Battery arrangement having a three-dimensional plastic structure as a separating element

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 or consists of an elastically deformable, three-dimensional plastic structure (16), the three-dimensional plastic structure (16) being: i) a macroscopically structured structural element comprising or consisting of a thermoplastic elastomer, or ii) a corrugated and / or bent and / or edged film element comprising or consisting of a thermoplastic material, wherein the three-dimensional plastic structure (16) is designed such that a plurality of fluid guiding channels (18) are formed between the three-dimensional plastic structure (16) and at least one of the battery units (12a, 12b).

Description

[0001] Battery arrangement with three-dimensional plastic structure as a separating element

[0002] Description

[0003] The invention relates to a battery arrangement, particularly for use in electric vehicles, and a method for dealing with a malfunction in such a battery arrangement. A vehicle comprising a corresponding battery arrangement is also disclosed.

[0004] 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.

[0005] A key component of electric vehicles, often decisive for the vehicle's range, is the battery system used to store electrical energy, which is the focus of considerable research and development. Modern battery systems for electric vehicles typically consist of numerous electrically interconnected battery units, such as pouch cells or prismatic cells. These battery units contain the components of the respective electrochemical cells responsible for the electrochemical storage of energy.

[0006] 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.

[0007] 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.

[0008] Since thermal runaway can also lead to flame formation, the separating elements must, in most cases, be sufficiently fire-resistant or durable to prevent themselves from acting as combustible material in the event of a malfunction and further accelerating the chain reaction. Accordingly, in the state of the art, the separating elements should generally also provide fire-resistant compartmentation. The specific requirements for the separating elements used vary depending on the design of the battery cells.

[0009] 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 battery units undergo such volume changes, in addition to an inherent growth of up to 15% over their lifetime, depending on the cell chemistry. This occurs particularly during charging and discharging, a process that happens 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 over the course of the overall compression, depending on the stage of the battery lifecycle.

[0010] For prismatic cells, the volume change of the battery units due to the cell housings is often a less critical criterion that must be considered when designing separating elements. However, prismatic cells are sometimes 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 the separating elements for prismatic cells are primarily that they exhibit the best possible thermal insulation properties in the smallest possible installation space and allow reliable fire protection even with low thickness and low weight, whereby it is desirable that the costs for the production of the separating elements can be kept as low as possible in order not to increase the overall costs too much.

[0011] Regardless of the design of the battery cells, there is a regular requirement that the battery cells of the battery arrangement are sufficiently stabilized and fixed relative to each other by the separating elements used, so that they are protected against mechanical stresses.

[0012] As a result of the strong cost pressure in the automotive sector, there is a particular need for such separating elements, which can be manufactured in a particularly time- and therefore cost-efficient manner and, in particular, can be produced as efficiently as possible in large quantities.

[0013] According to the inventor, the separating elements available in the prior art do not meet the diverse requirements in many cases, or not completely.

[0014] The purpose of the present invention was to eliminate or at least mitigate the disadvantages of the prior art.

[0015] In particular, it was an object of the present invention to provide a battery arrangement in which the battery units are protected as well as possible from the spread of thermal runaway by a separating element.

[0016] One object of the present invention was to provide a battery arrangement in which the battery units are thermally isolated from each other as effectively as possible by a separating element and are protected from flame formation by the surrounding battery units by excellent fire-resistant sealing.

[0017] In this respect, it was a desirable requirement of the present invention that the separating element used should be able to achieve the advantageous protective effects even with small thicknesses and low weights, in order to enable battery arrangement designs with advantageous space requirements and low weight.

[0018] Furthermore, it was an object of the present invention to provide a battery arrangement in which the battery units are efficiently stabilized and fixed relative to one another by a separating element, so that they are protected against mechanical stresses by efficient damping. Fundamentally, it was an important object of the present invention that the battery arrangement and the separating element used should be particularly time- and cost-efficient to manufacture.

[0019] Furthermore, one objective of the present invention was to enable the battery cells installed therein to be cooled and, if necessary, even temperature-controlled in a particularly efficient manner.

[0020] It was a complementary object of the present invention to provide an advantageous method for manufacturing corresponding battery arrangements, with which the battery arrangements to be specified can be obtained in a particularly cost-efficient manner and, in particular, also in particularly lightweight designs.

[0021] At the same time, it was a complementary objective of the present invention that the solution to be specified should, in the event of a malfunction, preferably offer a possibility for efficient protection against thermal runaway and the associated dangers.

[0022] It was a secondary object of the present invention to specify a vehicle which includes the battery arrangement to be specified.

[0023] The inventor of the present invention has found that the problems described above can be solved if a specific separating element is used in a battery arrangement with two or more electrically connected battery units, which is designed as a macroscopically structured 3D element made of a thermoplastic elastomer or as a film made of a thermoplastic or thermosetting plastic formed into a three-dimensional shape, as defined in the claims.

[0024] Surprisingly, the use of suitable separating elements in battery units allows for a particularly advantageous resolution of the conflicting objectives of good thermal insulation and sufficient fire protection on the one hand, and low weight and compact size on the other. The quality of the solution to this conflict is especially advantageous in relation to the advantageously low manufacturing costs, the high availability of the required materials, and the time efficiency with which the separating elements can be produced. Furthermore, the separating elements can be advantageously manufactured in a particularly time- and cost-efficient manner using tube extrusion in the inventive process, thereby enabling advantageously thin walls.

[0025] Based on the premise that a battery cell cannot be reused after thermal runaway, the inventor developed the concept of utilizing the advantageous structure of the specific separating elements to achieve significant benefits in the application of active firefighting measures. The open and accessible structure of the gaps formed between the separating elements and the battery cells allows for particularly efficient filling of the spaces between two battery cells with a fire-fighting fluid, such as a fire-fighting foam, to ensure the necessary containment of thermal runaway in the event of a malfunction.

[0026] Additionally or alternatively, the advantageous structure of the separating elements can also be used to fill the spaces with inorganic insulating materials, in particular particulate insulating materials.

[0027] The aforementioned problems are solved accordingly by the subject matter of the invention as defined in the claims. Preferred embodiments of the invention are described in the dependent claims and the following descriptions.

[0028] Such embodiments, which are hereinafter referred to as preferred, are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments referred to below as particularly preferred are therefore especially preferred. Also preferred are embodiments in which a feature of one embodiment, referred to as preferred to any extent, is combined with one or more further features of other embodiments, which are referred to as preferred to any extent. Features of preferred vehicles and methods result from the features of preferred battery arrangements.

[0029] Particularly preferred embodiments of the invention are disclosed in the exemplary embodiments. Against this background, particularly preferred embodiments of the invention have two or more, preferably three or more, and most preferably four or more, of the preferred features of the invention disclosed below, which are also implemented in the exemplary embodiments.

[0030] The invention relates to a battery arrangement, in particular for use in electric vehicles and stationary applications, comprising two or more battery units, wherein a separating element is arranged at least between two adjacent battery units, which separates the battery units from each other at least section by section, wherein the separating element comprises or consists of an elastically deformable, three-dimensional plastic structure, wherein the plastic structure: i) comprises or consists of a macroscopically structured structural element made of a thermoplastic elastomer, or ii) comprises or consists of a corrugated and / or folded and / or bent film element made of a thermoplastic plastic, wherein the three-dimensional plastic structure is designed such that a plurality of fluid guidance channels are formed between the three-dimensional plastic structure and at least one of the battery units.

[0031] Battery arrangements are generally well known to those skilled in the art. The battery arrangement according to the invention is particularly suitable for use in electric vehicles and their battery systems. However, the specific battery arrangements are also suitable for use in other vehicles, especially rail vehicles such as trains, and also for use in the power supply of stationary installations.

[0032] The major advantages of the battery arrangements according to the invention arise in particular from the specific design of the separating element. Accordingly, the battery arrangements according to the invention are not, in principle, limited with regard to the cell chemistry in the battery units, with the use of lithium-ion batteries being preferred due to their high industrial relevance.

[0033] To provide an electric vehicle with the necessary energy, the battery units in corresponding battery arrangements are regularly electrically connected to one another, with the charging and discharging of the resulting cell stack often being controlled by a battery control unit. A typical example is a battery arrangement according to the invention in which the battery units are connected in parallel and / or in series.

[0034] A typical battery arrangement according to the invention is also one in which the battery arrangement is arranged in a housing and / or in which the battery arrangement is surrounded by a protective casing.

[0035] In accordance with the skilled person's understanding, the battery units of the battery arrangement according to the invention can be individual battery cells, each separated by separating elements, or packs of several individual battery cells, which are either not separated from each other or only separated by alternative separating elements, for example, made of silicone foam. However, with regard to the safety of the resulting battery arrangement, the inventor considers it particularly advantageous if individual battery cells or only pairs of battery cells are separated by appropriate separating elements. An exemplary battery arrangement according to the invention is thus one in which the battery units comprise a battery cell or two or more electrically connected battery cells, preferably a single battery cell.Of particular relevance is a battery arrangement according to the invention, wherein the battery units are pouch cells and / or prismatic cells, or comprise pouch cells and / or prismatic cells, wherein, within the scope of the present invention, prismatic cells also include cylindrical cells. Prismatic cells, in particular, benefit from their good cooling properties. A particular advantage of the present invention is that the specific separating elements, especially the foil element and the tubular extruded structural elements, are particularly suitable for use with cylindrical cells, which, within the scope of the present invention, are classified as prismatic cells. In practice, the specific separating elements of the present invention are thus particularly suitable for separating prismatic cells from one another.A battery arrangement according to the invention is preferred, wherein the battery units are prismatic cells or comprise prismatic cells, preferably cylindrical cells.

[0036] The very rapid cooling is also advantageous for pouch cells, since in this case low thermal conductivity is not required to prevent the foil separators in the neighboring cell from melting in the event of thermal runaway. Accordingly, a battery arrangement according to the invention is preferred for many applications, wherein the battery units are pouch cells or comprise pouch cells.

[0037] In practice, such battery arrangements typically comprise a plurality of battery units and a complementary number of separating elements. A typical battery arrangement according to the invention therefore includes four or more, preferably six or more, electrically interconnected battery units, and / or three or more, preferably five or more, separating elements.

[0038] A key aspect of the present invention is the use of an elastically deformable, three-dimensional plastic structure as a separating element.

[0039] The elastic deformability allows for optimal fitting of the separating element between the battery units as well as advantageous stabilization of the resulting battery arrangement, in which the battery units are particularly well protected against mechanical stresses.

[0040] Furthermore, the three-dimensional plastic structure is designed such that a plurality of fluid guide channels are formed between the three-dimensional plastic structure and at least one of the battery units, preferably both adjacent battery units. These fluid guide channels advantageously allow for particularly efficient cooling of the battery units, enable a very lightweight overall construction, can be filled with particulate insulating material to optimize thermal insulation properties, and, in particular, allow the implementation of the advantageous method according to the invention for handling a malfunction in the battery arrangement.

[0041] Furthermore, the three-dimensional plastic structure is inherently thermoplastically deformable, which allows the three-dimensional plastic structure to be manufactured in a particularly time- and cost-efficient manner.

[0042] The combination of elastic deformability and the formation of fluid guidance channels can be achieved in one of two ways within the scope of the present invention, which will be described in more detail below.

[0043] Firstly, a structural element comprising or consisting of a thermoplastic elastomer can be used, which, in the inventors' opinion, is preferred for the vast majority of cases. Accordingly, a battery arrangement according to the invention is preferred for most applications, wherein the three-dimensional plastic structure is a macroscopically structured structural element comprising or consisting of a thermoplastic elastomer.

[0044] In this case, the elastic properties are achieved through the static design and inherent material properties of the material used, while the formation of the fluid channels is achieved through the macroscopic surface structuring of the structural element. Thermoplastic elastomers, often abbreviated as TPE, are generally known to those skilled in the art and are commercially available from various suppliers. At room temperature, such thermoplastic elastomers exhibit mechanical properties comparable to those of typical elastomers, especially rubber materials, particularly the property of elastic deformation. The term "thermoplastic," however, indicates that, unlike conventional elastomers, TPE plastics exhibit thermoplastic behavior at elevated temperatures, meaning they can be plastically deformed at high temperatures.Thermoplastic elastomers are often copolymers or block copolymers, in which the individual copolymer components are responsible for the different behavior at various temperatures. Among the possible thermoplastic elastomers, the inventor has identified the use of thermoplastic silicone elastomers, i.e., thermoplastic elastomers based on polysiloxanes, e.g., polydimethylsiloxane-polyurea copolymers, as particularly advantageous, since these offer not only excellent mechanical properties but also very advantageous insulating and fire-resistant properties.A preferred battery arrangement according to the invention is wherein the thermoplastic elastomer is selected from the group consisting of thermoplastic silicone elastomers, thermoplastic polyamide copolymers, thermoplastic polyester copolymers, thermoplastic styrene copolymers, thermoplastic urethane copolymers, uncrosslinked thermoplastic poly-olefin blends, dynamically crosslinked thermoplastic poly-olefin blends and thermoplastic fluoroelastomers, preferably selected from the group consisting of thermoplastic silicone elastomers.

[0045] Thermoplastic elastomers in general and thermoplastic silicone elastomers are commercially available from various suppliers, for example from the company Wacker under the trade name Elastosil.

[0046] The desired formation of the fluid guide channels is achieved through the macroscopic structuring of the structural elements. In accordance with the skilled person's understanding, the term "macroscopically structured" means that the structural element is structured such that it has protrusions and depressions, with a distance of more than 0.1 mm, preferably more than 0.2 mm, and particularly preferably more than 0.5 mm, between the tips of the protrusions and the bottoms of the depressions. Accordingly, the macroscopic structuring of the structural element is visible to the naked eye. The skilled person readily understands that the structuring should not be too pronounced, however, in order to comply with the usual standards in the field of technology.It is therefore preferred that the distance between the tip of the protrusions and the bottom of the depressions is in the range of 0.1 to 12 mm, preferably in the range of 0.2 to 8 mm, and particularly preferably in the range of 0.5 to 4 mm.

[0047] The macroscopic structuring can result from a wavy and / or bent guide of the structural element or be achieved by providing a straight base body with elevations, whereby this can also be combined.

[0048] A preferred option is a battery arrangement according to the invention, wherein the macroscopically structured structural element is a corrugated and / or bent structural element, wherein the structured structural element preferably has the shape of a periodic function in cross-section, particularly preferably a sawtooth function, a sine function, a triangular function, a dovetail function or a rectangular function.

[0049] A battery arrangement according to the invention is preferred, either additionally or alternatively, wherein the macroscopically structured structural element comprises a plurality of structural protrusions arranged on the surface of the structural element, wherein the structural protrusions are preferably designed as elongated structural protrusions, wherein the elongated structural protrusions are particularly preferably arranged substantially parallel to one another on the surface of the structural element, and most preferably substantially equidistantly. A battery arrangement according to the invention is particularly preferred in which the structural protrusions are arranged on both sides of the surface of the structural element, preferably alternating.

[0050] A battery arrangement according to the invention is particularly preferred, wherein the structural protrusions have a maximum height relative to the surface of the structural element in the range of 0.2 to 6 mm, preferably in the range of 0.5 to 5 mm, and particularly preferably in the range of 0.7 to 4 mm. Additionally or alternatively, a battery arrangement according to the invention is also particularly preferred, wherein the structural protrusions have a rectangular or triangular cross-section, preferably a triangular cross-section, transverse to their greatest longitudinal extent.

[0051] The structural elements usable according to the invention can advantageously be obtained by extrusion, wherein the macroscopic structuring can advantageously be directly imprinted or embossed during extrusion. The inventor has identified tube extrusion as particularly preferred, since very thin layer thicknesses of the structural elements can be obtained particularly reliably by tube extrusion. A battery arrangement according to the invention is therefore particularly preferred, wherein the macroscopically structured structural element is produced or producible by extrusion of the thermoplastic elastomer, particularly preferably by tube extrusion of the thermoplastic elastomer, wherein the macroscopic structuring is preferably formed by the extrusion die.

[0052] A preferred battery arrangement according to the invention is one in which the structural element has a medium thickness in the range of 0.5 to 12 mm, preferably in the range of 1.0 to 8 mm, and particularly preferably in the range of 1.5 to 4 mm.

[0053] Although it would potentially be conceivable to include other components besides the thermoplastic elastomer in the macroscopically structured structural elements, for example, a metallic reinforcing structure, the inventors consider it particularly preferable to form the macroscopically structured structural element as largely as possible from the thermoplastic elastomer. Accordingly, a battery arrangement according to the invention is preferred in which the macroscopically structured structural element consists of the thermoplastic elastomer to a mass fraction of 80% or more, preferably 90% or more, particularly preferably 95% or more, most preferably 99% or more, and most preferably essentially 100%.

[0054] As an alternative to the macroscopically structured structural elements disclosed above, the present invention offers the use of a corrugated and / or folded film element comprising or consisting of a thermoplastic material, which is particularly preferred with regard to manufacturing effort and costs. For some applications, a battery arrangement according to the invention is therefore preferred, wherein the three-dimensional plastic structure comprises or consists of a corrugated and / or folded film element made of a thermoplastic material.

[0055] In this case, the desired elasticity of the three-dimensional plastic structure is achieved through the specific arrangement of a thermoplastic film that is inherently inelastic or essentially non-elastic. A macroscopic structure is created from the film by forming it in a wave-like pattern and / or by folding it, which not only achieves the desired elasticity but also synergistically forms the necessary fluid channels.

[0056] For the film element, a wide range of conventional thermoplastic films can advantageously be used. A battery arrangement according to the invention is preferred, wherein the thermoplastic is selected from the group consisting of polyolefins and polyesters, preferably polyethylene, polypropylene, and polyethylene terephthalate.

[0057] Especially with regard to overall costs and manufacturing effort, it can be advantageous to manufacture the film elements as largely as possible from the thermoplastic material. In this case, a battery arrangement according to the invention is preferred, wherein the film element consists of a mass fraction of 80% or more, preferably 90% or more, particularly preferably 95% or more, most preferably 99% or more, and most preferably substantially 100%, of the thermoplastic material.

[0058] Furthermore, the use of films made of composite materials is also conceivable, particularly for demanding applications. These films may include one or more plastics as well as other components, such as layered silicates. A battery arrangement according to the invention is preferred in this case, wherein the film element is a film made of a composite material consisting of at least two different materials, and the film element preferably comprises a layered silicate film, in particular an alumina-silicate film, or a laminated textile fabric, in particular a nonwoven.

[0059] A preferred battery arrangement according to the invention has a film thickness in which the film element has a mean film thickness in the range of 20 to 1000 pm, preferably in the range of 50 to 500 pm, and particularly preferably in the range of 100 to 250 pm.

[0060] The inventor considers it advantageous to generate a largely periodic fold, crease, or bend even for the corrugated, folded, and / or bent foil element. A battery arrangement according to the invention is therefore preferred, wherein the foil element has the cross-sectional shape of a periodic function, preferably a sawtooth function, a sine function, a triangular function, a dovetail function, or a rectangular function, wherein, within the scope of the present invention, even slight deviations from 90° angles, in particular by 1° or less, preferably 0.5° or less, are still considered a rectangular function.

[0061] With regard to the extent of the structuring, the inventor considers a battery arrangement according to the invention to be preferred, wherein the distance between adjacent maxima and minima of the corrugated and / or bent and / or folded foil element is in the range of 0.8 to 6 mm, preferably in the range of 1.2 to 5 mm, particularly preferably in the range of 1.6 to 4 mm.

[0062] Through extensive testing, the inventor has succeeded in identifying preferred dimensions for the separating element, which are specified via the enclosing surface to take the macroscopic structure into account. A preferred battery arrangement according to the invention is one in which the separating element has an area of ​​300 to 1000 cm² on one of the flat sides of the enclosing surface of the separating element. 2 preferably in the range of 120 to 650 cm 2, has. Preferably, or alternatively, a battery arrangement according to the invention is used, wherein the enclosing end of the separating element has a mean thickness in the range of 1 to 15 mm, preferably in the range of 1.5 to 10 mm, particularly preferably in the range of 2 to 5 mm.

[0063] Those skilled in the art understand that the dimensions of the fluid guide channels designed according to the invention depend significantly on the design of the plastic structure, the compressibility of the material used, and, in particular, the tension with which the battery cells are pressed against each other. According to the inventor, a battery arrangement according to the invention is preferred in which the fluid guide channels have a maximum cross-sectional diameter in the range of 0.05 to 5 mm, preferably in the range of 0.1 to 4 mm, and particularly preferably in the range of 0.2 to 3 mm. A battery arrangement according to the invention is also preferred, or alternatively, in which a plurality of fluid guide channels are formed between the three-dimensional plastic structure and each of the two battery units.

[0064] A major advantage of the present invention is that the deformation and recovery properties of the three-dimensional plastic structure can be very precisely controlled via material selection and structure, which can also be advantageously simulated using simulation software. In this respect, the inventor has succeeded in identifying optimized compression hardness values, measured according to DIN EN ISO 3386-2:2010-09, with which separating elements are obtained that are ideally suited for use in vehicle battery assemblies and are particularly well-suited to the volume changes of typical lithium-ion battery pouch cells. It is advantageous to specify a compression hardness value for different compressions in order to define the most desirable parameter range.A preferred battery arrangement according to the invention is one in which the plastic structure has an effective compression hardness of deformation to 90% of the initial thickness in the range of 1 to 100 kPa, preferably in the range of 5 to 80 kPa, and particularly preferably in the range of 8 to 60 kPa. A preferred additional or alternative battery arrangement according to the invention is one in which the plastic structure has an effective compression hardness of deformation to 40% of the initial thickness in the range of 5 to 300 kPa, preferably in the range of 20 to 250 kPa, and particularly preferably in the range of 25 to 200 kPa. A preferred additional or alternative battery arrangement according to the invention is one in which the plastic structure has an effective compression hardness of deformation to 20% of the initial thickness in the range of 15 to 350 kPa, preferably in the range of 25 to 300 kPa, and particularly preferably in the range of 35 to 250 kPa.A battery arrangement according to the invention is also preferred, or alternatively, wherein the plastic structure has an effective compression hardness of deformation to 10% of the initial thickness in the range of 20 to 1000 kPa, preferably in the range of 35 to 950 kPa, particularly preferably in the range of 45 to 900 kPa.

[0065] Particularly for use with the method disclosed below for dealing with a malfunction, it is preferred to keep the fluid guide channels as open as possible, which also enables particularly efficient cooling, wherein the volume fraction of fillers in the fluid guide channels is preferably less than 10%, preferably less than 5%, and most preferably less than 2%, based on the volume of the fluid guide channels.

[0066] To optimize the insulation and fire protection properties, the fluid channels can also be filled. This advantageously allows for the particularly efficient production of a high-performance hybrid material, which, according to the inventor, should be especially relevant for applications where particularly high thermal stress is expected. Against this background, a battery arrangement according to the invention is particularly preferred for demanding applications, wherein the separating element comprises at least one particulate filler, preferably an inorganic filler, and most preferably an inorganic porous filler, wherein the filler is arranged at least partially, preferably to a volume fraction of 50% or more, more preferably 70% or more, and most preferably 90% or more, in the fluid channels.A preferred battery arrangement according to the invention is wherein the filler is an inorganic filler, wherein the filler is preferably selected from the group consisting of inorganic silicon compounds, particularly preferably from the group consisting of precipitated silicon dioxide, pyrogenic silicon dioxide and silicate nanogel. A preferred additional or alternative battery arrangement according to the invention is wherein the combined mass fraction of fillers in the separating element is 15% or more, preferably 20% or more, particularly preferably 25% or more, based on the mass of the separating element.

[0067] By adding fillers to the fluid guide channels, the insulation properties can be advantageously adjusted in a targeted manner.

[0068] As described above, the inventor believes that in most cases it is preferable for the separating element to consist as largely as possible of the plastic structure, which offers advantages not only in terms of weight but also with regard to the permeability of the fluid channels. Accordingly, a battery arrangement according to the invention is preferred in which the separating element consists of the plastic structure to a mass fraction of 90% or more, preferably 95% or more, and particularly preferably 99% or more, based on the mass of the separating element.

[0069] Although this is less preferred from a manufacturing perspective in the inventor's opinion, the plastic structures in the separating element can potentially be combined with other layers with which further functionalities can potentially be realized, for example, with regard to their effect as a diffusion barrier or heat insulation. For certain applications, a battery arrangement according to the invention is preferred in this case, wherein the planar separating element comprises one or more further first functional layers, the first functional layer preferably being selected from the group consisting of plastic foams, in particular silicone foams, textile sheet structures, preferably textile sheet structures, in particular felt or nonwovens.

[0070] Furthermore, additional layers can be provided, which in particular offer additional flame protection and shield against radiant heat. A battery arrangement according to the invention is preferred in this case, wherein the planar separating element comprises one or more further second functional layers, the second functional layer being selected from the group consisting of inorganic films, preferably metal films and mineral films, which optionally include binders, preferably aluminum foil and layered silicate films, in particular alumina silicate film.

[0071] To further optimize the protective effect against heat radiation, the inventor also proposes to use a opaque agent in the separating element, for example in the plastic of the structural element or the film element, or to provide a opaque agent layer on the surface of the structural element or film element, with which the optical absorption and emission properties can be optimized.

[0072] From the particularly advantageous manufacturing process of the structural elements by tube extrusion, the inventor has identified a further particularly preferred variant for implementing the invention. The structural element obtained by tube extrusion can be used as a section of the tube as a circumferential structural element, which can be placed around the battery units of the battery assembly like a cuff, resulting in a closed enclosure. This embodiment is particularly suitable for cylindrical cells when using round tubes, whereas a rectangular tube enclosure is particularly efficient for prismatic cells. In this embodiment, a particularly high dimensional stability of the separating elements is advantageously achieved.Advantageously, it is sufficient to encase only a portion of the battery units accordingly, so that some of the battery units are separated by the encasement of adjacent battery units. Starting with the tubular structural elements, the inventor has transferred this concept to the film elements, which can also be designed as circumferential film elements, thereby obtaining a cuff-like separating element. In this context, a battery arrangement according to the invention is preferred, wherein the three-dimensional plastic structure is a circumferential plastic structure, preferably a tubular plastic structure arranged around at least one of the battery units, and preferably a tubular macroscopically structured structural element.

[0073] To further optimize dimensional stability, the inventor proposes that several circumferential three-dimensional plastic structures can be interconnected, for example by bonding. This advantageously allows for the creation of a particularly stable network, for example in a honeycomb structure, in which the battery units are especially well stabilized and additionally protected against mechanical stresses. A battery arrangement according to the invention is therefore preferred, comprising a plurality of interconnected circumferential plastic structures, preferably those bonded by a material-bonded connection.

[0074] The inventor considers it particularly advantageous, when using the corresponding plastic structures, especially unfilled plastic structures, to be able to efficiently flush them with a cooling and / or extinguishing fluid in the event of a malfunction in the battery assembly. This allows, in particular, the efficient cooling of the battery units, for example with compressed air, and / or extinguishing in the event of fires, especially with extinguishing fluids suitable for solvent fires, in particular extinguishing foams or carbon dioxide, preferably carbon dioxide. Preferably, the battery assembly is configured to trigger such a reaction in the event of a malfunction.A preferred battery arrangement according to the invention further comprises a fluid reservoir for receiving a cooling and / or extinguishing fluid and a fluid guidance system for guiding the cooling and / or extinguishing fluid from the fluid reservoir to the battery units of the battery arrangement, wherein the fluid guidance system preferably comprises a pump unit for conveying the cooling and / or extinguishing fluid from the fluid reservoir and / or wherein the cooling and / or extinguishing fluid is stored in the fluid reservoir under overpressure, wherein the fluid reservoir is particularly preferably a propellant gas-filled compressed air reservoir.

[0075] The extinguishing infrastructure, i.e. the fluid reservoir and the fluid guidance system, is preferably designed, according to the inventor, such that the battery units, preferably all battery units of the battery arrangement, can be flushed with the cooling and / or extinguishing fluid within 1 s or less, preferably within 0.5 s or less.

[0076] In this context, the inventor proposes that it is advantageous to also provide suitable devices in the battery assembly to detect a malfunction, for example, by registering a thermal runaway in one or more of the battery units. A preferred battery assembly according to the invention further comprises means for detecting a malfunction in the battery assembly, preferably a thermal runaway or a fire, and preferably a gas leak detection or temperature monitoring unit for monitoring the temperature of the battery units of the battery assembly.

[0077] Against this background, the invention also relates to a method for dealing with a malfunction in a preferred battery arrangement according to the invention, comprising the method steps: a) detecting a malfunction in the battery arrangement, in particular a thermal runaway or a fire or a gas leak, b) guiding a cooling and / or extinguishing fluid, in particular a cooling or extinguishing gas, especially air, from the fluid reservoir to the battery units of the battery arrangement, wherein the cooling and / or extinguishing fluid is introduced at least partially into the fluid guide channels.

[0078] Finally, in accordance with expert expectations, a vehicle comprising a battery arrangement according to the invention is also disclosed.

[0079] The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying figures. The figures show:

[0080] Fig. 1 shows a schematic cross-sectional view of a preferred battery arrangement according to the invention;

[0081] Fig. 2 schematic cross-sectional views through macroscopically structured structural elements for use in preferred battery arrangements according to the invention; and

[0082] Fig. 3 schematic cross-sectional views through foil elements for use in preferred battery arrangements according to the invention.

[0083] Fig. 1 shows a simplified schematic cross-sectional view of a preferred battery arrangement 10 according to the invention. In the example shown, two battery units 12a, 12b are electrically connected to each other, with battery management being carried out via a battery control unit 30, which is shown schematically in Fig. 1.

[0084] The battery arrangement 10 shown also includes a fluid reservoir 24 with a cooling or extinguishing fluid arranged inside, namely carbon dioxide, and a fluid guidance system 26 for guiding the cooling or extinguishing fluid from the fluid reservoir 26 to the battery units 12a, 12b. In addition, the battery arrangement has means for detecting a malfunction 28, for example, a thermal runaway or a fire in the battery units 12a, 12b.

[0085] In the example shown, the battery units 12a and 12b are lithium-ion battery cells designed as pouch cells. A separating element 14 is arranged between the battery units 12a and 12b, by which the two battery units 12a and 12b are completely separated from each other so that there is no direct contact between them.

[0086] Fig. 1 shows an example of a section that can be part of a larger battery arrangement 10, which can, for example, include further battery units 12a, 12b separated by separating elements 14 and arranged together in a battery housing.

[0087] In the example shown in Fig. 1, the separating element 14 comprises a plastic structure 16, which is designed as a macroscopically structured structural element and, in the example shown, is essentially made entirely of a thermoplastic silicone elastomer. The fluid guidance channels 18 formed thereby are filled in the example shown with a particulate, inorganic porous filler 22, namely silicate nanogel.

[0088] For better understanding, Fig. 1 also shows a view of the battery arrangement 10 from below. In this view, it can be clearly seen that the macroscopically structured structural element of the plastic structure 16 comprises a plurality of structural protrusions 20 arranged on the surface of the structural element, which contact the battery units 12a, 12b and are biased against them, with a connection between the battery units 12a, 12b and the macroscopically structured

[0089] The structural element is formed by a multitude of fluid guidance channels 18, which can be flooded with the extinguishing fluid from the fluid reservoir 26 in the event of a detected malfunction.

[0090] In the example shown, the structural protrusions 20 are arranged on both sides of the surface of the structural element and extend over the entire length of the structural element, with the structural protrusions 20 having a maximum height of about 1 mm relative to the surface of the structural element, resulting in a total thickness of about 3 mm for the structural element.

[0091] Figure 2 shows, in addition to the plastic structure 16 also used in Figure 1, two alternative preferred plastic structures 16. The middle plastic structure 16 largely corresponds to the plastic structure 16 discussed above, but has a different deformation behavior due to the alternating arrangement of the structural protrusions 20. In contrast, the third plastic structure 16 does not have structural protrusions 20, but achieves the macroscopic structuring through a kinked profile of the structural element, which has the shape of a periodic rectangular function. All of the structural elements shown in Figure 2 can be produced in a time- and cost-efficient manner by tube extrusion, which particularly allows for the achievement of low thicknesses. The extruded tube can be easily cut to obtain the structural elements.

[0092] Fig. 3 shows three different cross-sections through folded film elements, which can alternatively be used as plastic structures 16 in preferred battery arrangements 10 according to the invention. In each film element, a plastic film, for example made of PET, is formed into a shape that exhibits macroscopic elastic properties. The film elements shown have the cross-sectional shape of a periodic triangular, rectangular, or dovetail function.

[0093] Reference mark

[0094] 10 Battery arrangement

[0095] 12a-b battery units 14 separating element

[0096] 16 plastic structure

[0097] 18 Fluid guide channel

[0098] 20 Structural Survey

[0099] 22 Filler 24 Fluid reservoir

[0100] 26 Fluid guidance system

[0101] 28 means of recording an incident

[0102] 30 Battery control unit

Claims

Claims 1. Battery arrangement (10), in particular for use in electric vehicles and stationary applications, comprising two or more battery units (12a, 12b), wherein a separating element (14) is arranged at least between two adjacent battery units (12a, 12b), which separates the battery units (12a, 12b) from each other at least section by section, wherein the separating element (14) comprises or consists of an elastically deformable, three-dimensional plastic structure (16), wherein the three-dimensional plastic structure (16) is: i) a macroscopically structured structural element comprising or consisting of a thermoplastic elastomer, or ii) a corrugated and / or folded and / or bent film element comprising or consisting of a thermoplastic plastic, wherein the three-dimensional plastic structure (16) is designed such that a separation element exists between the three-dimensional plastic structure (16) and at least one of the battery units (12a, 12b).12b) a large number of fluid guidance channels (18) are formed.

2. Battery arrangement (10) according to claim 1, wherein the battery units (12a, 12b) are pouch cells or comprise pouch cells.

3. Battery arrangement (10) according to one of claims 1 or 2, wherein the three-dimensional plastic structure (16) comprises a macroscopically structured structural element comprising or consisting of a thermoplastic elastomer.

4. Battery arrangement (10) according to one of claims 1 to 3, wherein the thermoplastic elastomer is selected from the group consisting of thermoplastic silicone elastomers, thermoplastic polyamide copolymers, thermoplastic polyester copolymers, thermoplastic styrene copolymers, thermoplastic urethane copolymers, non-crosslinked thermoplastic poly-olefin blends, dynamically crosslinked thermoplastic poly-olefin blends and thermoplastic fluoroelastomers.

5. Battery arrangement (10) according to one of claims 1 to 4, wherein the macroscopically structured structural element is a corrugated and / or bent structural element.

6. Battery arrangement (10) according to one of claims 1 to 5, wherein the macroscopically structured structural element comprises a plurality of structural protrusions (20) arranged on the surface of the structural element.

7. Battery arrangement (10) according to one of claims 1 to 6, wherein the structural protrusions (20) are arranged on both sides of the surface of the structural element.

8. Battery arrangement (10) according to any one of claims 1 to 6, wherein the structural elevations (20) have a maximum height in the range of 0.2 to 6 mm relative to the surface of the structural element.

9. Battery arrangement (10) according to one of claims 1 or 2, wherein the three-dimensional plastic structure (16) is corrugated and / or folded and / or a folded foil element comprising or consisting of a thermoplastic material.

10. Battery arrangement (10) according to one of claims 1 to 9, wherein the foil element has the cross-sectional shape of a periodic function.

11. Battery arrangement (10) according to any one of claims 1 to 10, wherein the distance between adjacent maxima and minima of the corrugated and / or bent and / or folded foil element is in the range of 0.8 to 6 mm.

12. Battery arrangement (10) according to one of claims 1 to 11, wherein the three-dimensional plastic structure (16) is a circumferential plastic structure (16) which is arranged around at least one of the battery units (12a, 12b).

13. Battery arrangement (10) according to any one of claims 1 to 11, wherein the combined mass fraction of fillers (22) in the separating element (14) is 15% or more, based on the mass of the separating element (14).

14. Battery arrangement (10) according to one of claims 1 to 13, further comprising a fluid reservoir (24) for receiving a cooling and / or extinguishing fluid and a fluid guidance system (26) for guiding the cooling and / or extinguishing fluid from the fluid reservoir (24) to the battery units (12a, 12b) of the battery arrangement (10).

15. Battery arrangement (10) according to any one of claims 1 to 13, further comprising means for detecting a malfunction (28) in the battery arrangement (10).

16. Method for dealing with a malfunction in a battery arrangement (10) according to any one of claims 14 or 15, comprising the method steps: a) detecting a malfunction in the battery arrangement (10), b) supplying a cooling and / or extinguishing fluid from the fluid reservoir (24) to the battery units (12a, 12b) of the battery arrangement (10), wherein the cooling and / or extinguishing fluid is at least partially supplied to the Fluid guide channels (18) are introduced.

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