CUTTING METHOD AND CUTTING DEVICE FOR SEPARATING ELECTRODE PIECES FROM A WEB-SHAPED ELECTRODE SUBSTRATE

Description

[0001] The invention relates to a cutting method to be carried out during the series production of battery cell assemblies for separating electrode pieces from a web-shaped electrode substrate by means of a cutting device in order to obtain electrode pieces with a flat active material and a lateral conductor tab. The invention further relates to a cutting device for cutting and cutting electrode pieces from a web-shaped electrode substrate in order to obtain electrode pieces with flat active material and a lateral conductor tab for the series production of battery cell assemblies. The invention further relates to a computer program with control instructions for carrying out the cutting method and to a use of the cutting method or the cutting device or the computer program in the series production of battery cell assemblies, in particular for electric vehicles.

[0002] For the technological background, reference is made to the following literature, which shows such cutting processes and cutting devices: [1] WO 2020 / 192845 A1 [2] EP 3 415 265 A1 [3] https: / / www.youtube.com / watch?v=XStpCq pgZOg [4] https: / / www.youtube.com / watch?v=vXfJeHxbQKA [5] JP 2017 084691 A [6] US 2018 / 079035 A1

[0003] The separation of electrodes in battery cell production is carried out on an industrial scale by mechanical cutting or laser cutting.

[0004] In production, two cutting processes are usually involved: 1. Cutting out the conductor contour ("notching") 2. Separating the electrodes for separation

[0005] Normally, as can be seen from [3] and [4], the two processes take place in separate systems, i.e. the electrode material is unwound, notched and rewound in the first system. The coil is then fed into a second system where stacking takes place. There, the already notched webs are then separated by laser or mechanically to create the individual electrodes. In [3], [4] and [6], the processing is shown in two separate steps. There are separate systems for notching (cf. [3]) as well as combined processes (cf. [4], [6]). However, it can be seen that several units for web guidance and positioning are required between notching and separating (deflection rollers, rotating frames, etc.). One disadvantage of these processes is that many handling steps are necessary (separate systems, deflections between the processes in one system).These have a negative impact on the material and the risk of damage is very high. On the other hand, the linking of several independent process steps also increases the inaccuracy of the geometry, meaning that manufacturing tolerances must be defined more precisely.

[0006] In some cases, both processes are combined in one system, with the web being guided between the two processes via web guiding systems (rollers, web tension measuring rollers and rotating frames).

[0007] The reason for this is that the track must be positioned accurately before separation (lateral orientation) so that the geometry of the electrodes is achieved after separation.

[0008] A cutting device and a cutting method for separating the electrodes are known from [2]. Only one separating cut is performed on a roller. The additional cut for introducing a conductor contour is performed in an upstream process.

[0009] [1] and [5] each disclose a combined cutting and fixing device for producing cell composites, which already avoids many of the above-mentioned disadvantages. In particular, [5] discloses a method according to the preamble of claim 1 and a device according to the preamble of the dependent claim.

[0010] Based on [1] or [5], the invention aims to further improve the cutting of electrode pieces.

[0011] To achieve this object, the invention provides a cutting method and a cutting device according to the independent claims.

[0012] Advantageous embodiments are the subject of the dependent claims. A computer program with control instructions for automatically carrying out the cutting process and advantageous uses are the subject of the additional dependent claims.

[0013] According to one aspect thereof, the invention provides a cutting method to be carried out in the course of series production of cell assemblies of batteries for separating electrode pieces from a web-shaped electrode substrate by means of a cutting device in order to obtain electrode pieces with a flat active material and a lateral conductor lug, comprising the steps: a) Providing the web-shaped electrode substrate, which has an active material region and a conductor strip on at least one side of the active material region, by conveying the web-shaped electrode substrate to the cutting device; b) Cutting at least one conductor tab free from the conductor strip, whereby a section of unnecessary material of the conductor strip is created before and / or after the conductor tab in the conveying direction, c) Separating the electrode piece provided with the cut-out conductor tab by cutting through the electrode substrate including the active material and also the section cut out in step b), so that by cutting through the section, it is reduced in size and divided into several section parts, and d) Removing the section parts from the cutting device.

[0014] Preferably, the active material is a flat active material coated on one or both sides.

[0015] Preferably, an electrode substrate is provided which has an active material region coated on one or both sides and the conductor strip on at least one coating edge of the active material region.

[0016] The arrester strip is preferably an uncoated arrester strip or edge strip.

[0017] In particular, the web-shaped electrode substrate has an electrically conductive base layer that is coated on one or both sides with active material in the active material region to form the respective battery electrode and is uncoated on at least one edge strip, thus forming the conductor strip. In principle, such an electrode substrate is well known and commercially available.

[0018] Preferably, the web-shaped electrode substrate is conveyed into the processing field of cutting units of the cutting device.

[0019] Preferably, the cutting for separating and / or cutting through the electrode piece and / or the section takes place at least partially transversely to the web travel direction of the electrode substrate (conveying direction). In some embodiments, it is provided that, during the cutting for separating, cutting also takes place in or against the web travel direction. For example, the section is separated by a longitudinal cut.

[0020] In step d), a safe and complete removal of all section parts from the cutting device can be achieved, so that disruption of the cutting process for subsequent electrode pieces by remaining section parts is avoided.

[0021] Preferably, the removal is carried out by means of a suction device, which further preferably permanently sucks away the air or other ambient medium in the processing area of ​​the cutting units in order to avoid disruption of the cutting beams by particles generated during cutting.

[0022] In some embodiments, additional blowing units are provided to generate a directed air flow in conjunction with the extraction and to additionally protect the beam exit areas on the optics from contamination.

[0023] By cutting through the section, it is reduced in size and broken down into several sections, making it easier to remove and preventing disruption to the cutting process due to larger, defective sections remaining. This is generally possible with different cutting strategies, e.g., even with sequential operation of cutting units or, for example, when one cutting unit of the cutting device is used only to free the conductor lug, while the other cutting unit of the cutting device is used to cut through the electrode pieces and the section. Preferably, several cutting units of the cutting device operate synchronously, which leads to a shorter cycle time.

[0024] It is preferred that step a) comprises: a1) conveying the electrode substrate through two successively and / or overlappingly arranged working areas of a first cutting unit and a second cutting unit of the cutting device.

[0025] Preferably, step b) comprises cutting at least one conductor lug free from the conductor strip, whereby a section of unnecessary material of the conductor strip is created at least after the conductor lug in the conveying direction. The cutting can also be carried out in such a way that a section of unnecessary material of the conductor strip is also created before the conductor lug in the conveying direction. How the conductor lug is cut free depends on the format of the electrode. If, for example, an electrode format is to be produced in which the rear edge of the conductor corresponds to an edge of the active material (i.e. the conductor lug is located at the very rear of the electrode in relation to the conveying direction), the section is produced (only) in front (in the web running direction).

[0026] It is preferred that in step b) a first section located in front of the discharge lug in the conveying direction is cut out by means of the first cutting unit and at the same time, synchronously or with temporal overlap, a second section located behind this discharge lug in the conveying direction is cut out by means of the second cutting unit.

[0027] It is preferred that in step c) a front cut, seen in the conveying direction, is carried out by means of the first cutting unit and simultaneously, synchronously or at least temporally overlapping, a rear cut, seen in the conveying direction, is carried out by means of the second cutting unit.

[0028] To perform the anterior or posterior cut, a separating cut, in particular a transverse cut, is preferably performed.

[0029] Accordingly, it is preferred that multiple cutting units of the cutting device operate simultaneously or at least with temporal overlap. With temporal overlap, one cutting unit operates with a delay relative to the other cutting unit. With delayed operation, for example, the first cut (conductor contour + separating cut) is performed by a first scanner (example for the first cutting unit), and the second separating cut is performed with a temporal offset by a second scanner (example for the second cutting unit).

[0030] The processing areas or working areas of the first and second cutting units can be arranged entirely one after the other in the conveying direction (so that no overlapping area occurs). Preferably, the processing areas or working areas are offset from one another in the conveying direction, but overlap. This has the advantage of keeping the installation space of the cutting device as small as possible.

[0031] Preferably, the cutting process comprises the steps: Generating at least one cutting beam, in particular a laser beam, and directing the at least one cutting beam along cutting curves in order to carry out steps b) and c).

[0032] The at least one cutting beam is preferably directed by deflecting the at least one cutting beam. The directing or deflecting preferably occurs to separate an electrode and / or to cut the conductor lug free during the conveying process. Preferably, the cutting curves are provided as automatically calculated—in particular 3-dimensional—cutting paths, in particular laser paths, which take the conveying movement and / or the cutting position into account. The cutting paths are preferably dependent on the conveying movement and are adapted accordingly—preferably automatically—in the event of changes in the conveying movement.

[0033] It is preferred that step b) comprises: b1) directing the at least one cutting beam along a front cutting curve (in particular cutting path) which extends from a beam entry point in the interior of a region of the arrester strip forming the later unnecessary section of the arrester strip to a front corner region between a front arrester lug with respect to the conveying direction and the active material of the electrode piece and then extends outwards from the front corner region in a direction transverse to the conveying direction in order to separate the front arrester lug from the remaining unnecessary section of the arrester strip.

[0034] It is preferred that step b) comprises: b2) directing the at least one cutting beam along a rear cutting curve which extends from a beam entry point in the interior of the region of the conductor strip forming the later unnecessary section of the conductor strip to a rear corner region between a rear conductor lug with respect to the conveying direction and the active material of the electrode piece and then extends outwards from the rear corner region in a direction transverse to the conveying direction in order to separate the rear conductor lug from the remaining unnecessary section of the conductor strip.

[0035] It is preferred that step b) comprises: b3) directing the cutting beam along a central cutting curve which extends from the interior of the section to a corner region between a first conductor tab and the active material of the electrode piece, then in the conveying direction to produce an end edge of the active material of the electrode piece between the first conductor tab and a second conductor tab adjacent thereto and from the corner region between the second conductor tab and the active material into the interior of the section and ends there.

[0036] It is preferred that step c) comprises: c1) directing the at least one cutting beam along a singulation cutting curve extending from outside the conductor strip through the section transversely through the electrode substrate to singulate the electrode piece. Preferably, the cutting curve extends transversely through the electrode substrate in a coordinate system that moves with the electrode substrate; transferred to a stationary coordinate system, the cutting curve (e.g., laser path) is steeper or flatter depending on the path speed.

[0037] It is preferred that the cutting beam traverses the cutting curves one after the other, preferably with switching off or masking when jumping from one cutting curve to the next. In particular, the laser beam, preferably used as cutting beam, is switched on and off automatically by controlling the beam deflection units and the laser.

[0038] It is preferred that the middle cutting curve is traversed after the front and rear cutting curves.

[0039] It is preferred that the steps are carried out in the order b1), b2), b3) and c1).

[0040] It is preferred that d) comprises: blowing or sucking off the section parts.

[0041] Removal, particularly by blowing or suction, is preferably carried out locally and temporally directly at the point of origin.

[0042] According to a further aspect, the invention provides a cutting device for cutting and removing electrode pieces from a web-shaped electrode substrate in order to obtain electrode pieces with a flat active material and a lateral conductor lug for series production of cell assemblies of batteries, wherein the cutting device comprises: a cutting device, a conveying device for conveying a web-shaped electrode substrate, which has an active material region and a conductor strip on at least one side of the active material region, through a working area of ​​the cutting device, a section removal device for removing unnecessary sections created during cutting, and a controller configured to cause the cutting device to cut at least one conductor tab free from the conductor strip, whereby a section of unnecessary material of the conductor strip is created downstream of the conductor tab in the conveying direction, and to make a cut both through the electrode piece provided with the cut-out conductor tab and through the section cut out in step b) in order to separate the electrode piece and divide the section into several sections,to remove them using the section removal device.

[0043] The cutting device, and in particular its control system, is preferably designed to carry out the cutting method according to one or more of the advantageous embodiments of the method explained above. The cutting method is preferably carried out using a cutting device according to one of the advantageous embodiments of the device.

[0044] It is preferred that the cutting device comprises at least one cutting unit, which comprises a cutting beam generating device for generating a cutting beam, in particular a laser, and a cutting beam deflecting device, wherein the controller is configured to cause the cutting unit to direct the cutting beam along one or more predetermined cutting curves over the electrode substrate conveyed by the conveying device. Preferably, the controller is configured to cause the cutting unit to switch the cutting beam on or off according to the cutting curve. The cutting curves are preferably the cutting paths already mentioned above, which are automatically calculated as a function of the conveying movement, in particular laser paths for appropriately deflecting the laser radiation.

[0045] It is preferred that the cutting device comprises a first cutting unit with a first working area and a second cutting unit with a second working area, which are arranged one behind the other and / or overlapping in the conveying direction of the conveying device, and that the control, in particular a control unit thereof for controlling beam deflection units, is designed to cause the cutting device to to cut out a first section located in front of the arrester lug in the conveying direction by means of the first cutting unit and at the same time, synchronously or with temporal overlap, to cut out a second section located behind this arrester lug in the conveying direction by means of the second cutting unit, and / or to carry out a front cut as seen in the conveying direction by means of the first cutting unit and at the same time, synchronously or at least with temporal overlap, to carry out a rear cut as seen in the conveying direction by means of the second cutting unit.

[0046] It is preferred that the controller is configured to cause the cutting beam deflection device to b1) traverse a front cutting curve with the cutting beam, preferably at a predefined time, which extends from a beam entry point in the interior of a region of the arrester strip forming the later unnecessary section of the arrester strip to a front corner region between a front arrester lug with respect to the conveying direction and the active material of the electrode piece and then extends outwards from the front corner region in a direction transverse to the conveying direction in order to separate the front arrester lug from the remaining unnecessary section of the arrester strip.

[0047] It is preferred that the controller is configured to cause the cutting beam deflection device to b2) traverse a rear cutting curve with the cutting beam, which extends from a beam entry point in the interior of the region of the arrester strip forming the later unnecessary section of the arrester strip to a rear corner region between a rear arrester lug with respect to the conveying direction and the active material of the electrode piece and then extends outwards from the rear corner region in a direction transverse to the conveying direction in order to separate the rear arrester lug from the remaining unnecessary section of the arrester strip.

[0048] It is preferred that the controller is configured to cause the cutting beam deflection device to b3) traverse a central cutting curve with the cutting beam, which extends from the interior of the section to a corner region between a first conductor lug and the active material of the electrode piece, then in the conveying direction to produce an end edge of the active material of the electrode piece between the first conductor lug and a second conductor lug adjacent thereto and from the corner region between the second conductor lug and the active material into the interior of the section and ends there.

[0049] The control system is particularly designed to select, calculate and / or adjust the cutting curves, particularly in three dimensions, depending on the web speed and the absolute position of the web - in particular on the conveyor device.

[0050] It is preferred that the controller is configured to cause the cutting beam deflection device to c1) traverse with the cutting beam a singulating cutting curve which extends from outside the conductor strip through the section transversely through the electrode substrate for singulating the electrode piece.

[0051] It is preferred that the controller is configured to cause the cutting device and the conveying device and the section removing device to carry out the cutting method according to one of the preceding embodiments.

[0052] The section removal device preferably has a suction system, which preferably runs continuously during the cutting process and thus does not need to be actively controlled separately during the cutting process. In a preferred embodiment, a continuous suction system is required to enable the cutting process, in particular each laser cut.

[0053] In some embodiments, the cutting device has at least one additional blowing unit which, in conjunction with the suction, generates a directed air flow and additionally protects the beam exit areas on the optics from contamination.

[0054] According to a further aspect, the invention provides a computer program containing instructions that cause a cutting device according to one of the preceding embodiments to carry out the cutting method according to one of the preceding embodiments.

[0055] According to a further aspect, the invention proposes a use of the cutting method, the cutting device or the computer program according to one of the above advantageous embodiments of the invention in a series production of cell assemblies of batteries, in particular for electric vehicles.

[0056] Advantageous embodiments of the invention relate to a laser cutting method for separating electrodes. The method and device are preferably used in a large-scale production plant for battery cells. The battery cells are intended to be used in particular in electromobility, especially for at least partially or fully electric vehicles, such as cars or trucks.

[0057] In preferred embodiments of the invention, it is provided that a laser system comprising a pulsed laser and a 3D scanner with galvanometric axes is constructed to form at least one, several or all of the cutting units of the cutting device.

[0058] In preferred embodiments of the invention, the conductor cut (free cut) and the separating cut are performed on a vacuum roller. Thus, the path of the electrode substrate is not guided between the two cuts, and the material is permanently fixed (without relative movement) on the vacuum roller, preferably a cassette thereof.

[0059] Advantageous embodiments of the invention are based on the manufacturing process "cell stacking", whereby in the process described above the electrodes are usually separated in several steps (notching & separating cut).

[0060] Taking into account the high sensitivity of the electrode coating to mechanical influences, advantageous embodiments provide a solution in which the electrode can be separated in one cut if possible.

[0061] Furthermore, one of the key factors influencing the performance of a battery cell is the positioning accuracy of the individual layers on top of each other. High positioning accuracy and repeatability of the cutting process enable higher energy density in the cell. This is because the protrusion of the separator, which acts as an insulator between the electrodes, can be minimized through greater cutting accuracy. The resulting reduced installation space corresponds to an identical cell with a higher energy density.

[0062] Particularly preferred embodiments of the invention are based on the drum concept already described and shown in [1]. There, the electrodes are fixed and separated onto individual cassettes by means of a vacuum. In preferred embodiments of the invention, at least two scanners connected in series are provided as cutting units, with improved cutting strategies being provided compared to [1].

[0063] In some embodiments, the isolated electrodes are produced in two steps.

[0064] In one step, the conductor area, i.e. the area of ​​the electrode material that is not coated, is cut out.

[0065] The contour of the conductor lug can be designed with rounded corners or with sharp edges.

[0066] In a further step, the electrodes are separated. The laser beam cuts through the active material. Here, too, rounded corners can be introduced using the cutting curve.

[0067] The order of the two cuts, as well as the cutting direction, can be adjusted as desired due to the symmetrical structure.

[0068] Furthermore, it is conceivable to process two electrode tracks (or one track with two conductor strips that is separated in the middle upstream) synchronously by extending the arrangement with a third laser or scanner.

[0069] Preferred embodiments have at least one, several or all of the following advantages: The electrode contour can be manufactured with very tight tolerances because the electrodes are fixed to a cassette and remain stationary between the two process steps. The basic design of the vacuum roller with one or more cutting units allows for various cutting strategies, thus allowing for optimal adjustment of the cutting process to the cutting position in space, the electrode contour, the electrode material, and the laser parameters (scan feed, power, pulse duration, pulse repetition frequency, focus position). Cutting strategies of preferred embodiments are: Full cut: Each cutting unit (one or more) synchronously separates the electrodes from the web. This can be varied depending on the process speed and material during the cutting process. Option 1: The scanners operate synchronously, i.e., simultaneously. Option 2: The scanners operate at the optimal angle of incidence, i.e., the cut occurs essentially in the center of the working field. The scanners can also work "into each other" in the intersection area of ​​the working fields.

[0070] With a full cut: Very high cycle times can be achieved because the cutting units only have to cover a minimal jump distance (distance from the end of the cut to the start of the cut) between the contour cut and the severing cut. In addition, the synchronous full cut allows each individual cutting unit, e.g. each individual laser, more time to separate the electrode (increasing the part pitch). This means that the feed rate can be reduced while maintaining the same cutting edge quality. The jump distance / return distance can be adjusted depending on the path speed and the laser scanning speed. The positioning of the contours on the cylinder surface can be done by moving them in software. With a full cut with focus simultaneous cutting, a complete electrode sheet can be separated at a time t.The limiting factor is always the effective laser path length in conjunction with the path speed and the scan field area (= cassette spacing on the vacuum roller).

[0071] Other embodiments can also provide for a sequential cut, with one cutting unit cutting only a first portion of the electrode contour and another cutting unit performing a separating cut, also severing sections created during the cutting of the electrode contour. With a sequential separation cut, one of the lasers can be operated with different parameters than the other laser. The working field of the first scanner can be reduced to a minimum process area, thus also reducing the spot size and increasing the edge quality.

[0072] Examples of embodiments are explained in more detail below with reference to the attached drawings. They show: Fig. 1 is a partially perspective view and a partially schematic block view of an embodiment of a cutting device designed to carry out a cutting method for cutting electrode pieces; Fig. 2 is a plan view of a first embodiment of an electrode piece; Fig. 3 is a plan view of a second embodiment of an electrode piece; Fig. 4 is a plan view (in a flat development) of a web-shaped electrode substrate during the execution of a first step of a preferred embodiment of the cutting method; Fig. 5 is a view as in Fig. 4 when performing a second step of the cutting process; Fig. 6 a plan view (in a flat development) of a web-shaped electrode substrate as an overview illustration to explain the cutting process; Fig. 7 a plan view (in a flat development) of the web-shaped electrode substrate according to Fig. 6, wherein different cuts 1 to 4 of the cutting process of the preferred embodiment are indicated; Fig. 8 a plan view (in flat development) of a part of the web-shaped electrode substrate of Fig. 6 and 7 to explain sections 1 and 2 of the cutting method of the second embodiment; Fig. 9 a plan view as in Fig. 8 , wherein the implementation of cut 3 of the cutting method of the second embodiment is illustrated; and Fig. 10 is a plan view of an electrode track piece on which the contour of a conductor strip has already been cut out after implementation of the first step of the cutting method of the first embodiment, here in particular after implementation of cuts 1 to 3, wherein the implementation of a separating cut according to the second step and in particular according to cut 4 of the cutting method is illustrated.

[0073] In Fig. 1A preferred embodiment of a cutting device 10 with a cutting device 12 is shown, which is used in the course of large-scale production of batteries for electric vehicles for providing electrode pieces 14 to be stacked, as is basically known from [1]. Fig. 2 and 3 preferred embodiments of electrode pieces 14 to be formed by cutting are shown. In the Fig. 4 to 10 are different steps of a preferred embodiment of a cutting method for forming such electrode pieces 14, preferably using the cutting device 10 of Fig. 1 , shown (the cutting process can, however, be carried out with other cutting devices not shown in detail, e.g. with flat conveying).

[0074] This is a cutting process to be carried out during the series production of cell assemblies of batteries for separating electrode pieces 14 from a web-shaped electrode substrate 16 by means of a cutting device 12 in order to obtain electrode pieces 14 with a flat active material 18 and a lateral conductor lug 20. Preferred embodiments of the electrode pieces 14 are described in Fig. 2 and 3 shown.

[0075] As particularly in the Fig. 4 to 10 As shown, the cutting process includes the following steps: a) Providing the web-shaped electrode substrate 16, which has an active material region 22 preferably coated on one or both sides with active material 18 and a preferably uncoated conductor strip 24 on at least one side of the active material region 22, by conveying the web-shaped electrode substrate 16 to the cutting device 12; b) Cutting at least one conductor lug 20 free from the conductor strip 24, wherein at least in the conveying direction after the conductor lug 20 a section 26 of unnecessary material of the conductor strip 24 is created (see in particular Fig. 4 as well as Fig. 8 and 9 ), c) separating the electrode piece 14 provided with the cut-out conductor lug 20 by cutting through the electrode substrate 16 including the active material 18 and also the section 26 cut out in step b) (see in particular Fig. 5, 6 and 10) and d) removing the section parts 28 (in particular those created in step c) by cutting through the section 26) from the cutting device 12.

[0076] The Fig. 1 The embodiment of the cutting device 10 shown is therefore designed for cutting and cutting out electrode pieces 14 from a web-shaped electrode substrate 16, in particular in Fig. 2 and 3 The electrode pieces 14 shown here have a flat active material 18 and a lateral conductor tab 20 for series production of battery cell assemblies. In particular, the cutting device 10 is designed to carry out the aforementioned cutting method.

[0077] According to Fig. 1 the cutting device 10 comprises the cutting device 12, a conveyor device 30, a section removal device 32 and a controller 34.

[0078] The conveying device 30 is designed to convey the web-shaped electrode substrate 16 through a working area 36-1, 36-2 of the cutting device 12.

[0079] In the embodiment shown, the conveying device 30 is designed as a vacuum roller 38 which can be rotated about a rotation axis 42 by means of a rotary drive 40 and in which a vacuum can be generated by means of a suction device 44.

[0080] The vacuum roller 38 is shown in the illustration of Fig. 1 rotated clockwise, the direction of rotation here indicates a conveying direction 68 for conveying the Fig. 1 electrode substrate 16, not shown.

[0081] The peripheral surface 46 has a plurality of suction openings 48 so that the electrode substrate 16 and the cut-out electrode pieces 14 can be held thereto by suction. A plurality of cassettes 50 are movably arranged on the peripheral surface 46, so that one cassette 50 is provided for each electrode piece 14. The suction openings 48 are provided on the inner surface areas of the cassettes 50, outside the cutting curves 60, which will be explained later.

[0082] The cassettes 50 are movable in the radial direction by means of a slotted guide (not shown) depending on the rotational position in order to spatially separate the electrode pieces 14 cut by the cutting device 12 and to deliver them to a delivery point, in particular by blowing or suction. In particular, a vacuum roller 38, as described and shown in more detail in reference [1], is used. As described and shown in [1], the web-shaped electrode substrate 16 is delivered to the vacuum roller 38 and conveyed by the vacuum roller 38 through the working area 36-1, 36-2 of the cutting device 12, so that the entire cutting process, as explained in more detail below, is carried out on the vacuum roller 38.

[0083] The cutting (separating cut) takes place in particular in the gap area between adjacent cassettes 50. At the lateral edge area of ​​the circumferential surface 38, where the arrester strip 24 comes to rest and where the arrester lugs 20 are cut free, no suction openings 48 are provided in the embodiment shown.

[0084] The cutting device 12 has at least one cutting unit 52-1, 52-2, which has a cutting beam generating device 54 for generating a cutting beam and a cutting beam deflecting device 56. The controller 34 controls the cutting unit 52-1, 52-2 to direct the cutting beam along one or more predetermined cutting curves 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4 - examples of which are shown in the Fig. 4 to 10 are shown - over the electrode substrate 16 conveyed by means of the conveying device 30.

[0085] In the embodiments shown, the cutting beam generating device 54 is formed by a laser. In some embodiments, the cutting beam deflection device 56 is formed by a scanner, in particular a 3D scanner with galvanometric axes.

[0086] In the illustrated embodiment, the cutting device 12 comprises a first cutting unit 52-1 with a first working area 36-1 and a second cutting unit 52-2 with a second working area 36-2. The cutting units 52-1, 52-2 are each constructed by a laser system comprising a pulsed laser and a 3D scanner with galvanometric axes, each of which can direct the cutting beam to a point in the associated working area 36-1, 36-2.

[0087] The cutting units 52-1, 52-2 are arranged offset from one another in the circumferential direction of the vacuum roller 38, and thus in the conveying direction 68 of the conveying device 30, in particular one behind the other, wherein the first and the second working area 36-1, 36-2 can be arranged one after the other in the conveying direction 68 or, as shown, are arranged offset from one another with an overlapping area 58.

[0088] In the illustrated embodiments, the first cutting unit 52-1 is arranged at the front in the conveying direction 68 (bottom in Fig. 1 ), while the second cutting unit 52-2 is arranged at the rear in the conveying direction 68 (top in Fig. 1). The definition of "first" and "second" is arbitrary; here, the "first cutting unit 52-1" refers to the one that cuts further forward in the conveying direction 68. In practice, however, the electrode substrate 16 first passes through the working area 36-2 of the second cutting unit 52-2 and then through the working area 36-1 of the first cutting unit 52-1.

[0089] The section removal device 32 is designed to completely remove the sections 26, in particular by removing the smaller section parts 28. The removal takes place at the location and time of cutting off the section parts 28, preferably by suction or blowing. In preferred embodiments, the section removal device 32 has a suction device 62 that sucks particles generated during cutting away from the work area 36-1, 36-2 and from the vacuum roller 38. Preferably, the suction device 62 runs continuously. Before a cutting process is started, the controller 34 then queries the functional status of the suction device 62 and only performs a cutting process while the suction device 62 is running.

[0090] The control 34 is further designed to control the cutting units 52-1, 52-2 to travel through the cutting curves 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4, as will be described below with reference to the Fig. 4 to 10will be explained in more detail.

[0091] The cutting curves 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4 are laser paths along which the respective laser beam is guided for cutting. The cutting curves 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4 are automatically calculated by the control 34 depending on the conveying speed - in this case the rotational speed of the vacuum roller 38 - in order to carry out the cutting process during the conveying process. Furthermore, the control 34 carries out the cutting at the point marked with the circle with a cross in Fig. 4 to 10 designated beam entry points 64 (beginning of the respective cutting curve 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4) a switching on or fading in of the cutting beam, here laser beam, and at the points marked with a star symbol in the Fig. 4 to 10designated beam exit points 66 (end of the respective cutting curve 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4) switching off or masking out the cutting beam, here the laser beam.

[0092] As already explained, the laser system consists of at least one laser beam source and at least one optical deflection unit. After the separation process on the vacuum roller 38 has taken place, a spatial deflection of the laser beam (including height adjustment of the working plane) is provided. In preferred embodiments, a 3D scanner with galvanometric axes is used for this purpose.

[0093] In preferred embodiments, pulsed or continuous fiber lasers are used as the beam source.

[0094] The cutting curve 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4 or cutting curve for generating the individual electrodes 14 is created by synchronizing the rotational movement of the vacuum roller 38 and the cutting movement in the working area 36-1, 36-2 of the deflection unit of the cutting beam deflection device 56.

[0095] Since the cutting speed can vary – e.g., due to specific workpiece properties (format size, coating thickness, coating material, etc.) – various cutting strategies have been developed to maintain the cycle time. The system design with two (or more) cutting units 52-1, 52-2 allows for various cutting strategies, each of which offers different advantages.

[0096] In addition, depending on the material, the cuts can also be made over several passes.

[0097] The Fig. 2 and 3 show an overview of possible electrode shapes. Fig. 2shows an electrode piece 14 with a sharp-edged contour, while Fig. 3 shows an electrode piece 14 with a rounded contour.

[0098] In the Fig. 4 to 10 Examples of cutting curves 60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4 for cutting strategies for synchronous separation steps are shown.

[0099] In this case, Fig. 4 A schematic overview of a free cut 60b1, 60b2 of the conductor lug 20 by the first cutting unit 52-1 and the second cutting unit 52-2 is shown. The arrow 68 indicates the material flow or, in other words, the conveying direction of the conveyor device 30. In Fig. 5 The respective separating cut 60c1, 60c2 is shown schematically in overview by the first cutting unit 52-1 and the second cutting unit 52-2 (the more precise course of the separating cut 60c1, 60c2 is shown in Fig. 10 shown). In Fig. 6 is a schematic overview of the sequence of Fig. 4and 5 resulting cutting strategy with the jump 70 and the jump path 70-1, 70-2 of the first and second cutting unit 52-1, 52-2.

[0100] Accordingly, in the embodiment of the cutting method shown, in step b) a first section 26-1 located in front of the conductor lug 20 in the conveying direction 68 is cut out by means of the first cutting unit 52-1, and a second section 26-2 located behind this conductor lug 20 in the conveying direction 68 is cut out synchronously or at least temporally overlapping by means of the second cutting unit 52-2. Subsequently, in step c) a front cut as seen in the conveying direction 68 - here the separating cut 60c1 - is made by means of the first cutting unit 52-1, and a rear cut as seen in the conveying direction 68 - here the separating cut 60c2 - is made synchronously or temporally overlapping by means of the second cutting unit 52-2.

[0101] With this cutting strategy, both cutting units 52-1, 52-2, or scanners, operate synchronously. In the first cutting phase, the conductor – conductor lug 20 – is cut out. The scanner then separates the electrode.

[0102] An advantage of this cutting process is that - as in Fig. 10As shown, the section 26 of the collector strip 24, after being separated from the web in the first separation cut, is separated into two sections 28 by the immediately following transverse cut at the level of the gap between adjacent cassettes 50. By dividing the collector sections 26 (halving the weight to be extracted), the risk of not completely removing the section 26 from the process zone can be reduced. This minimizes the risk of the section 26 influencing the laser beam, which could thus disrupt the subsequent cut. After the sections 26 are extracted during the process, the section 26 can be halved again, and the risk of negative influences on the overall process can be significantly reduced.

[0103] In the Fig. 7A three-part cut of the respective free cut 60b1, 60b2 and the separating cut 60c1, 60c2 to be performed as the fourth cut are shown. Each overall cutting curve 60 of the respective cutting unit 52-1, 52-2 has the individual cutting curves 60.1, 60.2, 60.3, and 60.4.

[0104] In Fig. 8 The partial cuts 60.1 and 60.2 for cutting the edges in a direction transverse to the conveying direction 68 are shown. The cutting beam (e.g. laser) penetrates the corner or radius transition from the active material area to the arrester area and then runs upwards out of the arrester strip 24. Thus, in these first cuts 60.1, 60.2, the two Fig. 8vertically illustrated leg of the arrester. In the illustrated embodiment of the partial cuts 60.1, 60.2, the cutting beam enters at a beam entry point 66 in the interior of a region of the arrester strip 24, which region later forms the section 26 to be disposed of. Thus, any impairment of the material upon entry of the beam is irrelevant, since this area of ​​the material is disposed of as section 26 anyway. From the beam entry point 66, the cutting beam is then guided to the corner region 72 between the active material 18 and the edge of the arrester lug 20 to be cut free, where - depending on the contour of the electrode 14 - a rounding can be carried out. The cutting beam is then guided from the corner region 72 through the arrester strip 24 to the outside in order to cut the edge free and is then switched off.

[0105] In the Fig. 9In the partial section 60.3 of the free cut 60b1, 60b2 shown, the section 26 is cut off along the boundary of the active material 18 extending in the conveying direction 68. Here, too, the cutting beam enters the interior of the future section 26, is then guided to the corner region 72, and then guided along the boundary. The cutting beam is then guided again into the interior of the section 26 and then switched off or masked out.

[0106] The laser then penetrates the corner or radius transition again, but this time from the opposite direction. The cut then occurs parallel to the coating edge, which then tapers off again in the corner area.

[0107] Thus, the section 26 between two conductor lugs 20 is completely cut out.

[0108] Fig. 10shows the subsequent partial cut 60.4 for performing the separating cut 60c1 or 60c2 in greater detail. The cutting beam is guided from outside the electrode substrate 16, first through the section 26 of the conductor strip 24 and then through the active material region 22, in order to separate the electrode piece 14, which is located at the front in the conveying direction, from the remaining electrode substrate 16, essentially transversely to the conveying direction.

[0109] The laser separates the electrodes in a transverse cut, piercing above the separated area - section 26 - and thus further halving it.

[0110] Thus, according to Figs. 7 and 8 step b) of cutting free 60b1, 60b2 of the conductor lug 20 is preferably carried out with the steps: b1) Directing the at least one cutting beam along a front cutting curve 60.1, which extends from a beam entry point 66 in the interior of the region of the conductor strip 24 forming the later unnecessary section 26 of the conductor strip 24 to a front corner region 72 between a front conductor lug 20 with respect to the conveying direction 68 and the active material 18 of the electrode piece 14 and then extends outward from the front corner region 72 in a direction transverse to the conveying direction 68 in order to separate the front conductor lug 20 from the remaining unnecessary section 26 of the conductor strip 24; b2) Directing the at least one cutting beam along a rear cutting curve 60.2, which extends from a beam entry point 66 in the interior of the region of the arrester strip 24 forming the later unnecessary section 26 of the arrester strip 24 to a rear corner region 72 between a rear arrester lug 20 with respect to the conveying direction 68 and the active material 18 of the electrode piece and then extends outwards from the rear corner region 72 in a direction transverse to the conveying direction 68 in order to separate the rear arrester lug 20 from the remaining unnecessary section 20 of the arrester strip 24; b3) directing the cutting beam along a central cutting curve 60.3, which extends from the interior of the section 26 to a corner region 72 between a first arrester lug 20 and the active material 18 of the electrode piece 14, then in a direction parallel to the conveying direction 68 (e.g. takes place in . Fig. 9the cut 60.3 extends counter to the conveying direction 68) to produce an end edge of the active material 18 of the electrode piece 14 between the first conductor lug 20 and a second conductor lug 20 adjacent thereto and from the corner region 72 between the second conductor lug 20 and the active material 18 into the interior of the section 26 and ends there.

[0111] According to Fig. 10 the step c) of separating - separating cut 60c1, 60c2 - the electrode piece 14 is preferably carried out with the step: c1) directing the at least one cutting beam along a separating cutting curve 60.4, which extends from outside the conductor strip 24 through the section 26 transversely through the electrode substrate 16 for separating the electrode piece 14.

[0112] The controller 34 of the cutting device 10 is designed to automatically control the cutting device 10 to carry out the cutting method described above. The controller 34 is designed, in particular, as an electronic controller, in particular as a computer unit or computer with a corresponding computer program containing the corresponding instructions.

[0113] The cutting process is particularly carried out as a sub-process in the large-scale production of high-voltage batteries for electric vehicles. The cutting device 10 preferably forms part of a corresponding manufacturing system. For further details, please refer to reference [1].

[0114] In order to improve the separation of electrode pieces for large-scale production of battery cells for electric vehicles or the like, a cutting method and a cutting device (10) are described in which, while an electrode substrate (16) is being conveyed through a cutting device (12), at least one conductor tab (20) is cut free from a conductor strip of an electrode substrate (16). A section (26) of unnecessary material of the conductor strip (24) is created after the conductor tab (20), as seen in a conveying direction (68). The electrode pieces (14) provided with the cut-free conductor tab (20) are then separated by cutting through the electrode substrate (16), including the active material (18), and also the section (26) cut out in step b). This reduces the size of the section (26) and allows it to be removed more reliably from the cutting device (12). List of reference symbols:

[0115] 10 Cutting device 12 Cutting device 14 Electrode piece 16 Web-shaped electrode substrate 18 Active material 20 Conductor lug 22 Active material area 24 Conductor strip 26 Section 26-1 First section 26-2 Second section 28 Section part 30 Conveyor device 32 Section removal device 34 Control system 36-1 First working area 36-2 Second working area 38 Vacuum roller 40 Rotary drive 42 Rotary axis 44 Suction device 46 Circumferential surface 48 Suction opening 50 Cassettes 52-1 First cutting unit 52-2 Second cutting unit 54 Cutting beam generation device 56 Cutting beam deflection device 58 Overlap area 60 Cutting curve 60b1 Cutting curve for free cut by first cutting unit 60b2 Cutting curve for free cut by second cutting unit 60c1 Cutting curve for separating cut by first cutting unit 60c2Cutting curve for separating cut by second cutting unit 60.1Cutting curve first partial cut (front cutting curve) 60.2Cutting curve second partial cut (rear cutting curve) 60.3Cutting curve third partial cut (middle cutting curve) 60.4Cutting curve fourth partial cut (separating cut for cutting through, transverse cut) 62Extraction 64Jet entry point 66Jet exit point 68Conveying direction (material flow) 70Jump 70-1Jump path first cutting unit 70-2Jump path second cutting unit 72Corner area.

Claims

1. A cutting method to be carried out in the course of a series production of cell composites of batteries for singulating electrode pieces (14) from a web-like electrode substrate (16) using cutting means (12), so as to obtain electrode pieces (14) with a flat active material (18) and a lateral arrester tab (20), comprising the steps of: a) providing the web-like electrode substrate (16), which has an active material region (22) and an arrester strip on at least one side of the active material region (22), by conveying the web-like electrode substrate (16) to the cutting means (12); b) cutting at least one arrester tab (20) free from the arrester strip, a portion (26) of unneeded material of the arrester strip (24) being produced before and / or after the arrester tab (20) in the conveying direction (68), characterized by c) singulating the electrode piece (14) provided with the arrester tab (20) cut free by cutting through the electrode substrate (16) inclusive of the active material (18) and also portion (26) cut out in step b), so that portion (26), by being cut through, is reduced in size and decomposed into several portion parts (28), and d) removing the portion parts (28) from the cutting means (12).

2. Cutting method according to claim 1, characterized in that step a) comprises at least the step of: a1) conveying the electrode substrate (16) through two successive and / or overlapping working regions (36-1, 36-2) of a first cutting unit (52-1) and a second cutting unit (52-2) of the cutting means (12); and in that in step b) a first portion (26, 26-1) located before the arrester tab (20) in the conveying direction is cut out by means of the first cutting unit (52-1) and, simultaneously, synchronously or with a time overlap, a second portion (26, 26-2) located behind that arrester tab (20) in the conveying direction is cut out by means of the second cutting unit (52-2), and / or that in step c) a front transection (60c1), viewed in the conveying direction (68), is made by means of the first cutting unit (52-1) and, simultaneously, synchronously or at least with a time overlap, a rear transection (60c2), viewed in the conveying direction (68), is made by means of the second cutting unit (52-2).

3. Cutting method according to any one of the preceding claims, characterized by 3.1 generating at least one cutting beam, in particular a laser beam, and 3.2 directing the at least one cutting beam along cutting curves (60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4) in order to carry out steps b) and c).

4. Cutting method according to claim 3, characterized in that step b) comprises at least one or more of the steps: b1) directing the at least one cutting beam along a front cutting curve (60.1) which extends from a beam entry point (64) in the interior of a region of the arrester strip (24) forming the later unneeded portion (26) to a front corner region (72) between an arrester tab (20) which is at the front with respect to the conveying direction and the active material (18) of the electrode piece (14) and then extends outwards from the front corner region (72) in a direction transverse to the conveying direction (68), in order to separate the front arrester tab (20) from the remaining unneeded portion (26) of the arrester strip (24); b2) directing the at least one cutting beam along a rear cutting curve (60.2) which extends from a beam entry point (64) in the interior of the region of the arrester strip (24) forming the later unneeded portion (26) to a rear corner region (72) between an arrester tab (20) which is at the rear with respect to the conveying direction (68) and the active material (18) of the electrode piece (14) and then extends outwards from the rear corner region (72) in a direction transverse to the conveying direction (68) to separate the rear arrester tab (20) from the remaining unneeded portion (26) of the arrester strip (24); b3) directing the cutting beam along a middle cutting curve (60.3) which extends from the interior of the portion (26) to a corner region (72) between a first arrester tab (20) and the active material (18) of the electrode piece (14), then extends in or against the conveying direction (68) to create an end edge of the active material (18) of the electrode piece (14) between the first arrester tab (20) and a second arrester tab (20) adjacent to the first, and extends from the corner region (72) between the second arrester tab (20) and the active material (18) into the interior of the portion (26) and ends there.

5. Cutting method according to any one of claims 3 or 4, characterized in that step c) comprises: c1) directing the at least one cutting beam along a singulation cutting curve (60.4) which extends from outside the arrester strip (24) through portion (26) transversely through the electrode substrate (16) for singulating the electrode piece (14).

6. Cutting method according to claims 4 and 5, characterized by at least one or more of the following features: 6.1 that the cutting beam successively traverses the cutting curves (60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4), preferably with switching off or fading out at the jump (70-1, 70-2) from cutting curve to cutting curve, 6.2 that the middle cutting curve (60.3) is traversed after the front and the rear cutting curves (60.1, 60.2); 6.3 that the steps are carried out in the order of b1), b2), b3) and c1).

7. Cutting method according to any one of the preceding claims, characterized in that d) comprises: blowing off and / or extracting the portion parts (28).

8. Cutting device (10) for cutting out and cutting off electrode pieces (14) from a web-like electrode substrate (16) in order to obtain electrode pieces (14) with flat active material (18) and a lateral arrester tab (20) for a series production of cell composites of batteries, the cutting device (10) comprising: cutting means (12), conveyor means (30) for conveying a web-like electrode substrate (16) having an active material region (22) and an arrester strip (24) on at least one side of the active material region (22) through a working region (36-1, 36-2) of the cutting means (12), cut portion removal means (32) for removing unneeded portions (26) produced during cutting, and a control system (34) configured to cause the cutting means (12) to cut at least one arrester tab (20) free from the arrester strip (24), wherein after the arrester tab (20) in the conveying direction (68) a portion (26) of unneeded material of the arrester strip (24) is produced, characterized in that the control system (34) is further configured to carry out a cut (60c1, 60c2, 60.4) both through the electrode piece (14) provided with the arrester tab (20) that has been cut free and also through the cut out portion (26), in order to singulate the electrode piece (14) and to divide the portion (26) into a plurality of portion parts (28) in order to remove these by the cut portion removal means (32).

9. Cutting device (10) according to claim 8, characterized in that the cutting device (12) comprises at least one cutting unit (52-1, 52-2) which comprises cutting beam generating means (54) for generating a cutting beam, in particular a laser, and cutting beam deflection means (56), wherein the control system (34) is configured to cause the cutting unit (52-1, 52-2) to move the cutting beam along one or more predetermined cutting curves (60, 60b1, 60b2, 60c1, 60c2, 60.1, 60.2, 60.3, 60.4) over the electrode substrate (16) conveyed by the conveyor (30).

10. Cutting device (10) according to one of claims 8 or 9, characterized in that the cutting means (12) has a first cutting unit (52-1) with a first working region (36- 1) and a second cutting unit (52-2) with a second working region (36-2) which are arranged one behind the other and / or overlapping in the conveying direction (68) of the conveyor means (30), and in that the control system (34) is configured to cause the cutting means (12) to cut out, by means of the first cutting unit (52-1), a first portion (26, 26-1) before the arrester tab (20) in the conveying direction (68) and, simultaneously, synchronously or with a time overlap, to cut out, by means of the second cutting unit (52-2), a second portion (26, 26-2) after that arrester tab (20) in the conveying direction (68), and / or to carry out a front transection (60c1), viewed in the conveying direction (68), by means of the first cutting unit (52-1) and, simultaneously, synchronously or at least with an overlap in time, to carry out a rear transection (60c2), viewed in the conveying direction (68), by means of the second cutting unit (52-2).

11. Cutting device (10) according to claim 9 or 10, characterized in that the control system (34) is configured to cause the cutting beam deflection means (56) b1) to traverse, with the cutting beam, a front cutting curve (60.1) that extends from a beam entry point (64) in the interior of a region of the arrester strip (24) which forms the later unneeded portion (26) to a front corner region (72) between an arrester tab (20) which is at the front with respect to the conveying direction (68) and the active material (18) of the electrode piece (14) and then extends outwards from the front corner region (72) in a direction transverse to the conveying direction (68), in order to separate the front arrester tab (20) from the remaining unneeded portion (26) of the arrester strip (24); and / or b2) to traverse, with the cutting beam, a rear cutting curve (60.2) that extends from a beam entry point (64) in the interior of the region of the arrester strip (24) forming the later unneeded portion (26) to a rear corner region (72) between a rear arrester tab (20) and the active material (18) of the electrode piece (14) and then extends outwards from the rear corner region (72) in a direction transverse to the conveying direction (68), in order to separate the rear arrester tab (20) from the remaining unneeded portion (26) of the arrester strip (24); and / or b3) to traverse, with the cutting beam, a middle cutting curve (60.3) that extends from the interior of the portion (26) to a corner region (72) between a first arrester tab (20) and the active material (18) of the electrode piece (14), then in or against the conveying direction (68) to create an end edge of the active material (18) of the electrode piece (14) between the first arrester tab (20) and a second arrester tab (20) adjacent to the first, and from the corner region (72) between the second arrester tab (20) and the active material (18) into the interior of the portion (26) and ends there.

12. Cutting device according to any one of claims 9 to 11, characterized in that the control system (34) is configured to cause the cutting beam deflection means to c1) traverse, with the cutting beam, a singulation cutting curve (60c1, 60c2, 60.4) that extends from outside the arrester strip (24) through the portion (26) transversely through the electrode substrate (16) for the purpose of singulating the electrode piece (14).

13. Cutting device (10) according to any one of claims 8 to 12, characterized in that the control system (34) is configured to cause the cutting means (12), the conveyor means (30) and the cut portion removal means (32) to carry out the cutting method according to any one of claims 1 to 7.

14. Computer program containing instructions that cause a cutting device (10) according to any one of claims 8 to 13 to carry out the cutting method according to any one of claims 1 to 7.

15. Use of the cutting method according to any one of claims 1 to 7, the cutting device (10) according to any one of claims 8 to 14 or the computer program according to claim 14 in a series production of cell composites of batteries, in particular for electric vehicles.