WO2018130249A1 - Device and method for producing a fuel cell stack - Google Patents

Abstract

A description is given of a method for producing a fuel cell stack in which at least one bipolar plate (12) and at least one membrane-electrode unit (5) are joined together to form a pre-stack (25) in a first stacking unit (23) of a device for producing a fuel cell stack, the pre-stack (25) is transported to a second stacking unit (24) of the device for producing a fuel cell stack, and subsequently the pre-stacks (25) are joined together to form a fuel cell stack in the second stacking unit (24) of the device for producing a fuel cell stack. A description is also given of a device for producing a fuel cell stack, which comprises a first stacking unit (23), for forming a pre-stack (25) from at least one bipolar plate (12) and at least one membrane-electrode unit (5) for a fuel cell stack, a second stacking unit (24), for forming a fuel cell stack from the pre-stacks (25) formed in the first stacking unit (23), and also a transporting device (1), for transporting the pre-stack (25) from the first stacking unit (23) to the second stacking unit (24).

Description

 DESCRIPTION

The invention relates to a device and to a method for producing a fuel cell stack.

Fuel cells are used to generate electricity, in particular from hydrogen, but also from methanol. The chemical reaction energy, for example, of hydrogen as a fuel, and an oxidizing agent,

especially of oxygen, converted into electrical energy. The fuel cell consists in particular of electrodes, on which the electrochemical reaction takes place, of an electrolyte arranged between the electrodes,

for example, a membrane through which ions, for example hydrogen ions, from one electrode, the anode, to the other electrode, the cathode, can migrate, and from bipolar plates, through which the hydrogen and the oxygen is supplied and distributed to the electrodes. A cell thus consists at least of a bipolar plate for supplying the fuel, an electrode (anode), a membrane or a

Electrolyte, another electrode (cathode), which is separated from the first electrode by the membrane, and another bipolar plate through which the

 Oxidationsm ittel is supplied. This results in a layered structure for a cell of a fuel cell. This can have further layers, for example

Gas diffusion layers. To generate sufficient voltages, has a

Fuel cell usually a plurality of cells thus formed, which are arranged adjacent and thereby a fuel cell stack, also referred to as fuel cell stack form. Fuel cell stacks are made by sequentially stacking and bonding the individual layers together. If errors occur in one of the layers, they are often only detected when all the layers have been connected to form a fuel cell stack. A correction of the error is then usually no longer possible, so that usually the entire fuel cell stack is unusable.

 The present invention is therefore based on the object to provide a method and a device with which it is possible to be able to test layers individually before they are assembled into a fuel cell stack.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 6. advantageous

Embodiments of the invention will become apparent from the dependent claims. In a method according to the invention for producing the fuel cell stack, in a first stacking unit of a device for producing a

Fuel cell stacks assembled at least one bipolar plate and at least one membrane electrode assembly to a pre-stack. The thus generated

Pre-stacks are then transported to a second stacking unit of the device for producing a fuel cell stack. There, the pre-stack is then joined to form a fuel cell stack in the second stack unit of the device for producing a fuel cell stack. The pre-stack can only one bipolar plate and a membrane-electrode unit, or more

Have bipolar plates and membrane electrode assemblies.

Characterized in that in the first stacking unit of the device for producing a

Fuel cell stacks can be generated first pre-stack, this can up

Manufacturing errors, which may arise in particular during assembly, are checked before the pre-stack in the second stacking unit of the device for

Making the fuel cell stack are joined to the fuel cell stack. The manufacturing errors may be, for example, errors in the positioning of the individual layers, or the tightness between the individual layers. Furthermore, by the method according to the invention, in particular by the prefixing between the bipolar plate and the membrane-electrode unit, the emergence of a "cracking frog" or a fanning between the layers can be prevented.

In an advantageous embodiment of the method according to the invention, in each case a bipolar plate and a membrane-electrode unit are assembled in the first stacking unit to the prestacking. The pre-stack thus consists of exactly one bipolar plate and exactly one membrane-electrode unit. Preferably, but not necessarily, the (softer) membrane-electrode unit is placed on the (more stable) bipolar plate.

In a further advantageous embodiment of the method according to the invention in each case a bipolar plate and a membrane electrode assembly in the first stacking unit with one or more other layers, for example

 Gas diffusion layers, assembled to pre-stack. The pre-stack has in addition to one or more bipolar plates and one or more membrane-electrode unit on other layers, such as gas diffusion layers. In a further advantageous embodiment of the method according to the invention, when the at least one bipolar plate and the at least one membrane-electrode unit are assembled into a pre-stack, they are simultaneously fixed to one another, for example by gluing or positive locking. This process is also referred to as prefixing. A fixation of the layers of the pre-stack takes place before the final fuel cell stack is produced from the layers.

The prefixing can also be done simultaneously with several grippers.

In a further advantageous embodiment of the method according to the invention, a check is carried out on the position accuracy and / or tightness of the pre-stack after the formation of the pre-stack. This makes it possible to check individual layers before they are assembled into a fuel cell stack. A device according to the invention for producing a fuel cell stack according to the above-described inventive method comprises a first stacking unit for forming a pre-stack of at least one bipolar plate and at least one membrane-electrode unit for a fuel cell stack, a second stack unit for forming a fuel cell stack from the pre-stacking formed in the first stacking unit, as well as a transport device for transporting the pre-stack from the first stacking unit to the second stacking unit. In the first stacking unit, one or more bipolar plates and one or more membrane-electrode units and optionally also further layers are assembled into a pre-stack. The pre-stack is brought by the transport device to the second stacking unit, where a fuel cell stack is formed from the pre-stacking formed in the first stacking unit. In an advantageous embodiment of the device according to the invention, the first stacking unit comprises a magazine for receiving membrane-electrode units and a gripper for grasping and transporting a membrane-electrode assembly to a Vorfixierungsplatz and a magazine for receiving bipolar plates and a gripper for grasping and Transporting a bipolar plate to the Vorfixierungsplatz on. At Vorfixierungsplatz the pre-stacking is done by alternately superimposing at least one membrane electrode assembly and a

Bipolar plate and its fixing.

In an advantageous embodiment of the device according to the invention, the second stacking unit has a magazine for stacking pre-stacking to one

Fuel cell stack and a gripper for grasping and transporting a Vorstapels from the transport device to the magazine for stacking Vorstapeln to a fuel cell stack. In a further advantageous embodiment of the device according to the invention, at least one of the magazines is a spindle magazine. This allows the delivery or positioning of the bipolar plate facing the gripper, membrane electrode Unit or already stacked stack relative to the gripper, so that the distance remains constant.

In a further advantageous embodiment of the device according to the invention, the gripper of the second clamping device is designed so that it engages excitingly on the bipolar plate in order to convey the pre-stack onto the already stacked stack. The bipolar plate is the more stable component. Alternatively, the gripper may also be on the soft side, i. at the membrane-electrode unit, attack. As a clamping or holding surface, the position of the lower adhesive surface is suitable. As clamping or

However holding surface can also be a separate tab on the membrane-electrode unit, the bipolar plate, or other sub-layers are suitable.

An embodiment of the device according to the invention will be described below with reference to the accompanying drawings. Show it:

1 shows an embodiment of a device according to the invention for carrying out the method according to the invention in a plan view,

2 shows the first stacking unit of the device from FIG. 1 in a side view, FIG. 3 shows the second stacking unit of the device from FIG. 1 in a side view, the device from FIG. 1 in a perspective view.

1 shows an embodiment of a device according to the invention for carrying out the method according to the invention for producing a fuel cell stack in a plan view.

The device has a first stacking unit 23 and a second stacking unit 24. The first stacking unit 23 and the second stacking unit 24 are by a

Conveyor 1 connected to each other. In the first stacking unit 23, in the embodiment shown in FIG. 1, in each case one bipolar plate 12 and one membrane-electrode unit 5 are stacked on top of one another to form a pre-stack 25 for a fuel cell stack / fuel cell stack. Bipolar plates 12 and membrane electrode assembly 5 are stored or stored in a magazine 3 for the membrane electrode assembly 5 and a magazine 10 for the bipolar plate 12 before they are stacked in the first stacking unit 23 for stacking.

For stacking the pre-stack, a single membrane-electrode unit 5 is removed from the magazine 3 for the membrane-electrode unit 5 by a gripper 6 for the membrane-electrode unit 5. From the magazine 10 for the bipolar plate 12, a single bipolar plate 12 is removed by a gripper 14 for the bipolar plate 12. The gripper 6 for the membrane electrode assembly 5 is at a

Linear portal 8 for the membrane electrode assembly 5 is arranged. The gripper 13 for the bipolar plate 12 is arranged on a linear portal 15 for the bipolar plate 12.

In the embodiment of the device according to the invention for stacking a fuel cell stack shown in FIG. 1, first in the magazine 10 for the

Bipolar plate 12 located bipolar plate 12 gripped by the gripper 13 for the bipolar plate 12 and brought to a Vorfixierungsplatz 22. The Vorfixierungsplatz 22 is arranged on a conveyor belt 1. The bipolar plate 12 is deposited by the gripper 13 on the Vorfixierungsplatz 22 and held on this by holding devices Vorfixierungsplatzes. Alternatively, the bipolar plate 12 on the

Vorfixierungsplatz 22 during subsequent placement of a membrane electrode assembly 5 on the bipolar plate 12 also held by the gripper 13 itself and thereby fixed on the Vorfixierungsplatz 22.

Subsequently, a single membrane-electrode assembly 5 is removed from the magazine 3 for the membrane-electrode assembly 5 by the gripper 6 for the membrane-electrode unit 5 and brought to Vorfixierungsplatz 22. It is placed there on the bipolar plate 12 already located on the Vorfixierungsplatz 22 and fixed on this. This process is called pre-fixation. This will be a

Pre-stack 25 (see Fig. 3) of the later fuel cell stack formed. The fixation of the membrane-electrode unit 5 on the bipolar plate 12 can by adhesive surfaces take place on the membrane-electrode unit 5 and / or the bipolar plate 12. However, the prefixing can also be done by other methods than by gluing, for example by positive engagement. The pre-fixing can also be done with several grippers simultaneously to one

Enable process parallelization. It also can

different orders of the layers to be stacked are selected to form the pre-stack. For example, the membrane-electrode unit 5 can first be deposited on the prefixing plate 22, and then the bipolar plate 12 is deposited on the membrane-electrode unit 5 and fixed thereto. Furthermore, other pre-stacking compositions can also be used on the

Prefix plate 22 can be generated. For example, additional layers, for example gas diffusion layers, can be fixed together with a bipolar plate 12 and a membrane-electrode unit 5. Then, additional magazines with respective grippers can be provided for these additional layers. In the prefixing, a plurality of bipolar plates 12 having a plurality of membrane electrode units 5 can also be constructed to form a pre-stack 25.

After prefixing, quality control of the pre-stack 25 formed thereby may be performed to detect faults prior to forming the entire fuel cell stack of a single layer before adding this pre-stack to the fuel cell stack. In particular, a check on position and / or tightness can take place. By prefixing the so-called.

"Crackpot" or fanning as unwanted errors are reduced

After prefixing, the pre-stack formed in the prefixing is transported by the conveyor belt 1 to the second stacking unit 24.

In the second stacking unit 24, the pre-stacking 25 formed in the prefixing is finished or, as far as finishing operations are completed, finished

Fuel cell stack 19, also referred to as a fuel cell stack formed, ie, a fuel cell stack, which has all layers of the finished fuel cell. In the second stacking unit 24 are by a gripper 16, on a linear portal 17th is arranged for the stack, the pre-stack formed in the prefixing 25 taken from the conveyor belt 1 and placed on a stack 21, which consists of

pre-stacking steps formed precompacting steps 25, which were stored in each case in previous steps on the stack 21. If, in each case, a bipolar plate 12 and a membrane-electrode unit 5 are fixed to one another during the prefixing, then this stack consists of alternating layers each having a bipolar plate 12 and a membrane-electrode unit 5

Successive placement of further pre-stacking formed in the prefixing, the finished fuel cell stack 19 is formed.

In the second stacking unit 24, the gripper 16 preferably grips and tensions the more stable component of the pre-stacks formed in the pre-fixing, i. however, it may also be on the softer side, i. the side of the membrane electrode assembly 5, are gripped and clamped. As a clamping or holding surface is particularly suitable, the position of the lower adhesive surface. However, a separate tab on the bipolar plate 12 or the membrane-electrode unit 5 or on other partial layers can also be used as the clamping or holding surface, which optionally may be formed separately therefrom. FIG. 2 shows the first stacking unit 23 of the device from FIG. 1 in a side view, viewed from the second stacking unit 24. In this case, the storage 10 and the gripping device 13 for the bipolar plates 12 and the storage 3 and the gripping device 6 for the membrane-electrode assemblies 5 are arranged on the right. In the Mite is the conveyor belt 1, the out of the picture plane out to the second

Stacking unit 24 leads, wherein on the conveyor belt 1 Vorfixierungsplatz 22nd

is arranged.

The magazine 3 for storing the membrane-electrode assemblies 5 is a spindle magazine 3 in the illustrated embodiment. The membrane-electrode assemblies 5 are arranged in the spindle magazine 3 on a base 4. This one is through two

Spindles 2 movable in the vertical direction. At the beginning of the manufacturing process, the spindle magazine 3 is filled with membrane electrode assemblies 5, preferably with the number of membrane electrode assemblies 5 in the fuel cell to be manufactured is needed. By the gripper 6, which is arranged in the illustrated embodiment preferably movable in the vertical direction on a vertical arm 7, wherein the arm 7 in turn preferably in a horizontal direction movable on a

Linear portal 8 is angeodnet, a membrane electrode assembly 5 is removed from the memory 3 in a Vorfixierungsschritt. The remaining in the memory 3 membrane electrode assemblies 5 are conveyed by a movement of the bottom 4 upwards, caused by the spindles 2, vertically upwards, so that the distance between the uppermost membrane electrode assembly 5 and the gripper 6 always stays the same. However, alternatively, the memory 3 may be formed so that the membrane-electrode units 5 are not moved, but at the removal of a membrane electrode assembly 5 of the gripper 6 has to reach slightly deeper into the memory 3 at each step.

The magazine 10 for storing the bipolar plates 12 is shown in FIG

Version also a spindle magazine. The bipolar plates 12 are in

 Spindle magazine 10 arranged on a bottom 1 1. This is movable by two spindles 9 in the vertical direction. At the beginning of the manufacturing process that is

Spindle magazine 10 filled with bipolar plates 12, preferably with the number

Bipolar plates 12, which is needed in the fuel cell to be manufactured. By the gripper 13, which is arranged in the illustrated embodiment preferably movable in the vertical direction on a vertical arm 14, wherein the arm 14 is again angeodnet preferably in the horizontal direction movable on a linear portal 15, in a Vorfixierungsschritt a bipolar plate 12 from the memory 10 taken. The remaining in the memory 10 bipolar plates 12 are conveyed by a movement of the bottom 1 1 upwards, caused by the spindles 9, vertically upwards, so that the distance between the uppermost bipolar plate 12 and the gripper 13 always remains the same. However, alternatively, the memory 10 may be so

be formed so that the bipolar plates 12 are not moved, but at the removal of a bipolar plate 12 of the gripper 13 has to reach slightly deeper into the memory 10 at each step.

In the illustrated embodiment, a bipolar plate 12 and a membrane-electrode unit 5 are each successively removed by the grippers 13 and 6 Saving 10 and 3 taken and brought to Vorfixierungsplatz 12, where they are superimposed and thereby fixed together. After a respective bipolar plate 12 and a membrane-electrode unit 5 are fixed together, the pre-stack 25 formed thereby is brought by the conveyor belt 1 to the second stacking unit 24, where the pre-stack formed in the prefixing to a

 Fuel cell stack are joined together. However, as described above, other layer sequences may be formed in the prefixing, or layers may be formed of a plurality of bipolar plates 12 and a plurality of membrane-electrode assemblies 5, or further layers may be added, e.g. Gas diffusion layers.

Fig. 3 shows the second stacking unit 24 of the apparatus of Fig. 1 in a side view. By means of the conveyor belt 1, the preliminary stacks 25 formed during prefixing are brought to the second stacking unit 24. By the gripper 16, which is arranged in the vertical direction and in the horizontal direction movable on the linear portal 17 of the second stacking unit 24, the pre-stacking formed in the pre-fixing 25 of

Conveyor belt 1 are lifted and placed on a stack 21, on which already the pre-stacking 25 generated at previous Vorfixierungsschritten are stored. This stack 21 lie on a bottom 20, which by a spindle 18 in

Essentially can be moved vertically. The bottom 20 can be lowered onto the stack 25 after each application of a pre-stack 25, so that the distance between the surface of the stack 21 and the gripper 16 always remains the same.

Alternatively, an immovable floor 20 may be provided. Then the gripper has to cover a different path each time the pre-stack 25 is applied.

By successively placing the prestacks 25 on the stack 21 in the second stacking unit 24, a fuel cell stack or fuel cell stack of a fuel cell is formed. The pre-stack can also be connected by fixing. The pre-stack can be inserted in the stack, for example, in frame members 19, fixing elements, etc., which cause a fixation of the individual layers together and can represent a frame, a housing or housing parts of the fuel cell. Fig. 4 shows the device of Fig. 1 in a perspective view. In particular, the first stacking unit 23 and the second stacking unit 24 can be seen.

LIST OF REFERENCE NUMBERS

1 conveyor belt

 2 spindle of the magazine for the membrane electrode units

3 Magazine for the membrane electrode units

 4 bottom of the magazine for the membrane electrode units

5 membrane electrode assembly

 6 grippers for the membrane-electrode units

 7 arm

 8 linear portal

 9 spindle of the magazine for the bipolar plates

 10 Magazine for the bipolar plates

 1 1 Bottom of the magazine for the bipolar plates

 12 bipolar plate

 13 grippers for the bipolar plates

 14 arm

 15 linear portal

 16 grippers for pre-stacking

 17 linear portal

 18 spindle of the magazine for the fuel cell stack

19 Frame / bracket / fixation for the fuel cell stack

20 bottom of the magazine for the fuel cell stack

 21 stacks, formed from the pre-stacks

 22 prefixing place

 23 first stacking unit

 24 second stacking unit

 25 pre-stack

Claims

1 . Method for producing a fuel cell stack, characterized by the following steps:  - Assembling at least one bipolar plate (12) and at least one  Membrane electrode unit (5) to a pre-stack (25) in a first  Stacking unit (23) of a device for producing a fuel cell stack, - Transporting the pre-stack (25) to a second stacking unit (24) of  Device for producing a fuel cell stack,  - Assembling the pre-stack (25) to a fuel cell stack in the second stacking unit (24) of the apparatus for producing a fuel cell stack. 2. The method according to claim 1, characterized in that  - In each case a bipolar plate (12) and a membrane-electrode unit (5) in the first stacking unit (23) to the pre-stack (25) are joined together. 3. The method according to claim 1 or 2, characterized in that in each case a bipolar plate (12) and a membrane-electrode unit (5) in the first stacking unit (23) with one or more other layers, for example Gas diffusion layers, to the pre-stack (25) are joined together. 4. The method according to any one of the preceding claims, characterized in that when assembling the at least one bipolar plate (12) and the at least one membrane-electrode unit (12) to a pre-stack (25) they are fixed together, for example by gluing or by positive locking. 5. The method according to any one of the preceding claims, characterized in that after forming the pre-stack (25), a check is made for position accuracy and / or tightness of the pre-stack (25). 6. An apparatus for producing a fuel cell stack according to a method according to one of claims 1 to 5, characterized in that the device comprises:  a first stacking unit (23) for forming a pre-stack (25) from at least one bipolar plate (12) and at least one membrane-electrode unit (5) for a fuel cell stack,  a second stacking unit (24) for forming a fuel cell stack from the precursors (25) formed in the first stacking unit (23),  - A transport device (1) for transporting the Vorstapels (25) from the first stacking unit (23) to the second stacking unit (24). 7. Apparatus according to claim 6, characterized in that the first stacking unit (23) comprises a magazine (3) for receiving membrane-electrode units (5) and a gripper (6) for grasping and transporting a membrane-electrode unit (5) to a prefixing station (22) and a magazine (10) for receiving bipolar plates (12) and a gripper (13) for grasping and Transporting a bipolar plate (12) to the Vorfixierungsplatz (22). 8. Apparatus according to claim 6 or 7, characterized in that the second stacking unit (24) comprises a magazine for stacking pre-stacks (25) into a fuel cell stack and a gripper (16) for grasping and transporting a pre-stack (25) from the transport device (1) to the stacks stacking magazine (25 ) to a fuel cell stack. 9. Apparatus according to claim 7 or 8, characterized in that at least one of the magazines is a spindle magazine. 10. Apparatus according to claim 8, characterized in that the gripper 16 of the second stacking unit (24) is designed so that it engages excitingly on the bipolar plate (12).