JP2002367663A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To structure a small size and light weight fuel cell stack. SOLUTION: A laminated body 14 laminated with unit cells 12 is housed in a case 20 together with current collector electrodes 16a, 16b, insulating plates 58a, 58b and an end plate 18. Cone disc springs 22 are provided between the end plate 18 and the case 20, and the laminated body 14 is pressure supported by elastically energizing (pressing on) the end plate 18 by the cone disc springs 22. Further, the end plate 18 is supported to the case 20 by engaging the protrusion member 68 jointed to the case 20 in free sliding with a side groove 64 provided at the both ends of the end plate 18, thereby, the end plate 18 is displaced as it is guided by the protrusion member 68 when the cone disc springs 22 are compressed or expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel cell stack, and more particularly, to a small and lightweight fuel cell stack.

[0002]

2. Description of the Related Art In a general fuel cell stack, a laminate composed of a predetermined number of unit cells electrically connected in series to each other and laminated is interposed between a set of end plates. 1 placed outside the set of end plates
The backup plates of the set are configured to be tightened by a tightening member such as a tie rod. Due to this tightening, the laminate and the set of end plates are held under pressure. A disc spring, a bladder, and the like are usually interposed between one end plate and the backup plate.

[0003] The unit cell includes a joint formed by interposing an electrolyte layer between an anode electrode and a cathode electrode, and a pair of separators sandwiching the joint. The surface of both separators facing the anode electrode has a fuel gas (for example,
A first gas flow path for supplying / discharging a hydrogen-containing gas containing hydrogen as a main component is provided. On the other hand, an oxidizing gas is supplied to the cathode-side electrode on a surface facing the cathode-side electrode. A second gas flow path for supplying and discharging (for example, an oxygen-containing gas containing oxygen) is provided.

When operating the fuel cell stack configured as described above, hydrogen in the hydrogen-containing gas supplied to the anode is ionized on the electrode catalyst layer constituting the anode, and as a result, hydrogen Ions and electrons are generated. Of these, hydrogen ions move to the cathode side through the electrolyte membrane. During this time, the electrons are taken out to an external circuit and used as DC electric energy before reaching the cathode side electrode.

Here, an oxygen-containing gas such as air is supplied to the cathode side electrode. Therefore, at the cathode-side electrode, the hydrogen ions, the electrons, and oxygen in the oxygen-containing gas react, and as a result, water is generated.

[0006] This type of fuel cell stack is mounted on the body of a vehicle such as an automobile. In this case, the electric energy generated by the above-mentioned electrochemical reaction drives the motor to convert the chemical energy into mechanical energy, and thereby the vehicle runs. As described above, a vehicle that runs using a fuel cell stack as a drive source, a so-called fuel cell vehicle, has a remarkable emission of CO _{2 that} causes global warming, NO _X or SO _X that causes pollution, and hydrocarbon gas. Because of its small number, it is attracting attention as one that can greatly contribute to environmental protection.

When a fuel cell stack is mounted on a vehicle body,
For example, mounting brackets are respectively fixed to both backup plates or a backup plate at one end and an end plate at the other end, and both mounting brackets are connected to the vehicle body. That is, the fuel cell stack
It is mounted on the vehicle body via a mounting bracket.

Here, one of the mounting brackets is firmly connected to the vehicle body by, for example, a bolt passed through a bolt hole. Further, the other mounting bracket is provided with, for example, an oval groove having a step portion,
The bolt passing through the oblong groove presses the bottom surface of the step portion with an appropriate force with its head, and is slidably connected to the vehicle body.

When a fuel cell vehicle is run, a load acts on the fuel cell stack due to vibrations during running, repetition of starting and stopping, and the like. Due to this load, or when the fuel cell stack undergoes thermal expansion and contraction when the temperature of the fuel cell stack is raised and lowered to operate and stop the fuel cell stack, the fuel cell stack is
It expands and contracts along the stacking direction of the stack. In other words, the fuel cell stack undergoes a dimensional change along the stacking direction.

Further, the electrolyte layer swells and shrinks in the stacking direction of the stacked body following the absorption and release of the water generated by the electrochemical change. In addition, the electrolyte layer undergoes a so-called sag, in which dimensions are slightly reduced due to repeated temperature changes accompanying the operation / stop of the fuel cell stack. This set occurs similarly in a seal member holding the joined body, a separator, and the like. In the fuel cell stack, even when such a dimensional change occurs in the electrolyte layer, the sealing member, the separator, and the like, the dimensional change occurs in the stacking direction.

At this time, the disc spring, the bladder and the like are extended. As described above, the disc spring or the bladder contracts or expands in accordance with the thermal expansion or contraction of the laminate, whereby the pressure holding force on the laminate is maintained substantially uniformly. In other words, the pressure holding of the stacked body is favorably maintained, so that the electrical contact between the unit cells is maintained.

When the disc spring or the bladder contracts or expands, one of the mounting brackets slides with respect to the vehicle body.

[0013]

As described above, when the fuel cell stack is mounted on the vehicle body, one of the mounting brackets is slidably connected to the vehicle body, but this is firmly positioned and fixed. It is not possible. That is,
When both mounting brackets are firmly positioned and fixed, for example, thermal expansion of the laminate is significantly suppressed, and as a result, a large thermal stress acts on the fuel cell stack. .

The mounting bracket slidably connected in this manner cannot sufficiently receive the load applied to the fuel cell stack due to the vibration or impact generated when the vehicle is running. Therefore, a large mounting bracket is used as the mounting bracket that is rigidly connected to the vehicle so that it can sufficiently receive a load due to vibration or impact.

However, for this reason, the space for mounting the fuel cell stack is vast. Moreover,
Since the weight of the mounting bracket increases, the weight of the fuel cell stack inevitably also increases. Therefore, a large driving force is required when the vehicle body on which the fuel cell stack is mounted is run.

When the fuel cell stack is mounted on a vehicle body via a mounting bracket fixed to both backup plates, a vertical load of the end plates is applied between the backup plates and the end plates. , For example, a guide pin or the like is required.

On the other hand, when the fuel cell stack is mounted on the vehicle body via the mounting bracket fixed to the backup plate at one end and the end plate at the other end, the mounting bracket fixed to the end plate does not interfere with the backup plate. In such a case, the layout may be difficult.

By the way, Japanese Patent Application Laid-Open No. 7-249426 proposes a structure in which a stacked body is housed in a case and a stud bolt for holding the stacked body under pressure is unnecessary. However, in this case, since one set of end plates is not held, the stack undergoes thermal expansion and contraction along the stacking direction and changes dimensions as the fuel cell stack starts and stops, and the vehicle body vibrates. By doing so, the end plate may be displaced. When such a situation occurs, the pressure holding force on the laminate decreases, and it becomes difficult to maintain electrical contact between the unit cells constituting the laminate.

Apart from this, there is known a structure in which the laminate is housed in a case, a pressure chamber is formed inside the case, and a reaction gas is supplied to pressurize the laminate (JP-A-7-335243). Reference). However, in this case, the case needs to be manufactured with high dimensional accuracy in order to make the case act like a cylinder. For this reason, there is a problem that the manufacturing cost of the case, and eventually the fuel cell stack, rises.

The present invention has been made in order to solve the above-mentioned problems, and the layout becomes easy by eliminating the need for a backup plate, and the pressure holding force for the laminate can be maintained. An object of the present invention is to provide a fuel cell stack that is reduced in size and weight.

[0021]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a joined body in which an electrolyte is interposed between an anode electrode and a cathode electrode, and a method for sandwiching the joined body. In a fuel cell stack including a stacked body in which a plurality of unit cells each having a set of separators are stacked, an end plate that presses and holds the stacked body from an end of the stacked body, and houses the stacked body and the end plate. And a pressing member that presses the end plate toward the laminate is provided between the end plate and the case, and the end plate has a concave portion or a convex portion. The case is provided with a convex portion or a concave portion which is slidably engaged with the concave portion or the convex portion.

That is, in the present invention, the laminate accommodated in the case is pressed and held by being pressed by the pressing member. With such a configuration, a tightening member such as a tie rod is not required. Therefore, a backup plate that requires a hole forming margin for providing a through hole through which the tie rod passes is used to reduce the outer size of the fuel cell stack. It can be significantly smaller than a fuel cell. In other words, the size of the fuel cell stack can be reduced. Moreover, there is no need to use a backup plate as in the related art. Therefore, the weight can be reduced.

Further, since one set of end plates is also housed in the case and is held under pressure under the action of the pressing member, the size of the fuel cell stack due to thermal expansion and contraction during operation / stop is increased. Even when a change occurs, or when a load acts on the fuel cell stack due to vibration or the like while the vehicle on which the fuel cell stack is mounted is running, electrical contact between the unit cells is reliably maintained.

Further, as the case, a case having not high dimensional accuracy can be used. Therefore, the production cost of the fuel cell stack does not rise.

In this fuel cell stack, since the concave portion or the convex portion provided on the end plate is slidably engaged with the convex portion or the concave portion provided on the case, the end plate may be skewed. And can be displaced along the stacking direction of the stack. For this reason, the pressure acting on the one end surface in the one end surface of the laminate becomes substantially equal. That is, it is possible to avoid the occurrence of a portion that is gently pressurized as compared with other portions, so that it is possible to avoid the occurrence of a contact failure between the unit cells. It is possible to prevent the power generation characteristics of the fuel cell stack from deteriorating due to an increase in resistance.

In addition, since the end plate is supported by the case by the engagement between the concave portion and the convex portion, the end plate can be prevented from being detached from the fuel cell stack. That is, the end plate is prevented from coming off by the engagement between the concave portion and the convex portion.

Such a fuel cell stack can be mounted on a vehicle body. That is, the fuel cell stack according to the present invention can be suitably used for a vehicle. Here, the vehicle only needs to run using the electromotive force of the fuel cell stack as a drive source, and is not particularly limited to a general private vehicle.

In this case, the case may be provided with a mounting boss for passing a connecting member for connecting the fuel cell stack and the vehicle body. As will be appreciated from this, the fuel cell stack according to the present invention can be mounted on a vehicle without providing a mounting bracket. For this reason, the size and weight of the fuel cell stack can be further reduced.

Further, in this case, the case can be firmly connected to the vehicle. That is, there is no need to connect the case so as to be slidable with respect to the vehicle. For this reason, it is not necessary to increase the size of the mounting boss portion of the case, so that it is possible to prevent the mounting space of the fuel cell stack from being enlarged.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a fuel cell stack according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic overall perspective view of the fuel cell stack according to the present embodiment, and FIG. 2 is a schematic plan view cutaway. The fuel cell stack 10 includes a stack 14 in which a predetermined number of unit cells 12 are electrically connected to each other in series and stacked in the direction of arrow A;
4, a pair of current collecting electrodes 16a and 16b, an end plate 18 disposed outside the current collecting electrode 16a, a stacked body 14, the current collecting electrodes 16a and 1b,
6b and a case 20 for housing the end plate 18. Further, between the end plate 18 and one end surface of the case 20, a plurality of disc springs 2 as pressing members are provided.
2 are interposed.

First, the configuration of the unit cell 12 will be briefly described.

As shown in FIG. 3, which is an enlarged cross-sectional view of a main part of the laminated body 14, the unit cell 12 includes an anode 30
And a cathode 36 on which an electrolyte layer 34 is interposed. As the electrolyte layer 34, a hydrogen ion conductor such as a perfluorosulfonic acid thin film impregnated with water is selected.

The anode 30 and the cathode 32 have a gas diffusion layer (not shown) made of carbon cloth and the like, and a porous carbon particle having a platinum alloy supported on the surface thereof is formed on the surface of the gas diffusion layer. And an electrode catalyst layer (not shown) laminated in a similar manner, and the electrode catalyst layers are opposed to each other with the electrolyte layer 34 interposed therebetween.
Is joined to. The electrolyte layer 34 is housed and held in the opening of the frame-shaped seal member 38, while the cathode electrode 32 or the anode 30 is housed and held in the openings of the gaskets 40a and 40b. The unit cell 12 is formed by sandwiching the gaskets 40a and 40b and the frame-shaped seal member 38 holding the joined body 36 between a pair of separators 42a and 42b.

A first gas flow path 44 for supplying / discharging a hydrogen-containing gas to / from the anode 30 is provided on the surface of each of the separators 42a and 42b facing the anode 30. Similarly, the cathode-side electrode 3
A second gas flow path 46 for supplying / discharging an oxygen-containing gas to / from the cathode-side electrode 32 is provided on a surface facing the second electrode 2.

As shown in FIG. 4, which is a schematic overall perspective view of the unit cell 12, the separators 42a and 42b, the gaskets 40a and 40b, and the frame-shaped seal member 38 are provided at the upper right corner (the end plate 18 side). A first gas inlet passage 48 for passing the hydrogen-containing gas is provided in the upper left corner (when the front is the front), and an unreacted hydrogen-containing gas is provided at a diagonal position thereof. First
A gas outlet passage 50 is provided. Similarly, a second gas inlet passage 52 for allowing the oxygen-containing gas to pass therethrough is provided at the upper left corner (upper right corner when the end plate 18 side is the front), and at a diagonal position thereof. Is a second gas outlet passage 5 for passing unreacted oxygen-containing gas.
4 are provided. Of course, both the first gas inlet passage 48 and the first gas outlet passage 50 communicate with the first gas passage 44, while the second gas inlet passage 52 and the second gas
Each of the gas outlet passages 54 communicates with the second gas passage 46.

Separators 42a, 42b, gasket 4
0a, 40b and the frame-shaped seal member 38, further between the first gas inlet passage 48 and the second gas outlet passage 54, and between the second gas inlet passage 52 and the first gas outlet passage 50. , Cooling water passages 56a, 56b are provided, respectively.

The laminate 14 includes a predetermined number of the unit cells 12.
Are electrically connected in series to each other and stacked (see FIG. 1). Of these, the unit cells 12, 12 located at both ends have current collecting electrodes 16a, 16b.
Are electrically connected. End plate 18
Are arranged outside the current collecting electrode 16a via an insulating plate 58a for preventing electric leakage.

A plurality of spindles 60 are joined to the end face of the end plate 18 facing the case 20 (see FIGS. 1 and 2).
Is held in. Further, as shown in FIGS. 1 and 5, lateral grooves 64, 64 as concave portions are provided at left and right ends of the end plate 18, respectively.

The case 20 is made of a metal bottomed frame. An insulating plate 58b is interposed between the case 20 and the current collecting electrode 16b to prevent electric leakage (see FIG. 1). The insulating plate 58b also has a first gas inlet passage 48, a first gas outlet passage 50, a second gas inlet passage 52, a second gas outlet passage 54, and a cooling water passage 56.
a and 56b are provided.

The end plate 18 of the case 20
At the end face facing the
Is provided. By inserting the support shaft 60 into the insertion hole 66 and seating the disc spring 22 at the end on the bottom surface of the annular recess 67 provided on the inner surface of the case 20, the disc spring 2
2 is compressed and the case 20 and the end plate 1
8 interposed. For this reason, the end plate 18
Is constantly resiliently biased toward the laminate 14 by the disc spring 22, and as a result, the laminate 14 is pressed and held by the end plate 18. In other words, the laminate 14 is pressed and held by the end plate 18.

A lateral groove 64 provided on the end plate 18 is provided on the side surface of the case 20 (see FIGS. 1 and 5).
The projection member 68 whose size is slightly smaller than the width of the lateral groove 64 is joined to a portion corresponding to. That is, the projecting member 68 is slidably engaged with the lateral groove 64 of the end plate 18, and the end plate 18 is supported by the case 20 by this engagement.

Further, an end face of the case 20 facing the insulating plate 58b is provided with a first gas inlet passage 4.
8, a first gas outlet passage 50, a second gas inlet passage 52, a second gas outlet passage 54, and cooling water passages 56a and 56b. At each corner of the outer surface of the case 20, a mounting boss 74 provided with a through hole 72 for passing a bolt (connection member) (not shown) for connecting the case 20 to an automobile body is joined. I have.

In the fuel cell stack 10 configured as described above, a hydrogen-containing gas supply source and an oxygen-containing gas supply source (both not shown) are provided in the first and second gas inlet passages 48 and 52 of the case 20. Are connected to each other, and the first
A gas recovery mechanism (not shown) is connected to the second gas outlet passages 50 and 54, respectively. Further, a cooling water supply source (not shown) is connected to the cooling water passage 56a of the case 20, while a cooling water recovery mechanism (not shown) is connected to the cooling water passage 56b.

As described above, in the present embodiment, the laminate 1
Since 4 is accommodated in the case 20 and is held under pressure by the disc spring 22 (pressing member), it is not necessary to use a tie rod. Therefore, the outer size of the fuel cell stack 10 can be significantly reduced as compared with a fuel cell stack in which a backup plate that requires a hole forming margin for providing a through hole for passing a tie rod is used.
That is, since the size of the fuel cell stack 10 can be reduced, the space for mounting the fuel cell stack 10 on the vehicle body can also be reduced.

After the fuel cell stack 10 is disposed at a predetermined position of a vehicle body (not shown) such as an automobile (vehicle), a bolt (not shown) passed through a through hole 72 of each mounting boss portion 74 of the case 20. It is positioned and fixed to the vehicle body by being screwed into a bolt hole provided in the vehicle body.

The fuel cell stack 10 according to the present embodiment
Is basically configured as described above, and its operation and effect will be described next.

In order to cause the fuel cell stack 10 to generate power, first, a heater (not shown) arranged near the fuel cell stack 10 is energized. As a result, the fuel cell stack 10 is heated, and the temperature is raised to a predetermined operating temperature.

After the temperature of the fuel cell stack 10 is increased, a hydrogen-containing gas and an oxygen-containing gas are supplied from a hydrogen-containing gas supply source and an oxygen-containing gas supply source, respectively. Among them, the hydrogen-containing gas reaches the electrode catalyst layer of the anode 30 through the first gas inlet passage 48 and the first gas passage 44. Then, on the electrode catalyst layer, hydrogen in the hydrogen-containing gas is ionized according to the following reaction formula (A).

H ₂ → 2H ⁺ + 2e (A) Components other than hydrogen in the hydrogen-containing gas and unreacted hydrogen are supplied to the first gas passage 44 and the first gas outlet passage 50.
The gas is sent to the gas recovery mechanism via.

The hydrogen ions generated by ionization move through the electrolyte layer 34 and reach the electrode catalyst layer of the cathode 32. The electrons are taken out of the fuel cell through the current collecting electrode 16a, and are used as electric energy for energizing a load such as a motor (not shown). It reaches the electrode catalyst layer of the electrode 32.

On the other hand, the oxygen-containing gas flows through the second gas inlet passage 52 and the second gas passage 46 to the cathode 3.
The second electrode catalyst layer is reached. Then, the oxygen in the oxygen-containing gas is combined with the hydrogen ions and the electrons that have reached the electrode catalyst layer according to the following reaction formula (B).

O ₂ + 4H ⁺ + 4e → 2H ₂ O (B) Note that components other than oxygen in the oxygen-containing gas, unreacted oxygen, and generated water vapor are supplied to the second gas flow path 46 and the second gas flow path.
Air is supplied to the gas recovery mechanism via a gas outlet passage 54.

During this operation, the cooling water is supplied from the cooling water supply source so that the fuel cell does not exceed the predetermined temperature. This cooling water is supplied to the fuel cell stack 10
Through the cooling water passage 56a along the direction of the arrow A (see FIG. 1), is turned back in each unit cell 12, introduced into the cooling water passage 56b, and finally recovered by the cooling water recovery mechanism. You.

During operation, the fuel cell stack 10 undergoes thermal expansion to cause a dimensional change in the direction of arrow A. The disc spring 22 compresses in accordance with the dimensional change, and the end plate 18 Continue to fire the rocket. At this time, the end plate 18 is attached to the projection member 6 joined to the case 20.
Since the lateral groove 64 is slidably engaged with 8, the lateral groove 64 is guided by the projection member 68 and displaced in a direction approaching the stacked body 14. That is, the projection member 68 functions as a guide.
Therefore, the end plate 18 is prevented from skewing.

As a result, the pressure acting on one end surface of the laminated body 14 becomes substantially equal. That is, in the laminated body 14, a portion where pressure is applied more slowly than in other portions is less likely to occur, so that poor contact between the unit cells 12 is less likely to occur. In other words, since electrical contact between the unit cells 12 can be maintained, eventually
It is possible to prevent the power generation characteristics of the fuel cell stack 10 from deteriorating due to an increase in the internal resistance.

When the fuel cell vehicle on which the fuel cell stack 10 is mounted is run, a load acts on the fuel cell stack 10 due to vibration during running, repetition of starting and stopping, and the like. However, in this case, since the case 20 is rigidly connected to the vehicle body, the load can be sufficiently received. Therefore, it is possible to avoid a decrease in the pressure holding force on the laminate 14. That is, also in this case, electrical contact between the unit cells 12 can be maintained.

Moreover, in this case, the lateral groove 64 is
Since the end plate 18 is supported by the case 20 as a result of being engaged with the casing 8, the end plate 18 is not displaced except in a direction in which the end plate 18 approaches or separates from the stacked body 14. That is, the lateral groove 64 and the projection member 68
It also functions as a stopper for the end plate 18. Therefore, it is possible to prevent the end plate 18 from being detached from the fuel cell stack 10 via the upper end of the opening of the case 20.

As described above, in the present embodiment, the laminate 14 is housed in the case 20, and the laminate 14 is pressed and held by the end plate 18 urged by the disc spring 22. I have. Therefore, the size of the fuel cell stack 10 can be reduced while maintaining electrical contact between the unit cells 12 in the fuel cell stack 10. Further, the end plates 18 do not need to be provided at both ends of the laminated body as in the related art, and may be provided at least on one side. In addition, since there is no need to use a backup plate, the fuel cell stack 10 can be reduced in weight.

In the above-described embodiment, the lateral groove 64 is provided at the left and right end portions of the end plate 18 to form a concave portion. However, as shown in FIG. You may make it. in this case,
What is necessary is just to join the projecting member 68 to the bottom surface of the case 20. Of course, instead of the projection member 68, the projection may be provided by partially projecting the case 20 itself.

As shown in FIGS. 7 and 8, a columnar projection (convex portion) 82 is provided on the end face of the end plate 18 facing the case 20, and an insertion hole 84 (recess) is provided in the case 20. Alternatively, the projection 82 may be slidably inserted into the insertion hole 84.

Further, the shapes of the projection members and the projections (convex portions) are not limited to the prismatic or columnar shapes shown in FIGS. 1 to 8, but may be triangular or multiple. It may be square. In any case, the shape of the concave portion may be set so that the convex portion can be guided without being separated.

It goes without saying that the end plate 18 may be provided with a convex portion and the case 20 may be provided with a concave portion.

[0064]

As described above, according to the fuel cell stack of the present invention, the stacked body in which the unit cells are stacked is housed in the case, and the stacked body is formed by the end plate pressed by the pressing member. The pressure is maintained.

For this reason, since it is not necessary to use a tightening member such as a tie rod or the like, the outer size of the fuel cell stack is reduced by using a backup plate which requires a hole forming allowance for providing a through hole for passing the tie rod or the like. Remarkably smaller than that of a fuel cell stack. That is, downsizing can be achieved. Moreover, it is not particularly necessary to use two end plates as in the related art, and further, it is not necessary to use a backup plate. Therefore, the weight can be reduced. In addition, when the stack thermally expands and contracts due to the operation and shutdown of the fuel cell stack, and when the members constituting the fuel cell stack are sagged, the pressure holding force on the stack is reduced. Can also be avoided.

Further, since the concave portion or the convex portion provided on the end plate is slidably engaged with the convex portion or the concave portion provided on the case, contact failure occurs between the unit cells. It is possible to avoid that the internal resistance increases and the power generation characteristics of the fuel cell stack deteriorate. Also, the end plate can be prevented from coming off.

[Brief description of the drawings]

FIG. 1 is a schematic overall perspective view of a fuel cell stack according to the present embodiment.

FIG. 2 is a schematic plan cutaway view of the fuel cell stack of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part of a stack constituting the fuel cell stack of FIG. 1;

FIG. 4 is a schematic overall perspective view of a unit cell constituting the laminate of FIG. 3;

FIG. 5 is a schematic front cutaway view of the fuel cell stack of FIGS. 1 and 2;

FIG. 6 is a schematic front cutaway view of a fuel cell stack having a concave portion and a convex portion having a different shape from FIG. 5;

FIG. 7 is a schematic plan view cutaway view of a fuel cell stack having concave portions and convex portions having different shapes from FIGS. 5 and 6;

FIG. 8 is a schematic front cutaway view of the fuel cell stack of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Fuel cell stack 12 ... Unit cell 14 ... Stack 16a, 16
b: current collecting electrode 18: end plate 20: case 22: disc spring 30: anode side electrode 32: cathode side electrode 34: electrolyte layer 36: joined bodies 42a, 42
b: Separator 60 ... Support shaft 64 ... Lateral groove (recess) 66 ... Insertion hole 68 ... Projection member (convex) 74 ... Mounting boss 80 ... Ceiling groove (recess) 82 ... Projection (convex) 84 ... Insertion hole (Recess)

Claims (2)

[Claims] 1. A laminate comprising a plurality of unit cells each having a joined body having an electrolyte interposed between an anode electrode and a cathode electrode and a set of separators sandwiching the joined body. A fuel cell stack, comprising: an end plate that presses and holds the stack from an end of the stack; and a case that houses the stack and the end plate, between the end plate and the case. A pressing member for pressing the end plate toward the laminate is interposed. The end plate has a concave portion or a convex portion, and the case is slidably engaged with the concave portion or the convex portion. A fuel cell stack, wherein a convex portion or a concave portion is provided. 2. The fuel cell stack according to claim 1, wherein the fuel cell stack is mounted on a vehicle body, and the case includes a connecting member that connects the fuel cell stack and the vehicle body. A fuel cell stack provided with a mounting boss portion for passing therethrough.