JP2006024465A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell, of which, adhesiveness and compliance of a gasket to an MEA is improved, keeping airtightness of a gas flow passage and a cooling water flow passage well for a long period. <P>SOLUTION: On the fuel cell comprising an electrolyte film, a film-electrode assembly 501 having an anode side electrode and a cathode side electrode arranged so as to interpose the electrolyte film, and separators interposing and holding the film-electrode assembly 501, the separator has a fuel gas plate 101 as a plate-shaped member having a fuel gas flow passage on a face opposing the anode side electrode, and an oxidant gas plate 201 as a plate-shaped member having an oxidant gas flow passage on a face opposing the cathode side electrode. A face of the fuel gas plate 101 at the opposite side of the face facing the anode side electrode is superposed on a face of the oxidant gas plate 201 at the opposite side of the face facing the cathode side electrode through an O-ring-shaped gasket 401, and the film-electrode assembly is interposed between and held by the separators through sheet-shaped sealing members 402. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell in which an MEA (membrane electrode assembly) in which an anode side electrode and a cathode side electrode are arranged on both surfaces of an electrolyte membrane is sandwiched between separators.

  The basic structure of a fuel cell is, for example, a MEA (Membrane Electrode Assembly) in which gas diffusion layers having electrode functions are formed on both sides of a solid electrolyte membrane, and a flow path through which gas or the like flows is provided. The structure is sandwiched between the separators. Practically, a fuel cell stack in which a plurality of MEAs and separators are alternately stacked is used.

Since fuel cells generate heat together with electricity, in order to maintain stable power generation, it is necessary to cool the inside of the stack using a cooling medium such as cooling water so that the unit fuel cells have a uniform temperature distribution. is there. For this purpose, a flow path through which a cooling medium flows is provided in the fuel cell stack. Such a structure of the fuel cell stack is disclosed in Patent Document 1, for example.
JP 2001-52723 A

  A gap between the MEA and the separator is sealed with a gasket. The solid polymer film that forms the MEA deforms over time, so if the adhesion and followability of the gasket to the MEA are poor, a gas leak will occur between the MEA and the separator, causing a decrease in battery performance. There is.

  Conventionally, an O-ring gasket or the like has been used for this gasket, but further improvement has been desired in the adhesion and followability of the gasket to the MEA.

  The present invention has been made in view of such circumstances, and improves the adhesion and followability of the gasket to the MEA, and improves the gas channel airtightness and the cooling water channel airtightness over a long period of time. Therefore, an object of the present invention is to provide a fuel cell that can prevent deterioration of fuel cell performance.

According to the present invention, in a fuel cell having an electrolyte membrane, a membrane electrode assembly having an anode side electrode and a cathode side electrode arranged across the electrolyte membrane, and a separator sandwiching the membrane electrode assembly,
The separator is a plate member having a fuel gas channel provided on the surface facing the anode side electrode, and a plate member having an oxidant gas channel provided on the surface facing the cathode side electrode And an oxidant gas plate
The surface opposite to the surface facing the anode side electrode of the fuel gas plate and the surface opposite to the surface facing the cathode side electrode of the oxidant gas plate are overlapped via an O-ring gasket,
A fuel cell is provided in which a membrane electrode assembly is sandwiched between separators via a sheet-like seal member.

  In the fuel cell, the sheet-like seal member is preferably made of olefin resin, ethylene propylene rubber, fluororesin or fluororubber.

  In the fuel cell, the O-ring gasket is preferably made of a silicone resin or a silicone rubber.

In the fuel cell, the inlet of the fuel gas channel is vertically above the outlet of the fuel gas channel,
The inlet of the oxidant gas channel is vertically above the outlet of the oxidant gas channel, and in each of the fuel gas channel and the oxidant gas channel, the channel length of the part directed vertically upward is the respective gas channel. It is preferably less than 50% of the total flow path length.

  In the fuel cell, at least one of a surface opposite to the surface facing the anode side electrode of the fuel gas plate and a surface opposite to the surface facing the cathode side electrode of the oxidant gas plate, A cooling medium flow path can be formed.

In the fuel cell, the fuel gas channel and the oxidant gas channel are arranged in parallel and / or opposite to each other, and
The cooling medium flow path is preferably orthogonal to the fuel gas flow path and the oxidant gas flow path.

In the fuel cell in which the cooling medium flow path is formed, the fuel gas plate has through holes at the inlet end and the outlet end of the fuel gas flow path, respectively, and the fuel gas flow path inlet through hole and the fuel gas flow path outlet pass through. A hole,
The oxidant gas plate is provided with through holes at the inlet end and the outlet end of the oxidant gas flow path to form an oxidant gas flow path inlet through hole and an oxidant gas flow path outlet through hole,
Separately from these through holes, the fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging fuel gas in the thickness direction through both gas plates, and the fuel gas supply communication holes and A pair of communication holes for supplying and discharging the oxidant gas in the thickness direction through the gas plates are provided as fuel gas discharge communication holes, and the oxidant gas supply communication hole and the oxidant gas discharge communication are provided. A hole,
On the surface opposite to the surface facing the anode side electrode of the fuel gas plate, the fuel gas channel inlet through hole and the fuel gas supply communication hole communicate with each other, the fuel gas channel outlet through hole, and the fuel gas discharge. A flow path communicating with the communication hole is formed,
A channel for connecting the oxidant gas flow channel inlet through hole and the oxidant gas supply communication hole to the surface opposite to the surface facing the cathode side electrode of the oxidant gas plate and the oxidant gas flow channel outlet through hole And a flow path that connects the oxidant gas discharge communication hole,
The fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging the cooling medium in the thickness direction through the gas plates at both ends of the cooling medium flow path. And a cooling medium discharge communication hole.

In this fuel cell, the flow path cross-sectional area of the flow path that communicates each through hole and the corresponding communication hole,
It is preferable to decrease in the direction from the communication hole toward the through hole.

  In the fuel cell, the separator is preferably provided along the vertical direction.

  In this fuel cell, the maximum vertical dimension of the cooling medium supply communication hole and the maximum vertical dimension of the cooling medium discharge communication hole are both 80% or more of the maximum vertical dimension of the anode side electrode and the cathode side electrode. It is preferable that

  According to the present invention, the adhesion and followability of the gasket to the MEA can be improved, and the gas channel airtightness and the cooling water channel airtightness can be improved over a long period of time. A fuel cell stack capable of preventing the above is provided.

  In the present invention, a sheet-like seal member is used for the seal between the separator and the MEA. As a material for the sheet-like sealing member, a material having high adhesion to the MEA and a high follow-up to the aging of the MEA, such as an olefin resin, particularly a thermosetting olefin resin; an ethylene propylene rubber (EPDM); a fluororesin Alternatively, fluororubber; silicone resin or silicone rubber can be used. These materials may be mixed with silicon carbide powder and / or carbon black as appropriate. A sheet-shaped sealing member can be obtained by appropriately providing an opening for accommodating an electrode, a hole for circulating gas, and the like in a sheet made of these materials.

  In addition to adhesion to MEA and followability, it takes into account economic properties such as heat resistance, moldability, creep characteristics, gas barrier properties, acid resistance, oxidation resistance, raw material costs and vulcanization process temperature. It is preferable to select a material for the sheet-like sealing member. Silicone-based seal members are excellent in heat resistance, moldability, and creep characteristics. In addition, the fluorine-based seal member is very excellent in the above-described physical properties. EPDM exhibits a relatively well-balanced characteristic. The olefin resin seal seal member is excellent in oxidation resistance and gas barrier properties. From the viewpoint of resistance to the use environment of the sheet-like sealing member, a fluororesin or fluororubber, EPDM, an olefin resin, particularly a thermosetting olefin resin is preferable. The thickness of the sheet-like sealing member is preferably about 0.1 mm to 0.4 mm, although it depends on the thickness of the diffusion layer.

  In the present invention, a separator having a structure in which two plate members (a fuel gas plate and an oxidant gas plate) are overlapped via an O-ring gasket is used. As for the seal between the fuel gas plate and the oxidant gas plate, there is no need to consider the adhesion and followability to the MEA, and the O-ring gasket is easy to handle and has the workability when assembling the fuel cell. This is because it is favorable and suitable for mass production.

  The same material as that of the sheet-shaped sealing member can be used for the O-ring gasket, but a silicone resin or a silicone rubber is preferable from the viewpoint of economy in practical use.

  Moreover, in order to improve the adhesiveness of a sheet-like sealing member and MEA, a sheet-like sealing member and MEA can be adhere | attached using an adhesive agent. Examples of the adhesive include water-based or organic solvent-based fluororesin dispersion PTFE (polytetrafluoroethylene), or water-based or organic solvent-based fluororesin dispersion FEP (tetrafluoroethylene-hexafluoropropylene copolymer). Polymer) and the like. From the viewpoint of adhesiveness, the content of these solid particles is preferably in the range of 10% by mass to 50% by mass. Alternatively, a cellulose-based material can be used as the adhesive, and for example, a solution obtained by dissolving cellulose such as hydroxypropylcellulose, methylcellulose, or hydroxypropylmethylcellulose, hydroxyethylmethylcellulose in water or an organic solvent can be used. . The concentration of celluloses in the solution is preferably 2% by mass or more and 20% by mass or less from the viewpoint of adhesiveness.

  Hereinafter, an embodiment of the fuel cell of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  In the operation of the fuel cell, the separator is preferably placed vertically from the viewpoint of easy drainage of generated water. That is, it is preferable that the separator is arranged along the vertical direction, in other words, the thickness direction of the separator is horizontal. Furthermore, from the viewpoint of the ability to discharge water that may be contained in the fuel gas and oxidant gas, when the separator is placed vertically, both the fuel gas and oxidant gas are supplied to the gas flow path from above. However, it is preferable to discharge from the lower part. Although not limited to such an arrangement, in the example shown below, such an arrangement is adopted. Here, a solid polymer fuel cell is shown.

  1 and 2 show a surface of the fuel gas plate 101 facing the anode side electrode (hereinafter, the surface facing the electrode is referred to as an electrode facing surface) and a surface on the opposite side (hereinafter referred to as the back surface). . A fuel gas flow path 102 is provided on the electrode facing surface of the fuel gas plate. 3 and 4 show a surface (electrode facing surface) facing the cathode side electrode and an opposite surface (back surface) of the oxidant gas plate 201, respectively. An oxidant gas flow path 202 is provided on the electrode facing surface of the oxidant gas plate. These gas plates are rectangular plate-like members (long sides along the horizontal direction) having grooves and holes, and have the same vertical and horizontal dimensions.

  The fuel gas channel and the oxidant gas channel are provided so that the fuel gas and the oxidant gas are in parallel flow and / or counterflow. In order to make the current density distribution as uniform as possible, it is particularly preferable that the current density distribution is provided so as to be generally counterflow. Each of the fuel gas channel and the oxidant gas channel shown in FIGS. 1 and 3 has a plurality of grooves arranged in a bellows on each gas plate. In each of the straight portions, the fuel gas and the oxidant gas are parallel flows that flow in the same direction, but the inlet of the fuel gas channel is provided on the side close to the outlet of the oxidant gas channel. The inlet of the flow path is provided on the side close to the outlet of the fuel gas flow path, and the entire flow is a counter flow. The fuel gas flow path and the oxidant gas flow path need only be substantially parallel and / or opposed to each other, but as described above, the fuel gas flow path and the oxidant gas flow path are opposed to each other as a whole (locally The gas flow paths may be parallel flows).

  The fuel gas plate and the oxidant gas plate are overlapped, and at this time, the back surfaces of the two gas plates face each other. In addition, the two gas plates are overlapped with an O-ring gasket 401 shown in FIG. Sealing member placement grooves 103 and 203 for fitting O-ring gaskets are provided on the back surfaces of both gas plates.

  A cooling medium flow path is formed on at least one of the back surface of the fuel gas plate and the back surface of the oxidant gas plate. Here, the cooling medium flow path 301 is formed on the back surface of the oxidant gas plate 201 as shown in FIG. And no coolant flow path is provided on the back surface of the fuel gas plate.

  The cooling medium flow path is orthogonal to the fuel gas flow path and the oxidant gas flow path. In the fuel cell in which the fuel gas and the oxidant gas are in parallel flow and / or counter flow, it is preferable that the cooling medium be orthogonal to the flow direction of the fuel gas and oxidant gas. The one-dimensional temperature distribution along the flow direction of the cooling medium as seen when the flow of the cooling medium is parallel flow or counter flow with respect to the flow of the fuel gas and the oxidant gas is suppressed. This is because the uniformity of the temperature distribution in the inside can be improved, and the power generation efficiency of the fuel cell and the life of the solid electrolyte membrane can be improved. The cooling medium flow path only needs to be substantially orthogonal to the fuel gas flow path and the oxidant gas flow path.

  As the cooling medium, a known medium such as pure water, city water, ethylene glycol, oil or the like can be used as a cooling medium for the fuel cell.

  The fuel gas plate is provided with through holes at the inlet end and the outlet end of the fuel gas flow path to form a fuel gas flow path inlet through hole 104 and a fuel gas flow path outlet through hole 105, respectively. The oxidant gas plate is provided with through holes at the inlet end and the outlet end of the oxidant gas flow path to form an oxidant gas flow path inlet through hole 204 and an oxidant gas flow path outlet through hole 205, respectively.

  In addition to these through holes, the fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging fuel gas in the thickness direction through both gas plates, and the fuel gas supply communication hole 304a. In addition, the fuel gas discharge communication hole 305a is used. Also, a pair of communication holes for supplying and discharging the oxidant gas in the thickness direction through both gas plates are provided to form an oxidant gas supply communication hole 304b and an oxidant gas discharge communication hole 305b. The fuel gas supply communication hole and the oxidant gas supply communication hole are provided in the upper part of both gas plates, and are arranged at positions close to the fuel gas channel inlet through hole and the oxidant gas channel inlet through hole, respectively. The fuel gas discharge communication hole and the oxidant gas discharge communication hole are provided at the lower portions of both gas plates, and are disposed at positions close to the fuel gas channel outlet through hole and the oxidant gas channel outlet through hole, respectively. These communication holes have a long shape in the horizontal (horizontal) direction, more specifically, a substantially rectangular shape. The fuel gas supply communication hole and the oxidant gas supply communication hole are provided at positions diagonal to the fuel gas discharge communication hole and the oxidant gas discharge communication hole, respectively.

  A flow path (fuel gas inlet side gas delivery flow path) 106 for connecting the fuel gas flow path inlet through hole 104 and the fuel gas supply communication hole 304a to the back surface of the fuel gas plate, a fuel gas flow path outlet through hole, and fuel gas A flow path (fuel gas outlet side gas transfer flow path) 107 that communicates with the discharge communication hole is formed. The fuel gas is supplied from the fuel gas supply communication hole 304a through the fuel gas inlet side gas transfer passage 106 to the fuel gas passage 102 from the fuel gas passage inlet through hole 104, and after being involved in the reaction, the fuel gas flow The fuel is discharged from the passage outlet through hole 105 to the fuel gas discharge communication hole 305a through the fuel gas outlet side gas transfer passage 107.

  A flow path (oxidant gas inlet side gas delivery flow path) 206 for communicating the oxidant gas flow path inlet through hole 204 and the oxidant gas supply communication hole 304b on the back surface of the oxidant gas plate and an oxidant gas flow path outlet A flow path (oxidant gas outlet side gas delivery flow path) 207 that connects the through hole 205 and the oxidant gas discharge communication hole 305b is formed.

  The cross-sectional area of the gas delivery channel is preferably small in the direction from the communication hole toward the through hole. Here, the gas delivery channel is formed by a plurality of grooves provided in the gas plate, the depth of the grooves is constant, and the width of the grooves is narrowed in the direction from the communication hole to the through hole. Fuel gas and oxidant gas often contain moisture, but with such a configuration, pressure loss is gradually generated when the wet gas flows from the through hole to the through hole or from the through hole to the through hole. This has the effect of alleviating pressure fluctuations due to the passage of droplets.

  The fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging the cooling medium in the thickness direction through the gas plates at both ends of the cooling medium flow path. 302 and the cooling medium discharge communication hole 303. The cooling medium supply communication hole and the cooling medium discharge communication hole are provided on the sides of both gas plates, and the cooling medium is arranged in the horizontal direction in the order of the cooling medium supply communication hole 302, the cooling medium flow path 301, and the cooling medium discharge communication hole 303. Circulate. Thus, the coolant supply communication hole 302 is disposed closer to the oxidant gas inlet through hole, and the coolant discharge passage 302 is disposed closer to the fuel gas inlet through hole. Although preferable from the viewpoint of distribution uniformity, the flow direction of the cooling medium is not limited to this. That is, in some cases, the cooling medium is supplied to the cooling medium flow path 301 from the communication hole shown as the cooling medium discharge communication hole 302 in the figure, and the cooling medium is discharged from the communication hole shown as the cooling medium supply communication hole 303. You can also. Each of the cooling medium supply communication hole and the cooling medium discharge communication hole has a long shape in the vertical direction, specifically, a substantially rectangular shape.

  The fuel gas channel inlet (fuel gas channel inlet through-hole 104) is vertically above the fuel gas channel outlet (fuel gas channel outlet through-hole 105), and the oxidant gas channel inlet (oxidant gas). The channel inlet through-hole 204) is vertically above the outlet of the oxidant gas channel (oxidant gas channel outlet through-hole 205), and vertically above each of the fuel gas channel and the oxidant gas channel. The flow path length of the heading portion is less than 50% of the total flow path length of each gas flow path, specifically, approximately 40%. This facilitates the discharge of water in the gas flow path and makes it possible to obtain an excellent and highly efficient fuel cell.

  The maximum vertical dimension of the cooling medium supply communication hole and the maximum vertical dimension of the cooling medium discharge communication hole are both 80% or more of the maximum vertical dimension of the anode side electrode and the cathode side electrode. It is easy to provide the cooling medium flow path in a region corresponding to most of the electrode area, which is effective in keeping the temperature of the entire fuel cell uniform. . Here, a substantially rectangular electrode (a rectangular shape having the same vertical and horizontal dimensions for both the anode side electrode and the cathode side electrode) is placed horizontally (long side in the horizontal direction). As shown in FIGS. 1 and 3, the width (long side along the vertical direction) of the cooling medium supply communication hole and the cooling medium discharge communication hole is about 85 of the short side (side along the vertical direction) of the electrode. %.

  In addition, for the cooling medium flow path, it is possible to increase the cross-sectional area of the entire flow path, shorten the flow path length, and increase the flow rate of the cooling medium. It is preferable from the viewpoint of restraining. For this reason, the cooling medium flow path is not formed in a bellows shape, but more grooves than the fuel gas flow path and the oxidant gas flow path are provided in a straight line.

  An O-ring gasket is used as a seal member between the fuel gas plate and the oxidant gas plate. This is because it is easy to handle, has excellent workability when assembling a fuel cell, and is suitable for mass production.

  The seal member between the fuel gas plate and the oxidant gas plate seals the periphery of the fuel gas supply communication hole 304a, the fuel gas flow channel inlet through hole 104, and the gas delivery flow channel 106, and the oxidant gas supply communication hole 304b. The periphery of the oxidant gas flow path inlet through-hole 204 and the gas transfer flow path 206 is sealed, and the periphery of the fuel gas flow path outlet through-hole 105, the fuel gas discharge communication hole 305a and the gas transfer flow path 107 is sealed and oxidized. The periphery of the agent gas flow path outlet through-hole 205, the oxidant gas discharge communication hole 305b, and the gas delivery flow path 207 is sealed, and the periphery of the cooling medium supply communication hole 302, the cooling medium discharge communication hole 303, and the cooling medium flow path 301 is sealed. Sealed. In this way, the fuel gas plate and the oxidant gas plate are sealed by the sealing member and overlapped, and are used as a separator integrally.

  Hereinafter, a fuel cell having the above-described separator will be described with reference to FIGS. 7 and 8. FIG. 7 is a schematic view for explaining the laminated structure of the fuel cell, and FIG. 8 is a cross-sectional view for explaining this laminated structure.

  The fuel cell stack includes an MEA and a separator that sandwiches the MEA, and a plurality of these are stacked. The fuel cell stack has a rectangular parallelepiped shape as a whole. Here, the short side direction is oriented in the vertical direction and the long side direction is oriented in the horizontal direction.

  The MEA 501 includes a solid polymer electrolyte membrane 502, and an anode side electrode 503a and a cathode side electrode 503b disposed with the electrolyte membrane interposed therebetween, and each of the anode side electrode and the cathode side electrode includes, for example, a porous material. An anode side gas diffusion layer 504a and a cathode side gas diffusion layer 504b made of porous carbon paper or the like as layers are disposed. The outer shape of the MEA is the same as that of the separator.

  Sheet-like seal members 402 are provided as seal members on both sides of the MEA. As shown in FIG. 6, the sheet-like sealing member has an opening 403 for accommodating the cathode side electrode and the cathode side gas diffusion layer, or for accommodating the anode side electrode and the anode side gas diffusion layer, In addition, there are holes corresponding to the fuel gas supply communication hole, the fuel gas discharge communication hole, the oxidant gas supply communication hole, and the oxidant gas discharge communication hole.

  The MEA and the sheet-like seal member are sandwiched between separators (more specifically, sandwiched between the fuel gas plate 101 and the oxidant gas plate 201).

  Since the solid polymer film forming the MEA is deformed with time, if the sealing member does not follow the MEA deformation, a gas leak may occur between the MEA and the separator, which may cause a decrease in battery performance. . For this reason, gas leak can be prevented for a long period of time by using the sheet-like sealing member which has high adhesiveness with the MEA and is capable of following the aging of the MEA.

  As described above, it is possible to prevent gas leakage for a long period of time by using a sheet-like sealing material that has high adhesion to the MEA between the separator and the MEA and is capable of following the aging of the MEA. . Moreover, the workability | operativity at the time of laminating | stacking can be improved by using an O-ring-like gasket for the seal | sticker of the fuel gas plate and oxidant gas plate which comprise a separator.

  Both the fuel gas plate and the oxidant gas plate can be formed of a known material as a fuel cell separator. The MEA can have a configuration known as an MEA of a fuel cell.

It is a front view which shows the surface which opposes an anode side electrode about an example of a fuel gas plate. It is a front view which shows the surface on the opposite side to the surface which opposes an anode side electrode about an example of a fuel gas plate. It is a front view which shows the surface which opposes a cathode side electrode about an example of an oxidizing agent gas plate. It is a front view which shows the surface on the opposite side to the surface which opposes a cathode side electrode about an example of an oxidizing agent gas plate. It is a front view which shows an example of an O-ring shaped gasket. It is a front view which shows an example of the sealing member on a sheet | seat. It is a schematic diagram for demonstrating a laminated structure about an example of a fuel cell. It is typical sectional drawing for demonstrating a laminated structure about an example of a fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Fuel gas plate 102 Fuel gas flow path 103 Sealing member arrangement | positioning groove | channel 104 Fuel gas flow path inlet through hole 105 Fuel gas flow path outlet through hole 106 Fuel gas inlet side gas delivery flow path 107 Fuel gas outlet side gas delivery flow path 201 Oxidant gas plate 202 Oxidant gas channel 203 Sealing member disposition groove 204 Oxidant gas channel inlet through hole 205 Oxidant gas channel outlet through hole 206 Oxidant gas inlet side gas delivery channel 207 Oxidant gas outlet side Gas delivery flow path 301 Cooling medium flow path 302 Cooling medium supply communication hole 303 Cooling medium discharge communication hole 304a Fuel gas supply communication hole 305a Fuel gas discharge communication hole 304b Oxidant gas supply communication hole 305b Oxidant gas discharge communication hole 401 O-ring Gasket 402 Sheet-like Seal Member 403 Opening 501 MEA (Membrane Electrode Aggregation)
502 solid polymer electrolyte membrane 503a anode side electrode 503b cathode side electrode 504a anode side gas diffusion layer 504b cathode side gas diffusion layer

Claims (10)

In a fuel cell having an electrolyte membrane, a membrane electrode assembly having an anode side electrode and a cathode side electrode arranged across the electrolyte membrane, and a separator sandwiching the membrane electrode assembly,
The separator is a plate member having a fuel gas channel provided on the surface facing the anode side electrode, and a plate member having an oxidant gas channel provided on the surface facing the cathode side electrode And an oxidant gas plate
The surface opposite to the surface facing the anode side electrode of the fuel gas plate and the surface opposite to the surface facing the cathode side electrode of the oxidant gas plate are overlapped via an O-ring gasket,
A fuel cell, wherein a membrane electrode assembly is sandwiched between separators via a sheet-like seal member. The fuel cell according to claim 1, wherein the sheet-like seal member is made of olefin resin, ethylene propylene rubber, fluororesin or fluororubber. The fuel cell according to claim 1 or 2, wherein the O-ring gasket is made of silicone resin or silicone rubber. The inlet of the fuel gas channel is vertically above the outlet of the fuel gas channel,
The inlet of the oxidant gas channel is vertically above the outlet of the oxidant gas channel, and in each of the fuel gas channel and the oxidant gas channel, the channel length of the part directed vertically upward is the respective gas channel. The fuel cell according to any one of claims 1 to 3, which is less than 50% of the total flow path length.   A cooling medium flow path is provided on at least one of a surface opposite to the surface facing the anode side electrode of the fuel gas plate and a surface opposite to the surface facing the cathode side electrode of the oxidant gas plate. The fuel cell according to any one of claims 1 to 4, wherein the fuel cell is formed. The fuel gas channel and the oxidant gas channel are arranged in parallel and / or opposite to each other; and
The fuel cell according to claim 5, wherein the cooling medium flow path is orthogonal to the fuel gas flow path and the oxidant gas flow path. The fuel gas plate is provided with through holes at the inlet end and the outlet end of the fuel gas flow path, respectively, and serves as a fuel gas flow path inlet through hole and a fuel gas flow path outlet through hole,
The oxidant gas plate is provided with through holes at the inlet end and the outlet end of the oxidant gas flow path to form an oxidant gas flow path inlet through hole and an oxidant gas flow path outlet through hole,
Separately from these through holes, the fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging fuel gas in the thickness direction through both gas plates, and the fuel gas supply communication holes and A pair of communication holes for supplying and discharging the oxidant gas in the thickness direction through both gas plates is provided as the fuel gas discharge communication hole, and the oxidant gas supply communication hole and the oxidant gas discharge communication are provided. A hole,
On the surface opposite to the surface facing the anode side electrode of the fuel gas plate, the fuel gas channel inlet through hole and the fuel gas supply communication hole communicate with each other, the fuel gas channel outlet through hole, and the fuel gas discharge. A flow path communicating with the communication hole is formed,
A channel for connecting the oxidant gas flow channel inlet through hole and the oxidant gas supply communication hole to the surface opposite to the surface facing the cathode side electrode of the oxidant gas plate and the oxidant gas flow channel outlet through hole And a flow path that connects the oxidant gas discharge communication hole,
The fuel gas plate and the oxidant gas plate are provided with a pair of communication holes for supplying and discharging the cooling medium in the thickness direction through the gas plates at both ends of the cooling medium flow path. The fuel cell according to claim 5 or 6, wherein the communication hole is a cooling medium discharge communication hole. The channel cross-sectional area of the channel that communicates each through hole and the corresponding communication hole,
The fuel cell according to claim 7, wherein the fuel cell becomes smaller in a direction from the communication hole toward the through hole.   The fuel cell according to claim 7 or 8, wherein the separator is provided along a vertical direction. 10. The maximum vertical dimension of the cooling medium supply communication hole and the maximum vertical dimension of the cooling medium discharge communication hole are each 80% or more of the maximum vertical dimension of the anode side electrode and the cathode side electrode. The fuel cell as described.

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