Device for producing individual electrode sheets for an energy cell from an electrode sheet material and method
Patent Information
- Application Number
- EP2023710350
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-14
- Filing Date
- 2023-03-10
- Publication Date
- 2025-01-22
AI Technical Summary
Mass production of energy cells, particularly batteries, requires high-speed separation of electrode sheets from electrode tracks with high accuracy to meet quality and production speed demands, as existing methods struggle to achieve both simultaneously.
A device comprising a contour cutting device and a cross-cutting device, with conveying means for unrolled transport, allows for synchronized cutting of contour cuts and cross-sections, utilizing a measuring device and control system to adjust and regulate the position of cuts, ensuring precise geometry and high production speed.
The solution enables the production of electrode sheets with high accuracy and speed, reducing errors and allowing for efficient assembly of energy cells with improved quality and increased production rates.
Smart Images
Figure 1.1
Abstract
Description
[0001] Device for producing individual electrode sheets for an energy cell from an electrode web and method
[0002] The present invention relates to a device for producing individual electrode sheets for an energy cell, in particular for a battery, from an electrode web according to the preamble of claim 1 and to a method for operating such a device according to the preamble of claim 11.
[0003] Energy cells or energy storage devices within the meaning of the invention are used, for example, in motor vehicles, other land vehicles, ships, aircraft or even in stationary storage systems in the form of battery cells or fuel cells, in which very large amounts of energy must be stored over longer periods of time.
[0004] Providing a sufficient quantity of energy cells, especially battery cells, requires mass-market manufacturing technologies with high production speeds. Among other things, the assembly of electrode sheets into finished cell stacks, energy cells, or battery cells presents a challenge. Separation processes are particularly important in the production of individual electrode sheets from electrode sheets for a stacked arrangement. Such separation processes are subject to stringent requirements in order to achieve the production speed required for mass production while maintaining the highest possible product quality.Against this background, the object of the invention is to provide a device for producing individual electrode sheets for an energy cell, in particular for a battery, from an electrode web, which enables the highest possible production speed with sufficient quality and accuracy.
[0005] To achieve this object, a device for producing individual electrode sheets for an energy cell, in particular for a battery, from an electrode web is proposed. The device comprises, downstream of an input region for the electrode web, a contour cutting device configured to create contour cuts on at least one of the two edges of the electrode web. The device comprises, downstream of the contour cutting device, in particular downstream of the electrode web in the conveying direction, a cross-cutting device configured to separate the electrode web into individual electrode sheets by creating cross-cuts. The device comprises conveying means for transporting the electrode web uncoiled from the contour cutting device to the cross-cutting device.
[0006] The electrode web is preferably a conductive electrode foil made of metal, which is further preferably coated with an active anode or cathode material. Furthermore, the anode or cathode material is preferably already calendered on the electrode foil, so that the electrode sheets separated from the electrode web can subsequently be fed into a process for forming an energy cell or battery. The electrode web is conveyed in a conveying direction and is preferably endless. A contour cut at the edges of the electrode webs is a cut which, in principle, at least not completely separates the electrode web transversely to the conveying direction. Accordingly, the contour cutting device does not separate the electrode sheets into electrode sheets, and the electrode web remains as such until the transverse cutting device.The contour cut is made on at least one of the two edges of the electrode track, so that, for example, a terminal tab for electrical contact can be formed on one of the edges. Furthermore, the contour cuts can also be used to create rounded corners or shoulders for the subsequent electrode sheets. The contour cuts have a longitudinal cut component, i.e., along the conveying direction parallel to the path of the electrode track, and a cross-sectional component, which accordingly runs perpendicular to the conveying direction. The contour cuts produced can also be referred to as notching.
[0007] In a typical contour cut, the corners of electrode sheets that are still connected in this state are rounded, creating a tapered area at the intended dividing line between the electrode sheets. These tapered areas are preferably repeated on both edges at a distance equal to the intended width of the individual electrode sheets.
[0008] The cross-cutting device separates the intended electrode sheets from the electrode web through the cross-section. The position of the cross-sections relative to the previous contour cuts is crucial for achieving the intended geometry of the produced electrode sheets. This can be advantageously achieved by transporting the electrode web from the contour cutting device to the cross-cutting device without being rolled up. The contour cutting device and cross-cutting device can thus be easily adjusted to one another, as direct adjustment to one another is possible by avoiding rolling up during transport or for transport. The electrode web is preferably conveyed directly from the contour cutting device to the cross-cutting device without additional deflections, for example on driven and / or non-driven rollers.In alternative embodiments, as few deflections as possible are provided in order to keep the path length of the electrode path between the contour cutting device and the cross-cutter device short.
[0009] The proposed device enables the simultaneous production of contour cuts and cross-sections. By avoiding transfer in the rolled-up state by transporting the electrode sheet in the unrolled state from the contour cutting device to the cross-cutting device, the respective cuts can be adjusted particularly well relative to one another. This can also be further facilitated by a small distance in terms of the length of the electrode sheet between the contour cutting device and the cross-cutting device, since additional tolerances, for example due to stretching of the electrode sheet, can be reduced. Due to the improved adjustability, electrode sheets can be manufactured with high geometric accuracy, even at higher production speeds.
[0010] According to a further development, it is proposed that the contour cutting device and the cross-cutting device be configured for synchronized operation with each other. Accordingly, the contour cutting device and the cross-cutting device preferably have the same operating speed and the same operating cycle.
[0011] It is further proposed that the device comprises a measuring device which is configured to determine the position of contour cuts or features of contour cuts relative to cross sections or relative to the cross-cutting device.
[0012] Features of contour cuts can, for example, be sections with pure cross-sectional components, for example on a connecting lug. However, particularly suitable features of contour cuts are tapered contours in the unseparated state or roundings or shoulders with tapered radii in the separated state of the electrode blades. The measuring device preferably measures the position of the contour cut relative to the cross-cutting device, in particular in the unseparated state of the electrode track. In a preferred embodiment, the measuring device measures the position of the contour cut relative to the cross-section, in particular the position of a tapered radius of the contour cut at the transition to a cross-section. If the cross-section does not lie exactly at the intersection point of the two preferred corner radii of two electrode blades, a pointed, needle-like and sharp-edged strip forms.Such streaks represent a defect that must be avoided at all costs, as movement or vibration of the cell stack can damage the separator film, which could lead to battery cell failure. Determining the position using the measuring device enables, among other things, precise adjustment of the contour cutting device or the contour cuts to the cross-cutting device or the cross-cuts. Furthermore, electrode sheets with a corresponding defect can be ejected from the production process.
[0013] According to a further development, it is proposed that a dancer unit be provided between the contour cutting device and the cross-cutting device for adjusting the position of the contour cuts or the position of features of the contour cuts relative to cross-sections. Using the dancer unit, fine adjustment or adjustment of the contour cuts and cross-sections relative to each other can be easily achieved by adjusting the web tension of the electrode web.
[0014] It is further proposed that the conveying means comprise conveyor rollers that can be driven at different circumferential speeds to adjust the position of the contour cuts or the position of features of the contour cuts relative to cross sections. Accordingly, the resulting slippage on individual conveyor rollers makes it possible to very precisely adjust the web tension of the electrode web and thus also the position of the contour cuts and the cross sections relative to each other.
[0015] In an advantageous embodiment, it is proposed that the contour cutting device be configured to adjust the position of the contour cuts or the position of features of the contour cuts relative to the cross-cutting device. Due to the unrolled transport of the electrode web from the contour cutting device to the cross-cutting device, such an adjustment enables the precise adjustment of contour cuts to cross-sections.
[0016] In a further advantageous embodiment, it is proposed that the cross-cutting device be configured to adjust the position of the cross-sections relative to the contour-cutting device. In this embodiment, due to the unrolled transport of the electrode web from the contour-cutting device to the cross-cutting device, such an adjustment can also enable the precise adjustment of contour cuts to cross-sections.
[0017] According to a further development, it is proposed that the device has a control device which is designed to control the position of the contour cuts or the position of features of the contour cuts relative to the cross sections of the cross-cutting device on the basis of the position determination.
[0018] For this purpose, the control device preferably receives the position of the contour cuts or the features of the contour cuts relative to the cross sections or the cross-cutting device, determined by the measuring device. Furthermore, the control device controls, for example, the proposed dancer unit, the driven conveyor rollers, and / or other proposed measures for adjusting the position of the contour cuts relative to the cross sections. Thus, the position of the contour cuts relative to the cross sections can be controlled during the manufacturing process, which significantly reduces the associated defects.
[0019] In particular, the control device enables a significantly higher path speed of the electrode path or a significantly increased production speed.
[0020] It is further proposed that the device comprise a stacking device configured to stack the separated electrode sheets with additional sheets. This allows, for example, the conveying paths to be kept particularly short, so that cell stacks for energy cells or battery cells can be formed from the separated electrode sheets and the additional sheets.
[0021] In an advantageous embodiment, a roll cutter is provided, which is configured to longitudinally cut a plurality of electrode tracks from an electrode roll. Using the roll cutter, the electrode tracks can be slit lengthwise, for example, as they are unrolled, and then fed to the contour cutting device or several contour cutting devices.
[0022] To achieve the object, a method for operating a device according to one of claims 1 to 10 is further proposed, comprising the following steps:
[0023] - Cutting contour cuts on at least one of the two edges of the electrode track by the contour cutting device;
[0024] - Conveying the electrode web in the unrolled state from the contour cutting device to the cross cutting device;
[0025] - Cutting of cross sections and separating of the electrode track into individual electrode sheets by the cross cutting device.
[0026] By means of the proposed steps in the device, a high production speed can be achieved with simultaneously high quality and dimensional accuracy of the cuts, especially of the individual cuts to each other.
[0027] According to a further development, it is proposed that the cutting of contour cuts by the contour cutting device and the cutting of cross-sections by the cross-cutting device be synchronized. The contour cutting device and the cross-cutting device therefore preferably operate in synchronization, with the cross-cutting device setting the synchronization in advantageous embodiments.
[0028] In a preferred embodiment, the position of a contour cut or a feature of a contour cut relative to a nearest cross-section is measured by the measuring device. This allows the alignment of the contour cutting device to the cross-cutting device to be directly detected and thus evaluated.
[0029] According to a further development, it is proposed that the position of the respective contour cuts or the respective features of the contour cuts relative to the nearest cross-section be controlled by a control device to a target position relative to each other. This control enables very high production speeds and is suitable for dynamically adjusting the contour cuts and cross-sections to each other, even with different production speeds or changes in production speed. Overall, significantly higher production speeds can thus be achieved.
[0030] Preferably, a dancer unit for controlling the position of the respective contour cuts or the respective features of the contour cuts relative to the nearest cross section is adjusted to a relative target position. This allows for simple control of the target position relative to each other.
[0031] In another possible embodiment, conveyor rollers of the conveyor are driven at differential circumferential speeds to regulate the position of the respective contour cuts or the respective features of the contour cuts relative to the nearest cross section to a target position relative to each other. The resulting slippage of the electrode track on the respective conveyor rollers can be used to change the tension of the electrode track, which changes the position of the contour cuts relative to the cross sections.
[0032] The invention will be explained below using preferred embodiments with reference to the attached figures.
[0033] Fig. 1 is a schematic representation of an apparatus for producing individual electrode sheets from an electrode web;
[0034] Fig. 2 an electrode track with contour cuts on both sides;
[0035] Fig. 3 an electrode track and individual electrode sheets;
[0036] Fig. 4 shows a possible error pattern at the transition from contour cut to cross section;
[0037] Fig. 5 a device with measuring device, control device and dancer unit; and
[0038] Fig. 6 a device with roll cutter and stacking device.
[0039] Figure 1 shows a schematic representation of an embodiment of a device 10 for producing individual electrode sheets 11 for an energy cell, in particular a battery, from an electrode sheet 12. The battery can, for example, be a lithium-ion battery with anode and cathode sheets as electrode sheets, which are stacked with corresponding separator sheets. The electrode sheet 12 runs in a conveying direction (see symbolic arrow in Figure 1) through the input area 13 of the device 10 to a contour cutting device 14, which, in this advantageous embodiment, makes the contour cuts 15 and 16 (see Figure 2) on both sides of the edges 17, 18 of the electrode sheet 12.The electrode web 12 provided with the contour cuts 15, 16 is conveyed by the conveyor 21, which may, for example, comprise one or more conveyor rollers 24, as a web in an unrolled state to the cross-cutting device 19 within the same device 10 or machine. The cross-cutting device 19 separates the electrode web 12 into electrode sheets 11 through cross-cuts 20, see Figure 3.
[0040] Figure 2 shows, by way of example, an electrode track 12 in a plan view behind or after passing through the contour cutting device 14. The contour cuts 15, 16 run along the edges 17, 18 of the electrode track 12 and have longitudinal section components parallel to the conveying direction and cross-sectional components perpendicular to the conveying direction. The contour cut 15 at the edge 17 is made with the formation of connecting lugs 30 and fillets.
[0041] 31 at the corners of the future electrode sheets 11. The contour cut 16 at the edge 18 merely has corresponding rounding 31 for the corners of the future electrode sheets 11. The adjacent roundings 31 typically run along the intended dividing line between two future electrode sheets 11, forming a tapered contour.
[0042] 32 together. Figure 3 also shows the electrode track 12 in a top view, wherein the cross-sections 20 made by the cross-cutting device 19 and the additional spacing of the individual electrode blades 11 from one another in this exemplary embodiment can be seen. With this possible geometry of the electrode blades 11, the cross-section 20, which separates the electrode blades 11 from the electrode track 12, runs through the tapered contours 32, so that the geometry of the electrode blades has rounded corners or fillets 31. The fillets 31 can also be referred to as shoulders on the side of the contour cut 15, each with a connecting lug 30.
[0043] Figure 4 shows a possible error pattern at the transition from a contour cut 15 to a cross section 20, which can occur if the cross-cutting device 19 is not optimally adjusted and the cross section 20, as a result, does not run exactly through the intersection points of the radii of the fillets 31. With this exemplary geometry of the electrode blades 11, the cross section 20 ideally runs through the tapered contour 32. As shown schematically on the left in Figure 4, the cross section 20 does not lie on the intended dividing line, which connects the tapered contours 32 in this exemplary embodiment (see also Figure 3), and thus does not run through the two tapered contours 32, which generally represent a possible feature of a contour cut 15, 16.In Figure 4 on the right, after spacing the two electrode sheets 11, it can be seen that the incorrect cutting position of the cross section 20 creates a sharp-edged strip, which, when used in an energy cell or battery cell, can, for example, damage the separator film and render the entire cell unusable. Such error patterns, as in Figure 4, can be avoided in particular by transporting the electrode sheet 12 from the contour cutting device 14 to the cross cutting device 19 without being rolled up, since this enables very good coordination of the position of the contour cuts 15, 16 to the cross sections 20 within a device 10 and synchronization of the cross cutting device 19 with the contour cutting device 14.
[0044] In advantageous embodiments, the device 10 has a measuring device 22 (see also Figure 5), which is configured to determine the position of contour cuts 15, 16 or features resulting therefrom, for example, the aforementioned tapered contours 32 between fillets 31, relative to the cross-section 20 or to the cross-cutting device 19. By means of such a measuring device 22, for example, a quality control and a corresponding adjustment of the device 10 can be carried out in a simple manner.
[0045] In a further possible embodiment, the device 10 has a control device 25, which preferably detects the position of the respective contour cut 15, 16 relative to the cross section 20, as determined by the measuring device 25, and controls the position of the contour cuts 15, 16 relative to the cross section 20 to a target position relative to one another. For this purpose, the control device 25 controls, for example, a dancer unit 23, which accordingly influences the web tension of the electrode web 12. Due to this control, it can be ensured that, for example, the cross sections 20 each lie in the tapered contour 32 or the tapered contours 32 on both sides of the electrode web 12. The control of the control device 25 can significantly increase the web and production speed.Figure 6 schematically shows another embodiment of a device 10, which has a roll cutter 28 on the input side, which cuts a plurality of electrode tracks 12 from an electrode roll 29. These electrode tracks 12 are then separated from one another and provided with a contour cut 15, 16 and a cross-section 20 for singulation. In advantageous embodiments, the device 10 can be configured to process a plurality of electrode tracks 12 in parallel or to produce electrode sheets 11.
[0046] Furthermore, in this advantageous embodiment, a stacking device 26 of the device 10 is provided, in which the produced electrode sheets 11 are stacked with further sheets 27, for example with complementary electrode sheets, ie, anode or cathode sheets and separator sheets 26. The stacks produced by the stacking device can, for example, be one or more dry monocells of a battery.
[0047] List of reference symbols
[0048] 10 Device
[0049] 11 Electrode sheet
[0050] 12 Electrode track
[0051] 13 Entrance area
[0052] 14 Contour cutting device
[0053] 15 Contour cut
[0054] 16 Contour cut
[0055] 17 edge
[0056] 18 edge
[0057] 19 Cross cutting device
[0058] 20 Cross section
[0059] 21 funding
[0060] 22 Measuring device
[0061] 23 Dancer Unit
[0062] 24 conveyor rollers
[0063] 25 Control device
[0064] 26 Stacking device
[0065] 27 additional sheets
[0066] 28 roll cutters
[0067] 29 Electrode roll
[0068] 30 connection lug
[0069] 31 fillets
[0070] 32 tapered contour
Claims
Claims:
1. Device (10) for producing individual electrode sheets (11) for an energy cell, in particular for a battery, from an electrode web (12), characterized in that - the device (10) has a contour cutting device (14) after an entry area (13) for the electrode track (12), which is set up to produce contour cuts (15, 16) on at least one of the two edges (17, 18) of the electrode track (12), - the device (10) behind the contour cutting device (14) has a cross-cutting device (19) which is set up to separate the electrode path (12) into individual electrode sheets (11) by creating cross-sections (20), wherein - the device (10) has conveying means (21) for the unrolled transport of the electrode web (12) from the contour cutting device (14) to the cross cutting device (19).
2. Device (10) according to claim 1 , characterized in that - the contour cutting device (14) and the cross cutting device (19) are set up for synchronized operation with each other.
3. Device (10) according to claim 1 or 2, characterized in that - the device (10) includes a measuring device (22) which is used to determine the position of contour sections (15, 16) or features of contour sections relative to cross sections (20) or is arranged relative to the cross-cutting device (19). Device (10) according to one of the preceding claims, characterized in that - a dancer unit (23) is provided between the contour cutting device (14) and the cross-cutting device (19) for adjusting the position of the contour cuts (15, 16) or the position of features of the contour cuts (15, 16) relative to cross-sections (20). Device (10) according to one of the preceding claims, characterized in that - the conveying means (21) comprise conveying rollers (24) which can be driven at different circumferential speeds to adjust the position of the contour cuts (15, 16) or the position of features of the contour cuts (15, 16) relative to cross-sections (20). Device (10) according to one of the preceding claims, characterized in that - the contour cutting device (14) is configured to adjust the position of the contour cuts (15, 16) or the position of features of the contour cuts (15, 16) relative to the cross-cutting device (19). Device (10) according to one of the preceding claims, characterized in that - the cross-cutting device (19) is set up to adjust the position of the cross-sections (20) relative to the contour cutting device (14).
8. Device (10) according to claim 2 and one of claims 3 to 6, characterized in that - the device (10) has a control device (25) which is set up to control the position of the contour cuts (15, 16) or the position of features of the contour cuts (15, 16) relative to the cross-sections (20) of the cross-cutting device (19) on the basis of the position determination.
9. Device (10) according to one of the preceding claims, characterized in that - the device (10) has a stacking device (26) which is designed to stack the individual electrode sheets (11) with further sheets (27).
10. Device (10) according to one of the preceding claims, characterized in that a roll cutter (28) is provided which is configured for longitudinal cutting of a plurality of electrode webs (12) from an electrode roll (29).
11. Method for operating a device (10) according to one of the preceding claims, characterized by the steps: - Cutting contour cuts (15, 16) on at least one of the two edges (17, 18) of the electrode path (12) by the contour cutting device (14); - Conveying the electrode path (12) in the unwound state from the contour cutting device (14) to the cross cutting device (19); - Cutting cross-sections (20) and separating the electrode path (12) into individual electrode sheets (11) by the Cross-cutting device (19).
12. Method according to claim 11, characterized in that - the cutting of contour cuts (15, 16) by the contour cutting device (14) and the cutting of cross sections (20) by the cross cutting device (19) is synchronized.
13. Method according to claim 11 or 12, characterized by: - Measuring the position of each contour section (15, 16) or feature of a contour section (15, 16) relative to a nearest cross-section (20) by a measuring device (22).
14. Method according to claim 13, characterized by: - Rules governing the position of the respective contour sections (15, 16) or the respective features of the contour sections (15, 16) relative to the nearest cross-section (20) to a relative target position to each other by means of a control device (25).
15. Method according to claim 14, characterized by: - Adjusting a dancer unit (23) to regulate the position of the respective contour cuts (15, 16) or the respective features of the contour cuts (15, 16) relative to the nearest cross-section (20) to a relative target position to each other.
16. Method according to claim 14 or 15, characterized by: - Driving conveyor rollers (24) of the conveying medium (23) with differential circumferential speeds to control the position of the respective contour cuts (15, 16) or the respective features of the contour cuts (15, 16) relative to the nearest cross-section (20) towards a relative target position- each other.