Laser assisted disassembly of battery assemblies

Abstract

The invention relates to a laser processing method for use in disassembling a battery assembly (10) having a cell assembly (12) and a battery housing (14) surrounding the cell assembly (12), comprising directing a processing beam comprising at least one laser beam (L) along a processing contour (C) onto a surface of the battery housing (14) facing away from the cell assembly (12), the battery housing (12) is structurally weakened along at least one selected section of the machining contour (C). The invention further relates to a method for opening a battery housing (14) and to a device for carrying out a laser processing method.

Description

Technical Field

[0001] This invention relates to the field of batteries, for example, used to power motors in electric vehicles. More particularly, this invention relates to a technique for opening battery casings by means of laser cutting. Background Technology

[0002] The following is based on Figure 1a The structure of a battery assembly (also known as a battery pack) is described in a simplified manner. Figure 1a A battery assembly 10 is shown, in which a core component is arranged a cell assembly 12 having multiple cell modules 122, each cell module comprising one or more electrically interconnected battery cells (in... Figure 1a (Not shown in the figure). The battery assembly 10 includes additional functional components, such as a controller (also known as a BMS or battery management system), an interface to the power-consuming device, cooling elements, and other functional components, which are omitted from the figures for simplicity. The interior of the battery assembly 10 is shielded from the exterior by a battery housing 14, which in this case consists of two housing shells 142, 144, which are securely connected to each other along a lateral circumferential flange 146 (= connection area) (e.g., by means of screws, rivets, and / or by means of adhesives and / or welded joints).

[0003] In order to reuse its components in a resource-efficient manner after the end of the battery module 10's life cycle, the battery module 10 must be at least partially disassembled or removed. One of the first steps in disassembling or removing the battery module 10 is to remove or at least open the housing 14 to access the core components of the battery module 10—in particular the battery cells contained in the cell assembly 12, which are the valuable active materials of the battery module 10.

[0004] To date, the outer casings 142 and 144 of the housing 14 have typically been disassembled manually. This manual process (which typically requires loosening the bolted flanges and / or adhesive joints (and / or other connections such as riveted connections, welded connections, etc.) between the outer casings 142 and 144) is highly complex and requires the battery cells inside the battery assembly 10 to be fully discharged in order to eliminate the risk of uncontrolled discharge (e.g., electric shock, short circuit, etc.) or thermal runaway of the battery cells during disassembly. Those skilled in the art also refer to this complete discharge as deep discharge of the battery cells. Using (partially) automated screw-tightening techniques or cutting methods to loosen or separate the joints between the outer casings 142 and 144, typically made of aluminum-based or iron-based materials, contributes little to improving the efficiency of battery assembly disassembly.

[0005] The object of this invention is to further improve existing techniques for disassembling battery modules. In particular, the battery module housing should be able to be opened flexibly and efficiently as part of an automated process without damaging the battery cells, regardless of the condition and type of the housing connections. Furthermore, contamination of the battery module's interior should be avoided, if possible. Summary of the Invention

[0006] The fundamental object of this invention is achieved by the subject matter of the independent claims. Further possible embodiments of the invention are described in detail in the dependent claims, the specification, and the drawings. Features, advantages, and possible embodiments set forth in the description relating to one of the subjects of the independent claims, with at least the necessary modifications, shall be considered as corresponding subjects of other independent claims, and features, advantages, and possible embodiments of any possible combination of the subjects of the independent claims, in combination with one or more of the dependent claims, where applicable.

[0007] According to the present invention, a laser processing method is provided for use in disassembling a battery assembly. The battery assembly includes cell assemblies and a battery housing surrounding the cell assemblies. The housing may be constructed, for example, of at least two housing shells, which are securely connected to each other along the outer periphery of the housing (e.g., by screws, rivets, adhesives, and / or welding). In a simple design of the battery assembly, the housing shells may also be referred to as semi-shells. The battery assembly may, for example, have a cell-to-pack battery pack architecture. This means that individual battery cells are directly mounted (e.g., foamed) within the battery pack (= battery assembly). Alternatively, the battery assembly may also have a cell-to-module or module-to-pack architecture, in which multiple battery cells are packaged into a single cell module. If the battery assembly includes multiple cell modules, these cell modules are typically electrically connected to each other to combine the capacity of all battery cells. In addition to the battery pack architectures mentioned above, the battery assembly may also have other battery pack architectures. For example, there are also cell-to-chassis architectures, in which the battery cells are directly integrated into the vehicle structure. In this case, the battery assembly according to the invention can be considered part of the vehicle, and the battery casing can be considered part of the vehicle structure. The casing or casing shell, or at least one of the casing shells, can be made of a metallic material, especially an aluminum-based material (especially 3000 series or 5000 series aluminum) or an iron-based material (especially stainless steel). The thickness of the metallic casing shell can, for example, range from 0.5 mm to 3 mm. Alternatively, at least one of the casing shells can be made of plastic or fiber-reinforced composite material (CFRP). Preferably, the casing shells have the same or similar material composition. Examples of battery components according to this disclosure include various (rechargeable) batteries from the eMobility sector, such as those for automobiles, trucks or commercial vehicles (BEV, PHEV, MHEV or HEV), forklifts, electric bicycles, ships, aircraft, drones, etc.; and various (rechargeable) batteries from other sectors, such as those for building power supply or grid stabilization or power tools (gardening tools, cordless screwdrivers, etc.).

[0008] According to the present invention, a processing beam comprising at least one laser beam is directed along a processing contour onto a surface of the battery casing opposite to the cell assembly, such that at least one selected segment of the battery casing along the processing contour is structurally weakened. In other words, the weakening of the casing structure results in a desired break point in the battery casing along the relevant contour segment. The casing can then be efficiently opened along the desired break point using a subsequent opening method.

[0009] Laser processing methods can preferably be performed using solid-state lasers (especially fiber lasers such as the TruFiber 500 to 2000 series from the applicant) or disk lasers such as the TruDisk 2000 to 8000 series or TruDisk 3001 to 24001 series from the applicant) as single-mode or multimode lasers. The laser power can be, for example, in the range of 500 W to 24 kW, preferably in the range of 2 kW to 8 kW.

[0010] In the laser processing method according to the invention, the battery casing is selectively weakened so that laser radiation from the laser beam used does not propagate into the interior of the battery assembly. In the laser processing method according to the invention, the battery casing is not separated, or at least not completely separated, in the relevant contour sections. Therefore, a material layer is retained at least a portion of the thickness of the battery casing, which blocks the laser beam from entering the interior of the battery assembly. Thus, the processing contour can also extend at the location where the optical axis of the processing laser beam intersects with one or more battery cells or cell modules. In this way, the battery cells are protected from severe damage caused by laser radiation. Simultaneously, the casing is weakened to a degree that allows it to be opened with minimal force in a subsequent opening step.

[0011] The machining profile can extend, in particular, on one of the housing shells, for example, on the first housing shell (i.e., especially the upper housing). This avoids the connection between multiple housing halves when the housing is opened.

[0012] The processing contour may also include contour sections in which the laser processing method is implemented as a laser cutting method (especially laser melting cutting, laser burning cutting, or laser sublimation methods) to create a cutting gap across the entire thickness of the housing. For these contour sections, it should be ensured that the optical axis of the laser beam does not cut the battery module or battery cell. Furthermore, in such "safe" contour sections, internal contamination of the battery may not be severe for subsequent processing and recycling steps. It can be advantageous to create access for opening the housing (e.g., by means of a clamp) in this way, such as a recess or gap directly adjacent to the desired break point.

[0013] The inventors have recognized that the laser processing method according to the invention is suitable for disassembling battery packs. This is not a matter of course, as laser cutting is a thermal processing method, and the workpiece to be processed is partially heated to very high temperatures. In contrast, for the battery cells of a battery pack, a heat input of 60°C, not exceeding 100°C, can be dangerous (ignition risk). It has been shown that laser processing can significantly simplify the process of disassembling battery packs due to its flexible applicability and high degree of automation. First, the disassembly speed is significantly increased compared to manual processes. Furthermore, the process can be performed regardless of the type and / or nature of the connection between the housings (welded connections, screw connections, riveted connections, adhesive connections, etc.) by selectively separating only the outer casing, providing great flexibility. When using the (CNC) laser processing method according to the invention, it is generally not necessary to discharge the battery cells, as the high precision of the method makes it highly likely that serious damage or interference to the battery cells inside the battery pack, which could lead to uncontrolled discharge or thermal runaway, can be eliminated. The laser cutting method is performed in a safe environment and is preferably fully automated. This also reduces the risk of personal injury during the disassembly of the battery assembly.

[0014] According to one variation, the laser processing method is a laser cutting method in which a laser beam, together with a cutting gas jet, is directed along a processing contour onto the surface of the battery casing opposite to the cell assembly. The laser cutting method is preferably configured such that the cutting gap created along the processing contour extends only over a portion of the thickness of the battery casing. Molten material or slag generated during this laser cutting method is blown upwards from the cutting gap by the cutting gas jet (because the bottom of the cutting gap is not open). The cutting depth (i.e., the depth of the cutting gap) is preferably at least 0.1*d, more preferably at least 0.3*d, more preferably at least 0.5*d, and preferably at most 0.9*d, more preferably at most 0.8*d, more preferably at most 0.7*d, where "d" is the thickness of the casing or casing wall at the corresponding location. In this case, the cutting gap can also be referred to as a notch because its bottom is closed. In particular, an inert cutting gas, such as nitrogen, can be used for the laser cutting method. Furthermore, using an inert cutting gas can prevent the risk of ignition from the inside of the battery assembly or surrounding plastic parts (e.g., foam or plastic components) on the battery assembly. Especially in the case of relatively thick metal casings, oxygen or oxygen-containing gas mixtures can also be used as the cutting gas, and therefore the laser cutting method can be implemented as a laser combustion cutting method.

[0015] When the laser processing method is performed as a laser melting method or a laser burning cutting method, the laser cutting method is performed using a laser cutting device, preferably a laser cutting device with fixed optics, by means of which the laser beam and the cutting gas jet are directed (i.e., coaxially) onto the housing via a cutting nozzle. Alternatively, the method can be performed using a laser beam having a central core beam and an annular beam surrounding the core beam. This beam shape can be achieved using a known 2-in-1 technique, in which the laser beam is guided to the processing optics via a 2-in-1 optical fiber, thereby enabling both increased cutting speed and improved cutting edges.

[0016] For example, a nozzle with an inner contour resembling a Laval nozzle can be used as a cutting nozzle. Using a Laval nozzle as a cutting nozzle allows for a relatively large working distance with relatively low cutting gas consumption.

[0017] According to one variation, the cutting gas can also be supplied to the molten pool generated by the laser beam during the cutting process at an angle of less than 90°. The angle of incidence of the cutting gas relative to the shell surface (preferably in the case of perpendicular incidence of the laser beam) can preferably be between 75° and 15°, more preferably between 60° and 30°. Therefore, the molten material generated by the laser beam can be blown out laterally from the cutting gap. This means, for example, better protection of the cutting head from spatter. Generally, contamination from molten material spatter can also be better controlled by deflecting all spatter in one direction.

[0018] Alternatively or otherwise, the following variations are also possible, in which the splashes are extracted by a suction device.

[0019] As an alternative to the laser cutting method described above, the cutting gap can also extend across the entire thickness of the battery casing (i.e., the material thickness), provided that the cutting parameters are set such that molten slag accumulates at the bottom of the cutting gap and seals it off, preventing the laser beam from irradiating the cutting gap that passes through the bottom of the battery casing. Such an incomplete cutting gap can be achieved, for example, by increasing the cutting speed (feed rate) to the extent that the desired incomplete cutting gap is formed, compared to conventional laser cutting methods where molten slag (i.e., the melt discharged during cutting) is completely discharged from the cutting gap.

[0020] According to an alternative variation, the laser processing method can be implemented as a laser cutting method, which is configured such that the cutting gap generated along the processing contour extends only over a portion of the thickness of the battery casing. During laser cutting, molten material generated by the laser beam accumulates laterally on the upper side of the battery casing beside the cutting gap by forming a molten pool, and the molten material solidifies. The formation of the molten pool can be assisted, for example, by electromagnetic and / or pneumatic means. This method differs from the laser cutting method described above in that the molten material is removed in a more controlled manner, thereby preventing uncontrolled contamination of the processing apparatus and / or the battery casing.

[0021] According to another alternative method, the laser processing method can be implemented as a laser sublimation method, wherein the material of the battery casing is at least partially vaporized along the processing contour by means of a laser beam. Furthermore, the laser sublimation method is configured such that the cutting gap generated along the processing contour extends only over a portion of the thickness of the battery casing. In a variation of this method, the depth of the cutting gap or the resulting notch is preferably in the range of 0.1*d to 0.9*d, more preferably in the range of 0.3*d to 0.8*d, and even more preferably in the range of 0.5*d to 0.7*d. Molten material that may be generated during laser sublimation cutting is discharged upwards from the cutting gap by the vapor pressure generated in the cutting gap. In laser sublimation cutting, pulsed laser radiation is preferably used to achieve the required strength for vaporizing the casing material.

[0022] According to an alternative method, the material of the battery casing is heated along a processing contour by a laser beam, causing the material to undergo a structural change over at least a portion of the thickness of the battery casing. This structural change results in structural weakening of the casing wall in the irradiated area. In this variation, gaps or notches are preferably not created in the casing. Instead, the casing material undergoes structural weakening along the processing contour over at least a portion of the casing thickness, for example, by targeted embrittlement of the material (e.g., due to brief heating followed by rapid cooling). In this way, the casing can also be targetedly weakened along the processing contour, allowing the casing to be opened efficiently in a subsequent opening step (e.g., by means of mechanical methods).

[0023] The laser processing method according to the present invention may further include optical observation of the laser processing method to identify the actual trajectory of the modification produced on the housing. Furthermore, if the trajectory of the produced modification deviates from a predetermined processing contour by at least a predetermined minimum value, the method may include readjusting the processing parameters of the laser processing method to make the modification trajectory conform to the predetermined processing contour. By compensating for the detected tolerances, the accuracy of the processing can be improved. Therefore, scrap can be reduced.

[0024] Furthermore, the laser processing method implemented as a laser cutting method may include the following steps: measuring the distance between the cutting nozzle used for the laser cutting method and the surface of the first housing shell during the laser cutting method; and adjusting the preset cutting parameters of the cutting method based on the measured distance. By measuring and, if necessary, adjusting the working distance of the cutting nozzle (e.g., by capacitance, using an OCT measurement method, or by means of laser triangulation), the contour accuracy and thus the precision of the laser cutting can be improved.

[0025] Further features of the laser processing method according to the present invention may include: • Pre-treat the shell to be processed (e.g., cleaning, pre-cooling, pre-heating, etc.) to enhance the desired effect of subsequent laser processing methods and / or improve process reliability; • For example, through OCT (an efficient and precise cutting process that can selectively generate the desired break point), the molten pool can be actively controlled (especially in height profile measurement). • Introduce additives in a targeted manner to generate or maintain the desired breaking point.

[0026] According to the present invention, a method for opening a battery casing, wherein the battery casing houses the cell assembly of a battery pack, is also provided. In a first step, the method includes targeted weakening of the structure of the battery casing along a predetermined processing contour by means of a laser processing method according to any of the variations described above. In a second step, the method includes mechanically separating an opening segment of the battery casing from the peripheral remaining segment of the battery casing along the processing contour. The mechanical separation of the opening segment from the remaining segment can be achieved, for example, by means of an opening device that, for example, clamps the casing in the opening segment by means of one or more suction cups, magnets, grippers, or similar devices, and pulls the opening segment upward relative to the peripheral casing (remaining segment) along a desired break point, as when opening a can. According to another variation, the opening segment can also be pressed downward into the interior of the battery pack, for example, using a vibratory hammer, to disengage the opening segment from the surrounding remaining area, and then the opening segment is removed.

[0027] According to the present invention, a laser processing apparatus for processing the housing of a battery assembly is also provided. The apparatus includes at least: a workpiece support for supporting the battery assembly during the laser processing; a laser beam source for providing a laser beam; a laser processing head for focusing the laser beam toward the battery housing; and a control unit configured to operate the apparatus to perform a laser processing method according to a variation of the above-described modifications. If the laser processing method is implemented as a laser melting cutting method or a laser burning cutting method, the apparatus then further includes at least one corresponding cutting gas supply device. In particular, the apparatus can be designed as a 3D laser cutting device, by means of which the processing head can be guided not only vertically (see 2D laser flat panel device) but also tilted. Attached Figure Description

[0028] The following description of preferred exemplary embodiments is provided to illustrate the invention in more detail with reference to the accompanying drawings.

[0029] In the attached diagram: Figure 1a A schematic top view illustrating a laser cutting method according to the present invention is shown. Figure 1b Schematic illustration based on Figure 1a Cross-sectional view of the battery assembly; Figure 2 This illustration schematically shows the creation of a cutting gap in a battery casing using conventional laser cutting methods; and Figures 3a to 3e A variation of the laser processing method according to the present invention is illustrated schematically.

[0030] In the accompanying drawings, the same elements or elements with the same function are provided with the same reference numerals. Detailed Implementation

[0031] Figure 1a The battery assembly 10 is shown in top view, where the plane of the drawing corresponds to the xy plane of the Cartesian coordinate system. The battery assembly 10 includes a cell assembly 12 having a plurality of cell modules 122, which in turn house a plurality of battery cells (not shown in the drawing). In other words, the depicted battery assembly 10 has a cell-to-module or module-to-pack battery architecture. The cell assembly 10 is connected to other battery components (in...) Figure 1a and Figure 1b(Not shown in the diagram) are surrounded by a housing 14. The housing 14 includes a first housing shell 142 and a second housing shell 144, which are securely connected to each other along a connection area 146 on the outer periphery of the housing 14—here, for example, by means of screws. It goes without saying that other connection types besides screws are possible, such as riveting, adhesive bonding, welding, or combinations of multiple connection types. In the example shown, the first (in this case, the upper) housing shell 142 is modified along a cutting contour C by means of a laser beam to selectively weaken the housing structure along the cutting contour C and create a desired break point. As can be clearly seen in the top view, the cutting contour C (shown here as a closed cutting contour C) extends in multiple contour segments directly above the cell module 122. Since the laser beam L does not penetrate into the interior of the housing during the laser processing method according to the invention, the cell module 122 is not damaged, and the interior of the battery is not contaminated by the laser processing. The opening area (the area within the closed outline C) of the upper housing 142, separated by the desired break point, can then be pulled up like a can or otherwise removed without loosening the screws 148 that are screwed together and without damaging or contaminating the interior of the battery assembly 10.

[0032] Figure 1b It shows according to Figure 1a The section line A–A passes through the cross-section of battery assembly 10. Figure 1b It is also clearly visible that the optical axis of the laser beam L intersects with the battery cell module 122. Figure 1b The laser processing head 20 of the laser processing machine or equipment is shown schematically, by means of which the laser beam L—if necessary, together with the cutting gas jet—is directed onto the first housing shell 142 of the battery housing 14.

[0033] Figure 2 A conventional laser cutting method is schematically illustrated, which can be used to create a cutting gap in the housing 14 of the battery assembly 10. The feed direction (or machining profile C) of the machining beam, consisting of the laser beam L and the cutting gas jet G, extends perpendicular to the drawing plane (as follows). Figures 3a to 3e (Same as in China). According to Figure 2The material of the housing 14 or the first (upper) housing outer shell 142 is melted by means of a laser beam L, and the resulting molten material S is blown downward from the resulting cut seam by means of a cutting gas jet G. Therefore, the resulting cut gap extends over the entire thickness d of the shown local area of ​​the housing wall. According to this disclosure, when the laser cutting method described above is applied to cut the battery housing 14, it should be noted that the downward-flowing cutting slag (or molten material) S penetrates into the interior of the battery assembly and contaminates the interior of the battery assembly. Furthermore, the laser beam L penetrates into the interior of the battery assembly and may damage or destroy internal components of the battery assembly. Figure 2 Similar to laser cutting methods, for non-critical contour sections of contour C, laser sublimation can also be used, for example, in which a cutting gap is created across the entire workpiece thickness (i.e., the shell thickness). In this way, compared to conventional laser cutting methods (see...),... Figure 2 Compared to other materials, contamination inside the shell can be reduced.

[0034] Figures 3a to 3e Variations of the processing method according to the invention for use in disassembling battery assembly 10 are shown schematically.

[0035] Figure 3a A variation is shown in which the laser processing method is implemented as a laser cutting method extending over the entire thickness d of the housing wall, wherein the processing parameters (especially the feed rate and / or laser power) are set such that the molten material S generated during cutting cannot be completely discharged from the cutting gap, but instead accumulates and solidifies at the lower end of the cutting gap. In this way, the cutting gap closes at the bottom, and the laser beam L cannot penetrate downwards into the interior of the battery assembly 10.

[0036] Figure 3b The following laser cutting method is illustrated, in which a laser beam L melts the material of a housing 14 to a predetermined depth, which is less than the thickness d of the housing wall. According to a variation of this method, a cutting gas G is injected into the processing area at an angle relative to the surface of the housing 14 via a transverse nozzle 22 (also called a "sidejet"), causing the molten material S generated by the laser beam L to be blown out in a predetermined direction (here, to the left), thereby forming a cutting gap or notch. It should be understood that, with... Figure 3b A similar variation of the method shown in the diagram can also involve pointing the cutting gas G coaxially with the laser beam L onto the surface of the housing via a common nozzle 20. In this case, the molten material S is discharged upwards from the cutting gap on both sides.

[0037] according to Figure 3cIn the method variation shown, the molten material generated by the laser beam L accumulates on the surface of the shell by forming a molten pool, along the generated cutting gap, or by generating a notch.

[0038] Figure 3d A laser sublimation cutting method is schematically illustrated, in which the cutting gap or notch is generated by a laser beam L, preferably a pulsed laser beam. Here, the material is selectively vaporized by the laser beam L and partially melted if necessary. The molten material S that may form is discharged upward from the cutting gap or notch by the vapor pressure present in the cutting gap.

[0039] at last, Figure 3e A variation of the method is shown in which the material of housing 14 or the first housing outer shell 142 is structurally modified by a laser beam L (and / or by additionally introduced additives) without creating a cutting gap or notch. In this way, the material of housing 14 can also be decisively weakened along the machining contour C to produce the desired fracture point.

[0040] The following list contains the features and processing parameters already mentioned, as well as additional features and processing parameters that may be relevant to the laser cutting method according to the invention for cutting the battery casing 14 of the battery assembly 10: • First housing 142 – preferably two housings 142, 144 – comprise sheets of thickness in the range of 0.5 mm to 3 mm, particularly aluminum-based (3000 series or 5000 series aluminum) or iron-based (especially stainless steel) sheets; • Use a single-mode laser (e.g., TruFiber 500 to 2000 series from the applicant) or a multimode laser (e.g., TruDisk 2000 to 8000 series or 3001 to 24001 series) as a laser beam source for the laser processing method, preferably having a laser power in the range of 2 kW to 8 kW; • Preferably, a laser processing method implemented as a laser cutting method can be performed using a fixed optics device that moves above the workpiece (i.e., the first housing housing 142), utilizing a cutting nozzle, using a cutting gas (conventional laser cutting), and preferably using an inert cutting gas to expel the molten material; • For other applications (e.g., laser sublimation cutting or irradiation without removing material), remote laser processing can also be performed using scanner optics; • The laser beam L used in the laser processing method can have a beam parameter product in the range of 0.38 mm*mrad to 16 mm*mrad, especially up to 0.6 mm*mrad (single mode) or up to 6 mm*mrad (multimode), preferably 4 mm*mrad; • The beam diameter L of the laser beam on the workpiece (i.e., on the surface of the first housing 142) can be in the range of 50 µm to 500 µm, particularly in the range of 30 µm to 70 µm (single mode) and / or (single spot or n-in-1) in the range of 100 µm to 300 µm (multimode). • Preferably, an infrared laser with a wavelength in the range of 800 nm to 1200 nm, especially an infrared laser with a wavelength of 1030 nm or 1070 nm, can be used as the laser for the laser processing method. Alternatively, VIS lasers, especially VIS lasers with a wavelength of 515 nm (green spectral range), can also be used for laser processing methods; • The laser power used in laser processing methods can be in the range of 0.5 kW to 24 kW, and more particularly from 2 kW to 8 kW; • The feed rate of laser processing methods can range from 1 m / min to 80 m / min (depending on the material thickness), especially at least 5 m / min, or at least 10 m / min, or at least 20 m / min, and up to 60 m / min; • As a laser cutting method, cutting optics with a cutting nozzle and cutting gas and an imaging ratio of 1:1 to 5:1, especially 1.5:1 to 2:1, can be used in laser processing methods; • Alternatively, an optical scanner unit with an imaging ratio of 1:1 to 5:1, especially 1.5:1 to 2:1, may be used (e.g., the applicant’s scanner optics designated PFO33-2). • Camera-based sensors (see the applicant's VisionLine products) can be used for position control during laser processing methods; The surface of the housing 14 to be processed can be prepared for the cutting method, for example, by appropriate cleaning methods (e.g., laser cleaning, grinding or other mechanical cleaning, chemical cleaning, etc.). This allows surface contaminants to be removed before the laser processing method, thereby improving the process reliability of the cutting method.

Claims

1. A laser processing method for use in disassembling a battery assembly (10), wherein, The battery assembly (10) has a cell assembly (12) and a battery casing (14) surrounding the cell assembly (12), the method comprising: A processing beam comprising at least one laser beam (L) is directed along a processing profile (C) onto a surface of the battery housing (14) facing away from the cell assembly (12), such that at least one selected segment of the battery housing (12) along the processing profile (C) is structurally weakened.

2. The laser processing method according to claim 1, in, The laser processing method is a laser cutting method, in which the laser beam (L) and the cutting gas jet (G) are directed together along the processing contour (C) onto the surface of the battery casing (14) opposite to the cell assembly (12); and The laser cutting method is configured such that the cutting gap generated along the processing contour (C) extends only on a portion of the thickness (d) of the battery casing (14).

3. The laser processing method according to claim 2, in, The cutting gas (G) is supplied at an angle of less than 90° to the molten pool generated by the laser beam (L) during the cutting process.

4. The laser processing method according to claim 1, in, The laser processing method is a laser cutting method; The laser cutting method is configured such that the cutting gap generated along the processing contour (C) extends only over a portion of the thickness (d) of the battery casing (14); and During laser cutting, the molten material (S) generated by the laser beam (L) accumulates laterally on the upper side of the battery casing (14) beside the cutting gap by forming a molten pool, and the molten material solidifies.

5. The laser processing method according to claim 1, in, The laser processing method is a laser sublimation method, in which the material of the battery casing (14) is at least partially vaporized along the processing contour (C) by means of a laser beam (L); and The laser sublimation method is configured such that the cutting gap generated along the processing contour (C) extends only on a portion of the thickness (d) of the battery casing (14).

6. The laser processing method according to claim 1, in, By means of the laser beam (L) heating the material of the battery housing (14) along the processing contour (C), the material undergoes a structural change in at least a portion of the thickness (d) of the battery housing, the structural change causing a weakening of the housing wall structure in the irradiated area.

7. A method for opening a battery housing (14) that houses a cell assembly (12) of a battery assembly (10), the method comprising: The structure of the battery casing (14) is targetedly weakened along a predetermined processing contour (C) by means of the laser processing method according to any one of claims 1 to 6; The opening section of the battery housing (14) is mechanically separated from the remaining peripheral section of the battery housing (14) along the processing contour (C).

8. A laser processing apparatus for processing the housing (14) of a battery assembly (10), the apparatus comprising at least: Workpiece support for supporting the battery assembly (10) during the laser processing. Laser beam source, used to provide a laser beam (L); A laser processing head (20) is used to focus the laser beam (L) toward the battery casing (14); as well as A control unit configured to operate the device to perform the laser processing method according to any one of claims 1 to 6.

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