Battery arrangement for a motor vehicle, motor vehicle and method for switching off a battery unit

Abstract

The invention relates to a battery arrangement (10) for a motor vehicle (26) comprising a battery group (12) comprising several battery units (14; 14a, 14b, 14c, 14d) each with at least one battery cell (16), a detection device (36) for detecting an event, and a control device (44) for switching off at least one of the battery units (14; 14a, 14b, 14c, 14d) depending on the detected event.The detection device (36) is designed to detect an external mechanical force (40) on the battery group (12) as the event and to determine a spatial area of ​​the mechanical force (40), wherein the control device (44) is designed to select at least one first of the several battery units (14; 14a, 14b, 14c, 14d) from the battery group (12) depending on the determined spatial area (32; 32a, 32b, 32c, 32d) and to switch off the at least one selected first battery unit (14; 14a, 14b, 14c, 14d).

Description

[0001] The invention relates to a battery arrangement for a motor vehicle, wherein the battery arrangement comprises a battery group comprising a plurality of battery units, each with at least one battery cell, a detection device for detecting an event, and a control device for deactivating at least one of the battery units depending on the detected event. Furthermore, the invention also relates to a motor vehicle and a method for deactivating at least one of a plurality of battery units in a battery group of a motor vehicle.

[0002] DE 10 2018 222 450 A1 describes a high-voltage battery arrangement for a motor vehicle, comprising at least a first and a second battery segment, and a detection device for detecting a fire in the at least one first and / or second battery segment. Furthermore, the high-voltage battery arrangement comprises a coupling device designed, at least in the event of a detected fire in the at least one first or the at least one second battery segment, to electrically decouple the battery segment affected by the fire from the group of the at least one first and the at least one second battery segment, so that energy is supplied to a drive unit only by the at least one other battery segment not affected by the fire.

[0003] Disconnection of the affected battery segment can therefore only occur after the affected battery segment has already caught fire. However, it would be desirable to prevent such a fire from occurring in the first place, or at least to reduce the risk of fire.

[0004] DE 10 2019 110 349 A1 describes a method for determining mechanical defects in a battery system, wherein the battery system comprises a module with multiple battery cells and a sensor system that measures the impedance of at least one battery cell. The measured value is compared with a reference value in order to determine, based on the comparison, a change in the impedance characteristic of a mechanical defect. If a deviation of the measured value from the reference value is detected, a warning signal can be issued and / or a notification can be sent to a workshop. The impedance can be used to detect damage to a frame that spans a battery module with multiple battery cells.

[0005] The object of the present invention is to provide a battery arrangement, a motor vehicle and a method which, on the one hand, allow the earliest and most differentiated detection possible of an event which may lead to a thermal runaway of a battery cell of the battery arrangement, in particular before a fire has started, and which, on the other hand, also allow the initiation of the most differentiated measure possible to reduce the risk of fire.

[0006] This object is achieved by a battery arrangement, a motor vehicle, and a method having the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0007] A battery arrangement according to the invention for a motor vehicle comprises a battery group comprising a plurality of battery units, each having at least one battery cell. Furthermore, the battery arrangement comprises a detection device for detecting an event and a control device for deactivating at least one of the battery units depending on the detected event. The detection device is designed to detect, as the event, a mechanical force applied to the battery group external to the vehicle and to determine a spatial area of ​​the mechanical force applied. The control device is designed to select at least a first of the plurality of battery units from the battery group depending on the determined spatial area and to deactivate the at least one selected first battery unit.

[0008] The invention is based on the finding that battery units of a battery, for example a high-voltage battery, are often arranged in the underbody area of ​​a motor vehicle, which represents a location very exposed to external mechanical forces. The impact of external objects on the vehicle from below, for example a stone chip or similar, can lead to damage to one or more of the battery units if the impact is sufficiently intense. Furthermore, the invention is based on the finding that precisely such external mechanical force application can be the cause of thermal runaway of a battery cell in such a battery unit. Therefore, on the one hand, it is particularly advantageous to detect such external mechanical force application in order to be able to initiate measures at an early stage to prevent a battery fire or at least reduce the risk of fire.What is particularly advantageous, however, is that not only can the mechanical application of force be detected as such, but also the area in which this mechanical application of force is taking place or has taken place can be determined. This in turn enables particularly differentiated measures to be initiated, namely the targeted shutdown of the battery unit affected by the mechanical application of force. By shutting down such a battery unit, a particularly effective countermeasure can be provided to prevent fires or to reduce the fire risk. Continuing to operate a damaged battery unit could further aggravate the damage to the battery unit, even if it is only operated until the motor vehicle has reached a workshop, for example. By shutting it down, a particularly effective immediate measure can be provided.The fact that not all battery units necessarily have to be switched off, but rather others that are not affected by the mechanical force, for example, can continue to operate, advantageously also enables the motor vehicle to continue driving or the battery arrangement to continue operating. The motor vehicle can, for example, easily reach the nearest workshop or at least a safe parking location. By switching off at least one battery unit, the battery arrangement as a whole is therefore not immediately rendered inoperable, and the motor vehicle, in which the battery arrangement is preferably used, can continue driving, at least temporarily.The invention thus advantageously enables a particularly differentiated, in particular area-specific, detection of an event, namely a mechanical force external to the vehicle which could result in a thermal runaway of a battery cell, as well as the particularly differentiated initiation of a countermeasure in order to reduce the risk of fire, and furthermore enables the continued operation of the battery arrangement at least temporarily.

[0009] The battery group can be designed as a battery with multiple battery cells. The battery cells can be lithium-ion cells, for example. Furthermore, the battery cells can be grouped into individual groups that provide the respective battery units. The battery cells of different battery units are preferably not spatially mixed. The battery group can, for example, be subdivided into multiple spatial areas, with each spatially connected spatial area containing only battery cells of the same battery unit. Each spatial area can therefore be assigned to a battery unit. A battery unit can, for example, be a battery module. A battery unit can also comprise multiple battery modules. However, grouping the battery cells comprised in the battery group or forming battery modules is not absolutely necessary.The battery cells can be designed, for example, as round cells, pouch cells or prismatic battery cells.

[0010] The detection device and the control device can be part of the same structural unit or they can be implemented as separate structural units. Furthermore, they can be configured to communicate with each other, so that information about the detection of the event and the specific area can be transmitted from the detection device to the control device.

[0011] In principle, there are multiple ways in which the detection device can be designed to detect a mechanical force external to the vehicle. Examples include force sensors, pressure sensors, motion sensors, optical sensors (e.g., cameras), or similar. To localize the mechanical force, i.e., to determine the spatial area of ​​the mechanical force application, several spatially distributed sensors can be provided, for example, and / or sensors that each monitor a specific spatial area.

[0012] Furthermore, several spatial areas can be defined in which a mechanical force external to the vehicle can be detected independently of one another. Exactly one of the battery units can be assigned to each of these spatial areas. If the mechanical force external to the vehicle is detected in a specific spatial area, the control device can use this assignment, which can be stored, for example, in a memory of the control device, to determine the assigned first battery unit and deactivate it accordingly.

[0013] Disconnecting the first battery unit preferably means electrically decoupling or separating the first battery unit from an electrical circuit of the multiple battery units and / or bypassing the battery unit. The first battery unit can therefore be deactivated, for example, by electrically bypassing the first battery unit. Circuit devices for bypassing battery units are known from the prior art. Disconnecting or bypassing can be implemented, for example, by means of one or more switches, e.g., at least one electronically controllable switch.

[0014] The battery group is generally designed as a whole to supply energy to a drive unit of the motor vehicle. Deactivation of the first battery unit is preferably configured such that the energy supply to the drive unit can then only be provided by the non-deactivated battery units included in the battery group.

[0015] According to a further advantageous embodiment of the invention, the battery arrangement comprises an underrun protection device arranged below the battery group with respect to a first direction and at a distance from the battery units of a battery group with respect to the first direction. The detection device is designed to detect contact between the underrun protection device and at least one of the battery units to detect the mechanical force application and to determine the area of ​​the detected contact to determine the spatial area of ​​the mechanical force application. The underrun protection device can advantageously protect the battery group from below.The distance between the battery units and the underrun protection can advantageously provide a buffer zone that can prevent minor force applications of the underrun protection in the direction of the battery group, which could lead to deformation of the underrun protection and / or global or local movement of the underrun protection in the direction of the battery group, from directly causing contact with the battery units. In the case of larger force applications, which, for example, lead to local contact between the underrun protection and at least one of the battery units, this contact can advantageously be detected, and the affected battery unit can be selected as the first battery unit, which can then be deactivated.For example, if contact occurs with several of the battery units, all of these affected battery units can be selected as the respective first battery unit and switched off accordingly.

[0016] Contact between the underrun protection and one of the battery units can be easily detected, e.g., using a corresponding contact sensor. Furthermore, such contact can also be easily localized. The battery unit that comes into contact with the underrun protection can thus be easily selected as the first battery unit and deactivated. This ensures that a particular battery unit is only deactivated if it actually made contact with the underrun protection. This reliably prevents unnecessary deactivation of other, unaffected battery units.

[0017] The underrun protection can, for example, be designed as a plate-like cover which extends perpendicular to the first direction over at least the entire surface of the battery group. The underrun protection can also be fastened to the underside of the battery group. The battery group can, for example, have a frame and / or a battery housing with such a frame, wherein this battery housing can optionally be subdivided, for example by partitions or dividers, into individual receiving areas for accommodating a respective battery unit. The underrun protection can, for example, be arranged on the frame and / or on these partitions or dividers. A connection between the underrun protection and the battery housing or the frame and / or the dividers can be designed elastically via spring-loaded connecting elements which allow movement of the underrun protection in the direction of the battery units.This allows external forces acting on the underrun protection to be absorbed and dampened particularly efficiently. Should contact occur between the underrun protection and one or more of the battery units, this can advantageously be detected by the detection device, and the battery units affected by the contact, i.e. those contacted by the underrun protection, can be deactivated.

[0018] The spatial area of ​​the mechanical force application can therefore advantageously be determined by determining which of the battery units was at least temporarily in contact with the underrun protection.

[0019] Therefore, it represents a further very advantageous embodiment of the invention if the underrun protection has a plurality of electrically conductive layer segments separated from one another, wherein each layer segment is assigned to exactly one battery unit, wherein a respective battery unit of the plurality of battery units and the layer segment respectively assigned to the battery unit are opposite one another with respect to the first direction, and wherein the detection device is designed to detect a contact between at least one of the layer segments and the assigned battery unit as a function of a measured electrical variable, in particular a change in the electrical variable.

[0020] This represents a particularly simple and advantageous option for detecting contact between the underrun protection and one of the battery units. The electrically conductive, mutually separated layer segments can lie essentially in one plane. They are spatially separated from one another in such a way that there is no electrically conductive connection between the individual layer segments. This advantageously makes it possible to electrically detect electrical contact between such a layer segment and the associated battery unit, independently for each of the layer segments. Depending on which of the layer segments such contact was detected for, the associated battery unit can be easily selected and switched off. Each layer segment preferably defines exactly one spatial area.If contact of a specific layer segment with the associated battery unit is detected, the spatial area defined by the layer segment represents the specific spatial area of ​​the mechanical force application.

[0021] It should also be noted that it is not necessary to detect which of the battery units a layer segment comes into contact with. For example, it is sufficient to detect that a layer segment is in contact with the battery group. The assignment of the contacting layer segment to the associated battery unit to be switched off can be based on a simple spatial assignment. In other words, the battery unit located above the contacting layer segment with respect to a first direction can then simply be switched off.

[0022] Such layer segments can also be implemented in a particularly simple manner. For example, they can be implemented as metal plates or metal flakes, metal foils, metal adhesive tapes, or electrically conductive coatings or lacquers, for example, as metal coatings.

[0023] The measured electrical quantity can be, for example, an electrical voltage and / or an electrical current and / or an electrical resistance. It is particularly advantageous if a change in the electrical quantity is used to detect the contact. The electrical quantity in question can be continuously monitored, for example, using the detection device, and in the event of a predetermined change, for example, greater than a predetermined limit, the contact can be considered detected. Such monitoring can be implemented separately for each of the layer segments.

[0024] According to a further advantageous embodiment of the invention, the underrun protection comprises an underrun protection plate which is arranged below the battery group with respect to the first direction, wherein the layer segments are arranged between the underrun protection plate and the battery group, in particular on a side of the underrun protection plate facing the battery group. The layer segments can also be flat. This allows possible contacts between the underrun protection and a corresponding battery unit to be detected particularly reliably. In particular, the underrun protection plate can be largely or essentially almost completely covered by the layer segments, although this does not necessarily have to be the case. In order to ensure electrical insulation between the layer segments, they can be spaced apart from one another.The electrically non-conductive area resulting from such a distance can, for example, be smaller than the total area of ​​the layer segments.

[0025] Because the layer segments are arranged between the underrun protection plate and the battery group, on the one hand, it is easily possible for the layer segments to contact the battery units in the event of an external force being applied, and this contact can be easily detected, and on the other hand, the layer segments themselves are particularly well protected against environmental influences at this position.

[0026] The underrun protection plate can, for example, have a first side assigned to the battery pack. The layer segments can be arranged on this first side. The first side of the underrun protection plate can be electrically insulating. Optionally, the entire underrun protection or the entire underrun protection plate can also be electrically insulating. The layer segments can, as already mentioned, be arranged on the first side of the underrun protection plate in the form of a film and / or a metallic adhesive tape and / or an electrically conductive coating.

[0027] According to a further advantageous embodiment of the invention, the detection device is designed to determine for which of the multiple layer segments contact with the associated battery unit was detected, and to identify the region of the detected contact as the layer segment for which contact with the associated battery unit was detected. In this way, contact with the respective battery unit can be easily localized. Consequently, only the layer segment(s) that were or are in contact with their associated battery unit need to be determined.

[0028] According to a further advantageous embodiment of the invention, the detection device comprises a measuring unit and a plurality of detection lines, wherein the measuring unit is electrically connected to each of the layer segments via one of the detection lines. This allows for particularly simple electrical detection of contact between a respective layer segment and the associated battery unit. The multiple detection lines associated with different layer segments are also electrically insulated from one another. This advantageously allows for separate detection of whether or not each individual layer segment is in contact with the associated battery unit.

[0029] According to a further advantageous embodiment of the invention, each of the battery units has an underside facing the underrun protection, which is electrically conductive and which is at a specific electrical first potential, in particular a ground potential, wherein preferably all of the undersides are at the same electrical first potential.

[0030] The undersides of the battery units can be designed as separate components or they can also be provided by a single component. For example, the battery housing described above can have a housing base on which the battery cells of the respective battery units are arranged. The housing base can be divided into individual sub-areas, with each sub-area being assigned to a battery unit and representing the underside of the assigned battery unit. The housing base can also be designed, for example, as a cooling base, i.e., provided by a cooling plate in which cooling channels through which a cooling medium can flow are integrated.The housing base or such a cooling plate can be made of a metallic material or, at least on the side facing the underrun protection, be electrically conductive, for example, with a metallic coating or a metallic foil. However, it is preferred if the housing base itself or the respective undersides of the battery units are made of a metallic material. The battery housing can also have a separate housing base for each of the battery units. The individual housing bases can be in electrical contact with one another. The housing bases can also be arranged in contact with one another, thus forming a large base plate.

[0031] Housing parts, such as the one or more housing bases, are at a ground potential if they are made of an electrically conductive material. The individual bottom sides of the battery units therefore do not need to be electrically separated from one another. This simplifies the structure of the battery group. In this case, only the layer segments can be electrically separated from one another. This allows contact between a respective layer segment and the associated battery unit to be clearly detected, and the layer segment that has contact with the associated battery unit to be clearly identified.

[0032] However, it would also be conceivable for the layer segments to be electrically connected to one another and for the respective electrically conductive undersides of the battery units to be electrically insulated from one another. This would also make it possible to clearly detect which of the battery units is or was in contact with the underrun protection. If the undersides of the battery units are electrically insulated from one another, the above-mentioned detection lines can also be contacted or electrically connected to the respective undersides of the battery units instead of to the respective layer segments in order to detect contact between a respective battery unit and the underrun protection or the layer segment. However, this variant is less preferred because it leads to a more complex design of the battery group, in particular the housing base.In contrast, electrically separated layer segments, for example by metallic foil strips or coating strips, can be very easily implemented on the underrun protection plate.

[0033] According to a further advantageous embodiment of the invention, a respective layer segment is at a second electrical potential different from the first potential, wherein the measuring device is designed to monitor a respective potential difference between the respective second potential and the first potential for each of the layer segments and to detect a change in the potential difference as the electrical quantity.

[0034] The potentials mentioned here in the context of the invention are electrical potentials.

[0035] The first potential can be greater or smaller than the second electrical potential. A potential difference is generally also referred to as voltage. The measuring device can therefore be designed to monitor the voltage between a respective layer segment and the undersides of the battery units. If one of these voltages changes, the corresponding contact between the respective layer segment and the associated battery unit can be considered detected. The associated battery unit can be deactivated accordingly. In principle, it is conceivable for each of the layer segments to be at a different second potential.

[0036] However, it is particularly simple if the layer segments are each at the same second potential, at least as long as they are not in contact with the associated battery unit. The measuring device can also be designed to apply this second potential to each of the layer segments. For this purpose, the measuring device can be designed to apply a corresponding voltage to the respective layer segments relative to ground potential, for example, via the detection lines described above. The voltage does not have to be particularly high and can, for example, be just a few volts.

[0037] In the event of contact between one of the layer segments and the associated battery unit, particularly the electrically conductive underside, a certain potential equalization occurs between the two different potentials, which can advantageously be detected by the measuring device. In particular, a corresponding voltage drop in the magnitude of the voltage occurs between this affected segment and the underside of the associated battery unit. This voltage drop can be detected particularly reliably and easily.

[0038] The layer segment assigned to the detection line over which the measuring unit detected this voltage drop can then be considered as the specific spatial area in which contact with the associated battery unit took place and, accordingly, as the area of ​​mechanical force application.

[0039] Furthermore, the invention also relates to a motor vehicle with a battery arrangement according to the invention or one of its embodiments.

[0040] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0041] Furthermore, the invention also relates to a method for deactivating at least one of a plurality of battery units of a battery group of a motor vehicle, wherein a detection device detects an event and a control device deactivates at least one of the battery units depending on the detected result. The detection device detects, as the result, a mechanical force applied to the battery group external to the vehicle and determines a spatial area of ​​the mechanical force applied. The control device selects at least a first of the plurality of battery units from the battery group depending on the determined spatial area and deactivates the at least one selected first battery unit.

[0042] The invention also includes further developments of the method according to the invention that have features already described in connection with the further developments of the battery arrangement according to the invention. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0043] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0044] The control device and / or the detection device and / or a device comprising the control device and / or the detection device can have a data processing apparatus or a processor device that is configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). In particular, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit) or an NPU (Neural Processing Unit) can be used as the microprocessor. Furthermore, the processor device can have program code that is configured to carry out the embodiment of the method according to the invention when executed by the processor device.The program code can be stored in a data memory of the processor device. The processor device can be based, for example, on at least one circuit board and / or on at least one SoC (System on Chip).

[0045] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0046] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 is a schematic plan view of a battery arrangement according to an embodiment of the invention; Fig. 2 a schematic representation of the battery arrangement from Fig. 1 in a cross-section according to an embodiment of the invention; Fig. 3 a schematic representation of a motor vehicle with a battery arrangement according to an embodiment of the invention.

[0047] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0048] In the figures, the same reference symbols designate elements with the same function.

[0049] The coordinate systems shown are preferably Cartesian coordinate systems. The z-direction shown preferably corresponds to the direction previously referred to as the first direction.

[0050] Fig. 1 shows a schematic representation of a battery arrangement 10 in a plan view according to an embodiment of the invention. The battery arrangement comprises a battery group 12, which comprises a plurality of battery units 14. Each battery unit 14 comprises at least one battery cell 16. In this example, the battery units 14 are designed as battery modules. The battery group 12 also comprises a battery housing 18, which comprises a frame 20 surrounding the battery units and partition walls 22, by means of which the individual receiving areas in which the respective battery units 14 are received are spatially separated from one another. The partition walls 22 are merely optional. In addition, the battery housing 18 can also have a housing base 24 (cf. Fig. 2). The battery housing 18 can be made of a metallic material. However, the battery housing 18 can also be made partially or entirely of a plastic. Parts of the battery housing 18 can be made of a metallic material, and parts of it can be made of a plastic material.

[0051] The individual battery units 14 provide separately switchable segments of the battery group 12. In other words, not all battery units 14 need to be used simultaneously to operate a motor vehicle 26 (see Fig. 3), but only some of these battery units 14 may contribute to the operation, for example if one or more of the battery units 14 have been switched off, as will be explained in more detail below.

[0052] For better differentiation, the individual battery units 14 are additionally designated 14a, 14b, 14c, 14d.

[0053] Fig. 2 shows a schematic cross-sectional view of the battery arrangement 10 from Fig. 1. The battery housing 18, and accordingly also the housing base 24, are at a first potential P1, which is defined here as a ground potential. Each of the battery units 14 has an associated underside 24a, 24b, 24c, 24d, wherein these undersides 24a, 24b, 24c, 24d are simultaneously provided as a region of the housing base 24 of the battery housing 18. Respective undersides 24a, 24b, 24c, 24d are electrically conductive and are also at the common first potential P1. The undersides 24a, 24b, 24c, 24d are therefore not electrically insulated from one another.

[0054] With respect to the illustrated z-direction, an underrun protection device 28 is arranged below the battery group 12. The underrun protection device 28 comprises an underrun protection plate 30. The underrun protection plate 30 has a first side 30 facing the battery group 12. In addition, the underrun protection device 28 has a distance d from each of the battery units 14. This distance can be substantially the same for all battery units 14. The underrun protection device 28 can also be attached to the battery housing 18 and / or to other body components of the motor vehicle 26 (see Fig. 3). The underrun protection 28 and in particular the underrun protection plate 30 extends in the xy plane over at least the entire surface of the battery group 12. The underrun protection 28 can thus advantageously protect the battery group 12 from below.

[0055] Advantageously, the underrun protection 28 now comprises at least one electrically conductive layer. In the present example, the underrun protection 28 comprises a plurality of such electrically conductive layers 32, which can also be referred to as layer segments 32. For better differentiation, the individual layer segments 32 are also referred to here as 32a, 32b, 32c, 32d. Each layer segment 32 is assigned to the battery unit 14 directly opposite it with respect to the z-direction. The individual layer segments 32 can be made of or comprise an electrically conductive material. For example, the layer segments can be formed as respective foils. For example, as a copper foil or as an aluminum foil. They can also be designed as an electrically conductive adhesive tape, for example, as a self-adhesive copper foil or as an aluminum adhesive tape.The individual segments 32 can also have a multi-layer structure, wherein at least the uppermost layer with respect to the illustrated z-direction, i.e., the layer facing the associated battery unit 14, represents a metal layer. The remaining layers do not necessarily have to be electrically conductive, but can also be electrically insulating. The layer segments 32 can also be provided in the form of an electrically conductive coating. Such a coating can be applied to the first side 30a, for example, by spraying it onto the first side 30a, or by printing or painting it on, or by another application method.

[0056] The individual layer segments 32 are designed to be electrically insulated from one another. This can be easily achieved by at least the first side 30a of the underrun protection plate 30 being designed to be electrically insulating, for example, made of a plastic material, and by the layer segments 32 also being spaced apart by a distance D. The distances D between the individual layer segments 32, for example in the x-direction shown here, can be the same or different. Furthermore, the layer segments 32 extend in the y-direction over a length that is at least as long as the length of the associated battery unit 14 in the y-direction.

[0057] The battery group can be segmented into individual battery units 14 not only in the y-direction, but alternatively or additionally also in the y-direction. The respectively assigned layer segments 32 can then also be correspondingly segmented alternatively or additionally in the y-direction. The dimensions of a respective layer segment 32 in the x-direction can essentially correspond to the dimensions of the assigned battery units 14 or can also be smaller. In principle, they can also be larger, provided that the electrical insulation of the individual layer segments 32 from one another is ensured, for example, over the aforementioned distance D. Such electrical insulation can also be implemented differently, for example, by means of insulation elements, insulation films, or in the form of electrically insulating components between the layer segments 32.

[0058] Each of the layer segments 32 is at a second potential P2. This second potential P2 can, for example, be measured by a measuring unit 34 (see Fig. 3) a detection device 36 (see Fig. 3). This second potential P2 can be the same for each of the layer segments 32 or can be selected differently. The second potential P2 is different from the first potential P1. In a normal state, in which there is no contact between the layer segments 32 and the battery units 14, a voltage defined by the potential difference between the second and first potential P2, P1 is present at the respective layer segments 32. If local contact occurs between such a layer segment 32 and the associated battery unit 14, this electrically conductive connection results in potential equalization and, accordingly, a measurable voltage drop at the corresponding layer segment 32. This can be measured, for example, via a respective measuring line 38a, 38b, 38c, 38d assigned to the respective layer segment 32, which were previously also referred to as a detection line.

[0059] In the present example, the situation is represented by a vehicle-external mechanical force application 40 by a bollard 42. The force application 40 acts at least partially in the z-direction and causes, for example, a local deformation or local movement of the underrun protection 28 in the direction of the battery group 12. In this example, it results in the third layer segment 32 being brought into contact, at least temporarily, with the underside 24c of the associated battery unit 14c. This contact can be detected, in particular via the described voltage drop at the associated detection line 38c. A control device 44, which is also part of the battery arrangement 10, can then deactivate the associated battery unit 14c. The deactivation is designated 46 here.The remaining battery units 14a, 14b, 14d, for which no contact with the associated layer segment 32a, 32b, 32d was detected, continue to operate accordingly. This continued operation is designated 48 in the present case. The shutdown 46 can occur, for example, by decoupling the relevant battery unit 14c or its cells 16 from the interconnection of the battery units 14, or by bridging them. The switched-off battery unit 14c then no longer contributes to the operation of the motor vehicle 26, in particular no longer to the drive. A supply voltage for the battery group 12 can be provided, for example, via a supply connection assigned to the battery group 12, which is not shown here, however. The battery voltage of the battery group 12 can be tapped from this connection.If one of the battery units 14 is switched off, in this example the third battery unit 14c, it no longer contributes to the voltage or current provided at the supply connection.

[0060] Fig.3 shows a schematic representation of a motor vehicle 26 with a battery arrangement 10 according to an exemplary embodiment of the invention. The battery arrangement 10 can be designed as previously described. The detection of contact between such a layer segment 32 and the associated battery unit 14 will now be explained in more detail. The present illustration can also be interpreted as a cross-section, for example, perpendicular to the x-direction shown. Thus, only one battery unit 14 is shown here, for example, the first battery unit 14a and the associated layer segment 32, 32a. To detect contact 50 between the layer segment 32a and the associated battery unit 14a, this contact 50 being illustrated by way of example by the circle shown, the battery arrangement 10 now comprises a detection device 36. This detection device can comprise the aforementioned measuring device 34.Each layer segment 32 is connected to the measuring device 34 via a specially assigned detection line. The detection line assigned to the first layer segment 32a is designated 38a in the present case. The detection device 36 or the measuring device 34 can have a corresponding input 34a, which can be designed, for example, as an analog input 34a. In addition, the measuring device 34 also comprises a voltage output 34b via which a corresponding voltage can be provided at the detection line 38a in order to apply the layer segment 32a to the second potential P2. The voltage output 34b can be connected to the detection line 38a via an electrical component 52. The component 52 is, for example, an electrical resistor. The component 52 can alternatively or additionally also be an electrical capacitor and / or an electrical coil or have one or more of these.The detection line 38a can also directly electrically connect the input 34a to the layer segment 32a.

[0061] The detection device 36 can be embodied as an electronic control unit (ECU). The aforementioned control device 44 can also be part of the detection device 36 or be designed as a separate structural unit. For each layer segment 32, the detection device 36 or the measuring device 34 can have a corresponding input 34a and a corresponding voltage output 34b. The individual inputs 34a are then electrically connected to the respective associated detection lines 38a, 38b, 38c, 38d. The outputs 34b are also connected to the corresponding detection lines 38a, 38b, 38c, 38d via respective electrical components 52, as illustrated here for the first detection line 38a.

[0062] In the present example, four battery segments, i.e., battery units 14 and associated layer segments 32, are provided. More or fewer can also be provided, for example, only two or three, or even more, for example, five or six, or more than ten. In principle, there are no limits to the number of layer segments. However, a number of fewer than ten is advantageous, as this allows the battery arrangement 10 to be implemented particularly simply and efficiently.

[0063] If contact 50 occurs between the contact surface, i.e., layer segment 32a, and battery housing 18, the second potential P2 is pulled to ground potential P1. This can be detected by detection device 36. Depending on which layer segment 32 this contact was detected for, the associated battery unit 14 can be shut down.

[0064] Overall, the examples demonstrate how the invention can provide a segmented shutdown of battery cells. This enables segment-by-segment shutdown of battery cells depending on an external mechanical load, also referred to as a mechanical force applied external to the motor vehicle. This provides an additional safety advantage. The battery arrangement can comprise individual battery segments or cells, previously also referred to as battery units, as well as a sensor system that enables segment-by-segment shutdown of the individual battery segments. The sensor system can comprise the aforementioned detection device, the detection lines, and the electrically conductive layer segments.The individual battery segments can be disconnected from the power supply if external damage occurs; more precisely, they are decoupled from the battery system so that they no longer contribute to the power supply. The assessment and classification of locally occurring external damage is carried out in particular by the sensor system, which is capable of tracking and detecting external mechanical damage. In particular, the sensor system can be designed as a contact switch. Each battery segment can be assigned its own contact switch. The underrun protection comprises an underrun protection plate, which can also be referred to as a protective plate. The protective plate is arranged below the battery box, which contains the housing and the cells enclosed by the battery units. The protective plate is designed with segmented contact surfaces, or these segmented contact surfaces are arranged on the protective plate.

[0065] There are various ways to detect deformations in the underrun protection and resulting damage to the battery. Previous solutions involve additional effort, which must be accepted by the project team. A simplified solution with significantly lower costs is described within the scope of the invention. The battery arrangement comprises a detection system for detecting contact between the underrun protection and the battery housing. The detection system comprises electrically conductive surfaces on the upper side of the underrun protection, as well as an electrically conductive connection or supply line to the vehicle's electronic architecture, which was also referred to as a detection device. The electrically conductive surfaces on the upper side of the underrun protection were previously also referred to as layer segments.The contact surface is or are connected to the vehicle's electronic architecture via a respective supply line. The contact surface or contact surfaces are integrated and electrically insulated from the vehicle ground. Deformation of the underrun protection leads to contact between the contact surface and the battery casing, which is made of metal, at least for sufficiently large deformations. Contact with the vehicle ground pulls the potential of the respective layer segment to ground. The ECU's analog-in input detects a voltage jump from the voltage originally applied to the segment to ground and interprets this as contact. This can be implemented analogously for several separate and conductive contact surfaces on the upper side of the underrun protection. This enables localization of the contact. The electrically conductive surface can be designed as a foil, conductive paint, or coating.The electrically conductive surface can be subsequently applied to the underrun protection and, if applicable, to any fire protection inserts located on it, for example, by adhesive bonding. The electrically conductive surface can be integrated directly into the manufacturing process of the FRP (fiber-reinforced plastic) underrun protection, particularly on its upper surface. The electrical surface can be implemented as a thin metal foil or plastic foil with a conductive coating. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2018 222 450 A1

[0002] DE 10 2019 110 349 A1

[0004]

Claims

[1] Battery assembly (10) for a motor vehicle (26), the battery assembly (10) comprising - a battery group (12) comprising a plurality of battery units (14; 14a, 14b, 14c, 14d) each having at least one battery cell (16), - a detection device (36) for detecting an event, - a control device (44) for switching off at least one of the battery units (14; 14a, 14b, 14c, 14d) depending on the detected event, characterized by , that - the detection device (36) is designed to detect, as the event, a vehicle-external mechanical force application (40) to the battery group (12), and - to determine a spatial area of ​​the mechanical force application (40), and - wherein the control device (44) is designed to select at least a first of the plurality of battery units (14; 14a, 14b, 14c, 14d) from the battery group (12) depending on the determined spatial area (32; 32a, 32b, 32c, 32d) and to switch off the at least one selected first battery unit (14; 14a, 14b, 14c, 14d). [2] Battery arrangement (10) according to claim 1, characterized by , that - the battery arrangement (10) comprises an underrun protection device (18) which is arranged below the battery group (12) with respect to a first direction (z) and at a distance (d) from the battery units (14; 14a, 14b, 14c, 14d) of the battery group (12) with respect to the first direction (z), - wherein the detection device (36) is designed to detect a contact (50) between the underrun protection (18) and at least one of the battery units (14; 14a, 14b, 14c, 14d) for detecting the mechanical force application (40), and - to determine the spatial area (32; 32a, 32b, 32c, 32d) of the mechanical force application (40) by determining the area (32; 32a, 32b, 32c, 32d) of the detected contact (50). [3] Battery arrangement (10) according to one of the preceding claims, characterized by , that - the underrun protection (18) has a plurality of electrically conductive, mutually separated layer segments (32; 32a, 32b, 32c, 32d), - wherein each layer segment (32; 32a, 32b, 32c, 32d) is assigned to exactly one battery unit (14; 14a, 14b, 14c, 14d), - wherein a respective battery unit (14; 14a, 14b, 14c, 14d) of the plurality of battery units (14; 14a, 14b, 14c, 14d) and the layer segment (32; 32a, 32b, 32c, 32d) respectively assigned to the battery unit (14; 14a, 14b, 14c, 14d) are opposite one another with respect to the first direction (z), - wherein the detection device (36) is designed to detect a contact (50) between at least one of the layer segments (32; 32a, 32b, 32c, 32d) and the associated battery unit (14; 14a, 14b, 14c, 14d) as a function of a measured electrical variable, in particular a change in the electrical variable. [4] Battery arrangement (10) according to one of the preceding claims, characterized by in that the underrun protection (18) comprises an underrun protection plate (30) which is arranged below the battery group (12) with respect to the first direction (z), wherein the layer segments (32; 32a, 32b, 32c, 32d) are arranged between the underrun protection plate (30) and the battery group (12), in particular are arranged on a side (30a) of the underrun protection plate (30) facing the battery group (12). [5] Battery arrangement (10) according to one of the preceding claims, characterized byin that the detection device (36) is designed to determine for which of the plurality of layer segments (32; 32a, 32b, 32c, 32d) the contact (50) to the associated battery unit (14; 14a, 14b, 14c, 14d) was detected and to determine the area (32; 32a, 32b, 32c, 32d) of the detected contact (50) as the layer segment (32; 32a, 32b, 32c, 32d) for which the contact (50) to the associated battery unit (14; 14a, 14b, 14c, 14d) was detected. [6] Battery arrangement (10) according to one of the preceding claims, characterized by in that the detection device (36) comprises a measuring unit (34) and a plurality of detection lines (38a, 38b, 38c, 38d), wherein the measuring unit (34) is electrically connected to each of the layer segments (32; 32a, 32b, 32c, 32d) via one of the detection lines (38a, 38b, 38c, 38d). [7] Battery arrangement (10) according to one of the preceding claims, characterized byin that each of the battery units (14; 14a, 14b, 14c, 14d) has an underside (24a, 24b, 24c, 24d) facing the underrun protection (18), which is electrically conductive and which is at a specific electrical first potential (P1), in particular a ground potential (P1), wherein preferably all of the undersides (24a, 24b, 24c, 24d) are at the same electrical first potential (P1). [8] Battery arrangement (10) according to one of the preceding claims, characterized by that a respective layer segment (32; 32a, 32b, 32c, 32d) lies at a second electrical potential (P2) different from the first potential (P1), wherein the measuring device (34) is designed to monitor a respective potential difference between the respective second potential (P2) and the first potential (P1) for each of the layer segments (32; 32a, 32b, 32c, 32d) and to detect a change in the potential difference as the electrical quantity. [9] Motor vehicle (26) with a battery arrangement (10) according to one of the preceding claims. [10] Method for switching off at least one of several battery units (14; 14a, 14b, 14c, 14d) of a battery group (12) of a motor vehicle (26), - wherein a detection device (36) detects an event, and - a control device (44) which switches off at least one of the battery units (14; 14a, 14b, 14c, 14d) depending on the detected event characterized by , that - the detection device (36) detects as the event a vehicle-external mechanical force application (40) to the battery group (12), and - to determine a spatial area (32; 32a, 32b, 32c, 32d) of the mechanical force application (40), and - wherein the control device (44) selects at least a first of the plurality of battery units (14; 14a, 14b, 14c, 14d) from the battery group (12) depending on the determined spatial area (32; 32a, 32b, 32c, 32d) and switches off the at least one selected first battery unit (14; 14a, 14b, 14c, 14d).

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