Method and system for replacing battery cells in a battery storage system

Abstract

The present invention relates to a method and a system for replacing defective battery cells, comprising a cell shell and a cell interior, in a battery storage device comprising an arrangement of cylindrical battery cells whose longitudinal axes are arranged parallel to each other, comprising the following steps: determining a position of a defective battery cell; removing the defective battery cell or the cell interior of the defective battery cell from the battery storage device in the direction of the longitudinal axis, forming a cylindrical cavity with a circumference; inserting a new battery cell into the cylindrical cavity at the location of the removed battery cell or the removed cell interior.

Description

[0001] The present invention relates to a method and a system for replacing defective battery cells in a battery storage system comprising an arrangement of cylindrical battery cells.

[0002] Battery storage systems, particularly in the area of ​​vehicle batteries, are modular in design. Within a battery module, the individual battery cells are first interconnected, and several modules are electrically connected in parallel to form the battery storage system. The modules are often interchangeable and standardized.

[0003] The advantages of the modular design lie in its ease of maintenance and repair. Defective or aged modules can be easily replaced without having to dismantle the entire battery system. This results in less downtime. Another advantage of the modular design is that the battery storage capacity can be adjusted by adding or removing modules, enabling a wide range of applications thanks to its scalability. Faults can also be easily identified and rectified due to the modular design.

[0004] In the so-called cell-to-pack approach, all battery cells are connected in a single battery pack without forming battery modules. Cell-to-pack battery storage systems are increasingly replacing modular battery storage systems for vehicle batteries, as the cell-to-pack approach offers advantages in terms of efficiency, cost, weight, and space requirements.

[0005] More battery cells can be integrated into the same volume, and the reduced amount of structural materials and housings reduces the overall weight of the battery storage system, which is particularly advantageous in electric vehicles, as less weight leads to higher efficiency and range.

[0006] Furthermore, the cell-to-pack approach enables more efficient cooling, as the cooling system can be positioned closer to the cells. The elimination of additional module housings reduces obstacles to heat flow, resulting in improved heat dissipation.

[0007] The cell-to-pack approach also offers greater structural integrity and safety. Furthermore, the direct integration of battery cells into the battery pack allows for more flexible and innovative designs that can be better adapted to the specific requirements of the vehicle. For example, cell-to-pack battery storage systems can be integrated into the vehicle body.

[0008] However, the cell-to-pack approach currently does not allow for the repair or replacement of individual battery cells. A defect in a single cell during production currently leads to the total failure of the entire battery storage system and the loss of the materials used and the added value up to the current manufacturing stage. At the customer's site, a defective battery cell also leads to the failure of the battery storage system and, since the entire system must be replaced, to high costs.

[0009] Various methods and devices for repairing battery storage systems are known in the prior art.

[0010] Publication KR102426946 A1 describes a method for replacing and recycling defective battery cells in a modular battery storage system of an electric vehicle (EV). The EV battery module can be reused by replacing only the defective battery cells. The method comprises a detection step to identify a defect in a battery cell and its location; a battery storage disconnection step to disconnect the battery storage system from the EV; a battery module disconnection step to remove the battery module containing the defective battery cell; and a battery pack reconnection step to replace the defective battery cell with a new one and reconnect the disconnected components.

[0011] Document EP 3 930 074 B1 discloses a fault handling method for a battery module in which a cover plate of the faulty battery cell is opened, electrolyte is removed from the faulty battery cell through the opening, a conductive component is inserted, and the positive electrode terminal is connected to the negative electrode terminal of the faulty battery cell. A similar method is disclosed in CN112310562B, wherein a defective battery cell is bridged.

[0012] Publication CN 109904544 A describes a device in which battery cells are separated using a laser cutting system and then cleaned of residues with a type of stirring rod. The positive and negative terminals are then removed and the cell contents are pressed out of the casing.

[0013] A disadvantage of the current state of the art has proven to be that no method has yet been provided that allows for the simple repair of a cell-to-pack battery storage system.

[0014] According to the invention, a method for repairing battery cells in a battery storage system according to claim 1, and a system for carrying out the method according to the dependent claim are provided.

[0015] Further advantageous embodiments of the present invention are specified in the dependent claims.

[0016] According to a first aspect, a method for replacing a defective battery cell is provided, comprising a cell shell and a cell interior, in a battery storage device comprising an arrangement of cylindrical battery cells whose longitudinal axes are arranged parallel to each other, comprising the following steps: determining a position of a defective battery cell; removing the defective battery cell or the cell interior of the defective battery cell from the battery storage device in the direction of the longitudinal axis, forming a cylindrical cavity with a circumference; and inserting a new battery cell or a new cell interior into the cylindrical cavity in place of the removed battery cell or cell interior.

[0017] The advantage of this approach, particularly for cell-to-pack battery storage systems, lies in the fact that only the defective battery cells can be selectively removed, while the other intact cells remain in place. This makes repairing a battery storage system without removing battery modules possible in the first place and allows for resource-efficient repair.

[0018] In this process, the battery cell or the cell interior is removed from the battery storage system in the direction of the longitudinal axis and thus the arrangement direction of all battery cells, which is advantageous because the rest of the battery storage system is not affected and a new battery cell or a new cell interior can be inserted again without major effort.

[0019] The cell interior includes, in particular, an electrolyte and a coiled cell.

[0020] According to a further embodiment, the method further comprises the following steps: exposing at least one end face of the defective battery cell in the battery storage system and disconnecting the battery cell contacts.

[0021] It has proven advantageous to expose only the end face of the defective battery cell, as this avoids opening the entire battery pack and damaging the other battery cells. According to the invention, it is further advantageous to disconnect the battery cell contacts before subsequent work steps, both to ensure safe working conditions and to prevent damage to the other battery cells from a short circuit.

[0022] According to another embodiment, it can be provided that the removal of the defective battery cells or the cell interior in the direction of the longitudinal axis is carried out by pressing them out.

[0023] Pressing a battery cell out of a battery storage system offers several advantages, particularly compared to pulling it out. When pressing, the applied force is distributed more evenly, reducing the likelihood of physical damage to the battery cell. With pulling, uneven force distribution, especially from a gripper arm, can lead to damage to the terminals or the battery cell itself. For the same reasons, and because pressing allows for more precise control of the movement due to the rigid plunger, it minimizes the risk of damage to the casing or adjacent battery cells. Pressing can also be designed so that the forces are applied evenly across the entire top or bottom face of the battery cell, thus reducing tension and stress.

[0024] The pressing process can be more easily automated, as it is more controllable and reproducible because the battery cell or the inside of the cell does not need to be gripped.

[0025] Furthermore, it may be provided that, in addition to determining the position of the defective battery cell, the type of defect is also determined, whereby the type of defect indicates whether the battery cell has faulty electrical properties or mechanical damage to the cell shell.

[0026] It has proven advantageous to distinguish between a defect due to faulty electrical properties of the battery cell and a defect due to damage to the cell shell, as these two types of defects are easily distinguishable from each other.

[0027] It has been shown that a defective battery cell in a battery storage system can be detected particularly through voltage, temperature, or current monitoring, since the battery storage system is sealed and visual inspection is not possible. If, in addition, a visual inspection is carried out after exposing at least one end face of the defective battery cell in the battery storage system, any damage to the cell casing can be visually identified.

[0028] According to a further aspect of the invention, in addition to determining the position of the defective battery cell, the type of defect is also determined, the type of defect indicating whether the battery cell has faulty electrical properties or mechanical damage to the cell casing. Likewise, the removal of the defective battery cell or its interior is carried out depending on the type of defect, with the interior being removed in the case of faulty electrical properties and the entire battery cell being removed in the case of damage to the cell casing.

[0029] It has proven advantageous to remove the defective battery cell or its internal components depending on the type of defect, as this allows for targeted and resource-efficient repair. This also helps to preserve the overall functionality of the battery storage system.

[0030] Surprisingly, it has proven advantageous for the integrity and stability of the battery storage system if the cell shell of a battery cell can remain in the storage system and only the cell interior is replaced. In this case, the remaining cell shell prevents the matrix material from crumbling or the remaining battery cells from being pushed into the cavity created by removing the cell interior.

[0031] According to another aspect, it may be provided that in the case of removing the cell interior of the defective battery cell, the following step is included: Opening the cell casing of the defective battery cell at an upper and / or a lower end face in order to remove the cell interior.

[0032] It has proven advantageous to open the upper and / or lower end face of the cell casing before removing the cell interior, as this prevents damage to the cell casing during removal and ensures clean separation surfaces, facilitating the insertion of a new battery cell. However, it is also possible to remove the cell interior together with the upper and / or lower end face of the cell casing, for example, by pushing it out.

[0033] According to a further embodiment, the new battery cell to be used has a circumference that is equal to or smaller than the circumference of the cylindrical cavity.

[0034] Surprisingly, it has turned out that a new battery cell can be inserted both into the cylindrical cavity created by removing the defective battery cell and into one created by removing the cell's interior.

[0035] This is advantageous because, in the event of electrical faults, the battery storage system can be repaired in a targeted and resource-efficient manner while maintaining its integrity and stability. Furthermore, this approach ensures the continued functionality of the battery storage system.

[0036] According to another embodiment, it is provided that the properties of the newly inserted battery cell are further adapted to the cell aging and electrical properties of the other battery cells of the battery storage system.

[0037] It is advantageous if the cell aging and properties of a new battery cell are adapted to those of the other battery cells in a battery storage system, because if all battery cells in a battery storage system have similar properties and aging states, they deliver current evenly. This prevents individual battery cells from being overstressed, resulting in a more stable and efficient power output from the battery storage system.

[0038] Different aging states and properties of battery cells can lead to imbalances that increase the risk of overheating, short circuits, or other safety-related problems. A uniform aging state reduces these risks and contributes to the safe operation of the battery storage system.

[0039] Battery management systems (BMS) operate more efficiently when the battery cells have similar charging and discharging characteristics. This allows for more precise control and optimization of the charging and discharging cycles, which improves the overall performance and efficiency of the battery storage system.

[0040] Balancing strategies, which aim to equalize the charge between battery cells, work better when the battery cells have similar characteristics. This leads to more efficient energy use and prevents individual battery cells from being overcharged or undercharged.

[0041] According to a further embodiment, the following step is also included: cleaning the surfaces of the cell casing and / or the battery storage, before inserting the new battery cell into the cylindrical cavity.

[0042] A clean surface prevents dust, dirt, or other particles from entering the battery. Contaminants can lead to undesirable reactions, performance losses, and a shortened cell lifespan. Contaminants can also cause short circuits or other safety-related problems.

[0043] Clean surfaces ensure better adhesion of sealants, adhesives, or other materials used in repairs. This contributes to the mechanical stability and sealing of the battery cell.

[0044] According to a further embodiment, the insertion of a new battery cell into the cylindrical cavity in place of the removed battery cell or cell interior includes fixing the new battery cell with a thermally conductive potting compound.

[0045] Fixing a battery cell in a battery storage system with a thermally conductive potting compound offers the advantage that both a newly inserted battery cell can be firmly connected in place of the defective battery cell, as well as in place of a defective cell interior.

[0046] A thermally conductive potting compound improves heat dissipation from the battery cell to the surrounding structures. This helps to lower the cell's operating temperature and prevent overheating, thus increasing the cell's lifespan and performance. The thermally conductive potting compound ensures even heat distribution, preventing hotspots within the battery storage system. This results in a more uniform temperature distribution and improves the performance and lifespan of the battery cells.

[0047] The potting compound firmly fixes the battery cell in its position, minimizing mechanical stress and vibrations. This protects the cell from physical damage and contributes to the system's longevity.

[0048] The potting compound provides additional protection against moisture, dust, and other contaminants. This can reduce corrosion and degradation of battery components and improve system reliability.

[0049] According to a further aspect of the invention, the following step is further comprised: establishing the battery cell contact after inserting the new battery cell into the cylindrical cavity in place of the removed battery cell or the removed cell interior.

[0050] To restore the functionality of the battery storage system, the newly inserted battery cell can be connected to the other battery cells of the battery storage system.

[0051] Furthermore, it may be provided that the following step is included: sealing at least one exposed end face of the new battery cell in the battery storage system, after establishing the battery cell contact.

[0052] To restore the functionality of the battery storage system, the openings in the matrix material must be sealed and a cover applied.

[0053] According to a further aspect of the invention, the system for carrying out a method according to one of the preceding claims comprises a device for determining the position of a defective battery cell, a device for removing the defective battery cell or the cell interior of the defective battery cell in the direction of the longitudinal axis from the battery storage system, and a device for inserting a new battery cell into the cylindrical cavity at the place of the removed battery cell or the removed cell interior.

[0054] It has proven advantageous if the device for determining the location of a defective battery cell is already integrated into the battery storage system, as no further diagnostic equipment is then required. In battery storage systems for, e.g., motor vehicles, each individual battery cell is continuously monitored for its voltage. A resistive voltage divider is used for this purpose.

[0055] Furthermore, the device for determining the position of a defective battery cell can include an impedance spectrometer for performing electrochemical impedance spectroscopy.

[0056] It can also be advantageous if the device for determining the position of the defective battery cell includes a device for optical detection of, for example, an electrolyte leak.

[0057] It has proven particularly advantageous if the device for determining the position of a defective battery cell, in addition to determining the position of the defective battery cell, also determines the type of defect, the type of defect indicating whether the battery cell has faulty electrical properties or mechanical damage to the cell casing.

[0058] It has proven advantageous if the device for pressing the defective battery cell or the cell interior of the defective battery cell out of the battery storage unit in the direction of the longitudinal axis is designed as a hydraulic press with a ram. The same applies to a device for inserting a new battery cell into the cylindrical cavity at the location of the removed battery cell or the removed cell interior using a ram.

[0059] Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a battery storage system comprising an arrangement of cylindrical battery cells whose longitudinal axes are arranged parallel to each other, wherein the battery cells are embedded in a matrix material; Fig. 2 a schematic representation of a device for removing a defective battery cell and / or the cell interior of the defective battery cell in the direction of the longitudinal axis from the battery storage; Fig. 3 a schematic representation of a device for inserting a new battery cell or a new cell interior into place of the removed battery cell or cell interior; Fig. 4: A schematic representation of the process for replacing defective battery cells in a battery storage system.

[0060] Fig. Figure 1 shows a top view of a battery storage system 100 from an end face 140, comprising an arrangement of cylindrical battery cells 110 that are integrated directly without modules and whose longitudinal axes are arranged parallel to each other, the battery cells 110 being embedded in a matrix material 130. The battery cells 110 have a lower and an upper end face 140, with the lower end face 140 of the battery cell 110 facing the ground. The battery cells 110 are integrated into a housing 150 that securely holds and protects the battery cells 110 and ensures the mechanical integrity of the battery storage system 100. This housing 150 can be made of lightweight and strong materials such as aluminum or composite materials.

[0061] Not shown is a cell voltage monitoring system that ensures all cells remain within safe voltage limits. Also not shown is the battery contacting system, such as busbars and connectors, which connect the battery cells (110) to form a battery storage unit (100) and enable energy transfer.

[0062] Also included is a thermally conductive potting compound 160, which serves to improve the dissipation of heat generated in the battery cells 110. The matrix material 130 is, in particular, a foam, preferably a polyurethane foam, and serves to hold the battery cells 110 in place and to absorb mechanical shocks and vibrations. The matrix material 130 can also serve as a thermal insulator to control the temperature distribution within the battery storage unit 100.

[0063] Fig. Figure 2 shows a device 200 for removing a defective battery cell 110 or the cell interior of the defective battery cell 110 in the direction of the longitudinal axis from the battery storage unit 100. The device 200 comprises a punch 210, which is designed and configured to push the battery cells 110 or the cell interior out of the battery storage unit 100 in the direction of the longitudinal axes 120, and a drive device 220.

[0064] The removal of battery cell 110 or its interior depends on the type of damage detected. A distinction can be made between a defect in battery cell 110, such as electrolyte leakage after laser penetration during manufacturing, and a defect due to faulty electrical properties of battery cell 110 despite correct battery contact.

[0065] The device further comprises equipment (not shown here) for exposing at least one end face 140 of the defective battery cell 110 in a battery storage unit 100 and disconnecting the battery cell contacts. Exposing the at least one end face 140 of the battery cell 110 is carried out in two steps. In a first step, the housing 150 of the battery storage unit 100 is opened using a core drill and a spacer that limits the maximum drilling depth. In a second step, the underlying matrix material 130 is removed using a reamer or heated cutting blade and walnut shell blasting. Any chips produced can be extracted.

[0066] Furthermore, the device 200 includes, in the case that only the cell interior is to be removed, a device (not shown here) for aspirating the electrolytes. Electrolyte aspiration preferably takes place through a bore in an end face 140 of the cell shell and particularly preferably in the lower end face 140 (bottom) of the cell shell. This allows the electrolyte to be removed by utilizing gravity.

[0067] Furthermore, if only the cell interior is to be removed, the device 200 includes a device (not shown here) for opening at least one end face 140 of the cell wall. The end faces 140 (also called vents) are removed using a cutting or separating tool.

[0068] Depending on whether the entire defective battery cell 110 or just the cell interior is to be removed, the punch 210 has a corresponding cross-section. In the case of removing only the cell interior, the circumference of the punch 210 is smaller than in the case of removing the entire battery cell 110, and preferably has a diameter smaller than the inner diameter of the cell casing. In the case of removing only the battery cell 110, the punch 210 preferably has a diameter equal to that of the battery cell 110. In a further embodiment, the punch 210 can have a recess for the contact of the battery cell 110, which is attached to one of the end faces of the battery cell 110. Preferably, the punch 210 has a length at least equal to that of the battery cell 110 to allow for complete removal of the battery cell 110 or its interior.

[0069] A cylindrical cavity 230 is also shown, such as can be created when the defective battery cell 110 or the cell interior of the defective battery cell is removed from the battery storage unit 100 in the direction of the longitudinal axis. The circumference of the cylindrical cavity 230 can depend on whether a defective battery cell 110 or the cell interior of a defective battery cell 110 was removed.

[0070] Fig. Figure 3 shows a device 300 for inserting a new battery cell 330 into a cylindrical cavity 230 in place of the removed battery cell or cell interior.

[0071] The insertion device 300 is designed and configured such that the new battery cell 330 can be inserted, particularly from the upper end face 140 in the direction of the longitudinal axis 120, into a cylindrical cavity 230 in place of the removed defective battery cell or the removed cell interior. Insertion is preferably carried out by pressing or sliding.

[0072] The insertion device 300 may further comprise a positioning device 310 which positions the new battery cell 330 to be inserted into a cylindrical cavity 230 at the location of the removed battery cell or the removed cell interior.

[0073] The device 300 for inserting a new battery cell 330 into a cylindrical cavity 230 in place of the defective battery cell can further comprise a device (not shown here) for fixing the new battery cell 330 with a thermally conductive potting compound 160.

[0074] The device 300 according to the invention can comprise a device (not shown here) for making the battery contact and a device (not shown here) for sealing the at least one exposed end face 140 of the new battery cell 330 in the battery storage 100.

[0075] The exposed end face 140 of the new battery cell 330 in the battery storage unit 100 can be sealed with new matrix material 130 and a cover instead of the removed matrix material 130 and the opened housing 150 of the battery storage unit.

[0076] Furthermore, a device (not shown here) for cleaning the surfaces of the cell casing and / or the battery storage unit 100 may be provided. Such a device is specifically designed and equipped to remove dust and grease and / or residues of matrix material 130 or old thermally conductive potting compound 160 to ensure that the installed new battery cell 330 can function properly within the specified parameters.

[0077] According to the invention, the new battery cell 330 to be used can have a circumference which is smaller than or equal to the circumference of the cylindrical cavity 230.

[0078] This can mean that if a defective battery cell has been removed as a whole, a new battery cell 330 with the same or smaller size can be inserted, and preferably the new battery cell 330 is adapted so that it can be fitted into the cylindrical cavity 230.

[0079] In the case where only the cell interior has been removed, the circumference of the resulting cylindrical cavity 230 is smaller than when the entire defective battery cell is removed. Consequently, the circumference of the new battery cell 330 to be inserted is smaller than in the first case and is preferably adapted such that the circumference of the new battery cell 330 is smaller than the circumference of the cylindrical cavity 230 and is particularly preferably adapted so that it can be inserted into the cylindrical cavity 230 in a form-fitting manner.

[0080] The properties of the new battery cell 330 can be selected so that the cell aging and the electrical properties of the other battery cells of the battery storage system 100 are adapted and the performance data specified on the nameplate are achieved and a uniform load on the battery cells in the battery storage system 100 is ensured.

[0081] Fig.Figure 4 shows a flowchart illustrating a method 400 for replacing defective battery cells, comprising a cell shell and a cell interior in a battery storage unit, which includes an arrangement of cylindrical battery cells whose longitudinal axes are arranged parallel to each other, comprising the following steps: Determining 410 a position of a defective battery cell; Removing 440, 4412 the defective battery cell or the cell interior of the defective battery cell from the battery storage unit in the direction of the longitudinal axis, forming a cylindrical cavity with a circumference; Inserting 470 a new battery cell into the cylindrical cavity in place of the removed battery cell or the removed cell interior.

[0082] In order to selectively remove a defective battery cell or its internal components from a battery storage system, it is necessary to determine its position. This is usually done using a suitable measurement method, such as electrochemical impedance spectroscopy or a cell-specific voltage display. However, the position of the defective battery cell can also be determined by visual inspection, for example, by detecting electrolyte leakage. The type of battery defect can also be determined in this way.

[0083] Subsequently, the battery cell identified as defective, or its internal components, is removed (440, 4412) and replaced with a new battery cell (470). The selective removal (440, 4412) of the defective battery cell or its internal components has the advantage that the entire battery storage system does not have to be considered defective due to a single defective battery cell.

[0084] To remove the defective battery cell or the cell interior of the defective battery cell 440, 4412, the following steps must also be carried out: Expose 420 at least one end face of the defective battery cell in the battery storage and disconnect 430 the battery cell contacting.

[0085] In order to remove a defective battery cell or its interior along its longitudinal axis 440, 4412, the battery cell must be exposed 420. This is done in particular by removing the cover of the battery storage unit and the matrix material covering the arrangement of battery cells. Since the battery cells in the battery storage unit are connected by contacts, it is necessary for safety reasons and to avoid damage from short circuits, among other things, to disconnect the battery cell contacts before removing the battery cells 430.

[0086] Method 400 is characterized in that the removal 440, 4412 of the defective battery cell or the cell interior is carried out depending on the type of defect of the battery cell, wherein in the case of a faulty electrical property of the battery cell the cell interior is removed and in the case of damage to the cell shell the battery cell is removed.

[0087] By differentiating between the two types of faults, a targeted and resource-saving repair of the battery storage system is possible, and a replacement of the entire battery storage system can be avoided.

[0088] Method 400 is further characterized in that the removal 440, 4412 of the defective battery cells or the cell interior is carried out in the direction of the longitudinal axis by pushing them out.

[0089] By pushing out the cell, either the defective battery cell or the cell interior can be selectively removed, particularly by selecting an appropriate punch diameter 440, 4412. The cell interior, particularly the wound cell, can also be pulled out by a gripper 4112.

[0090] Since, when a new battery cell 470 is inserted into the cylindrical cavity, it can initially only be partially fitted in a form-fitting manner, and thus heat dissipation cannot be optimal, fixation 471 and improved heat dissipation can be achieved by introducing a thermally conductive potting compound. The thermally conductive potting compound is preferably introduced in liquid form into existing gaps between the inserted new battery cell and the battery storage unit after 470 has been inserted, and then cured.

[0091] In the case of removing 4412 the cell interior, the following additional step may be provided: Opening 4111 the cell casing of the defective battery cell at an upper and / or lower end face.

[0092] To remove 4412 the cell interior, which comprises an electrolyte and a wound cell, the electrolyte can first be removed. This is preferably done by drilling a hole in the lower end face (bottom) of the battery cell, from which the electrolyte can be extracted by gravity. The electrolyte can also be removed by opening 4111 the upper and lower end faces of the battery cell.

[0093] After the electrolyte has been removed, the top and bottom ends of the battery cell (also called vents) can be removed. This is preferably done using a can opener, so that only the side walls of the cell casing remain.

[0094] The cell can then be removed. This can be done by pulling it out or, preferably, by pushing it out. When pulling it out, only the top or bottom end of the battery cell can be removed.

[0095] When ejecting the cell, the plunger used preferably has a diameter no larger than the inner diameter of the cell wall. Particularly preferably, the plunger's diameter is large enough to rest against the inside of the cell wall to enable ejection with minimal residue.

[0096] Method 400 is characterized by the fact that the new battery cell to be inserted has a circumference that is equal to or smaller than the circumference of the cylindrical cavity.

[0097] In particular, the size of the new battery cell is chosen so that it can be inserted into the cavity in a form-fitting manner.

[0098] Method 400 can include, when inserting 470 a new battery cell into the cylindrical cavity in place of the removed battery cell or the removed cell interior, fixing 471 the new battery cell with a thermally conductive potting compound, wherein fixing 471 is particularly advantageous when the circumference of the new battery cell is smaller than the cavity.

[0099] Method 400 is further characterized by the fact that the properties of the newly inserted battery cell can be adapted to the cell aging and electrical properties of the other battery cells in the battery storage system. This is particularly advantageous because it ensures that the battery cells in the battery storage system have the same performance parameters and cell lifetimes, thus guaranteeing the most trouble-free operation possible of the battery storage system.

[0100] The following process steps are also included: Cleaning 450 of the surfaces of the cell casing and / or the battery storage before inserting the new battery cell into the cylindrical cavity; establishing 480 the battery cell contact after inserting 470 a new battery cell at the position of the defective battery cell and sealing 490 the at least one exposed end face of the new battery cell in the battery storage.

[0101] Cleaning the surfaces (450) serves to bring the components into a state free of contaminants, so that contacting the cell interior and / or the battery cells is easily possible.

[0102] After repairing the defective battery cell by replacing it, it is necessary to reconnect the previously separated battery contacts 480 in order to obtain a functioning battery storage system.

[0103] Subsequently, the battery cell 490 is resealed in the battery storage unit for its intended use. Reference symbol list 100 battery storage units 110 battery cells 120 Longitudinal axis 130 matrix material 140 Front 150 cases 160 thermally conductive potting compound 200 Device for removing the defective battery cell or the cell interior of the defective battery cell 210 stamps 220 Drive unit 230 cylindrical cavity 300 Device for inserting a new battery cell 310 Positioning device 330 new battery cells 400 methods for replacing defective battery cells 410 Determining the position of a defective battery cell 420 Exposing at least one end face of the defective battery cell 430 Disconnecting the battery cell contacts 440 Removing the defective battery cell 4411 Opening the cell casing of the defective battery cell 4412 Removal of the cell interior 450 Cleaning the surfaces 470 Inserting a new battery cell 471 Fixing the new battery cell 480 Making the battery cell contacts 490 Sealing the at least one exposed end face of the new battery cell in the battery storage system QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 102426946 A1

[0010] EP 3 930 074 B1

[0011] CN 112310562

[0011] CN 109904544 A

[0012]

Claims

[1] Method for replacing (400) a defective battery cell (110), comprising a cell shell and a cell interior, in a battery storage system (100), which includes a particularly non-modular arrangement of cylindrical battery cells (110) whose longitudinal axes (120) are arranged parallel to each other, comprising the following steps: - Determining (410) the position of a defective battery cell (110); - Removal (440, 4412) of the defective battery cell (110) or the cell interior of the defective battery cell (110) in the direction of the longitudinal axis (120) from the battery storage (100) forming a cylindrical cavity (230) with a circumference; and - Inserting (470) a new battery cell (330) into the cylindrical cavity (230) in place of the removed battery cell (110) or the removed cell interior. [2] The method of claim 1, further comprising the following steps: - Exposing (420) one end face (140) of the defective battery cell (110) in the battery storage unit (100), and - Disconnecting (430) the battery cell contact of the defective battery cell (110). [3] Method according to one of the preceding claims, wherein the removal (440) of the defective battery cells (110) or the cell interior in the direction of the longitudinal axis (120) is carried out by pressing out. [4] Method according to any one of the preceding claims, wherein - in addition to determining (410) the position of the defective battery cell (110), the type of defect is also determined, the type of defect indicating whether the battery cell (110) has faulty electrical properties or mechanical damage to the cell shell, and - the removal (440, 4412) of the defective battery cell (110) or the cell interior depending on the type of defect of the battery cell (110) is carried out, wherein in the event of a faulty electrical property of the battery cell (110) the cell interior of the battery cell (110) is removed and wherein in the event of damage to the cell shell the entire battery cell (110) is removed. [5] Method according to any of the preceding claims, further comprising, in the case of removing the cell interior of the defective battery cell (110), the following step: - Opening (4411) the cell casing of the defective battery cell (110) at an upper and / or a lower end face (140) to remove the cell interior. [6] Method according to one of the preceding claims, wherein the new battery cell (330) to be used has a circumference which is equal to or smaller than the circumference of the cylindrical cavity (230). [7] Method according to one of the preceding claims, wherein the properties of the newly inserted battery cell (330) are adapted to the cell aging and electrical properties of the further battery cells (110) of the battery storage system (100). [8] A method according to any one of the preceding claims, further comprising the following step: - Cleaning (450) of the surfaces of the cell casing and / or the battery storage (100) before inserting (470) the new battery cell (330) into the cylindrical cavity (230). [9] Method according to one of the preceding claims, wherein the insertion (470) of a new battery cell (330) into the cylindrical cavity (230) in place of the removed battery cell (110) or the removed cell interior comprises fixing (471) the new battery cell (330) with a thermally conductive potting compound (160). [10] A method according to any of the preceding claims, further comprising the following step: - Establishing (480) the battery cell contact, after inserting the new battery cell (330) into the cylindrical cavity (230) in place of the removed battery cell (110) or the removed cell interior. [11] A method according to any of the preceding claims, further comprising the following step: - Sealing (490) the at least one exposed end face (140) of the new battery cell (330) in the battery storage (100), after making (480) the battery cell contact. [12] System for carrying out a method comprising one of the preceding claims: - a device for determining the position of a defective battery cell (110), - a device for removing (200) the defective battery cell or the cell interior of the defective battery cell (110) in the direction of the longitudinal axis (120) from the battery storage (100), and - a device for inserting (300) a new battery cell (330) into the cylindrical cavity (230) in place of the removed battery cell (110) or the removed cell interior.

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