DE-102024133119-A1 - High-voltage battery for a motor vehicle

Abstract

The invention relates to a high-voltage storage device (10) for a motor vehicle, comprising a plurality of battery cells (12) arranged in a cell assembly (11) and electrically connected, wherein the battery cells (12) are stored in the high-voltage storage device (10) in such a way that, by means of energy (E) that can be released in the event of thermal runaway of a battery cell (12), a separation of the electrical connection of this battery cell (12) from the cell assembly (11) can be effected.

Inventors

• Sascha Zimmermann
• Kevin Czyrka
• Joseph Endres
• Franz Fuchs
• Felix Laasch
• Michael Lienerth
• Ferdinand Sparrer

Assignees

• BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT

Dates

Publication Date

20260513

Application Date

20241113

Claims (10)

1. High-voltage storage device (10) for a motor vehicle, comprising a plurality of battery cells (12) arranged in a cell assembly (11) and electrically connected, wherein the battery cells (12) are mounted in the high-voltage storage device (10) in such a way that, by means of energy (E) that can be released in the event of thermal runaway of a battery cell (12), a displacement (V) of this battery cell (12) can be effected in order to separate the electrical to effect the connection of this battery cell (12) from the cell assembly (11).
2. High-voltage storage device (10) according to the preceding claim, wherein, in addition, an energy (E) that can be released in the event of a secondary short circuit (E K ) occurring on the basis of thermal runaway can be used to displace (V) the battery cell (12).
3. High-voltage storage device (10) according to the preceding claim, wherein the battery cells (12) are mounted in the high-voltage storage device (10) by means of a structural medium (14) and the structural medium (14) is configured to change in such a way as to allow a displacement (V) of this battery cell (12) when exposed to the releaseable energy (E).
4. High-voltage storage device (10) according to one of the preceding claims, wherein the displacement can take place substantially along a longitudinal axis (L) of the battery cell (12).
5. High-voltage storage device (10) according to one of the preceding claims, wherein the battery cells (12) are axially mounted by means of the structural medium (14) and this mounting is detachable when the releasable energy (E G ) is applied.
6. High-voltage storage device (10) according to one of the preceding claims, wherein the battery cells are radially mounted by means of the structural medium (12) and this mounting is detachable when the releasable energy (E T ) is applied.
7. High-voltage storage device (10) according to one of the preceding claims, wherein the structural medium (14) is configured to cause a pressure increase (D) when the releasable energy (E T ) is applied, in order to displace the battery cell (12).
8. High-voltage storage device (10) according to one of the preceding claims, wherein the battery cells (12) are electrically connected by means of a cell contacting device (15) and the cell contacting device (15) is configured to release the displacement (V) of the battery cell (12) when the releasable energy (E) is applied.
9. High-voltage storage device (10) according to the preceding claim, wherein the displacement is possible essentially in one direction away from the cell contacting device (15).
10. High-voltage storage device (10) according to one of the preceding claims, wherein the cell contacting device (15) is arranged on the battery cells (12) such that it can be disconnected at at least one contact point with the battery cell (12) when the releasable energy (E) is applied. [SZ1][VE2]

Description

The invention relates to a high-voltage storage device for a motor vehicle, comprising a plurality of battery cells arranged in a cell assembly and electrically connected, wherein the battery cells are stored in the high-voltage storage device in such a way that, by means of energy that can be released in the event of thermal runaway of a battery cell, a separation of the electrical connection of this battery cell from the cell assembly can be effected. High-voltage storage devices, also known as traction batteries or accumulators, are used to provide electrical energy for powering electric motors in motor vehicles. These high-voltage storage devices typically consist of an arrangement of battery cells connected in parallel and series via a contacting device, all housed within a casing. The battery cells and the contacting device are typically encased or encapsulated in an adhesive structural foam to create a uniform structure and provide thermal and/or electrical insulation. For example, if a battery cell is damaged and/or the current-carrying contact system detaches from a battery cell, unwanted and safety-critical short circuits and/or thermal events can occur, which in the worst case can spread to neighboring battery cells. Against this background, an object of the invention is to improve a high-voltage storage device for a motor vehicle. In particular, the high-voltage storage device is to be improved in such a way as to enable increased safety, especially in the event of damage and/or a malfunction of a battery cell of the high-voltage storage device. This problem is solved by a high-voltage storage device for a motor vehicle having the features of claim 1. The dependent claims relate to advantageous further developments of the invention. According to a first aspect, a high-voltage storage device for a motor vehicle is described, comprising a plurality of battery cells arranged in a cell assembly and electrically connected. The battery cells are mounted, particularly mechanically, within the high-voltage storage device in such a way that, by means of energy released during thermal runaway of a battery cell, a displacement of this battery cell can be effected in order to disconnect its electrical connection from the cell assembly. This interrupts short-circuit currents that can flow from the damaged battery cell to another battery cell, thus preventing propagation and/or progressive damage to the high-voltage storage device. The cell environment or the (mechanical) mounting of the battery cell(s) is designed such that, in the event of a defect or thermal runaway, it provides space or degrees of freedom for the battery cell to detach from the system. In this context, the (cell) environment is understood to mean, in particular, mechanical or physical contact points and/or areas, such as a connection to a structural medium, a heat exchange system, a cell contacting device, and/or neighboring cells, which provide mechanical mounting for the battery cell(s). Various degradation effects can be utilized in this process. For example, gas evolution or degassing associated with thermal runaway of a battery cell can rupture a mechanical environment, especially in the form of a structural medium. In some embodiments, the thermal runaway can even cause the structure to be blown away. Heat or thermal energy generated during thermal runaway can at least partially melt and/or alter the environment around the affected battery cell in such a way that a supporting effect of the environment or the structural medium, in particular radial and/or axial support, is degraded or lost. A high-voltage storage system is, in particular, an energy storage device or traction battery for a motor vehicle, comprising several battery cells arranged in one or more cell packs or cell assemblies. The housing of the high-voltage storage system defines an interior space in which the battery cells are contained or arranged. Cylindrical battery cells are primarily used, which can be provided in a pack arrangement or cell assemblies. A cylindrical battery cell can, for example, have a circular cell cross-section and a longitudinal axis perpendicular to it, and can be bounded longitudinally by two end faces, which are connected by a cell shell or surface. In an installation situation in a motor vehicle, the high-voltage storage system and/or the battery cells can be arranged such that the longitudinal axes of the battery cells are parallel to a vehicle vertical. Of course, prismatic battery cells and/or battery cells with other cross-sections, such as rectangular, hexagonal, or prismatic cross-sections, can also be used. Typically, such a battery cell has a geometrically recessed or slightly raised first electrical pole or cell terminal on one of its end faces or first side for electrical contact via the cell contacting device. The remaining part of the end face or first side, as well as the cell shell of the battery cell, can form the second ele