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US-20260128433-A1 - BATTERY ASSEMBLY HAVING IMPROVED SEALING PROPERTIES AND MOTOR VEHICLE

US20260128433A1US 20260128433 A1US20260128433 A1US 20260128433A1US-20260128433-A1

Abstract

A battery assembly includes a cell group having at least one battery cell which has a releasable cell degassing opening, a carrier plate having a first carrier side, a second carrier side, and a passage area opposite to the releasable cell degassing opening as part of a degassing area of the carrier plate, a protective plate arranged below the carrier plate and facing toward the second carrier side, and a first degassing chamber between the protective plate and the carrier plate. A sealing layer is arranged on the second carrier side covering the degassing area and separates it from the first degassing chamber. A second degassing chamber is formed between the degassing area and the sealing layer to temporarily fluidically separate from the first degassing chamber in case of degassing.

Inventors

  • Martin Dehm
  • Ruben Heid
  • Florian Keller

Assignees

  • AUDI AG

Dates

Publication Date
20260507
Application Date
20251030
Priority Date
20241106

Claims (20)

  1. 1 . A battery assembly for a motor vehicle, comprising: a cell group having at least one battery cell, which has a releasable cell degassing opening, a carrier plate having a first carrier side, having a second carrier side opposite to the first carrier side, and having at least one passage area assigned to the at least one battery cell, wherein the at least one battery cell is arranged on the first carrier side in such a way that the releasable cell degassing opening faces toward the first carrier side and is opposite to the passage area, wherein the carrier plate has a degassing area, in which the passage area is arranged, a protective plate arranged below the carrier plate with respect to a specific direction and facing toward the second carrier side of the protective plate, and a first degassing chamber between the protective plate and the carrier plate, into which, in case of degassing, a gas emerging from the releasable cell degassing opening is introducible through the passage area, wherein the battery assembly comprises a sealing layer which is arranged on the second carrier side and which is joined to the second carrier side to form a seal along at least one closed sealing contour, which extends closed around the degassing area of the carrier plate, and which sealing layer covers the degassing area and separates it from the first degassing chamber, wherein a second degassing chamber is formed between the degassing area and the sealing layer or can be formed in the case of degassing, wherein the battery assembly is designed such that the second degassing chamber is only temporarily fluidically separated from the first degassing chamber in case of degassing, and a fluidic connection is established between the first and second degassing chambers in case of degassing.
  2. 2 . The battery assembly according to claim 1 , wherein the sealing layer is designed as shell-shaped, so that an intermediate space is formed between the sealing layer and the degassing area, which represents the second degassing chamber.
  3. 3 . The battery assembly according to claim 1 , wherein the sealing layer is arranged on the carrier plate in such a way that, in case of degassing, it detaches at least partially from the carrier plate due to temperature and/or pressure, thereby establishing the fluidic connection between the second and first degassing chamber.
  4. 4 . The battery assembly according to claim 1 , wherein the sealing layer is designed such that, in case of degassing, it is at least partially destroyed due to temperature and/or pressure, thereby establishing the fluidic connection between the second and first degassing chamber.
  5. 5 . The battery assembly according to claim 1 , wherein the sealing layer is designed to be dimensionally stable.
  6. 6 . The battery assembly according to claim 1 , wherein the sealing layer is designed to be flexible and/or elastic.
  7. 7 . The battery assembly according to claim 1 , wherein the sealing layer abuts the degassing area and is designed to form the second degassing chamber in case of degassing due to the gas emerging from the cell degassing opening.
  8. 8 . The battery assembly according to claim 1 , wherein the sealing layer is made of a plastic or comprises a plastic.
  9. 9 . The battery assembly according to claim 1 , wherein the cell group comprises multiple battery cells, each of which has a releasable cell degassing opening which is opposite to a respective passage area of the carrier plate, wherein the passage areas are arranged in the degassing area, in particular wherein the battery assembly comprises multiple cell groups, wherein each cell group is assigned to a degassing area of the carrier plate, and each cell group is assigned a sealing layer which is arranged on the carrier plate so as to cover the degassing area of the carrier plate assigned to the cell group.
  10. 10 . A motor vehicle having a battery assembly according to claim 1 .
  11. 11 . The battery assembly according to claim 2 , wherein the sealing layer is arranged on the carrier plate in such a way that, in case of degassing, it detaches at least partially from the carrier plate due to temperature and/or pressure, thereby establishing the fluidic connection between the second and first degassing chamber.
  12. 12 . The battery assembly according to claim 2 , wherein the sealing layer is designed such that, in case of degassing, it is at least partially destroyed due to temperature and/or pressure, thereby establishing the fluidic connection between the second and first degassing chamber.
  13. 13 . The battery assembly according to claim 3 , wherein the sealing layer is designed such that, in case of degassing, it is at least partially destroyed due to temperature and/or pressure, thereby establishing the fluidic connection between the second and first degassing chamber.
  14. 14 . The battery assembly according to claim 2 , wherein the sealing layer is designed to be dimensionally stable.
  15. 15 . The battery assembly according to claim 3 , wherein the sealing layer is designed to be dimensionally stable.
  16. 16 . The battery assembly according to claim 4 , wherein the sealing layer is designed to be dimensionally stable.
  17. 17 . The battery assembly according to claim 2 , wherein the sealing layer is designed to be flexible and/or elastic.
  18. 18 . The battery assembly according to claim 3 , wherein the sealing layer is designed to be flexible and/or elastic.
  19. 19 . The battery assembly according to claim 4 , wherein the sealing layer is designed to be flexible and/or elastic.
  20. 20 . The battery assembly according to claim 5 , wherein the sealing layer is designed to be flexible and/or elastic.

Description

FIELD The invention relates to a battery assembly for a motor vehicle, which comprises a cell group having at least one battery cell that includes a releasable cell degassing opening. In addition, the battery assembly comprises a carrier plate having a first carrier side, having a second carrier side opposite to the first carrier side, and having at least one passage area assigned to the at least one battery cell, wherein the at least one battery cell is arranged on the first carrier side in such a way that the releasable cell degassing opening faces toward the first carrier side and is opposite to the passage area. Furthermore, the battery assembly comprises a protective plate arranged below the carrier plate with respect to a specific direction and facing toward the second carrier side of the protective plate, and a first degassing chamber between the protective plate and the carrier plate, into which, in case of degassing, a gas emerging from the releasable cell degassing opening is introducible through the passage area. Furthermore, the invention also relates to a motor vehicle having such a battery assembly. BACKGROUND Batteries, for example, high-voltage batteries for motor vehicles, often comprise numerous individual cells. Each of these individual cells could suffer a thermal runaway, i.e. run away thermally, due to various causes. The goal in this case is to keep the cells as susceptible as little as possible to such a thermal runaway. For this purpose, specific cell chemistries can be used or cell housings can be designed to be as robust as possible. In addition, cell housings can comprise targeted weak points, also called cell vents, and which are referred to herein as releasable cell degassing openings. These enable targeted outgassing or targeted burnout of the cell in case of a thermal runaway. Other measures can also be used, for example, targeted isolation of the cells from each other, for example by using inter-cell material, by protecting the electrical potential-bearing surfaces, and the like. Such measures can often delay or even stop the propagation of thermal runaway from one cell to other cells. In the case of a stop after the Xth cell thermal runaway, it is also referred to as “stop TP (thermal propagation)”. In the case of a stop after the first cell experiencing thermal runaway, it is also referred to as “No-TP”, which means that no thermal propagation to other cells takes place. In order to enable targeted degassing of a cell experiencing thermal runaway, it is advantageous to connect the cell vent to a degassing volume, which enables targeted discharge and cooling of the harmful gas. Ideally, the connection should be such that the cell experiencing thermal runaway is not blocked in its outgassing behavior. A blockage of the cell experiencing thermal runaway at the cell vent could result in unwanted burnout at other cell positions. To provide the freest possible degassing of a cell experiencing thermal runaway and the removal of the harmful gas via a degassing volume, openings or interfaces can be created between the degassing chamber and the cell vent. Free degassing into the surroundings instead of into a degassing chamber is undesirable due to the high oxygen content in the surroundings and the resulting immediate fire in the vehicle surroundings. These interfaces or openings between the cell and the degassing chamber can, for example, be implemented as a perforated plate, in which each cell sits cut out on a plate in the area of the cell vent. Larger cutouts across a larger number of cells are also possible. If the cell vents are directed downwards with respect to a vehicle vertical direction, in particular the space above the underrun protection of the motor vehicle can be used as a degassing chamber. However, the difficulty here is that the battery compartment, in which the battery cells are located, has to be reliably protected against the entry of water, dust, contaminants, and the like, but the underrun protection is directly adjacent to the surroundings of the motor vehicle and is therefore particularly susceptible to apotential entry of water or dirt or the like. Sealing off the underrun protection from the battery is particularly difficult due to the size of the battery and the corresponding size of the underrun protection. Sealing in the area of the cells or through openings is also not easy to implement, since it must be ensured that the cells can degas freely and are not blocked by waterproof structures directly on the cells. Conversely, sealing structures cannot be made excessively thin, so as not to lose their sealing effect over their service life. Due to the large geometry of the battery, component tolerances, reversible and irreversible cell growth, thermal influences, driving movements, and the like, the tightness of the high-voltage battery has heretofore only been able to be achieved with enormous effort. DE 10 2022 121 801 A1 describes a battery having batt