JP6104833B2 - Fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell stack provided with a power generation cell having an electrolyte / electrode structure provided with electrodes on both sides of an electrolyte and a separator, and a laminate in which a plurality of the power generation cells are stacked.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure in which an anode electrode is disposed on one side of an electrolyte membrane made of a polymer ion exchange membrane and a cathode electrode is disposed on the other side of the electrolyte membrane ( MEA). The MEA is sandwiched between separators to constitute a power generation cell. This fuel cell is usually mounted on a fuel cell electric vehicle or the like as an in-vehicle fuel cell stack, for example, by stacking a predetermined number of power generation cells.

  Usually, a fuel cell stack is used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) of power generation cells are stacked in order to obtain a desired power generation. At that time, it is necessary to detect whether or not each power generation cell has a desired power generation performance. For this reason, the operation | work which detects the cell voltage for every electric power generation cell at the time of power generation is normally performed by connecting the cell voltage terminal provided in the separator to the voltage detection apparatus (cell voltage monitor).

  For example, in a fuel cell vehicle disclosed in Patent Document 1, a fuel cell stack is accommodated in a casing. The housing includes end plates disposed at both ends of the fuel cell stack in the stacking direction, and side plates extending in the stacking direction along the side surfaces of the fuel cell stack and fixed between the end plates. .

  The fuel cell vehicle is provided with a protective member that protects the cell voltage terminal, and the side plate is divided into a first side plate portion and a second side plate portion in order to expose the cell voltage terminal to the outside. On the other hand, the protective member is a flat plate that overlaps at least a part of the first side plate portion, as viewed from one side, at an end portion that passes between the divided first side plate portion and the second side plate portion and is exposed to the outside of the housing. Is provided.

  For this reason, when an external load is applied in the stacking direction of the fuel cell stack and the housing is deformed, at least the first side plate portion is held by the flat plate portion and is prevented from being deformed outward. Yes.

JP 2010-212157 A

  By the way, in said patent document 1, the side plate is divided | segmented into the 1st side plate part and the 2nd side plate part. For this reason, the strength of the entire side plate tends to decrease, and there is a risk of damage when a relatively large load is applied from the outside.

  The present invention solves this type of problem and suppresses as much as possible the reduction in the strength of the protective cover provided to cover the laminate, and the cable connected to the cell voltage terminal is well taken out to the outside. It is an object of the present invention to provide a fuel cell stack that can be used.

  The fuel cell stack according to the present invention includes a power generation cell having an electrolyte / electrode structure in which electrodes are provided on both sides of an electrolyte, and a separator. At least one separator constituting the power generation cell is provided with a cell voltage terminal, and includes a laminate in which a plurality of the power generation cells are stacked. End plates arranged at both ends in the stacking direction of the stacked body are fastened by a fastening bar to apply a load in the stacking direction to the stacked body, and a protective cover is disposed to cover the outer periphery of the stacked body.

Then, the center of the edge portion of the upper plate of the side middle portion or the lower plate constituting the protective cover, directly above the fastening bars arranged at the top of the stack, or of the fastening bars disposed below the stack A notch for allowing a cable connected to the cell voltage terminal to pass therethrough is formed immediately below .

  Further, in this fuel cell stack, it is preferable that a reinforcing rib portion is provided on the upper plate or the lower plate having a rectangular shape so as to connect diagonal positions.

  Further, in this fuel cell stack, the fuel cell stack is mounted on the fuel cell vehicle, and the stacked body is configured such that the power generation cells are stacked in the vehicle width direction, and the notch is in the vehicle width direction of the upper plate or the lower plate. It is preferable to be provided at the center of the side of one end.

  According to this invention, the notch part is formed in the side center part of the upper board, or the side center part of the lower board corresponding to the fastening bar arrange | positioned at the upper part or lower part of a laminated body. For this reason, since an external load uses a fastening bar or an end plate as a load path, the upper plate or the lower plate can satisfactorily suppress a decrease in strength due to the notch.

  Therefore, it is possible to suppress the strength reduction of the protective cover provided to cover the laminated body as much as possible, and the cable connected to the cell voltage terminal can be taken out well through the notch. Become.

1 is a schematic plan view of a fuel cell electric vehicle equipped with a fuel cell stack according to a first embodiment of the present invention. It is a schematic perspective view of the fuel cell stack. It is a partially exploded perspective view of the fuel cell stack. It is a principal part disassembled perspective explanatory drawing of the electric power generation cell which comprises the said fuel cell stack. FIG. 5 is a partially exploded perspective view of a fuel cell stack according to a second embodiment of the present invention.

  As shown in FIG. 1, the fuel cell stack 10 according to the first embodiment of the present invention is accommodated in a front box (so-called motor room) 12f of a fuel cell electric vehicle (fuel cell vehicle) 12, for example.

  As shown in FIGS. 1 to 3, the fuel cell stack 10 includes a power generation cell 14 and a protective cover 16 that houses a stacked body 14 a in which the plurality of power generation cells 14 are stacked. In addition, the accommodation place of the fuel cell stack 10 is not limited to the front box 12f, and may be, for example, the vehicle center part under the floor or the vicinity of the rear trunk.

  As shown in FIG. 3, the power generation cells 14 are stacked in the vehicle width direction (arrow B direction) intersecting the vehicle length direction (vehicle front-rear direction) (arrow A direction) of the fuel cell electric vehicle 12 in the standing position. . At one end of the power generation cell 14 in the stacking direction, a first terminal plate 20a, a first insulating plate 22a, and a first end plate 24a are sequentially arranged outward. At the other end of the power generation cell 14 in the stacking direction, a second terminal plate 20b, a second insulating plate 22b, and a second end plate 24b are sequentially arranged outward.

  A first power output terminal 26a connected to the first terminal plate 20a extends outward from a substantially central portion (which may be eccentric from the central portion) of the horizontally long first end plate 24a. A second power output terminal 26b connected to the second terminal plate 20b extends outward from a substantially central portion of the horizontally long (rectangular) second end plate 24b. For example, a load such as a vehicle driving motor (not shown) is connected to the first power output terminal 26a and the second power output terminal 26b.

  Between each side of the first end plate 24a and the second end plate 24b, a fastening bar 28 having a certain length corresponding to the center position of each side is arranged. Both ends of the fastening bar 28 are fixed by screws 30 and apply a tightening load in the stacking direction (arrow B direction) to the plurality of stacked power generation cells 14.

  As shown in FIG. 4, the power generation cell 14 includes an electrolyte membrane / electrode structure 32, and a cathode separator 34 and an anode separator 36 that sandwich the electrolyte membrane / electrode structure 32.

  The cathode-side separator 34 and the anode-side separator 36 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal plate that has been subjected to a corrosion-proof surface treatment. The cathode-side separator 34 and the anode-side separator 36 have a rectangular planar shape, and are formed into a concavo-convex shape by pressing a metal thin plate into a wave shape. For example, a carbon separator may be used for the cathode side separator 34 and the anode side separator 36 instead of the metal separator.

  The cathode side separator 34 and the anode side separator 36 have a horizontally long shape, the long side extends in the horizontal direction (arrow A direction), and the short side extends in the gravity direction (arrow C direction). In addition, you may arrange | position so that a short side may extend in a horizontal direction and a long side may extend in a gravitational direction.

  An oxidant gas supply communication hole 38a and a fuel gas supply communication hole 40a are provided at one end edge in the long side direction (arrow A direction) of the power generation cell 14 so as to communicate with each other in the arrow B direction. The oxidant gas supply communication hole 38a supplies an oxidant gas, for example, an oxygen-containing gas, while the fuel gas supply communication hole 40a supplies a fuel gas, for example, a hydrogen-containing gas.

  The other end edge in the long side direction of the power generation cell 14 communicates with each other in the arrow B direction, and a fuel gas discharge communication hole 40b for discharging the fuel gas, and an oxidant gas for discharging the oxidant gas. A discharge communication hole 38b is provided.

  Two cooling media communicate with each other in the direction of arrow B on one side (oxidant gas supply communication hole 38a and fuel gas supply communication hole 40a side) of both ends in the short side direction (arrow C direction) of the power generation cell 14. Supply communication holes 42a are provided on opposite sides. Two cooling medium discharge communication holes 42b are connected to each other in the direction of arrow B on the other side (the fuel gas discharge communication hole 40b and the oxidant gas discharge communication hole 38b side) of both ends in the short side direction of the power generation cell 14. , Provided on opposite sides. The cooling medium supply communication hole 42a supplies the cooling medium, while the cooling medium discharge communication hole 42b discharges the cooling medium.

  The electrolyte membrane / electrode structure 32 includes, for example, a solid polymer electrolyte membrane 44 in which a perfluorosulfonic acid thin film is impregnated with water, and a cathode electrode 46 and an anode electrode 48 that sandwich the solid polymer electrolyte membrane 44. Prepare.

  The cathode electrode 46 and the anode electrode 48 are formed by uniformly applying 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 to the surface of the gas diffusion layer. And an electrode catalyst layer (not shown) to be formed. The electrode catalyst layer is formed on both surfaces of the solid polymer electrolyte membrane 44, for example.

  An oxidant gas flow path 50 that connects the oxidant gas supply communication hole 38a and the oxidant gas discharge communication hole 38b is formed on the surface 34a of the cathode separator 34 facing the electrolyte membrane / electrode structure 32. The oxidant gas channel 50 is formed by a plurality of wavy channel grooves (or straight channel grooves) extending in the direction of arrow A.

  A fuel gas flow path 52 that connects the fuel gas supply communication hole 40a and the fuel gas discharge communication hole 40b is formed on the surface 36a of the anode separator 36 facing the electrolyte membrane / electrode structure 32. The fuel gas channel 52 is formed by a plurality of wave-like channel grooves (or straight channel grooves) extending in the direction of arrow A.

  Between the surface 36b of the anode side separator 36 and the surface 34b of the adjacent cathode side separator 34, there is a cooling medium flow channel 54 communicating with the cooling medium supply communication holes 42a, 42a and the cooling medium discharge communication holes 42b, 42b. It is formed. The cooling medium flow channel 54 circulates the cooling medium over the electrode range of the electrolyte membrane / electrode structure 32.

  A first seal member 56 a is integrally formed on the surfaces 34 a and 34 b of the cathode side separator 34 around the outer peripheral edge of the cathode side separator 34. A second seal member 56b is integrally formed on the surfaces 36a and 36b of the anode side separator 36 around the outer peripheral edge of the anode side separator 36.

  As the first seal member 56a and the second seal member 56b, for example, EPDM, NBR, fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber or the like, cushion material Alternatively, an elastic seal member such as a packing material is used.

  On the upper side of the power generation cell 14, for example, a recess 58 is formed at a position shifted toward the cooling medium discharge communication hole 42b. The anode side separator 36 (or the cathode side separator 34) constituting the power generation cell 14 is provided with a cell voltage terminal 58a which is disposed in the recess 58 and used when detecting the cell voltage.

  A connector (protective member) 60 is attached for each predetermined number of cell voltage terminals 58a. A cable (harness) 60a connected to the connector 60 is drawn out of the fuel cell stack 10 and connected to a control unit (cell voltage ECU) (not shown).

  As shown in FIGS. 2 and 3, the first end plate 24a includes an oxidant gas supply manifold 61a and an oxidant gas discharge manifold 61b communicating with the oxidant gas supply communication hole 38a and the oxidant gas discharge communication hole 38b. And are attached. A fuel gas supply manifold 62a and a fuel gas discharge manifold 62b communicating with the fuel gas supply communication hole 40a and the fuel gas discharge communication hole 40b are attached to the first end plate 24a.

  As shown in FIG. 1, a cooling medium supply manifold 64a and a cooling medium discharge manifold 64b communicating with the pair of cooling medium supply communication holes 42a and the pair of cooling medium discharge communication holes 42b are attached to the second end plate 24b.

  As shown in FIG. 3, the protective cover 16 includes a first end plate 24a and a second end plate 24b at two sides (surfaces) at both ends in the vehicle width direction (arrow B direction). Two sides (surfaces) at both ends in the vehicle length direction (arrow A direction) of the protective cover 16 are constituted by a front side panel (front plate) 66 and a rear side panel (rear plate) 68. Two sides (surfaces) at both ends of the protective cover 16 in the vehicle height direction (arrow C direction) are constituted by an upper side panel (upper plate) 70 and a lower side panel (lower plate) 72.

  The front side panel 66 and the rear side panel 68 are formed by, for example, extrusion molding, casting, machining, or the like. The front side panel 66 has a horizontally long plate shape arranged in the vertical direction, and has inner bulging portions 66 a and 66 b that bulge inward of the protective cover 16. The inner bulging portions 66 a and 66 b have a function of transmitting a load from the outside (a load from the front) to the upper side panel 70 and the lower side panel 72. The upper side panel 70 and the lower side panel 72 have a function of protecting the fuel cell stack 10 against loads from above and below.

  The rear side panel 68 has a horizontally long plate shape arranged in the vertical direction, and has inner bulging portions 68 a and 68 b that bulge inwardly of the protective cover 16. In addition, you may comprise the front side panel 66 and the back side panel 68 by a flat plate member arrange | positioned between a pair of press plates similarly to the upper side panel 70 mentioned later.

  The upper side panel 70 includes an outer plate 74 and an inner plate 76 that are a pair of press plates (press-molded plates) joined to each other. The outer plate 74 and the inner plate 76 are formed of metal thin plates whose surfaces are press-molded in an uneven shape. Between the outer plate 74 and the inner plate 76, prismatic members 78a and 78b are interposed corresponding to both ends (both ends in the arrow A direction) of the plate extending in the stacking direction (arrow B direction).

  The outer plate 74 constitutes the upper surface of the protective cover 16 and has a thin plate shape. On the surface of the outer plate 74, reinforcing rib portions 80a and 80b are provided with the diagonal position interposed therebetween (or connecting the diagonal position and the opposite side position). The surface positions of the rib portions 80a and 80b are different from the other surface positions of the outer plate 74 in the thickness direction, that is, set to a position that is higher in the height direction (position that bulges upward).

  The inner plate 76 forms an inner peripheral surface of the protective cover 16 and has a thin plate shape, and has a curved shape, a bent shape, or both shapes along the outer peripheral shape of the power generation cell 14. The outer plate 74 and the inner plate 76 are fixed by MIG welding, TIG welding, or the like.

  The upper side panel 70 corresponds to the upper side fastening bar 28 at the side central portion on the first end plate 24a side (one end side in the vehicle width direction), that is, vertically above the fastening bar 28, A notch 82 is formed. The notch 82 is formed by integrally cutting the outer plate 74 and the inner plate 76, and preferably has an opening shape larger than the width dimension of the fastening bar 28. In addition, the notch part 82 may have an R shape at the corner, or may be configured by a rectangular opening whose four sides are closed.

  The notch portion 82 is provided at a position that avoids the rib portions 80a and 80b. This is to prevent the strength of the rib portions 80a and 80b itself from being lowered. Cables 60a connected to the connectors 60 pass through the notches 82, the cables 60a are taken out of the protective cover 16, and connected to a control unit (cell voltage ECU) (not shown). In FIG. 1 to FIG. 3, one cable 60 a is shown, but actually, a plurality of the cables 60 a are taken out from the notch portion 82.

  The lower side panel 72 includes an outer plate 84 and an inner plate 86 which are a pair of press plates (plate forming plates) joined to each other. The outer plate 84 and the inner plate 86 are composed of thin metal plates whose surfaces are press-formed in an uneven shape. Between the outer plate 84 and the inner plate 86, prismatic members 88a and 88b are interposed corresponding to both end portions (both end portions in the arrow A direction) of the plate extending in the stacking direction (arrow B direction).

  The outer plate 84 forms the lower surface of the protective cover 16 and has a thin plate shape. On the surface of the outer plate 84, reinforcing rib portions (not shown) are provided connecting diagonal positions (or connecting diagonal positions and opposite side positions). The inner plate 86 forms an inner peripheral surface of the protective cover 16 and has a thin plate shape, and has a curved shape, a bent shape, or both shapes along the outer peripheral shape of the power generation cell 14.

  The front side panel 66, the rear side panel 68, the upper side panel 70, and the lower side panel 72 are each formed with a hole 90 for inserting a bolt. When the bolts 92 inserted into the holes 90 are screwed into the screw holes 94, the components of the protective cover 16 are fixed to each other and to the first end plate 24a and the second end plate 24b. The

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

  First, as shown in FIG. 2, an oxidizing gas such as an oxygen-containing gas is supplied from the oxidizing gas supply manifold 61a of the first end plate 24a to the oxidizing gas supply communication hole 38a. A fuel gas such as a hydrogen-containing gas is supplied from the fuel gas supply manifold 62a of the first end plate 24a to the fuel gas supply communication hole 40a. Further, as shown in FIG. 1, in the second end plate 24b, a cooling medium such as pure water, ethylene glycol, or oil is supplied from the cooling medium supply manifold 64a to the pair of cooling medium supply communication holes 42a.

  Therefore, as shown in FIG. 4, the oxidant gas is introduced into the oxidant gas flow path 50 of the cathode-side separator 34 from the oxidant gas supply communication hole 38a. The oxidant gas moves in the direction of arrow A along the oxidant gas flow path 50 and is supplied to the cathode electrode 46 of the electrolyte membrane / electrode structure 32.

  On the other hand, the fuel gas is supplied to the fuel gas flow path 52 of the anode separator 36 from the fuel gas supply communication hole 40a. The fuel gas moves in the direction of arrow A along the fuel gas passage 52 and is supplied to the anode electrode 48 of the electrolyte membrane / electrode structure 32.

  Therefore, in the electrolyte membrane / electrode structure 32, the oxidizing gas supplied to the cathode electrode 46 and the fuel gas supplied to the anode electrode 48 are consumed by an electrochemical reaction in the electrode catalyst layer to generate power. Is called.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 46 of the electrolyte membrane / electrode structure 32 is discharged in the direction of arrow B along the oxidant gas discharge communication hole 38b. On the other hand, the fuel gas supplied to and consumed by the anode electrode 48 of the electrolyte membrane / electrode structure 32 is discharged in the direction of arrow B along the fuel gas discharge communication hole 40b.

  The cooling medium supplied to the pair of cooling medium supply communication holes 42 a is introduced into the cooling medium flow path 54 between the cathode side separator 34 and the anode side separator 36. The cooling medium once flows in the direction of arrow C and then moves in the direction of arrow A to cool the electrolyte membrane / electrode structure 32. The cooling medium moves outward in the direction of arrow C, and is then discharged in the direction of arrow B along the pair of cooling medium discharge communication holes 42b.

  In this case, in the first embodiment, as shown in FIGS. 2 and 3, the fastening bar 28 disposed on the upper side of the stacked body 14 a is provided at the central portion of the upper side panel 70 on the first end plate 24 a side. Correspondingly, a notch 82 is formed. Cables 60 a connected to the connectors 60 pass through the notches 82, and the cables 60 a are taken out of the protective cover 16.

  Here, as shown in FIG. 1, when the external load F1 is applied to the fuel cell electric vehicle 12 from the vehicle width direction (arrow B direction), the external load F1 uses the fastening bar 28 as a load path. Yes. For this reason, even if the upper side panel 70 forms the notch part 82, a strength fall is suppressed favorably.

  Further, when the external load F2 is applied to the fuel cell electric vehicle 12 from the front in the vehicle length direction to the rear (arrow Ab direction), the external load F2 uses the first end plate 24a and the second end plate 24b as load paths. I use it. Therefore, even if the upper side panel 70 forms the notch part 82, the strength reduction is satisfactorily suppressed.

  As a result, the strength of the protective cover 16 provided to cover the laminate 14a is suppressed as much as possible, and the cable 60a connected to the cell voltage terminal 58a can be taken out to the outside. can get.

  FIG. 5 is a partially exploded perspective view of the fuel cell stack 100 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.

  The protective cover 102 constituting the fuel cell stack 100 includes a front side panel 66, a rear side panel 68, an upper side panel (upper plate) 104, and a lower side panel (lower plate) 106. In the second embodiment, the upper side panel 104 is not provided with a notch, and the lower side panel 106 is provided with a notch 108.

  The lower side panel 106 forms a notch 108 at the center of the side on the second end plate 24b side, corresponding to the lower fastening bar 28, that is, vertically below the fastening bar 28. . The cutout 108 is formed by integrally cutting the outer plate 84 and the inner plate 86, and preferably has an opening shape larger than the width dimension of the fastening bar 28.

  The cutout portion 108 is provided at a position that avoids a rib portion (not shown). A cable 60a connected to the connector 60 passes through the notch 108, and the cable 60a is taken out of the protective cover 16 and connected to a control unit (cell voltage ECU) (not shown).

  In this case, in the second embodiment, a cutout portion 108 is formed at the center of the side of the lower side panel 106 on the second end plate 24b side corresponding to the fastening bar 28 disposed at the lower portion of the stacked body 14a. Has been. A cable 60 a connected to the connector 60 passes through the notch 108, and the cable 60 a is taken out of the protective cover 102.

  For this reason, while suppressing the strength fall of the protective cover 102 provided covering the laminated body 14a as much as possible, the cable 60a connected to the cell voltage terminal 58a can be satisfactorily taken out to the outside, etc. The same effects as those of the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 10,100 ... Fuel cell stack 12 ... Fuel cell electric vehicle 12f ... Front box 14 ... Power generation cell 16, 102 ... Protective cover 24a, 24b ... End plate 28 ... Fastening bar 32 ... Electrolyte membrane electrode assembly 34 ... Cathode side separator 36 ... anode side separator 38a ... oxidant gas supply communication hole 38b ... oxidant gas discharge communication hole 40a ... fuel gas supply communication hole 40b ... fuel gas discharge communication hole 42a ... cooling medium supply communication hole 42b ... cooling medium discharge communication hole 44 ... Solid polymer electrolyte membrane 46 ... Cathode electrode 48 ... Anode electrode 50 ... Oxidant gas channel 52 ... Fuel gas channel 54 ... Cooling medium channel 58a ... Cell voltage terminal 60 ... Connector 60a ... Cable 66 ... Front side panel 68 ... rear side panels 70, 104 ... upper side panels 72, 106 ... lower Side panel 74, 84 ... outer plate 76, 86 ... inner plate 80a, 80b ... ribs 82,108 ... cut-out portion

Claims (3)

A power generation cell having an electrolyte / electrode structure provided with electrodes on both sides of the electrolyte and a separator is provided, and at least one separator constituting the power generation cell is provided with a cell voltage terminal, and a plurality of the power generation cells End plates disposed on both ends of the laminate in the stacking direction are provided with a stack in which cells are stacked, and are fastened by fastening bars to apply a load in the stacking direction to the stack, and the outer periphery of the stack is A fuel cell stack that covers and is provided with a protective cover,
Wherein the side central portion of the upper plate of the side middle portion or the lower plate constituting the protective cover, directly above the engagement bar disposed over portions of the laminate, or the disposed under the stack A fuel cell stack , wherein a notch for allowing a cable connected to the cell voltage terminal to pass therethrough is formed immediately below the fastening bar .   2. The fuel cell stack according to claim 1, wherein the upper plate or the lower plate having a rectangular shape is provided with reinforcing rib portions connecting diagonal positions. 3. The fuel cell stack according to claim 1 or 2, wherein the fuel cell stack is mounted on a fuel cell vehicle,
The fuel cell stack, wherein the stack includes the power generation cells stacked in a vehicle width direction, and the cutout portion is provided at a central portion of the side of one end of the upper plate or the lower plate in the vehicle width direction. .

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