Method and device for checking, categorizing, and preparing a process for recycling lithium-ion batteries

Abstract

The invention relates to a method and a device for checking and preparing a process for recycling lithium-ion battery units (1.1). Multiple battery units (1) are combined in a battery pool (2) and are electrically connected together via a BUS line system (10) in order to exchange electric energy. Battery units (1.1) of the battery pool (2) are charged and / or discharged for the purpose of checking the battery and / or preparing the recycling process, wherein electric energy released by discharging at least one battery unit (1.1, 1.4) of the battery pool (2) is used to charge at least one other battery unit (1.1) of the battery pool (2) via the BUS line system (10).

Description

[0001] METHOD AND DEVICE FOR TESTING, CATEGORISATION AND RECYCLING PREPARATION

[0002] OF LITHIUM-ION BATTERIES

[0003] The invention relates to the field of battery recycling. It concerns a method and a device for testing, categorizing, and preparing battery units, in particular lithium-ion battery units, for recycling.

[0004] In the context of this patent application, a battery unit is understood to mean both a battery or accumulator and an individual cell of a battery or accumulator.

[0005] For the purposes of this patent application, a battery is defined as an electrochemical storage device for electrical energy. An accumulator is defined as a rechargeable battery.

[0006] Lithium-ion batteries, such as lithium-ion accumulators, which are designed for high voltages and / or power levels, are usually made up of a large number of individual cells that are connected to each other via a series circuit (higher voltage) and / or parallel circuit (higher capacity).

[0007] A cell is the basic, smallest electrochemical, power-producing unit of a battery or accumulator, comprising two electrodes, an electrolyte, a separator, and possibly its own housing. Technically speaking, the individual cell can function as a standalone battery energy source. A cell therefore contains at least one electrode stack consisting of a cathode, an anode, and the associated electrical conductors, as well as one or more separators. A cell can be constructed from one or more electrode stacks.

[0008] Lithium-ion batteries are becoming increasingly popular among rechargeable batteries due to their comparatively high specific energy.

[0009] In addition to their use in mobile electronic devices such as laptops, digital cameras, mobile phones, tablets, and other mobile devices such as flashlights or cordless power tools, the use of lithium-ion batteries is gaining increasing importance, particularly in the growing electromobility sector. Lithium-ion batteries serve as energy storage devices in electromobility, for example, for electric cars, hybrid vehicles, electric bicycles, electric scooters, and other electric vehicles.

[0010] The rising demand for electric vehicles is also leading to a sharp rise in demand for lithium-ion batteries. The future restrictions on the registration of combustion engines, already planned in some countries, will further accelerate this trend.

[0011] Lithium-ion batteries or accumulators is a collective term for batteries or accumulators in which an active material containing lithium, e.g. a lithium metal oxide or a metal oxide doped with lithium, is used on the positive electrode (cathode). The active material is applied in the form of a coating to a current-carrying conductor (carrier), which can be made of (pure) aluminum, for example. The active material is embedded, for example, in a carrier material, which also serves as a binder in the coating of the electrical conductor. The active material of the negative electrode (anode) comprises, in particular, elemental carbon. The active material comprises, in particular, graphite or consists of it. The active material is also applied in the form of a coating to a current-carrying conductor (carrier) of the anode, such as copper.

[0012] The active materials include the chemically active substances that are responsible for energy storage in batteries and which are optionally applied to the current-carrying conductor (carrier) via binders.

[0013] An electrically insulating separator is arranged between the anode and cathode to prevent direct electrical contact between the anode and cathode. The separator is typically made of a non-conductive material, such as plastic, e.g., polyethylene or polypropylene.

[0014] The assembly of cathode, separator, and anode is surrounded by an electrolyte, which ensures the movement of the lithium ions between the anode and cathode. The electrolyte is particularly fluid.

[0015] Lithium-ion batteries are characterized by the fact that the lithium ions can move between the anode and cathode and through the separator during charging / discharging. This means that when the battery is charging, positively charged lithium ions move from the cathode through the separator to the anode, where they accumulate. During discharging, the lithium ions migrate back through the separator to the cathode.

[0016] For example, lithium cobalt dioxide batteries, lithium nickel manganese cobalt oxide (NMC) batteries, and lithium iron phosphate or lithium ferrophosphate batteries (LFP) are known. The electrode packs are housed in a cell housing, which also contains the electrolyte, in which the electrode pack is usually immersed. The housing can be made of plastic or metal, such as aluminum. A metal housing has the advantage that the electrolyte cannot diffuse through it.

[0017] In common battery types, the cathode, anode, and separator are layered materials, such as strips. The strips are formed, for example, as foils.

[0018] Lithium-ion batteries that can no longer be regenerated due to, for example, aging, loss of electrolyte, or a defect (e.g., due to deep discharge) must be disposed of properly. Since lithium-ion batteries, like other battery types, contain environmentally harmful substances, they are generally disassembled into their original components, and the individual components are recycled or processed separately. This process is referred to as "recycling" in this patent application.

[0019] However, worn-out or decommissioned lithium-ion batteries are not necessarily inoperable. Therefore, they do not always need to be recycled, but can be used in other applications, such as stationary batteries (second life).

[0020] Therefore, it is common practice to inspect the condition of used or decommissioned lithium-ion batteries or accumulators in advance using a battery testing device and assign them to a condition category. Those lithium-ion batteries or accumulators that can no longer be reused are prepared for the recycling process and sent for recycling. Typically, both whole, used batteries or accumulators and individual battery cells, e.g., from disassembled, used batteries, are recycled. Thus, both whole batteries and individual battery cells must be handled during battery recycling.

[0021] Testing lithium-ion batteries, accumulators, or battery cells, as well as preparing them for recycling, involves charging and discharging processes that require or release electrical energy. Until now, it was common practice to draw this electrical energy from the public power grid or feed it into it. However, due to high electricity prices and comparatively low feed-in tariffs, high electricity costs arise for testing larger quantities of lithium-ion batteries or accumulators. Furthermore, there is a dependency on the public power supply, which can lead to problems, especially during periods of power shortages.

[0022] It is therefore an object of the present invention to propose a method and an associated device for testing, categorizing and preparing for recycling of used or decommissioned battery units, in particular lithium-ion battery units, which can be operated as autonomously as possible, ie independently of the public power supply.

[0023] Furthermore, the process should be as simple, efficient, and cost-effective as possible. The process should also feature the highest possible degree of automation. Furthermore, the associated equipment should be as simple as possible and require little maintenance.

[0024] At least one of the objects is achieved by independent claims 1 and 18. The dependent claims, as well as the description and the figures, contain particular embodiments and developments of the invention. Battery testing, categorization, and recycling preparation are particularly part of the so-called battery preparation.

[0025] The procedure for testing and preparing battery units for recycling, especially lithium-ion battery units, is now characterized by the fact that several battery units are combined in a battery pool and connected to each other via a BUS line system for the exchange of electrical energy.

[0026] Battery units of the battery pool are now charged and discharged for battery testing and / or recycling preparation, whereby electrical energy released by discharging a battery unit of the battery pool is used via the BUS line system, in particular to charge another battery unit of the battery pool.

[0027] The term "battery pool" refers to those battery units that are connected to the BUS line system, particularly via battery connections.

[0028] According to a further development, at least one battery unit of the battery pool is referenced during the battery test by at least one charging process, wherein the at least one battery unit is charged via the BUS line system at least partially, in particular completely, with electrical energy released by discharging another battery unit of the battery pool.

[0029] The battery unit can be subjected to a voltage test before or during referencing. If the voltage test reveals that the battery unit can no longer be charged, e.g., due to deep discharge or a short circuit, the battery unit is excluded from the test item and categorization process and assigned to the "recycling" category or another category. According to a further development, at least one charging process is carried out on at least one battery unit in the battery pool as part of the battery test in order to determine battery status information. In this process, the at least one battery unit is at least partially, in particular completely, charged via the BUS line system with electrical energy released when another battery unit in the battery pool is discharged.

[0030] According to a further development, battery status information is determined for at least one battery unit of the battery pool as part of the battery test by means of at least one charging and discharging cycle, wherein the at least one battery unit is charged via the BUS line system at least partially, in particular completely, with electrical energy released by discharging at least one other battery unit of the battery pool.

[0031] However, the battery test does not necessarily include a charge and discharge cycle with full charge and discharge of at least one battery unit.

[0032] According to a further development, the at least one above-mentioned battery unit is at least partially, in particular completely, charged with electrical energy which is released by discharging at least one other battery unit of the battery pool as part of a referencing of the at least one other battery unit.

[0033] According to a further development, the at least one aforementioned battery unit is at least partially, in particular completely, charged with electrical energy, which is released by discharging at least one other battery unit of the battery pool during the battery test for the purpose of determining battery status information. According to a further development, the at least one aforementioned battery unit is at least partially, in particular completely, charged with electrical energy, which is released by discharging at least one other battery unit of the battery pool during at least one charging and discharging cycle of the battery test for the purpose of determining battery status information.

[0034] According to a further development, the at least one battery unit mentioned above is at least partially, in particular completely, charged with electrical energy which is released by discharging at least one other battery unit of the battery pool for the purpose of recycling preparation.

[0035] According to a further development, at least one electrical consumer, such as battery testing device, charging and discharging device and / or power converter of the device, is operated via the BUS line system at least partially, in particular completely, with electrical energy released by discharging at least one battery unit of the battery pool, wherein the electrical energy in particular:

[0036] - is released by discharging at least one battery unit of the battery pool during referencing of at least one battery unit;

[0037] - is released by discharging at least one battery unit of the battery pool during at least one discharge process or charge and discharge cycle of the battery test for the purpose of determining battery status information, and / or

[0038] - is released by discharging at least one battery unit from the battery pool for the purpose of recycling preparation.

[0039] The aforementioned at least one battery unit or the aforementioned at least one electrical consumer can also be charged, in particular partially, with electrical energy drawn from the public power grid and / or from a backup battery. The battery units of a battery pool can be classified into one of at least two battery unit condition categories during testing, comprising a first category "reuse" and a second category "recycling."

[0040] The categorization is carried out primarily by a central control device. The categorization is carried out primarily by database support. The categorization is carried out primarily by automation.

[0041] The method or the associated device provides, in particular, at least two groups of battery units in the battery pool. These include, in particular, a testing and categorization group and a recycling group.

[0042] For example, battery units with unknown charge and / or unknown general condition are assigned to the testing and categorization group. These battery units are categorized using a testing procedure.

[0043] Tested battery units in good general condition are classified in the "reuse" category, and batteries in poor general condition are classified in the "recycling" category.

[0044] Battery units in the "Recycling" category are assigned to the recycling group for recycling preparation.

[0045] Battery units in the "Reuse" category are removed from the battery pool, especially after they have been brought to a specified charge level. Categorization or group allocation is primarily carried out virtually. This means that the battery units do not necessarily have to be reconnected according to categories or groups. However, the group allocation can be digitally mapped by the control system.

[0046] It may also be the case that a battery unit is not suitable for reuse from the outset, for example, because its poor general condition is already known. Accordingly, a condition check of the battery unit is not required, and the battery unit can be directly assigned to the "Recycling" category and thus allocated to the recycling group.

[0047] The battery units of the recycling group are discharged in the battery pool to a final voltage suitable for the subsequent recycling process.

[0048] The associated device for implementing the method according to the invention comprises a bus line system. This serves to exchange electrical energy between the battery units of the battery pool. For this purpose, the device also contains a plurality of battery terminals for connecting battery units to the bus line system.

[0049] The device contains in particular a plurality of battery preparation stations or test stations for at least one battery unit each with a battery connection.

[0050] At the battery preparation station or testing station, at least one battery unit is subjected to a test and / or at least one charging and / or discharging process as part of the testing, categorization, and recycling preparation process. The battery connection corresponds specifically to a single power connection channel to the bus line system. This includes a positive and negative pole.

[0051] The battery preparation stations or testing stations are each equipped in particular with a station control unit (controller) for controlling the battery testing and / or recycling preparation and accordingly at least one charging and / or discharging process.

[0052] The battery testing device and / or the charging and discharging device and, if applicable, also the power converter are in particular part of the battery preparation station or testing station.

[0053] A single battery containing multiple battery cells, or a battery module with multiple battery cells, can now be connected to the battery connector for testing and categorization or recycling preparation.

[0054] It is also possible to connect a single battery cell to the battery terminal.

[0055] According to a further development of the invention, the battery preparation stations or test stations for connecting multiple battery cells to a battery terminal each have a battery cell connection device. The battery cell connection device comprises a plurality of cell control units (cell controllers). The cell control units are each connected to a power supply line, which is itself connected to the battery terminal or the power connection channel.

[0056] The cell control units are connected in series to the power supply line. However, it is also conceivable for the cell control units to be connected in parallel to the power supply line. Each cell control unit has a battery cell connection, to which a (single) battery cell can be connected. The cell control units individually control the charging and / or discharging processes of the battery cells as part of the recycling preparation and, if necessary, testing and categorization. For this purpose, the cell control units contain, in particular, a charging and / or discharging device.

[0057] The battery cell connection device is designed in particular so that charging and / or discharging processes can be carried out simultaneously on several connected battery cells.

[0058] In particular, the cell control units each have a bridging device for bridging individual battery cells connected to the cell control units or individual battery cell connections.

[0059] The battery cell connection device is designed, in particular, for individually discharging individual battery cells. However, it can also be provided that the battery cell connection device is also designed for testing the battery cells, which is particularly associated with charging and discharging processes. Accordingly, the cell control units can also include a testing device.

[0060] The battery cell connection device is designed specifically for testing and categorizing and / or preparing identical battery cells for recycling.

[0061] The cell control units monitor and control the recycling preparation process and / or testing and categorization of the individual battery cells, and accordingly, the charging and / or discharging processes on the individual battery cells. The station control unit, in turn, acts as a higher-level control unit, specifically monitoring and controlling the cell control units via a communication or data line that connects the cell control units to the station control unit. The station control unit coordinates, in particular, the charging and discharging processes of the individual cell control units.

[0062] Since the battery cells are individually subjected to testing and categorization and / or recycling preparation via the cell control units, the testing and categorization and / or recycling preparation can be adapted to the initial state of charge (SOC) of the connected battery cells, which can vary between the battery cells.

[0063] The cell control units monitor the charge level of the battery cells, particularly via the voltage of the battery cell.

[0064] If a battery cell has reached a specified charge level, e.g. the battery cell is discharged to a final voltage, the battery cell in question is bridged by the cell control unit using the bridging device.

[0065] Bridging individual battery cells allows for dynamic management of the battery cell connection device. This is achieved by allowing individual battery cells to be connected to or disconnected from the battery cell connection device independently of the other connected battery cells during ongoing operation. This allows battery cells whose testing and categorization and / or recycling preparation have been completed, i.e., on which no further charging and / or discharging processes are being performed, to be bridged.

[0066] Furthermore, the bridging device can also be used to

[0067] Bridge battery cell connections. The battery preparation stations or test stations can be designed for connecting multiple battery cells via the battery connection or the common power connection channel using the battery cell connection device described above, as well as for connecting one battery or battery module at a time via the battery connection.

[0068] It can be provided that at the battery preparation stations or test stations, either a battery or a battery module containing several battery cells or a battery cell connection device accommodating several battery cells is connected via the battery connection.

[0069] When a battery or battery module is connected via the battery connector, the procedure for testing, categorisation and / or recycling preparation, and consequently charging and / or discharging processes, is controlled via the station control unit.

[0070] The bus line system is, in particular, an internal power distribution system for distributing electrical energy within the device according to the invention, in particular between the battery units connected to the battery pool. The bus line system corresponds, in a figurative sense, to a busbar or bus line.

[0071] The battery units of the battery pool are connected in parallel via the BUS line system.

[0072] The associated device is designed in particular to operate the BUS line system with a standardized voltage, in particular direct voltage. This means that the electrical energy transported through the BUS line system has a fixed or defined voltage or direct voltage, which may deviate from the nominal voltage(s) of the battery units. Accordingly, a power converter, in particular a DC-DC converter or DC-current converter (e.g. DC / DC converter), is arranged between the battery connections and the BUS line system for the purpose of converting the voltage, in particular the direct voltage, between the battery units and the BUS line system. The power converter is in particular a bidirectional power converter. The power converter can, for example, be a DC / DC converter controller, as can also be integrated, for example, in a motor controller.

[0073] The electrical energy is therefore converted from the standardized voltage, in particular DC voltage, of the BUS line system to another voltage, in particular DC voltage, e.g. to the respective nominal voltage of the battery unit, and vice versa, via power converters, in particular DC voltage converters, which are assigned to the battery units.

[0074] The power converter can be designed as a separate device or integrated into another device or device, such as a charging and discharging device or a battery testing device.

[0075] In particular, the battery testing device, the charging and discharging device as well as the power converters or transformers are not to be understood as physical or structural units but as functional units or functional units.

[0076] The battery testing device and charging and discharging device can also represent a common functional unit, since the battery test itself also includes charging and discharging processes.

[0077] According to a further development, the battery testing device and the charging and discharging device are operated via a common control unit (controller), such as a cell control unit or station control unit. If necessary, the power converter can also be operated via the aforementioned common station control unit (controller).

[0078] It is therefore possible for the charging and discharging device and the battery testing device and, if applicable, also the power converter to be housed in a common device or base module, which also forms the battery connection.

[0079] The battery cell connection device can be designed as a device or connection module which is connected to the base module via the battery connection.

[0080] The specification of a standardized voltage or direct voltage in the BUS line system allows the exchange of electrical energy between battery units with different nominal voltages, as well as, if necessary, the supply of electrical consumers of the device with electrical energy.

[0081] For battery units that are sorted out or decommissioned and returned, both the state of charge (SOC) and the battery condition (SOH, state of health) are usually unknown.

[0082] Therefore, according to the invention, it is particularly provided that, as part of a battery test, the SOH (state of health) of the battery units in the battery pool, i.e., battery condition information, is determined using a battery testing device. The determined battery condition information should allow the categorization of the battery units. For this purpose, the battery testing device executes a test program on the battery unit, which, for example, comprises at least one charging and / or discharging process, in particular at least one charging and discharging cycle.

[0083] If the charge level is unknown, a battery referencing test can be performed, particularly as part of the battery test, in which the battery is charged or discharged at least once. During referencing, the battery is charged to the final charge voltage or discharged to the final discharge voltage. Referencing the battery unit is performed, particularly before the actual battery test, to determine status information.

[0084] If necessary, battery data, such as the battery's history, can also be accessed to determine the battery's condition. The battery data can also include operating data, which is stored, for example, in the battery management system (BMS) and read by the battery testing device. Furthermore, data, such as operating data, from external sources, such as a digital battery passport, can also be taken into account.

[0085] The battery management system (BMS) is an electronic unit within a battery which, among other things, serves to monitor, control and protect the battery.

[0086] The battery management system (BMS) can include functions such as charge level detection, deep discharge protection, and overcharge protection. The battery management system (BMS) can also be designed to collect, store, display, and / or transmit operating data. For example, the battery management system (BMS) can include a data interface.

[0087] Battery management systems (BMS) may be necessary, especially when several cells are connected in series to form a battery.

[0088] Battery data can be read from a battery management system (BMS) or a digital battery passport and imported into the central database, where it can be included in the overall assessment of the battery's condition. Battery testing, particularly using a battery testing device, can include at least one of the following measurement methods:

[0089] - Capacitance measurement using a capacitance measuring device;

[0090] - Internal resistance measurement using an internal resistance measuring device,

[0091] - Impedance measurement (electrochemical impedance spectroscopy).

[0092] The battery test is used in particular to determine battery condition information, whereby the battery condition information is used to assign the battery units to one of at least two condition categories.

[0093] The battery condition information is determined in particular by the battery testing device using electrochemical impedance spectroscopy (EIS).

[0094] This method is faster than other methods such as capacitance measurement, which is advantageous when batteries are subject to high throughput.

[0095] The determination of the battery status information or the battery test comprises in particular at least one charging and / or discharging process or at least one charging and discharging cycle.

[0096] For categorizing the battery units, the device contains, in particular, an evaluation device, which is operated in particular with evaluation software. The evaluation device can be part of the battery testing device. The evaluation device can also be part of a higher-level or central control device that controls the battery testing device.

[0097] The battery condition information determined from a measurement can, for example, be the capacity or capacity loss of the battery unit. For example, battery units whose capacity loss does not exceed a certain threshold can be assigned to a "reuse" condition category. Such battery units with slightly to moderately reduced capacity can still be used, for example, for stationary energy storage.

[0098] Battery units that exceed the threshold, i.e., exhibit excessive capacity loss, can be assigned to the "Recycling" category. This means that these battery units are recycled, for example, by disassembling them into individual components and recycling them. The threshold can be, for example, 30% capacity loss.

[0099] For battery testing, the device contains battery testing devices for the battery units, arranged in particular between the battery terminals and the bus line system, in particular between the battery terminals and the power converters, to determine battery status information. The battery testing devices are, in particular, part of the test stations.

[0100] To carry out charging and discharging steps or charging and discharging cycles as part of referencing or battery testing, as well as, if necessary, discharging as part of recycling preparation, each battery terminal is also assigned a charging and discharging device. This is arranged, in particular, between the battery terminal and the power converter, and especially between the battery testing device and the power converter. The charging and discharging devices can each be designed as a separate device. The charging and discharging devices can also be integrated into the battery testing device or the power converter. The charging and discharging device is, in particular, part of the test station.

[0101] The battery units are classified into at least two condition categories based on the determined battery condition information. These at least two condition categories include, in particular, a first category, "Reuse," and a second category, "Recycling." Optionally, a third category or subcategory, "Partial Reuse," may be provided. Battery units in the third category or subcategory "Partial Reuse" are batteries in which individual cells, but not all cells, are reusable. Battery units in the third category are opened in the same way as battery units in the second category, with the reusable cells being designated for reuse and the remaining cells and battery parts being designated for recycling.

[0102] Following testing and categorization, battery units in the "reuse" or "fully reuse" categories are brought to a charge level suitable for storage. The charge level lies between fully charged and fully discharged. Depending on the charge level after completion of the battery test, this can mean charging or discharging the battery unit. Here, too, the energy for charging the battery units is drawn at least partially, but in particular completely, from the bus line system, or the energy released during discharging is fed into the bus line system to charge other batteries.

[0103] The electrical energy for charging the battery units can therefore come at least partially, or even entirely, from the electrical energy released when other battery units are discharged. This can also be temporarily stored electrical energy from a buffer battery.

[0104] The energy used to discharge the battery units is also used at least partially, and in particular entirely, to charge other battery units. The electrical energy for this purpose can also be temporarily stored in a buffer battery. However, the electrical energy used to charge the battery units can also be obtained, in particular partially, from the public power grid.

[0105] Battery units in the battery pool that are assigned to the "Recycling" status category after completion of the battery testing and categorization are prepared for the recycling process in a subsequent process step, i.e., following the battery testing and categorization. Recycling preparation includes, in particular, discharging the battery unit. The discharging process takes place primarily before disassembly or opening the battery unit.

[0106] The discharging process for recycling preparation also takes place in the test station or battery pool, i.e., via the same battery connection. This has the advantage that the battery units do not have to be fed into a separate discharging facility for recycling preparation.

[0107] When discharging the battery unit in preparation for recycling, it is not discharged to deep discharge, but only to a cut-off voltage. However, the battery units can also be deeply discharged, particularly depending on the recycling process.

[0108] When the final discharge voltage is reached, the battery unit has practically no electrochemical energy left, although a potential is still present. However, the potential of the final discharge voltage is merely a measure of the difference between the voltage of the oxidizing agent and the reducing agent in the cell and not a measure of the energy that remains inside the cell. In other words, the final discharge voltage is an apparent voltage that corresponds to the cell's own electrochemical voltage. The battery unit is discharged in particular actively. Active discharge is understood to mean a controlled, i.e., regulated discharge, particularly via the charging and discharging device. The discharge process is in particular automated.

[0109] Actively discharging the cell, especially to the cut-off voltage, has the advantage that no side reactions occur with lithium and the other components in the cell. This means that the cell does not enter a state of stress or become damaged.

[0110] The final discharge voltage depends on the specific battery type. For example, for a lithium-ion battery, the final discharge voltage is around 2 volts. This is especially true for lithium iron phosphate batteries.

[0111] Since the test program and the test parameters also depend in particular on the battery type, the battery type and cell type are also determined in connection with the battery preparation.

[0112] The prior identification of the battery type is an important part of the testing and categorization process as well as the recycling preparation, as it ensures that the correct test programs or test parameters or discharge programs or discharge parameters are used for each battery type.

[0113] The determination of the battery type can be automated, e.g., during battery preparation.

[0114] Automatic battery type detection can be achieved by incorporating various (historical) data stored in the database, which enables or supports battery identification. The following data stored in the database can be used individually or in combination to automatically determine the battery type:

[0115] - Data from the digital battery passport: By accessing this data, the system can automatically identify the battery type and retrieve relevant information such as nominal voltage, capacity, and recommended discharge parameters for the upcoming test. This enables precise assignment of the battery to specific test programs.

[0116] - Data from the battery management system (BMS): Modern batteries are often equipped with a battery management system (BMS) that contains important data on the battery type, as well as the SOH and SOC. Querying the BMS allows for direct identification of the battery type, which simplifies the automated adaptation of testing and discharging processes to the specific requirements of the battery.

[0117] Furthermore, during incoming inspection, markings or information carriers attached to the battery (such as QR codes, barcodes, or serial numbers) can be automatically read (e.g., scanned) or manually entered. This identification data is then compared with a database containing specific information about each battery type. The battery type can then be determined from the data comparison.

[0118] The battery type can also be determined by trained personnel, e.g. visually, and recorded manually.

[0119] Another option for recording the battery type is prior manual identification and categorization by trained personnel, who then sort the batteries by type and temporarily store them in storage locations. When placing the batteries in the battery pool, the operator removes batteries from the appropriate storage locations. The device automatically identifies the battery type and automatically loads the appropriate test programs and test parameters based on the storage location from which the battery was removed.

[0120] It may be provided that battery units or batteries assigned to a third category or subcategory "partial reuse" are also discharged, in particular to a final discharge voltage that allows the safe removal of cells from the battery unit or battery without damaging the cell chemistry. This released electrical energy can also be used to charge battery units in the battery pool, as described above.

[0121] According to the invention, as mentioned, electrical energy released by discharging a battery unit from the battery pool for the purpose of preparing for recycling is used to charge at least one battery unit from the battery pool. The charging of the at least one battery unit takes place in particular as part of a referencing or testing procedure for determining battery status information.

[0122] The battery units in the "Recycling" condition category that have been discharged or discharged to the final discharge voltage can now be fed into the recycling process.

[0123] As mentioned above, the battery units added to the battery pool are each connected to a battery testing device or a charging and / or discharging device via the battery connector. The battery testing device performs the test procedure, which determines battery status information.

[0124] The test procedure includes, in particular, an initial charging or discharging of the battery units for referencing purposes. The battery units are then brought or regulated to a charge level determined for further testing. For this purpose, the test procedure may include at least one charging and discharging cycle.

[0125] According to the invention, the electrical energy required for charging the battery units during the test procedure is obtained from the electrical energy released by discharging other batteries.

[0126] Analogously, the electrical energy released during the test procedure when discharging the battery units is used according to the invention to charge other batteries.

[0127] The charging of battery units using electrical energy released by discharging other batteries from the battery pool can be done directly by using the electrical energy released by discharging processes to charge other battery units within the battery pool without intermediate storage via the BUS line system.

[0128] This allows multiple batteries in a battery pool to be charged simultaneously for various reasons mentioned above, e.g., for referencing or battery testing, and multiple battery units in the battery pool to be discharged simultaneously for various reasons mentioned above, e.g., for referencing, battery testing, or recycling preparation. A higher-level control system controls or regulates the current flows between the feeders and the consumers accordingly.

[0129] The method according to the invention and the associated device allow the simultaneous charging and / or discharging of battery units of different types for the purpose of testing, categorization, and / or recycling preparation. According to a further development, the device contains at least one buffer battery for temporarily storing electrical energy, in particular excess electrical energy, which is released when battery units of the battery pool are discharged and for feeding electrical energy into the bus line system, in particular for charging battery units of the battery pool.

[0130] The buffer battery can also supply electrical energy to operate at least one electrical consumer of the device.

[0131] The buffer battery is connected to the bus line system accordingly. The buffer battery is connected to the bus line system via a power converter, particularly a DC-DC converter.

[0132] Accordingly, according to this further development, excess electrical energy which is fed into the BUS line system by discharging battery units of the battery pool and which is not required to charge other battery units of the battery pool can be stored in the buffer battery.

[0133] Furthermore, electrical energy which is required to charge battery units of the battery pool and which cannot be provided by discharging other battery units of the battery pool can be obtained from the buffer battery via the BUS line system.

[0134] Accordingly, the battery units can also be charged indirectly by temporarily storing the electrical energy released during discharge in the buffer battery and only later feeding it back into the bus line system to charge other battery units or the same battery units from the buffer battery. Intermediate storage in a buffer battery occurs primarily to balance the supply of electrical energy fed in by discharging battery units and the demand for electrical energy to charge battery units. This means that excess energy in the bus line system is temporarily stored in the buffer battery, and any excess demand for electrical energy in the bus line system is met by feeding electrical energy from the buffer battery into the bus line system.

[0135] As mentioned above, the device according to the invention contains, in particular, a higher-level or central control device, via which the power management in the bus line system takes place. This means that the control device controls the current flow in the bus line system. The control device also ensures, in particular, a stable voltage in the bus line system.

[0136] The higher-level control unit controls, in particular, the battery testing equipment or, more generally, the test stations with their charging and discharging processes. The control unit ensures, in particular, that the power demand caused by charging battery units and the power supply resulting from discharging battery units are balanced as much as possible. In the event of an imbalance between power supply and power demand, the control unit ensures, in particular, that this imbalance is compensated by the buffer battery.

[0137] The central control device temporally controls the charging and discharging processes of the battery units in the battery pool, particularly in such a way that the demand for electrical energy from the bus line system, in particular for charging processes, and the supply of electrical energy from discharging processes for feeding into the bus line system are balanced as much as possible. According to a further development, the electrical energy required to operate at least one electrical consumer or device of the device according to the invention is also obtained directly or indirectly from the bus line system, as explained above. This means that the at least one electrical consumer is supplied with electrical energy released by discharging processes of battery units in the battery pool.

[0138] The electrical consumer can be connected to the BUS line system via a separate cable connection and, if necessary, via a separate power converter.

[0139] The electrical consumers of the device can be power converters, charging and discharging devices, battery testing devices or the buffer battery.

[0140] However, it can also be provided that the at least one said device of the device draws its electrical energy from the public power grid or from another buffer battery.

[0141] According to a further development, the device contains a power converter, in particular an inverter (e.g. AC / DC converter), via which the BUS line system can be connected to the public power grid, so that when battery units of the battery pool are discharged, the released, in particular surplus, electrical energy can be fed into the public power grid.

[0142] According to a further development, the device contains a power converter, in particular a rectifier, via which the bus line system can be connected to the public power grid, so that electrical energy for charging battery units of the battery pool can be drawn from the public power grid. It can also be provided that, in the manner described above, electrical energy for operating at least one electrical consumer of the device can be drawn from the public power grid.

[0143] The said power converter is designed in particular as a bidirectional interface to the public power grid or as a bidirectional inverter and in particular includes the function of both an inverter and a rectifier.

[0144] In a further development, it can be provided that the battery testing equipment or the higher-level control device compares the measurement data with stored data, such as threshold values, and assigns the battery units to a condition category on the basis of this comparison.

[0145] By means of the device according to the invention, battery units of different types can be tested, categorized according to battery condition and, if necessary, prepared for recycling.

[0146] For this purpose, the device may comprise a (central) database.

[0147] For each battery type, the corresponding threshold values ​​for categorizing the battery units based on the determined battery status information can be stored in the database.

[0148] The stored data can also include measurement data from other battery units of different battery types that have already been assigned to a condition category. For example, the database can contain measurement data transmitted by an evaluation device, for example, for a large number of battery units or battery types, each of which is assigned to a condition category. By comparing the measured values ​​with the measured values ​​recorded in the database for battery units of a specific battery type, the evaluation device can assign the battery to a condition category accordingly.

[0149] The categorization of battery units based on measurement data acquired by a test device can be supported by machine learning algorithms. This allows the battery units to be tested using multiple test methods, such as EIS or capacity measurement, with the evaluation device using measurement data from one test method, e.g., capacity measurement, to interpret the measurement data from the other test method, e.g., EIS. The interpretation of the measurement data is part of the categorization of the battery units. In this way, the evaluation device continuously improves the interpretation of the measurement data from the other test method, such as EIS. The corresponding measurement data and the associated categorization are stored in the database and are used for future categorization of battery units.

[0150] The database can also contain stored battery test programs for the various battery types. If the battery type is known, the corresponding battery test program can be retrieved and executed from the database. The battery test programs specify, for example, which test method is used to test the battery. Furthermore, the battery test programs can also contain test parameters for the corresponding battery type.

[0151] The battery test programs or the corresponding test parameters for the individual battery types can also be stored in the database.

[0152] Furthermore, the database can also contain stored discharge programs or the associated discharge parameters for the various battery types. The discharge program is used to discharge the battery units after battery testing as part of the recycling preparation process and, for example, to transfer them to a charge level suitable for recycling. The database can, for example, be part of a higher-level process software, such as ERP (Enterprise Resource Planning) software, which digitally maps the stored battery preparation processes, such as battery testing, categorization, and battery discharge (recycling preparation). This means that the higher-level process software guides the user through the individual process steps.

[0153] The process software is therefore specifically designed to digitally map the entire battery preparation process, from battery testing through battery categorization to the discharging of the battery units (recycling preparation).

[0154] The process software can also be designed to obtain individual battery data from a digital battery passport and / or from the BMS and, in particular, to store it in the central database and to take it into account during the battery testing.

[0155] The battery passport and / or BMS contain data about the batteries, such as:

[0156] - Operating data, such as charging and discharging cycles, temperature profiles, and events such as overcharging or deep discharging;

[0157] - Usage data, e.g. the number of charging cycles, maximum charging and discharging currents, charging times, as well as information on chemical aging or capacity loss;

[0158] - Maintenance and contingency data, such as repairs, damage or unusual operating conditions that may have affected the battery life and performance;

[0159] - Technical data, such as battery type, about the battery. The battery data stored in the database can provide information about the battery's condition even before the battery test begins.

[0160] The data on the battery units stored in the database, e.g., data read from a battery management system (BMS), data read from a digital battery passport, manually entered data and / or (measurement) data from the test carried out within the scope of the method according to the invention, can be used to optimize the testing and categorize the battery units.

[0161] The (historical) battery data stored in the database can be used as training data in machine learning based on artificial intelligence. This is achieved through the use of so-called "machine learning models." By using such a pre-trained model, the categorization of battery units can be optimized based on historical data from previously tested and categorized battery units.

[0162] For example, algorithms can be designed to derive patterns from the (historical) battery data stored in the database, allowing conclusions to be drawn about the state of health (SOH) of a battery unit. The algorithms can thus detect patterns in the battery data that indicate hidden defects, aging, or imminent deterioration of the battery unit, even before this can be detected through direct measurements in the test procedure.

[0163] With the method according to the invention and the associated device, database-supported, individual test programs can be compiled for the individual battery units depending on the initial state of charge (SOC).

[0164] For example, a pre-trained artificial intelligence (AI) model based on (historical) battery data from the central database can be used to perform a predictive (preliminary) assessment of the overall health (SOH). This can include how well the battery unit is currently performing and how its condition might develop.

[0165] Furthermore, pre-trained AI models based on (historical) battery data from the central database can detect battery faults such as internal short circuits, cell failures, or uneven cell aging without the need for a charge or discharge cycle or battery testing. This helps optimize and accelerate the testing process, as batteries with already identified defects can be directly classified into the "recycling" category without further testing.

[0166] Furthermore, pre-trained AI models can be used to automatically adjust test parameters based on (historical) battery data from the central database. This allows test parameters to be automatically adjusted based on the predictive (preliminary) assessment of the overall health (SOH) performed using the AI ​​model. For example, a battery with impaired SOH could undergo shorter charge and discharge cycles to accelerate the test process. Batteries with good SOH, on the other hand, could be subjected to a more extensive test program to more accurately determine reusability.

[0167] The higher-level process software can therefore perform customized parameterization for individual battery types or battery units based on stored data for the individual battery types and, if applicable, for the individual battery units themselves. During parameterization, the test programs or test parameters for the individual battery units are defined.

[0168] Accordingly, the battery testing devices communicate with the higher-level

[0169] Process software. The higher-level process software or specific applications from this software can be executed by the higher-level or central control device.

[0170] The database is integrated into a cloud system, which is accessed via a HTTPS connection, for example. This has the advantage that additional groups of people or additional recycling locations can access, maintain, and manage the database.

[0171] The process software, including the database, can be part of a cloud computing system that provides device-independent data, software applications, or programs such as test programs and can be accessed, for example, via an internet connection. The aforementioned higher-level or central control device is specifically integrated into the cloud computing system.

[0172] According to a further development, the battery testing devices are designed and configured in such a way that they can communicate with the BMS (battery management systems) of different battery types. This allows for efficient condition testing of the corresponding batteries in the battery pool. This means that the battery testing device is particularly compatible with different manufacturers' BMS systems.

[0173] This allows for controlled charging and / or discharging of the battery via the BMS. Alternatively, the battery tester itself can contain a universal BMS, which can be used to charge and / or discharge the batteries in a controlled manner.

[0174] According to a further development, the device can contain a battery detection device, by means of which the battery type of the battery unit is determined. The battery detection device can be part of the battery testing device. The battery testing device can execute a test program adapted based on the determined battery type, in particular with at least one charging and discharging cycle. The test programs for the individual battery types can be stored in a database and called up by the battery testing device.

[0175] The battery type can be identified automatically using the battery detection device, for example by querying the BMS or by reading the battery passport using the battery detection device.

[0176] The battery type can also be read from an information carrier attached to the outside of the battery, such as a QR code. Battery identification can also be performed by a user entering the battery type (operator input).

[0177] The test programs and test parameters, as well as the discharge programs and discharge parameters, associated with individual battery types can be stored in a (central) database. After determining the battery type, the battery testing device can retrieve the corresponding test program and discharge program for the determined battery type via a database comparison.

[0178] A battery pool can therefore comprise battery units of different battery types. Since the bus line system operates with a standardized, i.e., synchronized, voltage, the output voltage of the individual battery types plays a subordinate role. The battery types can differ in terms of their nominal voltages, capacities, and / or battery chemistries.

[0179] It can also be provided that the battery units of the battery pool are both batteries and individual (battery) cells. As mentioned, the battery pool contains a large number of battery units and therefore a corresponding number of battery connections. The larger the number of battery units in the battery pool, the more efficient the distribution of electrical energy between the battery units being discharged and the battery units being charged via the bus line system. In particular, the flow of electrical energy is more balanced with a large number of battery units in the battery pool.

[0180] The device according to the invention is designed in particular so that it can be expanded as required with additional test stations with corresponding battery connections. To do so, additional battery connections simply need to be connected to the BUS line system and, if necessary, registered with the higher-level control system.

[0181] Thanks to the method according to the invention, batteries of different voltages, i.e. independent of the voltage, can be charged and discharged for testing purposes, categorized and brought into a state suitable for recycling by a final discharge in a common device.

[0182] Thanks to bidirectional energy management, in which electrical energy released by discharging batteries in the battery pool is fed into an internal bus line system to charge other batteries in the battery pool and, if necessary, to operate the device's equipment, essentially grid-independent operation of the device is possible. The bus line system thus corresponds to a type of island network.

[0183] The device according to the invention is also not dependent on a specific battery testing method. The device allows the use of various battery testing methods at different battery preparation or testing stations. Furthermore, the device can also be operated with new or modified testing methods. The battery testing equipment only needs to be equipped accordingly.

[0184] The device according to the invention is fundamentally independent of a specific battery testing device. The device allows the use of various battery testing devices at different battery preparation stations or testing stations.

[0185] The subject matter of the invention is explained in more detail below with reference to the accompanying figures. They show schematically:

[0186] Figure 1: a conceptual scheme for testing and categorising battery

[0187] units;

[0188] Figure 2: a connection diagram for a device according to the invention;

[0189] Figure 3: an energy flow diagram for bidirectional energy management;

[0190] Figure 4: a process diagram;

[0191] Figure 5: a connection diagram of a battery cell connection device.

[0192] In principle, identical parts are provided with identical reference numerals in the figures. For a better understanding of the invention, certain features are not shown in the figures or are shown only in a highly abstract manner. The exemplary embodiments described below are merely examples of the subject matter of the invention.

[0193] The device 6 according to the invention forms a battery pool 2 for testing and categorizing as well as for preparing a plurality of batteries 1 for recycling.

[0194] According to the conceptual diagram in Figure 1 and the connection diagram in Figure 2, decommissioned or discarded batteries 1' are added to the battery pool 2 of the device 6 by connecting them to a bus line system 10 via a DC-DC converter 16. The bus line system 10 is operated with a defined DC voltage. A battery connection 7 is provided for connecting each battery 1' in the battery pool 2.

[0195] The batteries 1' come, for example, from electrical consumers, such as vehicles 4.1, or storage devices 4.2 for photovoltaic systems.

[0196] A battery testing device 14 for testing the batteries 1 and a charging and discharging device 15 for performing charging and discharging steps are arranged between the battery terminals 7 and the DC-DC converter 16 (see Figure 2). The battery terminal 7, the battery testing device 14, the charging and discharging device 15, and the DC-DC converter 16 are part of a battery preparation station or testing station 17, or constitute such a station.

[0197] The battery testing device 14 and the charging and discharging device 15 can be combined into a functional unit.

[0198] The BUS line system 10 is connected to the public power grid 20 via a bidirectional inverter 12, which enables the purchase of electrical energy from the public power grid or power supply network 20 and the feeding of electrical energy into the public power grid 20.

[0199] Furthermore, a buffer battery 11 is connected to the BUS line system 10, the nominal voltage of which corresponds to the standardized voltage in the BUS line system 10.

[0200] Batteries 1' with an unknown state of charge (SOC) and an unknown general condition (SOH), which are newly added to battery pool 2, are assigned to a testing and categorization group 3 within battery pool 2. The state of charge (SOC) and the general condition of the battery (SOH) must be determined.

[0201] Testing and categorization group 3 now contains, in a snapshot, batteries 1.1 that are currently being tested, as well as batteries 1.2 and 1.3 that have already been tested and categorized. Of the tested and categorized batteries 1.2 and 1.3, a first portion of batteries 1.2 is assigned to the "Recycling" category, and a second portion of batteries 1.3 is assigned to the "Reuse" category. Batteries 1.2 in the "Recycling" category are reclassified from testing and categorization group 3 to recycling (discharging) group 5. Batteries 1.3 in the "Reuse" category can be removed from battery pool 2 after they have been brought to a specified charge level, if necessary.

[0202] As part of the battery test, the first step is to determine the battery type of the batteries 1.1 to be tested from test and categorization group 3. The batteries 1.1 are then subjected to a referencing test, particularly by complete charging or discharging. Depending on the charge level of the batteries 1' installed, the batteries 1.1 are charged or discharged for referencing purposes. This means that batteries 1.1 with a comparatively high charge level are charged for referencing purposes, and batteries 1.1 with a comparatively low charge level are discharged for referencing purposes.

[0203] The reference batteries 1.1 are then subjected to a test program and checked for their general condition. The test process or test procedure includes at least one charging and / or discharging process, in particular one or more charging and discharging cycles.

[0204] The goal of battery testing is to determine battery condition information, or SOH (state of health), which allows the battery to be categorized into at least one of the two categories "reuse" and "recycling." Batteries 1.2 in the "recycling" category are reassigned from testing and categorization group 3 to recycling group 5 for discharging. Allocation to or between groups is not physical but virtual, as part of the bidirectional energy management within battery pool 2.

[0205] Batteries 1.4 of recycling (discharging) group 5 are discharged to a final discharge voltage via the charging and discharging device 15 in preparation for recycling. The energy released by discharging batteries 1.4 of recycling (discharging) group 5 is fed into the bus line system 10. The electrical energy 30 released by discharging batteries 1.4 of recycling (discharging) group 5 is then used to charge batteries 1.1 of test and categorization group 3. Excess electrical energy 32 released by discharging batteries 1.4 of recycling (discharging) group 5 can be fed into the public power grid 20 or used to charge a buffer battery 11 (see Figure 1).

[0206] A central, higher-level control device 40 of the device 6 controls the current flow in the bus line system 10. The control of the current flow is designed so that as little electrical energy as possible needs to be fed into and drawn from a buffer battery 11 or a public power grid 20. Accordingly, the control device 40 controls the charging and discharging processes of the batteries 1.1, 1.4 such that the supply of electrical energy and the supply of electrical energy in the bus line system 10 are as balanced as possible.

[0207] The control device 40 is particularly designed to retrieve test programs, threshold values, test parameters, and / or discharge programs from a database 41, e.g., by means of higher-level process software. If there is an excess demand for electrical energy from test and categorization group 3, additional electrical energy 31 can be drawn from the public power grid 20 or from the buffer battery 11.

[0208] Furthermore, it is provided that the electrical energy released during referencing or battery testing by discharging batteries 1.1 of test and categorization group 3 is fed into the bus line system 10 and used to charge other batteries 1.1 of test and categorization group 3.

[0209] The electrical energy fed into the bus line system 10 is converted by the DC-DC converters 16 into the standardized voltage of the bus line system 10. Conversely, the electrical energy drawn from the bus line system 10 for charging batteries 1.1 of the battery pool 2 or the test and categorization group 3 is converted by the DC-DC converters 16 into the nominal voltage of the batteries 1.1 or into an operating voltage.

[0210] As mentioned, excess electrical energy from discharging batteries 1.1, 1.4 of battery pool 2 can be stored via the buffer battery 11 and later released to charge batteries 1.1 of battery pool 2 or test and categorization group 3. By temporarily storing excess electrical energy in the buffer battery 11, independence from the public power grid 20 can be further increased.

[0211] Batteries 1.4 from recycling group 5 that have been discharged to their final discharge voltage, as well as batteries 1.3 from test and categorization group 3 that are assigned to the "reuse" category, are removed from battery pool 2 and recycled or reused (see Figure 1). According to Figure 1, batteries 1.3 in the "reuse" category are further divided into the two subcategories "full reuse" and "partial reuse."

[0212] Depending on the quality of the reusable batteries 1.3 or cells, these can be used for vehicles 4. 1 or as stationary batteries.

[0213] The vacant battery spaces or the battery preparation stations or test stations can be filled again with new, decommissioned batteries 1'.

[0214] The energy flow diagram shown in Figure 3 shows three batteries in a battery pool whose state of charge (SOC) and general condition (SOH) are unknown. Battery 1' is newly added to battery pool 2. The two upper batteries, 1.1, 1.1', are already in battery pool 2 and are being tested.

[0215] The first battery 1.1 from battery pool 2 has a comparatively high terminal voltage, indicating a relatively high charge level. Accordingly, this battery 1.1 is fully charged by the battery testing device for reference purposes. The battery state of health (SOH) or battery status information is then determined using a test program executed by the battery testing device. In this case, the battery status is positive, and the first battery is assigned to the "Reuse" category. The first battery 1.1 is then brought to a charge level suitable for storage.

[0216] The second battery 1.1' has a comparatively low terminal voltage, indicating a relatively low charge level. Accordingly, battery 1.1' is completely discharged by the battery testing device for reference purposes. The electrical energy released when discharging the second battery 1.1' for reference purposes is then fed into the BUS line system and used to charge the first battery 1.1 for reference purposes.

[0217] Subsequently, the battery state of health (SOH) or battery status information for the second battery 1.1' is determined using a test program executed by the battery testing device. In this case, the battery status is negative, and the second battery 1.1' is assigned to the "Recycling" category. Accordingly, following the battery test, i.e., after categorization, the second battery 1.1' is discharged to a final discharge voltage in preparation for recycling.

[0218] The third battery 1', which will be added to battery pool 2 later, also has a comparatively high terminal voltage, indicating a relatively high charge level. Accordingly, the third battery 1' is fully charged for reference purposes by the battery testing device. The electrical energy released when the second battery 1.1', which has already been categorized, is discharged to the final discharge voltage for recycling preparation is then fed into the bus line system and used to charge the third battery 1' for reference purposes.

[0219] The process diagram shown in Figure 4 shows the processes carried out in connection with the inspection or testing, categorisation and recycling preparation of lithium-ion batteries.

[0220] Initially, the battery type is determined using a battery detection device. This can be done, for example, by querying the battery's BMS (Battery Management System), by reading an information carrier on the battery, by manual entry, or by querying a digital battery passport from a database. Battery detection can be performed before the battery is added to the battery pool. However, battery detection is preferably performed in the battery pool. The battery detection device can be part of the battery testing device or a separate device.

[0221] If the battery type cannot be determined, the battery in question will be excluded from the categorization and recycling preparation process or removed from the battery pool.

[0222] According to the present invention, batteries of a known battery type are subjected to testing, categorization, and, if necessary, recycling preparation in the battery pool, as described in Figures 1 to 3. In particular, the bidirectional energy management system according to the invention, as described above, is also used here.

[0223] Before the actual battery test, a voltage test is performed. Batteries that fail to meet specified criteria or reach specified thresholds during the voltage test are assigned to the "recycling" category without further testing. Such batteries are damaged, for example, by deep discharge or a short circuit and cannot be recharged.

[0224] Based on the determined SOH (state of health) or the determined battery condition information, the battery is assigned to one of three categories: "recycling", "(complete) reuse" or "partial reuse".

[0225] The data generated during the testing process, such as information on battery condition and measured values, test programs, test parameters, etc., are stored in a database and can be used for traceability and subsequent battery testing using machine learning. Batteries in the "Recycling" category are discharged to their final discharge voltage in the battery pool and then sent to a recycling process.

[0226] Batteries in the "Reuse" category are intended for reuse, e.g., as stationary batteries.

[0227] Batteries in the "partially reused" category are opened, and the cells inside are removed. The reusable cells are recycled, for example, into newly assembled batteries. The non-reusable cells are recycled (see also Figure 1).

[0228] Figure 5 shows a battery cell connection device 59 such as may be provided on a battery preparation station 58. The battery preparation station 58 contains a battery connection 57, which is connected via a power connection channel to a bus line system, as shown, for example, in Figure 2. The battery connection 57 may correspond to the battery connection 7 shown in Figure 2.

[0229] The battery preparation station 58 contains a testing device and / or charging / discharging device 50, which is equipped with a station control unit 51. The testing device and / or charging / discharging device 50 can correspond to the battery testing device 14 or charging and / or discharging device 15 according to Figure 2.

[0230] The battery cell connection device 59 comprises a power supply line 54, which is connected to the battery connection 57. A plurality of cell control units 52.1-52.n are arranged in series on the power supply line 54. Each cell control unit 52.1-52.n has a battery cell connection 55 for connecting a respective battery cell 53.1-53.n. The cell control units 52.1-52.n are connected to the station control unit 51 via a communication line or data line 56. The communication line or data line 56 is designed as a BUS system. The station control unit 51 controls and monitors the cell control units 52.1-52.n, particularly as a higher-level control unit.

[0231] The battery preparation station or test station 58 is designed so that for testing or discharging purposes, either a battery or a battery module can be connected via the battery connection 57 or individual battery cells 53.1-53.n can be connected via the battery cell connections 55 of the battery cell connection device 59 to the battery preparation station or test station 58.

[0232] The cell control units 52.1-52.n serve to individually control at least one charging and / or discharging process of the individual battery cells 53.1-53.n as part of a cell test or as a recycling preparation step for a subsequent recycling process. However, the battery cell connection device 59 is designed specifically for the individual discharging of individual battery cells 53.1-53.n.

[0233] The cell control units 52.1-52.n control at least one charging and / or discharging process or, if necessary, the testing of the individual battery cells 53.1-53.n. Thus, the connected battery cells 53.1-53.n can have different states of charge (SOC). The cell control units 52.1-52.n control the state of charge of the battery cells 53.1-53.n, in particular via the battery cell voltage 53.1-53.n. If a battery cell 53.1-53.n has reached a predetermined state of charge and is discharged to a final voltage, for example, the respective battery cell 53.1-53.n is bridged by the respective cell control unit 52.1-52.n. For this purpose, the cell control unit 52.1-52.n has a bridging device 60 for bridging the battery cell connection 55 to the relevant battery cell 53.1-53.n can be disconnected from the battery cell connection during operation and a new battery cell can be connected - also during operation.

Claims

PATENT CLAIMS 1. Method for testing and preparing battery units for recycling, in particular lithium-ion battery units (1.1), wherein several battery units (1.1-lx) are combined in a battery pool (2) and connected to one another via a BUS line system (10) for exchanging electrical energy.

2. Method according to claim 1, characterized in that battery units (1.1-1x) of the battery pool (2) are charged and / or discharged for the purpose of battery testing and / or recycling preparation, wherein electrical energy released by the discharging of at least one battery unit (1.2) of the battery pool (2) is used via the BUS line system (10) to charge at least one other battery unit (1.1) of the battery pool (2).

3. Method according to claim 1 or 2, characterized in that at least one battery unit (1.1) of the battery pool (2) is made referential during the battery test by at least one charging process, wherein the at least one battery unit (1.1) is charged via the BUS line system (10) with electrical energy released by discharging at least one other battery unit (1.2) of the battery pool (2).

4. Method according to one of claims 1 to 3, characterized in that battery status information is determined for at least one battery unit (1.1) of the battery pool (2) as part of the battery test by means of at least one charging process or charging and discharging cycle, wherein the at least one battery unit (1.1) is charged via the BUS line system (10) with electrical energy released by discharging at least one other battery unit (1.2) of the battery pool (2).

5. Method according to one of claims 3 to 4, characterized in that the at least one battery unit (1.1) is charged with electrical energy which is released by discharging at least one other battery unit (1.2) of the battery pool (2) as part of a referencing of the at least one other battery unit (1.2).

6. Method according to one of claims 3 to 4, characterized in that the at least one battery unit (1.1) is charged with electrical energy which is released by discharging at least one other battery unit (1.2) of the battery pool (2) during at least one discharging process or charging and discharging cycle of the battery test for the purpose of determining battery status information.

7. Method according to one of claims 3 to 4, characterized in that the at least one battery unit (1.3) is charged with electrical energy which is released by discharging at least one other battery unit (1.2) of the battery pool (2) for the purpose of preparing for recycling.

8. The method according to one of claims 1 to 7, characterized in that at least one electrical consumer (12, 14, 15, 16), such as battery testing device (14), charging and discharging device (15) and / or power converter (12, 16) of the device (6) is operated via the BUS line system (10) with electrical energy released by discharging at least one battery unit (1.2) of the battery pool (2), wherein the electrical energy is released in particular: by discharging at least one battery unit (1.2) of the battery pool (2) as part of a referencing of the at least one battery unit (1.2); - is released by discharging at least one battery unit (1.2) of the battery pool (2) during at least one discharging process or charging and discharging cycle of the battery test for the purpose of determining battery status information, and / or - is released by discharging at least one battery unit (1.2) of the battery pool (2) for the purpose of recycling preparation.

9. Method according to one of claims 1 to 8, characterized in that the battery units (1.1, 1.x) supplied to the battery pool (2) are each connected to a battery testing device (14) via a battery connection (7) and tested, and, in particular by means of at least one charging and discharging cycle, battery condition information is determined, and the battery units (1.1-1.x) are divided into the at least two condition categories "reuse" and "recycling" on the basis of the battery condition information, and battery units (E I'-1.x') of the condition category "recycling" are discharged to a final voltage suitable for the recycling process.

10. Method according to one of claims 1 to 9, characterized in that battery status information is determined by means of the battery test, and the battery status information is used to assign the battery units (1.1-1.x) to one of at least two status categories.

11. Method according to one of claims 1 to 10, characterized in that the BUS line system (10) is operated with a standardized DC voltage, wherein the electrical energy is converted from the standardized DC voltage, in particular via DC voltage converters (16), which are each arranged between the battery terminals (7) and the BUS line system (10). is converted to the respective nominal voltage of the battery units (1.1-1. x) and vice versa.

12. Method according to one of claims 1 to 11, characterized in that the battery units (1.1-1x) of the battery pool (2) to be checked for their condition are assigned to a test group (3) and the battery units (1.1'-1.x') checked and assigned to a condition category "recycling" are assigned to a recycling group (5), and by discharging battery units (1.1'-1x 1 ) of the recycling group (5) for the purpose of recycling preparation, electrical energy released is used to charge battery units (1. 1-lx) of the test group (3) (11).

13. Method according to one of claims 1 to 12, characterized in that at least one or more of the following categories of data are recorded in a database (41): - Data on battery units, such as technical data, operating data, maintenance data or status data, which are read in from an external data source, such as a digital battery passport or a BMS (Battery Management System); - Data such as battery test programs or test parameters required for testing and / or categorising battery units, - Data, in particular measurement data, which are determined during the testing of battery units; - Data such as the condition category resulting from the categorization of the battery units, and in particular an automated testing and / or categorization of the battery units of the battery pool (2) by evaluating data recorded in the database (41).

14. The method according to one of claims 1 to 13, characterized in that data on battery units (1. l'-l.x') in the battery pool (2), in particular on tested and categorized battery units (1. l'-l.x'), are stored in a database (41), and a machine learning model 11 is trained with the stored data, and the trained machine learning model is used for the automated categorization of the battery units (1. l'-l.x'), in particular into the categories "reuse" and "recycling".

15. Method according to one of claims 1 to 14, characterized in that the battery units (1.1-lx) are tested by means of a battery testing device (14), wherein the battery testing device (14) executes a test program dependent on the battery type, and wherein the test programs or the associated test parameters are stored in a database (41) and are retrieved from this, and wherein the database (41) is in particular integrated into a cloud system which can be accessed, for example, via an internet connection.

16. Method according to one of claims 1 to 15, characterized in that the battery units (1.1-lx) are discharged for recycling preparation by means of a discharge program dependent on the battery type, wherein the discharge programs or the associated discharge parameters are stored in a database and are retrieved from this, and wherein the database (41) is in particular integrated into a cloud system which can be accessed, for example, via an internet connection.

17. Method according to one of claims 1 to 16, characterized in that the overall process of battery preparation, comprising in particular the battery testing, the categorization and the discharging of the battery units for recycling preparation, is digitally mapped by means of a higher-level process software.

18. Device (6) for carrying out the method according to one of claims 1 to 17, characterized by a BUS line system (10) for the purpose of exchanging electrical energy between the battery units (1.1-1.x) of the battery pool (2), wherein the device (6) contains a plurality of battery terminals (7) for connecting battery units (1.1-1x) to the BUS line system (10).

19. Device according to claim 18, characterized in that a power converter (16), in particular a DC voltage converter, is arranged between the battery terminals (7) and the BUS line system (10) for the purpose of converting the voltage, in particular the DC voltage, between the battery units (1.1-1x) and the BUS line system (10).

20. Device according to claim 19, characterized in that a charging and discharging device (15) for charging or discharging the battery units (1.1-1x) is arranged between the battery terminals (7) and the power converters (16).

21. Device according to one of claims 19 to 20, characterized in that a battery testing device (14) for determining battery status information is arranged between the battery terminals (7) and the power converters (16).

22. Device according to one of claims 18 to 21, characterized in that the device (6) comprises a control device (40) and a database (41) connected thereto for storing and retrieving data, such as battery test programs or test parameters for different battery types, which are required for the testing and / or categorization of battery units.

23. Device according to one of claims 18 to 22, characterized by at least one battery cell connection device (59) which is connected to the BUS line system (10) via a battery connection (57), and a plurality of cell control units (52.1-52.n) each having a Battery cell connector (55) for connecting individual battery cells (53.1-53.n).

24. Device according to one of claims 18 to 23, characterized in that the device contains a plurality of battery preparation stations (17, 58), each forming a station control unit (51) and a battery connection (7, 57), and the station control units (51) are connected to the control device (40) via communication or data lines.

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