Battery pack and battery system

Abstract

The invention relates to a battery pack for detachable electrical connection to a battery device, said battery pack having at least one substantially cylindrical electrical battery cell for storing electrical energy, and a current limiting device which is designed separately from the at least one battery cell and is electrically connected to the battery cell, the current limiting device is used for limiting current flowing between the at least one battery unit and the battery equipment; wherein the at least one battery cell has a cell interior and a differential pressure valve, and wherein the differential pressure valve is configured to control the at least one battery cell if a prevailing pressure difference between the cell interior and an environment outside the battery cell exceeds a predetermined limit value. If the at least one battery cell does not have a current interruption device and / or a current limiting device, the cell interior is automatically connected to the external environment in a pressure-dependent manner, and the at least one battery cell itself does not have a current interruption device and / or a current limiting device.

Description

Field of the Invention

[0001] The present invention relates to a battery pack for detachably electrically connecting to a battery device. The present invention also relates to a battery system having such a battery pack. Summary of the Invention

[0002] The object of the present invention is to create a battery pack for detachably electrically connecting to a battery device and a battery system having such a battery pack, which in particular each have improved characteristics.

[0003] This object is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims.

[0004] A battery pack according to the present invention, in particular an electrical battery pack, is intended for detachably electrically connecting to a battery device, in particular and detachably mechanically connecting. The battery pack can be configured for use in a battery system including the battery pack and the battery device. The battery pack is in particular configured to store electrical energy.

[0005] The battery pack has at least one substantially cylindrical battery cell for storing electrical energy. In addition, the battery pack has a current limiting device, in particular for at least limiting the current flowing between at least one battery cell and the battery device, wherein the current limiting device is configured separately from at least one battery cell and is in particular directly or indirectly electrically connected to the battery cell. In particular, the current limiting device and at least one battery cell are constructed non-uniformly. At least one battery cell and the current limiting device can be configured to be locally separated from each other and / or locally arranged differently, in particular arranged spaced apart from each other. In particular, the current limiting device is arranged outside at least one battery cell. Suitably, if there is an internal and / or external electrical short circuit of the battery pack and alternatively or additionally if the temperature of the battery pack exceeds a predetermined temperature value and alternatively or additionally if the internal pressure exceeds a predetermined pressure value, the current can be limited by means of the current limiting device, in particular wherein the battery pack has a sensor device in control connection with the current limiting device for detecting a short circuit and / or temperature and / or internal pressure.

[0006] At least one battery cell has a cell internal space and a differential pressure valve. Here, the differential pressure valve is configured to automatically connect the cell internal space to the external environment of the battery cell in a pressure-coordinated manner when the dominant pressure difference between the cell internal space and the external environment exceeds a predetermined limit value.

[0007] At least one battery cell itself does not have a current limiting device and, alternatively or additionally, does not have a current interrupting device. Thus, the current limiting device of the battery pack can be accessible, for example, for repair and / or maintenance purposes of the battery pack without the need to access at least one battery cell. From a sustainability perspective, this can bring advantages. The manufacture and / or procurement of at least one battery cell can be particularly expensive. By separating the current limiting device from the battery cell, the current limiting device can be realized when necessary, especially without affecting the battery cell.

[0008] Suitably, the differential pressure valve is configured not to limit and, alternatively or additionally, not to interrupt the current.

[0009] Suitably, the pressure difference corresponds to the difference between the prevailing internal pressure in the unit interior space and the prevailing ambient pressure in the external environment. In particular, the differential pressure valve is specifically configured for a pressure-coordinated connection between the unit interior space and the external environment. In particular, the differential pressure valve is configured to connect the unit interior space and the external environment in a pressure-coordinated manner when the internal pressure is greater than the ambient pressure, especially only when the internal pressure is greater than the ambient pressure. In this regard, the differential pressure valve can thus act as a pressure relief valve. In particular, the differential pressure valve is configured to irreversibly and pressure-coordinatedly connect the unit interior space and the external environment, i.e., the differential pressure valve cannot be re-closed after opening and / or is damaged when it is open.

[0010] In this context, "substantially cylindrical" can take into account the presence of chamfers and, alternatively or additionally, the presence of rounding at the transition between the end side of the substantially cylindrical battery cell and the side surface of the battery cell, especially a circumferential and / or edge-like transition. Alternatively or additionally, "substantially cylindrical" can take into account the presence of unevenness and / or contour on at least one end side of the battery cell. "Substantially cylindrical" can take into account a spherical shape, especially a spherical shape of the side surface.

[0011] In this context, "substantially cylindrical" can especially, alternatively or additionally, refer to the shape of a general cylinder. Thus, it is conceivable that a substantially cylindrical battery cell, for example, has a substantially prismatic shape, especially a cuboid shape. A substantially cylindrical battery cell preferably has a substantially cylindrical shape. A substantially cylindrical battery cell can be synonymously referred to as a "round battery cell". In particular, a substantially cylindrical battery cell is not a pouch-type battery cell.

[0012] Suitably, at least one battery cell does not have a "Current Interrupt Device (CID)". In particular, such a CID exists as a current interruption device in a conventional cylindrical battery cell, especially an integrated and / or non-removable one. The CID of a conventional cylindrical battery cell is particularly configured to irreversibly limit, especially interrupt, the current, i.e., once the CID is triggered to limit the current once, the CID loses its function and / or is irreversibly damaged. In particular, in the case of a conventional battery cell, the triggering of an integrated, especially inseparably integrated, CID causes the entire battery cell to become unusable and / or irreversibly damaged, so that the entire conventional battery cell must be replaced. In this regard, dispensing with the integrated CID can have a beneficial impact on the sustainability of the battery pack, especially since it is not necessary to replace the entire at least one battery cell after the current has been limited. Dispensing with the CID of the battery cell can also have a beneficial impact on the electrical battery cell impedance of the battery cell.

[0013] It is conceivable that the battery pack can have at least one or exactly one battery cell without a CID and at least one or exactly one other battery cell with a CID. However, preferably, none of the battery cells in the battery pack have a CID.

[0014] The term "configured" or "set" can be used synonymously with the term "constructed".

[0015] The term "comprising" or "having" can be used synonymously with the term "possessing".

[0016] In this context, "control" can mean "control" and / or "regulation".

[0017] The phrase "and alternatively or additionally" can be equivalently replaced by "and / or".

[0018] Suitably, the current limiting device is arranged in the electrical positive path of the battery pack and alternatively or additionally arranged in the electrical negative path of the battery pack. Thus, the current limiting device can be arranged only in the positive path or only in the negative path or in both the negative path and the positive path.

[0019] Suitably, the current limiting device can be especially alternatively or additionally arranged in the electrical connection path of the battery pack, where the electrical connection path connects at least two battery cells of the battery pack to each other.

[0020] Suitably, the connection path can electrically connect at least two battery cell groups to each other, especially where these battery cell groups are electrically connected in parallel or in series by means of the connection path. The battery cells belonging to a group can be electrically connected in series or in parallel with each other within the group.

[0021] Suitably, at least one battery cell has a cell housing which, together with the differential pressure valve, delimits a cell interior space. When the differential pressure valve is closed, the cell interior space can be separated from the external environment in a fluid-tight manner by means of the cell housing and by means of the closed differential pressure valve.

[0022] Suitably, the external environment of the battery cell is present in the housing interior space of the battery pack which is surrounded by the battery pack housing of the battery pack. In particular, the housing interior space is in fluid-conductive and alternatively or additionally pressure-equalizing communication with the atmosphere surrounding the battery pack.

[0023] Suitably, the current limiting device can have a housing, in particular its own housing, wherein the housing of the current limiting device and the cell housing of at least one battery cell are constructed to be non-uniform in material and / or physically different from each other. The battery pack housing of the battery pack can form and / or in particular integrally have the housing of the current limiting device.

[0024] In a design of the present invention, at least one battery cell has an electrical battery cell impedance. Here, when an alternating current with an alternating current frequency of 1 kHz is applied, the value of the battery cell impedance is less than 10 mΩ (milli-ohm) when the state of charge (SOC) of the battery cell is 50% and when the temperature of the battery cell is between 20 °C and 25 °C. In particular, for this value of the battery cell impedance, only the real part of the battery cell impedance is considered, in particular the imaginary part is not considered. In particular, when an alternating current with an alternating current frequency of 1 kHz is applied, the value of the electrical battery cell impedance is in particular less than 5 mΩ, in particular less than or equal to 3 mΩ when the state of charge is 50% and the temperature is between 20 °C and 25 °C.

[0025] In particular, when an alternating current with an alternating current frequency of 1 kHz is applied, the value of the electrical battery cell impedance of the battery cell is greater than 0.1 mΩ, in particular greater than 0.5 mΩ, in particular greater than 1 mΩ, in particular greater than 2 mΩ when the state of charge of the battery cell is 50% and the temperature of the battery cell is between 20 °C and 25 °C.

[0026] Suitably, the 50% state of charge can be determined as follows: The battery cell can be charged to a predetermined nominal voltage, in particular the nominal voltage defined by the manufacturer, wherein the nominal voltage corresponds to a 50% state of charge. Alternatively or additionally, the battery cell can first be fully discharged or charged so as to then charge or discharge exactly 50% of the capacity of the battery cell such that a 50% state of charge is reached and / or adjusted. It should be understood that other and / or combined determination methods may be suitable.

[0027] Suitably, the cell impedance can be determined as follows: An alternating current with a fixed alternating current frequency of 1 kHz can be applied to the cell, where the alternating voltage response of the cell caused by the application is measured. "Applied" can be understood here as a synonym for "imposed". The cell impedance, in particular the value of the cell impedance, is obtained as the alternating current resistance (z = u / i) from the ratio of the measured alternating voltage u to the alternating current i.

[0028] In another design of the invention, the current limiting device is configured to be removable from the cell, in particular for repair purposes, and alternatively or additionally replaceable. This can promote the above advantages in terms of the sustainability of the battery pack.

[0029] In another design of the invention, at least one cell is configured as a multi-tab cell having at least one, in particular wound, multi-tab electrode, and alternatively or additionally configured as a tabless cell having at least one, in particular wound, tabless electrode.

[0030] Suitably, the tabless cell, in particular configured as a tabless round cell, is constructed according to US2020 / 0144676 A1. The tabless cell can be synonymously referred to as a "ring-tab cell" having at least one ring-shaped tab electrode, and alternatively or additionally as an "earless tab cell" having at least one earless tab electrode, and alternatively or additionally as an "earless cell" having at least one earless electrode, and alternatively or additionally as a "continuous tab cell" having at least one continuous tab electrode, and alternatively or additionally as a "full-tab cell" having at least one full-tab electrode.

[0031] Suitably, a battery cell generally may have two wound electrodes, which are separated from each other, in particular in a sandwich manner, by means of a separator of the respective battery cell. Here, in the case of a battery cell, in particular in the case where the battery cell is not configured as a tabless battery cell and / or not configured as a multi-tab battery cell, at least one electrode at one of its axial ends may have connection sections (tabs) that are particularly integrated and arranged separately from each other, for electrically connecting the electrode to one of the two battery cell contact sections of the battery cell in question. Here, the connection sections arranged separately from each other may form a constriction for the current flowing between the electrode in question and the battery cell contact section in question, which may result in a relatively large battery cell impedance for such a battery cell. In particular, in the state where the battery cell is charged with electrical energy, the two battery cell contact sections are electrically polarized in opposite directions. Therefore, in the state where the battery cell is charged with electrical energy, a voltage may exist at the two battery cell contact sections. The corresponding battery cell contact section may be formed by a disk-shaped and / or cap-shaped contact element of the battery cell.

[0032] Suitably, in particular different from a battery cell that is not configured as a tabless battery cell, a tabless battery cell may have at least one, in particular wound, tabless electrode, where the tabless electrode has only a single, in particular integrated, and alternatively or additionally extending around the winding axis of the tabless electrode over the entire extent of the tabless electrode, in particular extending helically, connection section at one of its axial ends, for electrically connecting the tabless electrode to the battery cell contact section in question of the two battery cell contact sections. The tabless electrode thus particularly does not have a plurality of connection sections.

[0033] Suitably, in particular different from the tabless electrode of a tabless battery cell, the multi-tab electrode of a multi-tab battery cell may have a large number of connection sections, in particular connection sections arranged directly in succession, in particular each connection section being radially bent such that two adjacent connection sections contact each other and alternatively or additionally overlap each other.

[0034] It should be understood that suitably a hybrid form of battery cell may be contemplated, where, for example, two electrodes belong to different electrode types. In some cases, it may even be contemplated that the individual electrodes belong to different electrode types, for example if the axial ends of the electrodes are configured differently.

[0035] In another design of the present invention, at least one battery cell has an axial cell height and a cell diameter measured perpendicular to the cell height. The cell diameter is from 10 mm to 30 mm. Alternatively or additionally, the cell height is from 40 mm to 78 mm.

[0036] In another design of the present invention, the current limiting device is configured to reversibly limit the current flowing between at least one battery cell and the battery device. Alternatively or additionally, the current limiting device may be configured to reversibly limit the short-circuit current flowing due to an internal and / or external short circuit of the battery pack. The reversible limitation of the current can have a beneficial effect on the sustainability of the battery pack, especially since the reversible limitation of the current does not cause a particularly permanent deactivation and / or damage of the current limiting device, so that the current limiting device retains its function after the current is limited, especially automatically, in order to remain available for subsequent current limitation.

[0037] Suitably, the current limiting device configured to reversibly limit the current has in particular at least one or exactly one electronic semiconductor switch for controllably interrupting the current, in particular a MOSFET. Alternatively or additionally, the current limiting device has in particular at least one or exactly one thermally triggerable switch, which in particular has a bimetallic element, for controllably interrupting the current. Alternatively or additionally, the current limiting device has in particular at least one or exactly one magnetically triggerable switch, which in particular has a switching mechanism and an electric coil for magnetically actuating the switching mechanism, for controllably interrupting the current. Alternatively or additionally, the current limiting device has in particular at least one or exactly one switchable resistance element for limiting the current. Alternatively or additionally, the current limiting device has in particular at least one or exactly one PTC resistance element, in particular an electrical PTC thermistor element, for limiting the current.

[0038] In another design of the present invention, the current limiting device is configured to irreversibly limit the current flowing between at least one battery cell and the battery device. Alternatively or additionally, the current limiting device may be configured to irreversibly limit the short-circuit current flowing due to an internal and / or external short circuit of the battery pack.

[0039] Suitably, the current limiting device configured to irreversibly limit the current has at least one, in particular replaceable or non-replaceable, electrical fuse conductor element for interrupting the current. Alternatively or additionally, the current limiting device may have a cutting device for irreversibly interrupting the current. The cutting device may be configured to irreversibly cut through the conductive bus bar of the battery pack that is electrically connected to at least one battery cell. The cutting device may have a sleeve in which a chemical reaction occurs starting from a certain temperature and the sleeve cuts through the bus bar by increasing the pressure (irreversibly). Alternatively or additionally, it is conceivable that the chemical reaction can be electrically triggered, in particular by current and / or by leakage current, and / or triggered depending on the pressure.

[0040] In another design of the present invention, the current limiting device is designed to automatically interrupt an electrical short circuit of the battery pack, in particular an internal and / or external electrical short circuit. In particular, the current limiting device is configured to interrupt the short circuit if there is an electrical short circuit between the electrical connection contacts of the battery pack for removably electrically connecting to a battery device. The short circuit can exist as an external short circuit outside the internal space of the housing. The short circuit can alternatively or additionally exist as an internal short circuit within the internal space of the housing of the battery pack. Alternatively or additionally, the short circuit can exist within and / or outside the cell internal space of at least one battery cell.

[0041] Suitably, the current limiting device is configured to - in particular as an alternative or addition to short circuit current limiting - limit inrush current, which flows for a duration, for example, after a battery device has been electrically connected to the battery pack and alternatively or additionally directly after the battery pack has been electrically connected to the battery device. The duration can depend on various parameters. The duration can be predetermined and alternatively or additionally depend on temperature, and alternatively or additionally depend on aging, and alternatively or additionally depend on the state of charge of the battery pack.

[0042] In another design of the present invention, the battery pack has a certain number of battery cells, in particular battery cells of the same type construction. In particular, each battery cell itself does not have an integrated current interruption device and alternatively or additionally does not have an integrated current limiting device. In other words: In particular, none of the battery cells has an integrated current interruption device and alternatively or additionally an integrated current limiting device.

[0043] Suitably, the number of battery cells can be at least or exactly 1. The number can be plural. The number of battery cells can be from 1 to 500, in particular from 3 to 200. If the number is greater than 1, the battery cells can be arranged in an electrically series-connected manner, in particular in groups, and alternatively or additionally in an electrically parallel-connected manner, in particular in groups.

[0044] In another design of the present invention, the current limiting device is configured to limit the current flowing between the battery pack and the battery device, in particular the current flowing between the battery pack and the battery device as a whole and alternatively or additionally across the battery cells. In particular, the same current limiting device is configured to limit the current flowing between the battery pack and the battery device, in particular the current flowing between the battery pack and the battery device as a whole and / or across the battery cells. Thus, the battery pack can have only a single current limiting device for all its battery cells. However, alternatively, it is conceivable that the battery pack has a plurality of current limiting devices, in particular one current limiting device for each battery cell group and / or each battery cell. The plurality of current limiting devices of the battery pack can be controlled by means of a control device of the battery pack, in particular a central control device and / or an electronic control device.

[0045] The battery system according to the present invention has a battery pack according to the present invention described above, in particular an electrical battery pack. Thus, the advantages of the battery pack according to the present invention are also transferred to the battery system according to the present invention. Additionally, the battery system includes a battery device, in particular an electrical battery device. Here, the battery device is detachably electrically connected to the replaceable electrical battery pack, in particular and detachably mechanically connected.

[0046] Suitably, the battery device has a receiving device that is essentially configured to be complementary to the battery pack, and the receiving device is configured to receive the battery pack in a replaceable manner and, in association therewith, detachably electrically connect the battery pack to the battery device.

[0047] In a design of the present invention, the electrical battery device is configured as an electrical processing device, and the electrical processing device can be operated by means of electrical energy from the battery pack. Alternatively or additionally, the battery device is configured as a charger for charging the replaceable battery pack with electrical energy to be stored.

[0048] Suitably, the battery device configured as a processing device is ground-guided and / or hand-held, in particular hand-held, and / or backpack-mounted and / or a garden processing device, a forestry processing device, a soil processing device and / or a construction processing device. The processing device can be configured to be hand-held, i.e., in particular, the processing direction of the processing device can be adjusted relative to the workpiece being processed by the user's hand operating the processing device. In particular, the processing device can be a saw (in particular a chain saw), or a pole pruner, or a hedge shear, or a hedge trimmer, or a wood trimmer or pruning shears, a cut-off grinder or a blower, or a leaf blower, or a vacuum cleaner, or a leaf sucker, or a cleaning device, or a high-pressure cleaner, or a sweeper, or a roller brush, or a sweeping brush, or a lawn mower or grass trimmer, a brush cutter or a cultivator. Additionally or alternatively, the processing device can have a processing tool and / or in particular an electric drive motor, in particular for driving the processing tool. The drive motor can be supplied with electrical energy by a battery pack, in particular for providing drive power to the processing tool.

[0049] Suitably, the battery device configured as a charger has a power connection terminal for electrical connection to an electrical energy source, for example electrical connection to a power supply network. The charger can be used to charge the accommodated battery pack with electrical energy from the energy source. The charger can have an electronic charging regulator.

[0050] It should be understood that the battery device configured as a processing device can have a power connection terminal for electrical connection to an electrical energy source, for example electrical connection to a power supply network, in order to charge the battery pack with electrical energy from the electrical energy source. In this regard, the battery device can be configured with a dual function both as a processing device and as a charger. Description of the Drawings

[0051] Further advantages and features of the present invention result from the claims and the following description of the preferred embodiments of the present invention shown based on the drawings. Here, the same reference numerals denote the same or similar or functionally identical components.

[0052] It should be understood that, without departing from the scope of the present invention, the above features and the features to be explained below can be used not only in the respectively described combinations, but also in other combinations or individually.

[0053] Figure 1 An embodiment of a battery pack according to the present invention is shown in a structural diagram,

[0054] Figure 2 Another embodiment of the battery pack according to the present invention is shown in a schematic side view,

[0055] Figure 3A battery device configured as a charger for an embodiment of a battery system according to the present invention is shown in a schematic perspective view, and

[0056] Figure 4 An embodiment of a battery system according to the present invention is shown in a schematic side view, the battery system having a battery device configured as an electrical processing device and having a battery pack according to Figure 2 the following. Detailed Embodiment

[0057] The battery pack 1, in particular an electrical battery pack, is intended for use in a battery system 30. Thus, the battery pack 1 is configured for use, for example, in the battery system 30.

[0058] The battery system 30 has the battery pack 1. Additionally, the battery system 30 has a battery device 40, in particular an electrical battery device. The battery pack 1 is configured to be removably electrically connected to the battery device 40. In the present case, the battery pack 1 is also configured to be removably mechanically connected to the battery device 40. The battery device 40 has, for example, a receiving device that is substantially configured to be complementary to the battery pack and that is configured to receive the battery pack 1 in a replaceable manner and, in connection therewith, to removably electrically connect the battery pack 1 to the battery device 40..

[0059] The battery device 40 is configured, for example, as an electrical processing device 41( Figure 4 as shown), which can supply electrical energy by means of the received battery pack 1. Alternatively or additionally, the electrical battery device 40 is configured as a charger 42( Figure 3 as shown) for charging the received battery pack 1.

[0060] Figure 4 The processing device 41 shown is an electric chain saw. The processing device 41 has, for example, a processing tool—in the present case in the form of a saw chain. Alternatively or additionally, the processing device 41 can have a drive motor, in particular an electric drive motor, which can be used to drive the processing tool. For example, the drive motor can be supplied with electrical energy by the received battery pack 1 in order to provide drive power for the processing tool.

[0061] The battery device 40 configured as a charger 42 has, for example, a power connection for electrical connection to an electrical energy source, for example in the form of a power supply network. The charger 42 is used, for example, to charge the received battery pack 1 using electrical energy from the energy source. The charger 42 can have an electronic charging regulator.

[0062] It should be understood that the battery device 40 configured as a processing device 41 can have a power connection terminal (not shown in the current case) for electrical connection to an electrical energy source in the form of, for example, a power supply network, in order to charge the accommodated battery pack 1 with electrical energy from the electrical energy source. In this regard, the battery device 40 can be configured both as a processing device 41 and as a charger 42 with a dual function.

[0063] The battery pack 1 has at least one substantially cylindrical electrical battery cell 2. The battery cell 2 is configured to store electrical energy. The battery cell 2 can have two battery cell contact sections that are oppositely polarized when the battery cell 2 is charged with electrical energy. Each battery cell contact section can be configured as a cap-shaped and / or disk-shaped. In the current case, at least one battery cell 2 is configured as a substantially cylindrical battery cell 2, i.e., as a round battery cell. The battery cell contact sections can have and / or form the axially opposite end sides of the battery cell 2.

[0064] For example, at least one battery cell 2 has an electrical battery cell impedance. Here, when an alternating current with an alternating current frequency of 1 kHz is applied, the value of the battery cell impedance is, for example, less than 10 mΩ when the state of charge of the battery cell 2 is 50% and the temperature of the battery cell 2 is between 20 °C and 25 °C. The value of the electrical battery cell impedance can be less than 5 mΩ, in particular less than or equal to 3 mΩ. The value of the electrical battery cell impedance can be greater than 0.1 mΩ, in particular greater than 0.5 mΩ, in particular greater than 1 mΩ, in particular greater than 2 mΩ.

[0065] The battery cell 2 is, for example, configured as a multi-tab battery cell 7 having at least one, in particular wound, multi-tab electrode 8. Alternatively or additionally, the battery cell 2 is, for example, configured as a tabless battery cell 9 having at least one, in particular wound, tabless electrode 10. The tabless electrode 10 can have, at one of its axial ends, only a single, in particular integrated, and / or connection section (tab) that extends around the winding axis of the tabless electrode 10 over the entire extent of the tabless electrode 10, for electrically connecting the tabless electrode 10 to the associated battery cell contact section of the two battery cell contact sections of the battery cell 2, in particular within the unit interior space 4. The tabless electrode 10 thus does not have a plurality of connection sections in the current case. Different from the tabless electrode 10 of the tabless battery cell 9, the multi-tab electrode 8 of the multi-tab battery cell 7 can have a large number of connection sections, in particular directly successively arranged connection sections that are, for example, radially bent such that two adjacent connection sections contact and / or overlap each other. It should be understood that a hybrid form of the battery cell 2 is conceivable.

[0066] For example, the battery cell 2 has an axial cell height H. In the present case, the battery cell 2 also has a cell diameter D measured perpendicular to the cell height H. Here, the cell diameter D is, for example, from 10 mm to 30 mm. Alternatively or additionally, the cell height H (as in the present case) is from 40 mm to 78 mm.

[0067] The battery pack 1 has a current limiting device 3 for limiting the current flowing between at least one battery cell 2 and the battery device 40. The current limiting device 3 can be configured to limit the short-circuit current that may flow due to an internal electrical short circuit and / or an external electrical short circuit of the battery pack 1.

[0068] The battery pack 1 has, for example, electrical connection contacts 22, in particular electrical connection contacts 22 that are exposed externally and / or in a state where the battery pack 1 is not connected to the battery device 40, and the electrical connection contacts are configured to be detachably electrically connected to the battery device 40. Here, an electrical short circuit of the battery pack 1 may exist between the connection contacts 22. An external short circuit exists, in particular, outside the housing interior space 24 surrounded by the battery pack housing 23 of the battery pack 2. An internal electrical short circuit can exist, in particular, within the cell interior space 4 between the battery cell contacts of at least one battery cell 2 and / or within the housing interior space 24. The current limiting device 3 is, for example, configured to automatically interrupt the electrical short circuit of the battery pack 1.

[0069] The current limiting device 3 of the battery pack 1 is constructed separately from at least one battery cell 2. In particular, the current limiting device 3 is constructed separately from all the battery cells 2 of the battery pack 1. The current limiting device 3 is electrically connected to at least one battery cell 2. For example, the current limiting device 3 is arranged outside the battery cell 2, in particular outside the cell interior space 4.

[0070] The current limiting device 3 is, for example, configured to reversibly limit the current flowing between at least one battery cell 2 and the battery device 40. Here, the current limiting device 3, as in the present case, can have an electronic semiconductor switch 12, for example a MOSFET 13, for controllably interrupting the current.

[0071] Alternatively or additionally, the current limiting device 3, as in the present case, can have a thermally triggerable switch 14, and the switch 14 has, in particular, a bimetallic element 15 for controllably interrupting the current.

[0072] Alternatively or additionally, the current limiting device 3, as in the present case, can have a magnetically triggerable switch 16, where the switch 16 has, in particular, a switching mechanism 17 and an electric coil 18 for magnetically actuating the switching mechanism 17. The magnetically triggerable switch 16 can be configured to controllably interrupt the current.

[0073] Alternatively or additionally, the current limiting device 3 can have a switchable resistance element 19 for limiting the current, as is the case currently.

[0074] Alternatively or additionally, the current limiting device 3 can have a PTC resistance element 20 for limiting the current, as is the case currently.

[0075] The current limiting device 3 can alternatively or additionally, as is the case currently, be configured to irreversibly limit the current flowing between at least one battery cell 2 and the battery device 40. The current limiting device 3 can here have in particular a replaceable or non-replaceable electric fuse conductor element 21 for interrupting the current. The electric fuse conductor element 21 can alternatively or additionally be integrated in the conductive busbars of the battery pack 1 and / or in the conductive battery cell connection means of the battery pack 1.

[0076] As is the case currently, the current limiting device 3 can for example be configured to limit the current flowing between at least one battery cell 2 and the battery device 40 both reversibly and irreversibly with at least partial functional redundancy. For example, the current limiting device 3 can be configured to irreversibly limit the current to a first limit value and to reversibly limit the current to a second limit value, in particular where the second limit value is smaller in magnitude than the first limit value. The battery pack 1 can have a current limiting cascade, which can be implemented in the above-described manner for example.

[0077] In the present case, the current limiting device 3 is arranged both in the electrical positive path PP of the battery pack 1 and in the electrical negative path MP. In other embodiments, the current limiting device 3 can be arranged only in the positive path PP of the electrical battery pack 1 or only in the negative path MP of the electrical battery pack 1.

[0078] Alternatively or additionally, the current limiting device 3 can be arranged in the electrical connection path VP of the battery pack 2, where the electrical connection path VP connects at least two battery cells 2 of the battery pack 1 to each other.

[0079] The connection path VP can electrically connect at least two groups of battery cells 2 to each other, in particular where the groups of battery cells are electrically connected in parallel or in series by means of the connection path VP. The battery cells 2 belonging to one group can be electrically connected in series or in parallel with each other, in particular within the group. The connection path VP extends along the conductive battery cell connection means.

[0080] One of the connection contacts 22 is present, for example, in the negative path MP, while the other of the connection contacts 22 is present in the positive path PP.

[0081] For example, the current limiting device 3 is configured to be removable from at least one battery cell 2. Alternatively or additionally, the current limiting device 3 can be configured to be replaceable, in particular modularly replaceable. This is advantageous for the maintenance of the battery pack 1 and alternatively or additionally for the repair of the battery pack 1, especially in cases where the current limiting device 3 has to be replaced.

[0082] At least one battery cell 2 of the battery pack 1 does not have a current limiting device per se. Alternatively or additionally, at least one battery cell 2 does not have a current interruption device. In other words: The battery cell 2 per se does not have any current interruption device in particular, and alternatively or additionally does not have any current limiting device.

[0083] In the present case, at least one battery cell 2 does not have a "current interruption device (CID)" present in a normal battery cell. In particular, none of the battery cells 2 of the battery pack 1 has a CID.

[0084] At least one battery cell 2 has a differential pressure valve 5. Here, the differential pressure valve 5 is configured to automatically connect the unit interior space 4 to the external environment U of the battery cell 2 in a pressure - coordinated manner when the pressure difference prevailing between the unit interior space 4 and the external environment U exceeds a predetermined limit value. This limit value can in particular be pre - determined by the structural design of the differential pressure valve 5. The differential pressure valve 5 is in particular not a CID.

[0085] For example, the pressure difference corresponds to the internal pressure p prevailing in the unit interior space 4 i and the ambient pressure p prevailing in the external environment U U The difference between them. Here, the differential pressure valve 5 can be specifically configured to connect the unit interior space 4 to the external environment U in a pressure - coordinated manner. In the present case, the differential pressure valve 5 is configured to i connect the unit interior space 4 to the external environment U in a pressure - coordinated manner when the internal pressure p U is greater than the ambient pressure p. In the present case, the differential pressure valve 5 thus serves as a pressure relief valve for releasing the pressure difference exceeding the predetermined limit value from the unit interior space 4.

[0086] For example, the differential pressure valve 5 is configured for an irreversible pressure - coordinated connection of the unit interior space 4 to the external environment U, i.e., the differential pressure valve 5 is, for example, not re - closable. Alternatively or additionally, the differential pressure valve 5 is damaged when it is opened.

[0087] The differential pressure valve 5 can have a valve body and a valve seat, which are at least partially connected by means of the rated breaking point of the differential pressure valve in the closed state, in particular connected in a material-unified and / or fluid-tight manner. To open the differential pressure valve 5, the connection between the valve body and the valve seat at the rated breaking point can be separated according to the pressure difference, thereby forming a valve opening of the differential pressure valve 5 that connects the unit internal space 4 with the environment U. In particular, the differential pressure valve 5 is integrally arranged at one of the cell contact sections of the battery cell 2.

[0088] For example, the differential pressure valve 5 is configured not to limit and alternatively or additionally not to interrupt the current, in particular the current flowing between the cell contact sections. Therefore, the differential pressure valve 5 is particularly not a CID.

[0089] In the present case, at least one battery cell 2 has a cell housing 6, which together with the differential pressure valve 5 defines the unit internal space 4. When the differential pressure valve 5 is closed, the unit internal space 4 can be separated from the external environment U in a fluid-tight manner by means of the cell housing 6 and the closed differential pressure valve 5. The cell contact section is in particular a component of the cell housing 6. In particular, the differential pressure valve 5 can open the unit internal space 4 according to the pressure difference before the cell housing 6 bursts and / or tears unexpectedly due to the pressure difference, in particular away from the cell contact section and / or away from the differential pressure valve 5.

[0090] By means of the battery pack housing 23 of the battery pack 1, for example, at least one battery cell 2 and alternatively or additionally a current limiting device 3 are accommodated. The external environment U of the battery cell 2 can exist in the housing internal space 24 of the battery pack 1 surrounded by the battery pack housing 23. In the present case, the housing internal space 24 is in fluid conduction and alternatively or additionally pressure-coordinated communication with the atmosphere A surrounding the battery pack 1.

[0091] For example, the battery pack 1 has a certain number of battery cells 2, in particular battery cells 2 of the same type. For example, the number of battery cells 2 can be from 1 to 500, in particular from 3 to 200. In particular, all the battery cells 2 are of the same type, that is to say, in particular all the battery cells 2 can have the same type. For example, the battery cells 2 are configured to be of the same type in terms of geometry and / or function.

[0092] It should be understood that the battery pack 1 can have another electrical energy storage device and / or battery that is different from at least one battery cell 2 (in particular different in terms of geometry and / or function). Such another electrical energy storage device and / or battery can be used, for example, to supply electrical energy to the electronic display of the battery pack 1 when and / or only when the charge state of at least one battery cell 2 is insufficient to operate the display, and the electronic display is used to display the battery pack state, in particular the charge state of at least one battery cell 2.

[0093] In Figure 1 the illustration of, for example, two battery cells 2 of the battery pack 1 are shown, wherein the two battery cells 2 are electrically connected in series. The battery pack 1 may have additional battery cells 2, which are electrically connected in parallel with the battery cells 2 as seen from Figure 1 . Embodiments with only battery cells 2 electrically connected in parallel are also conceivable.

[0094] In the present case, the same current limiting device 3 is configured to limit the current flowing between the battery pack 1 and the battery device 40 and alternatively or additionally to limit the current flowing due to an electrical short circuit of the battery pack 1. Here, the current limiting device 3 may be configured to limit the total and / or cross-cell current flowing between the battery pack 1 and the battery device 40. Thus, the battery cells 2 can share the current limiting device 3.

[0095] In the present case, none of the battery cells 2 has its own integrated current interruption device and / or its own integrated current limiting device.

[0096] It is conceivable that at least two battery cells 2 of the battery pack 1 are each assigned a current limiting device 3, wherein the at least two current limiting devices 3 are constructed separately from the battery cells 2. The current limiting device 3 can be controlled by means of a central electronic control device of the battery pack 1, in particular in order to limit the current of each battery cell 2 and / or across the battery cells.

Claims

1. A battery pack (1) for detachably electrically connecting to a battery device (40), wherein the battery pack (1) comprises: - at least one substantially cylindrical electrical battery cell (2) for storing electrical energy, and a current limiting device (3) which is constructed separately from at least one battery cell (2) and is electrically connected to the battery cell (2), and is used to limit the current flowing between the at least one battery cell (2) and the battery device (40); - wherein the at least one battery cell (2) has a cell interior (4) and a pressure differential valve (5), wherein the pressure differential valve (5) is designed to automatically connect the cell interior (4) to the external environment (U) in a pressure-coordinated manner if a pressure difference prevailing between the cell interior (4) and the external environment (U) of the battery cell (2) exceeds a predetermined limit value, - wherein the at least one battery cell (2) itself has no current interruption device and / or current limiting device.

2. The battery pack (1) according to claim 1, - wherein the at least one battery cell (2) has an electrical battery cell impedance, wherein when an alternating current with an alternating current frequency of 1 kHz is applied, the value of the battery cell impedance is less than 10 mΩ when the state of charge of the battery cell (2) is 50% and the temperature of the battery cell (2) is 20° C. to 25° C.

3. The battery pack (1) according to any one of the preceding claims, - wherein the current limiting device (3) is configured to be removable and / or replaceable from the battery unit (2).

4. The battery pack (1) according to any one of the preceding claims, - wherein the at least one battery cell (2) is configured as a multi-tab battery cell (7) having at least one, in particular wound, multi-tab electrode (8), and / or as a tabless battery cell (9) having at least one, in particular wound, tabless electrode (10).

5. Battery pack (1) according to any one of the preceding claims, - wherein the at least one battery cell (2) has an axial cell height (H) and a cell diameter (D) measured perpendicular to the cell height (H), - wherein the cell diameter (D) is from 10 mm to 30 mm and / or the cell height (H) is from 40 mm to 78 mm.

6. Battery pack (1) according to any one of the preceding claims, - wherein the current limiting device (3) is configured to reversibly limit the current flowing between the at least one battery cell (2) and the battery device (40), - In particular, the current limiting device (3) has: - an electronic semiconductor switch (12), in particular a MOSFET (13), for controlled interruption of the current, and / or a heat-triggerable switch (14), in particular with a bimetallic element (15), for the controlled interruption of an electric current, and / or - a magnetically triggerable switch (16), in particular having a switching mechanism (17) and an electric coil (18) for magnetically actuating the switching mechanism (17) for the controlled interruption of an electric current, and / or - a switchable resistive element (19) for limiting the current, and / or - A PTC resistor element (20) for limiting the current.

7. Battery pack (1) according to any one of the preceding claims, - wherein the current limiting device (3) is configured to irreversibly limit the current flowing between the at least one battery cell (2) and the battery device (40), In particular, the current limiting device (3) has an electrofused conductor element (21) for interrupting the current, in particular a replaceable or non-replaceable electrofused conductor element (21).

8. Battery pack (1) according to any one of the preceding claims, - wherein the current limiting device (3) is configured to automatically interrupt an electrical short circuit of the battery pack (1), in particular when an electrical short circuit exists between electrical connection contacts (22) of the battery pack (1) for detachable electrical connection to the battery device (40).

9. Battery pack (1) according to any one of the preceding claims, - wherein the battery pack (1) has a certain number of battery cells (2), in particular battery cells (2) of the same type, In particular, each battery cell (2) itself does not have an integrated current interruption device and / or an integrated current limiting device.

10. The battery pack (1) according to any one of the preceding claims, - wherein the current limiting device (3), in particular the same current limiting device (3), is constructed to limit the current flowing between the battery pack (1) and the battery device (40), in particular the current flowing between the battery pack (1) and the battery device (40) as a whole and / or across battery cells.

11. A battery system (30), comprising: - A battery (1) according to any one of the preceding claims, and A battery device (40) which is detachably connectable to the replaceable electrical battery (1) or which is detachably connectable to the replaceable electrical battery (1).

12. The battery system (30) according to claim 11, - the battery device (40) is designed as an electrical processing device (41) which can be operated with the aid of electrical energy from the battery pack (1), and / or - wherein the battery device (40) is designed as a charger (42) for charging the replaceable battery pack (1) with electrical energy to be stored.

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