JP2010277742A - Battery cell, and fuel battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve effectiveness of peeling prevention of a peripheral edge of porus bodies in integrating a cell structuring member including an MEA (membrane-electrode assembly) and the porus bodies on both sides at peripheral edges with an elastic seal member. <P>SOLUTION: In integrating the cell structuring member 30 and a first porus body 40 of the battery cell 20 at the peripheral edges with the elastic seal member 60, a step part 42 of the first porus body 40 is positioned inside the elastic seal member 60. Therefore, the elastic seal member 60 includes an upper surface part 61 of a step part formed on an upper surface side of the step part 42 of the first porus body 40, and a lower surface part 62 of the step part formed between the step part 42 and a protection film 37 around the cell structuring member 30 in forming the elastic seal member 60. Thereby, the elastic seal member 60 vertically sandwiches the step part 42 as a peripheral edge part of the first porus body 40 in a thickness direction of the porus body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a battery cell as a power generation unit of a fuel cell and a fuel cell provided with the cells stacked.

  The fuel cell generates electricity by advancing an electrochemical reaction between a fuel, for example hydrogen, in the fuel gas supplied to the anode and oxygen in the oxygen-containing gas supplied to the cathode. Since this electrochemical reaction proceeds in a membrane-electrode assembly (MEA) in which a catalyst electrode is joined to an electrolyte membrane, in order to secure a generated electromotive force, a cell constituent member including MEA and a separator A fuel cell having a so-called stack structure is known in which are stacked alternately and fastened in the stacking direction.

  By the way, in order to make the gas supply to the electrode surface uniform, the cell constituent member is usually provided with a gas diffusion layer on both sides of the MEA and is sandwiched by a porous body having continuous pores made of a metal mesh or the like. The battery cell is configured. On the other hand, in each of the stacked battery cells, in order to ensure the air tightness and liquid tightness of the anode electrode and the cathode electrode on both sides of the MEA, the cell constituent member including the MEA and the porous body on the both sides are arranged at the periphery. A technique for securing a seal while being integrated by an elastic seal member is known (for example, Patent Document 1).

JP 2008-123883 A

  According to the technique proposed in the above-mentioned patent document, the peripheral edge of the porous body and the elastic seal member are impregnated with the material for forming the elastic seal member into the continuous pores at the peripheral edge of the porous body joined to the elastic seal member. A so-called anchor effect is expressed between the two and the peeling at the periphery of the porous body is prevented. By the way, the integration by the elastic seal member is carried out through the setting of the cell constituent member and the porous body into the mold, the injection of the material for forming the elastic seal member, and the demolding. If the adhesion of the material is large, the peripheral edge of the porous material may be peeled off during demolding. For this reason, work for reducing the adhesion of the porous body to the mold surface of the mold and reworking when peeling occurs are required, and the complexity has been pointed out.

  In light of the above-described problems, the present invention enhances the effectiveness of preventing the peripheral edge of the porous body from being integrated when the cell constituent member including the MEA and the porous body on both sides thereof are integrated with the elastic seal member at the peripheral edge. That is the purpose.

  In order to achieve at least a part of the above object, the present invention adopts the following configuration.

[Application: Battery cell]
A battery cell as a power generation unit of a fuel cell,
A cell constituent member including a membrane electrode assembly in which a catalyst electrode is joined to an electrolyte membrane;
A porous body forming a gas diffusion supply path with continuous pores;
An elastic seal member that surrounds and integrates the cell constituent member and the porous body superposed on both sides thereof over the periphery thereof;
The gist of the porous body is provided with a peripheral portion that is thinner than a portion inside the peripheral portion of the porous body at a peripheral portion of the porous body, and the peripheral portion is positioned inside the elastic seal member. .

  In the battery cell having the above configuration, at the periphery of the porous body integrated by the elastic seal member, the porous body has a thinner peripheral part than the inner part of the peripheral part of the porous body, and the peripheral part is the elastic seal. Located inside the member. For this reason, the elastic seal member sandwiches the peripheral portion of the porous body between the upper and lower sides in the thickness direction of the porous body. Therefore, even if a force that causes the peripheral edge to peel off acts on the porous body, for example, even if the adhesion force between the mold surface of the mold and the porous body at the time of demolding acts on the porous body, At the periphery of the porous body, the elastic seal member functions to hold down the peripheral portion of the porous body against the above force from the outer surface side. Not only the adhesion force at the time of demolding, the same applies even if other forces act so as to peel off the periphery of the porous body. As a result, according to the battery cell having the above configuration, peeling of the periphery of the porous body can be prevented with high effectiveness.

  The battery cell described above can be configured as follows. For example, the porous body is provided with a sealing portion that fills the continuous pores on the peripheral side of the porous body so as to avoid impregnating the porous body with the material for forming the elastic seal member In addition, the peripheral portion is positioned closer to the peripheral side than the eye stop portion. In this way, the elastic sealing member can be used to prevent the peripheral edge of the porous body from being peeled by pressing the peripheral portion of the porous body, and the porous sealing member can be prevented from being impregnated with the elastic sealing member inside the sealing portion. The gas diffusion supply in the body can be ensured.

  Moreover, the said peripheral part can be made into the thing which has the level | step-difference part made into the step shape by crushing the said porous body periphery. By so doing, the strength of the stepped portion is increased by crushing, so the effect of suppressing the peripheral portion (stepped portion) of the porous body by the elastic seal member is increased, and the effectiveness of preventing the peripheral edge of the porous body from peeling off is further increased.

  In this case, in the peripheral part on the peripheral side of the sealing part, the continuous pores have an impregnation part impregnated with the material for forming the elastic seal member between the step part and the sealing part. It can also be. In this way, the effect of preventing the peripheral edge of the porous body from being peeled by the pressing effect of the peripheral part (step part) of the porous body by the elastic seal member and the anchor effect by impregnating the material for forming the elastic seal member at the impregnated part. The sex can be increased.

  Moreover, the said peripheral part can have a bottomed part constricted in the said porous body peripheral part. In this way, the elastic sealing member exists so as to fill the bottomed portion of the porous body and then presses down the bottomed portion to prevent the peripheral edge of the porous body from peeling off.

  In this case, the peripheral part has a peripheral part extending from the bottomed part to the peripheral part of the porous body, and the continuous pores of the peripheral part are impregnated with a material for forming the elastic seal member. be able to. In this way, the porous body has a pressing effect on the bottomed portion of the porous body by the elastic seal member, and an anchor effect by impregnating the material for forming the elastic seal member at the peripheral portion on the peripheral side of the bottomed portion. The effectiveness of preventing peeling of the peripheral edge can be further enhanced. Moreover, since the elastic seal member that fills the bottomed portion is connected to the forming material impregnated in the peripheral portion with the forming material of the portion, the pressing effect of the elastic seal member is further enhanced, and the peripheral edge of the porous body is prevented from peeling off. Effectiveness is further enhanced.

  The battery cell further includes a separator bonded to one side of the porous body overlapping the cell constituent member, and the porous body on the separator side and the other porous body. At least one of the solid bodies can be a porous body having the peripheral portion. If it carries out like this, in a battery cell equipped with a separator joined, the above-mentioned effect can be produced.

  The present invention can be applied not only as a battery cell but also as a fuel cell provided with a plurality of stacked battery cells.

It is explanatory drawing which shows schematic structure of the fuel cell 10 as an Example of this invention. It is explanatory drawing which shows the battery cell 20 of the structural unit of this fuel cell 10 by side view. 4 is a flowchart showing a manufacturing procedure of the fuel cell 10. FIG. 3 is an explanatory view showing a main part of a battery cell 20 in cross-section. FIG. 4 is an explanatory diagram showing a state of producing a first porous body 40 that constitutes a battery cell 20. It is a flowchart which shows the manufacture procedure of the battery cell 20 of an Example. It is explanatory drawing for writing together and explaining the shaping | molding die using the mode of the shaping | molding of the battery cell. FIG. 6 is an explanatory diagram for explaining an advantage of the battery cell 20. FIG. 6 is an explanatory view showing the first porous body 40A of the second embodiment together with its production and integration with the elastic seal member 60, corresponding to FIG. FIG. 4 is an explanatory diagram corresponding to FIG. 4 and an enlarged view showing a part of a battery cell 20A of a third embodiment as viewed in cross section. FIG. 10 is an equivalent view of FIG. 10, and is an explanatory view showing a part of the battery cell 20 </ b> B of the fourth embodiment in an enlarged manner while viewing a cross-sectional view.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell 10 as an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a side view of a battery cell 20 of a unit of the fuel cell 10, and FIG. It is a flowchart which shows the manufacturing procedure of.

  As shown in FIGS. 1 and 2, the fuel cell 10 has a structure in which a plurality of battery cells 20 are stacked (so-called stack structure). In manufacturing the fuel cell 10, as shown in FIG. 3, first, a predetermined number of battery cells 20 are stacked (step S102), and the stacked battery cells 20 are loaded with a predetermined fastening force in the stacking direction. Fasten (step S104). Since the battery cell 20 is a unit of power generation in the fuel cell 10, the power generation capability of the fuel cell 10 is determined by the number of stacks. Therefore, in step S100, the number of battery cells 20 determined according to the power generation capacity required for the fuel cell 10 are stacked, and in step S104, the cells are fastened with a fastening force determined from a request for maintaining a seal between the cells.

  As shown in FIG. 1, each battery cell 20 of the fuel cell 10 has an oxidizing gas supply manifold 11 to which an oxidizing gas (oxygen-containing gas) is supplied, an oxidizing gas discharge manifold 12 that discharges the oxidizing gas, and a fuel. A fuel gas supply manifold 13 that supplies gas, a fuel gas discharge manifold 14 that discharges fuel gas, a cooling medium supply manifold 15 that supplies cooling medium, and a cooling medium discharge manifold 16 that discharges cooling medium are provided. It has been. Note that air is generally used as the oxidizing gas, and hydrogen is generally used as the fuel gas. Further, both the oxidizing gas and the fuel gas are also called reaction gases. As the cooling medium, water, antifreeze water such as ethylene glycol, air, or the like can be used.

  Next, a characteristic configuration of the battery cell 20 will be described. FIG. 4 is an explanatory view showing the main part of the battery cell 20 in cross-section, and FIG. 5 is an explanatory view showing a state of manufacturing the first porous body 40 constituting the battery cell 20. As shown in FIG. 4, the battery cell 20 includes a cell constituent member 30, first porous bodies 40 and second porous bodies 50 on both sides thereof, an elastic seal member 60, and a separator 70. The cell constituent member 30 includes a membrane electrode assembly (hereinafter referred to as MEA) 32 in which catalyst electrodes are joined to both surfaces of an electrolyte membrane, and an anode side gas diffusion layer 34 and a cathode side gas diffusion layer on both sides thereof. 36 are integrated with a technique such as hot pressing. The MEA 32 is made of, for example, an ion exchange membrane formed of a fluorine-based resin material or a hydrocarbon-based resin material and having good ionic conductivity in a wet state. The MEA 32 is made of platinum or platinum and other metals on both surfaces. A catalyst electrode containing an alloy as a catalyst is formed by a technique such as application of catalyst ink. Both the anode and cathode gas diffusion layers are formed of, for example, carbon cloth woven with yarns made of carbon fibers, carbon paper or carbon felt, and the supplied oxidizing gas / fuel gas is diffused and supplied to the MEA 32. In the present embodiment, the peripheral upper and lower surfaces of the MEA 32 are covered with the protective film 37, thereby protecting the MEA 32 from the fluff on the surfaces of the two gas diffusion layers. The protective film 37 is formed on the upper and lower surfaces of the peripheral edge of the MEA 32 using a material having heat resistance and acid resistance, for example, synthetic resin such as polyethylene terephthalate and polybutylene terephthalate, and rubber such as chlorobrene rubber.

  Both porous bodies of the first porous body 40 and the second porous body 50 are formed of a porous material having gas diffusibility and conductivity such as a metal porous body. This porous body has a higher porosity than the above-mentioned anode side gas diffusion layer 34 and cathode side gas diffusion layer 36 and has a lower gas flow resistance than both gas diffusion layers. The pores are used as gas diffusion supply paths. The first porous body 40 is provided with a sealing portion 41 and a stepped portion 42 side by side on the periphery of the porous body on the right end side in FIG. 4, and the stepped portion 42 is formed with a step 43 from the surface of the porous body. . As shown in FIG. 5, in producing the first porous body 40, first, the first porous body 40 having a plate shape is prepared (FIG. 5A), and then the first porous body on the peripheral side is prepared. The press body P is pressed against the material body 40 to crush the periphery of the porous body, thereby forming the step portion 42 with the step 43 (FIG. 5B). Since the stepped portion 42 is in a state where the continuous pores are almost crushed by being crushed by the press body P, the strength is higher than that of the central portion of the first porous body 40, that is, the gas diffusion supply portion.

  Subsequent to the formation of the stepped portion 42, the porous body portion that follows the portion is set as the formation portion of the sealing portion 41, and the resin is sprayed from the resin ejection nozzle S facing the portion (FIG. 5C). The sprayed resin enters the continuous pores of the porous body at the location facing the nozzle, fills the continuous pores after drying, and forms the sealing portion 41. For this reason, the sealing part 41 avoids impregnation of the first porous body 40 with the material for forming the elastic seal member 60 in the manufacturing process of the battery cell 20 described later. As the resin for forming the sealing portion 41, a low-viscosity epoxy resin, a silicone resin, a phenol resin, a urethane resin, or the like that can enter the porous pores is preferable. Instead of resin, rubber that is dry and hardened with low viscosity, for example, fluorine rubber, silicone rubber, acrylic rubber, or the like can be used.

  The above-described sealing portion 41 and the stepped portion 42 subsequent thereto are located on the end side of the first porous body 40 in FIG. Incidentally, since the battery cell 20 has a rectangular shape as shown in FIG. 1, the sealing portion 41 and the stepped portion 42 exist so as to surround the central side portion (gas diffusion supply portion) of the first porous body 40. However, the stepped portion 42 is thinner by the stepped portion 43 than the gas diffusion supply portion at the periphery of the first porous body 40. Then, after the formation of the elastic seal member 60 described later, the sealing portion 41 extends toward the elastic seal member 60 in accordance with the peripheral edge of the anode-side gas diffusion layer 34, and the step portion 42 is formed on the elastic seal member 60. It will be located inside. And the level | step-difference site | part 42 is located in the porous body peripheral side rather than the sealing site | part 41. FIG.

  The second porous body 50 is surrounded by the elastic seal member 60 in the battery cell manufacturing process in a state of being joined to the separator 70 described later, and does not contact the elastic seal member 60 on the surface on the separator 70 side. For this reason, in the second porous body 50, it is only necessary to prevent the elastic seal member material from entering the central side portion (gas diffusion supply portion). A portion 51 is provided. Even in the sealing portion 51, it exists so as to surround the central side portion (gas diffusion supply portion) of the second porous body 50, and the elastic sealing member 60 side is aligned with the peripheral edge of the cathode side gas diffusion layer 36. It extends to.

  The elastic sealing member 60 has a cell constituent member 30 having an MEA 32, and a first porous body 40 and a second porous body 50 on both sides of the cell structural member 30 in a state where they overlap each other as shown in FIG. Surround and integrate. Since the peripheral edges of these members are integrated over the peripheral edge, leakage of the reaction gas from the cathode side to the anode side of the MEA 32 or from the anode side to the cathode side is suppressed. In addition to such integration, the elastic seal member 60 also forms a manifold such as the oxidizing gas discharge manifold 12 shown in FIG. 1 and has gas impermeability, elasticity, and heat resistance in the operating temperature range of the fuel cell. It is made of a material, for example, an elastic material such as rubber or elastomer. Specifically, silicone rubber, butyl rubber, acrylic rubber, natural rubber, fluorine rubber, ethylene / propylene rubber, styrene elastomer, fluorine elastomer and the like can be used. The elastic seal member 60 is formed on the surface of the separator 70 when the battery cell 20 is molded as described later.

  The elastic seal member 60 formed of the above material includes a rib protrusion 64 on the side opposite to the separator 70 and a recess 65 on the protrusion base. The rib protrusion 64 and the recess 65 are formed for each manifold so as to surround a manifold such as the oxidizing gas discharge manifold 12 shown in FIG. When the fuel cell 10 is formed through the stacking / fastening of the battery cell 20, the rib protrusion 64 of a certain battery cell 20 receives the fastening force in the stacking direction, and is crushed by being joined to the separator 70 of the adjacent battery cell 20, The surrounding manifold is hermetically sealed. In this case, the crushing margin of the rib protrusion 64 is absorbed by the recess 65.

  The separator 70 is configured by sandwiching an intermediate plate 73 between a first plate 71 and a second plate 72 made of a corrosion-resistant metal steel plate, for example, a stainless steel plate, and in these plates, the cooling channel and fuel gas in the cell A flow path and a participating gas flow path are formed. In FIG. 4, since the separator 70 is located on the cathode side gas diffusion layer 36 side and is included in the battery cell 20, the oxidizing gas is supplied to the second porous body 50 of the battery cell 20 including the separator 70. And a fuel gas channel for supplying fuel gas to the first porous body 40 of the battery cell 20 stacked on the lower side in FIG. 4 is formed.

  Next, the manufacturing method of the battery cell 20 provided with the said structure is demonstrated. FIG. 6 is a flowchart showing a manufacturing procedure of the battery cell 20 of the embodiment. FIG. 7 is an explanatory diagram for explaining the mold using the state of the molding of the battery cell 20 together.

  When manufacturing the battery cell 20, as shown in FIG. 6, first, a molding die for integral molding is prepared (step S202). As shown in FIG. 7A, the mold is composed of an upper mold 100 and a lower mold 110 that face each other, and the upper mold 100 includes a flat mold surface portion 102 that contacts the first porous body 40 in the battery cell 20. And a sealing portion forming recess 104 subsequent thereto. In the seal portion forming recess 104, two rib recesses 106 in which the outer shapes of the rib protrusions 64 and the recesses 65 of the elastic seal member 60 are reversed and an injection port 107 are formed. The lower mold 110 includes a separator recess 112 that matches the outer shape of the separator 70. In this case, since the separator 70 forms a manifold such as the oxidizing gas discharge manifold 12 together with the elastic seal member 60, the seal part forming recess 104 and the lower mold 110 of the upper mold 100 are slightly larger than the manifold shape. A convex portion 114 is formed. The projection 114 abuts against the separator 70 and seals the manifold of the separator 70 in mold clamping described later.

  Next, the arrangement of the separator 70 in the separator recess 112 of the lower mold 110 (step S204), the arrangement of the second porous body 50 in the arranged separator 70 (step S206), and the arranged second porous body 50. The MEA 30 is placed on the MEA 30 (step S208) and the first porous body 40 is placed on the placed MEA 30 (step S210). In this way, when the separator 70 and the constituent members of the cell constituent member 30 are all disposed with respect to the lower mold 110, the upper mold 100 is clamped to the lower mold 110 with a predetermined mold pressure. The elastic seal member 60 is injection-molded by injecting a material for forming the elastic seal member 60 (for example, the above-described silicon rubber) (step S212). After the upper and lower molds are clamped, as shown in FIG. 7B, the end mold surface of the flat mold surface portion 102, the mold surface of the rib recess 106 in the upper mold 100, and the separator already disposed in the lower mold 110. A cavity 120 is formed by the upper surface of 70 and the side surfaces of the convex portions 114 between the upper and lower molds, and a material for forming the elastic seal member 60 is injected into the cavity 120. The injected material, for example, a liquid rubber such as silicone rubber, forms the elastic seal member 60 through vulcanization.

  In this injection molding, the material for forming the elastic seal member 60 reaches the cavity 120 and surrounds the peripheral edges of the cell constituent member 30 laminated on the separator 70 and the porous body above and below the elastic seal member. 60 is formed. The elastic seal member 60 thus formed includes a stepped portion upper surface portion 61 formed of a material spread between the stepped portion 42 of the first porous body 40 and the mold surface of the flat surface portion 102, and the first porous body. 40 and the cell component 30 (specifically, the protective film 37), a stepped portion lower surface portion 62 formed of a material spread between the second porous body 50 and the cell component 30 (specifically, the protective film 37). ) And a porous body upper surface portion 63 formed of a material that has been distributed between. In this case, since the first porous body 40 includes the sealing portion 41 and the second porous body 50 includes the sealing portion 51, the material for forming the elastic seal member 60 is the same as the first porous body 40. The central part of the second porous body 50 is not impregnated.

  After the injection molding, the upper mold 100 and the lower mold 110 are opened, and the battery cell 20 that is an injection molded product is removed (step S214) to obtain the battery cell 20. A predetermined number of the obtained battery cells 20 are stacked to constitute the fuel cell 10 as described above.

  In the battery cell 20 of the present embodiment described above, the first porous body 40 integrated with the cell constituent member 30 at the periphery thereof by the elastic seal member 60 is elastic to the stepped portion 42 provided thinner than the central side portion. It is located inside the seal member 60. For this reason, the elastic seal member 60 forms a stepped portion upper surface portion 61 on the upper surface side of the stepped portion 42 of the first porous body 40 at the time of molding, and the protective film 37 around the stepped portion 42 and the periphery of the cell constituent member 30. A stepped portion lower surface portion 62 is formed between and provided. Therefore, the elastic seal member 60 sandwiches the step portion 42 that is the peripheral portion of the first porous body 40 in the upper and lower directions in the thickness direction of the porous body. As a result, even if a force that causes the peripheral edge to peel off acts on the first porous body 40, for example, the mold surface of the flat surface portion 102 of the upper mold 100 and the first porous body 40 at the time of demolding Even if the adhesive force acts on the first porous body 40 so that the peripheral edge of the first porous body 40 is peeled off, the elastic seal member 60 is located on the outer surface side in the step portion 42 on the peripheral edge of the porous body. The step portion 42 functions so as to be pressed by the step portion upper surface portion 61 against the above force. Not only the adhesion force at the time of demolding, the same applies even if other forces act to peel the peripheral edge of the first porous body 40. For example, since the battery cell 20 receives a fastening force, the anode-side gas diffusion layer 34 of the cell constituent member 30 has a spring-like action under compression, and the anode-side gas diffusion layer is released when the fastening force is released. 34 exerts a force to lift the first porous body 40, and this force acts to peel the peripheral edge of the first porous body 40. Even with this force, the elastic seal member 60 functions to hold the step portion 42 by the step portion upper surface portion 61. As mentioned above, according to the battery cell 20 of a present Example, peeling of the periphery of the 1st porous body 40 can be prevented with high effectiveness.

  Moreover, in the battery cell 20 of the present embodiment, since the stepped portion 42 is crushed by the press body P into a stepped shape having the stepped portion 43, the strength of the stepped portion 42 can be increased by crushing. For this reason, the pressing effect of the step portion 42 by the step portion upper surface portion 61 of the elastic seal member 60 is increased, and the effectiveness of preventing the peripheral edge of the first porous body 40 from being peeled off is further increased.

  Further, the battery cell 20 of the present embodiment includes a sealing portion 41 inside the stepped portion 42 in the first porous body 40, and the sealing portion 41 impregnates the material for forming the elastic seal member 60. To avoid. For this reason, after preventing peeling of the periphery of the 1st porous body 40 with the elastic seal member 60, the gas diffusion supply in the center side site | part of the 1st porous body 40 is securable.

  And according to the battery cell manufacturing method of a present Example, the battery cell 20 provided with the effectiveness of peeling prevention of the periphery of the 1st porous body 40 can be manufactured easily. And since the manufactured battery cell 20 has already laminated | stacked the cell structural member 30, the 1st porous body 40, and the 2nd porous body 50 which integrated the periphery with the elastic seal member 60 on the separator 70, The fuel cell 10 can be manufactured simply by stacking and fastening the battery cells 20 of the present embodiment, which is advantageous in terms of improving the assembly property of the fuel cell 10 and reducing the manufacturing process.

  Further, in the battery cell 20 of the present embodiment, the step-like step portion 42 is formed on the periphery of the first porous body 40, and thus has the following advantages. FIG. 8 is an explanatory diagram for explaining the advantages of the battery cell 20.

  Because of the fact that the first porous body 40 is a metal porous body, the first porous body 40 usually has burrs at the periphery when cutting into a rectangular shape. As shown in FIG. 8A, if the first porous body 140 has the burr 141 with the burr 141 facing outward, the burr 141 is formed on the separator 70 of the battery cell stacked on the upper side in the figure. Hit it. The burr 141 is crushed when the battery cell is fastened, but the contact state between adjacent battery cells may change, or an inadvertent cavity may be left at the burr crushing location. 8B, if the first porous body 140 has the burr 141 facing the MEA 32 side of the cell constituent member 30, the burr 141 may damage the MEA 32 when the battery cell is fastened. It is feared to invite. If the burr 151 is directed toward the MEA 32 even in the second porous body 150, there is a concern that the burr 141 and the burr 151 may be brought into contact when the battery cell is fastened. Alternatively, as shown in FIG. 8C, if the second porous body 150 has the burr 151 facing the separator 70 side, a cavity that causes a gas path cut is left on the upper surface side of the separator 70. There can be. For this reason, it is necessary to remove burrs together with the cutting of the metal porous body. However, in the battery cell 20 of the present embodiment, since the burrs can be removed automatically when forming the stepped portion 42 at the peripheral edge of the first porous body 40, it is preferable that operations and processes for removing the burrs are unnecessary.

  Next, another embodiment will be described. FIG. 9 is a view corresponding to FIG. 5, and is an explanatory view showing the first porous body 40 </ b> A of the second embodiment together with its production and integration with the elastic seal member 60.

  As shown in the figure, the first porous body 40A includes a bottomed portion 42A that is constricted on the peripheral side of the sealing portion 41, and the bottomed portion 42A is a recess that is recessed in a V shape from the surface of the porous body. It has a portion 43A. In addition, the bottomed portion 42A has continuous pores in the state before the injection molding of the elastic seal member 60, and the bottomed portion 42A is impregnated with the material for forming the elastic seal member 60 through the injection molding. I did it. That is, the bottomed portion 42A is cut by the rotary cutting tool SC as shown in FIG. 9A so that the continuous pores are not crushed. Then, the first porous body 40A having the bottomed portion 42A in a state where the continuous pores remain is set in the mold in place of the first porous body 40 shown in FIG. 7, and the elastic seal member 60 is injection molded. To do. In this way, the continuous pores of the bottomed portion 42A are impregnated with the material for forming the elastic seal member 60 during the injection molding, and the elastic seal member 60 has a depressed portion as shown in FIG. 9B. The step portion upper surface portion 61 is formed so as to fill 43A, and the step portion lower surface portion 62 is formed on the lower surface of the porous body.

  According to the second embodiment using the first porous body 40A described above, the above-described effects can be achieved and the following advantages can be obtained. First, in the second embodiment, since the elastic seal member 60 has the depressed portion 43A filled with the stepped portion upper surface portion 61, even if a rightward force in FIG. The elastic seal member 60 can be held against the force. Further, since the depressed portion 43A is filled with the stepped portion upper surface portion 61 and the bottomed portion 42A is pressed by the stepped portion upper surface portion 61, it is desirable for improving the effectiveness of preventing the peripheral edge of the porous body 40 from peeling off. In addition, the elastic seal member 60 is formed by impregnating and vulcanizing the stepped portion upper surface 61 filled with the depressed portion 43A and the stepped portion lower surface 62 on the lower surface side of the bottomed portion 42A into the continuous pores of the bottomed portion 42A. It can be integrated with the forming material. Therefore, the first porous structure includes the pressing effect of the bottomed portion 42A by the stepped portion upper surface portion 61 of the elastic seal member 60 and the anchor effect by the material for forming the elastic seal member 60 impregnated and vulcanized in the bottomed portion 42A. The effectiveness of preventing the peripheral edge of the body 40A from peeling off is further enhanced. In this case, it is preferable that the bottomed portion 42A is impregnated with the material for forming the elastic seal member 60 up to the inside of the bottomed portion 42A, but if it occurs near the outer surface of the bottomed portion 42A, the outer surface thereof An anchor effect can be obtained. In this embodiment, the depressed portion 43A in the bottomed portion 42A is depressed in a V shape. However, the depressed shape of the depressed portion 43A is not limited to the V shape, and is a U shape or a concave shape with a pin angle. Can do.

  FIG. 10 is a view corresponding to FIG. 4, and is an explanatory view showing a part of the battery cell 20 </ b> A of the third embodiment in an enlarged manner while viewing a cross-sectional view.

  As shown in the drawing, the first porous body 40B provided in the battery cell 20A of the third embodiment includes a pore remaining part 44 between the sealing part 41 and the step part 42 described above. This pore remaining part 44 has continuous pores in the state before the injection molding of the elastic seal member 60 in the same manner as the bottomed part 42A described above, and is impregnated with a material for forming the elastic seal member 60 after injection molding. Vulcanize. In order to obtain such a first porous body 40B, the formation site of the sealing portion 41 by the resin ejection nozzle S described in FIG. By the formation of the stepped portion 42 by the body P, the sealing portion 41, the pore remaining portion 44, and the stepped portion 42 are arranged in this order on the peripheral edge of the first porous body 40B. Then, instead of the first porous body 40 shown in FIG. 7, the first porous body 40B having the pore-remaining portions 44 where the continuous pores remain is set in a mold, and the elastic seal member 60 is injection-molded. By so doing, the continuous pores of the pore remaining part 44 are impregnated with the material for forming the elastic seal member 60 and vulcanized during injection molding.

  Even with the battery cell 20A of the third embodiment using the first porous body 40B described above, the same effects as those of the second embodiment described above can be obtained. That is, the step portion upper surface portion 61 that acts to hold down the step portion 42 is anchored by being connected to the step portion lower surface portion 62 with the material for forming the elastic seal member 60 impregnated and vulcanized into the pore remaining portion 44. Alternatively, due to the anchor effect at the interface between the pore remaining portion 44 and the stepped portion upper surface portion 61, the effectiveness of preventing the peripheral edge of the first porous body 40B from peeling off is further enhanced.

  FIG. 11 is a view corresponding to FIG. 10, and is an explanatory view showing a part of the battery cell 20 </ b> B of the fourth embodiment in an enlarged manner while viewing a cross-sectional view. In this embodiment, the second porous body 50A joined to the separator 70 is characterized in that a depressed portion or a stepped portion is formed.

  As shown in the figure, the second porous body 50A included in the battery cell 20B includes a sealing portion 51 similar to the sealing portion 41 included in the first porous body 40 described above at the periphery of the porous body. A recessed portion 53 and an outermost peripheral edge portion 52 are provided side by side with the stopper 51. The depressed portion 53 is formed in a V shape like the depressed portion 43 </ b> A of the first porous body 40 </ b> A, and a central portion of the second porous body 50 corresponding to a step corresponding to the depth of the V shape. Thinner. The outermost peripheral edge part 52 is formed with the same thickness as the central part of the second porous body 50. The outermost peripheral edge portion 52 and the depressed portion 53 have continuous pores in the state before the injection molding of the elastic seal member 60, like the bottomed portion 42A of the first porous body 40A. The material for forming the elastic seal member 60 is impregnated and vulcanized. In manufacturing the battery cell 20B, the second porous body 50A having the outermost peripheral edge portion 52 and the depressed portion 53 in a state where the continuous pores remain is replaced with the second porous body 50 shown in FIG. Set in the mold. At this time, the elastic seal member 60 is injection-molded after the depressed portion 53 faces the MEA 32 side of the cell constituent member 30. In this way, the continuous pores of the outermost peripheral portion 52 and the depressed portion 53 are impregnated with the material for forming the elastic seal member 60 during the injection molding.

  When the material for forming the elastic seal member 60 is injected, the material for forming the elastic seal member 60 flows under the injection pressure. Due to this material flow, the MEA 32 may receive injection pressure and bend as shown in the figure together with the protective film 37, and the protective film 37 of the MEA 32 may ride on the peripheral surface of the second porous body. If the protective film 37 of the MEA 32 rides on the surface of the second porous body and does not take any measures while covering the peripheral surface, the base region 60S of the MEA 32 on the peripheral edge side of the cathode-side gas diffusion layer 36 is formed. There is a concern that the material for forming the elastic seal member 60 will not spread and leave a gap in the base region 60S.

  However, in the battery cell 20B of the fourth embodiment using the above-described second porous body 50A, as shown in the enlarged portion of FIG. 11, the elastic seal member 60 is accompanied by the injection of the material for forming the elastic seal member 60. As shown by the arrow X in the figure, the forming material is sequentially impregnated from the outermost peripheral edge portion 52 side having continuous pores into the continuous pores of the portion and the adjacent depressed portion 53 as indicated by an arrow X in the figure. Then, the material for forming the elastic seal member 60 escapes from the surface of the depressed portion 53 and reaches the base region 60S of the MEA 32 on the peripheral edge side of the cathode side gas diffusion layer 36. That is, the injected material for forming the elastic seal member 60 is impregnated in the outermost peripheral edge portion 52 and the depressed portion 53, and the base region 60S is filled and vulcanized. For this reason, according to the battery cell 20B of the fourth embodiment, since no gap is left in the base region 60S, there is a problem in the case where a void remains in the base region 60S, for example, due to retention / concentration of generated water in the gap. It is possible to avoid the deterioration of parts and the accompanying performance degradation. Further, the elastic seal member 60 has an anchor effect by a material for forming the elastic seal member 60 impregnated and vulcanized in the seal member portion that fills the base region 60S and the depressed portion 53, the outermost peripheral portion 52, and the depressed portion 53, It is possible to ensure the integration of the cell constituent member 30 and the peripheral edges of the upper and lower porous bodies.

  The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the cell component 30 has the MEA 32, the upper and lower anode-side gas diffusion layers 34, and the cathode-side gas diffusion layer 36, but may not have the anode-cathode-side gas diffusion layers. . In addition, the MEA 32 has the protective film 37 on the periphery thereof, but may have a form without the protective film 37.

  Moreover, although the 1st porous body 40 and the 2nd porous body 50 were made into the different form, the same thing can also be used. For example, in the battery cell 20A shown in FIG. 10, the second porous body 50 is a porous body having the same shape as the first porous body 40B, and the step 43 of the step portion 42 is positioned on the surface side of the separator 70. It can also be. Thus, even if the MEA 32 is curved as described above, the material for forming the elastic seal member 60 passes through the portion impregnated in the pore remaining portion 44 through the gap between the step portion 42 and the surface of the separator 70. After that, the base region 60S is reached and the region can be filled with the material for forming the elastic seal member 60.

  In the battery cell 20B shown in FIG. 11, the first porous body 40 may be a porous body having the same shape as the second porous body 50A so that the depressed portion 53 is positioned on the outer surface side of the battery cell. . In this way, the elastic seal member 60 is located on the outer surface side of the battery cell, and the depression 53 is thinned by the material for forming the elastic seal member 60 and is thinned by the V-shaped step. The peripheral edge of the porous body can be prevented with high effectiveness by the anchor effect of the pressing and the sealing member portion, the outermost peripheral edge portion 52 and the material for forming the elastic seal member 60 impregnated and vulcanized in the depressed portion 53.

  4 and 10, the step portion 42 is formed on the lower surface side of the periphery of the first porous body. However, if the step portion 42 is formed with the step 43 from the outer surface side of the battery cell, the step portion 42 is It can also be formed at the center of the peripheral edge of one porous body.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 11 ... Oxidation gas supply manifold 12 ... Oxidation gas discharge manifold 13 ... Fuel gas supply manifold 14 ... Fuel gas discharge manifold 15 ... Coolant supply manifold 16 ... Coolant discharge manifold 20, 20A-20B ... Battery cell 30 ... Cell component 34 ... Anode-side gas diffusion layer 36 ... Cathode-side gas diffusion layer 37 ... Protective film 40, 40A to 40B ... First porous body 41 ... Sealing part 42 ... Step part 42A ... Bottom part 43 ... Step 43A ... recessed part 44 ... remaining pore part 50, 50A ... second porous body 51 ... sealing part 52 ... outermost peripheral part 53 ... recessed part 60 ... elastic seal member 60S ... base region 61 ... stepped part upper surface part 62 ... step Lower part of part 63 ... Upper surface part of porous body 64 ... Rib protrusion 65 ... Recess 70 ... Separator 7 DESCRIPTION OF SYMBOLS 1 ... 1st plate 72 ... 2nd plate 73 ... Intermediate | middle plate 100 ... Upper mold | type 102 ... Flat mold | type surface part 104 ... Sealing part formation recess 106 ... Rib recess 107 ... Injection port 110 ... Lower mold 112 ... Separator recess 114 ... Projection 120 ... Cavity S ... Resin ejection nozzle P ... Press body SC ... Rotary cutting tool

Claims (8)

A battery cell as a power generation unit of a fuel cell,
A cell constituent member including a membrane electrode assembly in which a catalyst electrode is joined to an electrolyte membrane;
A porous body forming a gas diffusion supply path with continuous pores;
An elastic seal member that surrounds and integrates the cell constituent member and the porous body superposed on both sides thereof over the periphery thereof;
The porous body includes a peripheral portion that is thinner than a portion inside the periphery of the porous body at the periphery of the porous body, and the peripheral portion is positioned inside the elastic seal member.   The porous body is provided with a sealing portion on the peripheral edge side of the porous body, which is formed by filling the continuous pores so as to avoid impregnation of the material for forming the elastic seal member into the porous body. The battery cell according to claim 1, wherein the peripheral portion is located on the peripheral side of the portion.   3. The battery cell according to claim 1, wherein the peripheral portion has a stepped portion that is formed into a step shape by crushing the periphery of the porous body.   The peripheral edge portion on the peripheral side of the sealing portion has an impregnation portion in which the continuous pores are impregnated with the material for forming the elastic seal member between the stepped portion and the sealing portion. The battery cell of description.   The battery cell according to claim 1, wherein the peripheral portion has a bottomed portion constricted at a peripheral edge of the porous body.   The said peripheral part has the peripheral part extended from the said bottomed part to the said porous body periphery in the state which impregnated the formation material of the said elastic seal member in the said continuous pore of this peripheral part. Battery cell. The battery cell according to any one of claims 1 to 6,
Furthermore, a separator is joined to one side of the porous body overlapping the cell constituent member,
A battery cell in which at least one of the porous body on the separator side and the other porous body has the peripheral portion.   A fuel cell comprising a plurality of the battery cells according to claim 7 stacked thereon.

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