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EP-4740260-A1 - BATTERY ARRANGEMENT WITH IMPROVED THERMAL INSULATION

EP4740260A1EP 4740260 A1EP4740260 A1EP 4740260A1EP-4740260-A1

Abstract

The invention relates to a battery arrangement (10), in particular for use in electric vehicles, comprising two or more battery units (12a, 12b), wherein a flat separating element (14) that is arranged at least between two adjacent battery units (12a, 12b) separates the battery units (12a, 12b) from one another at least in some portions and comprises: i) an element core (16) comprising a first core layer (18), wherein a mass fraction of 70% or more of the first core layer (18) consists of porous, amorphous silicon dioxide, based on the mass of the core layer (18); ii) a plastic sheath (20) encasing the element core (16) and comprising a plastic material.

Inventors

  • NIES, KLAUS-DIETER

Assignees

  • NIES, Klaus-Dieter

Dates

Publication Date
20260513
Application Date
20250429

Claims (15)

  1. 1. Battery arrangement (10), in particular for use in electric vehicles, comprising two or more battery units (12a, 12b), wherein at least between two adjacent battery units (12a, 12b) a planar separating element (14) is arranged which separates the battery units (12a, 12b) at least sectionally from each other, wherein the planar separating element (14) comprises: i) an element core (16) comprising a first core layer (18), wherein the first core layer (18) consists of porous, amorphous silicon dioxide to a mass fraction of 70% or more, based on the mass of the core layer (18), ii) a plastic sheath (20) encasing the element core (16), comprising a plastic material.
  2. 2. Battery arrangement (10) according to claim 1, wherein the battery units (12a, 12b) are prismatic cells or comprise prismatic cells.
  3. 3. Battery arrangement (10) according to one of claims 1 or 2, wherein the porous, amorphous silicon dioxide is selected from the group consisting of precipitated silicon dioxide, pyrogenic silicon dioxide and silicate nanogel.
  4. 4. Battery arrangement (10) according to one of claims 1 to 3, wherein the first core layer (18) consists of porous, amorphous silicon dioxide to a mass fraction of 80% or more.
  5. 5. Battery arrangement (10) according to one of claims 1 to 4, wherein the plastic material comprises one or more thermoplastic polymers.
  6. 6. Battery arrangement (10) according to one of claims 1 to 5, wherein the plastic casing (20) forms an interior space, wherein the element core (16) is arranged in the interior space.
  7. 7. Battery arrangement (10) according to one of claims 1 to 6, wherein the separating element has a pressure of less than 100 kPa at 23 °C inside the plastic casing (20).
  8. 8. Battery arrangement (10) according to one of claims 1 to 7, wherein the element core (16) comprises at least a second core layer (22), wherein the second core layer (22) is selected from the group consisting of elastomeric sheet materials, plastic foams, textile sheet structures and spacer textiles.
  9. 9. Vehicle comprising an electric motor and at least one battery arrangement (10) according to any one of claims 1 to 8.
  10. 10. Method for manufacturing a battery arrangement (10) according to any one of claims 1 to 8, comprising the process steps: a) manufacturing or providing the element core (16), comprising the first core layer (18), and b) coating the element core (16) with a plastic material to obtain the plastic shell (20).
  11. 11. Method according to claim 10, wherein the production of the element core (16) in process step a) comprises the compression of a particulate, porous, amorphous silicon dioxide.
  12. 12. Method according to one of claims 10 or 11, wherein the production of the element core (16) in process step a) comprises separating the first core layer (18) from a starting block.
  13. 13. Method according to any one of claims 10 to 12, wherein the production of the element core (16) in process step a) comprises arranging the first core layer (18) relative to a second core layer (22), wherein the second core layer (22) is selected from the group consisting of elastomeric sheet materials, plastic foams and textile sheet structures.
  14. 14. Method according to one of claims 10 to 13, wherein the coating of the element core (16) with the plastic material takes place in a laminating device or a film sealing device.
  15. 15. A method according to any one of claims 10 to 14, wherein the coating of the element core with the plastic material is carried out at a pressure of less than 100 kPa. ```

Description

Battery arrangement with improved thermal insulation Description The invention relates to a battery arrangement, particularly for use in electric vehicles, a method for manufacturing such battery arrangements, and a vehicle comprising a corresponding battery arrangement. The invention also discloses the use of a specific planar separating element for the thermal insulation of two or more battery units in a battery arrangement. In recent years, as awareness grows for a more sustainable use of fossil resources and the avoidance of greenhouse gas emissions, the improvement of electric vehicles and the development of new concepts for electromobility have increasingly become the focus of many industries. A key component of electric vehicles, which in many cases is largely responsible for the distances achievable with the vehicle, is the battery system used to store electrical energy, and consequently, a great deal of research and development effort is focused on this. Modern battery systems for electric vehicles usually consist of a large number of electrically interconnected battery units, for example, in the form of so-called pouch cells or so-called prismatic cells. These battery units contain within them the components of the respective electrochemical cells, which serve for the electrochemical storage of energy. The individual battery units, which can be, for example, lithium-ion batteries, represent chemically complex and comparatively failure-prone systems in which at least partially exothermic reactions occur during cycling. Such battery units are susceptible to malfunctions, especially since they often contain flammable substances, particularly electrolytes, and high temperatures can occur during operation. Consequently, in the worst-case scenario, a battery unit can experience thermal runaway. In such a thermal runaway, in addition to a possible pressure buildup within the battery unit, a significant temperature increase and possibly even flame formation occur in most cases. Thermal runaway in a battery unit can potentially trigger a chain reaction, in which the temperature increase of a defective battery unit disrupts the fragile equilibrium of neighboring battery units and also triggers thermal runaway in them. For this reason, battery units in appropriate battery configurations are often separated from each other by separating elements, which must ensure the best possible thermal insulation between the battery units in order to prevent or at least slow down a thermal runaway chain reaction in the event of an incident. Since thermal runaway can also lead to flame formation, the separating elements must, in most cases, be fire-resistant to prevent them from acting as flammable material themselves in the event of a malfunction and further accelerating the chain reaction. Accordingly, the separating elements should also provide fire-resistant compartmentation. The specific requirements for the separating elements used vary depending on the design of the battery cells. One challenge with pouch cells is that they undergo volume changes even during normal operation, which are transmitted to the environment through the typically flexible casing of the battery units. Many commercially available pouch cell batteries undergo such volume changes, particularly during charging and discharging – a process that occurs very frequently over the lifespan of a battery array and, especially during charging, on a relatively short timescale. This places particular demands on the deformability of the separating elements and their ability to undergo reversible volume changes. For prismatic cells, the volume change of the battery units due to the cell casings is usually not a critical criterion that needs to be considered when designing separators. However, prismatic cells are often more difficult to cool than pouch cells. At the same time, the housing of the prismatic cells already occupies a considerable amount of installation space and is associated with increased weight, which can negatively affect the energy density of the battery unit and can also lead to higher manufacturing costs. Accordingly, the requirements for separators for prismatic cells are primarily that they exhibit the best possible thermal insulation properties in the smallest possible installation space and allow for reliable fire compartmentation even with a small thickness and low weight. It is also desirable that the manufacturing costs for the separators be kept as low as possible to avoid significantly increasing the overall costs. According to the inventor, the separating elements for prismatic cells available in the prior art do not satisfactorily resolve the existing conflict of objectives: i) good thermal insulation and sufficient fire protection, ii) low weight and small space requirements, and iii) simple, fast and cost-effective manufacturing. Furthermore, although many of the separation elements known from the prior art exhibit satisfacto