Fuel cell

Abstract

The present disclosure relates to a fuel cell. The fuel cell includes a membrane electrode assembly including a first catalyst layer, a second catalyst layer, and an electrolyte membrane disposed between the first catalyst layer and the second catalyst layer; a first gas diffusion layer laminated on the first catalyst layer; a second gas diffusion layer laminated on the second catalyst layer; a support disposed on at least a portion of a periphery around the membrane electrode assembly; and a tab disposed between the first gas diffusion layer and the membrane electrode assembly to bridge the support and at least one end portion of the electrolyte membrane and the first catalyst layer, wherein the tab includes a tab portion as a layer on one side of the membrane electrode assembly and a penetration portion laminated on the tab portion and penetrating into the first gas diffusion layer.

Description

Technical Field

[0001] This disclosure relates to a fuel cell. Background Technology

[0002] Japanese Unexamined Patent Application Publication Nos. 2021-057200 (JP 2021-057200 A), 2021-057209 (JP 2021-057209 A), and 2020-145026 (JP 2020-145026 A) disclose the use of adhesives to bond frame members (resin frame members, support frames) and electrode laminates. Japanese Unexamined Patent Application Publication No. 2021-144854 (JP 2021-144854 A) discloses a structure in which an adhesive and a cover sheet are arranged to bridge the support frame and the membrane electrode assembly, and a gas diffusion layer is laminated onto the cover sheet. Summary of the Invention

[0003] When adhesives are used to directly bond the frame members and electrode laminates as described in JP 2021-057200 A, JP 2021-057209 A, and JP 2020-145026 A, the electrode laminates may be damaged due to thermal expansion or contraction of various components, including the frame members, or external forces. Furthermore, in configurations where cover sheets are arranged as described in JP2021-144854A, damage to the membrane electrode assembly or gas diffusion layer has been observed, and this damage may lead to leakage of reactive gases.

[0004] This disclosure provides a fuel cell in which damage to the membrane electrode assembly or gas diffusion layer can be reduced when the support and membrane electrode assembly are joined.

[0005] In a cover sheet comprising a sheet portion and a bonding layer that fixes the sheet portion, a space is formed at the end portion of the cover sheet on the membrane electrode assembly side due to the thickness of the cover sheet, and this space can damage the membrane electrode assembly or the gas diffusion layer. The technology disclosed herein achieves this problem through specific means, as detailed below.

[0006] One aspect of this disclosure relates to a fuel cell comprising: a membrane electrode assembly including a first catalyst layer, a second catalyst layer, and an electrolyte membrane disposed between the first catalyst layer and the second catalyst layer; a first gas diffusion layer laminated on the first catalyst layer and having at least a portion of an outer peripheral end disposed to pass through an outer peripheral end of the membrane electrode assembly; a second gas diffusion layer laminated on the second catalyst layer; a support member disposed on at least a portion of the periphery of the membrane electrode assembly; and a cover plate disposed between the first gas diffusion layer and the membrane electrode assembly to bridge the support member with at least one end of the electrolyte membrane and the first catalyst layer, wherein the cover plate includes a sheet portion and a permeation portion, the sheet portion serving as a layer on one side of the membrane electrode assembly, and the permeation portion laminated on the sheet portion and permeating into the first gas diffusion layer.

[0007] In the fuel cell according to the aforementioned scheme, the first gas diffusion layer may include a diffusion member and a microporous layer, the microporous layer being disposed on the surface of the diffusion member on one side of the first catalyst layer, and the permeable portion of the cover sheet being able to pass through the microporous layer and permeate upwards to the diffusion member.

[0008] In the fuel cell according to the aforementioned scheme, the end faces of the support and the end faces of the membrane electrode assembly can be arranged to face each other through a gap.

[0009] According to the scheme described in this disclosure, in the fuel cell, the cover sheet is bonded to the first gas diffusion layer side by a bonding layer, and the bonding layer permeates into the first gas diffusion layer. Therefore, the size of the space formed at the end of the cover sheet on the membrane electrode assembly side can be reduced, and damage to the membrane electrode assembly or the gas diffusion layer can be reduced. Attached Figure Description

[0010] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0011] Figure 1 It is a plan view showing a single-cell power generation unit;

[0012] Figure 2 This is a cross-sectional view showing the layered structure of the power generation section;

[0013] Figure 3 It is a cross-sectional view showing the layered structure of the outer periphery;

[0014] Figure 4 It is shown in the figure. Figure 3 A magnified view of a portion;

[0015] Figure 5This is a diagram illustrating another embodiment;

[0016] Figure 6 This is a diagram illustrating another embodiment;

[0017] Figure 7 It is a diagram illustrating the method of arranging the cover plate; and

[0018] Figure 8 This is a diagram illustrating a fuel cell. Detailed Implementation

[0019] 1. Unitary power generation battery

[0020] Figures 1 to 3 The diagram illustrates a unit cell 10 according to one embodiment. The unit cell 10 is a unit element that generates electricity by supplying hydrogen and oxygen (air), and multiple unit cells 10 are laminated to construct a fuel cell.

[0021] Figure 1 This is a plan view of the unit power generation cell 10. Figure 2 The figure shows the layered structure of the power generation section 11 in the unit power generation cell 10. Figure 3 This is a diagram illustrating the layered structure of the outer periphery 21 in the unit power generation cell 10.

[0022] 1.1 Power Generation Department

[0023] For example, in the power generation section 11 Figure 1 The part enclosed by the dashed line in the middle is the part that helps generate electricity, and there are multiple layers such as Figure 2 The image shows a laminated surface. Figure 2 The diagram shows the layered structure of the power generation section 11 (part of section II-II).

[0024] In the power generation section 11 of the unit power generation cell 10, on both sides where an electrolyte membrane 12 is inserted, the first side is the cathode (oxygen supply side), and the second side is the anode (hydrogen supply side). In the cathode, a cathode catalyst layer 13 (first catalyst layer), a cathode gas diffusion layer 14 (first gas diffusion layer), and a cathode separator 15 (first separator) are laminated sequentially from the electrolyte membrane 12 side. On the other hand, in the anode, an anode catalyst layer 16 (second catalyst layer), an anode gas diffusion layer 17 (second gas diffusion layer), and an anode separator 18 (second separator) are laminated sequentially from the electrolyte membrane 12 side. The laminate including the electrolyte membrane 12, the cathode catalyst layer 13, and the anode catalyst layer 16 is also referred to as a membrane electrode assembly. The thickness of the membrane electrode assembly is typically about 0.4 mm, and the thickness of the unit power generation cell 10 in the power generation section 11 is typically about 1.3 mm.

[0025] Various layers can adopt well-known constructions, and can adopt constructions such as the following.

[0026] 1.1a. Electrolyte membrane

[0027] The electrolyte membrane 12 is a solid polymer membrane that exhibits satisfactory proton conductivity in a wetted state. The electrolyte membrane 12 is formed of, for example, a fluoride ion exchange membrane. For example, carbon-fluoropolymers can be used, and specific examples include perfluoroalkyl sulfonic acid polymers (NAFION (registered trademark)).

[0028] The thickness of the electrolyte membrane 12 is not particularly limited, but is less than 100 μm, preferably less than 50 μm, and more preferably less than 10 μm.

[0029] 1.1b. Cathode catalyst layer

[0030] The cathode catalyst layer 13 is a layer comprising a catalytic metal, wherein the catalytic metal is supported by a support. Examples of catalytic metals include Pt, Pd, Rh, and alloys comprising Pt, Pd, or Rh. Examples of supports include carbon supports, and more specifically, carbon particles formed from glassy carbon, carbon black, activated carbon, coke, natural graphite, artificial graphite, etc.

[0031] 1.1c. Anode catalyst layer

[0032] As in the cathode catalyst layer 13, the anode catalyst layer 16 is also a layer containing a catalytic metal, which is supported by a support. Examples of catalytic metals include Pt, Pd, Rh, and alloys containing Pt, Pd, or Rh. Examples of supports include carbon supports, and more specifically, carbon particles formed from glassy carbon, carbon black, activated carbon, coke, natural graphite, artificial graphite, etc.

[0033] 1.1d. Cathode gas diffusion layer

[0034] In this embodiment, the cathode gas diffusion layer 14 includes a diffusion member 14a and a microporous layer (hereinafter referred to as "MPL") 14b.

[0035] The diffusion member 14a is a layer formed of, for example, a conductive porous body. Specific examples of conductive porous bodies include carbon porous bodies (e.g., carbon paper, carbon cloth, or glassy carbon) and metal porous bodies (metal mesh, metal foam).

[0036] MPL 14b is a coating film applied to the cathode catalyst layer 13 side of the diffusion member 14a. MPL 14b may optionally be hydrophobic or hydrophilic and has a humidity regulating function. As MPL 14b, for example, a layer comprising a hydrophobic resin such as polytetrafluoroethylene (PTFE) and a conductive material such as carbon black as the main components is typically used.

[0037] 1.1e. Anode gas diffusion layer

[0038] The anode gas diffusion layer 17 is a layer formed of, for example, a conductive porous body. Specific examples of conductive porous bodies include carbon porous bodies (e.g., carbon paper, carbon cloth, or glassy carbon) and metal porous bodies (metal mesh, metal foam).

[0039] 1.1f. Cathode separator

[0040] The cathode separator 15 is a component that supplies the reactive gas (air in this embodiment) to the cathode gas diffusion layer 14, and includes a plurality of grooves 15a on its surface facing the cathode gas diffusion layer 14. The grooves serve as channels for the reactive gas. The shape of the grooves is not particularly limited, as long as the reactive gas can be supplied to the cathode gas diffusion layer 14 through the grooves. Examples of groove shapes include a serpentine shape, where the plate-like component is formed in a wavy pattern. In this case, the plate thickness is typically 0.1 mm to 0.2 mm, and the height of the unevenness is typically approximately 0.5 mm.

[0041] When the groove has a serpentine shape, the groove 15b is formed on the side of the cathode separator 15 opposite to the adjacent groove 15a, and the groove 15b serves as a coolant channel.

[0042] Furthermore, in the cathode partition 15, such as Figure 1 As shown, at a location extending outward from the power generation unit 11, air inlet A... 入 Coolant inlet W 入 Hydrogen outlet H 出 Air outlet A is located in the portion at the first end side extending in the direction of grooves 15a and 15b. 出 Coolant outlet W 出 and hydrogen inlet H 入 It is provided in the portion on the second end side in the extending direction of grooves 15a and 15b. Here, groove 15a is connected to air inlet A. 入 and air outlet A 出 Connecting groove 15b with coolant inlet W 入 and coolant outlet W 出 Connected.

[0043] The material used to form the cathode separator 15 can be any material capable of being used as a separator in a single-cell power generation battery, and can be an impermeable conductive material. Examples of such materials include impermeable dense carbon obtained by compression and metal plates obtained by molding.

[0044] 1.1g. Anode separator

[0045] The anode separator 18 is a component that supplies the reactant gas (hydrogen) to the anode gas diffusion layer 17, and includes a plurality of grooves 18a on its surface facing the anode gas diffusion layer 17. The grooves serve as channels for the reactant gas. The shape of the grooves is not particularly limited, as long as the reactant gas can be supplied to the anode gas diffusion layer 17 through the grooves. For example, a serpentine shape can be used in this embodiment. In this case, the sheet thickness is typically 0.1 mm to 0.2 mm, and the unevenness height is typically about 0.4 mm.

[0046] When the groove has a serpentine shape, the groove 18b is formed on the side of the anode diaphragm 18 opposite to the adjacent groove 18a, and the groove 18b serves as a coolant channel.

[0047] Furthermore, in the anode partition 18, such as Figure 1 As shown, at a location extending outward from the power generation unit 11, air inlet A... 入 Coolant inlet W 入 Hydrogen outlet H 出 Air outlet A is located in the portion at the first end side extending in the direction of grooves 18a and 18b. 出 Coolant outlet W 出 and hydrogen inlet H 入 It is located in the portion on the second end side extending in the direction of grooves 18a and 18b. Here, groove 18a is connected to hydrogen inlet H. 入 and hydrogen outlet H 出 Connecting groove 18b with coolant inlet W 入 and coolant outlet W 出 Connected.

[0048] The material used to form the anode separator 18 can be any material that can be used as a separator in a single-cell power generation battery, and can be an impermeable conductive material. Examples of such materials include impermeable dense carbon obtained by compression and metal plates obtained by molding.

[0049] 1.1h. Power generation of the power generation department

[0050] As is well known, the unit power generation battery 10 generates electricity as follows.

[0051] From hydrogen inlet H 入 Hydrogen gas supplied to the groove 18a of the anode partition 18 passes through the anode gas diffusion layer 17 and is decomposed into protons (H+) by the anode catalyst layer 16. + ) and electrons (e - Protons pass through the electrolyte membrane 12, electrons pass through the wires leading to the outside of the unit cell 10, and both protons and electrons reach the cathode catalyst layer 13. The remaining hydrogen gas exits from the hydrogen outlet H. 出 discharge.

[0052] Oxygen (air) enters from air inlet A 入 The gas is supplied to the cathode catalyst layer 13 through the groove 15a of the cathode separator 15 and the cathode gas diffusion layer 14. In the cathode catalyst layer 13, water (H2O) is generated from protons, electrons, and oxygen. The generated water and the remaining air pass through the cathode gas diffusion layer 14, reach the groove 15a of the cathode separator 15, and exit from the air outlet A. 出 discharge.

[0053] In the unit cell 10, the flow of electrons from the anode catalyst layer 16 through the wires leading to the outside of the unit cell 10 is used as an electric current.

[0054] Furthermore, by arranging the cell units 10 adjacent to each other, such that the cathode separator 15 of one cell unit 10 overlaps with the anode separator 18 of another cell unit 10, a coolant channel is formed through the groove 15b of the cathode separator 15 and the groove 18b of the anode separator 18. Coolant flows from the coolant inlet W... 入 The coolant is supplied to the coolant channel, the supplied coolant cools the unit power generation cell 10, and the coolant exits from the coolant outlet W. 出 discharge.

[0055] 1.2.Peripheral part

[0056] The outer periphery 21 is the unit power generation cell 10 in which the battery is located. Figure 1 The outer periphery of the power generation section 11 is surrounded by a dashed line, and multiple layers are as follows: Figure 3 It is laminated as shown. Figure 3 The figure shows the layered structure of the outer periphery 21 (section III-III).

[0057] 1.2a. Structure of the outer periphery

[0058] from Figure 3 As can be seen from this, the outer peripheral portion 21 has the following structure in at least a part of it.

[0059] The electrolyte membrane 12, the anode catalyst layer 16, and the anode gas diffusion layer 17 are laminated such that their end faces are located at substantially the same position, and the end face of the cathode catalyst layer 13 is located in a position recessed (receded) from the end face of the electrolyte membrane 12. Furthermore, the end face of the cathode gas diffusion layer 14 is located in a position protruding (advanced) from the end face of the electrolyte membrane 12 and extends into the plan view of the unit power generation cell 10 (from...). Figure 1 Looking in the middle direction, Figure 3 The position in the view (in the direction indicated by the middle arrow L) that overlaps with support member 23. Support member 23 will be described below.

[0060] Even in the outer peripheral portion 21, the cathode separator 15 and the anode separator 18 are arranged such that the aforementioned layers are inserted as in the power generation section 11. Furthermore, the end faces of the cathode separator 15 and the anode separator 18 extend to protrude from each of the end faces of the membrane electrode assembly, the cathode gas diffusion layer 14, and the anode gas diffusion layer 17. In the extended portion, a support member 23 is arranged between the cathode separator 15 and the anode separator 18. In the outer peripheral portion 21, channels are unnecessary in the cathode separator 15 and the anode separator 18. Therefore, grooves 15a and 18a are not formed (note that from...). Figure 3 It can be seen that grooves may form in some parts.

[0061] Cover plate 22 is arranged to bridge the end of the cathode-side surface of support member 23 and the end of the cathode-side surface of membrane electrode assembly. Cover plate 22 will be described below.

[0062] 1.2b. Support components

[0063] The support member 23 functions as a sealing member, sealing the gap between the cathode separator 15 and the anode separator 18 in the outer periphery 21 of the cell 10.

[0064] The support member 23 includes a substrate 23a and a bonding layer 23b disposed on each of the opposing surfaces (the surface facing the cathode side and the surface facing the anode side) of the substrate 23a. The bonding layer 23b seals the interior of the power generation section 11 by bonding to the cathode separator 15 and the anode separator 18. Therefore, the space between the cathode separator 15 and the anode separator 18 is bent to change according to the layers inserted therebetween. Figure 3 It can be seen that the space narrows in a portion of the part where the support member 23 is arranged separately, and the cathode diaphragm 15 and the anode diaphragm 18 are fixed with the support member 23 inserted therebetween.

[0065] The substrate 23a is made of a thermoplastic resin material that is electrically insulating and hermetically tight and has a high melting point. Examples of materials include crystalline polymers, more specifically engineering plastics. Examples of engineering plastics include polyethylene naphthalate (PEN) and polyethylene terephthalate (PET).

[0066] There is no particular limitation on the thickness of the substrate 23a, but it is preferably 0.05 mm or more and 0.25 mm or less.

[0067] As the bonding layer 23b, any well-known bonding layer can be used, as long as it has adhesive strength in the bonded state. Examples of bonding layers include modified polyolefins, wherein functional groups (e.g., maleic anhydride or epoxy resin) are introduced into the polyolefin to impart adhesiveness.

[0068] from Figure 3As can be seen, the support member 23 is arranged such that its end face faces the end face of the membrane electrode assembly and the anode gas diffusion layer 17, with a space S inserted between them, and extends to the side opposite to the power generation section 11. The space S absorbs the dimensional changes caused by the linear expansion of the support member 23, the membrane electrode assembly, etc., and can reduce damage caused by expansion and contraction.

[0069] 1.2c. Cover plate

[0070] As described above, the cover plate 22 is arranged to bridge the end of the cathode-side surface of the support member 23 and the end of the cathode-side surface of the membrane electrode assembly. Figure 4 It is focused on Figure 3 An enlarged view of the area near where the cover plate 22 is arranged. From Figure 3 and Figure 4 As can be seen, the cover plate 22 includes a sheet portion 22a and a permeation portion 22b laminated on the sheet portion 22a. The sheet portion 22a faces the membrane electrode assembly side, and the permeation portion 22b faces the cathode gas diffusion layer 14 side.

[0071] The sheet portion 22a is arranged such that a first end covers the surface end of the support member 23 on the cathode side, and a second end covers at least one surface end of the electrolyte membrane 12 and the cathode catalyst layer 13 (in this embodiment, the sheet portion 22a is arranged to cover the surface ends of both the electrolyte membrane 12 and the cathode catalyst layer 13). Thus, the cathode and anode can be appropriately separated from each other in the outer peripheral portion 21.

[0072] The sheet 22a is made of a material that prevents the permeation of fuel cell reactant gases. As a component that prevents reactant gas permeation, a membrane-like component made of resin (such as polypropylene, polyphenylene sulfide, polyethylene naphthalate, nylon, or ethylene-vinyl alcohol copolymer) can be used. Specifically, from the perspective of hydrolysis resistance and adhesion to the electrolyte membrane, nylon 11, nylon 12, nylon 9T, or ethylene-vinyl alcohol can be used. Furthermore, to improve adhesion to the electrolyte membrane 12, additives having amide groups, epoxy groups, hydroxyl groups, etc., can be added.

[0073] There is no particular limitation on the thickness of the sheet portion 22a, but it is preferably about 40 μm or more and 60 μm or less.

[0074] The permeation portion 22b is a layer that permeates into the cathode gas diffusion layer 14 and has adhesive properties for bonding the sheet portion 22a and the cathode gas diffusion layer 14. The permeation portion 22b is formed of a material with a melting point lower than that of the sheet portion 22a. Therefore, when heated, the permeation portion 22b is preferentially fluidized, allowing it to permeate into the cathode gas diffusion layer 14.

[0075] There is no particular limitation on the extent (penetration depth) to which the permeation portion 22b penetrates into the cathode gas diffusion layer 14. When the MPL 14b is provided in the cathode gas diffusion layer 14 as in the embodiment, it is preferable that the permeation portion 22b passes through the MPL 14b and reaches the diffusion member 14a. Thus, a reliable connection can be achieved.

[0076] like Figure 3 and Figure 4 As shown, the permeation portion 22b can be arranged on the entire surface of the sheet portion 22a (the surface on the side of the cathode gas diffusion layer 14). However, this embodiment is not limited to this configuration; the permeation portion 22b can be intermittently arranged on one surface of the sheet portion 22a, or it can be arranged on half of that one surface on the side serving as the support member 23.

[0077] There are no particular limitations on the material used to form the permeation portion 22b, as long as it melts and permeates into the cathode gas diffusion layer 14 and has adhesive properties for bonding the tab portion 22a and the cathode gas diffusion layer 14. From the perspective of relatively low melting point and excellent hydrolysis resistance, polyethylene or polypropylene can be preferred.

[0078] Furthermore, regarding the material used to form the permeation section 22b, in order to improve the bonding with MPL 14b, epoxy groups, hydroxyl groups, etc., can be copolymerized with polyethylene or polypropylene, or additives made of epoxy groups, hydroxyl groups, or amide groups can be added.

[0079] In addition, a compatibilizer may be used to improve the adhesion between the sheet portion 22a and the permeation portion 22b.

[0080] 1.2d effect

[0081] When one end of the cover plate is positioned between the cathode gas diffusion layer and the membrane electrode assembly, the thickness of the cover plate creates... Figure 4 The space indicated by C. This space tends to increase as the cover plate thickness increases. This increase in space may lead to damage to the membrane electrode assembly or the cathode gas diffusion layer.

[0082] On the other hand, as mentioned above, the cover plate requires both a sealing portion and an adhesive portion, and each of these portions needs to be thick enough to ensure functionality. Therefore, the space C will inevitably increase.

[0083] On the other hand, in the cover sheet according to this disclosure, the portion used for adhesion (permeation portion 22b) can be formed inside the cathode gas diffusion layer 14. Therefore, the thickness of the space C formed corresponds only to the sheet portion 22a and can be reduced, and the space C formed between the end of the sheet portion 22a of the cover sheet 22 on the membrane electrode assembly side and the cathode gas diffusion layer 14 can be reduced to a smaller size. Thus, the possibility of damage to the membrane electrode assembly or the cathode gas diffusion layer can be reduced, and leakage of reactive gases caused by damage can be reduced.

[0084] At this point, when the permeation portion 22b passes through the MPL 14b of the cathode gas diffusion layer 14 and reaches the diffusion member 14a, more reliable bonding and sealing can be achieved.

[0085] 1.2e. Another embodiment of the outer peripheral portion 1

[0086] Figure 5 This is a diagram illustrating another example of an embodiment of the outer periphery. Figure 5 From and Figure 4 Images viewed from the same perspective. Figure 5 In this example, the end face of the cathode catalyst layer 13 is located at the same position as the end face of the electrolyte membrane 12. In this case, the sheet portion 22a of the cover plate 22 is laminated onto the cathode catalyst layer 13, rather than onto the electrolyte membrane 12.

[0087] Even when using this embodiment, the same effect as described above is exhibited.

[0088] 1.2f. Another embodiment of the outer peripheral portion 2

[0089] Figure 6 This is a diagram illustrating another example of an embodiment of the outer periphery. Figure 6 From and Figure 4 Images viewed from the same perspective. Figure 6 In the example, in the sheet portion 22a of the cover plate 22, a tapered portion 22c as a tapered protrusion is provided at the end on the membrane electrode assembly side. By arranging the tapered portion 22c to embed at least a portion of the space C, the space C can be further reduced, and the effect is more significant.

[0090] 1.2g. Cover slip arrangement

[0091] There are no particular limitations on the method of arranging the cover plate 22 while allowing the permeation portion 22b to permeate into the cathode gas diffusion layer 14, and it can be done, for example, as follows. Figure 7 This is a diagram used to describe the method.

[0092] like Figure 7As shown, the cover plate 22 is arranged such that the end of the plate portion 22a contacts the end of the surface of the support member 23 and the end of the surface of the cathode catalyst layer 13 to bridge the ends, and the cathode gas diffusion layer 14 is arranged such that the MPL 14b contacts the permeation portion 22b side of the cover plate 22.

[0093] Next, the permeation section 22b is heated to a temperature at which only the permeation section 22b is fluid and softened and melted, and as... Figure 7 As indicated by the straight arrows, pressure is applied in the lamination direction of each layer. Thus, the permeation section 22b permeates into the cathode gas diffusion layer 14, and the layer structure according to each example is realized.

[0094] At this point, the thickness of the cover plate 22 before the permeation portion 22b penetrates into the cathode gas diffusion layer 14 is not particularly limited, but is preferably about 20 μm to 100 μm. From the perspective of more reliably ensuring mechanical strength, this thickness is more preferably 40 μm to 100 μm, and from the perspective of further reducing the space C and ensuring mechanical strength, this thickness is more preferably 40 μm to 80 μm.

[0095] 2. Fuel Cell

[0096] The fuel cell 30 is a component in which multiple (about 50 to 400) unit power generating cells 10 are laminated, and power is harvested from these unit power generating cells 10. Figure 8 The diagram illustrates an outline of the structure. The fuel cell 30 includes a stack housing 31, end plates 32, multiple cell units 10, a current collector 34, and a biasing member 35.

[0097] The stack housing 31 is a housing that accommodates a plurality of laminated cell units 10, current collectors 34, and biasing members 35. According to this embodiment, the stack housing 31 has a quadrilateral column shape, wherein a first end is open, a second end is closed, and a plate-like member protrudes along the edge of the opening to the side opposite to the opening to form a flange 31a.

[0098] The end plate 32 is a plate-shaped member and blocks the opening of the reactor shell 31. The end plate 32 is fixed to the reactor shell 31 by covering the overlapping portion of the flange 31a of the reactor shell 31 with the end plate 32, for example, by bolts and nuts.

[0099] The single-cell power generation battery 10 is as described above. Multiple single-cell power generation batteries 10 are laminated. In this case, the multiple single-cell power generation batteries 10 are laminated such that the cathode separator 15 of one single-cell power generation battery 10 overlaps with the anode separator 18 of another adjacent single-cell power generation battery 10. The grooves 15b of the cathode separator 15 and the grooves 18b of the anode separator 18 overlap each other to form coolant channels.

[0100] Current collector 34 is a component that collects current from the laminated multiple cell-type power generation cells 10. Therefore, current collector 34 is arranged at each of the first and second ends of the laminate of the cell-type power generation cells 10, with one of the current collectors 34 being the positive electrode and the remaining current collectors 34 being the negative electrode. Current collector 34 is connected to terminals (not shown) and is configured to be electrically connected to the outside of the fuel cell 30.

[0101] The biasing member 35 enters the stack housing 31 and applies pressure to the laminators of the cell 10 in the lamination direction. An example of the biasing member includes a leaf spring.

[0102] 3. Other

[0103] In the above description, it is assumed that each component on the cathode side is designated as "first" and each component on the anode side is designated as "second". Conversely, the same effect would be observed even if it were assumed that each component on the cathode side is designated as "second" and each component on the anode side is designated as "first".

Claims

1. A fuel cell, characterized in that... include: A membrane electrode assembly includes a first catalyst layer, a second catalyst layer, and an electrolyte membrane disposed between the first catalyst layer and the second catalyst layer; A first gas diffusion layer, laminated on the first catalyst layer, has at least a portion of an outer peripheral end portion disposed to pass through the outer peripheral end of the membrane electrode assembly, and includes a diffusion member and a microporous layer disposed on the surface of the diffusion member on one side of the first catalyst layer. A second gas diffusion layer is laminated on the second catalyst layer; Support members are arranged on at least a portion of the periphery surrounding the membrane electrode assembly; as well as A cover sheet is disposed between the first gas diffusion layer and the membrane electrode assembly to bridge the support member to at least one end of the electrolyte membrane and the first catalyst layer. The cover includes The sheet portion, which serves as a layer on one side of the membrane electrode assembly, and The permeation portion, laminated on the sheet portion, penetrates the microporous layer and permeates to the diffusion member. In the sheet portion of the cover, a tapered portion as a tapered protrusion is provided at the end on the side of the membrane electrode assembly.

2. The fuel cell according to claim 1, characterized in that, The end faces of the support and the end faces of the membrane electrode assembly are arranged to face each other through a gap.

Images