High-voltage energy store for a motor vehicle

Abstract

The invention relates to a high-voltage energy store (10) for a motor vehicle (50), having a plurality of battery cells (13), which are arranged in an interior space (12) enclosed by a housing (11), the battery cells (13) being fixed in the interior space (12) by means of a medium (16), wherein the medium (16) has a separating device (15).

Description

Technical Field

[0001] This invention relates to a high-voltage energy storage device for a motor vehicle, comprising a plurality of battery cells disposed within an internal space surrounded by a housing, the battery cells being secured within the internal space by means of a medium having a separation device. Furthermore, this invention also relates to a motor vehicle having at least one such high-voltage energy storage device. Background Technology

[0002] High-voltage energy storage devices (also known as drive batteries or drive accumulators) are known for providing electrical energy to the electric drive systems of motor vehicles. Such high-voltage energy storage devices typically have an arrangement of multiple battery cells interconnected in parallel and series via contact devices and housed within a casing. The battery cells, along with the contact devices, are usually encapsulated or cast in an adhesive structural foam to ensure mechanical stability and provide thermal and / or electrical insulation.

[0003] In the event of an accident, the high-voltage energy storage device or its casing may deform, and this deformation may extend into the interior of the casing and therefore into the area of ​​the battery cells and their contact devices. Such deformation may damage the conductive contact system and / or detach from the battery cells, which could cause undesirable and hazardous short circuits and / or thermal events. Summary of the Invention

[0004] Against this backdrop, the objective of this invention is to improve a high-voltage energy storage device for motor vehicles. In particular, the high-voltage energy storage device should be improved in such a way that greater safety can be achieved in the event of deformation caused by an accident.

[0005] This task is accomplished by a high-voltage energy storage device for a motor vehicle having the features of claim 1 and a motor vehicle having the features of claim 10. The dependent claims relate to advantageous extensions of the invention.

[0006] According to a first aspect, a high-voltage energy storage device for motor vehicles is proposed, having a plurality of battery cells disposed in an internal space surrounded by a housing, the battery cells being fixed in the internal space by means of a medium, wherein the medium has a separation device configured to at least partially separate the medium when a force is applied to the housing.

[0007] This allows for the separation of the composite material consisting of the dielectric and battery cells—particularly in a targeted or locally predetermined manner—to avoid or even prevent undesirable damage to the battery cells and / or other components potentially disposed within the internal space of the casing. The separation device can provide a predetermined fracture point within the dielectric, ensuring that force-based deformation occurs primarily within this predetermined area of ​​the dielectric or high-voltage energy storage device. This, for example, avoids short circuits and / or thermal events caused by deformation, thereby improving the safety of the high-voltage energy storage device in the event of deformation due to an accident.

[0008] High-voltage energy storage devices, particularly energy storage devices or drive batteries for motor vehicles, have multiple battery cells. The housing of this high-voltage energy storage device defines an internal space in which the battery cells are housed or disposed. Cylindrical battery cells are used in particular, and these cells can be provided in a stacked arrangement. The battery cells, for example, have a circular cross-section and a longitudinal axis perpendicular to that cross-section. In the installation state in a motor vehicle, the high-voltage energy storage device and / or battery cells are particularly arranged such that the longitudinal axis of the battery cells is parallel to the vertical direction of the vehicle. The internal space can have a substantially cuboid geometry defined by the walls of the housing. The housing thus has, for example, a housing cover configured as a basin and / or a housing groove configured as a basin, which together enclose the internal space. The housing, housing cover, and / or housing groove can have sidewalls, wherein two of these sidewalls can be arranged opposite each other in the lateral direction of the vehicle in the installation state in a motor vehicle.

[0009] To protect the individual battery cells from mechanical shock and / or vibration, especially under normal operating conditions, a medium, particularly adhesive or bonding, is filled in the gaps between the battery cells and / or within the casing. This medium can be, for example, a two-component material and / or, for example, containing silicone, silicone foam, epoxy resin, epoxy foam, and / or polyurethane foam. Thus, the battery cells are fixed together by means of the medium, particularly between themselves and relative to the casing, forming a composite that is particularly non-removable without damage. Consequently, when a load (e.g., force or impact) is applied to the casing, this load can be transferred to the composite consisting of the medium and the battery cells, potentially causing deformation and / or damage or destruction of the composite.

[0010] The present invention is based on the concept of absorbing deformation energy into a specific region of the internal space or medium and thereby separating the medium at a predetermined location to avoid damage to the battery cells. To this end, a separation device is proposed to be provided in the medium. This separation device is configured to separate the medium when the housing deforms under load / force, thereby forming, for example, cracks / fractures in the medium. "Separation or breakage of the medium" in the sense of this disclosure is particularly understood as the failure of the cohesiveness / internal adhesion and / or adhesiveness of the medium (especially adhesion to the separation device). Such failure can be initiated, for example, by the formation and / or propagation of at least one crack and can be accompanied by loss of medium stability and / or cohesive or adhesive fracture, especially after reaching a critical crack length and / or after the separation device detaches from the medium. Thus, the deformation energy caused by force (especially in the predetermined region) is absorbed to avoid or prevent greater damage to the entire high-voltage energy storage system.

[0011] In one embodiment, the separation device is configured to separate the medium spaced apart from the cell contact devices of the battery cells. The cell contact devices may be configured to enable electrical parallel and / or series connections of the battery cells within a cell complex. For this purpose, the cell contact device has at least one connecting device configured to provide electrical connections between the battery cells. For example, the cell contact device may be constructed as a stamped or laser-cut cell contact sheet and disposed on the end face or electrode of a battery cell in a high-voltage energy storage device to connect the positive and / or negative contacts of the battery cells.

[0012] Because the medium can be separated from the current-carrying cell contact device in operation, or in other words, broken or detached at a location separated from the cell contact device, the detachment of the cell contact device or its components from the battery cell can be avoided, which could lead to thermal events and / or short circuits in the battery cell. This improves the safety of high-voltage energy storage devices under deformation conditions.

[0013] In one embodiment, the separation device is spaced apart from the cell contact device of the battery cell. The separation device may be configured to detach or separate the medium from the separation device upon the application of deformation energy. This separation device may be constructed, for example, as a thin plate, sheet, or film, spaced apart from the cell contact device in the vertical or longitudinal direction of the battery cell and embedded in or surrounded by the medium. The separation device can thus form a plane, which can serve as a predetermined fracture point or predetermined fracture surface. This allows for targeted, particularly spatially confined and / or predetermined separation of the medium, thereby improving the protection of the cell contact device and / or the battery cell.

[0014] In one embodiment, the separation device is disposed between the battery cell and the housing cover. The housing cover may, for example, have four sidewalls connected by a common cover plate and, for example, be configured to form the housing together with the bottom of the housing, which is constructed as a tray. Since in a typical operating arrangement of a high-voltage energy storage device, the cell contact device is located in the vertically upper region of the high-voltage energy storage device, by disposing the separation device between the housing cover and the battery cell, the separation device can be positioned vertically above the area where the cell contact device of the battery cell is located, thereby enabling separation spaced apart from the cell contact device.

[0015] In one embodiment, the separation device is disposed in a plane parallel to the cell contact device of the battery cell. This separation device may extend between the sidewalls of the housing or the sidewalls of the housing cover and / or may have an area larger or smaller than the cell contact device. This parallel arrangement of the separation device allows failure to occur within a plane (i.e., at a uniform distance from the cell contact device in area), thus avoiding damage to the cell contact device and / or battery cell due to undesirable crack and / or fracture formation in directions outside the plane.

[0016] In one embodiment, the separating device is configured as a planar shape. This separating device is configured to be substantially flat and / or level and / or have a relatively small height compared to its length and width dimensions, particularly in the range of 0.1 mm to 1.5 mm. With this planar configuration, a predetermined fracture surface can be predetermined by means of the separating device, so that crack and / or fracture formation can be predetermined in a desired manner.

[0017] In one embodiment, the separation device has a first adhesion coefficient on a first surface and a second adhesion coefficient on a second surface, and these two adhesion coefficients are different from each other. Here, the adhesion coefficient specifically refers to the adhesive strength / mechanical bond between the medium and the surface of the separation device, and can, for example, characterize the resistance to tensile and / or shear loads. This adhesion coefficient can be based, for example, on surface properties (e.g., roughness) or on surface treatment using a primer or varnish to improve the connection between the medium and the separation device. Thus, the failure / fracture tendency at the interface between surfaces with a smaller adhesion coefficient can be greater than that at the other surface, thereby enabling targeted localization of the failure initiation point.

[0018] In one embodiment, the adhesion coefficient of the separation device on the surface facing the cell contact device is greater than the adhesion coefficient of the separation device on the surface away from the cell contact device. Therefore, failure of the medium can be initiated at the surface spaced apart from the cell contact device, and the separation device can remain in the medium or at a location spaced apart from the cell contact device, thereby providing improved protection for the cell contact device and / or the battery cell.

[0019] In one embodiment, the separating device has a structure on at least one of its surfaces configured for a form-locking connection with the medium. This provides a mechanical connection between the separating device and the medium, designed to fail only when a predetermined deformation load is exceeded. Such a structure can be provided, for example, through at least one undercut and / or other geometrical variation provided in the surface, and can act on or influence the adhesion coefficient of the respective surface.

[0020] According to another aspect, a motor vehicle is proposed, which has at least one high-voltage energy storage device as described herein. It goes without saying that the effects and advantages described herein can be utilized by such a motor vehicle. Attached Figure Description

[0021] Other advantages and applications of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. The drawings are as follows: Figure 1 A schematic diagram of an embodiment of a motor vehicle according to the present invention is shown, the motor vehicle having a high-voltage energy storage device according to the present invention; Figure 2a , 2b A schematic diagram of one embodiment of a high-voltage energy storage device for motor vehicles according to the present invention is shown. Detailed Implementation

[0022] Figure 1 A motor vehicle 50 according to the present invention is shown, which has a high-voltage energy storage device 10 according to an embodiment of the present disclosure.

[0023] A high-voltage energy storage device 10 is disposed in the bottom region of the vehicle 50 and is configured to provide energy to the drive unit of the vehicle 50, which is not further shown or described herein. The high-voltage energy storage device 10 has a housing 11 that surrounds an internal space 12. A plurality of battery cells 13 are disposed in the internal space 12 formed by the housing 11, and these battery cells are electrically interconnected or connected to each other by means of cell contact devices 14 disposed on their end faces.

[0024] Vertically, a separation device 15 is disposed above and spaced apart from the battery cell 13 and the cell contact device 14. The internal space 12 is filled with a medium 16, which surrounds the components disposed therein, namely the battery cell 13, the cell contact device 14, and the separation device 15, or fills the gaps formed therebetween and connects the components into a composite or fixes the components. The medium 16 may be configured to be adhesive and / or cohesive to improve the mechanical stability of the high-voltage energy storage device 10.

[0025] The separation device 15 is configured to at least partially separate the medium 16, or in other words, cause the medium 16 to fail structurally, when a force is applied to the housing 11. For this purpose, the separation device 15 is constructed in a planar shape, for example, in the form of a layer, film, or layup, and has a first adhesion coefficient H1 on a first surface 17 and a second adhesion coefficient H2 on a second surface 18. The adhesion coefficient H2 on the surface 18 facing the monomer contact device 14 is greater than the adhesion coefficient H1 on the surface 17 facing away from the monomer contact device 14.

[0026] Thus, the deformation of the housing 11 caused by force can be achieved in the internal space 12 by the separation medium 16, so as to avoid or prevent damage to the individual contact device 14 and / or battery cell 13 of the high voltage energy storage device 10.

[0027] exist Figure 2a and 2b Partial views of another embodiment of the high-voltage energy storage device 10 according to the invention for use in a motor vehicle 50 are shown in cross-sectional view.

[0028] Figure 2a This diagram shows a view of the high-voltage energy storage device 10 before the application of force or deformation. In this embodiment, the housing 11 of the high-voltage energy storage device 10 has a housing cover 22 configured in a basin shape and a housing groove 23 also configured in a basin shape, which have sidewalls 21 and together define or define an internal space 12. Battery cells 13, cell contact devices 14 electrically connecting the battery cells 13, and separation devices 15 are disposed in the internal space 12 and secured by means of a medium 16. This medium 16 at least substantially completely fills the internal space 12.

[0029] The separation device 15 is disposed in plane E parallel to the cell contact device 14 of the battery cell 13 and is configured as a planar shape. (As in combination) Figure 1The separation device 15 has a first adhesion coefficient H1 on the first surface 17 and a second adhesion coefficient H2 on the second surface 18. The adhesion coefficient H2 on the surface 18 facing the monomer contact device 14 is greater than the adhesion coefficient H1 on the surface 17 facing away from the monomer contact device 14. Therefore, the adhesive affinity on the surface 18 facing the monomer contact device 14 is greater than that on the surface 17 facing away from the monomer contact device 14, resulting in a higher failure probability at the interface between the first surface 17 and the medium 16 compared to the other surface 18.

[0030] Figure 2b This diagram shows a view of the high-voltage energy storage unit 10 after a force F has been applied to the housing 11 or caused by deformation. The housing 11 or housing cover 22 is shown in a schematic deformed state. Here, the force F is shown to cause movement of the sidewall 21 and / or housing cover 22. Because the adhesion force between the medium 16 and the separation device 15 on the first surface 17 is less than the cohesive force in the medium 16 and / or the adhesion force on the second surface 18 due to the smaller adhesion coefficient H1, relative movement and / or separation of the medium 16 can occur there. This causes failure 20 or breakage in the medium 16, or in this embodiment, the medium 16, together with the housing cover 22, at least partially detaches from the separation device 15, thereby separating the medium 16 also in the area spaced apart from the separation device 15 (in this case, horizontally).

[0031] like Figure 2b As shown, in this embodiment, the medium 16 is separated from the cell contact device 14 at a distance from the cell contact device 14 in the vertical or longitudinal direction of the cell 13. The separation device 15 can therefore be used as a predetermined break point or to provide such a predetermined break point, thereby enabling particularly targeted separation of the medium 16 to improve the protection of the cell contact device 14 and / or the cell 13 and thereby improve the safety of the high-voltage energy storage device 10, especially in the event of deformation caused by an accident.

[0032] List of reference numerals

[0033] 10 High-voltage energy storage device

[0034] 11. Shell

[0035] 12 Interior Space

[0036] 13 battery cells

[0037] 14 Individual contact devices

[0038] 15 Separation device

[0039] 16 Medium

[0040] 17 First Surface

[0041] 18 Second Surface

[0042] 20 Failure Area

[0043] 21 Sidewall

[0044] 22. Housing cover

[0045] 23. Shell groove

[0046] 50 motor vehicles

[0047] E plane

[0048] F force

[0049] H1, H2 adhesion coefficients

Claims

1. A high-voltage energy storage device (10) for a motor vehicle (50) having a plurality of battery cells (13), the battery cells being disposed in an internal space (12) surrounded by a housing (11), the battery cells (13) being fixed in the internal space (12) by means of a medium (16), wherein, The medium (16) has a separation device (15) configured to at least partially separate the medium (16) when a force (F) is applied to the housing (11).

2. The high-voltage energy storage device (10) according to the preceding claim, wherein, The separation device (15) is provided to separate the medium (16) from the cell contact device (14) of the battery cell (13).

3. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) and the cell contact device (14) of the battery cell (13) are disposed separately in the medium (16).

4. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) is disposed between the battery cell (13) and the housing cover (22) of the housing (11).

5. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) is arranged in a plane parallel to the cell contact device (14) of the battery cell.

6. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) is constructed in a planar shape.

7. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) has a first adhesion coefficient (H1) on a first surface (17) and a second adhesion coefficient (H2) on a second surface (18), and the two adhesion coefficients (H1, H2) are different from each other.

8. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The adhesion coefficient (H2) of the surface (18) of the separation device (15) facing the monomer contact device (14) is greater than the adhesion coefficient (H1) of the surface (17) of the separation device (15) away from the monomer contact device (14).

9. The high-voltage energy storage device (10) according to any one of the preceding claims, characterized in that, The separation device (15) has a structure on at least one of its surfaces (17, 18) configured to form a form-locking connection with the medium (16).

10. A motor vehicle (50) having at least one high-voltage energy storage device (10) according to any one of the preceding claims.

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