PRESSURE SYSTEM, LASER JOINING SYSTEM AND PROCESS

Description

[0001] The invention relates to a pressing system for a laser joining system for pressing a base plate and a storage cell together in the region of a joining point for producing an energy storage device, a corresponding laser joining system and the manufacturing method.

[0002] When joining parts using laser joining, fixtures for pressing the parts together are typically used. This is particularly relevant in the production of energy storage devices.

[0003] Modern energy storage systems consist of a multitude of storage cells arranged on a common base plate and joined to it at joints, particularly by laser welding. A base plate in this sense can be, for example, printed circuit boards or connection plates for forming one of the poles (positive or negative pole) or a measuring point of the energy storage system, so that an energy storage system can also have several such base plates.

[0004] For laser joining, the storage cell and the base plate must first be positioned at a joint on the base plate. The two parts are then pressed together and laser-joined, for example, laser-welded, at the joint.

[0005] The clamping system used for pressing is typically designed as a plate or mask with spring elements for each joint. For this purpose, the mask is usually individually tailored or manufactured to fit the respective parts to be joined.

[0006] The mask is pressed onto the base plate, whereby the respective memory cells are pressed onto the base plate at all or at least at a large number of joints.

[0007] As soon as all the parts to be joined are pressed against the respective counterpart or the base plate, the parts to be joined are joined together one after the other at the respective joining points.

[0008] One disadvantage is that such a pressing system requires a mask individually tailored to the respective joining task. Another problem is that with a large number of joining points, such as several hundred or thousand, as in the case of high-performance energy storage devices, the required contact force with which the mask must be pressed against the parts increases linearly with the number of joining points. Furthermore, the contact pressure at the joining points can only be quality assured as a whole. Faulty contact pressures, such as gap spacing due to height differences within the manufacturing tolerances of storage cells, can only be monitored or corrected to a very limited extent.

[0009] DE 20 2009 008 851 U1 discloses a clamping system for pressing together sheets to be welded. Two sheets to be joined are pressed together by two opposing, retractable and extendable clamping elements.

[0010] US 2007 / 0221637 A1 discloses the method of securing two metal plates to be joined using a pressure wheel. The pressure wheel can be lifted off the metal plates or lowered onto them.

[0011] A device for securing the terminals of an integrated semiconductor to a laser beam during bonding is known from US Pat. No. 5,194,710. The device has a vertically oriented recess along which a welding laser beam reaches the desired welding point. In particular, the device also masks the remaining semiconductor from reflected light from the welding laser beam.

[0012] Furthermore, a rotatable pressing element for pressing two metal plates to be joined together during laser welding is known from WO 2011 / 133278 A2.

[0013] A pressing element for pressing body parts together, particularly with a vertical offset, during laser welding is known from US 2005 / 0230363 A1. The pressing element can be moved perpendicular to the body parts by means of actuators. The body parts can be clamped between the pressing element and opposing counterholders.

[0014] The object of the present invention is to improve the joining of a base plate and a storage cell by means of a pressing system, a laser joining system and a method for producing an electricity storage device. The object is achieved by a pressing system for a laser joining system for pressing a base plate and a storage cell together according to patent claim 1.

[0015] This makes it possible to press the base plate and the storage cell together only locally in the area of the joint. The invention takes advantage of the knowledge that the joining process generally determines the speed of the overall process and therefore initially the base plate and the storage cell only need to be pressed together at the respective joint. This creates a previously unused waiting time during joining at one joint, during which processing can be prepared at another joint. It is also possible to use a pressing element that is much smaller and has a lower mass, since unlike in the prior art, pressing is carried out over a large area using a plate or mask, but only at specific points.

[0016] Regardless of the number of joining points or the number of base plates and / or storage cells to be joined, only a low total contact force is required. This allows for a simpler mechanical design, thereby realizing cost and performance advantages with the laser joining system according to the invention.

[0017] The holder can be stationary or movable relative to a machine housing or relative to the location of the laser joining system. The holder can in particular be designed as a support, a table or a conveyor belt section. The holder can also be designed as a holder for receiving a type of part to be joined. For example, the holder can be a carrier on which storage cells are arranged in a matrix. A base plate can be placed on the storage cells so that the storage cells can be joined to the base plate at joining points distributed in a matrix. It is understood that the arrangement of the base plates and / or storage cells in the holder can also be based on other criteria, for example such that a maximum number of storage cells can be arranged, in particular next to one another.

[0018] The plane may, for example, run parallel to a side of a base plate and / or memory cell, in particular parallel to a base plate.

[0019] In particular, for joining at a joint, the pressing element can be moved relative to the holder by means of the parallel positioning device, parallel to a plane formed by the base plate, towards the joint. Using the inclined positioning device, the pressing element can then be moved relative to the holder, for example, transversely, in particular perpendicularly, to the plane. This allows the pressing element to press against the base plate at the joint and thus press a storage cell located beneath the base plate against the base plate until both parts are in gap-free contact. Subsequently, both parts can be joined together using a joining laser. The inclined positioning device is designed to press the parts together during the joining process.

[0020] According to the invention, the two pressure elements can be moved independently of each other.

[0021] A first pressing element can press two parts to be joined together at a first joining point, while a second pressing element is moved to a second joining point. This means that the next joining point can be approached while the joining process is already taking place at the first joining point. A particularly advantageous feature is that the focus of the joining laser can generally be moved much faster, for example using a scanner unit, than a (mechanical) pressing element. However, the joining process itself takes a comparatively long time. This means that a pressing element can be moved parallel to the plane relative to the holder at a comparatively low speed using the parallel positioning device. Idle times or interruptions in the joining process due to changing joining points can be avoided or reduced to a minimum.

[0022] The pressure system can be used according to patent claim 2. In particular, the scissor mechanism can be designed using a scissor linkage and a linear drive. The scissor mechanism can reduce the required installation space and achieve good accessibility, in particular a relatively free arrangement of a joining laser of the laser joining system. The scissor mechanism can also be controlled from one side of the laser joining system.

[0023] The inclined positioning device can have a linear drive and / or a pneumatic drive. It can also comprise an electric and / or magnetic drive. In particular, a pneumatic drive, such as a pneumatic cylinder, allows the relative positioning of the pressure element and the holder to be achieved with particularly low mass and thus low inertia.

[0024] It is also conceivable to use the pressure system according to patent claim 3. For example, the pressure force can be determined by means of the pressure element.

[0025] If storage cells have different dimensions due to manufacturing tolerances, for example, the pressure element can be displaced relative to the holder until a minimum pressure force is registered by a force sensor. This provides a particularly simple way to ensure that both parts are pressed together largely or completely gap-free.

[0026] The sensor can be designed as a separate sensor. It is also conceivable to form the sensor by a sensor system, in particular an integrated one. For example, the sensor can be formed by a device configured to evaluate, for example, position information, a motor current, a control deviation from a previously recorded measured value, or the like, preferably from a positioning system, in particular a parallel and / or inclined positioning device.

[0027] It is particularly advantageous to evaluate a force-displacement curve. This allows, for example, the occurrence of a jump in the measured force to determine whether one of the joining parts or one of the surfaces is deformed and / or whether the joining part is contacting the other joining part.

[0028] It is also conceivable to use the pressure system according to patent claim 4. Then, an area around the joint on the base plate can be cooled during joining.

[0029] A particularly advantageous pressing system is achieved when at least one pressing element has a gripper, preferably for gripping a component, for example, an individual element. This makes it possible, for example, to arrange storage cells one after the other on the base plate, while other storage cells are arranged with the base plate at the respective joining point.

[0030] It is also conceivable to use the pressure system according to claim 5. For example, the pressure element can be annular or cylindrical. This allows, for example, the joining laser beam to pass through the pressure element and thus to join the parts to be joined together through the pressure element.

[0031] The invention further relates to a laser joining system according to claim 6.

[0032] This makes it possible to manufacture a power storage unit from its individual components at a particularly low cost. The laser joining system is also capable of producing different types of power storage units with minimal setup effort.

[0033] It is conceivable to use the laser joining system according to patent claim 7.

[0034] If the beam range of the joining laser is smaller than the working range of the laser joining system, the joining laser can be moved within the working range using a movable beam positioning system. A scanner for controlling the joining laser beam also enables very rapid deflection of the joining laser beam. Furthermore, a scanner enables a wide beam range.

[0035] A possible use of the laser joining system according to patent claim 8 is conceivable. The focus position can be adjusted using a focus position adjustment device. This provides an additional adjustment option that can be used to optimize the joining process.

[0036] Furthermore, the scope of the invention also includes a method for joining a base plate and a storage cell in the region of a joint for producing a power storage device according to claim 9.

[0037] The pressing element and the holder are positioned relative to each other in such a way that the pressing element is located in an area of the base plate arranged on or in the holder and the storage cell in which they are to be joined.

[0038] This process allows a base plate and a storage cell to be pressed together locally in the joint area and joined together at the joint. Since the base plate and the storage cell are only pressed together locally, this results in a particularly simple and cost-effective joining process.

[0039] In this context, "local pressing together" means that the base plate and the storage cell are pressed together only in the area of the joint, in particular by means of a positioning system, preferably an inclined positioning device and a pressing element.

[0040] In particular, if several similar joining parts, such as storage cells, are pressed against another joining part, such as a base plate, "local pressing together" means that not all joining parts are pressed against the other joining part simultaneously. In relation to the production of a power storage device, this means that not all or a majority of the storage cells are pressed against the base plate simultaneously.

[0041] A method according to the invention results when a second pressing element and the receptacle are positioned relative to a second joint to be subsequently processed, while a first pressing element and the receptacle are positioned relative to a first joining point, and / or a base plate and a storage cell are locally pressed together at the first joining point, and / or a base plate and a storage cell are joined at the first joining point.

[0042] In other words, while processing is taking place or being prepared by the first pressing element at the first joint, processing of the second joint can already be prepared.

[0043] The second pressing element is intended to be placed in the area of the second joint, so that a base plate and a storage cell can then be pressed together and joined there. This allows for significant time savings.

[0044] In particular, it can be provided that a beam area of a joining laser beam of the joining laser is shifted in steps parallel to the plane of the pressure system relative to the first joining point. The beam area of the joining laser beam is often smaller than the working area of the laser joining system as a whole. Within the beam area, the focus of the joining laser beam can be shifted parallel to the plane at very high speed. For example, this shift can be achieved using a scanner, which generally operates very fast.

[0045] For example, joining can occur at the first joint. If the second joint is also within the beam area, after the joining process at the first joint is completed, the laser beam can be moved at very high speed to the second joint for joining the base plate and storage cell there. This allows, for example, joints located within a beam area to be processed very quickly one after the other without having to relocate the beam area. Only a "pacing" of the individual joints using a pressure element or an alternating "pacing" of several pressure elements using the corresponding parallel positioning devices is required.

[0046] Once a blasting area has been processed, the blasting area can be shifted in steps so that joints located in the new blasting area can also be processed at high speed.

[0047] It can also be provided that the beam area is continuously displaced, at least temporarily, parallel to the plane relative to the first joining point. For example, it can be provided that the holder is displaced relative to the laser joining system. If, for example, the holder is designed as a conveyor belt, the conveyor belt can be moved continuously (slowly). Within the beam area, this relative movement can be compensated, for example, by appropriately counteracting the joining laser beam using the scanner and / or the pressure element. This allows even particularly large joining parts, such as particularly large base plates of a power storage device, to be processed.

[0048] At least one process parameter, in particular the pressing force and / or position along the pressing direction and / or the geometry of at least one base plate and / or a storage cell, can be detected by means of a sensor arranged on a pressing element and / or by means of the pressing element itself. In particular, the joining process can be monitored and / or enabled or disabled using the process parameter.

[0049] For example, the pressure element can be used as a tactile sensor. This allows the position of a base plate and / or its external geometry in the area of the joining point to be detected. This eliminates the need for a strip image processing unit, for example. If the pressure element has a force sensor, the reaction to the pressure force can be used to monitor, for example, whether the base plate and the storage cell are pressed together without a gap, or whether the pressure force needs to be increased further before the joining process can be released or started.

[0050] The focus position of the joining laser beam can also be controlled depending on the process parameter. For example, the surface position of the joining point can be determined as a process parameter based on the position of the pressure point of the pressure element. The focus position can then be adjusted to this position, for example, for the joining laser penetration.

[0051] It is particularly advantageous if the focus position is shifted obliquely, especially transversely, to the plane, while the joining laser beam is shifted parallel to the plane relative to the first joining point. This is based on the idea that the focus position can often only be shifted at a comparatively low speed. In particular, the penetration depth of the joining laser beam into the base plate or the storage cell—in other words, the "height position"—can often only be changed slowly. However, it has been shown that laser joining can usually be performed with high quality even with a rough adjustment of the focus position.

[0052] Thus, the joining laser beam can "immerse" itself at the first joining point, joining the base plate and storage cell there, and then, while "emerging" from the base plate or storage cell, be redirected to the next joining point in order to "immerse" itself again into a base plate or storage cell without any loss of time.

[0053] Further features and advantages of the invention will become apparent from the following detailed description of variants of the method according to the invention, as well as from exemplary embodiments of a laser joining system suitable for implementing the method, based on the figures of the drawing, which illustrate details essential to the invention, and from the claims. The individual features can be implemented individually or in combinations in variants of the invention.

[0054] The schematic drawing shows embodiments and variants of the invention, which are explained in more detail in the following description.

[0055] They show: Fig. 1 shows a schematic representation of the laser joining system in plan view; Fig. 2 shows the method according to the invention.

[0056] The structure and functioning of a laser joining system and the method according to the invention will be explained in more detail using the example of the production of an electricity storage device.

[0057] The Fig. 1 a laser joining system 1 with a storage cell 2 which is to be laser joined, in particular laser welded, to a base plate 3.

[0058] The laser joining system 1 has a holder 4. The base plate 3 is located in the holder 4 and underneath (in the top view of the Fig. 1The storage cell 2 is arranged at a first joint 5 (not visible and therefore only shown in dashed lines). It is understood that a plurality of storage cells are arranged at a plurality of joints beneath the base plate 3 to achieve a high storage capacity of the power storage device and are intended to be connected to the base plate 3. In particular, a second joint 5a and a third joint 5b are shown as examples.

[0059] The laser joining system 1 comprises a pressing system 6. The pressing system 6 comprises two pressing elements 7, 7'. Each of the pressing elements 7, 7' is guided by a parallel positioning device 8, 8' and an inclined positioning device 9, 9'.

[0060] It can also be seen that a joining laser 10 can be moved along a laser guide rail 11 within the laser joining system 1.

[0061] In an alternative embodiment, the joining laser 10 can be displaced in both a longitudinal and a transverse direction by means of an at least two-dimensional positioning device, in order to thus enable an even wider displacement range.

[0062] The joining laser 10 generates a joining laser beam 12, which is in Fig. 1 shown state is directed towards the first joint 5.

[0063] The parallel positioning devices 8, 8' serve for the relative positioning of the holder 4 and the pressure elements 7 and 7' respectively parallel to the plane E running along the base plate 3.

[0064] Perpendicular to the plane E spanned by the base plate 3, in the Fig. 1 a z-direction is marked.

[0065] The inclined positioning devices 9 and 9' are configured for relative positioning of the pressing elements 7 and 7' and the receptacle 4 at an angle, in particular transversely, to plane E, i.e., along the z-direction. Furthermore, the inclined positioning devices 9, 9' serve to press the joining parts, in particular the base plate 3 and the storage cell 2, together during the joining process.

[0066] Each of the parallel positioning devices 8, 8' has guide rails 13, 13'. Linear drives 14, 14', 14", 14‴ are movably mounted on the guide rails 13, 13'. The guide rails 13, 13', together with the linear drives 14, 14', 14", 14‴, form linear motors that control the scissor mechanisms 15, 15'.

[0067] The guide rails 13, 13' are arranged on both sides of the holder 4. This makes it possible to move the pressure elements 7, 7' to the side so far that the area of the holder is unhindered and accessible from above, so that the parts to be joined can be positioned or removed from the holder 4, for example, using a gripper.

[0068] The inclined positioning devices 9, 9' are arranged at the joints of the scissor mechanisms 15, 15'. The inclined positioning devices 9, 9' are each designed as pneumatic cylinders. The pneumatic cylinders can be used to displace the pressure elements 7, 7' along the z-direction. In particular, the pressure elements 7, 7' can be pressed against the base plate 3.

[0069] Thus, the base plate 3 and the memory cell 2 can be Fig. 1In the state shown of the laser joining system 1, the workpieces are pressed together locally at the first joining point 5 by means of the pressing element 7 by actuating the pneumatic cylinder.

[0070] The position of the pressure element 7 or 7' can be determined by a position sensor of the inclined positioning device 9 or 9'.

[0071] Furthermore, the joining laser 10 has a scanner for controlling the joining laser beam 12. The scanner serves to quickly deflect the joining laser beam 12 within the beam range 16. Thus, if the joining laser 10 is moved along its laser guide rail 11, the beam range 16 is also moved. Thus, the beam range 16 can cover the working area 17 of the laser joining system 1.

[0072] Furthermore, the joining laser 10 has a focus position adjustment device. The focus position adjustment device serves to adjust the focus position of the joining laser beam 12.

[0073] Furthermore, the pressure elements 7, 7' also have temperature control elements. The temperature control elements are designed, in particular, as cooling elements. They serve to cool the surrounding area around a joint 5, 5a, 5b during laser joining by means of the pressure elements 7, 7'.

[0074] The contact area or pressure point of the pressure elements 7, 7' is ring-shaped, so that a passage area is created through which the joining laser beam 12 can pass.

[0075] The Fig. 2 shows schematically the inventive method for joining parts.

[0076] Based on the Fig. 2 and based on the case study of joining the base plate 3 with the storage cell 2 or a plurality of similar storage cells 2, the method is explained in more detail below using the laser joining system 1.

[0077] In a first step 101, the parts to be joined are accommodated in the holder 4 of the pressure system 6 of the laser joining system 1. For this purpose, the storage cells 2 are first arranged next to one another in a matrix within the holder 4. Subsequently, the base plate 3 is placed on the storage cells 2 and held in the holder 4 by means of a holding device of the holder 4.

[0078] In a second method step 102, the pressing element 7 and the receptacle 4 are positioned relative to the first joining point 5 by means of the parallel positioning device 8. This is done in particular by displacing the linear drives 14, 14', by means of which the scissor mechanism 15 and thus the inclined positioning device 9 and the pressing element 7 are displaced within the working area 17.

[0079] The one in the Fig. 1The state shown corresponds to the final state of this process step. It can be seen that the pressure element 7 is positioned above the first joint 5 in the z-direction.

[0080] In a subsequent method step 103, the parts to be joined, i.e., the base plate 3 and the storage cell 2, which are arranged in the region of the first joining point 5, are locally pressed together. For this purpose, the inclined positioning device 9 is actuated, and the pressing element 7 is moved in the z-direction toward the base plate 3 until it presses the base plate 3 against the storage cell 2. Depending on the tolerance or dimension of the storage cell 2, the pressing element 7 must be moved more or less in the z-direction. The end position of the pressing element 7 and thus the position of the first joining point 5 under pressure are detected by the position sensor of the pressing element 7.

[0081] Using the position sensor information, the movement is monitored and adjusted if necessary.

[0082] In the subsequent process step 104, the storage cell 2 is joined to the base plate 3 at the first joining point using the joining laser beam 12. To improve the joining result, the focus position of the joining laser beam 12 is adjusted to the detected position.

[0083] The second pressing element 7' is already located in the area of the second joint 5a.

[0084] According to the method, during the remaining time while the first joining point 5 is being processed, the pressing element 7' is lowered in the z-direction at the second joining point 5a in order to locally press the base plate 3 against the storage cell located below it. Thus, the joining laser beam 12 can be directed to the second joining point 5a immediately after completion of the joining at the first joining point 5 in order to join the two parts together there.

[0085] As soon as the joining laser beam 12 is used to join the second joining point 5a, the first pressure element 7 is raised again in the opposite direction to the z-direction and moved to the third joining point 5b by the parallel positioning device 8. Thus, the joining time at the second joining point 5a is used to move the first pressure element 7 to the third joining point 5b.

[0086] Thus, the joining parts are joined one after the other at the joining points within the beam area 16 by using the pressing elements 7, 7' to approach the joining points one after the other and at these the respective joining parts are only pressed together locally.

[0087] A predefined pattern or a predefined sequence of joints can be traversed. In particular, this variant of the method provides for approaching the joints row by row, i.e., perpendicular to the laser guide rail 11. In another variant, the joints are approached column by column or along a wavy line.

[0088] As soon as all joining points within the beam area 16 have been completely processed, the joining laser 10 is moved along the laser guide rail 11 and thus the beam area 16 in order to enable processing at further, previously unprocessed, joining points.

[0089] In an alternative process variant, the processing also includes other processing methods, for example other laser-based processes such as marking or cutting by the (joining) laser, even outside of joining points, as well as, for example, mechanical processing, in particular deformations, by pressing elements, especially in the time phases in which these are not located in the area of the current joining point.

[0090] In a further variant of the method, the holder 4 is designed as a conveyor belt. In this variant, the conveyor belt and thus the joining elements 2, 3 are continuously displaced parallel to plane E. This displacement is compensated for by the scanner of the joining laser 10 so that the joining laser 10 remains stationary relative to the respective joining point during the joining process. In this variant, the speed of movement of the holder 4 is selected such that at least all joining points can be processed in the transverse direction to the joining laser 10.

[0091] This results in a method for joining parts to be joined in the region of a joint by means of the laser joining system according to the invention, with which parts to be joined together with minimal loss of time and thus particularly cost-effectively and efficiently, in particular a power storage device can be manufactured from a plurality of storage cells and a base plate. List of reference symbols:

[0092] 1 Laser joining system 2 Storage cell 3 Base plate 4 Mount 5 First joining point 5 Second joining point 5 Third joining point 6 Pressing system 7, 7' Pressing element 8, 8' Parallel positioning device 9, 9' Inclined positioning device 10 Joining laser 11 Laser guide rail 12 Joining laser beam 13, 13' Guide rail 13a, 13a', 13a", 13a' Linear drive 15, 15' Scissor mechanism 16 Beam area 17 Working area

Claims

1. Pressing system (6) for a laser joining system (1) for pressing a base plate (3) and a storage cell (2) together in the region of a joining point (5, 5a, 5b) in order to produce a power storage means, comprising - a receptacle (4) for accomodating the base plate (3) and the storage cell (2), - a pressing element (7, 7') for locally pressing the base plate (3) and the storage cell (2) together in the region of the joining point (5, 5a, 5b), - a positioning system for the relative positioning of the pressing element (7, 7') and the receptacle (4) and for pressing the base plate (3) and the storage cell (2) together during the joining process, having • a parallel positioning device (8, 8') for the relative positioning of the receptacle (4) and the pressing element (7, 7') in parallel with a plane (E) and • an oblique positioning device (9, 9') for the relative positioning of the pressing element (7, 7') and the receptacle (4) obliquely, in particular transversely, to the plane (E) and for pressing the base plate (3) and the storage cell (2) together during the joining process, - the pressing system (6) having at least two pressing elements (7, 7') and at least two oblique positioning devices (9, 9'), characterized in that the pressing system (6) has at least two parallel positioning devices (8, 8') and the pressing system (6) is configured to press the base plate (3) and the storage cell (2) together at a first joining point (5, 5a, 5b) using a first pressing element (7, 7'), while a second pressing element (7, 7') is displaced to a second joining point (5, 5a, 5b) so that parts to be joined can then be pressed together and joined there.

2. Pressing system according to claim 1, wherein at least one parallel positioning device (8, 8') has a scissor mechanism (15, 15') and / or a linear drive (13a, 13a', 13a", 13aʺʺ).

3. Pressing system according to either of the preceding claims, wherein at least one pressing element (7, 7') has a sensor, in particular a position sensor for locating a joining point (5, 5a, 5b), a temperature sensor and / or a force sensor for measuring the pressing force.

4. Pressing system according to any of the preceding claims, wherein at least one pressing element (7, 7') has a temperature-control element, preferably for controlling the temperature of at least one region of the joining point (5, 5a, 5b).

5. Pressing system according to any of the preceding claims, wherein at least one pressing element (7, 7') has a passage region for the passage of a joining laser beam.

6. Laser joining system (1) for joining a base plate (3) and a storage cell (2) in the region of a joining point (5, 5a, 5b) in order to produce a power storage means, wherein the laser joining system (1) comprises - a joining laser (10) generating a joining laser beam (12) and - a pressing system (6) according to any of the preceding claims.

7. Laser joining system according to claim 6, wherein a beam positioning system of the joining laser (10) is movable, in particular in parallel with the plane (E), and / or comprises a scanner for controlling the joining laser beam (12), in particular in parallel with the plane (E).

8. Laser joining system according to one of claims 6 or 7, wherein the laser joining system (1) has a focus position adjustment device for adjusting the focus position of the joining laser beam (12).

9. Method for joining a base plate (3) and a storage cell (2) in the region of a joining point (5, 5a, 5b) in order to produce a power storage means using a laser joining system (1) according to any of claims 6 to 8, comprising the steps of: a) accommodating the base plate (3) and the storage cell (2) in or on the receptacle (4) of the pressing system (6) of the laser joining system (1); b) relative positioning of the pressing element (7, 7') of the pressing system (6) and the receptacle with respect to the joining point (5, 5a, 5b) by means of the parallel positioning device (8, 8') of the pressing system (6); c) locally pressing the base plate (3) and the storage cell (2) together in the region of the joining point (5, 5a, 5b) by means of the oblique positioning device (9, 9') and the pressing element (7, 7'); d) joining the base plate (3) and the storage cell (2) at the joining point (5, 5a, 5b) by means of the joining laser (12) of the laser joining system (1), e) relative positioning of a second pressing element (7, 7') and the receptacle (4) to a second joining point (5, 5a, 5b) to be subsequently processed, while • a first pressing element (7, 7') and the receptacle (4) are positioned to a first joining point (5, 5a, 5b), and / or • a base plate (3) and a storage cell (2) are locally pressed together at the first joining point (5, 5a, 5b), and / or • a base plate (3) and a storage cell (2) are joined at the first joining point (5, 5a, 5b).

10. Method according to claim 9, characterized in that a beam region (16) of a joining laser beam (12) of the joining laser (10) is displaced in a stepwise manner in parallel with the plane (E) of the pressing system (6) relative to the first joining point (5, 5a, 5b).

11. Method according to one of claims 9 or 10, characterized in that the beam region (16) is at least temporarily continuously displaced in parallel with the plane (E) relative to the first joining point (5, 5a, 5b).

12. Method according to any of claims 9 to 11, characterized in that at least one process parameter, in particular pressing force and / or position in the pressing direction (z) and / or geometry of at least one base plate (3) and / or a storage cell (2), is detected by means of a sensor arranged on a pressing element (7, 7') and / or by means of the pressing element (7, 7') itself.

13. Method according to any of claims 9 to 12, characterized in that the focus position is displaced obliquely, in particular transversely, to the plane (E), while the joining laser beam (12) is displaced in parallel with the plane (E) relative to the first joining point (5, 5a, 5b).