High-voltage battery for a motor vehicle and motor vehicle

Abstract

High-voltage battery (2) for a motor vehicle (1) with a plurality of battery cells (3, 4) arranged in a housing (5) of the high-voltage battery (2), wherein the housing (5) has a first housing area (6) deformable by an impact force (F) and a second housing area (7) protected by the first housing area (6) from the impact force (F), wherein first battery cells (3) with a first property are arranged in the first housing area (6) and second battery cells (4) with a second property different from the first property are arranged in the second housing area (7), wherein the first housing area (6) is formed by a first sub-area of ​​an interior of the housing (5) and the second housing area (7) is formed by a second sub-area of ​​the interior of the housing (5), characterized in thatthat the high-voltage battery (2) has a destruction device (9) for destroying at least one first battery cell (3) at a point of force application (F) to the housing (5) of the high-voltage battery (2).

Description

[0001] The invention relates to a high-voltage battery for a motor vehicle, comprising a plurality of battery cells arranged in a housing of the high-voltage battery. The invention also relates to a motor vehicle.

[0002] The focus here is on high-voltage batteries or high-voltage energy storage systems for electrically powered vehicles, such as electric vehicles or hybrid vehicles. These vehicles typically have an electric drive motor or electric motor in their powertrain to propel the vehicle, as well as the high-voltage battery, which provides electrical energy to the electric drive motor. High-voltage batteries usually comprise a large number of battery cells, which can be connected to form battery modules and are arranged in a housing. In a critical event, such as a collision involving the vehicle, a force can be exerted on the housing of the high-voltage battery.

[0003] To prevent the battery cells from being destroyed by this force, it is known in the prior art, for example, to house the battery cells in non-deformable, rigid housings. From the subsequently published DE 10 2016 222 676 A1, an electrical energy storage device for a motor vehicle is known. The electrical energy storage device has several main cell modules arranged in a main housing and an emergency cell module arranged in a separate emergency housing. However, this results in an undesirably high weight for the high-voltage battery. It is also known to provide a space or buffer zone between a housing wall and the battery cells, so that an impact force on the housing wall deforms the buffer zone but not the battery cells.However, the buffer zone leads to an unfavorable ratio between the vehicle's range provided by the high-voltage battery and the installation space required for the high-voltage battery in the vehicle.

[0004] German patent DE 10 2011 089 268 A1 describes a technology for protecting a battery pack of a high-performance vehicle battery, in which an insulating film element and a bearing element are installed in a housing that surrounds the battery pack. The insulating film element is wound around and unwound from the bearing element. This technology prevents a short circuit caused by a conductive object that, for example, penetrates the high-performance battery during a vehicle accident.

[0005] DE 10 2015 216 181 B3 discloses an electrical energy storage device with several electrically coupled and interchangeable storage modules, each having a plurality of storage cells connected in series or parallel, wherein the energy storage device has storage modules of a first type having a certain energy density, wherein the energy storage device has storage modules of a second type having a higher energy density than the storage modules of the first type, and at least two storage modules of the second type fit into the spatial volume of a storage module of the first type.

[0006] The object of the present invention is to provide a particularly weight-saving and space-saving or range-optimized high-voltage battery for an electrically powered motor vehicle.

[0007] This problem is solved according to the invention by a high-voltage battery and a motor vehicle with the features according to the respective independent claims. Advantageous embodiments of the invention are the subject of the dependent claims, the description, and the figures.

[0008] A high-voltage battery according to the invention for a motor vehicle comprises a plurality of battery cells arranged in a housing of the high-voltage battery. The housing has a first housing area that is deformable by an impact force and a second housing area that is protected from the impact force by the first housing area. In the first housing area, first battery cells with a first property are arranged, and in the second housing area, second battery cells with a second property that differs from the first property are arranged.

[0009] The high-voltage battery is primarily a traction battery for electric or hybrid vehicles. It comprises a number of battery cells arranged together within the housing, specifically the high-voltage battery casing, where they may be interconnected. These battery cells can be, for example, cylindrical, prismatic, pouch, or coffee-bag-shaped. The casing itself can be cuboidal and include a wall, base, and cover.

[0010] The high-voltage battery is positioned in the vehicle in such a way that, in the event of an impact, for example, in a crash, a force path is formed through the housing. In other words, the housing is subjected to a force upon impact. The housing is then used to dissipate the impact energy. For this purpose, the housing has a first housing section, which is formed by a first section of the housing's interior. The second housing section is formed by a second section of the housing's interior. The first housing section is deformed by the impact force. The second housing section is positioned and protected by the first housing section in such a way that it is not deformed, or only minimally deformed, by the impact force.

[0011] The first battery cells with the first characteristic are located in the first housing section. Since the first housing section is deformed by the applied force, the first battery cells are also affected by this force. The first characteristic of the first battery cells is chosen, for example, such that the battery cells may be safely destroyed by the deformation of the first housing section resulting from the applied force. The first battery cells can therefore be described as sacrificial cells, which are destroyed and thus "sacrificed" during the application of force to dissipate the impact energy. Safe destruction is understood, for example, to mean destruction that does not result in a thermal event of the high-voltage battery, such as ignition of the high-voltage battery, or complete destruction of the high-voltage battery.

[0012] The second housing section contains the second battery cells, which differ in their properties from the first battery cells. Since the second housing section is not, or only minimally, deformed by the impact force, the second battery cells are not, or only minimally, affected by the force. Therefore, the second battery cells are not destroyed by the impact force and can be optimized, for example, to provide a specific characteristic of the high-voltage battery. Such a characteristic could be, for example, the vehicle's driving range provided by the high-voltage battery, its fast-charging capability, its weight and installation space, or similar factors.

[0013] In particular, the interior of the housing consists of a first and a second housing section, with each section being filled with the maximum possible number of battery cells. This eliminates the need for a buffer zone between the housing wall and the battery cells, resulting in a particularly favorable ratio between achievable range and installation space. Furthermore, the housing does not require a heavy, rigid material, as deformation of the first housing section due to the sacrificial cells within is permissible. Consequently, the high-voltage battery can be designed to be exceptionally lightweight, space-saving, and range-optimized.

[0014] It can be designed so that the first battery cells have a primary energy density, and the second battery cells have a secondary energy density that is higher than the primary energy density. The second battery cells are therefore energy-optimized. Energy density is a measure of a battery cell's energy storage capacity and thus directly influences the achievable range of the electric vehicle.

[0015] It is also possible for the first battery cells to have a high initial power density, while the second battery cells have a higher secondary power density compared to the first. The second battery cells are thus optimized for performance. In particular, they are capable of high currents and can provide high currents for short periods during the charging and discharging of the high-voltage battery. This enables, for example, fast charging of the high-voltage battery.

[0016] Battery cells with high energy density and / or power density are more prone to thermal events than those with lower energy and / or power density. By arranging the second set of high-energy and / or power-density battery cells in the second housing area and protecting them from the first set of lower-energy and / or power-density battery cells, a particularly safe high-voltage battery can be provided in the event of an impact, while simultaneously offering long range and / or fast-charging capability.

[0017] Furthermore, it can be provided that the first battery cells exhibit a first deformability as their primary property, and that the second battery cells exhibit a second deformability that is greater than the first. For example, the first battery cells can be arranged in a rigid, but heavy, battery cell housing, making them inelastic and non-deformable. The first battery cells are thus resistant to impact forces. Alternatively, it can be provided that the first battery cells have no housing or a housing that is not non-deformable, so that they are immediately destroyed by the impact. The second battery cells can, for example, be arranged in a housing that allows a certain degree of non-deformable deformation.For example, the battery cell casing of the second battery cell can be designed to be elastic. These second battery cells can, for instance, have a deformability of 10%. This varying deformability allows for the creation of a particularly weight-optimized high-voltage battery.

[0018] In a further development of the invention, the first housing area is formed adjacent to a housing wall of the housing, and the second housing area is formed adjacent to the first housing area and spaced apart from the housing wall. The second housing area is, in particular, enclosed or framed by the first housing area. The second housing area is, in particular, arranged centrally within the housing and is framed in the direction of the housing wall by the first housing area, which is adjacent to the housing wall. The housing areas are thus arranged concentrically. As a result, the second battery cells, which are arranged in the second housing area, are also framed and protected by the first battery cells arranged in the first housing area.

[0019] According to the invention, the high-voltage battery has a destruction device for destroying at least one first battery cell at a point where force is applied to the housing of the high-voltage battery. In particular, the destruction device for the first battery cells has nail-shaped elements which are arranged on the housing wall adjacent to the first housing area and are designed to destroy the associated first battery cell by puncturing it. At the point where force is applied to the housing, the destruction device destroys, in particular, only the first battery cell which is located behind the housing wall at the point of force application. For example, at least one nail-shaped element can be arranged on the inner side of the housing wall facing the first battery cell for each first battery cell.The nail-shaped element is positioned outside the corresponding first battery cell when the casing wall is undeformed and no force is applied. When the casing wall is deformed in certain areas due to the application of force, the nail-shaped element is forced into the battery cell, intentionally and deliberately destroying it. This deliberate destruction prevents a chain reaction of damage to adjacent first battery cells. This avoids a thermal event or complete failure of the high-voltage battery. The high-voltage battery is therefore designed to be particularly safe.

[0020] A motor vehicle according to the invention comprises a high-voltage battery according to the invention or an embodiment thereof. The motor vehicle is in particular designed as a passenger car in the form of an electric or hybrid vehicle.

[0021] The embodiments and advantages presented with reference to the high-voltage battery according to the invention apply accordingly to the motor vehicle according to the invention.

[0022] Further features of the invention will become apparent from the claims, the figure, and the figure description. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and / or shown in the figure alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0023] The invention will now be explained in more detail with reference to a preferred embodiment and the drawing.

[0024] The single figure shows a schematic representation of an embodiment of a motor vehicle according to the invention.

[0025] The figure shows a top view of a motor vehicle 1 according to an embodiment of the present invention. The motor vehicle 1 is designed as an electrically powered motor vehicle, for example, as an electric or hybrid vehicle. The motor vehicle 1 has a high-voltage battery 2 or a high-voltage accumulator, which provides electrical energy for an electric drive motor of the motor vehicle 1 (not shown here). The high-voltage battery 2 has a plurality of battery cells 3, 4, which are arranged in a housing 5 of the high-voltage battery 2. The battery cells 3, 4 are designed here as cylindrical cells. However, the battery cells 3, 4 can also be prismatic battery cells or pouch cells.

[0026] The housing 5 of the high-voltage battery 2 comprises a first housing area 6 and a second housing area 7. The first housing area 6 is located adjacent to a housing wall 8 of the housing 5. The second housing area 7 is located opposite the housing wall 8 and is surrounded by the first housing area 6. The first housing area 6 is deformable as a result of an impact force F acting on the housing wall 8. This force F could, for example, result from an accident or crash involving the vehicle 1. The second housing area 7 is protected by the first housing area 6 and is therefore not deformed, or only minimally deformed, as a result of the force F.

[0027] In the first housing area 6, first battery cells 3 with a first property are arranged, and in the second housing area 7, second battery cells 4 with a second property different from the first property are arranged. Since the first battery cells 3 are located in the first housing area 6, which is deformed as a result of the applied force F, they are also affected by the applied force F. The first property is selected, in particular, such that the first battery cells 3 may be destroyed to dissipate the impact energy, for example, without a thermal event or complete destruction of the entire high-voltage battery 2 occurring. The second property can, for example, be selected such that the second battery cells 4 are optimized with respect to a specific property of the high-voltage battery 2.For example, the second battery cells 4 may have a higher power density and / or a higher energy density and / or a higher deformability than the first battery cells 3.

[0028] Furthermore, the high-voltage battery 2 here has a destruction device 9, which is designed to deliberately destroy the first battery cell(s) 3 at the point of force application F in order to prevent the propagation of the destruction event to adjacent first battery cells 3. The destruction device 9 here has at least one nail-shaped element 11 on an inner surface 10 of the housing wall 8 for each first battery cell 3 adjacent to the inner surface 10, which deliberately destroys only the corresponding first battery cell 3 at the point of force application F. This deliberately destroyed first battery cell 3 can therefore not propagate the force application F to adjacent first battery cells 3. In this way, for example, a thermal event of the high-voltage battery 2 can be prevented. Reference symbol list 1 motor vehicle 2 high-voltage batteries 3 first battery cells 4 second battery cells 5 cases 6 first housing area 7 second housing area 8 Housing wall 9 Destruction device 10 Inside 11 nail-shaped element F Force application

Claims

High-voltage battery (2) for a motor vehicle (1) with a plurality of battery cells (3, 4) arranged in a housing (5) of the high-voltage battery (2), wherein the housing (5) has a first housing area (6) deformable by an impact force (F) and a second housing area (7) protected by the first housing area (6) from the impact force (F), wherein first battery cells (3) with a first property are arranged in the first housing area (6) and second battery cells (4) with a second property different from the first property are arranged in the second housing area (7), wherein the first housing area (6) is formed by a first sub-area of ​​an interior of the housing (5) and the second housing area (7) is formed by a second sub-area of ​​the interior of the housing (5), characterized in thatthat the high-voltage battery (2) has a destruction device (9) for destroying at least one first battery cell (3) at a point of force application (F) to the housing (5) of the high-voltage battery (2). High-voltage battery (2) according to claim 1, characterized in that the first battery cells (3) have a first energy density as the first property and the second battery cells (4) have a second energy density that is greater than the first energy density as the second property. High-voltage battery (2) according to claim 1 or 2, characterized in that the first battery cells (3) have a first power density as the first property and the second battery cells (4) have a second power density that is greater than the first power density as the second property. High-voltage battery (2) according to one of the preceding claims, characterized in that the first battery cells (3) have a first deformability as the first property and the second battery cells (4) have a second deformability greater than the first deformability as the second property. High-voltage battery (2) according to one of the preceding claims, characterized in that the first housing area (6) is formed adjacent to a housing wall (8) of the housing (5) and the second housing area (7) is formed adjacent to the first housing area (6) and spaced apart from the housing wall (8). High-voltage battery (2) according to one of the preceding claims, characterized in that the destruction device (9) for the first battery cells (3) has nail-shaped elements (11) which are arranged on an inner side (10) of the housing wall (8) adjacent to the first housing area (6) and are designed to destroy the associated first battery cell (3) by puncturing the associated first battery cell (3). Motor vehicle (1) with a high-voltage battery (2) according to one of the preceding claims.

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