Battery cell with heating wire, battery system and motor vehicle

Abstract

The invention relates to a battery cell (1) for a battery system (2) of a motor vehicle (3), comprising a cell housing (4), whereby a cell interior (5) having a first interior region (5a) and a second interior region (5b) is formed, an anode (6) arranged in the first interior region (5a), and a cathode (7) arranged in the second interior region (5b), a separator (8) separating the first interior space region (5a) from the second interior space region (5b) in an ion-permeable manner, the separator (8) being configured to be meltable. According to the invention, a heating wire (9) is arranged in the cell interior (5), said heating wire (9) being designed to melt the separator (8) in such a way that the ion permeability of the separator (8) can be reduced. The invention further relates to a battery system (2) for a motor vehicle (3) and to a motor vehicle (3) having an electric drive system (13).

Description

TECHNICAL FIELD

[0001] The present invention relates to a battery cell for a battery system of a motor vehicle. Furthermore, the present invention relates to a battery system for a motor vehicle and to a motor vehicle with an electric drive system. BACKGROUND

[0002] Battery cells, for example lithium-ion battery cells, are known to overheat in the event of a fault, triggering chemical side reactions within the battery cell, which sometimes lead to further overheating and ultimately to irreversible damage to the battery cell. This process is also referred to as "Thermal Runaway" (TR) or "thermal runaway".

[0003] It is therefore particularly important in the operation of battery cells to reduce the risk of thermal runaway. One known possibility for preventing or at least mitigating or delaying thermal runaway is to cool the battery cell by means of additional cooling devices. An alternative solution for cooling battery cells is known from the patent document US 2013 / 0 136 955 A1. By increasing the electrical contacts that protrude into the interior of the battery cell, heat dissipation from the interior of the battery cell to the battery housing can be improved.

[0004] The document DE 10 2014 204 245 A1 discloses a battery in which a thermal insulation layer is arranged between the battery cells. In this way, it is intended to reduce the risk of thermal runaway spreading from one battery cell to an adjacent battery cell. Furthermore, it is known to use separator layers of battery cells composed of multiple layers of different plastics. The intermediate layer is designed to melt at a critical cell temperature, for example from 120°C, and thereby suppress the ion permeability of the separator. In this way, further uncontrolled progression of the cell reaction can be prevented.

[0005] The known battery cells and battery systems have the disadvantage that additional protective measures require additional installation space. As a result, the power density of the battery is reduced and the weight of the battery is increased. Furthermore, the known battery cells and battery systems have the disadvantage that the cell reaction can usually only be mitigated and that the cell reaction spreading from one battery cell to an adjacent battery cell cannot always be reliably prevented. SUMMARY

[0006] The technical problem addressed by the present invention is therefore to overcome or at least partially overcome the above-mentioned disadvantages in battery cells. In particular, the technical problem addressed by the present invention is to provide a battery cell, a battery system and a motor vehicle that reduce the risk of thermal runaway spreading from one battery cell to an adjacent battery cell in a simple and cost-effective manner and thus have better operational safety.

[0007] The above technical problem is solved by the claims. Accordingly, the above technical problem is solved by a battery cell for a battery system of a motor vehicle having the features of independent claim 1, a battery system for a motor vehicle having the features of dependent claim 5 and a motor vehicle with an electric drive system having the features of dependent claim 10. Further features and details of the present application result from the dependent claims, the description and the drawings. Herein, the features and details described in connection with the battery cell according to the present application of course also apply in connection with the battery system according to the present application and the motor vehicle according to the present application and vice versa, so that the individual inventive aspects can be mutually referenced.

[0008] According to a first aspect of the present application, the technical problem is solved by a battery cell for a battery system of a motor vehicle. The battery cell has a cell housing, by which a cell interior is formed with a first interior region and a second interior region, the battery cell has an anode arranged in the first interior region, a cathode arranged in the second interior region, and a separator ion-permeable separating the first interior region from the second interior region, wherein the separator is configured to be meltable. According to the present application, a heating wire is arranged in the cell interior, wherein the heating wire is configured for such a melting of the separator, by which the ion permeability of the separator is purposefully reducible.

[0009] The cell housing forms the cell interior. The cell housing can have a film, a plate, a plastic, etc. The cell interior is preferably delimited by the cell housing, so that the cell chemicals arranged in the cell interior are retained in the cell interior and are prevented from exiting into the environment of the battery cell. The battery cell according to the present application can be configured as a prismatic battery cell, a round battery cell, a pouch battery cell, etc.

[0010] The cell interior is divided by the separator into the first interior region and the second interior region. An electrolyte is preferably arranged in the first interior region and the second interior region. The exchange of cell chemicals, such as electrolyte, between the first interior region and the second interior region is prevented by the separator. Furthermore, the separator is designed to be ion-permeable in order to ensure the passage of current through the battery cell. Preferably, the separator is of a multi-layered configuration, wherein at least one separator layer of the separator is designed to be meltable.

[0011] According to the present application, it can be provided that the cell interior is divided by a plurality of separators into a plurality of first interior regions and a plurality of second interior regions, which regions are preferably arranged alternately in the cell interior. Thus, the battery cell preferably has a plurality of anodes, which are respectively arranged in one of the first interior regions. Further preferably, the battery cell has a plurality of cathodes, which are respectively arranged in one of the second interior regions. The anodes, the separators and the cathodes are preferably arranged in close proximity, so that a separator is respectively arranged between the anodes and the cathodes. Preferably, each separator has a heating wire.

[0012] The meltable design of the separator is understood in the scope of the present application as that the separator, parts of the separator, separator layers, etc. are meltable such that the ion permeability of the separator is reduced, almost completely suppressed or completely suppressed. The separator or the separator layers preferably have a melting point which is lower than the critical cell temperature at which an uncontrolled thermal runaway of the cell chemistry is faced and higher than the upper non-critical operating temperature of the battery cell at which no thermal runaway occurs. A feasible melting point of the meltable separator or the meltable separator layers can be about 120°C. Thus, the separator layers can be melted either intentionally by the heating wire or by the self-heat of the battery cell in a critical operating situation in order to bring the battery cell into a non-active operating state by the ion impermeability of the separator or the separator layers caused by the melting of the separator or the separator layers as in a conventional fuse situation in which no or only a small ion flow can pass through the separator layers.

[0013] The heating wire consists of or has a metal such that a current can act through the heating wire. Further preferably, the heating wire has a relatively high electrical resistance such that it can advantageously heat up when energized. The heating wire is preferably designed in a spiral shape. The heating wire is arranged on the separator. Therein, the heating wire preferably contacts the separator.

[0014] The heating wire preferably directly contacts or contacts the meltable separator layer by a heat conducting means, such as a metal strip, etc. The heating wire is further designed to be energizable such that the heating wire heats up and heats up the separator such that the separator melts such that the ion permeability of the separator is reduced. Further preferably, the electrical connection ends of the heating wire are led out of the cell interior and are preferably arranged on the outside of the cell housing for electrical connection with the battery system such that an intentional energization of the heating wire is ensured in order to intentionally melt the separator or the separator layers.

[0015] The heating wire is preferably energizable such that the separator is melted by the heating of the heating wire in order to reduce the ion permeability of the separator by 50%, preferably by 75%, particularly preferably by 99% or 100%. Thus, an intentional energization of the heating wire can result in that the ion exchange between the first interior region and the second interior region is reducible or completely preventable. By preventing the ion exchange, a further thermal runaway can be avoided or delayed and with it a critical overheating of the battery cell.

[0016] The battery cell according to the application has the advantage over conventional battery cells that the operating safety of the battery cell is improved by simple means and in a cost-advantageous manner, and as a result also the operating safety of a battery system having a battery cell according to the application. By means of the targeted energizability of the heating wire, the battery cell can be switched into a safe state, for example, already at a cell temperature that is still below a critical temperature value (at which a thermal runaway is faced, for example). In other words, a fuse blowing can be achieved at a lower cell temperature. Excessive heating of the battery cell can thus be avoided or delayed, and in this way also the excessive heating of adjacent battery cells can be avoided or delayed. In an early targeted intervention by targeted melting of the separator of one or more battery cells, for example, damage to other battery cells of the battery system can be avoided, so that the capacity loss of the battery system in the event of a thermal runaway can be reduced.

[0017] According to a preferred refinement of the application, provision can be made in the battery cell for the heating wire to be partially or completely embedded in the separator. Preferably, the heating wire is partially or completely embedded in a separator layer that is configured to be meltable. Preferably, the heating wire is arranged in the separator in a plurality of planes, for example two planes. It is preferred here that the heating wires of a first heating wire plane are arranged between two heating wires of a second heating wire plane, and vice versa, in order to ensure as reliable and uniform a melting of the separator layer as possible. This has the advantage that the operating safety of the battery cell is further improved by simple means and in a cost-advantageous manner.

[0018] According to the application, the heating wire preferably has aluminum and / or copper or is made of aluminum or copper. Such metals have a particularly advantageous thermal conductivity. Furthermore, aluminum and copper have a particularly advantageous resistance to cell chemistries, so that the risk of corrosion of the heating wire, in particular of the part of the heating wire that is not embedded in the separator, is advantageously reduced. This has the advantage that the operating safety of the battery cell is further improved by simple means and in a cost-advantageous manner.

[0019] Further preferably, the heating wires are arranged on the separator in a heating structure, wherein the heating wire density of the heating structure is configured to be different on the separator. The heating structure can for example be designed in one or more planes parallel to the separator. By the different heating wire density of the heating wires of the heating structure it can be achieved that regions of the separator are heated and thus melted with different intensity. Preferably, the different design is configured in a stepped manner, such that the heating wire density increases, for example continuously, progressively, in steps, etc., from one side of the separator to the opposite side. In this way, for example by a first current intensity it can be achieved that only a first partial region of the separator becomes ion-impermeable due to melting, while a second partial region of the separator is configured to remain ion-permeable. In this way, the energy supply of the battery cell continues to be ensured. In the event of a continued increase in the battery cell temperature, the heating wires are energized by a second current intensity which is higher than the first current intensity, such that a larger partial region of the separator than the first partial region becomes ion-impermeable. By this targeted energization of the heating wires a targeted change in the ion permeability of the separator can be caused. This has the advantage that the operating safety of the battery cell is further improved by simple means and in a cost-advantageous manner.

[0020] According to a second aspect of the application, the technical problem is solved by a battery system for a motor vehicle. The battery system has a system housing and a plurality of battery cells arranged in the system housing. According to the application, at least one battery cell is configured as a battery cell according to the application. Further preferably, at least half of the battery cells are configured as battery cells according to the application. Particularly preferably, all battery cells of the battery system according to the application are configured as battery cells according to the application.

[0021] The system housing can be configured as a system housing of a conventional battery system. The system housing can for example consist of or at least have metal, plastic, fiber-reinforced plastic, etc. The battery cells are arranged in the system housing, for example as a battery cell stack, etc. The battery cell stack is preferably pressed against the system housing, for example by means of a pressure device arranged in the system housing. The battery system preferably has a battery management system for operating the battery system. The battery management system is preferably configured for monitoring the battery cells, for example for monitoring the battery cell current, the battery cell temperature, etc. The battery management system can for example be configured for monitoring and / or controlling the charging and / or discharging of the battery cells.

[0022] The battery cell according to the application has respectively an electrically conductive body configured as an anode and a cathode. In addition, the battery cell according to the application has a connection end for a heating wire. By means of the connection end, the heating wire can be loaded with an electric current in order to thereby melt the separator or the separator layer in a targeted manner and in this way to reduce or completely suppress the ion permeability of the separator in a targeted manner.

[0023] In the battery system according to the application, all the advantages described for the battery cell according to the first aspect of the application are obtained. The battery system according to the application thus has the advantage over conventional battery systems that the operating safety of the battery cell, and thus also of the battery system having the battery cell according to the application, is improved by simple means and in a cost-advantageous manner. By means of the targeted energizability of the heating wire, the battery cell can be switched into the safe state, for example, already at a cell temperature that is still below the critical temperature value (at which a thermal runaway is faced, for example). In other words, the fusing can be achieved at a lower cell temperature. Overheating of the battery cell, and thus also of the adjacent battery cells, can thus be avoided or delayed in this way. In the early targeted intervention by targeted fusing of the separator of one or more battery cells, for example, damage to other battery cells of the battery system can be avoided or delayed, so that the capacity loss of the battery system in the event of a thermal runaway can be reduced.

[0024] In a particularly preferred design of the application, it can be provided in the battery system that a thermal switch is arranged on at least one second battery cell of the plurality of battery cells, wherein the thermal switch is designed to energize the heating wire of the first battery cell to fuse the separator of the first battery cell upon reaching a threshold temperature of the second battery cell. The second battery cell can likewise be configured as a battery cell according to the application. It is likewise preferred that a thermal switch is also arranged in the first battery cell, wherein the thermal switch is designed to energize the heating wire to fuse the separator of the second battery cell upon reaching a threshold temperature of the first battery cell, and further preferably to energize the heating wire to fuse the separator of a further directly adjacent battery cell. Thus, for example, upon detection of a critical cell temperature of an intermediate battery cell by the thermal switch of the intermediate battery cell, the heating wires of two directly adjacent battery cells can be directly energized in order to better avoid the critical cell temperature being reached by these adjacent battery cells, and the overheating spreading to further battery cells of the battery system. By means of the thermal switch, it can be ensured that, when a critical cell temperature is reached by an adjacent battery cell, the battery cell is switched into an inactive state in order to avoid a chain reaction between the battery cells, which would lead to a thermal runaway of the respective battery cell. In this way, the damage to the battery system can be limited to a smaller number of battery cells. This has the advantage that the operating safety of the battery system is further improved by simple means and in a cost-advantageous manner.

[0025] Preferably, the heating wire of the at least one first battery cell is electrically coupled with at least one third battery cell of the plurality of battery cells, such that the heating wire is energizable by the at least one third battery cell in order to melt the separator of the at least one first battery cell. The third battery cell can be any battery cell of the battery system. Thus, the third battery cell can for example correspond to the second battery cell and / or be arranged directly at an end of the stack of battery cells. According to the present application, it can be provided that the third battery cell is configured as a battery cell according to the present application. Also according to the present application, it can be provided that the third battery cell is arranged directly adjacent to the first battery cell. Also according to the present application, it can be provided that the third battery cell is arranged outside of the battery system and is configured as a lead-acid battery. By providing the electric current by the third battery cell, it is ensured that sufficient electric energy is provided in order to bring the first battery cell into the inactive state, even in case of a failure of the battery system. This has the advantage that the operational safety of the battery system is further improved by simple means and in a cost-advantageous way.

[0026] According to a preferred embodiment of the present application, in the battery system, it can be provided that the heating wire is electrically coupled with a battery management system of the battery system, such that the heating wire is energizable by the battery management system in order to melt the separator. The battery system preferably has one or more temperature sensors for determining a cell temperature of one or more battery cells. Preferably, the battery system has at least one temperature sensor for each battery cell in order to determine the respective cell temperature. The battery management system is preferably coupled with the one or more temperature sensors, such that the heating wire of one or more battery cells of the battery system can be energized by the battery management system in a targeted manner depending on the respective cell temperature. For example, if it is determined by the battery management system that a cell temperature of a battery cell reaches a critical temperature limit, the battery management system can energize the heating wire of the respectively adjacent battery cell in a targeted manner and thereby bring it into the inactive state. In this way, overheating of these battery cells and thereby excessive heating of further adjacent battery cells can be prevented in a targeted manner. This has the advantage that the operational safety of the battery system is further improved by simple means and in a cost-advantageous way.

[0027] It is particularly preferred that the battery management system is configured to detect a thermal runaway of one of the battery cells and then to selectively energize the heating wires of adjacent battery cells in order to switch these battery cells into an inactive state and thereby to avoid an overheating of these battery cells and of further adjacent battery cells. The thermal runaway can be detected by the battery management system, for example, by determining a voltage drop or a temperature change of the relevant battery cell which is characteristic for this. This can also be determined by means of a cell pressure or a cell pressure change. Furthermore, the thermal runaway can also be determined by detecting cell gas which flows out (for example by means of a temperature sensor which is arranged outside the battery cell and inside the system housing, for example in the region of a predetermined breaking point of the cell housing of the battery cell). This has the advantage that the operating safety of the battery system is further improved by simple means and in a cost-advantageous manner.

[0028] According to a third aspect of the application, the technical problem is solved by a motor vehicle. The motor vehicle has an electric drive system with an electric motor for driving the motor vehicle. According to the application, the electric drive system has a battery system according to the application for supplying the electric motor with electrical energy. The battery system of the electric drive system is designed as a traction battery.

[0029] In the motor vehicle according to the application, all the advantages already described for the battery cell according to the first aspect of the application and for the battery system according to the second aspect of the application are obtained. The motor vehicle according to the application thus has the advantage over conventional motor vehicles that the operating safety of the battery cell, and thus also of the battery system having the battery cell according to the application, is improved by simple means and in a cost-advantageous manner. By means of the selective energizability of the heating wires, the battery cell can be switched into a safe state, for example, when the cell temperature is still below a critical temperature value at which a thermal runaway is imminent. In other words, a fuse blowing is achieved at a lower cell temperature. An excessive heating of the battery cell, and thus also of adjacent battery cells, can thereby be avoided. In the case of an early, targeted intervention by means of the targeted melting of the separator of one or more battery cells, for example, damage to other battery cells of the battery system can be avoided, so that the capacity loss of the battery system in the event of a thermal runaway can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] The battery cell according to the application, the battery system according to the application and the motor vehicle according to the application are explained further below with the aid of the drawings. The respective illustration is:

[0031] Figure 1 The battery cell according to the preferred embodiment of the application is shown in a sectional view;

[0032] Figure 2 The separator according to the first preferred embodiment of the application is shown in a sectional view;

[0033] Figure 3 a separator according to a second preferred embodiment of the application is shown in a top view; Figure 2 a separator according to a second preferred embodiment of the application is shown in a top view;

[0034] Figure 4 a separator according to a second preferred embodiment of the application is shown in a top view;

[0035] Figure 5 a battery cell according to a further preferred embodiment of the application is shown in a sectional view;

[0036] Figure 6 a preferred embodiment of a motor vehicle according to the application is shown in a side view.

[0037] In the drawings Figures 1 to 6 Elements having the same function and the same mode of action are provided with the same reference signs in the various figures. DETAILED DESCRIPTION

[0038] Figure 1 A battery cell 1 according to a preferred embodiment of the application is shown schematically in a sectional view. The battery cell 1 has a cell housing 4, from which a cell interior 5 is formed and outwardly delimited. A separator 8 is arranged centrally in the cell interior 5, which divides the cell interior 5 into a first interior region 5a and a second interior region 5b. The first interior region 5a and the second interior region 5b are configured to be of identical size.

[0039] An anode 6 of the battery cell 1 is arranged in the first interior region 5a, wherein a portion of the anode 6 is led out of the cell housing 4 for electrical connection of the battery cell 1. A cathode 7 of the battery cell 1 is arranged in the second interior region 5b, wherein a portion of the cathode 7 is led out of the cell housing 4 for electrical connection of the battery cell 1. The separator 8 is designed to be fluid-tight and ion-permeable, in order to enable ion flow between the anode 6 and the cathode 7 and to inhibit further exchange of cell chemicals, such as electrolyte, between the first interior region 5a and the second interior region 5b.

[0040] A heating wire 9 is arranged inside the separator 8. For electrical connection, the heating wire 9 is led out of the separator 8 and out of the cell housing 4. The heating wire 9 is designed to be electrically conductive, so that the heating wire 9 can thereby heat and melt the separator 8 by heating of the heating wire 9, with which the ion permeability of the separator 8 can be reduced or completely prevented. The battery cell 1 can thus be brought into an inactive operating state by targeted electrical melting of the heating wire 9 only at a lower cell temperature, so that the risk of overheating of adjacent battery cells 1 is reduced.

[0041] Furthermore, a thermal switch 11 is arranged on the cell housing 4, which is designed to energize an electrical circuit for energizing the heating wires 9 of one or more directly adjacent and preferably further battery cells 1 in order to initiate a fuse in these battery cells 1 and to thereby reduce the overheating of these battery cells 1 and of further adjacent battery cells 1 in a targeted manner when a predefined critical cell temperature of the battery cell 1 is exceeded.

[0042] Figure 2 A separator 8 according to a preferred first embodiment of the application is schematically shown in a sectional view. Figure 3 A separator 8 according to a preferred first embodiment of the application is schematically shown in a top view. Figure 2 A separator 8 according to a preferred first embodiment of the application is schematically shown in a top view. The heating wires 9 in the separator 8 are arranged in a grid-shaped heating structure on one plane. The heating structure of this plane can be formed by one heating wire 9 or even two or more heating wires 9.

[0043] Figure 4 A separator 8 according to a preferred second embodiment of the application is schematically shown in a top view. The separator 8 is configured in multiple layers. The heating wires 9 in the separator 8 are arranged in a grid-shaped heating structure on two parallel planes, wherein the planes are configured in different separator layers of the separator 8. Furthermore, the heating structures of the two planes are arranged offset to each other, such that sections of the heating wires 9 of one plane are arranged between two sections of the heating wires 9 of the respective other plane, respectively. The heating structures of the two planes can be formed by one heating wire 9 or even two or more heating wires 9.

[0044] Figure 5 A battery cell 1 according to a further preferred embodiment of the application is schematically shown in a sectional view. The battery cell 1 has a cell housing 4, from which a cell interior 5 is formed and outwardly delimited. A plurality of separators 8 is arranged in the cell interior 5 parallel to each other and spaced apart from each other, whereby the cell interior 5 is divided into a plurality of first interior regions 5a and a plurality of second interior regions 5b, which are arranged alternately adjacent to each other, respectively. The first interior regions 5a and the second interior regions 5b are configured to be of the same size.

[0045] An anode 6 of the battery cell 1 is arranged in the first interior regions 5a, respectively, and a cathode 7 of the battery cell 1 is arranged in the second interior regions 5b, respectively. The anodes 6 and the cathodes 7 are preferably surrounded by an electrolyte. Connection terminals for connecting the anodes 6 and the cathodes 7 are not shown.

[0046] Figure 6 A preferred embodiment of a motor vehicle 3 according to the application is schematically shown in a side view. The motor vehicle 3 has an electric drive system 13 with an electric motor 14 for driving the motor vehicle 3. For providing electric energy to the electric motor 14, the drive system 13 has a battery system 2 according to the application.

[0047] The battery system 2 has a system housing 10, in which a plurality of battery cells 1 according to the application are arranged in a horizontally oriented stack of battery cells. For controlling and monitoring the battery cells 1, the battery system 2 has a battery management system 12, which is likewise arranged inside the system housing 10.

[0048] List of reference signs

[0049] 1 battery cell

[0050] 2 battery system

[0051] 3 motor vehicle

[0052] 4 cell housing

[0053] 5 cell interior

[0054] 5a first interior region

[0055] 5b second interior region

[0056] 6 anode

[0057] 7 cathode

[0058] 8 separator

[0059] 9 heating wire

[0060] 10 system housing

[0061] 11 thermal switch

[0062] 12 battery management system

[0063] 13 electric drive system

[0064] 14 electric motor

Claims

1. A battery cell (1) for a battery system (2) for a motor vehicle (3), the battery cell comprising a cell housing (4), a cell interior (5) with a first interior region (5a) and a second interior region (5b) being formed by the cell housing, the battery cell comprising an anode (6) arranged in the first interior region (5a), a cathode (7) arranged in the second interior region (5b), and a separator (8) separating the first interior region (5a) from the second interior region (5b) in an ion-permeable manner, wherein: The separator (8) is constructed to be fusible, It is characterized by: A heating wire (9) is arranged in the cell interior (5), wherein the heating wire (9) is designed to melt the separator (8), thereby reducing the ion permeability of the separator (8).

2. The battery cell (1) according to claim 1, It is characterized by: The heating wire (9) is partially or completely embedded in the separator (8).

3. The battery cell (1) according to claim 1 or 2, It is characterized by: The heating wire (9) comprises aluminum and / or copper or is made of aluminum or copper.

4. The battery cell (1) according to claim 1, It is characterized by: The heating wires (9) are arranged on the separator (8) in accordance with a heating structure, wherein the heating wire density of the heating structure on the separator (8) is configured to be different.

5. A battery system (2) for a motor vehicle (3), comprising a system housing (10) and a plurality of battery cells (1) arranged in the system housing (10), It is characterized by: At least one first battery cell ( 1 ) of the plurality of battery cells ( 1 ) is designed as a battery cell ( 1 ) according to one of the preceding claims.

6. The battery system (2) according to claim 5, It is characterized by: A thermal switch (11) is arranged on at least one second battery cell (1) of a plurality of battery cells (1), wherein the thermal switch (11) is designed to energize a heating wire (9) of a first battery cell (1) when a threshold temperature of the second battery cell (1) is reached, so as to melt a separator (8) of the first battery cell (1).

7. Battery system (2) according to claim 5 or 6, It is characterized by: A heating wire (9) of at least one first battery cell (1) is electrically coupled to at least one third battery cell (1) of the plurality of battery cells (1), such that the heating wire (9) can be energized by the at least one third battery cell (1) to melt a separator (8) of the at least one first battery cell (1).

8. The battery system (2) according to claim 5, It is characterized by: The heating wire (9) is electrically coupled to a battery management system (12) of the battery system (2), so that the heating wire (9) can be energized by the battery management system (12) to melt the separator (8).

9. The battery system (2) according to claim 8, It is characterized by: The battery management system (12) is designed to detect thermal runaway of one of the battery cells (1) and subsequently energize the heating wires (9) of adjacent battery cells (1) in a targeted manner.

10. A motor vehicle (3) having an electric drive system (13) with an electric motor (14) for driving the motor vehicle (3), It is characterized by: The electric drive system (13) comprises a battery system according to one of claims 5 to 9 for supplying electrical energy to an electric motor (14).

Images