isolated hole 553 that passes through the gas diffusion portion 43. 2 interval L2) is equal to or shorter than the distance (first interval L1) passing through the gas diffusion part 43 to the first adjacent isolated hole 552, and most of the air pushed out from one isolated hole 551 is in the X direction. And drift down toward the second adjacent isolated hole 553. The air that has flowed into the second adjacent isolated hole 553 is pushed out again to the gas diffusion portion 43 and similarly flows down toward the isolated hole adjacent to the upstream of the second adjacent isolated hole 553. By such repetition, the air travels between the isolated holes 55 toward the outflow side.
　また、第１間隔Ｌ１と第２間隔Ｌ２とが「Ｌ１＜２×Ｌ２」の関係をさらに満たす場合には、一の孤立穴５５１から直接第１近接孤立穴５５２までのガス拡散部４３を通過する距離（第１間隔Ｌ１）が一の孤立穴５５１から第２近接孤立穴５５３を経由して第１近接孤立穴５５２までのガス拡散部４３を通過する距離（２×第２間隔Ｌ２）より短くなり、空気の一部は、一の孤立穴５５１から直接第１近接孤立穴５５２に向かうルートで伏流する。 When the first interval L1 and the second interval L2 further satisfy the relationship of “L1 <2 × L2”, the gas passes through the gas diffusion portion 43 from one isolated hole 551 to the first adjacent isolated hole 552 directly. The distance (first interval L1) to pass through the gas diffusion portion 43 from one isolated hole 551 to the first adjacent isolated hole 552 via the second adjacent isolated hole 553 is greater than the distance (2 × second interval L2). The air becomes shorter, and a part of the air flows down along a route from the one isolated hole 551 directly to the first adjacent isolated hole 552.
　また、図６（ｂ）に示すように、空気は、多孔質体層４０（ガス拡散部４３）内を平面方向に拡散しながら厚さ方向にも拡散し、多孔質体層４０（ガス拡散部４３）に接して設けられた膜電極接合体８１に供給され、発電反応に寄与する。発電に使用されなかったガス（未使用の酸素ガス及び窒素ガス）及び発電時に生成した水（水蒸気又は凝縮水）は多孔質体層４０（ガス拡散部４３）、孤立穴５５、流出側溝５２を介して流出通路５８に流出する。流出通路５８に流出した酸素ガス、窒素ガス及び水は、最終的に流出通路５８からカソードガス流出口６２Ｂ及びカソードガス排出口７２Ｂを通って排出されていく。このとき、燃料電池用ガス供給拡散層４２の構造上、全ての水は排出されず、一部が多孔質体層４０（ガス拡散部４３）内に留まる。 Further, as shown in FIG. 6B, the air diffuses in the thickness direction while diffusing in the plane direction in the porous body layer 40 (gas diffusion portion 43), and the porous body layer 40 (gas diffusion). To the membrane electrode assembly 81 provided in contact with the portion 43) and contributes to the power generation reaction. Gas that has not been used for power generation (unused oxygen gas and nitrogen gas) and water generated during power generation (water vapor or condensed water) pass through the porous body layer 40 (gas diffusion portion 43), the isolated hole 55, and the outflow side groove 52. To the outflow passage 58. The oxygen gas, nitrogen gas and water flowing out to the outflow passage 58 are finally discharged from the outflow passage 58 through the cathode gas outlet 62B and the cathode gas outlet 72B. At this time, due to the structure of the fuel cell gas supply diffusion layer 42, all the water is not discharged and a part of the water stays in the porous body layer 40 (gas diffusion portion 43).
　実施形態に係る燃料電池用ガス供給拡散層４２は、上記のような特徴を有することから、発電時に膜電極接合体で生成した水（水蒸気又は凝縮水）を、多孔質体層４０及び孤立穴５５を介して孤立穴外に効率良く排出できるようになる。また、伏流領域においては伏流ガス流れに押し出される形で水を孤立穴外に効率良く排出できるようになる。 Since the fuel cell gas supply diffusion layer 42 according to the embodiment has the above-described characteristics, water (water vapor or condensed water) generated in the membrane electrode assembly during power generation is converted into the porous body layer 40 and the isolated holes. Through 55, it can be efficiently discharged out of the isolated hole. In the downflow region, water can be efficiently discharged out of the isolated hole while being pushed out by the downflow gas flow.
　また、実施形態に係る燃料電池用ガス供給拡散層４２を、カソードガス用の燃料電池用ガス供給拡散層に利用した場合には、特に顕著な効果が得られる。この場合には、上記のような特徴を有することから、発電に使用されなかったカソードガスを、ガス拡散部４３（多孔質体）及び孤立穴５５を介して効率良く回収できるようになるため、従来よりも燃料電池の発電効率をより一層高くできる、燃料電池用ガス供給拡散層となる。さらにまた、上記のような特徴を有することから、発電時に膜電極接合体８１で生成した水蒸気又は凝集水を、ガス拡散部４３（多孔質体）及び孤立穴５５を介して効率良く回収できるようになるため、従来よりも排水性に優れた燃料電池用ガス供給拡散層となる。 Further, when the fuel cell gas supply diffusion layer 42 according to the embodiment is used for a fuel cell gas supply diffusion layer for cathode gas, a particularly remarkable effect is obtained. In this case, since the cathode gas that has not been used for power generation can be efficiently recovered through the gas diffusion portion 43 (porous body) and the isolated hole 55 because it has the characteristics as described above, The fuel cell gas supply diffusion layer can further increase the power generation efficiency of the fuel cell as compared with the prior art. Furthermore, since it has the above characteristics, it is possible to efficiently recover the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation via the gas diffusion portion 43 (porous body) and the isolated hole 55. Therefore, the fuel cell gas supply diffusion layer is superior in drainage than the conventional one.
　実施形態に係る燃料電池用ガス供給拡散層４２を、カソードガスが空気である場合に特に顕著な効果が得られる。この場合には、上記のような特徴を有することから、発電に使用されない窒素ガスをガス拡散部４３（多孔質体）及び孤立穴５５を介して効率良く排出できるようになるため、従来よりも燃料電池用ガスの移動抵抗を低くでき、従来よりも燃料電池の発電効率をより一層高くできる、燃料電池用ガス供給拡散層となる。 The fuel cell gas supply diffusion layer 42 according to the embodiment is particularly effective when the cathode gas is air. In this case, since it has the characteristics as described above, nitrogen gas that is not used for power generation can be efficiently discharged through the gas diffusion portion 43 (porous body) and the isolated hole 55. The fuel cell gas supply diffusion layer can reduce the movement resistance of the fuel cell gas and can further increase the power generation efficiency of the fuel cell as compared with the conventional one.
　実施形態に係る燃料電池用セパレータ２３は、金属板３０と、金属板３０の少なくとも一方の面に配設された燃料電池用ガス供給拡散層とを備える燃料電池用セパレータであって、燃料電池用ガス供給拡散層が実施形態に係る
燃料電池用ガス供給拡散層４２であり、当該燃料電池用ガス供給拡散層４２は、複数のガス流路用溝５５が金属板３０側に位置するように金属板３０に対して配置されており、ガス流路用溝５５と金属板３０とでガス流路が構成されていることから、従来よりも燃料電池の発電効率を高くでき、さらには、従来よりも排水性に優れた、燃料電池用セパレータとなる。 The fuel cell separator 23 according to the embodiment is a fuel cell separator including a metal plate 30 and a fuel cell gas supply diffusion layer disposed on at least one surface of the metal plate 30. The gas supply diffusion layer is the fuel cell gas supply diffusion layer 42 according to the embodiment, and the fuel cell gas supply diffusion layer 42 is made of metal such that the plurality of gas flow channel grooves 55 are located on the metal plate 30 side. Since the gas flow path is constituted by the gas flow path groove 55 and the metal plate 30, it is possible to increase the power generation efficiency of the fuel cell as compared with the prior art. The fuel cell separator is excellent in drainage.
　また、実施形態に係る燃料電池セルスタック２０は、燃料電池用セパレータと、膜電極接合体とが積層されてなる燃料電池セルスタックであって、燃料電池用セパレータが、実施形態に係る燃料電池用セパレータ２３であり、当該燃料電池用セパレータ２３と膜電極接合体８１とは、燃料電池用ガス供給拡散層４２の複数のガス流路用溝５５が形成されていない側の面に膜電極接合体８１が位置する位置関係で積層されていることから、従来よりも燃料電池の発電効率を高くでき、さらには、従来よりも排水性に優れた、燃料電池セルスタックとなる。 The fuel cell stack 20 according to the embodiment is a fuel cell stack in which a fuel cell separator and a membrane electrode assembly are stacked, and the fuel cell separator is the fuel cell stack according to the embodiment. The separator 23 for the fuel cell and the membrane electrode assembly 81 are the membrane electrode assembly on the surface of the fuel cell gas supply diffusion layer 42 where the plurality of gas flow channel grooves 55 are not formed. Since the layers 81 are stacked in a positional relationship, the fuel cell power generation efficiency can be increased as compared with the conventional case, and further, the fuel cell stack can be more excellent in drainage than the conventional case.
［燃料電池用セパレータ２３の製造方法］
　一例として、耐食層、緻密枠３２、燃料電池用ガス供給拡散層４２等は等方圧加圧により形成する。たとえば熱硬化性樹脂を用いる場合（熱可塑性樹脂でもよい）、炭素系導電材粉末（及び、状況に応じて炭素繊維）、樹脂粉末及び揮発性溶剤を混錬してペースト状にする。このペーストには、耐食層、及び緻密枠用のもの、流体供給拡散層用のもの等、多数種類を用意しておく。そして、金属板３０上に、耐食層、緻密枠３２のパターン、燃料電池用ガス供給拡散層４２のパターン等を順次プリント、スタンプ、絞り出し等により形成する。各パターンの形成ごとに溶剤を揮発させる。上記のすべてのパターンが形成された金属板３０の全体を軟質の薄いゴムバックに入れ、真空に脱気した後、ゴムバックを耐圧容器に入れ、加熱流体を容器内に導入して、加熱流体で等方圧加圧して樹脂を硬化させる。緻密枠３２、燃料電池用ガス供給拡散層４２の高さ（厚さ）を最終的に同じ高さ（厚さ）にするために、樹脂硬化の際の収縮の程度に応じて、これらの各枠、壁、層等の高さ（厚さ）をパターン作製時に調整しておくことが好ましい。 [Manufacturing Method of Fuel Cell Separator 23]
As an example, the corrosion-resistant layer, the dense frame 32, the fuel cell gas supply diffusion layer 42, and the like are formed by isotropic pressure. For example, when a thermosetting resin is used (a thermoplastic resin may be used), carbon-based conductive material powder (and carbon fiber depending on the situation), resin powder, and volatile solvent are kneaded to form a paste. Many types of pastes, such as a corrosion-resistant layer, a dense frame, and a fluid supply diffusion layer, are prepared. Then, a corrosion-resistant layer, a dense frame 32 pattern, a fuel cell gas supply diffusion layer 42 pattern, and the like are sequentially formed on the metal plate 30 by printing, stamping, squeezing, and the like. The solvent is volatilized for each pattern formation. The whole metal plate 30 on which all the above patterns are formed is put in a soft thin rubber bag, degassed to a vacuum, and then the rubber bag is put in a pressure vessel, and a heating fluid is introduced into the vessel. Press the isotropic pressure to cure the resin. In order to finally make the height (thickness) of the dense frame 32 and the fuel cell gas supply diffusion layer 42 the same height (thickness), each of these may be selected according to the degree of shrinkage during resin curing. It is preferable to adjust the height (thickness) of the frame, wall, layer, and the like at the time of pattern formation.
　一方で、金属板３０上に耐食層を形成しておき、他方で緻密枠３２、燃料電池用ガス供給拡散層４２を形成し、最後にこれらを熱圧着して製造することもできる。このとき緻密枠３２は金属板３０上の耐食層と同時に作成してもよい。第１段階で金属板３０上に耐食層と緻密枠３２とを作成し、この後第２段階で燃料電池用ガス供給拡散層４２のペーストを金属板３０の耐食層上に順次印刷し、乾燥させた後、ロールプレス（ホットプレス）で硬化させて製造することもできる。 Alternatively, a corrosion-resistant layer can be formed on the metal plate 30, the dense frame 32 and the fuel cell gas supply diffusion layer 42 can be formed on the other side, and finally these can be manufactured by thermocompression bonding. At this time, the dense frame 32 may be formed simultaneously with the corrosion-resistant layer on the metal plate 30. In the first stage, a corrosion-resistant layer and a dense frame 32 are formed on the metal plate 30, and then in the second stage, the paste of the fuel cell gas supply diffusion layer 42 is sequentially printed on the corrosion-resistant layer of the metal plate 30 and dried. After making it harden | cure with a roll press (hot press), it can also manufacture.
　または、次のような製造方法を用いることもできる。カーボンファイバー（ＣＦ）、少量の黒煙微粒子（ＧＣＢ）及び結着剤となる熱可塑性もしくは熱硬化性又は繊維状物を形成する樹脂を混錬してシート状に形成し、硬化する前のグリーンシート状態のときに、流入通路５７、流出通路５８、流入側溝５１、流出側溝５２及孤立穴５５に対応する形状の突起を有するスタンプ型をシートに押し当てて、流入通路５７、流出通路５８、流入側溝５１、流出側溝５２及孤立穴５５を形成する。最後にグリーンシートを熱処理し、これを耐食層が形成された金属板３０に接着する。 Alternatively, the following manufacturing method can be used. Green before being cured by kneading carbon fiber (CF), a small amount of black smoke fine particles (GCB), and a thermoplastic or thermosetting resin as a binder or a resin that forms a fibrous material into a sheet. In the sheet state, a stamp mold having a shape corresponding to the inflow passage 57, the outflow passage 58, the inflow side groove 51, the outflow side groove 52, and the isolated hole 55 is pressed against the sheet, and the inflow passage 57, the outflow passage 58, An inflow side groove 51, an outflow side groove 52, and an isolated hole 55 are formed. Finally, the green sheet is heat treated and bonded to the metal plate 30 on which the corrosion resistant layer is formed.
　燃料電池用ガス供給拡散層４２の移動抵抗（又は流体抵抗）は、多孔質体層４０の気孔率と流体の流れる方向に直交する面の面積（各層の高さ（厚さ）と幅）に依存する。気孔率が大きくなれば移動抵抗は小さくなる。流体が流れる面積が大きくなれば移動抵抗は小さくなる（単位面積当りの移動抵抗は一定である）。おおよその目安としては、燃料電池用ガス供給拡散層の気孔率は、（アノードガス用）燃料電池用ガス供給拡散層４２については３０～８５％程度、（カソードガス用）燃料電池用ガス供給拡散層４１については５０～８５％程度である。気孔率Ｐは、測定が容易な、Ｐ＝（多孔質体層中の気孔の体積）／（多孔質体層の体積）で定められる。ここで、気孔は外部に通じていない気孔を含む真の気孔である。 The movement resistance (or fluid resistance) of the fuel cell gas supply diffusion layer 42 is the surface area (height (thickness) and width of each layer) orthogonal to the porosity of the porous body layer 40 and the fluid flow direction. Dependent. If the porosity increases, the movement resistance decreases. If the area through which the fluid flows increases, the movement resistance decreases (the movement resistance per unit area is constant). As a rough guide, the porosity of the fuel cell gas supply diffusion layer is about 30 to 85% for the fuel cell gas supply diffusion layer 42 (for the anode gas), and the fuel cell gas supply diffusion for the cathode gas. The layer 41 is about 50 to 85%. The porosity P is determined by P = (volume of pores in the porous body layer) / (volume of porous body layer), which is easy to measure. Here, the pores are true pores including pores that do not communicate with the outside.
　なお、上記した製造方法は、燃料電池用セパレータ２３以外の燃料電池用セパレータ（燃料電池用セパレータ２１、燃料電池用セパレータ２２、燃料電池用セパレータ２４及び燃料電池用セパレータ２５）を製造する際にも適用できる。 The manufacturing method described above is also used when manufacturing fuel cell separators other than the fuel cell separator 23 (fuel cell separator 21, fuel cell separator 22, fuel cell separator 24, and fuel cell separator 25). Applicable.
［燃料電池用セパレータ２３以外の燃料電池用セパレータ］
　図７は、燃料電池用セパレータ２３以外の燃料電池用セパレータ（燃料電池用セパレータ２１、燃料電池用セパレータ２２、燃料電池用セパレータ２４及び燃料電池用セパレータ２５）の断面図である。図７（ａ）はタイプＣＡの燃料電池用セパレータ２１の断面図であり、図７（ｂ）はタイプＡの燃料電池用セパレータ２２の断面図であり、図７（ｃ）はタイプＣＷの燃料電池用セパレータ２４の断面図であり、図７（ｄ）はタイプＡＷの燃料電池用セパレータ２５の断面図である。 [Fuel cell separators other than the fuel cell separator 23]
FIG. 7 is a cross-sectional view of a fuel cell separator (a fuel cell separator 21, a fuel cell separator 22, a fuel cell separator 24, and a fuel cell separator 25) other than the fuel cell separator 23. 7A is a sectional view of a fuel cell separator 21 of type CA, FIG. 7B is a sectional view of a fuel cell separator 22 of type A, and FIG. 7C is a fuel of type CW. FIG. 7D is a cross-sectional view of a battery separator 24, and FIG. 7D is a cross-sectional view of a fuel cell separator 25 of type AW.
　本発明の燃料電池用ガス供給拡散層は、燃料電池用セパレータ２１の（カソードガス用）燃料電池用ガス供給拡散層４２及び／又は（アノードガス用）燃料電池用ガス供給拡散層４１に適用することができる（図７（ａ）参照。）。また、本発明の燃料電池用ガス供給拡散層は、燃料電池用セパレータ２２の（アノードガス用）燃料電池用ガス供給拡散層４１に適用することができる（図７（ｂ）参照。）。また、本発明の燃料電池用ガス供給拡散層は、燃料電池用セパレータ２４の（カソードガス用）燃料電池用ガス供給拡散層４２に適用することができる（図７ｃ）参照。）。また、本発明の燃料電池用ガス供給拡散層は、燃料電池用セパレータ２５の（アノードガス用）燃料電池用ガス供給拡散層４１に適用することができる（図７（ｂ）参照。）。 The fuel cell gas supply diffusion layer of the present invention is applied to the fuel cell gas supply diffusion layer (for cathode gas) 42 and / or the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 21. (See FIG. 7 (a)). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 22 (see FIG. 7B). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 42 (for cathode gas) of the fuel cell separator 24 (see FIG. 7c). ). Further, the fuel cell gas supply diffusion layer of the present invention can be applied to the fuel cell gas supply diffusion layer 41 (for anode gas) of the fuel cell separator 25 (see FIG. 7B).
　このように本発明の燃料電池用ガス供給拡散層を上記のような燃料電池用セパレータ２１，２２，２４，２５の燃料電池用ガス供給拡散層に適用した場合であっても、従来よりも多量の燃料電池用ガスを膜電極接合体に対して均一に供給できるようになることから、従来よりも燃料電池の発電効率を高くできる、燃料電池用ガス供給拡散層となる。 As described above, even when the fuel cell gas supply diffusion layer of the present invention is applied to the fuel cell gas supply diffusion layers of the fuel cell separators 21, 22, 24, and 25 as described above, a larger amount than in the conventional case. Since the fuel cell gas can be uniformly supplied to the membrane electrode assembly, it becomes a fuel cell gas supply diffusion layer that can increase the power generation efficiency of the fuel cell as compared with the conventional case.
[構成例１]
　本発明の１実施形態として図４に示すような燃料電池用ガス供給拡散層の構成例を示すことができる。すなわち図４では、上述のような基本構成の加え、所定の規則性として、Ｘ方向に等ピッチ（Ｘピッチ）で並んだＹ方向に延びる複数の線上に、Ｙ方向に等ピッチ（Ｙピッチ）で配置されている。孤立穴５５は、Ｙ方向の並びを１列としＸ方向の端側からｎ列とすると、奇数列同士及び偶数列同士のＹ方向の位置が同じで、奇数列と偶数列とのＹ方向の位置がＹピッチの半分ずれている（いわゆる千鳥パターン構成である）。このように、孤立穴５５は、Ｘ方向及びＹ方向に規則性をもたせて配置されている。また、図４では、各孤立穴５５は、形や大きさを含め、全て同形状であり 、各孤立穴５５が多孔質体層４０の一方の面に配置されている。各孤立穴５５は、幅が変化している形状であり、具体的には円形である。各孤立穴５５は、ガス流入側溝５１及びガス流出側溝５２と同じ深さ、且つ一定の深さで形成されている。各孤立穴５５は、内表面に多孔質体からなるガス拡散部４３が露出している。 [Configuration example 1]
As an embodiment of the present invention, a configuration example of a fuel cell gas supply diffusion layer as shown in FIG. 4 can be shown. That is, in FIG. 4, in addition to the basic configuration as described above, as a predetermined regularity, on a plurality of lines extending in the Y direction arranged at equal pitch (X pitch) in the X direction, equal pitch (Y pitch) in the Y direction. Is arranged in. If the isolated holes 55 are arranged in the Y direction as one column and n columns from the end in the X direction, the positions of the odd columns and the even columns in the Y direction are the same. The position is shifted by half the Y pitch (so-called staggered pattern configuration). Thus, the isolated holes 55 are arranged with regularity in the X direction and the Y direction. In FIG. 4, each isolated hole 55 has the same shape including shape and size, and each isolated hole 55 is arranged on one surface of the porous body layer 40. Each isolated hole 55 has a shape that changes in width, and specifically has a circular shape. Each isolated hole 55 is formed with the same depth as the gas inflow side groove 51 and the gas outflow side groove 52 and a constant depth. In each isolated hole 55, the gas diffusion portion 43 made of a porous body is exposed on the inner surface.
　このようにすれば、上記した効果に加え、さらに複数の孤立穴５５が多孔質体層４０の一方の面の全面にわたって分散しているため、燃料電池用ガスを多孔質体層４０全体にわたってより均一に拡散させることができる。 In this way, in addition to the effects described above, the plurality of isolated holes 55 are dispersed over the entire surface of one surface of the porous body layer 40, so that the fuel cell gas is more spread over the entire porous body layer 40. It can be diffused uniformly.
［変形例１］
　図８は、変形例１に係る燃料電池用ガス供給拡散層４２ａの（金属板３０の側から見た）平面構造を説明するために示す図である。但し、図４の場合と同様に、燃料電池用セパレータ２３の流路パターンを分かり易く表すために、金属板３０の図示は省略している。以降の図９～図１７においても同様である。 [Modification 1]
FIG. 8 is a view for explaining a planar structure (seen from the metal plate 30 side) of the fuel cell gas supply diffusion layer 42a according to the first modification. However, as in the case of FIG. 4, the metal plate 30 is not shown in order to easily show the flow path pattern of the fuel cell separator 23. The same applies to the following FIG. 9 to FIG.
　変形例１に係る燃料電池用ガス供給拡散層４２ａは、基本的には実施形態に係る燃料電池用ガス供給拡散層４２と同様の構成を有するが、孤立穴の平面形状が実施形態に係る燃料電池用ガス供給拡散層４２の場合と異なる。すなわち、図８に示すように、変形例１に係る燃料電池用ガス供給拡散層４２ａにおいては、孤立穴として平面形状が菱形である孤立穴５５ａを用いている。 The fuel cell gas supply diffusion layer 42a according to Modification 1 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 8, in the fuel cell gas supply diffusion layer 42 a according to the first modification, an isolated hole 55 a having a rhombic planar shape is used as the isolated hole.
　変形例１に係る燃料電池用ガス供給拡散層４２ａによれば、実施形態に係る燃料電池用ガス供給拡散層４２と同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、孤立穴５５ａが平面状の壁面を有し、近接する孤立穴５５ａ同士の壁面を平行に配置することが可能となることから、孤立穴５５ａ間の流体抵抗がある程度広い範囲で一定になり、より燃料電池用ガスを均一に伏流させることができる。 According to the fuel cell gas supply diffusion layer 42a according to the modified example 1, in addition to the same effects as the fuel cell gas supply diffusion layer 42 according to the embodiment, the following effects can be obtained. That is, the isolated hole 55a has a flat wall surface, and the wall surfaces of the adjacent isolated holes 55a can be arranged in parallel, so that the fluid resistance between the isolated holes 55a becomes constant over a wide range. Thus, the fuel cell gas can be more uniformly downflowed.
［変形例２］
　図９は、変形例２に係る燃料電池用ガス供給拡散層４２ｂの平面構造を説明するために示す図である。 [Modification 2]
FIG. 9 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42b according to the second modification.
　変形例２に係る燃料電池用ガス供給拡散層４２ｂは、基本的には実施形態に係る燃料電池用ガス供給拡散層４２と同様の構成を有するが、孤立穴の平面形状が実施形態に係る燃料電池用ガス供給拡散層４２の場合と異なる。すなわち、図９に示すように、変形例２に係る燃料電池用ガス供給拡散層４２ｂにおいては、孤立穴として幅が一定の平面形状（この場合、Ｙ方向に沿って延びる長方形）である孤立穴５５ｂを用いている。 The fuel cell gas supply diffusion layer 42b according to Modification 2 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 9, in the fuel cell gas supply diffusion layer 42b according to the modified example 2, the isolated hole is a planar shape having a constant width as an isolated hole (in this case, a rectangle extending along the Y direction). 55b is used.
　変形例２に係る燃料電池用ガス供給拡散層４２ｂによれば、実施形態に係る燃料電池用ガス供給拡散層４２と同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、孤立穴５５ｂの幅が一定、すなわち平面形状が正方形又は長方形であることから、特に多孔質体層の平面形状が矩形の場合に、孤立穴５５ｂを多孔質体層の一方の面の全体にわたって配置しやすくできる。 According to the fuel cell gas supply diffusion layer 42b according to Modification 2, in addition to the same effects as the fuel cell gas supply diffusion layer 42 according to the embodiment, the following effects can be obtained. That is, since the width of the isolated hole 55b is constant, that is, the planar shape is square or rectangular, the isolated hole 55b is formed on the entire one surface of the porous body layer, particularly when the planar shape of the porous body layer is rectangular. Easy to place over.
［変形例３］
　図１０は、変形例３に係る燃料電池用ガス供給拡散層４２ｃの平面構造を説明するために示す図である。 [Modification 3]
FIG. 10 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42c according to the third modification.
　変形例３に係る燃料電池用ガス供給拡散層４２ｃは、基本的には実施形態に係る燃料電池用ガス供給拡散層４２と同様の構成を有するが、孤立穴の平面形状が実施形態に係る燃料電池用ガス供給拡散層４２の場合と異なる。すなわち、図１０に示すように、変形例３に係る燃料電池用ガス供給拡散層４２ｃにおいては、孤立穴として斜めの方向に沿って延びている孤立溝である孤立穴５５ｃを用いている。 The fuel cell gas supply diffusion layer 42c according to the modified example 3 basically has the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 10, in the fuel cell gas supply diffusion layer 42 c according to Modification 3, an isolated hole 55 c that is an isolated groove extending along an oblique direction is used as the isolated hole.
　変形例３に係る燃料電池用ガス供給拡散層４２ｃによれば、実施形態に係る燃料電池用ガス供給拡散層４２と同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、孤立穴５５ｃが斜めの方向に沿って延びている孤立溝であることから、燃料電池用ガスをＸ方向に広げるとともにＹ方向に進行させることができる。 According to the fuel cell gas supply diffusion layer 42c according to the modified example 3, in addition to the same effects as the fuel cell gas supply diffusion layer 42 according to the embodiment, the following effects can be obtained. That is, since the isolated hole 55c is an isolated groove extending along an oblique direction, the fuel cell gas can be expanded in the X direction and advanced in the Y direction.
［変形例４］
　図１１は、変形例４に係る燃料電池用ガス供給拡散層４２ｄの平面構造を説明するために示す図である。 [Modification 4]
FIG. 11 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42d according to Modification 4.
　変形例４に係る燃料電池用ガス供給拡散層４２ｄは、基本的には実施形態に係る燃料電池用ガス供給拡散層４２と同様の構成を有するが、孤立穴の平面形状が実施形態に係る燃料電池用ガス供給拡散層４２の場合と異なる。すなわち、図１１に示すように、変形例４に係る燃料電池用ガス供給拡散層４２ｄにおいては、孤立穴として途中で曲がっている孤立穴５５ｄを用いている。途中で曲がっている孤立穴５５ｄの形状としては、例えば図１１に示すようなＬ字形状の他、Ｕ字、Ｃ字、円弧などの形状を挙げることができる。なお、孤立穴５５ｄは、図１１の２点鎖線Ｇで表すジグザグのライン上に沿って、間欠的に配置されている。 The fuel cell gas supply diffusion layer 42d according to Modification 4 has basically the same configuration as the fuel cell gas supply diffusion layer 42 according to the embodiment, but the planar shape of the isolated hole is the fuel according to the embodiment. This is different from the case of the battery gas supply diffusion layer 42. That is, as shown in FIG. 11, in the fuel cell gas supply diffusion layer 42d according to Modification 4, an isolated hole 55d that is bent in the middle is used as the isolated hole. Examples of the shape of the isolated hole 55d that is bent in the middle include, for example, U-shape, C-shape, arc shape, and the like in addition to the L-shape as shown in FIG. The isolated holes 55d are intermittently arranged along a zigzag line represented by a two-dot chain line G in FIG.
　変形例４に係る燃料電池用ガス供給拡散層４２ｄによれば、実施形態に係る燃料電池用ガス供給拡散層４２と同様の効果が得られるのに加えて、孤立穴５５ｄが途中で曲がっていることで、燃料電池用ガスを素早く方向を変えて広げることができるという効果が得られる。 According to the fuel cell gas supply diffusion layer 42d according to the modified example 4, in addition to obtaining the same effect as the fuel cell gas supply diffusion layer 42 according to the embodiment, the isolated hole 55d is bent in the middle. As a result, it is possible to obtain an effect that the fuel cell gas can be quickly changed in direction and spread.
［変形例５］
　図１２は、変形例５に係る燃料電池用ガス供給拡散層４２ｅの平面構造を説明するために示す図である。 [Modification 5]
FIG. 12 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42e according to the fifth modification.
　変形例５に係る燃料電池用ガス供給拡散層４２ｅは、基本的には変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の構成を有するが、孤立穴の平面構造が変形例２に係る燃料電池用ガス供給拡散層４２ｂの場合と異なる。すなわち、図１２に示すように、変形例４に係る燃料電池用ガス供給拡散層４２ｅにおいては、孤立穴５５ｅが下流側にいくに従って平面的に見た面積が段階的に小さくなるように形成されている。図１２では、図９に示したものと同様に長方形の孤立穴を構成した例を示している。ここで孤立穴５５ｅが流入側から流出側に向かうに従って、長方形の孤立穴５５ｅのＸ方向の長さ(幅）がＷ１＞Ｗ２＞Ｗ３と段階的に細くなるように形成されている。 The fuel cell gas supply diffusion layer 42e according to the modification 5 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the planar structure of the isolated hole is the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 12, in the fuel cell gas supply diffusion layer 42e according to the modified example 4, the isolated hole 55e is formed in such a manner that the area seen in a plane is gradually reduced as it goes downstream. ing. FIG. 12 shows an example in which rectangular isolated holes are formed in the same manner as that shown in FIG. Here, as the isolated hole 55e moves from the inflow side to the outflow side, the length (width) in the X direction of the rectangular isolated hole 55e is formed so as to be gradually reduced as W1> W2> W3.
　変形例５に係る燃料電池用ガス供給拡散層４２ｅによれば、変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、孤立穴５５ｅが下流側にいくに従って平面的に見た面積が段階的に小さくなるため、下流側にいくに従って減っていく燃料電池用ガスの流量に対応するようになる。このため、上流側と下流側との燃料電池用ガスの濃度がより均一になり、燃料電池用ガスを効率よく拡散できる。 According to the fuel cell gas supply diffusion layer 42e according to the modified example 5, in addition to the same effects as the fuel cell gas supply diffusion layer 42b according to the modified example 2, the following effects can be obtained. That is, as the isolated hole 55e goes to the downstream side, the area seen in a plan view becomes smaller in steps, so that it corresponds to the flow rate of the fuel cell gas decreasing toward the downstream side. For this reason, the concentration of the fuel cell gas on the upstream side and the downstream side becomes more uniform, and the fuel cell gas can be diffused efficiently.
［変形例６］
　図１３は、変形例６に係る燃料電池用ガス供給拡散層４２ｆの平面構造を説明するために示す図である。 [Modification 6]
FIG. 13 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42f according to Modification 6.
　変形例６に係る燃料電池用ガス供給拡散層４２ｆは、基本的には変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の構成を有するが、孤立穴の平面構造が変形例２に係る燃料電池用ガス供給拡散層４２ｂの場合と異なる。すなわち、図１３に示すように、変形例６に係る燃料電池用ガス供給拡散層４２ｆにおいては、孤立穴５５ｆが下流側にいくに従って平面的に見た面積が段階的に小さくなるように形成されている。図１３では、図９に示したものと同上に長方形の孤立穴５５ｅを構成した例を示している。ここで孤立穴５５ｆが流入側から流出側に向かうに従って、長方形の孤立穴５５ｅのＹ方向の長さがＤ１＞Ｄ２＞Ｄ３と段階的に短くなっている。 The fuel cell gas supply diffusion layer 42f according to the modification 6 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the planar structure of the isolated hole is changed to the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 13, the fuel cell gas supply diffusion layer 42 f according to the modified example 6 is formed so that the area seen in a plane is gradually reduced as the isolated hole 55 f goes downstream. ing. FIG. 13 shows an example in which a rectangular isolated hole 55e is configured in the same manner as that shown in FIG. Here, as the isolated hole 55f moves from the inflow side to the outflow side, the length of the rectangular isolated hole 55e in the Y direction is gradually reduced as D1> D2> D3.
　変形例６に係る燃料電池用ガス供給拡散層４２ｆによれば、変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、孤立穴５５ｆが下流側にいくに従って平面的に見た面積が段階的に小さくなるため、下流側にいくに従って減っていく燃料電池用ガスの流量に対応するようになる。このため、上流側と下流側との燃料電池用ガスの濃度がより均一になり、燃料電池用ガスを効率よく拡散できる。 According to the fuel cell gas supply diffusion layer 42f according to the modification 6, in addition to the same effects as the fuel cell gas supply diffusion layer 42b according to the modification 2, the following effects can be obtained. That is, since the area seen in a plan view decreases stepwise as the isolated hole 55f goes downstream, it corresponds to the flow rate of the fuel cell gas that decreases as it goes downstream. For this reason, the concentration of the fuel cell gas on the upstream side and the downstream side becomes more uniform, and the fuel cell gas can be diffused efficiently.
　なお、変形例５及び変形例６においては、孤立穴として、いずれも長方形の孤立穴（５５ｅ，５５ｆ）として示したが、孤立穴の大きさ(面積）を下流側にいくに従って小さくなるようにすれば、孤立穴は、円、楕円、菱形、三角形などその他の形状でも構わない。また、孤立穴ごとに最適な形状としてもよい。 In Modifications 5 and 6, each of the isolated holes is shown as a rectangular isolated hole (55e, 55f). However, the size (area) of the isolated hole is reduced as it goes downstream. In this case, the isolated hole may have another shape such as a circle, an ellipse, a diamond, or a triangle. Moreover, it is good also as an optimal shape for every isolated hole.
［変形例７］
　図１４は、変形例７に係る燃料電池用ガス供給拡散層４２ｇの平面構造を説明するために示す図である。 [Modification 7]
FIG. 14 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42g according to Modification 7.
　変形例７に係る燃料電池用ガス供給拡散層４２ｇは、基本的には変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の構成を有するが、ガス圧均等化用溝をさらに有する点で変形例２に係る燃料電池用ガス供給拡散層４２ｂの場合と異なる。すなわち、図１４に示すように、変形例７に係る燃料電池用ガス供給拡散層４２ｇにおいては、多孔質体層４０は、多孔質体層４０の一方の面に、多孔質体層４０の幅一杯に延びた１又は複数のガス圧均等化用溝５６（図１４では２本のガス圧均等化用溝５６）をさらに有している。ガス圧均等化用溝５６は多孔質体層４０をＹ方向にほぼ三等分するように２か所に形成されている。ガス圧均等化用溝５６は孤立穴５５ｇと同等の深さで形成されている。ガス圧均等化用溝５６を備えるため、孤立穴５５ｇは、多孔質体層４０の一方の面の内、ガス圧均等化用溝５６同士、流入側溝５１とガス圧均等化用溝５６、あるいは流出側溝５２とガス圧均等化用溝５６にそれぞれ挟まれた範囲（所望の範囲）にわたって分散して配置されている。 The fuel cell gas supply diffusion layer 42g according to the modified example 7 basically has the same configuration as the fuel cell gas supply diffusion layer 42b according to the modified example 2, but further includes a gas pressure equalizing groove. This is different from the fuel cell gas supply diffusion layer 42b according to the second modification. That is, as shown in FIG. 14, in the fuel cell gas supply diffusion layer 42g according to the modified example 7, the porous body layer 40 is formed on one surface of the porous body layer 40 on the width of the porous body layer 40. One or more gas pressure equalizing grooves 56 (two gas pressure equalizing grooves 56 in FIG. 14) are further provided. The gas pressure equalizing grooves 56 are formed at two locations so as to divide the porous body layer 40 into approximately three equal parts in the Y direction. The gas pressure equalizing groove 56 is formed with a depth equivalent to that of the isolated hole 55g. Since the gas pressure equalizing groove 56 is provided, the isolated hole 55g has the gas pressure equalizing grooves 56, the inflow side groove 51 and the gas pressure equalizing groove 56 in one surface of the porous body layer 40, or Dispersed and arranged over a range (desired range) sandwiched between the outflow side groove 52 and the gas pressure equalizing groove 56.
　変形例７に係る燃料電池用ガス供給拡散層４２ｇによれば、変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の効果が得られるのに加えて、多孔質体層４０の幅方向一杯に延びたガス圧均等化用溝５６を有することで、多孔質体層４０の幅方向全体にわたって燃料電池用ガスの供給量をより一層均一にできるという効果が得られる。 According to the fuel cell gas supply diffusion layer 42g according to the modified example 7, in addition to the same effects as the fuel cell gas supply diffusion layer 42b according to the modified example 2, the width direction of the porous body layer 40 can be obtained. By having the gas pressure equalizing groove 56 extending to the full, the supply amount of the fuel cell gas can be made more uniform over the entire width direction of the porous body layer 40.
［変形例８］
　図１５は、変形例８に係る燃料電池用ガス供給拡散層４２ｈの平面構造を説明するために示す図である。 [Modification 8]
FIG. 15 is a view for explaining a planar structure of a fuel cell gas supply diffusion layer 42h according to Modification 8.
　変形例８に係る燃料電池用ガス供給拡散層４２ｈは、基本的には変形例７に係る燃料電池用ガス供給拡散層４２ｇと同様の構成を有するが、ガス圧均等化用溝の本数及び孤立穴の平面構造が変形例７に係る燃料電池用ガス供給拡散層４２ｇの場合と異なる。すなわち、図１５に示すように、変形例８に係る燃料電池用ガス供給拡散層４２ｈにおいては、ガス圧均等化用溝５６が１本だけ形成されている。また、変形例８に係る燃料電池用ガス供給拡散層４２ｈにおいては、複数の孤立穴５５ｈは、下流側にいくに従って、幅方向（Ｘ方向）に近接する孤立穴同士の間隔が段階的に狭くなっている。より詳しくは、孤立穴５５ｈは、ガス圧均等化用溝５６の下流側における孤立穴５５ｈ同士の間隔Ｐ２がガス圧均等化用溝５６の上流側における孤立穴５５ｈ同士の間隔Ｐ２よりも狭くなっている。また、孤立穴５５ｈは、ガス圧均等化用溝５６の下流側における幅がガス圧均等化用溝５６の上流側における幅よりも狭くなっている。変形例８）では、ガス圧均等化用溝５６を１つ備える構成例のため、孤立穴５５ｈは、多孔質体層４０の一方の面の内、流入側溝５１とガス圧均等化用溝５６、あるいは流出側溝５２とガス圧均等化用溝５６に挟まれた範囲（所望の範囲）にわたって分散して配置されている。しかしながら変形例７のようにさらにガス圧均等化用溝５６を加えて、ガス圧均等化用溝５６同士、流入側溝５１とガス圧均等化用溝５６、あるいは流出側溝５２とガス圧均等化用溝５６に挟まれた範囲（所望の範囲）にわたって分散して配置してもよい。変形例８では、流入側溝５１とガス圧均等化用溝５６、あるいは流出側溝５２とガス圧均等化用溝５６に挟まれた範囲（所望の範囲）ごとに孤立穴５５ｈの大きさや形状、分散配置の配置規則とを個別に代えて配置している。 The fuel cell gas supply diffusion layer 42h according to the modified example 8 has basically the same configuration as the fuel cell gas supply diffusion layer 42g according to the modified example 7, but the number of gas pressure equalization grooves and the isolation are isolated. The planar structure of the holes is different from that of the fuel cell gas supply diffusion layer 42g according to the modified example 7. That is, as shown in FIG. 15, in the fuel cell gas supply diffusion layer 42h according to the modification 8, only one gas pressure equalizing groove 56 is formed. Further, in the fuel cell gas supply diffusion layer 42h according to the modified example 8, as the plurality of isolated holes 55h go to the downstream side, the intervals between the isolated holes adjacent in the width direction (X direction) are gradually reduced. It has become. More specifically, in the isolated holes 55h, the interval P2 between the isolated holes 55h on the downstream side of the gas pressure equalizing groove 56 is narrower than the interval P2 between the isolated holes 55h on the upstream side of the gas pressure equalizing groove 56. ing. Further, the isolated hole 55 h has a narrower width on the downstream side of the gas pressure equalizing groove 56 than a width on the upstream side of the gas pressure equalizing groove 56. In the modified example 8), since the gas pressure equalizing groove 56 is provided as one example, the isolated hole 55h has the inflow side groove 51 and the gas pressure equalizing groove 56 in one surface of the porous body layer 40. Alternatively, they are arranged dispersed over a range (desired range) sandwiched between the outflow side groove 52 and the gas pressure equalizing groove 56. However, the gas pressure equalizing grooves 56 are further added as in the modified example 7, and the gas pressure equalizing grooves 56, the inflow side grooves 51 and the gas pressure equalizing grooves 56, or the outflow side grooves 52 and the gas pressure equalizing grooves 56 are used. You may disperse | distribute and arrange | position over the range (desired range) pinched | interposed into the groove | channel 56. FIG. In the modified example 8, the size, shape, and dispersion of the isolated holes 55h for each range (desired range) sandwiched between the inflow side groove 51 and the gas pressure equalization groove 56 or between the outflow side groove 52 and the gas pressure equalization groove 56. The arrangement rules are arranged separately from each other.
　変形例８に係る燃料電池用ガス供給拡散層４２ｈによれば、変形例７に係る燃料電池用ガス供給拡散層４２ｇと同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、Ｘ方向に近接する孤立穴５５ｈ同士の間隔が段階的に狭くなっていることから、Ｘ方向沿った方向に整列している孤立穴５５ｈの数が段階的に多くなる。このため、下流側にいくに従って圧力損失が大きくなっても、伏流する燃料電池用ガス及び発電時に膜電極接合体で生成した水蒸気又は凝集水が、密に配置されている下流側の孤立穴に流れ込みやすくなり、燃料電池用ガスをより均一に拡散させるとともに、発電時に膜電極接合体８１で生成した水蒸気または凝集水をより効率良く燃料電池用ガス供給拡散層４２ｈ外に排出できる。また、ガス圧均等化用溝５６の下流において、より均一に燃料電池用ガスを拡散させることができる。 According to the fuel cell gas supply diffusion layer 42h according to the modified example 8, in addition to the same effects as the fuel cell gas supply diffusion layer 42g according to the modified example 7, the following effects can be obtained. That is, since the interval between the isolated holes 55h adjacent to each other in the X direction is gradually reduced, the number of isolated holes 55h aligned in the direction along the X direction is increased stepwise. For this reason, even if the pressure loss increases toward the downstream side, the fuel cell gas flowing down and the water vapor or condensed water generated in the membrane electrode assembly at the time of power generation are in close contact with the downstream isolated holes. The fuel cell gas is more easily diffused, and the water vapor or the condensed water generated in the membrane electrode assembly 81 during power generation can be discharged out of the fuel cell gas supply diffusion layer 42h more efficiently. Further, the fuel cell gas can be diffused more uniformly downstream of the gas pressure equalizing groove 56.
［変形例９］
　図１６は、変形例９に係る燃料電池用ガス供給拡散層４２ｉの平面構造を説明するために示す図である。 [Modification 9]
FIG. 16 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42i according to Modification 9.
　変形例９に係る燃料電池用ガス供給拡散層４２ｉは、基本的には変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の構成を有するが、バイパス用溝をさらに有する点で変形例２に係る燃料電池用ガス供給拡散層４２ｂの場合と異なる。すなわち、図１６に示すように、変形例９に係る燃料電池用ガス供給拡散層４２ｉにおいては、多孔質体層４０は、多孔質体層４０の一方の面に、燃料電池用ガスの流入側から中央部まで延びたバイパス用溝５９（流入用のバイパス用溝５９Ａ）をさらに有している。また、変形例９に係る燃料電池用ガス供給拡散層４２ｉにおいては、多孔質体層４０は、中央部から前記燃料電池用ガスの流出側まで延びたバイパス用溝５９（流出用のバイパス用溝５９Ｂ）をさらに有している。 The fuel cell gas supply diffusion layer 42i according to the modification 9 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but is further modified in that it further includes a bypass groove. This is different from the case of the fuel cell gas supply diffusion layer 42b according to No. 2. That is, as shown in FIG. 16, in the fuel cell gas supply diffusion layer 42i according to the modified example 9, the porous body layer 40 is disposed on one surface of the porous body layer 40 on the inflow side of the fuel cell gas. Further, a bypass groove 59 (inflow bypass groove 59A) extending from the center to the center is further provided. In the fuel cell gas supply diffusion layer 42i according to the modified example 9, the porous body layer 40 includes a bypass groove 59 (outflow bypass groove) extending from the central portion to the outflow side of the fuel cell gas. 59B).
　各バイパス用溝５９（５９Ａ，５９Ｂ）は、細い矩形状の部分が組み合わされた溝である。各バイパス用溝５９（５９Ａ，５９Ｂ）は、連通する流入側溝５１又は流出側溝５２と同じ深さで形成されている。流入用のバイパス用溝５９Ａは、送り溝部分５９１Ａと幅広げ溝部分５９２Ａと複数の分岐溝部分５９３Ａとが組み合わされて形成されている。送り溝部分５９１Ａは、流入側が流入側溝５１のＸ方向における一方の端部付近に繋がり、流入側溝５１から多孔質体層４０の中央部までＹ方向に延びている。幅広げ溝部分５９２Ａは、送り溝部分５９１Ａの先端側からＸ方向に延びている。分岐溝部分５９３Ａは、孤立穴５５ｉの連続パターン形状と対応するように複数、幅広げ溝部分５９２Ａから短くＹ方向流出側に延びている。流出用のバイパス用溝５９Ｂは、送り溝部分５９１Ｂと幅広げ溝部分５９２Ｂと複数の分岐溝部分５９３Ｂとが組み合わされて形成されている。送り溝部分５９１Ｂは、流出側が流出側溝５２のＸ方向における他方の端部付近に繋がり、流出側溝５２から多孔質体層４０の中央部までＹ方向に延びている。幅広げ溝部分５９２Ｂは、送り溝部分５９１Ｂの先端側からＸ方向に延びている。分岐溝部分５９３Ｂは、孤立穴５５ｉの連続パターン形状と対応するように複数、幅広げ溝部分５９２Ｂから短くＹ方向流入側に延びている。流入用のバイパス用溝５９Ａにおける幅広げ溝部分５９２Ａは、流出用のバイパス用溝５９Ｂにおける幅広げ溝部分５９２Ｂよりも流出側に配置されている。流入用のバイパス用溝５９Ａにおける幅広げ溝部分５９２Ａは、流出用のバイパス用溝５９Ｂにおける送り溝部分５９１Ｂと交差しない程度でＸ方向に広がっている。流出用のバイパス用溝５９Ｂにおける幅広げ溝部分５９２Ｂは、流入用のバイパス用溝５９Ａにおける送り溝部分５９１Ａと交差しない程度でＸ方向に広がっている。このように構成することにより、流入側溝５１と幅広げ溝部分５９２Ｂの間の第１のブロックと、流出側溝５２と幅広げ溝部分５９２Ｂの間の第２のブロックとを構成している。燃料電池用ガスは、第１のブロックと第２のブロックとに分かれて流れる。したがって、両ブロックの両方を通過する燃料電池用ガスはほぼ０である。本変形例においては、このブロック内、すなわち流入側溝５１と幅広げ溝部分５９２Ｂ、あるいは流出側溝５２と幅広げ溝部分５９２Ｂに挟まれた範囲（所望の範囲）ごとに孤立穴５５ｉを配置している。このとき孤立穴５５ｉの大きさや形状、分散配置の配置規則を、個別に代えて配置してもよい。 Each bypass groove 59 (59A, 59B) is a groove in which thin rectangular portions are combined. Each bypass groove 59 (59A, 59B) is formed with the same depth as the inflow side groove 51 or the outflow side groove 52 which communicates. The inflow bypass groove 59A is formed by combining a feed groove portion 591A, a widening groove portion 592A, and a plurality of branch groove portions 593A. The inflow side of the feed groove portion 591A is connected to the vicinity of one end portion in the X direction of the inflow side groove 51, and extends from the inflow side groove 51 to the center of the porous body layer 40 in the Y direction. The widening groove portion 592A extends in the X direction from the distal end side of the feed groove portion 591A. A plurality of branch groove portions 593A extend from the widened groove portion 592A to the outflow side in the Y direction so as to correspond to the continuous pattern shape of the isolated holes 55i. The outflow bypass groove 59B is formed by combining a feed groove portion 591B, a widening groove portion 592B, and a plurality of branch groove portions 593B. The feed groove portion 591 </ b> B is connected to the vicinity of the other end portion in the X direction of the outflow side groove 52 on the outflow side, and extends in the Y direction from the outflow side groove 52 to the center of the porous body layer 40. The widening groove portion 592B extends in the X direction from the leading end side of the feed groove portion 591B. A plurality of branch groove portions 593B extend from the widened groove portion 592B to the inflow side in the Y direction so as to correspond to the continuous pattern shape of the isolated holes 55i. The widening groove portion 592A in the inflow bypass groove 59A is disposed on the outflow side of the widening groove portion 592B in the outflow bypass groove 59B. The widening groove portion 592A in the inflow bypass groove 59A extends in the X direction to the extent that it does not intersect the feed groove portion 591B in the outflow bypass groove 59B. The widening groove portion 592B in the outflow bypass groove 59B expands in the X direction to the extent that it does not intersect the feed groove portion 591A in the inflow bypass groove 59A. By comprising in this way, the 1st block between the inflow side groove | channel 51 and the widening groove part 592B and the 2nd block between the outflow side groove | channel 52 and the widening groove part 592B are comprised. The fuel cell gas flows separately into a first block and a second block. Therefore, the fuel cell gas passing through both blocks is almost zero. In this modification, an isolated hole 55i is arranged in this block, that is, for each range (desired range) sandwiched between the inflow side groove 51 and the widening groove portion 592B, or between the outflow side groove 52 and the widening groove portion 592B. Yes. At this time, the size and shape of the isolated holes 55i and the arrangement rule of the distributed arrangement may be arranged separately.
　変形例９に係る燃料電池用ガス供給拡散層４２ｉによれば、変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の効果が得られるのに加えて、以下の効果が得られる。すなわち、多孔質体層４０は、燃料電池用ガスの流入側から中央部まで延びたバイパス用溝５９（流入用のバイパス用溝５９Ａ）を有していることで、中央部よりも上流で減ってしまった燃料電池用ガスが中央部で補給されるため、中央部よりも下流の発電効率の低下を抑えることができる。また、多孔質体層４０は、中央部から前記燃料電池用ガスの流出側まで延びたバイパス用溝５９（流出用のバイパス用溝５９Ｂ）を有していることで、中央部よりも上流で発電時に膜電極接合体８１で生成した水蒸気または凝集水が中央部から効率よく排出されるため、中央部よりも下流の発電効率の低下を抑えることができる。 According to the fuel cell gas supply diffusion layer 42i according to the modified example 9, in addition to the same effects as the fuel cell gas supply diffusion layer 42b according to the modified example 2, the following effects can be obtained. That is, the porous body layer 40 has a bypass groove 59 (an inflow bypass groove 59A) extending from the fuel cell gas inflow side to the center portion, so that the porous body layer 40 decreases upstream from the center portion. Since the fuel cell gas that has been supplied is replenished in the central portion, it is possible to suppress a decrease in power generation efficiency downstream from the central portion. Further, the porous body layer 40 has a bypass groove 59 (outflow bypass groove 59B) extending from the central portion to the outflow side of the fuel cell gas, so that it is upstream of the central portion. Since water vapor or condensed water generated in the membrane electrode assembly 81 during power generation is efficiently discharged from the central portion, it is possible to suppress a decrease in power generation efficiency downstream from the central portion.
　なお、変形例１～９に係る燃料電池用ガス供給拡散層４２ａ～４２ｉにおいては、一の孤立穴５５１ａ～５５１ｉ（変形例８では一の孤立穴５５１ｈ１，５５１ｈ２）と第１近接孤立穴５５２ａ～５５２ｉ（変形例８では第１近接孤立穴５５２ｈ１，５５２ｈ２）の第１間隔Ｌ１（変形例８では第１間隔Ｌ１１，Ｌ１２）と、一の孤立穴５５１ａ～５５１ｉと第２近接孤立穴５５３ａ～５５３ｉ（変形例８では第２近接孤立穴５５３ｈ１，５５３ｈ２）の第２間隔Ｌ２（変形例８では第２間隔Ｌ１２，Ｌ２２）とは、実施形態の場合と同様に、「Ｌ２≦Ｌ１」及び「Ｌ１＜２×Ｌ２」を満たす。 In the fuel cell gas supply diffusion layers 42a to 42i according to the first to ninth modifications, one isolated hole 551a to 551i (one isolated hole 551h1, 551h2 in the modified example 8) and the first adjacent isolated hole 552a to 552i (first proximity isolated holes 552h1 and 552h2 in the modified example 8), the first interval L1 (first intervals L11 and L12 in the modified example 8), one isolated hole 551a to 551i and the second adjacent isolated hole 553a to 553i. The second interval L2 (the second intervals L12 and L22 in the modified example 8) of the second adjacent isolated holes 553h1 and 553h2 in the modified example 8 is “L2 ≦ L1” and “L1” as in the case of the embodiment. <2 × L2 ”is satisfied.
　また、図１０（変形例３）及び図１１（変形例４）には、一の孤立穴５５１ｃ，５５１ｄから下流側に位置する孤立穴のうち、一の孤立穴５５１ｃ，５５１ｄからＸ方向に沿った距離が三番目に短い、又は第２近接孤立穴５５３ｃ，５５３ｄと同等で二番目に短い孤立穴（すなわち孤立穴５５１ｃ，５５１ｄの重心位置と近接する孤立穴の重心位置とを結ぶベクトルのＸ方向成分の絶対値が三番目に小さい、又は他の孤立穴と同等に二番目に小さい孤立穴）が第３近接孤立穴５５４ｃ，５５４ｄとして描かれている。一の孤立穴５５１ｃ，５５１ｄと第３近接孤立穴５５４ｃ，５５４ｄとの間隔は、特に限定するものではないが、より広く拡散させるように、第１間隔Ｌ１よりも短くすることが好ましい。 Further, in FIG. 10 (Modification 3) and FIG. 11 (Modification 4), among the isolated holes located downstream from the one isolated hole 551c, 551d, the one isolated hole 551c, 551d extends along the X direction. The third shortest distance or the second shortest isolated hole equivalent to the second adjacent isolated hole 553c, 553d (that is, the vector X connecting the centroid position of the isolated hole 551c, 551d and the centroid position of the adjacent isolated hole) An isolated hole whose absolute value of the direction component is the third smallest or the second smallest isolated hole equivalent to other isolated holes) is depicted as third adjacent isolated holes 554c and 554d. The distance between the one isolated hole 551c, 551d and the third adjacent isolated hole 554c, 554d is not particularly limited, but is preferably shorter than the first distance L1 so as to diffuse more widely.
［変形例１０］
　図１７は、変形例１０に係る燃料電池用ガス供給拡散層４２ｊの平面構造を説明するために示す図である。図１８は、図１７におけるＥ－Ｅ線に沿った断面図である。 [Modification 10]
FIG. 17 is a view for explaining the planar structure of the fuel cell gas supply diffusion layer 42j according to Modification 10. 18 is a cross-sectional view taken along line EE in FIG.
　変形例１０に係る燃料電池用ガス供給拡散層４２ｊは、基本的には変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の構成を有するが、孤立穴の底形状が変形例２に係る燃料電池用ガス供給拡散層４２ｂの場合と異なる。すなわち、図１８に示すように、変形例１０に係る燃料電池用ガス供給拡散層４２ｊにおいては、孤立穴として各前記孤立穴の底面が下流側にいくに従って深くなるように傾斜している孤立穴５５ｊを用いている。なお、変形例１０においては、その平面視において長方形の孤立穴５５ｊを用いている例を示しているが、このとき孤立穴５５ｊの大きさや形状、分散配置の配置規則を他の変形例などのように任意に代えてもよい。 The fuel cell gas supply diffusion layer 42j according to the modification 10 has basically the same configuration as the fuel cell gas supply diffusion layer 42b according to the modification 2, but the bottom shape of the isolated hole is the modification 2. This is different from the fuel cell gas supply diffusion layer 42b. That is, as shown in FIG. 18, in the fuel cell gas supply diffusion layer 42j according to the modified example 10, the isolated holes are inclined so that the bottom surfaces of the isolated holes become deeper as they go downstream as isolated holes. 55j is used. In the modification 10, an example in which the rectangular isolated holes 55j are used in the plan view is shown, but at this time, the size and shape of the isolated holes 55j and the arrangement rule of the distributed arrangement are changed to other modified examples. As such, it may be arbitrarily changed.
　変形例１０に係る燃料電池用ガス供給拡散層４２ｊによれば、変形例２に係る燃料電池用ガス供給拡散層４２ｂと同様の効果が得られるのに加えて、各孤立穴の底面が下流側にいくに従って深くなるように傾斜していることから、各孤立穴５５ｊ内を流れる燃料電池用ガスの流れは、膜電極接合体８１に向かうベクトルを含むようになる。このため、孤立穴５５ｊから伏流する燃料電池用ガスがより膜電極接合体８１に向かうこととなり、より多くの燃料電池用ガスを膜電極接合体８１に供給することができるという効果も得られる。 According to the fuel cell gas supply diffusion layer 42j according to the modified example 10, in addition to obtaining the same effect as the fuel cell gas supply diffusion layer 42b according to the modified example 2, the bottom surface of each isolated hole is located on the downstream side. Therefore, the flow of the fuel cell gas flowing in each isolated hole 55j includes a vector directed to the membrane electrode assembly 81. For this reason, the fuel cell gas flowing down from the isolated hole 55j is further directed to the membrane electrode assembly 81, and an effect that more fuel cell gas can be supplied to the membrane electrode assembly 81 is also obtained.
［変形例１１］
　図１９は、変形例１１に係る燃料電池用ガス供給拡散層４２ｋの断面図である。図５の場合と同様に、膜電極接合体８１が接合された状態の燃料電池用セパレータ２３ｋを示している。上記した実施形態においては、燃料電池用ガス供給拡散層として、一方の面に複数の孤立穴５５が形成された多孔質体層４０を備える燃料電池用ガス供給拡散層４２を用いたが（図５参照。）、本発明はこれに限定されるものではない。図１９に示すように、一方の面に複数の孤立穴５５が形成された多孔質体層４０と、当該多孔質体層４０の他方の面に配設されたマイクロポーラスレイヤ４４とを備える燃料電池用ガス供給拡散層を用いこともできる。このような構成とした場合には、マイクロポーラスレイヤを備えない膜電極接合体を用いて燃料電池用セパレータを構成することができるようになる。 [Modification 11]
FIG. 19 is a cross-sectional view of a fuel cell gas supply diffusion layer 42k according to Modification 11. As in the case of FIG. 5, the fuel cell separator 23 k in a state where the membrane electrode assembly 81 is joined is shown. In the embodiment described above, the fuel cell gas supply diffusion layer 42 including the porous body layer 40 having a plurality of isolated holes 55 formed on one surface is used as the fuel cell gas supply diffusion layer (see FIG. 5), the present invention is not limited to this. As shown in FIG. 19, a fuel including a porous body layer 40 having a plurality of isolated holes 55 formed on one surface and a microporous layer 44 disposed on the other surface of the porous body layer 40. A battery gas supply diffusion layer can also be used. In such a configuration, a fuel cell separator can be configured using a membrane electrode assembly that does not include a microporous layer.
　以上、本発明の燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックを、図示の実施の形態に基づいて説明したが、本発明は上記の各実施形態に限られるものではなく、本発明の要旨を逸脱しない範囲で種々変形実施可能となるものである。 The fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to the above embodiments. Various modifications can be made without departing from the scope of the present invention.
［１］上記した実施形態においては、孤立穴として、多孔質体層４０（又は孤立穴５５）の表面における孤立穴の幅と、孤立穴５５の底におけるガス流路用溝の幅とが等しく、断面が長方形状の孤立穴５５を用いたが（図５及び図７参照。）、本発明はこれに限定されるものではない。溝の底が表面よりも狭い断面三角形状の孤立穴を用いてもよいし、溝の底が表面よりも狭い断面半円形状の孤立穴を用いてもよいし、その他の形状の孤立穴を用いてもよい。 [1] In the above-described embodiment, as the isolated hole, the width of the isolated hole on the surface of the porous body layer 40 (or the isolated hole 55) is equal to the width of the gas channel groove at the bottom of the isolated hole 55. Although the isolated hole 55 having a rectangular cross section is used (see FIGS. 5 and 7), the present invention is not limited to this. An isolated hole with a triangular cross section narrower than the surface of the groove may be used, or an isolated hole with a semicircular cross section with a bottom of the groove narrower than the surface may be used. It may be used.
［２］上記した実施形態においては、ガス遮蔽板として、金属板３０を用いたが、本発明はこれに限定されるものではない。金属板３０以外の、ガスを遮蔽する性質をもった材料からなる板（例えば、セラミックス板、樹脂板）を用いてもよい。 [2] In the embodiment described above, the metal plate 30 is used as the gas shielding plate, but the present invention is not limited to this. A plate (for example, a ceramic plate or a resin plate) made of a material having a property of shielding gas other than the metal plate 30 may be used.
［３］上記各変形例は、各変形例に記載の特徴を、実施形態に係る燃料電池用ガス供給拡散層４２、燃料電池用セパレータ２３及び燃料電池セルスタック２０に適用したものであるが、各変形例に記載の特徴は、これに限らず、本発明の燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックの全般に適用可能である。例えば、各変形例に記載の特徴は、タイプＣＡの燃料電池用ガス供給拡散層２１、タイプＡの燃料電池用ガス供給拡散層２２、タイプＣＷの燃料電池用ガス供給拡散層２４及びタイプＡＷの燃料電池用ガス供給拡散層２５、並びに、これらの燃料電池用ガス供給拡散層を備えた燃料電池用セパレータ及び燃料電池セルスタックにも適用可能である。 [3] In each of the above modifications, the characteristics described in each modification are applied to the fuel cell gas supply diffusion layer 42, the fuel cell separator 23, and the fuel cell stack 20 according to the embodiment. The features described in each modification are not limited to this, and can be applied to the fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack of the present invention. For example, the characteristics described in each of the modified examples are that the gas supply diffusion layer 21 for fuel cells of type CA, the gas supply diffusion layer 22 for fuel cells of type A, the gas supply diffusion layer 24 for fuel cells of type CW, and the type AW The present invention is also applicable to the fuel cell gas supply diffusion layer 25, and the fuel cell separator and fuel cell stack provided with these fuel cell gas supply diffusion layers.
［４］上記各変形例は、上記実施形態又は上記他の変形例に対して、特徴のある一部のみを変形して記載しているが、適宜、各一部を組みあわせて変形することも可能である。例えば、変形例５～９を組み合わせて、孤立穴５５を流出側に向かうに従って細く、短く、Ｘ方向に隣接する孤立穴５５同志の間隔が狭くなるように形成するとともに、ガス圧均等化用溝５６及びバイパス用溝５９が形成された燃料電池セパレータ２３を構成してもよい。 [4] Although each of the above-described modifications is described by modifying only some of the features of the above-described embodiment or the above-described other modifications, the modifications may be appropriately combined and modified. Is also possible. For example, by combining the modified examples 5 to 9, the isolated hole 55 is formed so as to become narrower and shorter toward the outflow side, and the interval between the isolated holes 55 adjacent in the X direction becomes narrower, and the gas pressure equalizing groove 56 and the fuel cell separator 23 in which the bypass groove 59 is formed may be configured.
［５］上記実施形態及び上記各変形例は、ある程度同形状の孤立穴５５がＸ方向に一定のピッチで配置されるものとして説明したがこれに限定されるものではない。例えば、複数種類の全く形状の異なる孤立穴を組み合わせて構成されていてもよいし、Ｘ方向のピッチが変化するように配置されていても良い。 [5] In the above embodiment and each of the modifications, it has been described that the isolated holes 55 having the same shape to some extent are arranged at a constant pitch in the X direction. For example, a plurality of types of isolated holes having completely different shapes may be combined, or may be arranged so that the pitch in the X direction changes.
［６］上記実施形態及び上記変形例１～１０は、孤立穴や各溝の深さが同じであるものとして説明したがこれに限定されるものではない。例えば、孤立穴や溝の深さは、孤立穴や溝ごとに異なっていてもよいし、孤立穴や溝のなかで変動していてもよい。 [6] Although the above embodiment and the above modifications 1 to 10 have been described assuming that the depths of the isolated holes and the grooves are the same, the present invention is not limited to this. For example, the depth of the isolated hole or groove may be different for each isolated hole or groove, or may vary within the isolated hole or groove.
［７］上記各変形例は、各変形例に記載の特徴を、実施形態に係る燃料電池用ガス供給拡散層４２、燃料電池用セパレータ２３及び燃料電池セルスタック２０に適用したものであるが、各変形例に記載の特徴は、これに限らず、本発明の燃料電池用ガス供給拡散層、燃料電池用セパレータ及び燃料電池セルスタックの全般に適用可能である。例えば、各変形例に記載の特徴は、タイプＣＡの燃料電池用ガス供給拡散層２１、タイプＡの燃料電池用ガス供給拡散層２２、タイプＣＷの燃料電池用ガス供給拡散層２４及びタイプＡＷの燃料電池用ガス供給拡散層２５、並びに、これらの燃料電池用ガス供給拡散層を備えた燃料電池用セパレータ及び燃料電池セルスタックにも適用可能である。 [7] In each of the above modifications, the features described in each modification are applied to the fuel cell gas supply diffusion layer 42, the fuel cell separator 23, and the fuel cell stack 20 according to the embodiment. The features described in each modification are not limited to this, and can be applied to the fuel cell gas supply diffusion layer, the fuel cell separator, and the fuel cell stack of the present invention. For example, the characteristics described in each of the modified examples are that the gas supply diffusion layer 21 for fuel cells of type CA, the gas supply diffusion layer 22 for fuel cells of type A, the gas supply diffusion layer 24 for fuel cells of type CW, and the type AW The present invention is also applicable to the fuel cell gas supply diffusion layer 25, and the fuel cell separator and fuel cell stack provided with these fuel cell gas supply diffusion layers.
２０　燃料電池セルスタック
２１，２２，２３，２４，２５　燃料電池用セパレータ
２７Ａ，２７Ｂ　集電板
２８Ａ，２８Ｂ　絶縁シート
３０　金属板
３２　緻密枠
３３　ガスケット
３３Ａ　ガスケット用溝
４０　多孔質体層
４１　燃料電池用ガス供給拡散層（アノードガス供給拡散層）
４２、４２ａ～４２ｋ　燃料電池用ガス供給拡散層（カソードガス供給拡散層）
４３　ガス拡散部
４４　マイクロポーラスレイヤ
５１　流入側溝
５２　流出側溝
５５、５５ａ～５５ｊ　孤立穴
５６　ガス圧均等化用溝
５７　流入通路
５８　流出通路
５９　バイパス用溝
５９Ａ　流入用のバイパス用溝
５９Ｂ　流出用のバイパス用溝
６１Ａ　アノードガス流入口
６１Ｂ　アノードガス流出口
６２Ａ　カソードガス流入口
６２Ｂ　カソードガス流出口
６３Ａ　冷却水流入口
６３Ｂ　冷却水流出口
７４　締め付け・バネサポート
７５、７６　エンドプレート
８０　セル構造体
８１　膜電極接合体
８１Ａ　枠（フレーム）
８２　電解質膜
８３　マイクロポーラスレイヤ
８５　触媒層
５５１，５５１ａ～５５１ｉ　一の孤立穴
５５２，５５２ａ～５５２ｉ　第１近接孤立穴
５５３，５５３ａ～５５３ｉ　第２近接孤立穴
Ｌ１，Ｌ１１，Ｌ２１　第１間隔
Ｌ２，Ｌ１２，Ｌ２２　第２間隔
Ｗ１～Ｗ３　孤立穴のＹ方向の長さ（幅）
Ｄ１～Ｄ３　孤立穴のＸ方向の長さ
Ｐ１，Ｐ２　孤立穴同士のＸ方向の間隔 20 Fuel cell stack 21, 22, 23, 24, 25 Separator 27A, 27B for fuel cell Insulation sheet 30A, 28B Insulation sheet 30 Metal plate 32 Dense frame 33 Gasket 33A Gasket groove 40 Porous body layer 41 For fuel cell Gas supply diffusion layer (anode gas supply diffusion layer)
42, 42a to 42k Gas supply diffusion layer for fuel cell (cathode gas supply diffusion layer)
43 Gas diffusion portion 44 Microporous layer 51 Inflow side groove 52 Outflow side grooves 55, 55a to 55j Isolated hole 56 Gas pressure equalization groove 57 Inflow path 58 Outflow path 59 Bypass groove 59A Inflow bypass groove 59B Outflow bypass Groove 61A Anode gas inlet 61B Anode gas outlet 62A Cathode gas inlet 62B Cathode gas outlet 63A Cooling water inlet 63B Cooling water outlet 74 Tightening / spring support 75, 76 End plate 80 Cell structure 81 Membrane electrode assembly 81A Frame
82 Electrolyte membrane 83 Microporous layer 85 Catalyst layers 551, 551a to 551i One isolated hole 552, 552a to 552i First adjacent isolated hole 553, 553a to 553i Second adjacent isolated hole L1, L11, L21 First interval L2, L12 , L22 Second interval W1-W3 Length (width) of isolated hole in Y direction
D1 to D3 Length of isolated holes in the X direction P1, P2 Distance between isolated holes in the X direction

Claims (18)

  1. 　使用時に上流側から下流側に向かって燃料電池用ガスが流れる燃料電池用ガス供給拡散層であって、
    　前記燃料電池用ガスを透過、拡散し、導電性を有する多孔質体層を備え、
    　前記多孔質体層は、多孔質体からなるガス拡散部と、前記多孔質体層の一方の面に分散して配置された複数の孤立穴とを有し、
    　前記孤立穴の各々は、互いに孤立して前記多孔質体層に形成され、開口部を除く周囲が前記ガス拡散部に囲まれ、多孔質体の底を有する凹部からなることを特徴とする燃料電池用ガス供給拡散層。     A fuel cell gas supply diffusion layer in which fuel cell gas flows from the upstream side toward the downstream side during use,
    Permeating and diffusing the fuel cell gas, comprising a porous layer having conductivity,
    The porous body layer has a gas diffusion portion made of a porous body, and a plurality of isolated holes arranged dispersed on one surface of the porous body layer,
    Each of the isolated holes is formed in the porous body layer so as to be isolated from each other, the periphery except for the opening is surrounded by the gas diffusion portion, and the fuel has a bottom having a porous body Battery gas supply diffusion layer.
  2. 　請求項１に記載の燃料電池用ガス供給拡散層において、
    　前記上流側から前記下流側に向かう方向をＹ方向とし、平面的に前記Ｙ方向に直交する幅方向をＸ方向とし、前記複数の孤立穴のうちの一の孤立穴から前記下流側に位置する孤立穴のうち、前記一の孤立穴から前記Ｘ方向に沿った距離が最も短い孤立穴を第１近接孤立穴とし、前記一の孤立穴から前記Ｘ方向に沿った距離が二番目に短い孤立穴を第２近接孤立穴としたとき、前記一の孤立穴と前記第１近接孤立穴の第１間隔Ｌ１と、前記一の孤立穴と前記第２近接孤立穴の第２間隔Ｌ２とは、「Ｌ２≦Ｌ１」の関係を満たすことを特徴とする燃料電池用ガス供給拡散層。     In the fuel cell gas supply diffusion layer according to claim 1,
    A direction from the upstream side to the downstream side is a Y direction, a width direction orthogonal to the Y direction in a plane is an X direction, and is located on the downstream side from one of the plurality of isolated holes. Among the isolated holes, the isolated hole having the shortest distance along the X direction from the one isolated hole is defined as a first adjacent isolated hole, and the isolated distance along the X direction from the one isolated hole is the second shortest isolated hole. When the hole is a second adjacent isolated hole, the first interval L1 between the one isolated hole and the first adjacent isolated hole, and the second interval L2 between the one isolated hole and the second adjacent isolated hole are: A fuel cell gas supply diffusion layer satisfying a relationship of “L2 ≦ L1”.
  3. 　請求項２に記載の燃料電池用ガス供給拡散層において、
    　前記第１間隔Ｌ１と前記第２間隔Ｌ２とは、「Ｌ１＜２×Ｌ２」の関係を満たすことを特徴とする燃料電池用ガス供給拡散層。     The fuel cell gas supply diffusion layer according to claim 2,
    The gas supply diffusion layer for a fuel cell, wherein the first interval L1 and the second interval L2 satisfy a relationship of “L1 <2 × L2”.
  4. 　請求項１～３のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記多孔質体層の一方の面に形成された孤立穴のうち、外側の孤立穴の重心位置を結んだ閉曲線に囲まれる範囲の面積をＳ１とし、前記複数の孤立穴の合計面積をＳ２としたとき、「０．９×Ｓ１≧Ｓ２≧０．１×Ｓ１」の関係を満たすことを特徴とする燃料電池用ガス供給拡散層。     In the fuel cell gas supply diffusion layer according to any one of claims 1 to 3,
    Of the isolated holes formed on one surface of the porous body layer, an area in a range surrounded by a closed curve connecting the center of gravity positions of the outer isolated holes is S1, and the total area of the plurality of isolated holes is S2. The fuel cell gas supply diffusion layer satisfies the relationship of “0.9 × S1 ≧ S2 ≧ 0.1 × S1”.
  5. 　請求項１～４のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記孤立穴においては、前記多孔質体が露出していることを特徴とする請求項１～３のいずれかに記載の燃料電池用ガス供給拡散層。     In the fuel cell gas supply diffusion layer according to any one of claims 1 to 4,
    The gas supply diffusion layer for a fuel cell according to any one of claims 1 to 3, wherein the porous body is exposed in the isolated hole.
  6. 　請求項１～５のいずれかに記載の燃料電池用ガス供給拡散層において、
    　各前記孤立穴の底面は、下流側にいくに従って深くなるように傾斜していることを特徴とする燃料電池用ガス供給拡散層。     In the gas supply diffusion layer for a fuel cell according to any one of claims 1 to 5,
    A gas supply diffusion layer for a fuel cell, wherein a bottom surface of each of the isolated holes is inclined so as to become deeper toward a downstream side.
  7. 　請求項１～６に記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴の少なくとも一部の孤立穴は、幅が変化していることを特徴とする燃料電池用ガス供給拡散層。     The fuel cell gas supply diffusion layer according to any one of claims 1 to 6,
    A gas supply diffusion layer for a fuel cell, wherein the width of at least some of the plurality of isolated holes varies.
  8. 　請求項１～６に記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴の少なくとも一部の孤立穴は、幅が一定であることを特徴とする燃料電池用ガス供給拡散層。     The fuel cell gas supply diffusion layer according to any one of claims 1 to 6,
    A gas supply diffusion layer for a fuel cell, wherein at least some of the plurality of isolated holes have a constant width.
  9. 　請求項１～８のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴の少なくとも一部の孤立穴は、斜めの方向に沿って延びている孤立溝であることを特徴とする燃料電池用ガス供給拡散層。     The gas supply diffusion layer for a fuel cell according to any one of claims 1 to 8,
    A gas supply diffusion layer for a fuel cell, wherein at least some of the isolated holes are isolated grooves extending in an oblique direction.
  10. 　請求項１～９のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴の少なくとも一部の孤立穴は、途中で曲がっていることを特徴とする燃料電池用ガス供給拡散層。     The fuel cell gas supply diffusion layer according to any one of claims 1 to 9,
    The gas supply diffusion layer for a fuel cell, wherein at least some of the plurality of isolated holes are bent in the middle.
  11. 　請求項１～１０のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴は、前記下流側にいくに従って平面的に見た面積が段階的に小さくなるように形成されていることを特徴とする燃料電池用ガス供給拡散層。     The gas supply diffusion layer for a fuel cell according to any one of claims 1 to 10,
    The gas supply diffusion layer for a fuel cell, wherein the plurality of isolated holes are formed so that an area seen in a plan view gradually decreases as going to the downstream side.
  12. 　請求項１～１１のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記複数の孤立穴は、前記下流側にいくに従って、幅方向に近接する孤立穴同士の間隔が段階的に狭くなっていることを特徴とする燃料電池用ガス供給拡散層。     The gas supply diffusion layer for a fuel cell according to any one of claims 1 to 11,
    The gas supply diffusion layer for a fuel cell, wherein the plurality of isolated holes are narrowed stepwise from each other in the width direction as they go downstream.
  13. 　請求項１～１２のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記多孔質体層の一方の面に、前記多孔質体層の幅方向一杯に延びた１又は複数のガス圧均等化用溝をさらに有することを特徴とする燃料電池用ガス供給拡散層。     The fuel cell gas supply diffusion layer according to any one of claims 1 to 12,
    The gas supply diffusion layer for a fuel cell, further comprising one or a plurality of gas pressure equalization grooves extending in the width direction of the porous body layer on one surface of the porous body layer.
  14. 　請求項１～１３のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記多孔質体層の一方の面に、少なくとも前記燃料電池用ガスの流入側から中央部まで延びた、又は中央部から前記燃料電池用ガスの流出側まで延びた１又は複数のバイパス用溝をさらに有することを特徴とする燃料電池用ガス供給拡散層。     The gas supply diffusion layer for a fuel cell according to any one of claims 1 to 13,
    One surface of the porous body layer has at least one bypass groove extending from the fuel cell gas inflow side to the center or from the center to the fuel cell gas outflow side. A gas supply diffusion layer for a fuel cell, further comprising:
  15. 　請求項１～１４のいずれかに記載の燃料電池用ガス供給拡散層において、
    　前記燃料電池用ガス供給拡散層が、カソードガス用の燃料電池用ガス供給拡散層であることを特徴とする燃料電池用ガス供給拡散層。     In the fuel cell gas supply diffusion layer according to any one of claims 1 to 14,
    The fuel cell gas supply diffusion layer is a fuel cell gas supply diffusion layer for cathode gas.
  16. 　請求項１５に記載の燃料電池用ガス供給拡散層において、
    　前記カソードガスが空気であることを特徴とする燃料電池用ガス供給拡散層。     The gas supply diffusion layer for a fuel cell according to claim 15,
    A gas supply diffusion layer for a fuel cell, wherein the cathode gas is air.
  17. 　ガス遮蔽板と、前記ガス遮蔽板の少なくとも一方の面に配設された燃料電池用ガス供給拡散層とを備える燃料電池用セパレータであって、
    　前記燃料電池用ガス供給拡散層は、請求項１～１６のいずれかに記載の燃料電池用ガス供給拡散層であり、
    　前記燃料電池用ガス供給拡散層は、前記複数の孤立穴が前記ガス遮蔽板側に位置するように前記ガス遮蔽板に対して配置されており、
    　前記孤立穴と前記ガス遮蔽板とでガス流路が構成されていることを特徴とする燃料電池用セパレータ。     A fuel cell separator comprising a gas shielding plate and a fuel cell gas supply diffusion layer disposed on at least one surface of the gas shielding plate,
    The gas supply diffusion layer for a fuel cell is the gas supply diffusion layer for a fuel cell according to any one of claims 1 to 16,
    The fuel cell gas supply diffusion layer is disposed with respect to the gas shielding plate such that the plurality of isolated holes are located on the gas shielding plate side,
    A fuel cell separator comprising a gas flow path formed by the isolated hole and the gas shielding plate.
  18. 　燃料電池用セパレータと、膜電極接合体とが積層されてなる燃料電池セルスタックであって、
    　前記燃料電池用セパレータは、請求項１７に記載の燃料電池用セパレータであり、
    　前記燃料電池用セパレータと前記膜電極接合体とは、前記燃料電池用ガス供給拡散層の前記複数の孤立穴が形成されていない側の面に前記膜電極接合体が位置する位置関係で積層されていることを特徴とする燃料電池セルスタック。     A fuel cell stack in which a fuel cell separator and a membrane electrode assembly are laminated,
    The fuel cell separator is the fuel cell separator according to claim 17,
    The fuel cell separator and the membrane electrode assembly are stacked in such a positional relationship that the membrane electrode assembly is positioned on the surface of the fuel cell gas supply diffusion layer where the plurality of isolated holes are not formed. A fuel cell stack characterized by comprising:
PCT/JP2018/023031 2018-06-15 2018-06-15 Gas supply diffusion layer for fuel cell, separator for fuel cell, and fuel cell stack WO2019239605A1 (en)

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WO2021171793A1 (en) 2020-02-25 2021-09-02 国立大学法人山梨大学 Gas diffusion member, gas diffusion unit, and fuel cell

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JP2013020843A (en) * 2011-07-12 2013-01-31 Mitsubishi Rayon Co Ltd Gas diffusion electrode and fuel cell using the same
WO2015072584A1 (en) * 2013-11-18 2015-05-21 国立大学法人山梨大学 Separator and cell stack for fuel cell
JP2017016942A (en) * 2015-07-03 2017-01-19 国立大学法人山梨大学 Separator for fuel battery, cell structure and cell stack

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JP2013020843A (en) * 2011-07-12 2013-01-31 Mitsubishi Rayon Co Ltd Gas diffusion electrode and fuel cell using the same
WO2015072584A1 (en) * 2013-11-18 2015-05-21 国立大学法人山梨大学 Separator and cell stack for fuel cell
JP2017016942A (en) * 2015-07-03 2017-01-19 国立大学法人山梨大学 Separator for fuel battery, cell structure and cell stack

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021171793A1 (en) 2020-02-25 2021-09-02 国立大学法人山梨大学 Gas diffusion member, gas diffusion unit, and fuel cell
KR20220145354A (en) 2020-02-25 2022-10-28 고쿠리츠다이가쿠호징 야마나시다이가쿠 Gas diffusion member, gas diffusion unit, fuel cell

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