JP5608628B2 - Fuel cell - Google Patents

Description

  The present invention relates to a fuel cell in which an electrolyte membrane / electrode structure provided with electrodes each having an electrode catalyst layer and a gas diffusion layer on both sides of a solid polymer electrolyte membrane, and a separator are laminated.

  For example, a solid polymer fuel cell employs a solid polymer electrolyte membrane made of a polymer ion exchange membrane. This fuel cell has an electrolyte membrane / electrode structure (MEA) in which an anode electrode and a cathode electrode each made of an electrode catalyst (electrode catalyst layer) and porous carbon (gas diffusion layer) are disposed on both sides of a solid polymer electrolyte membrane. ) Is constituted by a separator (bipolar plate). Normally, in a fuel cell, a fuel cell stack in which a predetermined number of power generation cells are stacked is used as, for example, an in-vehicle fuel cell stack.

  In general, in an electrolyte membrane / electrode structure, the anode electrode and the cathode electrode have a smaller surface area than the solid polymer electrolyte membrane, and the outer peripheral edge of the solid polymer electrolyte membrane is the anode electrode and the cathode. It is exposed to the outside from the outer periphery of the electrode. For this reason, when the gas diffusion layer is thermocompression bonded to the solid polymer electrolyte membrane during the production of the electrolyte membrane / electrode structure, there is a problem that the fibers constituting the gas diffusion layer pierce the solid polymer electrolyte membrane.

  Therefore, for example, a fuel battery cell disclosed in Patent Document 1 is known. In this fuel cell, as shown in FIG. 6, a membrane electrode assembly 4 formed of an electrolyte membrane 1, a cathode-side catalyst layer 2a, and an anode-side catalyst layer 3a includes a cathode-side gas diffusion layer 2b. And the gas diffusion layer 3b on the anode side. Since the catalyst layers 2a and 3a have a smaller area than the electrolyte membrane 1, an exposed region 1a where the catalyst layers 2a and 3a are not present is formed on the outer peripheral edge of the electrolyte membrane 1. Yes.

  Further, in the end portions of the gas diffusion layers 2b and 3b arranged on both sides of the membrane electrode assembly 4, depressions 5a and 5b are formed at locations that are the peripheral edges of the catalyst layers 2a and 3a. Resin materials 6a and 6b are accommodated in the groove defined by the recesses 5a and 5b and the exposed region 1a from the catalyst layers 2a and 3a to the exposed region 1a. For this reason, it is supposed that the fluff protruding from the gas diffusion layers 2b and 3b is prevented from sticking into the electrolyte membrane 1.

JP 2011-146300 A

  By the way, in the above fuel cell, the solid polymer electrolyte membrane (electrolyte membrane 1) protrudes outward from the outer periphery of the anode electrode and the cathode electrode. For this reason, the fuel gas may pass through the solid polymer electrolyte membrane from the anode side to the cathode side, while the oxidant gas may pass through the solid polymer electrolyte membrane from the cathode side to the anode side.

For this reason, hydrogen and oxygen react with each other on the anode side and the cathode side to easily generate hydrogen peroxide (H ₂ O ₂ ) (H ₂ + O ₂ → H ₂ O ₂ ). This hydrogen peroxide is decomposed on the carbon support or platinum (Pt) in the electrode, and for example, a hydroxy radical (.OH) is generated. Thereby, there exists a problem of deteriorating a solid polymer electrolyte membrane and an electrode catalyst.

  The present invention solves this type of problem, prevents reaction gas from being mixed between the anode electrode and the cathode electrode, can effectively suppress deterioration of the solid polymer electrolyte membrane, etc. An object of the present invention is to provide a fuel cell that can be operated in a stable state.

  The present invention relates to a fuel cell in which an electrolyte membrane / electrode structure provided with electrodes each having an electrode catalyst layer and a gas diffusion layer on both sides of a solid polymer electrolyte membrane, and a separator are laminated.

In this fuel cell, at least one of the electrodes is set to have a smaller surface area than the solid polymer electrolyte membrane, and between the electrode catalyst layer and the gas diffusion layer constituting one of the electrodes, A porous sheet layer is disposed over the entire surface. The porous sheet layer has an outer peripheral edge extending outward from the outer periphery of the gas diffusion layer, and the outer peripheral edge is provided with a gas impervious portion subjected to a gas impervious treatment. Yes. A frame-shaped gas impermeable sheet is disposed on the outer periphery of the gas diffusion layer.

  In this fuel cell, the gas impermeable portion is preferably formed by subjecting the outer peripheral edge portion to press treatment or resin impregnation treatment.

  Furthermore, in this fuel cell, it is preferable that the gas impermeable portion directly faces the solid polymer electrolyte membrane.

  In this fuel cell, it is preferable that the gas impermeable portion has an overlapping portion in the stacking direction with the outer periphery of the electrode catalyst layer.

  According to the present invention, the porous sheet layer is disposed over the entire power generation surface between the electrode catalyst layer and the gas diffusion layer, and the porous sheet layer is disposed outside the outer periphery of the gas diffusion layer. A gas impervious portion is provided at the outer peripheral edge extending in the direction. For this reason, the fiber which comprises a gas diffusion layer does not pierce a solid polymer electrolyte membrane, and can protect the said solid polymer electrolyte membrane favorably.

  Moreover, there is no permeation of the reaction gas from the outer peripheral edge of the porous sheet layer to the solid polymer electrolyte membrane, and the reaction gas is surely suppressed from passing through the solid polymer electrolyte membrane and being mixed between the two electrodes. It becomes possible to do. Thereby, deterioration of a solid polymer electrolyte membrane etc. can be suppressed effectively and it becomes possible to drive | operate a fuel cell in a favorable state.

It is a principal part disassembled perspective view of the fuel cell which concerns on the 1st Embodiment of this invention. It is the II-II sectional view taken on the line of the said fuel cell in FIG. It is a disassembled perspective explanatory drawing of the electrolyte membrane and electrode structure which comprises the said fuel cell. It is a disassembled sectional view explaining the manufacturing method of the said electrolyte membrane and electrode structure. It is principal part cross-sectional explanatory drawing of the fuel cell which concerns on the 2nd Embodiment of this invention. It is explanatory drawing of the fuel battery cell currently disclosed by patent document 1. FIG.

  As shown in FIG. 1, in the fuel cell 10 according to the first embodiment of the present invention, the electrolyte membrane / electrode structure 12, the anode-side separator 14 and the cathode-side separator 16 are in the standing posture in the direction of arrow A ( For example, they are stacked in the horizontal direction). By stacking the plurality of fuel cells 10 in the direction of arrow A, for example, an in-vehicle fuel cell stack is configured. In addition, as the anode side separator 14 and the cathode side separator 16, for example, a carbon separator is used, but a metal separator may be used instead.

  The fuel cell 10 has a horizontally long shape, and an oxidant gas, for example, an oxygen-containing gas is supplied to one end edge in the arrow B direction (horizontal direction) in communication with each other in the arrow A direction that is the stacking direction. For this purpose, an oxidant gas inlet communication hole 18a and a fuel gas outlet communication hole 20b for discharging a fuel gas, for example, a hydrogen-containing gas, are arranged in the direction of arrow C (vertical direction).

  The other end edge of the fuel cell 10 in the direction of arrow B communicates with each other in the direction of arrow A, a fuel gas inlet communication hole 20a for supplying fuel gas, and an oxidant gas for discharging oxidant gas. The outlet communication holes 18b are arranged in the arrow C direction.

  A cooling medium inlet communication hole 22a for supplying a cooling medium is provided at one end edge (upper edge) in the arrow C direction of the fuel cell 10, and the other end edge of the fuel cell 10 in the arrow C direction. A cooling medium outlet communication hole 22b for discharging the cooling medium is provided at the (lower edge).

  A fuel gas passage 24 communicating with the fuel gas inlet communication hole 20a and the fuel gas outlet communication hole 20b extends in the direction of arrow B on the surface 14a of the anode separator 14 facing the electrolyte membrane / electrode structure 12. Provided. An inlet buffer portion 24 a is provided on the inlet side of the fuel gas passage 24, while an outlet buffer portion 24 b is provided on the outlet side of the fuel gas passage 24.

  Between the fuel gas inlet communication hole 20a and the inlet buffer portion 24a, a bridge portion 28a in which a plurality of inlet connection channels 26a are covered with a lid body 27a is formed. Between the fuel gas outlet communication hole 20b and the outlet buffer portion 24b, a bridge portion 28b is formed in which a plurality of outlet connection channels 26b are covered with a lid body 27b.

  An oxidant gas flow path 30 communicating with the oxidant gas inlet communication hole 18a and the oxidant gas outlet communication hole 18b is provided on the surface 16a of the cathode separator 16 facing the electrolyte membrane / electrode structure 12. The oxidant gas channel 30 is configured in the same manner as the fuel gas channel 24, and a detailed description thereof is omitted. The anode-side separator 14 and the cathode-side separator 16 integrally form a cooling medium flow path 32 between the faces 14b, 16b facing each other.

  A first seal member 34 is integrally or individually provided on the surfaces 14 a and 14 b of the anode separator 14 so as to go around the outer peripheral edge of the anode separator 14. On the surfaces 16a and 16b of the cathode side separator 16, a second seal member 36 is integrally or individually provided around the outer peripheral edge of the cathode side separator 16. The first seal member 34 includes a flow path seal portion 34a that surrounds a fuel gas region including the fuel gas flow channel 24, the inlet buffer portion 24a, and the outlet buffer portion 24b. The second seal member 36 has a flow path seal portion 36a surrounding an oxidant gas region including the oxidant gas flow channel 30, an inlet buffer portion (not shown), and an outlet buffer portion (not shown).

  The first seal member 34 and the second seal member 36 are, for example, EPDM, NBR, fluororubber, silicon rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene, or acrylic rubber, or a cushioning material. Or use packing material.

  The electrolyte membrane / electrode structure 12 has a horizontally long shape, for example, a solid polymer electrolyte membrane 38 in which a thin film of perfluorosulfonic acid is impregnated with water, and an anode electrode 40 sandwiching the solid polymer electrolyte membrane 38. And a cathode electrode 42. The outer dimensions of the solid polymer electrolyte membrane 38 are set larger than the outer dimensions of the anode electrode 40 and the cathode electrode 42. The anode electrode 40 and the cathode electrode 42 may be set to different sizes.

  As the solid polymer electrolyte membrane 38, an HC (hydrocarbon) electrolyte is used in addition to a fluorine electrolyte. The solid polymer electrolyte membrane 38 may have, for example, a structure in which the main chain has a polyphenylene structure and a side chain having a sulfonic acid group.

  As shown in FIG. 2, the anode electrode 40 and the cathode electrode 42 are formed by uniformly applying porous carbon particles carrying a platinum alloy on the surface thereof to the surface of the solid polymer electrolyte membrane 38, as will be described later. Electrode catalyst layers 40a and 42a, and gas diffusion layers 40b and 42b made of carbon paper or the like.

  The gas diffusion layers 40b and 42b are laminated on the electrode catalyst layers 40a and 42a via the porous sheet layers 44a and 44b. The porous sheet layers 44a and 44b include an electron conductive substance and a water repellent resin, and have conductivity. As the electron conductive substance, for example, carbon powder (carbon black, furnace black, acetylene black) such as carbon fiber or carbon nanotube is used alone or in combination of two or more kinds. It contains at least one of fluororesin, PVDF (polyvinylidene fluoride), PVF (polyvinyl fluoride), PTFE (polytetrafluoroethylene), amorphous fluororesin, and silicone resin.

  The porous sheet layers 44a and 44b are formed into frame-like gas-impermeable portions 44aa and 44bb by subjecting the outer peripheral portion to press treatment or resin impregnation treatment in an independent sheet shape state. The gas impermeable portions 44aa and 44bb have overlapping portions with the outer peripheries of the electrode catalyst layers 40a and 42a, and prevent gas permeation through the solid polymer electrolyte membrane 38. The solid polymer electrolyte membrane 38 extends to the outside of the porous sheet layers 44a and 44b, and can reliably prevent mixing of the reaction gas (fuel gas and oxidant gas) between the two electrodes.

  Frame-shaped gas-impermeable sheets 46a and 46b are disposed on the outer periphery of the gas diffusion layers 40b and 42b. The surface positions of the gas-impermeable sheets 46a and 46b are arranged at the same positions as the surface positions of the gas diffusion layers 40b and 42b, and form the same plane with no step as a whole. The flow path seal portion 34a of the first seal member 34 is disposed so as to cover the boundary portion between the outer peripheral end of the gas diffusion layer 40b and the inner peripheral end of the gas impermeable sheet 46a, while the flow path of the second seal member 36 is provided. The seal portion 36a is disposed so as to cover a boundary portion between the outer peripheral end of the gas diffusion layer 42b and the inner peripheral end of the gas impermeable sheet 46b. The gas impermeable sheets 46a and 46b are made of, for example, a film made of PEN (polyethylene naphthalate).

  As shown in FIGS. 2 and 3, the surface areas S1 of the electrode catalyst layers 40a and 42a are set smaller than or equal to the surface areas S2 of the gas diffusion layers 40b and 42b. The porous sheet layers 44a and 44b are set to have a smaller outer dimension than the solid polymer electrolyte membrane 38 and larger than the electrode catalyst layers 40a and 42a and the gas diffusion layers 40b and 42b. In the porous sheet layers 44a and 44b, the surface areas S3 of the gas permeable regions provided inside the gas impermeable portions 44aa and 44bb are the surface areas S1 of the electrode catalyst layers 40a and 42a and the gas diffusion layers 40b and 42b. It is set smaller than the surface area S2.

  The porous sheet layer 44a is provided in a region wider than the fuel gas region including the fuel gas passage 24, the inlet buffer portion 24a and the outlet buffer portion 24b, and the porous sheet layer 44b includes the oxidant gas passage 30, It is provided in a region wider than the oxidant gas region including the inlet buffer portion (not shown) and the outlet buffer portion (not shown).

  Next, a method for producing the electrolyte membrane / electrode structure 12 will be described below.

  First, as shown in FIGS. 3 and 4, after the solid polymer electrolyte membrane 38 is formed in a rectangular shape, the electrode catalyst layer 40 a and the electrode catalyst are formed on the surface 38 a and the surface 38 b of the solid polymer electrolyte membrane 38. Layer 42a is formed.

  Specifically, the electrode catalyst layer 40a and the electrode catalyst layer 42a are prepared by, for example, preparing a catalyst paste in which a platinum catalyst and an ion conductive polymer solution are mixed, and applying the catalyst paste on a PTFE sheet. Produced. Further, after the catalyst layer side of the electrode catalyst layer 40a and the electrode catalyst layer 42a is thermocompression bonded to both surfaces 38a, 38b of the solid polymer electrolyte membrane 38, the PTFE sheet is transferred by peeling.

  On the other hand, as described above, the porous sheet layers 44a and 44b having a larger outer dimension than the gas diffusion layers 40b and 42b are prepared. Frame-shaped gas-impermeable portions 44aa and 44bb are formed on the outer peripheral portions of the porous sheet layers 44a and 44b by performing press treatment or impregnation treatment with a resin material. In the above pressing process, the outer peripheral portions of the porous sheet layers 44a and 44b are configured to be thicker than other portions in advance, and the outer peripheral portions are equal in thickness to the other portions. You may carry out by pressurizing.

  Therefore, the porous sheet layers 44a and 44b covered with the frame-shaped gas impermeable sheets 46a and 46b and the gas diffusion layers 40b and 42b are positioned and arranged with respect to each other. In this state, the gas diffusion layers 40b and 42b are pressurized and heated (hot pressed) to be thermocompression bonded to the porous sheet layers 44a and 44b.

  Next, the porous sheet layers 44a and 44b on which the gas diffusion layers 40b and 42b are thermocompression bonded are integrated with the solid polymer electrolyte membrane 38 in which the electrode catalyst layers 40a and 42a are provided on both surfaces 38a and 38b. In addition, the porous sheet layers 44a and 44b are covered with frame-shaped gas-impermeable sheets 46a and 46b. Thereby, the electrolyte membrane / electrode structure 12 is manufactured.

  The operation of the fuel cell 10 configured as described above will be described below.

  As shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 18a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 20a. Further, a cooling medium such as pure water or ethylene glycol is supplied to the cooling medium inlet communication hole 22a.

  The oxidant gas is introduced into the oxidant gas flow path 30 of the cathode-side separator 16 from the oxidant gas inlet communication hole 18a. The oxidant gas flows in the direction of arrow B along the oxidant gas flow path 30 and moves along the cathode electrode 42 of the electrolyte membrane / electrode structure 12.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 24 of the anode side separator 14 from the fuel gas inlet communication hole 20a. In the fuel gas channel 24, the fuel gas flows in the direction of arrow B, and moves along the anode electrode 40 of the electrolyte membrane / electrode structure 12.

  Therefore, in the electrolyte membrane / electrode structure 12, the oxidant gas supplied to the cathode electrode 42 and the fuel gas supplied to the anode electrode 40 are consumed by an electrochemical reaction in the electrode catalyst layers 42a and 40a. Power generation is performed.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 42 is discharged to the oxidant gas outlet communication hole 18b. Similarly, the fuel gas consumed by being supplied to the anode electrode 40 is discharged to the fuel gas outlet communication hole 20b.

  On the other hand, the cooling medium supplied to the cooling medium inlet communication hole 22 a is introduced into the cooling medium flow path 32 formed between the anode side separator 14 and the cathode side separator 16. In the cooling medium flow path 32, the cooling medium moves in the direction of gravity (arrow C direction). Therefore, the cooling medium is cooled over the entire power generation surface of the electrolyte membrane / electrode structure 12 and then discharged to the cooling medium outlet communication hole 22b.

  In this case, in the first embodiment, as shown in FIGS. 2 and 3, the porous sheet layer 44 a is formed between the electrode catalyst layers 40 a and 42 a and the gas diffusion layers 40 b and 42 b over the entire power generation surface. 44b, and the porous sheet layers 44a and 44b are provided with gas-impermeable portions 44aa and 44bb at outer peripheral edges extending outward from the outer periphery of the gas diffusion layers 40b and 42b. .

  For this reason, when manufacturing the electrolyte membrane / electrode structure 12, particularly when integrating the gas diffusion layers 40b and 42b into the solid polymer electrolyte membrane 38, or when applying a tightening load to the fuel cell 10, The fibers constituting the gas diffusion layers 40b and 42b do not pierce the solid polymer electrolyte membrane 38. Therefore, the solid polymer electrolyte membrane 38 can be well protected.

  Moreover, on one surface of the solid polymer electrolyte membrane 38, the gas impermeable portion 44aa of the porous sheet layer 44a is disposed across the outer peripheral edge portion of the electrode catalyst layer 40a, and the inside of the gas impermeable portion 44aa A flow path seal portion 34a is disposed so as to cover a boundary portion between the outer peripheral end of the gas diffusion layer 40b laminated on the peripheral portion and the inner peripheral end of the gas impermeable sheet 46a. Similarly, on the other surface of the solid polymer electrolyte membrane 38, a gas impermeable portion 44bb of the porous sheet layer 44b is disposed across the outer peripheral edge of the electrode catalyst layer 42a, and the gas impermeable portion 44bb A flow path seal portion 36a is disposed so as to cover a boundary portion between the outer peripheral end of the gas diffusion layer 42b laminated on the inner peripheral edge and the inner peripheral end of the gas impermeable sheet 46b.

  Thereby, the reaction gas (fuel gas or oxidant gas) does not permeate from the outer peripheral edge of the porous sheet layers 44a and 44b to the solid polymer electrolyte membrane 38. For this reason, it becomes possible to reliably suppress the reaction gas from passing through the solid polymer electrolyte membrane 38 and mixing between the anode electrode 40 and the cathode electrode 42. Accordingly, it is possible to effectively suppress the deterioration of the solid polymer electrolyte membrane 38 and the like, and the effect that the fuel cell 10 can be operated in a good state is obtained.

  FIG. 5 is an explanatory cross-sectional view of a main part of a fuel cell 50 according to the second embodiment of the present invention. The same components as those of the fuel cell 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fuel cell 50 sandwiches an electrolyte membrane / electrode structure 52 between the anode side separator 14 and the cathode side separator 16. The electrolyte membrane / electrode structure 52 holds the solid polymer electrolyte membrane 38 between the anode electrode 54 and the cathode electrode 56. The electrode catalyst layer 40aL constituting the anode electrode 54 is set to have a larger surface area than the electrode catalyst layer 42aS constituting the cathode electrode 56, and constitutes a so-called step MEA. In contrast to the above, the cathode electrode 56 may constitute a step MEA having a larger outer dimension than the anode electrode 54.

  On one surface side of the solid polymer electrolyte membrane 38, an electrode catalyst layer 40aL, a porous sheet layer 44aL, a gas diffusion layer 40bL, and a gas impermeable sheet 46aL are provided. On the other surface side of the solid polymer electrolyte membrane 38, there are provided an electrode catalyst layer 42aS, a porous sheet layer 44bS, a gas diffusion layer 42bS, and a gas impermeable sheet 46bS which are smaller in size than components on one surface side. It is done.

  In the second embodiment configured as described above, the porous sheet layers 44aL and 44bS are arranged over the entire power generation surface between the electrode catalyst layers 40aL and 42aS and the gas diffusion layers 40bL and 42bS. The porous sheet layers 44aL and 44bS are provided with gas-impermeable portions 44aa and 44bb at outer peripheral edges that extend outward from the outer periphery of the gas diffusion layers 40bL and 42bS.

  Moreover, on one surface of the solid polymer electrolyte membrane 38, the gas impervious portion 44aa of the porous sheet layer 44aL is disposed across the outer peripheral edge portion of the electrode catalyst layer 40aL, and the inside of the gas impermeable portion 44aa A flow path seal portion 34a is disposed so as to cover a boundary portion between the outer peripheral end of the gas diffusion layer 40bL laminated on the peripheral portion and the inner peripheral end of the gas impermeable sheet 46aL. Similarly, on the other surface of the solid polymer electrolyte membrane 38, a gas impermeable portion 44bb of the porous sheet layer 44bS is disposed across the outer peripheral edge portion of the electrode catalyst layer 42aS, and the gas impermeable portion 44bb A flow path seal portion 36a is disposed so as to cover a boundary portion between the outer peripheral end of the gas diffusion layer 42bS laminated on the inner peripheral edge and the inner peripheral end of the gas impermeable sheet 46bS.

  For this reason, in the second embodiment, the solid polymer electrolyte membrane 38 is well protected, and the deterioration of the solid polymer electrolyte membrane 38 and the like can be effectively suppressed, and the fuel cell 50 is kept in a good state. The same effects as those of the first embodiment can be obtained, such as enabling driving.

DESCRIPTION OF SYMBOLS 10, 50 ... Fuel cell 12, 52 ... Electrolyte membrane electrode assembly 14, 16 ... Separator 18a ... Oxidant gas inlet communication hole 18b ... Oxidant gas outlet communication hole 20a ... Fuel gas inlet communication hole 20b ... Fuel gas outlet communication Hole 22a ... Cooling medium inlet communication hole 22b ... Cooling medium outlet communication hole 24 ... Fuel gas flow path 24a ... Inlet buffer section 24b ... Outlet buffer section 30 ... Oxidant gas flow path 32 ... Cooling medium flow paths 34, 36 ... Seal members 34a, 36a ... flow path seal portion 38 ... solid polymer electrolyte membrane 40, 54 ... anode electrodes 40a, 40aL, 42a, 42aS ... electrode catalyst layers 40b, 40bL, 42b, 42bS ... gas diffusion layers 42, 56 ... cathode electrodes 44a 44aL, 44b, 44bS ... porous sheet layers 44aa, 44bb ... gas impervious portions 46a, 46aL, 46b, 46 S ... gas-impermeable sheet

Claims (4)

A fuel cell in which an electrolyte membrane / electrode structure provided with electrodes each having an electrode catalyst layer and a gas diffusion layer on both sides of a solid polymer electrolyte membrane and a separator are laminated,
At least one of the electrodes is set to have a smaller surface area than the solid polymer electrolyte membrane, and the entire surface of the power generation surface is interposed between the electrode catalyst layer and the gas diffusion layer constituting one of the electrodes. A porous sheet layer is disposed,
The porous sheet layer has an outer peripheral edge portion extending outward from the outer periphery of the gas diffusion layer, the outer peripheral portion, with the gas impermeable section of the gas impermeable processing has been performed is provided ,
A fuel cell , wherein a frame-shaped gas-impermeable sheet is disposed on an outer periphery of the gas diffusion layer .   2. The fuel cell according to claim 1, wherein the gas impermeable portion is formed by subjecting the outer peripheral edge portion to a press treatment or a resin impregnation treatment. 3.   3. The fuel cell according to claim 1, wherein the gas impermeable portion directly faces the solid polymer electrolyte membrane. 4. The fuel cell according to any one of claims 1 to 3, wherein the gas impermeable section, a fuel cell characterized by having an overlap portion on the outer periphery and the stacking direction of the electrode catalyst layer.

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