Method for producing battery cells for electrical energy stores and production apparatus

Abstract

The invention relates to a method for producing battery cells with corresponding battery electrodes for electrical energy stores by means of a production apparatus (10), in which method a stacking process is carried out by means of a stacking device followed by a pressing process by means of a pressing device, said method having the steps of: - stacking corresponding electrode materials to form an electrode stack (12); - placing the resulting electrode stack (12) on a base plate (14) by means of respective hold-down devices (16) of the stacking device; - fixing a fixing plate (18) to a side (12a) of the electrode stack (12) opposite the base plate (14) by means of releasable fixing elements (20); - placing the base plate (14), the electrode stack (12) and the fixing plate (18) from the stacking device to the pressing device; - pressing the electrode stack (12) at a predefined pressure; and - releasing the fixing plate (18) by removing the releasable fixing elements (20). The invention also relates to such a production apparatus (10).

Description

[0001] Method for producing battery cells for electrical energy storage and production device

[0002] The invention relates to a method for producing battery cells with corresponding battery electrodes for electrical energy storage devices according to claim 1. Furthermore, the invention relates to a production device for producing such battery cells.

[0003] The production of electrical energy storage devices or batteries, especially all-solid-state batteries (ASSBs), is a current research area in the energy storage industry and thus well-known from the state of the art. The technical challenge lies in transferring an electrode stack from the stacking process to the pressing process without any displacement. Accordingly, solutions are being sought in connection with a critical phase of ASSB production.

[0004] The object of the invention is to provide a method and a manufacturing device by means of which the production of the electrical energy storage devices is particularly efficient with in particular few steps, in particular with regard to a simple and cost-effective way of assembling the respective electrodes.

[0005] This object is achieved by a method having the features of patent claim 1 and by a corresponding manufacturing device according to the invention. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0006] One aspect of the invention relates to a method for producing battery cells with corresponding battery electrodes, in particular for electrical energy storage devices for electrically powered motor vehicles, in particular passenger cars. This method combines a stacking process and a pressing process, which are carried out by special devices, namely a stacking device and a pressing device. To enable the production of the respective battery cells with corresponding battery electrodes, a plurality of steps are provided, which are not necessarily subordinate to a chronological sequence.

[0007] First, corresponding electrode materials, flexible materials, or thin electrodes are stacked in thin layers to form an electrode stack. This stacking process involves very precise alignment or stacking according to precise manufacturer specifications. The resulting electrode stack is then placed on a corresponding base plate, particularly one made of metal. The stacking device's hold-down devices are used to fix or hold the stack in the desired orientation during the stacking process. The hold-down devices are movable in such a way that they press the electrode stack against the base plate, preventing the respective electrode materials from shifting.

[0008] A fixing plate is then fixed to the side of the electrode stack opposite the base plate; this is secured using removably attached fixing elements. This ensures that the electrode stack is held stable by the fixing plate during transport from the stacking device to the pressing device. In other words, the fixing plate is designed to be larger in area than the electrode stack. To prevent the fixing plate from colliding with the hold-down devices, it is raised by spacers or block elements and only touches or clamps the stack in the area between the hold-down devices of the stacking device. This enables the hold-down devices to be extended without damage. The fixing plate can then be removed from the spacers and placed flat on the stack. Finally, pressing takes place, with the fixing plate still attached. The stack is never unclamped.After pressing, the fixing plate can be removed again.

[0009] The base plate, electrode stack, and fixing plate are pressed together and transferred to the press device to prepare for the further pressing process. The fixing plate is released by removing the previously attached removable fixing elements. This frees the electrode stack for the pressing process. Alternatively, there is also a design in which the screws or fixing elements do not need to be loosened before pressing. The stack is compressed during pressing, and the clamping effect of the fixing elements or screws decreases and disappears. The screws are located to the right and left of the pressing tool. The pressing tool moves down onto the stack between the fixing elements or screws.

[0010] In a final step, the electrode stack is pressed under high pressure to firmly bond the layers together and achieve the desired or specified density. Depending on the process requirements, this pressing process can also be carried out at elevated temperatures.

[0011] In other words, the transfer of the base plate, the electrode stack, and the fixing plate to the pressing device is necessary to prepare for the subsequent pressing process. In this context, the fixing plate is released by removing the previously attached fixing elements, making the electrode stack usable or pressable again. The path between the stacking device and the pressing device is secured by pressing the fixing plates or fixing plate against the base plates or base plate, thus compressing the electrode stack.

[0012] In an advantageous embodiment of the invention, it is provided that the fixing plate is bent by means of respective removable block elements for fixing. Accordingly, the fixing plate is fixed by bending with the aid of corresponding removable block elements. This bending makes it possible to remove the respective hold-down devices, since the bending creates a space through which the hold-down devices can be removed. These hold-down devices, which hold the electrode stack on the corresponding sides, are no longer needed for the pressing process. During this bending process, the electrode stack is held in place in a specific area, while in the other areas held by the hold-down devices, the hold-down devices can be removed without any displacement of the electrode materials.This method thus allows control of the fixation process and ensures that the electrode stack remains stable while the hold-down devices are removed for the pressing process.

[0013] In yet another advantageous embodiment of the invention, it is provided that a central region of the fixing plate is bent. This bending of the central region of the fixing plate makes it possible to stably fix the electrode stack in this provided region, while at the same time the other regions of the electrode stack held by the hold-down devices are accessible, whereby the hold-down devices can also be removed. In yet another advantageous embodiment of the invention, it is provided that the block elements are removed after fixing. In this case, it is provided that after the block elements have successfully fixed the fixing plate, they are removed, whereby the bending of the fixing plate is eliminated and the fixing plate now exerts uniform pressure on the entire electrode stack.

[0014] In yet another advantageous embodiment of the invention, the fixing elements, designed as screw elements, are guided through corresponding through-openings in the fixing plate. This means that the fixing elements are designed as screws or screw elements and can be pushed or guided through the through-openings in the fixing plate. This results in a particularly simple method of fixing the fixing element to the base plate, whereby other fixing elements are also possible, for example, screws with clips that can be attached to the edges of the fixing plate can also be used.

[0015] In another advantageous embodiment of the invention, it is provided that the fixing elements designed as screw elements are screwed into corresponding threaded openings in the base plate. Accordingly, the base plate comprises the respective threaded openings into which the fixing elements designed as screw elements or screws can be screwed. By providing respective threaded openings, a particularly precise alignment of the fixing plate relative to the base plate can be provided.

[0016] A further aspect of the invention relates to a manufacturing device for producing battery cells with corresponding battery electrodes for electrical energy storage devices, in which a stacking process can be carried out by means of a stacking device of the manufacturing device, followed by a pressing process by means of a pressing device of the manufacturing device. It is provided that corresponding electrode materials can be stacked to form an electrode stack, and the resulting electrode stacks can be placed on a base plate by means of respective hold-down devices of the stacking device. Furthermore, it is provided that a fixing plate can be fixed to a side of the electrode stack opposite the base plate by means of detachable fixing elements, and the base plate of the electrode stack, as well as the electrode stack and the fixing plate, can be placed from the stacking device to the pressing device.Finally, it is intended that the fixing plate can be removed by removing the detachable fixing elements, and that the electrode stack can be pressed under high pressure to produce the battery electrodes. In particular, the fixing plate is only released after pressing.

[0017] In a further advantageous embodiment of the invention, the fixing plate is designed to be deflectable in a central region by means of removable block elements for fixing. Accordingly, the fixing plate is made of a material that has an elastic modulus that allows for a certain amount of deflection.

[0018] In another advantageous embodiment of the invention, the block elements are removable after fixing. Thus, by removing the respective block elements, the fixing plate is moved from its bent position to a flat position, which compresses the electrode stack evenly across its entire upper surface.

[0019] In other words, the stack or electrode stack is secured by the hold-down devices. A metal plate which is larger than the entire stack is screwed into the free space between the hold-down devices. In the middle space, the plate clamps the stack. In the area of ​​the hold-down devices, contact is broken by bending the plate up with supports outside the stack, whereby the supports in this case are represented by the block elements. This allows the hold-down devices to extend without being touched by the clamping plate. The supports or block elements can then be removed from below or to the side, and the plate or fixing element or fixing plate rests fully on the stack. Alternatively, this securing process can be carried out using a two-part clamping and pressing plate system.

[0020] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features mentioned above in the description are combinations of features, as well as the features mentioned below in the description of the figures and / or shown alone in the figures. Combinations of features can be used not only in the respective specified combination, but also in other combinations or on their own.

[0021] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. Figure 1 shows a cross-sectional view of a base plate, an electrode stack, and a fixing plate to illustrate the method according to the invention.

[0022] In the figure, identical and functionally equivalent elements are provided with the same reference numerals.

[0023] Fig. 1 shows a cross-section of the base plate 14, the electrode stack 12, and the fixing plate 18 to illustrate a method for producing battery cells with corresponding battery electrodes for electrical energy storage devices, in particular for electrically powered motor vehicles. This method is carried out using a production device 10, wherein the method comprises a stacking process using a stacking device, followed by a pressing process using a pressing device of the production device 10.

[0024] Figure 1 shows the essential components, namely the base plate 14, the electrode stack 12 and the fixing plate 18.

[0025] The electrode stack 12 comprises the corresponding electrode materials that have been stacked. The base plate 14 serves as a support for the electrode stack 12 and is shown below the electrode stack 12 in Fig. 1. To secure the electrode stack 12 during the stacking process, respective hold-down devices 16 of the stacking device are used. These hold-down devices 16 hold the electrode stack 12 firmly on the respective sides, preventing the respective electrode materials from slipping.

[0026] On the opposite side of the base plate 14 is the fixing plate 18, which is secured by means of detachable fixing elements 20. The fixing elements 20 are guided through corresponding through-openings 20a in the fixing plate 18. The fixing elements 20 are designed as screw elements and can accordingly be screwed into corresponding threaded openings 14a in the base plate.

[0027] Furthermore, it is provided that the fixing plate 18 is bent by the action of the removable block elements 22. This is carried out in particular in a central region 18a of the fixing plate 18. This bending process thus makes it possible to hold the electrode stack 12 in place in the central region 18a, while the hold-down devices 16 on the sides of the stack can be removed without the electrode materials shifting.

[0028] After the hold-down devices have been removed, the block elements 22 are released or removed. This eliminates the deflection of the fixing plate 18, and the fixing plate 18 thus exerts uniform pressure on the entire electrode stack 12. This fixing plate 18 remains fixed during the pressing process, thereby firmly bonding the respective layers of the electrode stack 12. Furthermore, it is also provided that the fixing plate 18, prior to fixing, has a larger surface area than the stack surface 12b of the electrode stack 12 in order to enable uniform fixing and pressure distribution.

[0029] In summary, the invention proposes a fixing device for ASSB electrode stacks 12 or the manufacturing device 10, by which this electrode stack 12 is held with a force F and a corresponding counterforce -F during a process change.

[0030] List of reference symbols

[0031] 10 Manufacturing device

[0032] 12 electrode stacks

[0033] 12a Stacking surface

[0034] 14 Base plate

[0035] 14a Threaded openings

[0036] 16 hold-down clamps

[0037] 18 Fixing plate

[0038] 18a middle section

[0039] 20 fixing elements

[0040] 20a Passage opening

[0041] 22 block elements

[0042] F, -F forces

Claims

Patent claims 1. A method for producing battery cells with corresponding battery electrodes for electrical energy storage devices by means of a production device (10), in which a stacking process is carried out by means of a stacking device followed by a pressing process by means of a pressing device, comprising the steps: - stacking corresponding electrode materials to form an electrode stack (12); - placing the resulting electrode stack (12) on a base plate (14) by means of respective hold-down devices (16) of the stacking device; - fixing a fixing plate (18) on a side (12a) of the electrode stack (12) opposite the base plate (14) by means of detachable fixing elements (20); - Placing the base plate (14), the electrode stack (12) and the fixing plate (18) from the stacking device to the pressing device; - pressing the electrode stack (12) under a predetermined pressure; and - Loosen the fixing plate (18) by removing the removable fixing elements (20).

2. Method according to claim 1, characterized in that the fixing plate (18) is bent by means of respective removable block elements (22) for fixing.

3. Method according to claim 2, characterized in that a central region (18a) of the fixing plate (18) is bent.

4. Method according to claim 2 or 3, characterized in that the block elements (22) are removed after fixing.

5. Method according to one of the preceding claims, characterized in that the fixing elements (20) designed as screw elements are corresponding passage openings (20a) in the fixing plate (18).

6. Method according to claim 5, characterized in that the fixing elements (20) designed as screw elements are screwed into corresponding threaded openings (14a) in the base plate (14).

7. A manufacturing device (10) for producing battery cells with corresponding battery electrodes for electrical energy storage devices, in which a stacking process can be carried out by means of an arranged stacking device followed by a pressing process by means of an arranged pressing device, wherein corresponding electrode materials can be stacked to form an electrode stack (12), the resulting electrode stacks (12) can be placed on a base plate (14) by means of respective hold-down devices (16) of the stacking device, a fixing plate (18) can be fixed to a side (12a) of the electrode stack (12) opposite the base plate (14) by means of detachable fixing elements (20), the base plate (14), the electrode stack (12) and the fixing plate (18) can be placed from the stacking device to the pressing device, the electrode stack (12) can be pressed under a predetermined pressure and the fixing plate (18) can be removed by removing the detachable fixing elements (20).

8. Manufacturing device (10) according to claim 7, characterized in that the fixing plate (18) can be bent by means of respective removable block elements (22) for fixing in a central region (18a).

9. Manufacturing device (10) according to claim 8, characterized in that the block elements (22) are removable after fixing.

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