JP2007214049A - Fuel cell, its manufacturing method, and its cooling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of displaying superior durability. <P>SOLUTION: This fuel cell has a membrane electrode assembly 110, separators 140, 160 having groove parts 144, 154, 159, 164, a fist passage 168 to circulate a first cooling medium, and a first seal members 180, 182 disposed in the periphery parts of the separators 140, 160. The first seal members 180, 182 are disposed on the second surfaces 141, 161 located on the reverse sides of first surfaces 151, 171 facing the first passage 168 in the separators 140, 160, and is aligned with the first passage 168. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell, a fuel cell manufacturing method, and a fuel cell cooling method.

The fuel cell has a membrane electrode assembly, a separator and a seal member disposed on both sides of the membrane electrode assembly, and the seal member is disposed on the outer periphery of the separator to leak fuel, an oxidant, and a cooling medium. Is applied in order to suppress (for example, refer to Patent Document 1).
JP 2001-357861 A

  However, since the temperature of the sealing member is increased by heat generated during power generation, causing thermal deterioration, there is a problem in the durability of the fuel cell.

  The present invention has been made in order to solve the problems associated with the prior art described above, and is a fuel cell capable of exhibiting good durability, a method for producing a fuel cell capable of exhibiting good durability, and a fuel cell. It aims at providing the cooling method for exhibiting the favorable durability of this.

In order to achieve the above object, the invention described in claim 1
Membrane electrode assembly,
A separator having a groove,
A first flow path for circulating the first cooling medium; and
A first seal member disposed on the outer periphery of the separator;
The first seal member is disposed on a second surface of the separator that is opposite to the first surface facing the first flow path, and is aligned with the first flow path. This is a fuel cell.

In order to achieve the above object, the invention according to claim 11 provides:
A method of manufacturing a fuel cell having a membrane electrode assembly, a separator having a groove, a first flow path for circulating a first cooling medium, a first seal member, and a second seal member,
The first seal member is disposed in alignment with the first flow path on a second surface located on the opposite side of the first surface facing the first flow path in the outer peripheral portion of the separator,
The second seal member is made of a thermosetting liquid adhesive, is disposed on the first surface of the outer periphery of the separator, and is offset from the outside of the first seal member,
Bringing the first surface of the separator into contact with the first surface of the adjacent separator;
The fuel cell manufacturing method is characterized in that the first surface of the separator is bonded to the first surface of the adjacent separator by curing the second seal member by hot pressing.

In order to achieve the above object, the invention according to claim 15 provides:
A method of manufacturing a fuel cell having a membrane electrode assembly, a separator having a groove, a first flow path for circulating a first cooling medium, a first seal member, and a second seal member,
The first seal member is made of a thermosetting liquid adhesive, and on the second surface located on the opposite side of the first surface facing the first flow channel in the outer periphery of the separator, Aligned and placed
The second seal member is disposed on the first surface of the outer peripheral portion of the separator, and is offset and positioned outside the first seal member;
The membrane electrode assembly has an electrolyte membrane disposed on the second surface of the separator and exposed,
A method of manufacturing a fuel cell, comprising: curing the first seal member by hot pressing to bond the second surface of the separator and the electrolyte membrane from which the membrane electrode assembly is exposed. It is.

In order to achieve the above object, the invention described in claim 19 provides:
A fuel cell cooling method comprising:
The fuel cell
Membrane electrode assembly,
A separator having a groove,
A first flow path for circulating the first cooling medium; and
A first seal member disposed on the outer periphery of the separator;
The first seal member is disposed on a second surface of the separator located on the opposite side of the first surface facing the first flow path, and is aligned with the first flow path;
The fuel cell cooling method is characterized in that the first seal member that is heated by heat generated during power generation is cooled by circulating a first cooling medium through the first flow path.

  According to the first aspect of the present invention, the first surface located on the opposite side of the second surface on which the first seal member is disposed faces the first flow path. Therefore, when the first cooling medium is circulated through the first flow path, the durability of the fuel cell is improved by cooling the first seal member that is heated by heat generated during power generation and suppressing thermal degradation. It is possible. That is, a fuel cell that can exhibit good durability can be provided.

  According to the eleventh aspect of the present invention, since the second seal member made of the thermosetting liquid adhesive is arranged offset from the first seal member, the heat between the second seal member and the hot press is set. The influence of the first seal member on the conductivity is suppressed. Accordingly, the curing time of the second seal member is shortened. Further, in the manufactured fuel cell, the first surface located on the opposite side of the second surface on which the first seal member is disposed faces the first flow path. Therefore, when the first cooling medium is circulated through the first flow path, the durability of the fuel cell is improved by cooling the first seal member that is heated by heat generated during power generation and suppressing thermal degradation. It is possible. That is, it is possible to provide a method for manufacturing a fuel cell that can exhibit good durability.

  According to the fifteenth aspect of the present invention, since the first seal member made of the thermosetting liquid adhesive is arranged offset from the second seal member, the heat between the first seal member and the hot press is set. The influence of the second seal member on the conductivity is suppressed. Accordingly, the curing time of the first seal member is shortened. In addition, since the electrolyte membrane of the membrane electrode assembly is bonded to the separator, the number of components at the time of stacking is reduced. Furthermore, in the manufactured fuel cell, the first surface located on the opposite side of the second surface on which the first seal member is disposed faces the first flow path. Therefore, when the first cooling medium is circulated through the first flow path, the durability of the fuel cell is improved by cooling the first seal member that is heated by heat generated during power generation and suppressing thermal degradation. It is possible. That is, it is possible to provide a method for manufacturing a fuel cell that can exhibit good durability.

  According to the nineteenth aspect of the invention, the first seal member that is heated by the heat generated during power generation is cooled by circulating the first cooling medium through the first flow path. Therefore, thermal degradation of the first seal member is suppressed, and the durability of the fuel cell is improved. That is, it is possible to provide a cooling method for exhibiting good durability of the fuel cell.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view for explaining a fuel cell according to Embodiment 1, and FIGS. 2 and 3 are an exploded view and a sectional view for explaining the structure of the single fuel cell of FIG.

  The fuel cell 10 includes a stack unit 20 in which a plurality of single fuel cell cells 100 are stacked, and is used as a power source. Applications of the power source include, for example, stationary devices, consumer portable devices such as mobile phones, emergency devices, outdoor devices such as leisure and construction power sources, and mobile objects such as automobiles with limited mounting space. In particular, the mobile power supply is preferably applied because a high output voltage is required after a relatively long period of shutdown.

  As will be described later, the fuel cell 10 can cool the first seal members 180 and 182 (see FIG. 3) that rise in temperature due to heat generated during power generation to suppress thermal degradation. The battery 10 has good durability.

  On both sides of the stack part 20, current collecting plates 30, 40, insulating plates 50, 60 and end plates 70, 80 are arranged. The current collecting plates 30 and 40 are made of a gas impermeable conductive member such as dense carbon or copper plate, and are provided with output terminals 35 and 45 for outputting the electromotive force generated in the stack portion 20. . The insulating plates 50 and 60 are formed from an insulating member such as rubber or resin.

  The end plates 70 and 80 are made of a material having rigidity, for example, a metal material such as steel. The end plate 70 is provided with a fuel gas inlet 71, a fuel gas outlet 72, an oxidant in order to circulate a fuel gas (eg, hydrogen), an oxidant gas (eg, oxygen), and a cooling medium (eg, cooling water). It has a gas inlet 74, an oxidant gas outlet 75, a refrigerant inlet 76, and a refrigerant outlet 78.

  Through holes through which the tie rods 90 are inserted are arranged at the four corners of the stack unit 20, current collecting plates 30 and 40, insulating plates 50 and 60, and end plates 70 and 80. The tie rod 90 is fastened with the fuel cell 10 by a nut (not shown) being screwed into a male screw portion formed at the end thereof. The load for forming the stack acts in the stacking direction of the fuel cell single cells 100 to hold the fuel cell single cells 100 in a pressed state.

  The tie rod 90 is formed of a material having rigidity, for example, a metal material such as steel, and has a surface portion that is insulated in order to prevent an electrical short circuit between the fuel cell single cells 100. The number of tie rods 90 installed is not limited to four (four corners). The fastening mechanism of the tie rod 90 is not limited to screwing, and other means can be applied.

  As shown in FIGS. 2 and 3, the fuel cell unit cell 100 includes a membrane electrode assembly (MEA) 110, a first separator 140, a second separator 160, first seal members 180, 182, And it has the 2nd seal member 185. In FIG. 2, the groove portions 144, 154, 164, the first and second seal members 180, 182, 185 and the gaskets 132, 137 of the first and second separators 140, 160 are omitted.

  The membrane electrode assembly 110 includes an electrolyte membrane 120, a cathode electrode (air electrode) 130 and an anode electrode (fuel electrode) 135 disposed between the electrolyte membrane 120, and gaskets 132 and 137.

  The electrolyte membrane 120 is a proton conductive ion exchange membrane formed of a solid polymer material, for example, a fluorine-based resin, and exhibits good electrical conductivity in a wet state. The thickness of the electrolyte membrane 120 is set in consideration of strength during film formation, durability during operation, and output characteristics during operation.

  The cathode electrode 130 is disposed on one surface of the electrolyte membrane 120 and has a cathode catalyst layer and a gas diffusion layer. The anode electrode 135 is disposed on the other surface of the electrolyte membrane 120 and has an anode catalyst layer and a gas diffusion layer.

  The cathode catalyst layer and the anode catalyst layer include an electrode catalyst in which a catalyst component is supported on a conductive support, and a polymer electrolyte. The conductive support of the electrode catalyst is not particularly limited as long as it has a specific surface area for supporting the catalyst component in a desired dispersed state and sufficient electronic conductivity as a current collector, but the main component is carbon. Particles are preferred.

  The catalyst component applied to the cathode catalyst layer is not particularly limited as long as it has a catalytic action for the oxygen reduction reaction. The catalyst component applied to the anode catalyst layer is not particularly limited as long as it has a catalytic action on the oxidation reaction of hydrogen.

  The catalyst component is, for example, platinum, ruthenium, iridium, rhodium, palladium, osmium, tungsten, lead, iron, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum and other alloys, and alloys thereof. Selected.

  The polymer electrolyte of the electrode catalyst is not particularly limited as long as it is a member having at least high proton conductivity. For example, a fluorine-based electrolyte containing fluorine atoms in all or part of the polymer skeleton, or fluorine atoms in the polymer skeleton. A hydrocarbon-based electrolyte not included is applicable.

  The gas diffusion layer is formed of a member having sufficient gas diffusibility and conductivity, for example, carbon cloth woven with yarn made of carbon fiber, carbon paper, or carbon felt.

  The gaskets 132 and 137 are arranged so as to surround the outer periphery of the cathode electrode 130 and the anode electrode 135, and are fixed to the electrolyte membrane 120 via an adhesive layer (not shown).

  The gaskets 132 and 137 are made of a material (gas-impermeable material) that is impermeable to gas, particularly fuel gas or oxidant gas. Examples of the gas-impermeable material include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), and (polyvinylidene fluoride (PVDF)).

  Next, the first and second separators 140 and 160 will be described.

  The first separator 140 has an inner surface (second surface) 161 and an outer surface (first surface) 151 located on the opposite side of the inner surface 141.

  The inner side surface 141 is opposed to the cathode electrode 130 and has a protrusion 142 and a rib 143. The protrusion 142 extends along the outer periphery, and the membrane electrode assembly 110 (the gasket 132 fixed to the electrolyte membrane 120) is disposed on the inner side. A space between adjacent ribs forms a groove 144. The groove 144 constitutes an oxidant flow path for allowing the oxidant gas to flow, and is connected to an oxidant gas introduction port 74 and an oxidant gas discharge port 75 arranged in the end plate 70.

  The outer side surface 151 is opposed to the second separator 160 of another adjacent fuel cell unit cell 100 and has ribs 153 and 158. Spaces between adjacent ribs form grooves 154 and 159. The groove 154 constitutes a refrigerant flow path (first flow path) 169 for circulating the cooling medium (first cooling medium), and is connected to the refrigerant introduction port 76 and the refrigerant discharge port 78 arranged in the end plate 70. Has been. That is, the outer side surface 151 faces the coolant channel 168.

  The groove 159 is not in communication with the groove 154 and is used for arranging the second seal member 185.

  The second separator 160 has an inner surface (second surface) 161 and an outer surface (second surface) 171 located on the opposite side of the inner surface 161.

  The inner side surface 161 is opposed to the anode electrode 135 and has a protrusion 162 and a rib 163. The protrusion 162 corresponds to the protrusion 142 of the inner surface 141 of the first separator 140 and extends along the outer periphery. On the inner side, the membrane electrode assembly 110 (the gasket 137 fixed to the electrolyte membrane 120) is provided. To position.

  A space between adjacent ribs forms a groove 164. The groove 164 adjacent to the protrusion 162 and the other groove 164 (the groove 164 other than the groove 164 adjacent to the protrusion 162) are not in communication. The other groove portion 164 constitutes a fuel flow path for circulating fuel gas, and is connected to a fuel gas inlet 71 and a fuel gas outlet 72 arranged in the end plate 70.

  The outer side surface 171 is substantially flat and faces the outer side surface 151 of the first separator 140 of another adjacent fuel cell single cell 100. That is, the outer surface 171 faces the refrigerant flow path 168.

  The shape and arrangement of the ribs 143, 153, and 163 (groove portions 144, 154, and 164) are appropriately set in consideration of gas diffusibility, pressure loss, discharge of generated water, cooling performance, and the like.

  The height H of the protrusions 142 and 162 is appropriately set in consideration of the thickness of the membrane electrode assembly 110 in order to prevent the membrane electrode assembly 110 from being excessively crushed by the load for forming the stack. .

  The first and second separators 140 and 160 have appropriate conductivity, strength, and corrosion resistance, and are formed from a molding material having a powdery carbon material.

  The molding material is a powdery mixture having a carbon material (for example, 70 to 90 wt%) and a binder resin (for example, 10 to 30 wt%).

  The carbon material is, for example, natural graphite, artificial graphite, or expanded graphite.

  The binder resin is, for example, a thermosetting resin such as a phenol resin, a melamine resin, or a polyamide resin, or a thermoplastic resin such as polypropylene. Phenol resins are preferred because they are excellent in economic efficiency, workability, moldability, physical properties (acid resistance, heat resistance, fluid impermeability) and the like. The molding material is not limited to being directly used in the form of a powder, but can be applied in the form of a sheet-like preform or an assembly of billet-like preforms.

  Next, the first and second seal members 180, 182, and 185 will be described.

  The first seal member 180 has a tapered substantially trapezoidal cross-sectional shape, is disposed in the vicinity of the inner surface 141 of the outer periphery of the first separator 140 and the protrusion 142, and is relative to the gasket 132 fixed to the electrolyte membrane 120. is doing. The first seal member 182 has a tapered substantially trapezoidal cross-sectional shape, is disposed in the groove 164 adjacent to the inner surface 161 of the outer peripheral portion of the second separator 160 and the protrusion 162, and is fixed to the electrolyte membrane 120. 137. The refrigerant flow path 168 is positioned on the outer surfaces 151 and 171 located on the opposite side of the portion where the first seal members 180 and 182 are disposed. That is, the first seal members 180 and 182 are aligned with the refrigerant flow path 168.

  Therefore, when the cooling medium is circulated through the refrigerant flow path 168, the first seal members 180 and 182 that are heated by the heat generated during power generation are cooled to suppress thermal degradation, thereby improving the durability of the fuel cell. It is possible to make it.

  The first seal members 180 and 182 are made of an elastic seal material, and are fixed to the first and second separators 140 and 160 by an adhesive, for example. The elastic sealing material is particularly a material that can ensure the sealing performance between the first and second separators 140 and 160 and the membrane electrode assembly 110 and is impermeable to the fuel gas and the oxidant gas. Without being limited, for example, synthetic rubber such as butyl rubber.

  The second seal member 185 is disposed on the outer surface 151 of the outer peripheral portion of the first separator 140. As will be described later, the second seal member 185 is offset to the outside of the first seal members 180 and 182 disposed on the inner side surfaces 141 and 161 in order to improve productivity when manufacturing the fuel cell. To position. Therefore, the thickness is thinner than that in the case where the second seal member 185 and the first seal members 180 and 182 are aligned and arranged.

  The second seal member 185 is made of an adhesive seal material, and is positioned in the groove portion 159 disposed on the outer surface 151. As a result, the outer surface 151 of the first separator 140 and the outer surface 171 of the second separator 160 of another adjacent fuel cell single cell 100 are bonded to form a module body, thereby facilitating stack formation. .

  The adhesive sealing material is made of a thermosetting liquid adhesive. The thermosetting liquid adhesive is, for example, a synthetic resin adhesive such as a silicone adhesive or an epoxy resin adhesive, or a synthetic rubber adhesive such as a butyl rubber adhesive.

  The adhesive sealing material is not particularly limited as long as it is a material that can firmly bond the first separator 140 and the second separator 160 and is impermeable to the cooling medium. For example, polyolefin, polypropylene, Hot melt adhesives such as thermoplastic elastomers, acrylic adhesives, olefin adhesives such as polyesters and polyolefins can also be applied as appropriate.

  Next, the fuel cell cooling method according to Embodiment 1 will be described.

  The end plate 70 of the fuel cell 10 has a refrigerant inlet 76 and a refrigerant outlet 78 (see FIG. 1). When the cooling medium is supplied to the refrigerant introduction port 76, the cooling medium flows out from the refrigerant discharge port 78 via the refrigerant flow path 168 constituted by the groove portion 154 disposed in the first separator 140.

  The cooling medium flowing through the refrigerant flow path 168 cools the first and second separators 140 and 160, thereby keeping the temperature of the fuel cell that is heated by heat generated during power generation within a predetermined operating temperature range.

  On the other hand, the first seal members 180 and 182 are arranged on the inner side surfaces 141 and 161 located on the opposite side of the outer side surfaces 151 and 171 facing the refrigerant flow path 168 and are aligned with the refrigerant flow path 168. . Therefore, similarly, the cooling medium efficiently cools the first seal members 180 and 182 that are heated by heat generated during power generation. Thereby, since thermal degradation is suppressed, the durability of the fuel cell 10 is improved.

  Next, a hot press applied to the fuel cell manufacturing method according to Embodiment 1 will be described with reference to FIG.

  The hot press 190 hardens the second seal member 185 made of a thermosetting liquid adhesive, and the outer surface 151 of the first separator 140 and the outer surface of the second separator 160 of another adjacent fuel cell unit cell 100. 171 is bonded to form a module (forms a module body), and is used to facilitate stack formation, a molding die (upper die 191 and lower die 194), heating devices 197 and 198, and pressurization A mechanism 199 is included.

  The upper mold 191 is disposed so as to be able to approach and separate from the lower mold 194. The pressing surface 192 of the upper mold 191 has a groove 193 that contacts the protrusion 162 and the rib 163 disposed on the inner surface 161 of the second separator 160 and accommodates the first seal member 182 in a non-contact manner.

  The lower mold 194 is disposed in a fixed manner. The pressing surface 195 of the lower mold 194 has a groove 196 that contacts the protrusion 142 and the rib 143 of the inner surface 141 of the first separator 140 and accommodates the first seal member 180 in a non-contact manner.

  The heating devices 197 and 198 include cartridge heaters disposed inside the upper mold 191 and the lower mold 194, and are used to heat the upper mold 191 and the lower mold 194. The heated upper die 191 and lower die 194 raise the temperature of the second seal member 185 by the heat supplied by heat transfer and harden it.

  The pressurizing mechanism 199 has, for example, a hydraulic cylinder device, and is used to drive the upper mold 191 in cooperation with the lower mold 194 and harden the second seal member 185 under pressure.

  Next, a method for manufacturing the fuel cell according to Embodiment 1 will be described.

  First, the first separator 140 to which the first seal member 180 made of an elastic seal material is fixed is placed on the lower mold 194. At this time, the protrusion 142 and the rib 143 of the inner surface 141 of the first separator 140 abut the lower mold 194 and the pressing surface 195. On the other hand, the first seal member 180 is positioned in the groove portion 196 of the pressing surface 195 and thus is not in contact with the pressing surface 195.

  A second seal member 185 made of a thermosetting liquid adhesive is disposed (positioned) in the groove portion 159 disposed on the outer surface 151 of the first separator 140.

  The second separator 160 of another adjacent fuel cell single cell 100 to which the first seal member 182 is fixed is placed on the first separator 140. At this time, the outer surface 171 of the second separator 160 abuts the ribs 153 and 158 of the outer surface 151 of the first separator 140.

  The pressurizing mechanism 199 drives the upper mold 191 and lowers it toward the second separator 160. As a result, the pressing surface 192 of the upper mold 191 comes into contact with the protrusions 162 and the ribs 163 disposed on the inner surface 161 of the second separator 160 and exerts a pressing force on the first and second separators 140 and 160.

  On the other hand, the heating devices 197 and 198 heat the upper mold 191 and the lower mold 194, and the second seal member 185 is heated and cured by heat supplied by heat transfer. Thereby, the outer surface 151 of the first separator 140 and the outer surface 171 of the second separator 160 of another adjacent fuel cell unit cell 100 are bonded to form a module body.

  At this time, the second seal member 185 is disposed offset from the first seal members 180 and 182, compared to the case where the second seal member 185 and the first seal members 180 and 182 are aligned and disposed. Since the thickness is reduced, the influence of the first seal members 180 and 182 on the thermal conductivity between the second seal member 185 and the hot press is suppressed.

  Therefore, the curing time of the second seal member 185 is shortened and productivity is improved. Moreover, since this means shortening of the heating time of the 1st sealing members 180 and 182 which consist of elastic sealing materials, the thermal deterioration of the 1st sealing members 180 and 182 is also suppressed.

  Since stacking is achieved by repeating the arrangement of the membrane electrode assembly 110 between the module bodies, it is easy and has good productivity.

  Further, in the manufactured fuel cell, the outer surfaces 151, 171 located on the opposite side of the portion where the first seal members 180, 182 are disposed face the refrigerant flow path 168. Therefore, when the cooling medium is circulated through the refrigerant flow path 168, the first seal members 180 and 182 that are heated by the heat generated during power generation are cooled to suppress thermal degradation, thereby improving the durability of the fuel cell. It is possible to make it.

  As described above, in the first embodiment, a fuel cell capable of exhibiting good durability, a method for producing a fuel cell capable of exhibiting good durability, and good durability of the fuel cell are exhibited. It is possible to provide a cooling method.

  Next, a second embodiment will be described.

  FIG. 5 is a cross-sectional view for explaining the structure of the single fuel cell according to the second embodiment. In addition, about the member which has the function similar to Embodiment 1, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  The fuel cell according to Embodiment 2 is generally different from the fuel cell 10 according to Embodiment 1 with respect to the structure of a module body for facilitating stack formation.

  The fuel cell unit cell 200 includes a membrane electrode assembly, a first separator 240, a second separator 260, first seal members 280 and 282 made of a thermosetting liquid adhesive, and a second seal member 285 made of an elastic seal material. Have

  The inner surface 241 of the first separator 240 is opposed to the cathode electrode 230 and has a protrusion 242 and a rib 243. The protrusion 242 extends along the outer periphery, and a gasket 232 fixed to the electrolyte membrane 220 is disposed on the inner side.

  A space between adjacent ribs forms a groove 244. The groove part 244 adjacent to the protrusion part 242 is not in communication with the other groove part 244 and faces the electrolyte membrane 220 exposed in the gap between the cathode electrode 230 and the gasket 232, and the first seal Used to position member 280. The other groove portion 244 constitutes an oxidant flow path for circulating the oxidant gas, and is connected to an oxidant gas introduction port and an oxidant gas discharge port arranged in the end plate.

  The outer surface 251 of the first separator 240 is opposed to the second separator 260 of another adjacent fuel cell single cell 200 and has a rib 253. A space between adjacent ribs forms a groove 254. The groove 254 constitutes a refrigerant flow path 268 for circulating the cooling medium, and is connected to a refrigerant inlet and a refrigerant outlet arranged in the end plate.

  The inner side surface 261 of the second separator 260 is opposed to the anode electrode 235 and has a protrusion 262 and a rib 263. The protrusion 262 corresponds to the protrusion 242 of the inner surface 241 of the first separator 240, extends along the outer periphery, and a gasket 237 fixed to the electrolyte membrane 220 is disposed on the inner side.

  A space between adjacent ribs forms a groove 264. The groove part 264 adjacent to the protrusion part 262 does not communicate with the other groove part 264 and faces the electrolyte membrane 120 exposed in the gap between the anode electrode 235 and the gasket 237, and is a first seal member. Used to place 282. The other groove portion 264 constitutes a fuel flow path for circulating the fuel gas, and is connected to a fuel gas inlet and a fuel gas outlet arranged in the end plate.

  The outer surface 271 of the second separator 260 is opposed to the outer surface 251 of the first separator 240 of another adjacent fuel cell single cell 200 and has a rib 273. Spaces between adjacent ribs form grooves 274 and 279.

  The groove part 279 adjacent to the outer peripheral part is not in communication with the adjacent groove part 274 and is used for arranging the second seal member 285. As described above, the groove portion 274 is aligned with the groove portion 254 of the outer side surface 251 of the first separator 240 of another adjacent fuel cell unit cell 200, and is a refrigerant for circulating the cooling medium integrally. A flow path 268 is formed.

  The groove part 274 adjacent to the groove part 279 is aligned with the groove part 264 of the inner surface 261 used for disposing the first seal member 282. Further, the groove 274 adjacent to the groove 279 is adjacent to the protrusion 242 of the inner surface 241 of the first separator 240 of another adjacent fuel cell single cell 200 used for disposing the first seal member 280. The groove portion 244 is aligned.

  That is, the first seal members 280 and 282 are aligned with the refrigerant flow path 268 of the second separator 260 and the refrigerant flow path 268 of the first separator 240 of the adjacent another fuel cell single cell 200, In addition, the first seal members 280 and 282 are disposed offset from the second seal member 285.

  Therefore, when the cooling medium is circulated through the refrigerant flow path 268, the first seal members 280 and 282 that are heated by heat generated during power generation are cooled to suppress thermal deterioration, thereby improving the durability of the fuel cell. The thickness of the first seal members 280, 282 and the second seal member 285 is reduced compared to the case where the first seal members 280, 282 and the second seal member 285 are aligned.

  Furthermore, the first seal members 280 and 282 are formed by bonding the electrolyte membrane 220 (membrane electrode assembly) and the inner surfaces 241 and 261 of the first separator 240 and the second separator 260 to form a module body. Therefore, compared with the module body of the first embodiment, the number of parts for forming a stack is reduced, and productivity can be further improved.

  FIG. 6 is a cross-sectional view for explaining a method of manufacturing the fuel cell of FIG.

  A hot press 290 applied to the method for manufacturing a fuel cell according to the second embodiment is generally different from the first embodiment with respect to the configurations of the upper mold 291 and the lower mold 294.

  The upper die 291 has a pressing surface 292 that is disposed so as to be able to approach and separate from the lower die 294 and abuts against the outer surface 251 (rib 253) of the first separator 240. The lower mold 294 is arranged in a fixed manner and has a pressing surface 295 that comes into contact with the outer surface 271 (rib 273) of the second separator 260. Further, the pressing surface 295 has a groove portion 296 for receiving the second seal member 285 in a non-contact manner.

  Next, a method for manufacturing the fuel cell according to Embodiment 2 will be described.

  First, the second separator 260 in which the second seal member 285 made of an elastic seal material is fixed to the groove 279 adjacent to the outer peripheral portion of the outer surface 271 is placed on the lower mold 294. At this time, the second seal member 285 is positioned in the groove portion 296 of the pressing surface 295. A first seal member 282 made of a thermosetting liquid adhesive is disposed in the groove 264 adjacent to the protrusion 262 on the inner surface 261 of the second separator 260.

  The membrane electrode assembly is placed on the second separator 240. At this time, the electrolyte membrane 220 exposed in the gap between the anode electrode 235 and the gasket 237 is positioned so as to face the first seal member 282.

  A first separator 240 in which a first seal member 280 made of a thermosetting liquid adhesive is disposed in a groove 244 adjacent to the protrusion 242 of the inner surface 241 is placed on the membrane electrode assembly. At this time, the first seal member 280 is positioned so as to face the electrolyte membrane 220 exposed in the gap between the cathode electrode 230 and the gasket 232.

  The pressurizing mechanism 299 drives the upper mold 291 and lowers it toward the second separator 260. The pressing surface 292 of the upper mold 291 is in contact with the outer surface 251 (rib 253) of the first separator 240 and applies a pressing force to the first and second separators 240 and 260.

  On the other hand, the heating devices 297 and 298 heat the upper mold 291 and the lower mold 294, and heat and cure the first seal members 280 and 282 by heat supplied by heat transfer. Thereby, the electrolyte membrane 220 (membrane electrode assembly) and the inner side surfaces 241 and 261 of the first separator 240 and the second separator 260 are bonded together.

  At this time, the first seal members 280 and 282 are disposed offset from the second seal member 285, compared to the case where the first seal members 280 and 282 and the second seal member 285 are aligned and disposed. Since the thickness is reduced, the influence of the second seal member 285 on the thermal conductivity between the first seal members 280 and 282 and the hot press is suppressed.

  Accordingly, the curing time of the first seal members 280 and 282 is shortened, and the productivity is improved. In addition, this means shortening the heating time of the second seal member 285 made of an elastic seal material, so that thermal deterioration of the second seal member 285 is also suppressed.

  In addition, since stacking is achieved by simply stacking the module bodies, it is very easy and the productivity can be further improved.

  In the manufactured fuel cell, the outer surfaces 251 and 271 located on the opposite side of the portion where the first seal members 280 and 282 are disposed face the refrigerant flow path 268. Therefore, when the cooling medium is circulated through the refrigerant flow path 268, the first seal members 280 and 282 that are heated by heat generated during power generation are cooled to suppress thermal deterioration, thereby improving the durability of the fuel cell. It is possible to make it.

  Note that the fuel cell cooling method is substantially the same as that of the first embodiment, and thus the description thereof is omitted.

  As described above, the second embodiment can further improve the productivity when forming a stack as compared with the first embodiment.

  Next, a third embodiment will be described.

  7 is a perspective view for explaining the cooling method of the fuel cell according to Embodiment 3, FIG. 8 is a cross-sectional view for explaining the structure of the single fuel cell of FIG. 7, and FIG. It is a conceptual diagram for demonstrating control of the 1st cooling medium of the fuel cell of. In addition, about the member which has the function similar to Embodiment 2, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  The third embodiment relates to a fuel cell cooling structure and a cooling method, and is generally different from the second embodiment.

  The fuel cell 310 according to Embodiment 3 has first and second refrigerant introduction ports 376 and 377, and first and second refrigerant discharge ports 378 and 379, and the fuel cell single cell 400 includes the first and second refrigerant cells 400. Refrigerant flow paths (first and second flow paths) 468 and 469 are provided. Reference numerals 371, 372, 374, and 375 indicate a fuel gas inlet, a fuel gas outlet, an oxidant gas inlet, and an oxidant gas outlet, respectively.

  The first refrigerant flow path 468 is configured by a groove portion 474 adjacent to the groove portion 479 used for disposing the second seal member 485 on the outer surface 471 of the second separator 460. 1 is connected to the refrigerant outlet 378.

  The second refrigerant channel 469 is configured by other groove portions 474 (groove portions 474 other than the groove portion 474 adjacent to the groove portion 479), and is connected to the second refrigerant introduction port 377 and the second refrigerant discharge port 379.

  The groove part 474 adjacent to the groove part 479 and the other groove part 474 do not communicate with each other, and the first cooling medium flowing through the first refrigerant flow path 468 and the second cooling medium flowing through the second refrigerant flow path 469 are: Independently temperature controlled. That is, the fuel cell 310 has two independent refrigerant distribution systems.

  A groove 474 adjacent to the groove 479 is aligned with the first seal members 480 and 482. Therefore, it is possible to cool the first seal members 480 and 482 by introducing the first cooling medium into the first refrigerant flow path 468. On the other hand, by introducing the second cooling medium into the second refrigerant channel 469, it is possible to cool the fuel cell 310 that is heated by heat generated during power generation.

  At this time, since the temperature of the first cooling medium and the second cooling medium is independently controlled, the temperature of the first cooling medium is set to an optimum value for cooling the first seal members 480 and 482. By setting the temperature of the second cooling medium to an optimum value for cooling the fuel cell 310, it is possible to easily achieve the temperature of the fuel cell 310 within a predetermined operating temperature range.

  The presence of the two-system refrigerant flow system controlled independently is particularly preferable when the linear thermal expansion coefficient of the first seal members 480 and 482 is larger than the linear thermal expansion coefficient of the electrolyte membrane 420.

  For example, as shown in FIG. 9, the electrolyte membrane 420 is fixed by first seal members 480 and 482, and the temperature of the fuel cell 310 reaches 100 ° C. or more due to heat generated during power generation. Therefore, if the difference ΔE in elongation between the electrolyte membrane 420 and the first seal members 480 and 482 becomes excessively large, the adhesion interface between the electrolyte membrane 420 and the first seal members 480 and 482 may be broken, May cause damage.

  However, in the third embodiment, the first cooling medium is introduced into the first refrigerant channel 468 and the first seal members 480 and 482 are cooled, so that the electrolyte membrane 420 and the first seal members 480 and 482 It is possible to reduce the difference ΔE in the amount of elongation and reduce the stress on the electrolyte membrane 420.

  The temperature of the first cooling medium is appropriately controlled according to the type of the first seal members 480 and 482. For example, when the first seal members 480 and 482 are made of a silicone adhesive, an epoxy resin adhesive, or a butyl rubber adhesive, the temperature of the first cooling medium is 10 ° C., 15 ° C., or 20 ° C., respectively. It is.

  As described above, in the third embodiment, the temperature control of the first seal members 480 and 482 is easier than in the second embodiment, and the stress on the electrolyte membrane 420 can be reduced. Note that the two independent refrigerant distribution systems according to the third embodiment can be applied to the first embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, the first and second separators can be formed of a metal material having appropriate conductivity, strength, and corrosion resistance. The metal material is, for example, a stainless steel plate. Stainless steel plates are preferred because they are easy to perform complex machining and have good electrical conductivity. The stainless steel plate can be coated with a corrosion-resistant coating as necessary. An aluminum plate or a clad material can also be applied.

1 is a perspective view for explaining a fuel cell according to Embodiment 1. FIG. It is an exploded view for demonstrating the structure of the fuel cell single cell of FIG. It is sectional drawing for demonstrating the structure of the fuel cell single cell of FIG. It is sectional drawing for demonstrating the manufacturing method of the fuel cell of FIG. 5 is a cross-sectional view for explaining the structure of a single fuel cell according to Embodiment 2. FIG. It is sectional drawing for demonstrating the manufacturing method of the fuel cell of FIG. FIG. 6 is a perspective view for explaining a cooling method for a fuel cell according to a third embodiment. It is sectional drawing for demonstrating the structure of the fuel cell single cell of FIG. It is a conceptual diagram for demonstrating control of the 1st cooling medium of the fuel cell of FIG.

Explanation of symbols

10. Fuel cell,
20. Stack part,
30, 40 ... current collector,
35, 45 ... Output terminal,
50, 60 ... insulation board,
70,80 ... End plate,
71. Fuel gas inlet,
72 .. Fuel gas outlet,
74 .. Oxidant gas inlet,
75 .. Oxidant gas outlet,
76 .. Refrigerant inlet,
78 .. Refrigerant outlet
90..Tie rod,
100 ... Fuel cell single cell,
110 .. Membrane electrode assembly,
120..Electrolyte membrane,
130 .. Cathode electrode,
132 .. Gasket,
135 .. Anode electrode,
137..Gasket,
140 .. First separator,
141..Inside surface,
142 .. Projection,
143 ・ ・ Rib,
144 .. groove part,
151 .. Outer surface,
153,158 ・ ・ Rib,
154,159 ..groove part,
160 .. second separator,
161..Inside surface,
162 .. Protrusions,
163 ・ ・ Rib,
164 .. groove part,
168 .. Refrigerant flow path,
171 .. Outer surface,
180, 182 .. first seal member,
185 .. Second seal member,
190 ・ ・ Hot press,
191 ... Upper mold,
192..Pressing surface,
193 ...
194 ... Lower mold,
195 ... Pressing surface,
196 ・ ・ Groove,
197, 198 · · heating device,
199 ... Pressure mechanism,
200 ... Fuel cell single cell,
220..Electrolyte membrane,
230 .. Cathode electrode,
232 ... Gasket,
235 .. Anode electrode,
237 .. Gasket,
240 .. first separator,
241 ... Inside surface,
242 .. Protrusions,
243 ・ ・ Rib,
244 .. Groove,
251 .. Outer surface,
253 ... Rib,
254 ・ ・ Groove,
260 .. second separator,
261 ... inner surface,
262 .. Projection,
263 ... ribs,
264 .. Groove part,
268 .. Refrigerant flow path,
271 .. Outer surface,
273 ... ribs
274, 279 ...
280, 282 .. First seal member,
285 .. Second seal member,
290 ... Hot press,
291 ... Upper mold,
292..Pressing surface,
294 ... Lower mold,
295 ... Pressing surface,
296 .. groove part,
297,298 ... Heating device,
299 ... Pressure mechanism,
310 .. Fuel cell,
371 ... Fuel gas inlet,
372 .. Fuel gas outlet,
374 .. Oxidant gas inlet,
375 .. Oxidant gas outlet,
376 .. First refrigerant inlet,
377 .. Second refrigerant inlet,
378 .. First refrigerant discharge port,
379 .. Second refrigerant outlet,
400 ... Fuel cell single cell,
420 .. Electrolyte membrane,
460 .. second separator,
468 .. First refrigerant flow path,
469 .. second refrigerant flow path,
471 .. Outer surface,
474, 479 .. Groove,
480, 482 .. first seal member,
485 .. second seal member,
H, height,
ΔE ... difference.

Claims (27)

Membrane electrode assembly,
A separator having a groove,
A first flow path for circulating the first cooling medium; and
A first seal member disposed on the outer periphery of the separator;
The first seal member is disposed on a second surface of the separator that is located on the opposite side of the first surface facing the first flow path, and is aligned with the first flow path. A fuel cell.   The fuel cell according to claim 1, wherein the first flow path is formed by a groove portion of the separator.   The second seal member disposed on the first surface of the outer peripheral portion of the separator, wherein the second seal member is offset and positioned outside the first seal member. The fuel cell according to claim 2.   The fuel cell according to claim 3, wherein the first seal member is made of an elastic seal material.   5. The fuel cell according to claim 4, wherein the second seal member is made of an adhesive seal material, and bonds the first surface of the separator and the first surface of the adjacent separator.   The fuel cell according to claim 5, wherein the adhesive sealing material is made of a thermosetting liquid adhesive. The membrane electrode assembly has an electrolyte membrane disposed on the second surface of the separator and exposed,
4. The fuel cell according to claim 3, wherein the first seal member is made of an adhesive seal material, and adheres the exposed electrolyte membrane and the second surface of the separator. 5.   The fuel cell according to claim 7, wherein the adhesive sealing material is made of a thermosetting liquid adhesive.   9. The fuel cell according to claim 7, wherein the second seal member is made of an elastic seal material. Having a second flow path for circulating the second cooling medium;
The first flow path is applied to cool the first seal member;
The fuel cell according to any one of claims 1 to 9, wherein the second flow path is applied to keep the temperature of the fuel cell within a predetermined operating temperature range. A method of manufacturing a fuel cell having a membrane electrode assembly, a separator having a groove, a first flow path for circulating a first cooling medium, a first seal member, and a second seal member,
The first seal member is disposed in alignment with the first flow path on a second surface located on the opposite side of the first surface facing the first flow path in the outer peripheral portion of the separator,
The second seal member is made of a thermosetting liquid adhesive, is disposed on the first surface of the outer periphery of the separator, and is offset from the outside of the first seal member,
Bringing the first surface of the separator into contact with the first surface of the adjacent separator;
The method of manufacturing a fuel cell, wherein the second seal member is cured by hot pressing to bond the first surface of the separator and the first surface of the adjacent separator.   The method of manufacturing a fuel cell according to claim 11, wherein the first flow path is formed by a groove portion of the separator.   The method of manufacturing a fuel cell according to claim 11, wherein the first seal member is made of an elastic seal material. The fuel cell has a second flow path for circulating the second cooling medium,
The first flow path is applied to cool the first seal member;
The method for manufacturing a fuel cell according to any one of claims 11 to 13, wherein the second flow path is applied to keep the temperature of the fuel cell within a predetermined operating temperature range. A method of manufacturing a fuel cell having a membrane electrode assembly, a separator having a groove, a first flow path for circulating a first cooling medium, a first seal member, and a second seal member,
The first seal member is made of a thermosetting liquid adhesive, and on the second surface located on the opposite side of the first surface facing the first flow channel in the outer periphery of the separator, Aligned and placed
The second seal member is disposed on the first surface of the outer peripheral portion of the separator, and is offset and positioned outside the first seal member;
The membrane electrode assembly has an electrolyte membrane disposed on the second surface of the separator and exposed,
A method of manufacturing a fuel cell, comprising: curing the first seal member by hot pressing to bond the second surface of the separator and the electrolyte membrane from which the membrane electrode assembly is exposed. .   The fuel cell manufacturing method according to claim 15, wherein the first flow path is formed by a groove portion of the separator.   The method of manufacturing a fuel cell according to claim 15 or 16, wherein the second seal member is made of an elastic seal material. The fuel cell has a second flow path for circulating the second cooling medium,
The first flow path is applied to cool the first seal member;
The method for producing a fuel cell according to any one of claims 15 to 17, wherein the second flow path is applied to keep the temperature of the fuel cell within a predetermined operating temperature range. A fuel cell cooling method comprising:
The fuel cell
Membrane electrode assembly,
A separator having a groove,
A first flow path for circulating the first cooling medium; and
A first seal member disposed on the outer periphery of the separator;
The first seal member is disposed on a second surface of the separator located on the opposite side of the first surface facing the first flow path, and is aligned with the first flow path;
A method for cooling a fuel cell, comprising: circulating a first cooling medium in the first flow path to cool the first seal member that is heated by heat generated during power generation.   The fuel cell cooling method according to claim 19, wherein the first flow path is formed by a groove of the separator.   The second seal member disposed on the first surface of the outer peripheral portion of the separator, wherein the second seal member is offset and positioned outside the first seal member. The method for cooling a fuel cell according to claim 20.   The method of claim 21, wherein the first seal member is made of an elastic seal material.   23. The fuel cell cooling according to claim 22, wherein the second seal member is made of an adhesive seal material and adheres the first surface of the separator and the first surface of the adjacent separator. Method. The membrane electrode assembly has an electrolyte membrane disposed on the second surface of the separator and exposed,
The cooling of the fuel cell according to claim 21, wherein the first seal member is made of an adhesive seal material, and adheres the exposed electrolyte membrane and the second surface of the separator. Method.   The method of claim 24, wherein the second seal member is made of an elastic seal material. The first seal member has a linear thermal expansion coefficient larger than that of the electrolyte membrane,
26. The temperature of the first cooling medium is controlled so as to reduce a difference between an extension amount of the first seal member and an extension amount of the electrolyte membrane. Fuel cell cooling method. The fuel cell has a second flow path for circulating the second cooling medium,
Flowing the second cooling medium through the second flow path to cool the fuel cell that is heated by heat generated during power generation, and keeping the temperature of the fuel cell within a predetermined operating temperature range. The method for cooling a fuel cell according to any one of claims 19 to 26, wherein:

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