Multi-layer protection element for battery

Abstract

To propose a multi-layer protection element for thermal insulation of a battery, a battery with such a protection element, and a usage of the protection element to filter gases escaping in the event of fire and to prevent the escape of flames and / or sparks.SOLUTION: A highly gas-permeable protection element comprises a carrier layer of a fabric, and a compressible fiber layer in the form of a sewn non-woven fabric. The protection element is arranged between at least one battery cell and a housing wall of the battery, and covers an outlet of the housing wall on the inside. This enables good pressure compensation in the event of fire and / or a short circuit, where escaping gases are filtered in particular through the fiber layer and the escape of flames or sparks through the outlet is prevented.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a multilayer protective element, in particular for thermal insulation, of a battery according to the preamble of claim 1, to a battery with a multilayer protective element according to the preamble of claim 10, and to a method for using a multilayer protective element according to the preamble of claim 15. [Background technology]

[0002] In the present invention, the term "protective element" is preferably to be understood as a flat part having a layer structure, in particular a layer package, designed and / or used for the thermal insulation and / or any other shielding of a battery and / or its cells. In particular, the protective element is configured to reduce and / or delay the release of heat into the environment, in particular the vehicle passenger compartment, and / or to contain and / or reduce and / or delay the spread of heat in the battery in the event of uncontrolled and / or excessive heat development in the battery. In the present invention, the term "battery" is to be understood as meaning in particular a rechargeable storage element and / or secondary element for providing electrical energy by converting chemical energy. A battery preferably consists of several interconnected accumulator cells and / or cell blocks, i.e., battery cells. In particular, the battery is configured as a traction battery and / or for driving an electric vehicle and / or as a lithium-ion battery, where reliable and / or effective thermal insulation is important in order to protect the vehicle occupants in the event of battery overheating, for example as a result of a road accident, at least until the arrival of rescue services.

[0003] Due to their chemical composition, lithium-ion batteries in particular exhibit relatively high instability. If a local short circuit occurs in the electrodes due to contamination of the separator separating the internal electrodes in a battery cell, for example, due to trapped foreign particles and / or mechanical action or damage, a strong short-circuit current can quickly heat the battery cell to 800 °C, sometimes even 1300 °C. This process is known as thermal runaway. Because separators, in particular, lose stability at relatively low temperatures, e.g., above 120 °C, thermal runaway in one battery cell can easily and / or quickly spread to other adjacent battery cells, thus rapidly short-circuiting the adjacent battery cells. This can lead to an unstoppable chain reaction, in which the energy stored in the battery is quickly released, usually explosively and / or with the release of toxic gases and the formation of flames and / or sparks. There is also a risk of the battery exploding if the internal pressure increases accordingly.

[0004] WO 2019 / 121641 A1 discloses a multilayer protective element for a battery for thermal insulation. The protective element comprises a heat-resistant carrier layer and a heat-resistant, compressible fiber layer. To enable pressure equalization in the event of a fire and / or explosion, the battery housing has an outlet equipped with a filter or valve. It is therefore desirable to keep battery cells adjacent to a battery experiencing thermal runaway and / or overheating at a certain limiting temperature, preferably below 120° C., and especially below 80° C., for as long as possible. Above 80° C., the degradation process of the battery cells is significantly accelerated, and above 120° C., separators in the battery cells often begin to melt, with irreversible damage and / or short circuits. Similarly, there is a high demand for efficient and / or long-lasting thermal protection of adjacent areas and / or interior spaces, especially the vehicle cabin, against uncontrolled heat buildup in the battery. In particular, occupants and / or objects should be protected from the heat until rescue and / or recovery procedures are fully completed. Additionally, during rescue operations, rescuers should also be protected against uncontrolled explosion when the battery is under thermal runaway, and the risk of toxic gases (e.g., gaseous hydrofluoric acid), sparks, and flames escaping should be reduced. Summary of the Invention

[0005] The object of the present invention is to provide a multi-layer protective element, in particular for the thermal insulation of a battery, a battery having such a protective element, and a method for using the protective element, which allows good pressure compensation to prevent the battery from exploding in the event of fire and / or overheating or a short circuit with a simple, low-cost construction, while at the same time escaping gases are eliminated and / or the escape of flames and / or sparks is minimized or even prevented. The above object is achieved by a multilayer protective element according to claim 1, by a battery according to claim 10 or by a use according to claim 15. Advantageous embodiments are the subject of the subclaims.

[0006] A first aspect of the present invention is that the proposed protective element, at a pressure difference of at most 200 Pa and a thickness of at least 3 mm, has a gas permeability of more than 25 mm / s—at least in the event of a fire and / or a temperature exceeding 300°C. In the event of a fire and / or a short circuit or elevated temperature—particularly in the event of an accident—such a design allows optimal pressure compensation through the protective element, allowing leaking gas to be removed through the protective element or its fiber layer and / or flames and / or sparks occurring in the battery to be contained. In particular, the carrier layer, and therefore also the protective element, can withstand high mechanical loads and / or pressure differences that may occur in such cases. Additionally, the protective element can thermally insulate the battery and / or its battery cells, in particular to at least reduce or delay thermal runaway of the battery and / or its spread to nearby battery cells and / or thermal effects on the environment, such as the vehicle or passenger compartment.

[0007] According to a second, independently feasible aspect of the present invention, the proposed protective element preferably has a gas flow rate of at least 50 mm / s and a gas flow resistance of less than 100 Pa at a thickness of at least 3 mm—at least in the event of a fire and / or a temperature exceeding 300°C. In the event of a fire and / or a short circuit or elevated temperature—particularly in the event of an accident—such a design allows optimal pressure compensation through the protective element, allowing leaking gas to be removed through the protective element and / or its fiber layer and / or flames and / or sparks occurring in the battery to be contained. In particular, the carrier layer, and therefore the protective element, can withstand high mechanical loads and / or pressure differences that may occur in such cases. Additionally, the protective element can thermally insulate the battery and / or its battery cells, particularly to at least reduce or delay thermal runaway of the battery and / or its spread to nearby battery cells and / or thermal effects on the environment, such as the vehicle or passenger compartment.

[0008] According to a third aspect of the present invention, which can also be realized independently, the carrier layer is preferably connected or bonded to the fiber layer only partially or via a gas-permeable and / or thermolabile connecting layer. This allows optimal pressure compensation through the protective element in the event of a fire and / or a short circuit or high temperature—particularly in the event of an accident—so that leaking gas is removed through the protective element and / or its fiber layer and / or flames and / or sparks occurring in the battery are contained. In particular, the carrier layer, and therefore the protective element, can withstand high mechanical loads and / or pressure differences that may occur in such cases. In addition, the protective element can thermally insulate the battery and / or its battery cells, particularly to reduce or delay thermal runaway of the battery and / or its spread to nearby battery cells and / or the thermal effects on the environment, such as the vehicle or passenger compartment. According to a fourth, independently feasible aspect of the invention, the fibrous layer is preferably designed or provided as a non-woven fabric, in particular in the form of a needled fiber fleece and / or a knitted mat, and the fibrous layer, mat and / or ply are sewn together, which allows and / or achieves improved cohesion and / or simplifies processing, manufacturing, assembly and / or use.

[0009] It is particularly preferred that the fibrous layer be formed from long fibers greater than 30 mm in length and / or from needled and / or bonded nonwoven fabrics. The long fibers and / or needling and / or bonding of the fibrous layer significantly increase its mechanical resistance compared to other fibrous layers. As a result, the fibrous layer is particularly stretchable and pressure-resilient, allowing it to absorb high compressive forces. At the same time, the entangled fibers effectively reduce the passage of thermal energy through the fibrous layer, so the fibrous layer has high thermal insulation capacity. This is particularly advantageous in the event of uncontrolled heat generation within the battery, such as when thermal runaway occurs in a battery cell, as this significantly delays the complete destruction and / or explosion of the battery. Finally, needled nonwoven fabrics have a low mass per unit area, making them easy to handle.

[0010] Preferably, the fibrous layer is made from needled and / or bonded glass fibres or silicate fibres or mixtures thereof. Particularly preferably, the fibers of the fibrous layer have a length of at least 40 mm, preferably at least 50 mm, in particular essentially 50 mm to 60 mm, which allows the fibrous layer to have particularly high pressure and tear resistance. In particular, the fibres have an average diameter of at least 4 μm, preferably at least 5 μm, in particular between 6 μm and 15 μm. It is particularly preferred that the fibrous layer be binder-free and / or melt bead-free. Preferably, the fibrous layer and the intermediate material each have a density of 1800 g / m 2 less than 1300 g / m 2 Less than 600 g / m 2 Less than and / or 150g / m 2More than 200 g / m 2 Ultra, especially 300g / m 2 or 400g / m 2 It has a mass per unit area of ​​more than 10 ...

[0011] In particular, the mechanical stability of the protective element can be significantly increased and / or improved by using a fabric as the carrier layer, which is particularly advantageous as mechanical protection in the event of a battery cell explosion. Preferably, the protective element is designed to be highly gas-permeable and / or gas-permeable, in particular the carrier layer comprises or is formed by a fabric, so that explosive gases can be very easily dissipated through the carrier layer and the fabric layer, which can reduce the risk of explosion and / or rupture of the battery enclosed and / or surrounded by one or more protective elements. The protective element in particular has a dielectric strength of more than 20 kV / mm, preferably more than 30 kV / mm, in particular 40 kV / mm to 70 kV / mm, which avoids and / or delays the formation of arcs or sparks. In particular, the protective element—preferably when installed—has a thickness of less than 7 mm, preferably less than 6 mm, in particular between 2 mm and 3 mm, which allows a flexible and easy installation in the battery even in narrow installation gaps.

[0012] In particular, the protective element is provided with an adhesive layer on at least one flat side, in particular only partially covering it, or is designed to be adhesive at least in places on one flat side, which allows the protective element to be easily positioned and / or attached to or on the battery and / or further protective elements. Preferably, the protective element has a weight of 1800 g / m 2 less than 1300 g / m 2 Less than 1000g / m 2 Less than and / or 150g / m 2 More than 200 g / m 2 Ultra, especially 300g / m 2 or 400g / m 2It has a mass per unit area of ​​greater than 10 ... The thermal conductivity of the protective element at room temperature of 25° C. is less than 0.1 W / mK, preferably less than 0.08 W / mK, in particular less than 0.04 W / mK. The proposed battery, preferably a lithium-ion accumulator, in particular a lithium-ion accumulator in the form of a traction battery for electric vehicles, comprises a housing and at least one multilayer protective element arranged in and / or on the housing, in particular for thermal insulation and / or fire protection.

[0013] According to a fifth aspect of the invention, the protective element of the proposed battery is preferably designed according to one of the aforementioned aspects, which leads to advantages for the battery as explained above. According to a sixth aspect of the invention, which can also be realized independently, the protective element of the proposed battery is preferably arranged between the housing and at least one battery cell of the battery and covers the outlet in order to remove gases escaping through the housing outlet in the event of a fire and / or a short circuit and / or to minimize or even prevent the escape of flames and / or sparks through the outlet, which again results in the advantages already mentioned and also allows in particular a simple construction and / or assembly of the battery. Preferably, the protective element at least partially, preferably completely or entirely, closes and / or insulates the battery or battery cell or housing on the top and / or sides—outside or inside—which allows for effective thermal insulation of the battery toward the top and / or the area above and / or adjacent to the battery, in particular toward the vehicle interior. In this way, people, occupants and / or objects in the area and / or the interior are effectively and / or for a sufficiently long time—i.e., until rescue and / or recovery measures are completed—against uncontrolled heat buildup in the battery.

[0014] According to a seventh, independently feasible embodiment of the present invention, preferably some or all battery cells of a battery are enclosed / covered by the or each one of the protective elements, i.e., in particular individually enclosed / covered. It is particularly preferred that the protective element is adapted in shape to each battery cell. For example, sleeve-shaped protective elements can be provided for cylindrical battery cells. This provides very good thermal insulation in a simple and at the same time fairly gas-permeable design in case of fire and / or explosion and / or short circuit. For example, a protective element can be placed between two adjacent battery cells in the housing and thermally insulate them from each other, thus effectively slowing and / or inhibiting and / or even preventing the spread of thermal runaway from one battery cell to adjacent and / or nearby battery cells, thus preventing or at least significantly slowing the explosive release of heat and / or debris from the battery. It is particularly advantageous if, in the proposed battery, the protective element comprises at least one carrier layer of fabric.

[0015] According to an eighth aspect of the present invention, which can also be realized independently, a multilayer protective element, specifically designed according to one of the above aspects, is used for thermal insulation of a battery and / or for filtering gases leaking through an outlet of the battery in the event of a fire and / or a short circuit, and / or for preventing the escape of flames and / or sparks through the outlet. The protective element is disposed between the housing and at least one battery cell of the battery and covers the outlet on the inside. A very simple structure and assembly of the battery thus enables optimal pressure compensation through the protective element, allowing leaking gases to be removed through the protective element and / or its fiber layer and / or containing flames and / or sparks arising in the battery. In particular, the carrier layer, and therefore also the protective element, can withstand large mechanical loads and / or pressure differences, such as may occur in the event of an accident and / or a short circuit. In addition, the protective element can thermally insulate the battery and / or its battery cells, particularly to at least reduce or delay thermal runaway of the battery and / or its spread to nearby battery cells and / or environmental impacts, such as the vehicle or passenger compartment.

[0016] According to a ninth, independently feasible aspect of the present invention, the proposed protection element is most preferably used and / or arranged for insulation between one or more battery cells on the one hand and the control device and / or control electronics of the battery on the other hand, in particular the control device and / or control electronics within the battery housing. This can again result in optimized insulation and / or the fact that the battery remains stable for a longer period than usual even in the event of thermal runaway. The aspects and features of the invention, besides those mentioned above, arising from the claims and the following description, can essentially be realized independently of one another in any combination and / or order. Additional advantages, features, capabilities and aspects of the invention arise from the claims and the following description of preferred embodiments based on the drawings. [Brief explanation of the drawings]

[0017] [Figure 1A]1 is a schematic cross-sectional view of the proposed multilayer protective element. [Figure 1B] FIG. 1 is a schematic diagram of a carrier layer in the form of a fabric. [Figure 1C] 1 is a schematic diagram of possible bonding and / or adhesive layers. [Figure 2] 1 is a schematic cross-sectional view of the proposed battery with a protective element. [Figure 3] 1 is a schematic cross-sectional view of a vehicle with the proposed battery. DETAILED DESCRIPTION OF THE INVENTION

[0018] Figure 1A illustrates in a schematic, non-scale cross-sectional view the proposed multilayer protective element 1. The protective element 1 is used in particular for thermal insulation and / or shielding of the proposed battery 8, which is illustrated in a schematic, non-scale cross-sectional view in Figure 2. The battery 8 (accumulator) is in particular designed as a lithium-ion accumulator and / or intended for a vehicle 12, as shown in Figure 3. Most preferably, battery 8 serves as a drive or traction battery for vehicle 12, which is preferably designed as an electric car and / or electric vehicle. However, the protective element 1 and / or the present invention may also be applicable and / or usable in general for the protection of batteries, for example in the medical field, for battery-powered electrical appliances such as leaf blowers, hedge trimmers or brush cutters, and for the protection of persons who carry batteries on or near their bodies, for example in the military or for other purposes.

[0019] In the following, a preferred structure of the protective element 1 will be described in more detail. The protective element 1 comprises a carrier layer 2 and a textile ply or layer 3 . The layers 2 and 3 are preferably connected to one another, in particular adhesively bonded, in particular by means of a connecting or connecting layer 4 formed and / or arranged between them, which facilitates handling and installation and / or in particular assembly. The protective element 1 preferably, but merely optionally, comprises an additional carrier layer 5 on the flat side of the fibrous layer 3 facing away from the (first) carrier layer 2, as shown in Figure 1A. The additional carrier layer 5 can be designed to correspond to the (first) carrier layer 2, so that the descriptions and explanations for the first carrier layer 2 apply mutatis mutandis. However, the additional carrier layer 5 may also be designed differently and optionally further comprise corresponding capabilities or characteristics.

[0020] The additional carrier layer 5 is preferably firmly connected or adhesively bonded to the fiber layer 3, as shown in Figure 1A, in particular via an (additional) connecting and / or connecting layer 6. This connecting and / or connecting layer 6 may in particular be designed exactly the same as or similar to the (first) connecting and / or connecting layer 4, so that the following description and features correspond in particular in this regard. The connecting and / or connecting layers 4 and / or 6 can be designed as partial bonds 4A, as shown in particular in Fig. 1C. Most preferred is a net-like application or arrangement of bonding or connecting areas connecting the fiber layer 3 and the carrier layer 2 and / or 5. In this way, a partial and / or regular flat connection of the carrier layer 2 and / or 5 with the fiber layer 3 can be realized with high gas permeability, even if the carrier layer 2 and / or 3 is connected flat and / or flat-side to the fiber layer 3.

[0021] As an alternative or in addition to connections and / or adhesive bonds, thermolabile adhesives and / or thermolabile connections and / or connection foils can also be used to achieve high gas permeation performance at elevated temperatures, in particular at temperatures above 200°C, preferably above 250°C, most preferably above 300°C, as will be explained in more detail below. The carrier layers 2 and / or 5 and the textile layer 3 are in particular connected by adhesive bonding, however other joining techniques are also possible, such as stitching or welding. The protective element 1 and / or the carrier layer 2 or 5 are optionally provided with an adhesive layer 7, in particular an adhesive layer that is only partially or regularly applied, and / or is designed to be adhesive in order to facilitate and / or enable fastening and / or assembly of the protective element 1 to and / or into the battery 8 and / or its housing 9. The carrier layers 2 and / or 5 preferably comprise or are formed from a gas-permeable fabric 2A as shown diagrammatically in Figure 1B, which is beneficial for its high mechanical load-bearing capacity and allows for a compact design with low thickness.

[0022] The terms "fabric" / "woven fabric" particularly refer to a preferably flat product formed by a plurality of threads crossing each other, the threads being guided above and below the weft threads, particularly in a repeating sequence. The fabric 2A is preferably a glass fiber fabric, an aramid fabric, a carbon fiber fabric or a silicate fabric. It is also possible for the fabric 2A to be a mixed fabric and / or to comprise or consist in particular of a mixture of glass fibers, carbon fibers, aramid fibers and / or silicate fibers. Most preferred for connecting the fabric 2A forming the carrier layer 2 and / or 5 to the fibrous layer 3 is a gas permeable and / or gas-permeable adhesive, which allows gas to escape and / or pass through, but the fabric 2A and / or fibrous layer 3 forms a barrier to sparks or flames. Preferably, fabric 2A has high heat resistance, preferably up to temperatures of about or above 1150°C. The fabric 2A preferably has a minimum mesh size of 0.1 mm and / or a maximum mesh size of 0.4 mm, for example, the most preferred mesh sizes are about 0.114 mm, about 0.22 mm or about 0.315 mm. Fabric 2A preferably has an open screen area of ​​at least 10%, in particular at least 20%, more preferably at least 30% and / or at most 45%, in particular at most 50% or 60%.

[0023] The carrier layer 2 and / or 5 preferably forms the covering or outer layer of the textile layer 3 and / or the protective element 1 . Optionally, at least one of the carrier layers 2, 5 is designed as a heat-resistant metal layer or ply, preferably aluminum and / or aluminum foil, or as a mica layer, preferably a mica paper layer. The mica layer is preferably provided with or reinforced with a scrim and / or fabric 2A and / or reinforcing fibers, or vice versa, particularly preferably on the side facing towards or away from the fiber layer 3 or the adjacent battery cell 8A. In particular, the carrier layers 2 and / or 5 and / or their basic structure, such as a scrim or fabric 2A, may be provided with or combined with a heat-resistant and / or heat-insulating material, such as mica.

[0024] For example, one and / or the first carrier layer 2 is designed as a heat-resistant mica layer, preferably a mica paper layer, and the other and / or the second carrier layer 5 is designed as a metal layer, preferably an aluminum foil or a metal cloth. However, both cover layers 2, 3 can also be designed identically, in particular as a mica layer, preferably a mica paper layer. This allows for particularly high heat resistance. Preferably, at least one of the carrier layers 2 or 5 provides mechanical stability such that in the event of an explosion of the battery 8 no fragments can penetrate the protective element 1 . Most preferably, the protective element 1 has a high degree of gas permeability. In particular, the protective element 1 has a gas permeability—measured in particular in terms of flow velocity—of more than 25 mm / s at a differential pressure (pressure loss) of 200 Pa or at most 200 Pa and a thickness of 3 mm or at least 3 mm.

[0025] The preferred gas permeability of more than 25 mm / s does not have to be observed for the entire range of differential pressures up to 200 Pa; for example, a value of more than 25 mm / s is achieved at a pressure drop of 150 Pa, but not below that, and still be fulfilled. The same applies for a thickness range of at least 3 mm. The desired gas permeability is exhibited even if the protective element 1 exhibits a gas permeability of more than 25 mm / s at a thickness of, for example, 3.5 mm, but not above that. In particular, the protective element 1 preferably has a gas permeability of more than 25 mm / s at a differential pressure (pressure drop) of 200 Pa, and the protective element 1 has a thickness of 3 mm. Most preferably, the protective element 1 has a gas permeability in the uncompressed or delivered state and / or in the compressed or worn state of more than 25 mm / s, in particular more than 40 mm / s, at a differential pressure (pressure loss) of (approximately) 200 Pa, in particular regardless of its actual thickness. Preferably, the protective element 1 has a gas permeability of less than 500 mm / s, in particular less than 400 mm / s, most preferably less than 300 mm / s, at a differential pressure (pressure loss) of 200 Pa or less and regardless of thickness or at a thickness of 3 mm or more. The gas permeability is preferably measured at a (predetermined) measurement temperature of the air flow, the downstream side of which preferably has normal pressure.

[0026] The protective element 1 is preferably not compressed when measuring the gas permeability, but can alternatively be compressed at 25 kPa depending on the particular installation situation desired and / or in the thickness direction. The gas permeabilities mentioned are preferably achieved and / or measured at a measurement temperature of the air flow in the normal range of at least 20°C and at most 25°C. According to design variants, particularly those with a thermolabile connection and / or adhesive bond between the carrier layer 2 and / or 5 and the fiber layer 3, the gas permeability is determined at room temperature or in the normal range mentioned above. Prior to the measurement, the protective element 1 is exposed to a treatment temperature of at least 400°C or 300°C, preferably at least 250°C and most preferably at least 200°C, in particular for about 30 or 60 minutes. The gas permeability is then measured as described above at a preferred measurement temperature of 20°C to 25°C. Preferably and / or alternatively, in particular when the protective element 1 is not preheated beforehand to the above-mentioned treatment temperature but is directly exposed to and measured in hot air, for example at least 250°C, preferably at least 300°C and in particular at least 400°C, the gas permeability is measured and / or reached at the end of a measurement and / or flow time of at the latest 30 or 60 seconds.

[0027] Alternatively, the protective element 1 can first be preheated for measurement to a desired preheat temperature, for example 300°C, 400°C or 450°C, for a preheat time, for example 1 hour, and then the gas permeability can be measured at the desired measurement temperature or preheat temperature described. As an alternative to the above-described determination of gas permeability by measuring the flow rate through the protective element 1 at a given differential pressure, the gas permeability can also be determined by measuring the gas flow resistance (differential pressure or pressure drop) at a given flow rate, which gas flow resistance or pressure drop / drop acts inversely on the gas permeability or flow rate. Alternatively or additionally, the protective element 1 preferably has a gas flow resistance (pressure loss) of less than 100 Pa at a gas flow rate of 50 mm / s or at least 50 mm / s and a thickness of 3 mm or at least 3 mm. Alternatively or additionally, the protective element 1 preferably has a gas flow resistance (pressure loss) of less than 500 Pa at a gas flow rate (velocity) of 500 mm / s or at least 500 mm / s and a thickness of 3 mm or at least 3 mm. The measurement is realized as explained above, with the pressure loss / drop being determined here instead of the flow rate, and the flow rate being kept constant, in particular at a desired value. The other measurement conditions are similar, i.e. the measurement is carried out with air at the appropriate temperature and conditions.

[0028] The protective element 1 will exhibit the desired gas flow resistance of less than 100 Pa even if this value is achieved, for example, at a gas flow rate of 550 mm / s but not above that, and / or at a thickness of 3.2 mm but not above that. The protective element 1 preferably has a gas flow resistance (pressure loss) of more than 10 Pa at a gas flow rate of 50 mm / s and a thickness of 3 mm. Preferably, the protective element 1 consists of only two functional layers 2 and 3 or three functional layers 2, 3 and 5. In this context, the term "functional layer" must be understood as each layer providing a significant filtering function as the fiber layer 3 and / or a protective function (burst protection) as the carrier / fabric layer 2 in the event of an accident, runaway, explosion, etc. This does not exclude that the protective element 1 may additionally also comprise non-functional layers, such as connecting layers 4, 6 and / or adhesive layers 7, etc. The protective element 1 and / or layers 2 or 5 and 3 are preferably designed to be heat resistant, in particular to be heat resistant up to at least 200°C, most preferably above 250°C, 500°C or 1000°C, although the connection and / or adhesive bond of layers 4 / 6, carrier layer 2 and / or 5 to fiber layer 3 do not have to have this heat resistance.

[0029] The term "heat resistance" in the sense of the present invention is preferably used to describe the resistance or durability of a material or part to high or mentioned temperatures. In particular, the temperatures specified for the heat resistance represent preferred minimum values ​​of the melting temperature, or particularly preferred lower limits of 0.8 or 0.9 times the melting temperature, and / or preferred upper application temperatures in the sense explained below, and / or relate in particular to the substrate, e.g. in the case of the fibrous layer 3, in particular to its fibers, or in the case of the carrier layer 2, e.g. to its fabric 2A, each with or without a (fibrous) coating or sizing. A material or component, in particular the protective element 1 and / or one of the layers 2, 3, 5, is heat-resistant (up to an upper application temperature) in the sense of the present invention, in particular if up to this application temperature it is able to maintain its performance properties - for example its dielectric strength, its mechanical stability or shape, its strength or deformability, etc. - or does not change them to such an extent that they are no longer suitable for the desired application (in this case, sealing or insulating and / or electrical or thermal insulation of batteries or battery cells, in particular sealing or insulating and / or electrical or thermal insulation in the event of an accident or thermal runaway).

[0030] In particular, the carrier layer 2 or 5 should be considered as heat-resistant within the meaning of the present invention if it is made from or contains a fabric 2A of metal, mica or mica paper, or glass, silicate and / or ceramic microfibers or mixtures thereof. In particular, the fibrous layer 3 shall be considered as heat-resistant within the meaning of the present invention if it is made from or contains glass, silicate and / or ceramic fibres or mixtures thereof. Preferably, the material or component, in particular the protective element 1 and / or one of the layers 2, 3 or 5, is heat-resistant if it meets the requirements of one of the insulating material classes according to DIN EN 60085:2008-08, in particular insulating material classes F, H, N or R of this standard. The protective element 1 is particularly designed as a flat layer package and / or is designed to be particularly compressible and flexible.

[0031] The term "flexible" is preferably understood to mean a sufficiently low bending stiffness of the protective element 1, which is a measure of the resistance of the component and / or protective element 1 to bending deformation under applied forces. The bending stiffness is preferably determined in accordance with ISO 5628, preferably ISO 5628:2019. For this purpose, a plate-shaped protective element 1 having certain dimensions, for example, a thickness of 6 mm and dimensions of 60 mm x 40 mm, is clamped in a rotatable clamping device. The free end of the protective element 1 contacts a sensor of a load cell, via which the corresponding contact force is recorded as the clamping device is rotated. In particular, the sensor contacts the free end of the insulating element 1 at a distance of 50 mm from the clamping point. The bending stiffness is determined, in particular, by the force measured by the sensor when the protective element is bent by 15°. Preferably, the protective element 1 has a thus determined bending stiffness of less than 10N, preferably less than 5N, in particular less than 1N.

[0032] The proposed protective element 1 and / or the textile layer 3 are preferably compressible and thus allow adaptation to the installation conditions, in particular between the individual battery cells 8A and / or between the battery cells 8A and the housing 9. Most preferred is an installation with a certain initial load and / or compression of the protective element(s) 1 in the installed state. Preferred compression is at least 20 kPa and / or more than 25 kPa when installed. Some battery cells 8A expand and contract as a function of their state of charge. The protection element 1 is specifically designed so that such "breathing" of the battery cells 8A can be compensated for. In particular, the protective element 1 is designed to withstand a compressive pressure of at least 200 kPa, most preferably at least 250 kPa or more, which is beneficial for possible "breathing" and / or high load capability of the battery cell 8A in case of fire, short circuit, accident, etc.

[0033] The term "compressible" is preferably understood to mean a sufficiently low compression hardness of the protective element 1, the compression hardness representing the pressure required to compress the test specimen and / or the protective element 1 by 40% of its original thickness. The compression hardness is preferably determined in accordance with DIN EN ISO 3386, preferably ISO 3386-1:1986, using a plate-shaped insulating element 1 having a thickness of 5 mm and dimensions of 300 mm x 200 mm as the test specimen and an aluminum plate having a thickness of 20 mm and dimensions of 190 mm x 80 mm as the indenter. Preferably, the protective element 1 and / or the fibrous layer 3 have a compression hardness required as described above of less than 40 kPa, preferably less than 30 kPa, in particular less than 20 kPa. Preferably, the protective element 1 and / or the fibrous layer 3 are highly elastically compressible (in the thickness direction, i.e. perpendicular to the surface extension), most preferably at least in the range of 90% to 50% of their undeployed thickness.

[0034] The fibrous layer 3 is preferably formed from a needled and / or bonded fibrous fleece / nonwoven. For the purposes of the present invention, the term "needled nonwoven" is preferably to be understood as a fabric whose fibers are randomly intertwined and thereby bonded by dry needling and / or needling without a binder and / or a molten bead. The fibrous layer 3 is preferably formed from or provided with a nonwoven and / or needled and / or reinforced / bonded fibrous fleece / nonwoven and / or knitted mat. Preferably, the fibrous layer 3 is free of binders and / or melt beads.

[0035] As shown by yarn 3A in Figure 1A, a fibrous layer 3 and / or a fibrous fleece and / or a knitted mat and / or a nonwoven fabric are most preferred, which can improve the stability and / or processability of the fibrous layer 3 and / or the protective element 1. Any sutures are preferably relatively loose and / or placed over a relatively large distance of 1 millimeter or more. The stitching is preferably carried out before the application and / or lamination of the carrier layer 2, 5 or other covering layer, ie not particularly with other layers and / or only for its own stabilization. Most preferred is fiberglass stitching, ie, fiberglass thread 3A stitching. Tests have shown that very good stability and ideal performance can be achieved when nonwoven / fiber fleece and / or knitted fabrics are stitched with 3A threads made at least essentially of silicate fibers, most preferably glass fibers.

[0036] The textile layer 3 may have a multi-layer / multi-material design and may optionally be stitched and / or provided with intermediate layers and / or materials. The fibrous layer 3 is made in particular from glass or silicate fibres or mixtures thereof. For example, glass fibres, in particular from A, C, D, E, ECR, S2 or R glass or mixtures thereof, and / or other heat-resistant fibres may be used. The fibres preferably have an average diameter of at least 4 μm, in particular at least 5 μm, and most preferably essentially between 6 μm and 15 μm. The length of the fibres is preferably more than 30 mm, preferably more than 40 mm, in particular essentially 50 mm to 60 mm. In principle, however, the length of the fibres can also be greater, for example up to about 120 mm. Preferably, the mass per unit area of ​​the fiber layer 3 is 1800 g / m 2 or 1500g / m 2 less than 1300 g / m 2 Less than 600 g / m 2 Less than and / or 150g / m 2 More than 200 g / m 2 Ultra, especially 300g / m 2 or 400g / m 2 It's super. Preferably, the mass per unit area of ​​the protective element 1 is 1800 g / m 2 or 1500g / m 2 less than 1300 g / m2 Less than 1000g / m 2 Less than and / or 150g / m 2 More than 200 g / m 2 Ultra, especially 300g / m 2 or 400g / m 2 It's super.

[0037] The protective element 1 preferably has a thickness, especially in the uncompressed or delivery state, of less than 15 mm, preferably less than 10 mm, in particular between 3 and 8 mm. Particularly preferably, the protective element 1 has a dielectric strength of more than 20 kV / mm, preferably more than 30 kV / mm, in particular between 40 kV / mm and 70 kV / mm. Dielectric strength defines the limit of the electric field within a material without voltage breakthrough (electric arc or spark) occurring. The dielectric strength is preferably measured according to IEC 60243-1:2013. The measurements are preferably carried out under normal conditions between 20° C. and 25° C. and preferably at a relative humidity of about 50% and / or with the protective element 1 in its compressed state. In the following, the proposed battery 8 and the arrangement and / or use of the protective elements 1 according to the present proposal in the battery 8, in particular the protective elements 1A and 1B according to the present proposal and optionally further insulating elements 1C and 1D according to the present proposal or similar protective elements 1, will be explained in more detail based on Figure 2.

[0038] The protection elements 1A to 1D can be designed identically or differently. Hereinafter, the protection elements 1A to 1D will also be referred to as the first protection element 1A, the second protection element 1B, the third protection element 1C, and the fourth protection element 1D for the sake of distinction. However, this serves only to distinguish between different protection elements 1, and does not mean that, for example, when the third protection element 1C is provided, the second protection element 1B must also be present. Preferably, a battery 8 is disposed and / or installed in the schematically represented vehicle 12, particularly an electric vehicle, for power supply purposes. In particular, when installed, the battery 8 is located in the passenger compartment 12A, e.g., below a passenger or other interior area of ​​the vehicle 12. The battery 8 preferably comprises a housing 9 having a top housing portion and / or housing lid 9A and a housing bottom, wherein the housing 9 and / or housing bottom comprises at least one housing sidewall 9B and a housing bottom 9C. The housing 9 preferably consists of a non-conductive material, for example plastic, or of metal.

[0039] The battery 8 is preferably designed as a rechargeable accumulator, in particular a lithium-ion accumulator, alternatively it can be constructed or designed with lithium iron phosphate, lithium cobalt oxide, lithium metal oxide, lithium ion polymer, nickel zinc, nickel metal, nickel cadmium, nickel metal hydride, nickel silver, nickel metal hybrid, all-solid-state, lithium air, lithium sulfur and similar systems and / or materials. In particular, the battery 8 comprises at least one group of battery cells 8A, in particular electrically wired and / or housed in a housing 9, preferably in a lower housing part 10. Preferably, the protection element 1 is arranged within the interior space of a housing 9 that accommodates the battery cell 8A. It is preferred that at least one protective element 1, in particular a first protective element 1A, is preferably attached and / or fixed above the battery cell 8A and / or in particular to the housing 9 and / or housing lid 9A, preferably adhesively bonded thereto, in particular by means of an adhesive layer 7. The first protective element 1A closes and / or insulates the housing bottom and / or the battery 8 or its cells 8A, preferably on the upper side.

[0040] In this way, particularly efficient upper thermal insulation and fire protection for the passenger compartment 12A is achieved in order to protect people or objects inside efficiently and / or for a long enough time from uncontrolled heat development in the battery 8. The battery 8 and / or the housing 9 preferably comprise at least one outlet 10, which allows - at least in the event of fire and / or excessive heating or strong pressure buildup inside the battery 8 - gas to escape from the battery 8 and / or the housing 9 to the outside and thus pressure compensation. This prevents the battery 8 from exploding and / or rupturing, especially in the event of fire and / or short circuit and / or overheating. The outlet 10 is preferably located on the housing lid 9A and / or on the upper side of the battery 8 and / or housing 9. The cell 8 and / or the housing 9 preferably comprise several outlets 10 for gas escape and / or pressure compensation. Preferably, the and / or each outlet 10 is essentially and / or at the time of delivery and / or during normal use or as long as necessary closed or closable, in particular by means of a thermally unstable and / or non-pressure stable element 11, most preferably by means of a bursting disc or the like.

[0041] Instead of a rupture disc, for example, a further element or valve can also be used as closure element 11, which essentially seals off outlet 10 and opens in the event of a fire and / or in the event of a short circuit or overheating - preferably opening automatically as a function of pressure and / or temperature. However, other design solutions are also possible.

[0042] In the event of a fire, short circuit, overheating, or other pressure increase in the housing 9, pressure compensation can be achieved via the outlet 10 by allowing gas to flow out of the housing 9 through the outlet 10, particularly after the opening of a rupture disk and / or valve. The protective element 1 and / or its fiber layer 3 act as a filter, thereby removing and / or retaining unwanted toxins and gases. Furthermore, the protective element 1 acts as a barrier against the escape of flames or sparks through the open outlet 10. In addition, the at least one carrier layer 2 can bear mechanical loads that may suddenly occur when the outlet 10 is suddenly opened and / or the battery is in thermal runaway, so that the protective element 1 retains its desired filtering and safety functions against the escape of flames, particularly in the above-mentioned cases where gas flows out through the outlet 10. This load-bearing ability of the protective element 1 is supported by the preferably intended high gas permeability and the advantageous design of the at least one separating layer 2, particularly as fabric 2A. In the example, the housing 9 comprises one or more outlets 10, in particular in the housing lid 9A, which are preferably lined on the inside by the protective element 1 and / or the first protective element 1A.

[0043] Alternatively or additionally, the battery 8 and / or the housing 9 and / or at least one housing side wall 9B may also be provided with one or more side outlets 10, as illustrated in Figure 2. In this case, in particular in addition to or as an alternative to the first protective element 1A, a further and / or second protective element 1B is also provided, covering the respective side wall 9B and / or the respective side outlet 10. In particular, at least one first protective element 1A and at least one second protective element 1B are used, the first protective element 1A sealing and / or thermally insulating the interior of the housing on the upper side, and the second protective element 1B being arranged laterally on the housing side wall 9B. Preferably, the second protective element 1B is attached to the first protective element 1A, in particular transversely and / or perpendicularly, preferably adhesively bonded, sewn or welded. Preferably, all side walls 9B of the battery 8 and / or housing 9, preferably also independently of the outlets 10 formed, are provided on the inside with or covered by the second protective element 1B.

[0044] The second protective element 1B is also preferably fastened and / or adhesively bonded to the associated side wall 9B, in particular by means of an adhesive layer 7 and / or a self-adhesive version of the respective protective element 1B. However, other construction solutions are also possible. The preferred proposed arrangement and inner coating of one or more outlets 10 with one or more protective elements 1 allows for very easy assembly and construction of the battery 8 and provides the desired pressure compensation in the event of fire and / or short circuit or overheating, while ensuring the desired filtering and protection performance at the outlets 10 for use in a vehicle 12. As an alternative or in addition to the first and / or second protective elements 1A and 1B, the battery 8 may comprise a further and / or third protective element 1C, as illustrated by way of example in FIG. 2. The third protective element 1C is preferably arranged opposite the first protective element 1A and / or on the underside and / or bottom 9C of the inside of the housing. Preferably, the underside and / or bottom 9C is completely and / or completely covered by the third protective element 1C. The third protective element 1C is preferably fastened and / or adhesively bonded to the sole 9C by means of an adhesive layer 7 and / or a self-adhesive design. However, other construction solutions are also possible.

[0045] The protection elements 1A to 1C are preferably each arranged on one battery cell 8A and / or between the battery cell 8A and the housing 9. Preferably, in the battery 8 and / or housing 9, the carrier layer 2 and / or fabric 2A is arranged inside the protective element 1 and / or protective elements 1A-1C facing the battery cell 8A. Alternatively or in addition to the protection elements 1A-1C, preferably at least one (further and / or fourth) protection element 1D is provided and arranged between the battery cells 8A, thereby thermally insulating and / or isolating them from each other. The protection element 1D is most preferably inserted, press-fitted, or provided in any other way between the battery cells 8A. The battery cell 8A is preferably at least substantially completely and / or on all sides enclosed by one or more 1D protective elements. The protective element 1 preferably also compensates for any possible expansion of the cells during charging and / or ensures a defined initial mechanical load as far as possible over the operational life of the battery 8. In delivery conditions, a pressure of at least about 25 kPa is required. Over the operational life, the pressure in installed conditions can increase to up to 250 kPa due to expansion (swelling) of the cells 8A. These values ​​vary depending on the cell type (circular cells, pouch cells and prismatic cells) and can be adapted to customer requirements.

[0046] In particular, the protective element 1D encloses and / or encapsulates some or all of the battery cells 8A such that they are supported and / or arranged in the housing 9 such that they are insulated, shielded and / or damped on all sides and / or in particular with respect to one another. The protective element 1 thus preferably forms a storage mat for the battery cells 8A. In addition to effective thermal insulation in particular on all sides, this also allows for a robust and / or resistant storage of the battery cells 8A, since any shocks and / or vibrations are damped and / or absorbed by the compressible protective element 1. The battery cells 8A are preferably - in groups or individually - at least substantially completely and / or on all sides enclosed and / or surrounded by one or more protective elements 1A-1D, i.e. insulated and / or shielded from each other in the battery 8. In the case of a cylindrical design of the battery cells 8A, the fourth protective element 1D can, for example, be designed as a hollow cylinder and can thus radially surround the battery cells 8A - in particular individually - and further protective elements 1, such as the first protective element 1A and the third protective element 1C, can, for example, axially cover or seal the battery cells 8A. In the case of a cell stack, an intermediate layer can also be formed for axial separation of the battery cells 8A from the protective element 1.

[0047] It should be noted that the protective elements 1 and / or 1D, in principle and in particular when arranged between the battery cells 8A - i.e. not arranged on the outside between the battery cells 8A and the housing 9 - can also be provided with additional layers, such as further fiber layers and / or, if necessary, further intermediate layers, separating layers or insulating layers, and can therefore also have a lower gas permeability. Tests have shown that the proposed protective element 1 is suitable both for thermal suppression within the battery 8 and for top and / or side placement and / or insulation, i.e., for thermal protection in particular of the adjacent compartment 12A.

[0048] Alternatively or additionally, the proposed protection element 1 can also be used and / or arranged, in particular in the housing 9 of the battery 8, to insulate the control, control device and / or control electronics 8B of the battery 8, in particular from one or more battery cells 8A, as is shown schematically on the right hand side of Figure 2, where for example the control device 8B may be placed in place of one cell 8A in the battery 8 and / or housing 9. This use or arrangement can also serve to contain heat and / or provide insulation within the battery 8, for example in case of failure and / or thermal runaway of a battery cell 8A, and thus ultimately stabilize the battery 8, in particular for a longer period of time than before. The individual aspects of the invention, as already mentioned, can be combined as desired, but can also be realized independently of one another. [Explanation of symbols]

[0049] 1(A, B, C, D) Protection elements 2. Carrier layer 2A Woven / Cloth 3 fiber layers 3A Thread 4. Connectivity Layer 4A Partial join 5 additional carrier layers 6 Connectivity Layer 7 Adhesive layer 8 batteries 8A battery cell 8B Control Unit / Control Device 9. Housing 9A Housing lid 9B Housing side wall 9C Housing bottom 10 exit 11 (Closure) Elements 12 vehicles 12A cabin

Claims

1. a heat-resistant carrier layer (2), preferably a carrier layer resistant to temperatures above 250°C, and a fibrous layer (3), preferably a compressible and / or fibrous layer resistant to temperatures above 250°C; A multilayer protective element (1) for a battery (8), comprising: said protective element (1) having a gas permeability of more than 25 mm / s at a pressure difference of 200 Pa or at most 200 Pa and a thickness of 3 mm or at least 3 mm—at least in the event of fire and / or when a temperature of 300° C. is exceeded; and / or and / or that the protective element (1) has a gas flow resistance of less than 100 Pa at a gas flow rate of 50 mm / s or at least 50 mm / s and a thickness of 3 mm or at least 3 mm—at least in the event of fire and / or when a temperature of 300° C. is exceeded. the carrier layer (2) is connected or adhesively bonded to the fiber layer (3) only partially or via a gas-permeable and / or thermolabile connecting or connecting layer (4), and / or The fiber layer (3) comprises a stitched nonwoven layer, in particular a needle fiber fleece and / or a knitted mat and / or a stitched nonwoven layer as a nonwoven fabric. Featuring multi-layer protection elements.

2. 2. A protective element according to claim 1, characterized in that the carrier layer (2) is or comprises a gas-permeable fabric (2A).

3. 3. A protective element according to claim 1 or 2, characterized in that the fibrous layer (3) is made from glass fibres or silicate fibres or a mixture thereof.

4. 4. A protective element according to any one of claims 1 to 3, characterized in that the textile layer (3) is or comprises a needled fibre fleece.

5. A protective element according to any one of claims 1 to 4, characterized in that the protective element (1) as a whole is compressible and flexible.

6. 6. A protective element according to any one of claims 1 to 5, characterized in that the protective element (1) has, on at least one flat side, an adhesive layer (7) that is at least in places sticky, or in particular only partially covering.

7. 7. Protective element according to any one of claims 1 to 6, characterized in that the protective element (1) consists of two functional layers: the carrier layer (2) as burst protection and the textile layer (3) for removal.

8. 7. A protective element according to any one of claims 1 to 6, characterized in that the protective element (1) consists of three functional layers, namely two carrier layers (2, 5) as burst protection and the textile layer (3) for removal.

9. A protective element according to any one of claims 1 to 8, characterized in that the textile layer (3) is stitched with glass fibre threads (3A).

10. It has a housing (9) and at least one multilayer protection element (1) arranged in said housing (9), in particular for thermal insulation and / or fire protection, the protective element (1) comprises a carrier layer (2), preferably a carrier layer resistant to temperatures above 250°C, and a fibrous layer (3), preferably a compressible and / or resistant to temperatures above 250°C; In a battery (8), preferably a lithium ion battery, in particular a traction battery for an electric vehicle (12), that the protective element (1) is designed according to any one of claims 1 to 9; and / or the protective element (1) is arranged between the housing (9) and at least one battery cell (8A) of the battery (8) and covers an outlet (10) of the housing (9) to remove gases escaping through said outlet (10) in the event of a fire and / or in the event of a short circuit or overheating, and / or to minimize or prevent the escape of flames and / or sparks through said outlet (10); and / or Some or all of the battery cells (8A) of the battery (8) are individually covered by the or each one of the protective elements (1). A battery.

11. 11. Battery according to claim 10, characterized in that the protective element (1) is arranged and / or fastened, preferably adhesively connected, to a housing lid (9A) of the housing (9) and / or to a housing side wall (9B) of the housing (9).

12. 12. Battery according to claim 10 or 11, characterized in that the outlet (10) is closed in the state of use by a thermally unstable and / or pressure-non-stable element (11), in particular a rupture disc, so that the outlet (10) can be opened - in particular automatically - by pressure and / or heat exposure.

13. 12. Battery according to claim 10 or 11, characterized in that the outlet (10) is closed by a valve and can be opened in the event of fire and / or in the event of a short circuit - preferably automatically as a function of pressure and / or temperature.

14. 14. The battery according to any one of claims 10 to 13, characterized in that the protective element (1) or an additional protective element (1D) having a compressible fiber layer (3) for thermal insulation is arranged between two adjacent battery cells (8A) of the battery (8).

15. Use of a multilayer protective element (1), in particular a multilayer protective element designed according to any one of claims 1 to 9, for the thermal insulation of a battery (8), having a carrier layer (2), preferably a carrier layer resistant to temperatures above 250°C, and a fibrous layer (3), preferably a compressible and / or resistant to temperatures above 250°C, the protective element (1) is arranged between the housing (9) and at least one battery cell (8A) of the battery (8) so that it lines the outlet (10) of the housing (9) to remove gases escaping through the outlet (10) in case of fire and / or in case of short circuit and / or overheating and / or to prevent flames and / or sparks from escaping through the outlet (10); and / or The protection element (1) is arranged between the battery cell (8A) of the battery (8) and the control and / or control device (8B) of the battery (8), in particular in the housing (9) of the battery (8) and / or is assigned to the control and / or control device (8B) of the battery (8) for insulation purposes. Characteristic, usage.

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