JP2010140665A - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To actualize simple and economical construction for effectively reducing an external load, enabling fastening and holding, and improving vibration resistance and impact resistance. <P>SOLUTION: In this fuel cell stack 10, a stack 14 is provided which has a plurality of unit cells 12 stacked in the horizontal direction. At both ends of the stack 14 in the stacking direction, terminal plates 16a, 16b, insulating plates 18a, 18b, and end plates 20a, 20b are arranged. The fuel cell stack 10 includes an elastic rubber belt 60 circulating from the stack 14 to the outer peripheries of the end plates 20a, 20b in the stacking direction. The elastic rubber belt 60 is formed in an endlessly cylindrical shape, and its inner peripheral face is formed as a flat-shape 62. On the outer peripheral face of the elastic rubber belt 60, a plurality of elastic protruded portions 64 are provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a unit cell having an electrolyte / electrode structure in which a pair of electrodes are provided on both sides of an electrolyte and a separator, and includes a stacked body in which a plurality of the unit cells are stacked, and stacking the stacked body The present invention relates to a fuel cell stack in which end plates are disposed at both ends in the direction.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (an electrolyte / electrode structure) in which an anode electrode and a cathode electrode are disposed on both sides of an electrolyte membrane (electrolyte) made of a polymer ion exchange membrane, respectively. ) (MEA) is provided with a unit cell sandwiched between separators.

  This type of fuel cell is usually used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) of unit cells are stacked in order to obtain a desired power generation when used for in-vehicle use. Yes. At that time, the fuel cell stack, for example, accommodates a stack in which a predetermined number of unit cells are stacked in a box-shaped casing, tightens between end plates with tie rods, or surrounds the stack with a band. It is tightened.

  For example, in the fuel cell stack disclosed in Patent Document 1, as shown in FIG. 8, a plurality of fuel cell assemblies 3 are inserted between a pair of end plate assemblies 1 and 2. The end plate assemblies 1 and 2 and the plurality of stacked fuel cell assemblies 3 are surrounded by the compression band 4 so that a compressive force is applied in the stacking direction.

  In addition, the fuel cell disclosed in Patent Document 2 describes a technique in which a stack of unit cells is pressed and bound using a band.

Special table 2001-504632 gazette JP-A 61-273873

  In Patent Document 1, the compression band 4 is used, while in Patent Document 2, a similar band is used to simplify the tightening mechanism. However, when an external load is applied to the fuel cell stack, the laminate is directly affected by the external load. Thereby, the laminated body cannot hold a desired fastening state by an external load, and there is a problem that it is weak against vibration and impact.

  The present invention solves this type of problem, and with a simple and economical configuration, it can effectively relax external loads to maintain a desired fastening state, and improve vibration resistance and impact resistance. An object of the present invention is to provide a fuel cell stack capable of achieving the above.

  The present invention provides a unit cell having an electrolyte / electrode structure in which a pair of electrodes are provided on both sides of an electrolyte and a separator, and includes a stacked body in which a plurality of the unit cells are stacked, and stacking the stacked body The present invention relates to a fuel cell stack in which end plates are disposed at both ends in the direction.

  The fuel cell stack includes an elastic rubber belt that circulates the outer periphery of the laminate and the end plate in the stacking direction and applies a tightening load between the end plates, and the elastic rubber belt is configured in a seamless cylindrical shape. The inner peripheral surface of the elastic rubber belt has a flat surface shape, and a plurality of elastic protrusions are provided on the outer peripheral surface of the elastic rubber belt.

  In addition, it is preferable that the elastic protrusions extend in the width direction of the elastic rubber belt and are spaced apart by a predetermined interval in the circumferential direction of the elastic rubber belt.

  Further, it is preferable that the elastic protrusions extend in the circumferential direction of the elastic rubber belt and are spaced apart by a predetermined interval in the width direction of the elastic rubber belt.

  According to the present invention, the elastic rubber belt has no joints, and the inner peripheral surface on the laminated body side has a flat surface shape. For this reason, it is possible to favorably disperse the surface pressure with respect to the laminated body, and it is possible to prevent tightening failure due to concentration of the surface pressure.

  In addition, a plurality of elastic protrusions are provided on the outer peripheral surface of the elastic rubber belt. Therefore, the external load is dispersed and absorbed by the elastic deformation of the elastic protrusion, and the external load can be effectively relaxed. Thereby, while being able to perform desired fastening holding | maintenance, a laminated body can improve vibration resistance and impact resistance.

  FIG. 1 is a schematic perspective view of a fuel cell stack 10 according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional side view of the fuel cell stack 10.

  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 18a, and an end plate 20a are disposed outward at one end of the stacked body 14 in the stacking direction (arrow A direction). A terminal plate 16b, an insulating plate 18b, and an end plate 20b are disposed outwardly at the other end of the stacked body 14 in the stacking direction. The thickness of the insulating plate 18b is selected in order to adjust the tightening load of the entire fuel cell stack 10.

  As shown in FIG. 3, each unit cell 12 includes an electrolyte membrane / electrode structure (electrolyte / electrode structure) 22, a cathode side separator 24 and an anode side separator 26 that sandwich the electrolyte membrane / electrode structure 22. Is provided. The cathode side separator 24 and the anode side separator 26 are made of metal separators, but may be made of carbon separators, for example.

  One end edge of the unit cell 12 in the direction of arrow B communicates with each other in the direction of arrow A to supply an oxidant gas supply communication hole 28a for supplying an oxidant gas, for example, an oxygen-containing gas, and a cooling medium. A cooling medium supply communication hole 30a and a fuel gas discharge communication hole 32b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided.

  The other end edge of the unit cell 12 in the direction of the arrow B communicates with each other in the direction of the arrow A, the fuel gas supply communication hole 32a for supplying the fuel gas, and the cooling medium discharge communication hole for discharging the cooling medium. 30b and an oxidant gas discharge communication hole 28b for discharging the oxidant gas are provided.

  As shown in FIGS. 2 and 3, for example, an oxidant gas flow path 36 extending in the direction of arrow B is provided on the surface 24 a of the cathode separator 24 on the electrolyte membrane / electrode structure 22 side. The oxidant gas flow path 36 communicates with the oxidant gas supply communication hole 28a and the oxidant gas discharge communication hole 28b. A cooling medium flow path 38 is formed on the surface 24 b opposite to the surface 24 a of the cathode separator 24. The cooling medium flow path 38 communicates with the cooling medium supply communication hole 30a and the cooling medium discharge communication hole 30b.

  On the surface 26a of the anode separator 26 on the electrolyte membrane / electrode structure 22 side, there is a fuel gas flow path 40 that communicates with the fuel gas supply communication hole 32a and the fuel gas discharge communication hole 32b and extends in the direction of arrow B. It is formed. A cooling medium flow path 38 communicating with the cooling medium supply communication hole 30a and the cooling medium discharge communication hole 30b by overlapping the surface 24b of the cathode side separator 24 is formed on the surface 26b opposite to the surface 26a of the anode side separator 26. It is formed.

  The cathode-side separator 24 is integrally molded with a first seal member 42 on a thin metal plate, and the anode-side separator 26 is integrally molded with a second seal member 44 on a thin metal plate.

  The electrolyte membrane / electrode structure 22 includes, for example, a solid polymer electrolyte membrane (electrolyte) 46 in which a perfluorosulfonic acid thin film is impregnated with water, a cathode-side electrode 48 and an anode sandwiching the solid polymer electrolyte membrane 46 Side electrode 50.

  The cathode side electrode 48 and the anode side electrode 50 are formed by uniformly applying a gas diffusion layer made of carbon paper or the like and porous carbon particles carrying a platinum alloy supported on the surface of the gas diffusion layer. An electrode catalyst layer. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 46.

  As shown in FIG. 1, at one end edge of the end plate 20a in the arrow B direction, an oxidant gas inlet 52a that communicates with the oxidant gas supply communication hole 28a, and a cooling medium inlet 54a that communicates with the cooling medium supply communication hole 30a. , And a fuel gas outlet 56b communicating with the fuel gas discharge communication hole 32b.

  At the other end edge of the end plate 20a in the direction of arrow B, a fuel gas inlet 56a that communicates with the fuel gas supply communication hole 32a, a cooling medium outlet 54b that communicates with the cooling medium discharge communication hole 30b, and an oxidant gas discharge communication hole. An oxidant gas outlet 52b communicating with 28b is provided.

  As shown in FIGS. 1 and 2, the fuel cell stack 10 circulates the outer periphery of the end plates 20a and 20b from the stack 14 in the stacking direction (arrow A direction), and applies a tightening load between the end plates 20a and 20b. An elastic rubber belt 60 is provided. The upper and lower end surfaces of the end plates 20a, 20b are provided with rounds (R) corresponding to the portions that are in sliding contact with the elastic rubber belt 60.

  The elastic rubber belt 60 is made of an elastic rubber member, and resin fibers and metal fibers are provided therein as necessary. The elastic rubber belt 60 is formed in a seamless cylindrical shape, and the inner peripheral surface of the elastic rubber belt 60 forms a flat surface shape 62. A plurality of elastic protrusions 64 are provided on the outer peripheral surface of the elastic rubber belt 60. The elastic protrusion 64 may not be provided over the entire outer peripheral surface of the elastic rubber belt 60. For example, the elastic rubber belt 60 may be formed on a flat surface corresponding to the in-plane of the end plates 20a and 20b. The same applies to the following embodiments.

  The elastic protrusions 64 extend in the width direction (arrow B direction) of the elastic rubber belt 60 and are provided at predetermined intervals in the circumferential direction of the elastic rubber belt 60. As shown in FIG. 4, the elastic protrusion 64 has a thickness t2 equivalent to the thickness t1 of the elastic rubber belt 60 and is set to a height t3 larger than the thickness t1 (t1≈ t2 <t3). The interval t4 between the elastic protrusions 64 is set to be equal to the thickness t2 of the elastic protrusions 64 (t2≈t4).

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

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied from the oxidant gas inlet 52a of the end plate 20a to the oxidant gas supply communication hole 28a, and the fuel gas supply communication is made from the fuel gas inlet 56a. A fuel gas such as a hydrogen-containing gas is supplied to the holes 32a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied from the cooling medium inlet 54a to the cooling medium supply communication hole 30a.

  Therefore, as shown in FIG. 3, the oxidant gas is introduced from the oxidant gas supply communication hole 28a into the oxidant gas flow path 36 provided in the cathode-side separator 24. As a result, the oxidant gas is supplied to the cathode side electrode 48 constituting the electrolyte membrane / electrode structure 22 while moving in the direction of arrow B in the oxidant gas flow path 36.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 40 provided in the anode separator 26. The fuel gas introduced into the fuel gas flow path 40 is supplied to the anode side electrode 50 constituting the electrolyte membrane / electrode structure 22 while moving in the arrow B direction.

  Therefore, in the electrolyte membrane / electrode structure 22, the oxidant gas supplied to the cathode side electrode 48 and the fuel gas supplied to the anode side electrode 50 are consumed by an electrochemical reaction in the electrode catalyst layer, thereby generating power. Is done.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 48 is discharged to the oxidant gas discharge communication hole 28b and discharged to the outside of the fuel cell stack 10 via the oxidant gas outlet 52b (FIG. 1). reference).

  On the other hand, spent fuel gas supplied to and consumed by the anode-side electrode 50 is led out to the fuel gas discharge communication hole 32b and then discharged to the outside of the fuel cell stack 10 through the fuel gas outlet 56b ( (See FIG. 1).

  Further, as shown in FIG. 3, the cooling medium is introduced into the cooling medium flow path 38 from the cooling medium supply communication hole 30 a and then flows along the arrow B direction. The cooling medium is discharged to the cooling medium discharge communication hole 30b after the electrolyte membrane / electrode structure 22 is cooled. Further, as shown in FIG. 1, the cooling medium is discharged to the outside of the fuel cell stack 10 through the cooling medium outlet 54 b.

  In this case, in the first embodiment, the elastic rubber belt 60 is provided in order to apply a tightening load to the fuel cell stack 10 in the stacking direction, and the elastic rubber belt 60 is formed in a seamless cylindrical shape, and the stacked body. A flat surface shape 62 is formed on the inner peripheral surface on the 14th side. For this reason, it is possible to favorably disperse the surface pressure with respect to the laminated body 14, and to prevent a fastening failure due to concentration of the surface pressure.

  In addition, a plurality of elastic protrusions 64 are provided on the outer peripheral surface of the elastic rubber belt 60. Therefore, as shown in FIG. 4, when an external load F is applied to the fuel cell stack 10, the external load F is dispersed and absorbed by the elastic protrusions 64 falling down (elastic deformation) (FIG. 4). The external load F can be effectively relieved. Thereby, the laminated body 14 can maintain the desired fastening state, and can obtain an effect that the vibration resistance and the impact resistance can be improved.

  FIG. 5 is a schematic perspective explanatory view of a fuel cell stack 70 according to the second embodiment of the present invention. 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. Similarly, in the third and fourth embodiments described below, detailed description thereof is omitted.

  The fuel cell stack 70 includes an elastic rubber belt 72 instead of the elastic rubber belt 60. The elastic rubber belt 72 is configured in the same manner as the elastic rubber belt 60, and a plurality of elastic protrusions 74 are provided on the outer peripheral surface of the elastic rubber belt 72. The elastic protrusions 74 extend in the circumferential direction of the elastic rubber belt 72 and are provided at predetermined intervals in the width direction of the elastic rubber belt 72.

  In the second embodiment configured as described above, when an external load is applied to the fuel cell stack 70, the external load can be dispersed and absorbed under the action of the elastic deformation of the plurality of elastic protrusions 74. The same effects as those of the first embodiment can be obtained.

  FIG. 6 is a partially enlarged explanatory view of the elastic rubber belt 82 constituting the fuel cell stack 80 according to the third embodiment of the present invention.

  A plurality of elastic protrusions 84 are provided on the outer peripheral surface of the elastic rubber belt 82. The elastic protrusions 84 have a trapezoidal cross section, are extended in the width direction of the elastic rubber belt 82, and are provided at predetermined intervals in the circumferential direction of the elastic rubber belt 82. The elastic protrusions 84 may be provided so as to extend in the circumferential direction of the elastic rubber belt 82 and be separated by a predetermined interval in the width direction of the elastic rubber belt 82.

  In the third embodiment configured as described above, when the external load F is applied, the elastic protrusion 84 is elastically deformed so as to be crushed, whereby the external load F is dispersed and absorbed (in FIG. 6). , See dashed-two dotted line). For this reason, the effect similar to said 1st and 2nd embodiment is acquired, such as being able to relieve the external load F effectively.

  FIG. 7 is a partially enlarged explanatory view of the elastic rubber belt 92 constituting the fuel cell stack 90 according to the fourth embodiment of the present invention.

  A plurality of elastic protrusions 94 are provided on the outer peripheral surface of the elastic rubber belt 92. The elastic protrusions 94 have a cross-sectional wave shape, extend in the width direction of the elastic rubber belt 92, and are provided at predetermined intervals in the circumferential direction of the elastic rubber belt 92. The elastic protrusions 94 may be provided so as to extend in the circumferential direction of the elastic rubber belt 92 and be spaced apart by a predetermined interval in the width direction of the elastic rubber belt 92.

  In the fourth embodiment configured as described above, when the external load F is applied, the elastic protrusion 94 is elastically deformed so as to be crushed, whereby the external load F can be dispersed and absorbed. The same effects as those of the first to third embodiments can be obtained.

1 is a schematic perspective explanatory view of a fuel cell stack according to a first embodiment of the present invention. 2 is a cross-sectional side view of the fuel cell stack. FIG. It is a disassembled perspective explanatory drawing of the unit cell which comprises the said fuel cell stack. It is a partially expanded explanatory view of the elastic rubber belt which comprises the said fuel cell stack. FIG. 5 is a schematic perspective explanatory view of a fuel cell stack according to a second embodiment of the present invention. It is a partially expanded explanatory view of an elastic rubber belt constituting a fuel cell stack according to a third embodiment of the present invention. It is a partially expanded explanatory view of the elastic rubber belt which comprises the fuel cell stack which concerns on the 4th Embodiment of this invention. 2 is a perspective explanatory view of a fuel cell stack disclosed in Patent Document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 70, 80, 90 ... Fuel cell stack 12 ... Unit cell 14 ... Laminated body 16a, 16b ... Terminal plate 18a, 18b ... Insulating plate 20a, 20b ... End plate 22 ... Electrolyte membrane and electrode structure 24, 26 ... Separator 36 ... Oxidant gas flow path 38 ... Cooling medium flow path 40 ... Fuel gas flow path 46 ... Solid polymer electrolyte membrane 48 ... Cathode side electrode 50 ... Anode side electrodes 60, 72, 82, 92 ... Elastic rubber belt 62 ... Flat surface Shape 64, 74, 84, 94 ... elastic protrusion

Claims (3)

A unit cell having an electrolyte / electrode structure and a separator each having a pair of electrodes provided on both sides of the electrolyte is provided, and has a laminate in which a plurality of the unit cells are laminated, and ends at both ends in the lamination direction of the laminate. A fuel cell stack in which a plate is disposed,
Comprising an elastic rubber belt that orbits the outer circumference of the laminate and the end plate in the laminating direction and applies a tightening load between the end plates;
The elastic rubber belt is configured in a seamless cylindrical shape,
The fuel cell stack, wherein an inner peripheral surface of the elastic rubber belt has a flat surface shape and a plurality of elastic protrusions are provided on the outer peripheral surface of the elastic rubber belt.   2. The fuel cell stack according to claim 1, wherein the elastic protrusions extend in the width direction of the elastic rubber belt and are spaced apart from each other by a predetermined interval in the circumferential direction of the elastic rubber belt. Battery stack.   2. The fuel cell stack according to claim 1, wherein the elastic protrusions extend in a circumferential direction of the elastic rubber belt and are spaced apart from each other by a predetermined interval in the width direction of the elastic rubber belt. Battery stack.

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