JP2012094366A - Fuel cell, and fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the durability of a fuel cell.SOLUTION: A fuel cell comprises a membrane electrode assembly having an electrolyte membrane, a first catalyst layer on one side of the electrolyte membrane, and a second catalyst layer on the other side, a first and second gas diffusion layers sandwiching the membrane electrode assembly and adjacent to the first and second catalyst layers, respectively, a gasket at the peripheries of the membrane electrode assembly and the first and second gas diffusion layers, and separator plates sandwiching the gas diffusion layers and the gasket. The gasket enters into the first gas diffusion layer when formed, the periphery of the second gas diffusion layer is disposed at the inner position relative to the periphery of the first gas diffusion layer, and a clearance is formed between the second gas diffusion layer and the gasket.

Description

  The present invention relates to a fuel cell.

  The electrode membrane assembly is disposed on the bottom surface of the U-shaped cross section of the first separator so as to secure a predetermined gap with respect to the inner wall surface of the flange portion, and the second separator is positioned on the electrode membrane assembly. The sealing agent applies a predetermined pressure to the second separator from the outside in the stacking direction, and maintains the pressed state, while the electrode membrane assembly and the end portion of the second separator and the flange portion. There is known a fuel cell filled and cured in the gap (for example, Patent Document 1).

JP 2005-339891 A

  However, the conventional technology has a problem that a gap is easily generated in the seal portion, stress is easily generated in the electrolyte membrane when the pressure of the reaction gas fluctuates, and the durability of the fuel cell is difficult to obtain.

  The present invention has been made to solve at least a part of the above-described problems, and an object thereof is to improve the durability of a fuel cell.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A fuel cell, a membrane electrode assembly comprising an electrolyte membrane, a first catalyst layer formed on one surface of the electrolyte membrane, and a second catalyst layer formed on the other surface; Two gas diffusion layers sandwiching the membrane electrode assembly, the first and second gas diffusion layers adjacent to the first and second catalyst layers, respectively, the membrane electrode assembly and the first A gasket formed on an outer edge of the second gas diffusion layer, a separator plate sandwiching the two gas diffusion layers and the gasket, and the gasket is disposed on the first gas diffusion layer. The fuel cell is formed so as to penetrate, and an outer edge of the second gas diffusion layer is formed inside an outer edge of the first gas diffusion layer.
According to this application example, the gasket is formed so as to penetrate into the first gas diffusion layer. Therefore, even if there is a difference in pressure between the first and second gas diffusion layers, the gasket is applied to the electrolyte membrane. It is possible to suppress the stress and improve the durability of the fuel cell.

[Application Example 2]
In the fuel cell according to Application Example 1, an outer edge of the second catalyst layer is formed inside an outer edge of the electrolyte membrane, and an outer edge of the second gas diffusion layer is an outer edge of the second catalyst layer. A portion of the electrolyte membrane not covered with the second catalyst layer and a contact portion between the gasket and a contact portion between the gasket and the separator plate are: The fuel cell is sealed with a sealing material.
According to this application example, it is possible to improve the durability of the fuel cell and suppress the leakage of the reaction gas.

[Application Example 3]
The fuel cell according to Application Example 1 or Application Example 2, wherein the first catalyst layer is a cathode catalyst layer, and the second catalyst layer is an anode catalyst layer.
According to this application example, the anode catalyst layer (anode side) may be at a higher pressure.

[Application Example 4]
A fuel cell system, wherein the fuel cell according to any one of application examples 1 to 3, a fuel tank for supplying fuel gas to the fuel cell, the fuel tank, and the fuel cell A fuel gas supply pipe, a pressure adjusting valve provided in the fuel gas supply pipe, an air compressor for compressing and supplying air to the fuel tank, the air compressor, and the fuel cell. An oxidant gas supply pipe to be connected; and a fuel cell control unit, wherein the fuel cell control unit controls the operation of the pressure regulating valve and the air compressor during power generation of the fuel cell. A fuel cell system that adjusts the pressure applied to the second catalyst layer to be equal to or higher than the pressure applied to the first catalyst layer.
According to this application example, it is possible to increase the pressure on the anode side during power generation of the fuel cell.

[Application Example 5]
In the fuel cell system according to Application Example 4, the oxidizing gas supply valve provided in the oxidizing gas supply pipe, the fuel exhaust pipe for discharging the fuel exhaust gas from the fuel cell, and the fuel exhaust pipe A fuel exhaust valve provided; an oxidation exhaust gas pipe for discharging the oxidation exhaust gas from the fuel cell; an oxidation exhaust gas valve provided in the oxidation exhaust gas pipe; the fuel gas supply pipe; and the oxidation gas supply pipe; A pressure regulator connected between the pressure regulator and at least one of the pressure regulator connected between the fuel gas exhaust pipe and the oxidizing gas exhaust pipe, and the fuel cell. The control unit adjusts the pressure applied to the second catalyst layer to be equal to or higher than the pressure applied to the first catalyst layer by using the pressure adjusting device when the fuel cell is not generating power. Stem.
According to this application example, the pressure on the anode side and the cathode side can be adjusted by the pressure adjusting device.

  The present invention can be realized in various forms. For example, in addition to a fuel cell, the present invention can be realized in various forms such as a fuel cell system.

It is explanatory drawing which shows the fuel cell system of a 1st Example. 3 is an explanatory diagram showing a schematic configuration of a power generation unit 110. FIG. It is explanatory drawing which shows the structure of the fuel cell of a comparative example. It is another comparative example. It is explanatory drawing which shows an example of a structure of the pressure regulator. It is explanatory drawing which shows the time change of the pressure by the side of the anode side of a fuel cell. It is explanatory drawing which shows a 2nd Example. It is explanatory drawing which shows the operation | movement in a 2nd Example.

[First embodiment]
FIG. 1 is an explanatory diagram showing a fuel cell system according to a first embodiment. The fuel cell system 10 includes a fuel cell 100, a fuel tank 200, an air pump 300, a control unit 400, a pressure adjusting device 500, and pressure gauges 250 and 350. The fuel cell 100 is a device that generates electric power by reacting a fuel gas and an oxidizing gas. The fuel cell 100 includes a plurality of power generation units 110 and an end plate 190. The plurality of power generation units 110 are stacked and the end plates 190 are disposed at both ends of the stacked power generation units 110 in the stacking direction.

  The fuel tank 200 stores fuel gas supplied to the fuel cell 100. In this embodiment, hydrogen is used as the fuel gas. The fuel tank 200 and the fuel cell 100 are connected by a fuel gas supply pipe 210. A pressure regulating valve 230 for adjusting the pressure of the fuel gas supplied to the fuel cell 100 is disposed in the fuel gas supply pipe 210. The pressure regulating valve 230 adjusts the pressure of the fuel gas supplied to the fuel cell 100 during the power generation operation of the fuel cell 100. On the other hand, when the power generation of the fuel cell 100 is stopped, the supply of the fuel gas from the fuel tank 200 to the fuel cell 100 is stopped by closing. A main stop valve is provided between the pressure regulating valve 230 and the fuel tank 200, and the pressure regulating valve 230 only adjusts the pressure of the fuel gas supplied to the fuel cell 100. A configuration may be adopted in which the supply of the fuel gas from the fuel tank 200 to the fuel cell 100 is stopped during the stop. A fuel gas exhaust pipe 220 for releasing the fuel exhaust gas to the atmosphere is disposed downstream of the fuel cell 100, and a fuel gas exhaust valve 240 is provided in the fuel gas exhaust pipe 220. The fuel gas exhaust valve 240 is closed in order to suppress the backflow of air from the atmosphere while the fuel cell 100 stops generating power. The pressure gauge 250 is provided on the fuel gas exhaust pipe 220 and measures the pressure of the fuel gas. The pressure gauge 250 may be provided on the fuel gas supply pipe 210.

  The air pump 300 compresses the air supplied from the fuel cell 100. That is, in this embodiment, air (oxygen in the air) is used as the oxidizing gas. The air pump 300 and the fuel cell 100 are connected by an oxidizing gas supply pipe 310. The oxidizing gas supply pipe 310 is provided with an oxidizing gas main stop valve 330 for restricting the movement of air between the fuel cell 100 and the air pump 300 when the fuel cell 100 stops generating power. The oxidizing gas supply pipe 310 may be provided with an intercooler for cooling the oxidizing gas that has become a high temperature due to compression by the air pump 300. On the downstream side of the fuel cell 100, an oxidizing gas exhaust pipe 320 for releasing the oxidizing exhaust gas to the atmosphere is arranged, and the oxidizing gas exhaust pipe 320 is provided with an oxidizing gas exhaust valve 340. The oxidizing gas exhaust valve 340 is closed in order to suppress the backflow of air from the atmosphere while the fuel cell 100 stops generating power. The pressure gauge 350 is provided on the oxidizing gas exhaust pipe 320 and measures the pressure of the oxidizing gas. The pressure gauge 350 may be provided on the oxidizing gas supply pipe 310.

  The pressure adjusting device 500 is connected to the fuel gas exhaust pipe 220 closer to the fuel cell 100 than the fuel gas exhaust valve 240 and the oxidizing gas exhaust pipe 320 closer to the fuel cell 100 than the oxidizing gas exhaust valve 340. The pressure adjusting device 500 adjusts the pressure of the fuel gas and the oxidizing gas in the fuel cell 100 while the power generation of the fuel cell 100 is stopped. The configuration of the pressure adjusting device 500 will be described later. The pressure adjusting device 500 is connected to the fuel gas supply pipe 210 on the fuel cell 100 side from the pressure regulating valve 230 and the oxidizing gas supply pipe 310 on the fuel cell 100 side from the oxidizing gas main stop valve 330. Also good.

  The control unit 400 includes a pressure regulating valve 230, a fuel gas exhaust valve 240, an air pump 300, an oxidizing gas main stop valve 330, an oxidizing gas exhaust valve 340, a pressure regulator 500, and pressure gauges 250 and 350. Connected and controls these operations. Specifically, during the power generation operation of the fuel cell 100, the control unit 400 operates the air pump 300, the pressure regulating valve 230, and the oxidizing gas so that the pressure of the fuel gas becomes larger than the pressure of the oxidizing gas. The opening degree of the main stop valve 330, the fuel gas exhaust valve 240, and the oxidizing gas exhaust valve 340 is controlled. In addition, while the power generation of the fuel cell 100 is stopped, the control unit 400 stops the operation of the air pump 300, and the pressure regulating valve 230, the fuel gas exhaust valve 240, the oxidizing gas main stop valve 330, and the oxidizing gas exhaust valve 340. , And the pressure adjusting device 500 is used to adjust the pressure of the fuel gas to be larger than the pressure of the oxidizing gas.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the power generation unit 110. The power generation unit 110 includes a membrane electrode assembly 120, a cathode gas diffusion layer 132, an anode gas diffusion layer 133, a cathode separator plate 142, an anode separator plate 143, and a gasket 160. The membrane electrode assembly 120 includes an electrolyte membrane 121, a cathode catalyst layer 122, and an anode catalyst layer 123.

  The electrolyte membrane 121 is a proton conductive ion exchange membrane made of a solid polymer material, for example, a fluorine-based resin such as perfluorocarbon sulfonic acid polymer. The cathode catalyst layer 122 and the anode catalyst layer 123 include a catalyst that promotes an electrochemical reaction, such as a platinum catalyst or a platinum alloy catalyst made of platinum and another metal. The cathode catalyst layer 122 is formed on one surface of the electrolyte membrane 121, and the anode catalyst layer 123 is formed on the other surface of the electrolyte membrane 121. In this embodiment, the outer edge of the cathode catalyst layer 122 substantially coincides with the outer edge of the electrolyte membrane 121, but the outer edge of the anode catalyst layer 123 is located inside the outer edge of the electrolyte membrane 121.

  The cathode gas diffusion layer 132 and the anode gas diffusion layer 133 are members for allowing the fuel gas and the oxidation gas to pass therethrough and diffusing these gases and supplying them to the cathode catalyst layer 122 and the anode catalyst layer 123, respectively. Alternatively, a porous body formed of a metal such as titanium or a conductive resin can be used. Further, as the cathode gas diffusion layer 132 and the anode gas diffusion layer 133, carbon cloth or carbon paper using a carbon nonwoven fabric may be used.

  The cathode gas diffusion layer 132 is disposed in contact with the cathode catalyst layer 122. Here, the outer edge of the cathode gas diffusion layer 132 is located slightly inside the outer edge of the cathode catalyst layer 122. However, the outer edge of the cathode gas diffusion layer 132 and the outer edge of the cathode catalyst layer 122 may be substantially the same. The anode gas diffusion layer 133 is disposed in contact with the anode catalyst layer 123. Here, the outer edge of the anode gas diffusion layer 133 is located inside the outer edge of the anode catalyst layer 123. The outer edge of the anode gas diffusion layer 133 is located inside the outer edge of the cathode gas diffusion layer 132.

  The cathode separator plate 142 is a metal plate-shaped member, and is disposed so as to be in contact with the cathode gas diffusion layer 132. The cathode separator plate 142 has a groove 144 on the surface in contact with the cathode gas diffusion layer 132, and the groove 144 forms an oxidizing gas flow path 152. The anode separator plate 143 is a metal plate-shaped member, and is disposed in contact with the anode gas diffusion layer 133. The anode separator plate 143 has a groove 145 on the surface in contact with the anode gas diffusion layer 133, and the groove 145 forms a fuel gas flow path 153.

  The gasket 160 is formed so as to surround the outer edges of the membrane electrode assembly 120, the cathode gas diffusion layer 132, and the anode gas diffusion layer 133 in a frame shape. The gasket 160 is formed by injection molding a resin material. Here, since the outer edge of the anode gas diffusion layer 133 is located inside the outer edge of the cathode gas diffusion layer 132, the resin constituting the gasket 160 is the cathode gas diffusion layer 132 when the gasket 160 is formed by injection. Invade into the hole. Therefore, no gap (176) is generated between the membrane electrode assembly 120 and the cathode separator plate 142. On the other hand, the resin constituting the gasket 160 does not reach the anode gas diffusion layer 133 when the gasket 160 is formed by injection, and a gap 177 is generated between the gasket 160 and the anode gas diffusion layer 133.

  A seal surface 172 is formed at the boundary between the gasket 160 and the cathode separator plate 142, and a seal surface 173 is formed at the boundary between the gasket 160 and the anode separator plate 143, and the gasket 160 and the membrane electrode assembly 120 A seal surface 175 is formed at the boundary with the anode side surface of the electrolyte membrane 121. These sealing surfaces suppress leakage of fuel gas and oxidizing gas.

  In the fuel cell of this embodiment, the control unit (FIG. 1) sets the pressure of the fuel gas to be equal to or higher than the pressure of the oxidizing gas. Due to the pressure difference between the fuel gas and the oxidizing gas, a force acts on the electrolyte membrane 121 in the direction from the anode side (fuel gas flow path side) to the cathode side (oxidizing gas flow path side). Here, in this embodiment, the cathode gas diffusion layer 132 and the gasket 160 are present on the cathode side of the electrolyte membrane 121, and the resin constituting the gasket 160 penetrates into the cathode gas diffusion layer 132. There is no gap (176 (see FIG. 3 described later)) between the gas diffusion layer 132 and the gasket 160. As a result, even if a force is applied to the electrolyte membrane 121 in the direction from the anode side to the cathode side, the electrolyte membrane 121 is supported by the cathode gas diffusion layer 132 and the gasket 160, and therefore is not easily deformed and hardly deteriorated.

  FIG. 3 is an explanatory diagram showing a configuration of a fuel cell of a comparative example. In the comparative example, the outer edge of the cathode gas diffusion layer 132 and the outer edge of the anode gas diffusion layer 133 are both located inside the outer edge of the membrane electrode assembly 120. The gasket 160 does not penetrate the cathode gas diffusion layer 132 and the anode gas diffusion layer 133. That is, a gap 176 is formed between the cathode gas diffusion layer 132 and the gasket 160, and a gap 177 is formed between the anode gas diffusion layer 133 and the gasket 160.

  FIG. 3A shows the case where the pressure of the fuel gas is the same as the pressure of the oxidizing gas, and FIG. 3B shows the case where the pressure of the fuel gas is larger than the pressure of the oxidizing gas. When the pressure of the fuel gas and the pressure of the oxidizing gas are the same, the force applied to the electrolyte membrane 121 from the anode side is the same as the force applied to the electrolyte membrane 121 from the cathode side, and as shown in FIG. In addition, the electrolyte membrane 121 is not deformed. However, when the pressure of the fuel gas is higher than the pressure of the oxidizing gas, the force applied to the electrolyte membrane from the anode side is larger than the force applied to the electrolyte membrane 121 from the cathode side. At positions 176 and 177, deformation occurs so as to be convex toward the cathode side. When the state shown in FIG. 3A and the state shown in FIG. 3B are repeated, the electrolyte membrane 121 deteriorates due to fatigue, and the durability decreases.

  FIG. 4 shows another comparative example. In this comparative example, the outer edges of the cathode catalyst layer 122 and the anode catalyst layer 123 are substantially the same as the outer edges of the electrolyte membrane 121, and the outer edge of the cathode gas diffusion layer 132 and the outer edge of the anode gas diffusion layer 133 are both membranes. It is located slightly inside the outer edge of the electrode assembly 120. The gasket 160 penetrates both the cathode gas diffusion layer 132 and the anode gas diffusion layer 133. In this configuration, the seal surface (176 (see FIG. 3)) is not formed on the boundary surface between the gasket 160 and the cathode catalyst layer 122, and the seal surface (177 (FIG. 3) is formed on the boundary surface between the gasket 160 and the anode catalyst layer 123. See)) is not formed. Therefore, there arises a problem that it is difficult to suppress leakage of fuel gas and oxidizing gas.

  In this embodiment, the gasket 160 is formed so as to enter the cathode gas diffusion layer 132, and the outer edge of the anode gas diffusion layer 133 is formed inside the outer edge of the cathode gas diffusion layer 132. By adopting a configuration in which a gap 177 is formed between the diffusion layer 133 and the gasket 160, the problem of the comparative example is solved, and fuel gas and oxidizing gas are sealed, and the durability of the electrolyte membrane 121 is improved. Can be improved.

  Next, the operation of the fuel cell according to the first embodiment while power generation is stopped will be described. FIG. 5 is an explanatory diagram showing an example of the configuration of the pressure adjusting device 500. The pressure adjustment device 500 includes a piston plate 510, an actuator 520, and a guide rail 525. The piston plate 510 separates the inside of the pressure adjustment device 500 into a first chamber 501 and a second chamber 502. The first chamber 501 is connected to the fuel gas exhaust pipe 220 by a connecting pipe 221, and the second chamber 502 is connected to the oxidizing gas exhaust pipe 320 by a connecting pipe 321. The actuator 520 moves the piston plate 510 along the guide rail 525. Thereby, the size of the first chamber 501 and the second chamber 502 can be changed.

  FIG. 6 is an explanatory diagram showing the change over time in pressure on the anode side and cathode side of the fuel cell. These pressures can be measured by pressure gauges 250 and 350. At time t0, the control unit 400 stops the power generation of the fuel cell 100, and closes the pressure regulating valve 230, the fuel gas exhaust valve 240, the oxidizing gas main stop valve 330, and the oxidizing gas exhaust valve 340. At this time, the pressure regulating valve 230 may be closed after the oxidizing gas main stop valve 330 is closed. Since hydrogen has a high gas permeability to the electrolyte membrane 121, the pressure on the anode side decreases and the pressure on the cathode side increases. At time t1, control unit 400 moves piston plate 510 to narrow first chamber 501 and widen second chamber 502. As a result, the volume of the gas flow path on the anode side (volume of the fuel gas supply pipe 210 + volume of the fuel gas exhaust pipe 220 + volume of the fuel gas flow path 153 (FIG. 3) + volume of the first chamber 501) is reduced. Since the volume of the cathode-side gas flow path (the volume of the oxidizing gas supply pipe 310 + the volume of the oxidizing gas exhaust pipe 320 + the volume of the oxidizing gas flow path 152 (FIG. 3) + the volume of the second chamber 502) increases. The pressure on the anode side increases and the pressure on the cathode side decreases.

  As described above, according to this embodiment, the control unit 400 moves the piston plate 510 so that the first chamber 501 is narrowed and the second chamber 502 is widened with respect to the pressure adjusting device 500. As a result, the pressure on the anode side is increased and the pressure on the cathode side is decreased. As a result, the pressure difference between the anode side and the cathode side can be reduced while the power generation of the fuel cell 100 is stopped, so that the stress applied to the electrolyte membrane 121 can be reduced and the durability of the fuel cell 100 can be improved.

[Second Embodiment]
FIG. 7 is an explanatory diagram showing the second embodiment. The fuel gas exhaust valve 240 and the oxidizing gas exhaust valve 340 of the first embodiment are two-way valves, but the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341 of the second embodiment are three-way valves. Is different. The pressure adjusting device 530 is connected to one of the three valve ports of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341.

  FIG. 8 is an explanatory diagram showing the operation in the second embodiment. FIG. 8A shows the time when the fuel cell 100 is generating power, and FIG. 8B shows the state after the fuel cell 100 generates power. The pressure adjustment device 530 includes a soft film 540 that does not allow gas to pass therethrough, and the film 540 separates the inside of the pressure adjustment device 530 into a first chamber 531 and a second chamber 532. The film 540 has a little play and is stretched gently. The first chamber 531 is connected to the fuel gas exhaust valve 241, and the second chamber 532 is connected to the oxidizing gas exhaust valve 342.

  During power generation by the fuel cell 100, the control unit 400 opens the three sides of the fuel gas exhaust valve 241 to allow communication between the fuel cell 100 and the atmosphere, and between the fuel gas exhaust pipe 220 and the first chamber 531. To communicate. Similarly, the control unit 400 opens the three sides of the oxidizing gas exhaust valve 341 to allow communication between the fuel cell 100 and the atmosphere, and also allows communication between the oxidizing gas exhaust pipe 320 and the second chamber 532. As a result, since the pressures in the first chamber 531 and the second chamber 532 are substantially the same, the film 540 is in a slack state.

  The control unit 400 closes the pressure regulating valve 230 and the oxidizing gas main stop valve 330 when the fuel cell 100 is brought into a non-power generation state. At this time, the oxidizing gas main stop valve 330 may be closed first, and then the pressure regulating valve 230 may be closed. In this way, it is possible to increase the pressure on the anode side. Next, the control unit 400 causes the fuel gas exhaust valve 241 to close the valve on the atmosphere side. Thereby, the communication between the fuel cell 100 and the first chamber 531 is maintained. Further, the control unit 400 causes the oxidizing gas exhaust valve 341 to close the valve on the atmosphere side. Thereby, the communication between the fuel cell 100 and the second chamber 532 is maintained.

  Since hydrogen has a high gas permeability to the electrolyte membrane 121, the hydrogen moves from the anode side to the cathode side through the electrolyte membrane 121. As a result, the amount of gas on the cathode side increases, and the pressure on the cathode side increases. In this embodiment, the force due to the pressure difference between the anode and the cathode is applied not to the electrolyte membrane 121 but to the film 540. That is, when the film 540 swells to the anode side, the stress applied to the electrolyte membrane 121 can be reduced and the durability of the fuel cell 100 can be improved.

  The controller 400 may change the opening / closing operation of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341 from the operation described above. FIG. 8C is an explanatory diagram showing different operations of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341. At the timing when the fuel cell 100 is switched from power generation stop to power generation, the pressure regulator 530 has a negative pressure. In this operation, the control unit 400 causes the fuel gas exhaust valve 241 to communicate between the fuel cell 100 and the atmosphere during power generation of the fuel cell 100, and does not connect the fuel gas exhaust pipe 220 and the first chamber 531. Keep in communication. Similarly, the control unit 400 causes the oxidant gas exhaust valve 341 to communicate between the fuel cell 100 and the atmosphere, and causes the oxidant gas exhaust pipe 320 and the second chamber 532 to be disconnected. Thereby, the negative pressure inside the pressure adjusting device 530 can be maintained.

  The control unit 400 once opens the three sides of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341 at the timing when the fuel cell 100 is shifted from power generation to stop. That is, the controller 400 temporarily changes the state of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341 to the state shown in FIG. Thereafter, the control unit 400 changes the state of the fuel gas exhaust valve 241 and the oxidizing gas exhaust valve 341 to the state shown in FIG. In this way, when the state shifts to the state shown in FIG. 8A, the pressure in the first chamber 531 and the second chamber 532 can be made substantially the same, and the film 540 can be in a slack state. Thereafter, the operation when transitioning to the state shown in FIG. 8B is the same as the operation described in the second embodiment. Therefore, also in this embodiment, similarly, the stress applied to the electrolyte membrane 121 can be reduced and the durability of the fuel cell 100 can be improved.

  As described above, according to the present embodiment, when the fuel cell 100 is not generating power, the film 540 swells to the anode side, thereby reducing the stress applied to the electrolyte membrane 121, so that the durability of the fuel cell 100 can be improved. it can.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 100 ... Fuel cell 110 ... Power generation unit 120 ... Membrane electrode assembly 121 ... Electrolyte membrane 122 ... Cathode catalyst layer 123 ... Anode catalyst layer 132 ... Cathode gas diffusion layer 133 ... Anode gas diffusion layer 142 ... Cathode separator plate 143... Anode separator plate 144... Groove 145. Fuel tank 210 ... Fuel gas supply pipe 220 ... Fuel gas exhaust pipe 221 ... Connection pipe 230 ... Pressure regulating valve 240 ... Fuel gas exhaust valve 241 ... Fuel gas exhaust valve 250 ... Pressure gauge 300 ... Air pump 310 ... Oxidizing gas supply pipe 320 ... Oxidation Gas exhaust pipe 32 ... Connection pipe 330 ... Oxidation gas main stop valve 340 ... Oxidation gas exhaust valve 341 ... Oxidation gas exhaust valve 342 ... Oxidation gas exhaust valve 350 ... Pressure gauge 400 ... Controller 500 ... Pressure regulator 501 ... First chamber 502 ... Chamber 510 ... Piston plate 520 ... Actuator 525 ... Guide rail 530 ... Pressure adjusting device 531 ... First chamber 532 ... Second chamber 540 ... Film

Claims (5)

A fuel cell,
A membrane electrode assembly having an electrolyte membrane, a first catalyst layer formed on one surface of the electrolyte membrane, and a second catalyst layer formed on the other surface;
Two gas diffusion layers sandwiching the membrane electrode assembly, the first and second gas diffusion layers respectively adjacent to the first and second catalyst layers;
A gasket formed on an outer edge of the membrane electrode assembly and the first and second gas diffusion layers;
A separator plate sandwiching the two gas diffusion layers and the gasket;
With
The gasket is formed so as to penetrate the first gas diffusion layer;
The outer edge of the second gas diffusion layer is formed inside the outer edge of the first gas diffusion layer,
Fuel cell. The fuel cell according to claim 1, wherein
The outer edge of the second catalyst layer is formed inside the outer edge of the electrolyte membrane,
The outer edge of the second gas diffusion layer is formed inside the outer edge of the second catalyst layer,
A portion of the electrolyte membrane not covered with the second catalyst layer, a contact portion between the gasket, and a contact portion between the gasket and the separator plate are sealed with a sealing material,
Fuel cell. The fuel cell according to claim 1 or 2,
The fuel cell, wherein the first catalyst layer is a cathode catalyst layer and the second catalyst layer is an anode catalyst layer. A fuel cell system,
The fuel cell according to any one of claims 1 to 3,
A fuel tank for supplying fuel gas to the fuel cell;
A fuel gas supply pipe connecting the fuel tank and the fuel cell;
A pressure regulating valve provided in the fuel gas supply pipe;
An air compressor for compressing and supplying air to the fuel tank;
An oxidizing gas supply pipe connecting the air compressor and the fuel cell;
A fuel cell control unit;
With
The fuel cell control unit controls the operation of the pressure regulating valve and the air compressor during power generation of the fuel cell so that the pressure applied to the second catalyst layer is applied to the first catalyst layer. A fuel cell system that is adjusted to achieve the above. The fuel cell system according to claim 4, further comprising:
An oxidizing gas supply valve provided in the oxidizing gas supply pipe;
A fuel exhaust pipe for discharging the fuel exhaust gas from the fuel cell;
A fuel exhaust valve provided in the fuel exhaust pipe;
An oxidation exhaust gas pipe for discharging the oxidation exhaust gas from the fuel cell;
An oxidation exhaust gas valve provided in the oxidation exhaust gas pipe;
At least one of a pressure regulator connected between the fuel gas supply pipe and the oxidant gas supply pipe, and a pressure regulator connected between the fuel gas exhaust pipe and the oxidant gas exhaust pipe A pressure regulator of
With
The fuel cell control unit adjusts the pressure applied to the second catalyst layer to be equal to or higher than the pressure applied to the first catalyst layer by using the pressure adjusting device when the fuel cell is not generating electricity; Fuel cell system.

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