JP5318461B2 - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To excellently suppress deformation due to buckling of a casing at the time of application of an external force in lamination direction of the stack to the fuel cell stack; and to simplify the structure. <P>SOLUTION: The fuel cell stack 10 includes a laminate 14 and is supported integrally by a casing 24 including end plates 20a, 20b as an end plate. Side plates 60a-60d to constitute the casing 24 include bumper structures 82a-82d for absorbing an impact when an external force is applied in a lamination direction of the laminate 14. The bumper structures 82a-82d respectively have a plurality of circular apertures 84a-84d provided in the side plates 60a-60d. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a fuel cell stack in which a stacked body in which a plurality of electrolyte / electrode structures in which a pair of electrodes are provided on both sides of an electrolyte and a plurality of separators are stacked is housed in a box-shaped casing.

  For example, a polymer electrolyte fuel cell employs an electrolyte membrane (electrolyte) made of a polymer ion exchange membrane. A fuel cell is configured by sandwiching an electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are disposed on both sides of the electrolyte membrane with a separator.

  Normally, this fuel cell is used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) is stacked in order to obtain a desired power generation. In this fuel cell stack, the stacked fuel cells need to be reliably pressurized and held in order to prevent an increase in the internal resistance of the fuel cell and a decrease in the sealing performance of the reaction gas.

  Thus, for example, a fuel cell disclosed in Patent Document 1 is known. As shown in FIG. 9, the fuel cell includes a laminate 3 in which unit cells 2 each having an electrolyte membrane and electrodes sandwiching the electrolyte membrane are laminated. End plates 4 and 5 are provided on both sides in the stacking direction of the laminate 3, and a disc spring 6 is provided between the end plate 5 and the laminate 3.

  On each side surface along the stacking direction of the laminate 3, a metal tension plate 7 is provided that applies a surface pressure to the laminate 3 and holds the surface pressure.

JP 2003-203670 A

  By the way, in the above fuel cell, in particular, when used for in-vehicle use, it is easy to receive a load from the outside. At this time, if a compressive load is applied to the fuel cell in the stacking direction of the single cells 2, the tension plate 7 having a lower strength than the end plates 4 and 5 may be buckled. Thereby, the tension plate 7 is deformed to the laminated body 3 side (inner side) or the side away from the laminated body 3 (outer side), and damage of the unit cell 2 or external harness and peripheral parts is caused. There's a problem.

  The present invention solves this type of problem, and when an external force is applied to the fuel cell stack in the stacking direction of the stack, the deformation due to the buckling of the casing is well suppressed and the configuration is simplified. An object of the present invention is to provide a fuel cell stack capable of achieving the above.

  The present invention relates to a fuel cell stack in which a laminated body in which a plurality of electrolyte / electrode structures each having a pair of electrodes provided on both sides of an electrolyte and a plurality of separators are stacked is housed in a box-shaped casing.

The casing includes an end plate disposed at both ends in the stacking direction of the laminate, a plurality of side plates disposed at a side of the laminate, a connection pin that connects the end plate and the side plate, and the connection pin. And a hinge part to be inserted. All the side plates are provided with a buffer structure having rigidity lower than that of the side plates, and the buffer structures are shocked by being concentratedly deformed when an external force is applied to the casing in the stacking direction of the stacked body. And the deformation due to the buckling of the side plate is suppressed .

  Moreover, it is preferable that a buffer structure has an opening part provided in a side plate.

  Furthermore, it is preferable that the buffer structure has a buffer member that divides the side plate in the stacking direction and that is disposed in the divided portion and has rigidity lower than that of the side plate.

  In the present invention, when an external force (compression force) is applied to the fuel cell stack in the stacking direction, an impact can be absorbed via the buffer structure provided on the side plate. For this reason, it is possible to satisfactorily suppress deformation due to buckling of the side plate and simplify the configuration.

  FIG. 1 is a partially exploded schematic perspective view of a fuel cell stack 10 according to the first embodiment of the present invention, and FIG. 2 is a partial sectional side view of the fuel cell stack 10. The fuel cell stack 10 can be preferably used as an in-vehicle fuel cell stack.

  The fuel cell stack 10 includes a stacked body 14 in which a plurality of unit cells 12 are stacked in the horizontal direction (arrow A direction). A terminal plate 16a, an insulating plate 18 and an end plate 20a are sequentially disposed at one end in the stacking direction (arrow A direction) of the stacked body 14 toward the outside. At the other end in the stacking direction of the stacked body 14, a terminal plate 16b, an insulating spacer member 22 (the insulating plate 18 may be used) and an end plate 20b are sequentially disposed outward. The fuel cell stack 10 is integrally held by a casing 24 including end plates 20a and 20b each having a rectangular shape as end plates.

  As shown in FIGS. 2 and 3, each unit cell 12 includes an electrolyte membrane / electrode structure (electrolyte / electrode structure) 30, and a thin plate-shaped first and second sandwiching the electrolyte membrane / electrode structure 30. Second metal separators 32 and 34 are provided. Instead of the first and second metal separators 32 and 34, for example, a carbon separator may be used.

  An oxidant gas supply for supplying an oxidant gas, for example, an oxygen-containing gas, communicates with each other in the arrow A direction at one end edge of the unit cell 12 in the long side direction (the arrow B direction in FIG. 3). A communication hole 36a, a cooling medium supply communication hole 38a for supplying a cooling medium, and a fuel gas discharge communication hole 40b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge in the long side direction of the unit cell 12 communicates with each other in the direction of arrow A, and a fuel gas supply communication hole 40a for supplying fuel gas, and a cooling medium discharge communication hole for discharging the cooling medium. 38b and an oxidizing gas discharge communication hole 36b for discharging the oxidizing gas are provided.

  The electrolyte membrane / electrode structure 30 includes, for example, a solid polymer electrolyte membrane 42 in which a perfluorosulfonic acid thin film is impregnated with water, and an anode side electrode 44 and a cathode side electrode 46 that sandwich the solid polymer electrolyte membrane 42. With.

  The anode side electrode 44 and the cathode side electrode 46 are uniformly coated with a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface thereof. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 42.

  On the surface 32a of the first metal separator 32 facing the electrolyte membrane / electrode structure 30, there is a fuel gas channel 48 that communicates with the fuel gas supply communication hole 40a and the fuel gas discharge communication hole 40b and extends in the arrow B direction. It is formed. On the surface 32b of the first metal separator 32, there is formed a cooling medium flow path 50 that communicates with the cooling medium supply communication hole 38a and the cooling medium discharge communication hole 38b and extends in the arrow B direction.

  The surface 34a of the second metal separator 34 facing the electrolyte membrane / electrode structure 30 is provided with an oxidant gas flow path 52 extending in the direction of arrow B. The oxidant gas flow path 52 is formed of an oxidant gas. The supply communication hole 36a communicates with the oxidant gas discharge communication hole 36b. A cooling medium flow path 50 is integrally formed on the surface 34 b of the second metal separator 34 so as to overlap the surface 32 b of the first metal separator 32.

  A first seal member 54 is integrally formed on the surfaces 32 a and 32 b of the first metal separator 32 around the outer peripheral edge of the first metal separator 32. A second seal member 56 is integrally formed on the surfaces 34 a and 34 b of the second metal separator 34 around the outer peripheral edge of the second metal separator 34.

  As shown in FIG. 2, a seal 57 is interposed between the first and second seal members 54 and 56 in order to prevent the outer periphery of the solid polymer electrolyte membrane 42 from directly contacting the casing 24. Is done.

  As shown in FIG. 1, rod-shaped terminal portions 58a and 58b projecting in the stacking direction are formed at substantially the center portions of the terminal plates 16a and 16b. For example, a load such as a traveling motor is connected to the terminal portions 58a and 58b.

  The casing 24 is an angle member that connects end plates 20a and 20b, which are end plates, a plurality of side plates 60a to 60d disposed on the side of the laminated body 14, and end portions of the side plates 60a to 60d that are close to each other. 62a to 62d, and connecting pins 64a and 64b having different lengths for connecting the end plates 20a and 20b and the side plates 60a to 60d. The side plates 60a to 60d are made of, for example, a thin metal plate.

  Two first hinge portions 66a and 66b project from the upper and lower sides of the end plates 20a and 20b, respectively, and two first hinge portions 66c and 66d project from the both sides. The Holes 67a to 67d are formed through the first hinge portions 66a to 66d.

  Two second hinge portions 70a and 70b are formed at both ends in the longitudinal direction (arrow A direction) of the side plates 60a and 60c arranged on both sides in the arrow B direction of the laminate 14. Three second hinge portions 72a and 72b are formed at both ends in the longitudinal direction of the side plates 60b and 60d arranged on the upper and lower sides of the laminate 14 respectively. Holes 71a and 71b are formed in the second hinge portions 70a and 70b, and holes 73a and 73b are formed in the second hinge portions 72a and 72b.

  Between the second hinge portions 70a and 70b of the side plates 60a and 60c, first hinge portions 66c and 66d on both sides of the end plates 20a and 20b are arranged, and a short connecting pin 64a is integrally formed therewith. Inserted.

  Similarly, the second hinge portions 72a and 72b of the side plates 60b and 60d are alternately arranged with the first hinge portions 66a and 66b on the upper and lower sides of the end plates 20a and 20b, and a long connecting pin 64b is provided on these. Inserted integrally.

  As shown in FIG. 1, the side plates 60 a to 60 d are formed with a plurality of screw holes 74 at both edges in the short direction, and the sides of the angle members 62 a to 62 d correspond to the screw holes 74. Thus, the hole 76 is formed. When the screws 77 inserted into the holes 76 are screwed into the screw holes 74, the side plates 60a to 60d are fixed to each other via the angle members 62a to 62d. Thereby, the casing 24 is configured (see FIG. 4).

  As shown in FIGS. 1 and 4, attachment plate members 80 are fixed to both ends of the side plate 60 b in the direction of arrow A, and three second pins for inserting connection pins 64 b are inserted into the attachment plate member 80. The hinge part 72a is joined. Note that the second hinge portion 72a may be directly joined to the side plate 60b as long as the joining strength and shape can be maintained.

  As shown in FIG. 1, the side plates 60a, 60c, and 60d are configured in the same manner as the side plate 60b described above, and a detailed description thereof is omitted. Further, the end plates 20a and 20b may be configured similarly to the side plate 60b as necessary.

  The side plates 60 a to 60 d are provided with buffer structures 82 a to 82 d for absorbing an impact when an external force is applied in the stacking direction (arrow A direction) of the stacked body 14. The buffer structures 82a to 82d have a plurality of circular openings 84a to 84d provided in the side plates 60a to 60d, respectively. The numbers, dimensions, arrangement positions, etc. of the openings 84a to 84d are set in accordance with the area and thickness of the side plates 60a to 60d.

  The shapes of the openings 84a to 84d can be set to various shapes such as a rectangular shape, an oval shape, an elliptical shape, a triangular shape, or a polygonal shape in addition to a circular shape.

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

  In the fuel cell stack 10, first, as shown in FIG. 4, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas supply communication hole 36a of the end plate 20a, and hydrogen is supplied to the fuel gas supply communication hole 40a. Fuel gas such as contained gas is supplied. Further, a coolant such as pure water or ethylene glycol is supplied to the coolant supply passage 38a. For this reason, in the stacked body 14, the oxidant gas, the fuel gas, and the cooling medium are supplied in the arrow A direction to the plurality of unit cells 12 stacked in the arrow A direction.

  As shown in FIG. 3, the oxidant gas is introduced into the oxidant gas flow path 52 of the second metal separator 34 through the oxidant gas supply communication hole 36 a, and along the cathode side electrode 46 of the electrolyte membrane / electrode structure 30. Move. On the other hand, the fuel gas is introduced into the fuel gas passage 48 of the first metal separator 32 through the fuel gas supply communication hole 40 a and moves along the anode side electrode 44 of the electrolyte membrane / electrode structure 30.

  Therefore, in each electrolyte membrane / electrode structure 30, the oxidant gas supplied to the cathode side electrode 46 and the fuel gas supplied to the anode side electrode 44 are consumed by an electrochemical reaction in the electrode catalyst layer, Power generation is performed.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 46 flows along the oxidant gas discharge communication hole 36b, and then is discharged to the outside from the end plate 20a. Similarly, the fuel gas consumed by being supplied to the anode side electrode 44 is discharged to the fuel gas discharge communication hole 40b, flows, and is discharged from the end plate 20a to the outside.

  The cooling medium flows in the direction of arrow B after being introduced into the cooling medium flow path 50 between the first and second metal separators 32 and 34 from the cooling medium supply communication hole 38a. The cooling medium cools the electrolyte membrane / electrode structure 30, and then moves through the cooling medium discharge communication hole 38b and is discharged from the end plate 20a.

  In this case, in the first embodiment, as shown in FIG. 1, the side plates 60 a to 60 d are provided with buffer structures 82 a to 82 d, and the buffer structures 82 a to 82 d are each provided in a plurality of side plates 60 a to 60 d. Have openings 84a to 84d. For this reason, as for side plate 60a-60d, the intensity | strength (rigidity) vicinity of the site | part in which opening part 84a-84d is provided is falling rather than the intensity | strength (rigidity) of another site | part.

  Therefore, in the fuel cell stack 10, for example, when used for in-vehicle use, when a load (external force) F is applied in the stacking direction (arrow A direction), as shown in FIG. In particular, the vicinity of the openings 84a to 84d arranged at positions close to the hinge structure is concentrated and easily deformed. It is because it is easy to receive power.

  As a result, the load in the stacking direction applied to the fuel cell stack 10 can be absorbed via the buffer structures 82a to 82d, and in particular, deformation due to buckling of the thin plate-like side plates 60a to 60d is satisfactorily suppressed. At the same time, it is possible to simplify the configuration. Therefore, it is effective that the side plates 60a to 60d are deformed inward and the unit cell 12 is damaged, or the side plates 60a to 60d are deformed outward to damage unillustrated harnesses and peripheral parts. It becomes possible to stop.

  FIG. 6 is a partially exploded schematic perspective view of a fuel cell stack 90 according to a second embodiment of the present invention, and FIG. 7 is a partial schematic perspective view of the fuel cell stack 90. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fuel cell stack 90 includes a casing 92, and the casing 92 includes end plates 20a and 20b and side plates 94a to 94d. The side plates 94 a to 94 d are provided with buffer structures 96 a to 96 d for absorbing an impact when an external force is applied in the stacking direction (arrow A direction) of the stacked body 14.

  The buffer structures 96a to 96d each have side plates 94a to 94d divided into a plurality of plate portions 98a to 98d in the stacking direction, and buffer members 100a to 100d disposed at the respective divided portions. The buffer members 100a to 100d are set to be lower in rigidity than the plate portions 98a to 98d by selecting the plate thickness, material, shape, and the like. As the buffer members 100a to 100d, for example, a rubber material or a resin material is used.

  In the second embodiment configured as described above, when a load F in the stacking direction is applied to the fuel cell stack 90, as shown in FIG. 8, the cushioning members 100a to 100a are less rigid than the plate portions 98a to 98d. 100d contracts and deforms. For this reason, the load in the stacking direction applied to the fuel cell stack 90 can be absorbed via the buffer structures 96a to 96d.

  As a result, in the second embodiment, the deformation due to buckling of the thin plate-like side plates 94a to 94d can be satisfactorily suppressed, and the configuration can be simplified. Similar effects can be obtained.

1 is a partially exploded schematic perspective view of a fuel cell stack according to a first embodiment of the present invention. It is a partial cross section side view of the said fuel cell stack. It is a disassembled perspective explanatory drawing of the unit cell which comprises the said fuel cell stack. It is a perspective view of the fuel cell stack. It is operation | movement explanatory drawing when the load of the lamination direction is provided to the said fuel cell stack. FIG. 4 is a partially exploded schematic perspective view of a fuel cell stack according to a second embodiment of the present invention. It is a partial perspective explanatory view of the fuel cell stack. It is operation | movement explanatory drawing when the load of the lamination direction is provided to the said fuel cell stack. 2 is an explanatory diagram of a fuel cell disclosed in Patent Document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 90 ... Fuel cell stack 12 ... Unit cell 14 ... Laminated body 20a, 20b ... End plate 24, 92 ... Casing 30 ... Electrolyte membrane electrode structure 32, 34 ... Metal separator 42 ... Solid polymer electrolyte membrane 44 ... Anode Side electrode 46 ... Cathode side electrode 48 ... Fuel gas flow path 50 ... Cooling medium flow path 52 ... Oxidant gas flow path 54, 56 ... Seal members 60a-60d, 94a-94d ... Side plates 64a, 64b ... Connecting pins 66a-66d , 70a, 70b, 72a, 72b ... hinges 82a to 82d, 96a to 96d ... buffer structures 84a to 84d ... openings 98a to 98d ... plate parts 100a to 100d ... buffer members

Claims (4)

A fuel cell stack in which a stacked body in which a plurality of separators are stacked in an electrolyte / electrode structure in which a pair of electrodes are provided on both sides of an electrolyte is housed in a box-shaped casing,
The casing includes end plates disposed at both ends in the stacking direction of the stacked body,
A plurality of side plates disposed on the side of the laminate;
A connecting pin for connecting the end plate and the side plate;
A hinge part for inserting the connecting pin;
With
All the side plates are provided with a buffer structure having rigidity lower than that of the side plates,
The buffer structure, when an external force is applied to the laminating direction of the laminated body to the casing, absorb the shock by deforming focused and characterized that you suppress deformation due to buckling of the side plates Fuel cell stack.   2. The fuel cell stack according to claim 1, wherein the buffer structure has an opening provided in the side plate.   3. The fuel cell stack according to claim 2, wherein the opening has a circular shape.   2. The fuel cell stack according to claim 1, wherein the buffer structure divides the side plate in the stacking direction, and has a buffer member disposed in the divided portion and having rigidity lower than that of the side plate. Battery stack.

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