Cover plate for fire fighting and battery for a motor vehicle

Abstract

The invention relates to a cover plate (12) for fire fighting for arrangement above an electrical component and / or above at least one battery cell (16) of a battery (10), wherein the cover plate (12) comprises at least an outer layer (22), a cover layer (24) and an intermediate layer (26) arranged between the outer layer (22) and the cover layer (24).The intermediate layer (26) comprises a solid extinguishing agent (34) comprising numerous solid particles (36), and at least the outer layer (22) is made of a material that is destructible under a certain heat exposure, so that in the case of the certain heat exposure on the outer layer (22) in an area of ​​effect (40) of the outer layer (22) it is destroyed at least locally in the area of ​​effect (40) of the heat exposure by forming an opening (42), wherein the intermediate layer (26) is designed such that at least a part (26a) of the solid extinguishing agent (34) escapes from the opening (42) of the outer layer (22) formed by the certain heat exposure under the influence of gravity.

Description

[0001] The invention relates to a cover plate for fire suppression and for arrangement above an electrical component or above at least one battery cell of a battery, wherein the cover plate comprises at least an outer layer, a cover layer, and an intermediate layer arranged between the outer layer and the cover layer. The invention further relates to a battery for a motor vehicle.

[0002] Housing components for electrical components, especially for high-voltage batteries in motor vehicles, should ideally fulfill various functions or possess specific properties, such as being as lightweight as possible, exhibiting good fire resistance, being simple and inexpensive to manufacture, and possessing electromagnetic shielding properties, i.e., good EMC (electromagnetic compatibility) properties, or similar characteristics. Particularly in the context of high-voltage batteries, good fire protection properties are highly desirable. These are often achieved by coating the relevant components, especially the battery housing components, with fire-resistant layers or similar materials.

[0003] DE 10 2020 107 675 A1 describes a cover structure comprising an SMC (Sheet-Mould-Compound) base body pressed with a fire-retardant coating in an SMC tool. The cover structure may include an EMC layer bonded to the SMC base body. The EMC layer may be located on the large surface of the SMC base body facing away from the fire-retardant coating.

[0004] Furthermore, DE 10 2016 203 553 A1 describes a battery assembly with a battery housing comprising a tray-shaped battery carrier made of plastic or fiber-reinforced plastic with a base and a wall. The battery base is integrally formed with metallic inserts that, on the one hand, provide EMC protection and, on the other hand, are electrically connected to an earthing system.

[0005] Furthermore, a housing component with a multi-layered structure made up of different layers is also known from DE 10 2022 001 079 A1.

[0006] WO 2019 / 224 013 A1 describes a composite component for a vehicle, comprising a preformed component which has a reinforcing layer, at least in some areas of its surface, that adheres to the preformed component and comprises a particle foam. The particle foam allows for the simple reinforcement of preformed components.

[0007] If a battery cell experiences thermal runaway, it can result in a fire that can spread to neighboring cells. Similarly, the burning out of one cell can lead to the burning out of adjacent cells, resulting in a so-called "thermal runaway." In other components, such as electrical components, a fire can also ignite the surrounding area, potentially leading to the complete destruction of the component or even the entire battery, at least without countermeasures. While coating housing components, such as the battery cover, with a fire-resistant layer can delay the process and provide some shielding, it ultimately cannot prevent the burning out.

[0008] The object of the present invention is therefore to provide a cover plate and a battery that enable active fire suppression.

[0009] This problem is solved by a cover plate and a battery with the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0010] A cover plate according to the invention for fire suppression and for arrangement above an electrical component or above at least one battery cell of a battery comprises at least an outer layer, a cover layer, and an intermediate layer arranged between the outer layer and the cover layer. The intermediate layer comprises a solid extinguishing agent comprising numerous solid particles, wherein at least the outer layer is formed from a material that is destructible under a specific heat exposure, such that, in the event of the specific heat exposure to the outer layer, it is destroyed at least locally in the area of ​​effect of the heat exposure, forming an opening, and wherein the intermediate layer is designed such that at least a portion of the solid extinguishing agent escapes from the opening in the outer layer formed by the specific heat exposure under the influence of gravity.

[0011] The solid extinguishing agent, with its numerous solid particles, for example in the form of granules or powder, can thus be advantageously used to smother a fire caused by heat exposure to the outer layer. The cover plate can therefore be easily placed over the component to be protected, for example a battery cell or battery module, or any other electrical component requiring protection. If this component catches fire, the resulting heat exposure to the outer layer causes it to be destroyed, at least locally, and optionally globally, for example by melting. This creates an opening through which the extinguishing agent, namely the numerous solid particles, can then escape, covering the burning component underneath and thus smothering the fire.Therefore, the cover plate can advantageously not only achieve a fire-retardant effect, but also enable active fire fighting, even the extinguishing of a fire that has already started.

[0012] It is particularly advantageous if the cover plate is used as part of a battery, for example, as a battery cover or attached to such a cover. Specifically, the cover plate can be positioned over one or more battery cells of such a battery, for example, a high-voltage battery. Nevertheless, the cover plate can also be used in the same way for other electrical components and placed in a corresponding component housing or as part of such a housing, e.g., as a housing cover, above an electrical component requiring protection.

[0013] The term "above" can refer, for example, to a direction of gravity. With regard to a standard installation position in a motor vehicle in which the cover plate can be used, the cover plate can be positioned above the electrical component to be protected, or at least one battery cell, relative to the vehicle's vertical direction.

[0014] The solid extinguishing agent can be formulated such that there is no direct chemical bond between the numerous solid particles. Optionally, these particles can be indirectly bonded via a binder. They can also be present as loose bulk material and / or as a mixture of solid particles.

[0015] According to a particularly advantageous embodiment of the invention, the solid extinguishing agent comprises extinguishing granules and / or extinguishing powder and / or extinguishing earth. Granules and powders are understood to be numerous small particles, which may be, for example, unshaped or have an arbitrary or random geometry, or which may have a specific geometry, such as spherical shape. Examples of such granules or powders include sand, expanded glass beads, or similar materials. Earth, such as clay, can also be used as such a solid extinguishing agent. Further examples will be explained in more detail later. An extinguishing agent comprising such extinguishing granules or powders makes it possible to cover a burning component to be extinguished as airtight as possible in a particularly effective manner.In the event of a fire, the extinguishing agent can thus perform an extinguishing function by preventing the oxygen supply. Using granules, powder, or earth, a fire-smothering effect can be achieved particularly easily. Furthermore, it is preferable that the solid extinguishing agent be made of a non-combustible material. The solid extinguishing agent itself is therefore not combustible.

[0016] The cover plate can be a rigid or flexible component. In particular, the cover plate is designed as a large-area component. This makes it possible to cover a larger component requiring protection, for example, a battery module with multiple battery cells or even all battery modules, each containing multiple battery cells, within a high-voltage battery. The outer layer borders the surrounding environment of the cover plate. When the cover plate is used as intended, the outer layer faces the component to be protected, for example, the battery cell. In this way, an opening can be easily achieved by at least locally damaging the outer layer in the event of a fire, due to the resulting heat exposure.

[0017] The outer layer is in direct contact with the intermediate layer. There should be no other layer between the outer layer and the intermediate layer. This allows the intermediate layer, or at least a portion of it, to reliably escape if a corresponding opening forms in the outer layer due to heat.

[0018] If a certain amount of heat, which may be characterized, for example, by a specific minimum temperature in the area of ​​effect (e.g., greater than 100 °C or greater than 200 °C, and in particular at least 300 °C), acts on the area of ​​effect of the outer layer, the outer layer may only be damaged locally in this area of ​​effect, for example, by tearing, melting, burning, or similar causes. However, it is also possible that such localized heat exposure to the outer layer will damage a larger area of ​​the outer layer around the point of effect and / or even the entire outer layer. A localized opening in the outer layer is sufficient to extinguish the underlying component to be protected by smothering it with the solid extinguishing agent.On the other hand, opening only locally is also very advantageous in order to provide a particularly effective extinguishing function, since, for example, by locally opening the outer layer in the area of ​​effect, a kind of funnel function can be provided by the destroyed outer layer sections, which are still attached to or arranged on the intact outer layer sections, via which the extinguishing granules or powder, or in general the extinguishing agent, can be directed in a targeted manner onto the component to be extinguished underneath.

[0019] For example, if a battery or several battery cells catch fire over a larger area, the fire in these individual battery cells leads to several local heat impacts on the outer layer, for example in individual areas of impact or in a larger, continuous area of ​​impact, so that in this case several separate openings in the outer layer form and / or a larger continuous opening through which the respective burning components or battery cells can be efficiently extinguished by the solid extinguishing agent.

[0020] The material of the solid particles, e.g., the extinguishing granules and / or powder, can be such that it has a significantly higher melting point than the temperature associated with the specific heat exposure. In other words, the solid particles are designed so that they are not destroyed by the specific heat exposure, i.e., they do not melt, burn, dissolve, or anything similar. They retain their solid particle structure. Furthermore, the extinguishing granules or powder should be made of a non-combustible material. Suitable materials include, for example, glass, alumina, ceramics, expanded glass, steel, or similar materials.

[0021] According to a further advantageous embodiment of the invention, at least the outer layer is made of a thermoplastic material and / or is designed as a plastic film and / or a composite plastic film. Such a plastic film or composite plastic film can also be made of a thermoplastic material or at least comprise one. This design of the outer layer makes it easily and reliably at least locally destructible, in particular meltable, under the influence of heat. This enables a particularly reliable release of the opening under the influence of heat, and thus also of the solid extinguishing agent for extinguishing the flames or the fire.

[0022] According to a further advantageous embodiment of the invention, the outer layer and the top layer are formed as part of a shell enclosing an interior space, with the intermediate layer arranged within this interior space. The outer layer and the top layer need not be separate layers. For example, the shell, which then provides the outer layer and the top layer, can be a plastic or film shell. In addition to the outer layer and the top layer, such a shell can also include side elements or side walls connecting the outer layer and the top layer. The shell itself can be flexible and / or rigid, for example, partially flexible and partially rigid.For example, the outer layer, if designed as a film, can exhibit greater flexibility than the top layer, which, for instance, can be more rigid or less flexible than the outer layer due to its thicker construction. The entire casing can also be designed as a rigid or dimensionally stable housing. Even in this case, the outer layer can be made thinner than the top layer or the rest of the casing to allow for easy opening under heat. Furthermore, the outer layer and the top layer can be made of the same material or of different materials. As described above, at least the outer layer is preferably made of a plastic, particularly a thermoplastic. Using the same material simplifies the manufacturing of the casing.

[0023] The outer layer can also be made of a metallic material. For example, the outer layer can be designed as a thin metal foil. The material, especially a metallic one, can be chosen so that it melts at approximately 300 °C to 700 °C. For example, aluminum can be used as the material. However, other metals or alloys with a melting point in the range between 300 °C and 700 °C are also possible. The predetermined heat application can be defined such that a temperature of at least 300 °C is reached.

[0024] The intermediate layer can be positioned within the interior in such a way that it essentially or completely fills the space. This allows for particularly efficient use of installation space. If the shell is flexible, for example, designed as a foil shell, the intermediate layer can first be introduced into the interior of the shell during the manufacturing of the cover plate, for example, through a filling opening, an open edge, or similar. The interior of the shell can then optionally be vacuum-sealed, i.e., a vacuum created, e.g., by extracting air, and subsequently sealed. If the shell is partially rigid or stiff and / or dimensionally stable, vacuum-sealing the interior is not necessarily required.The intermediate layer can also be introduced into the interior space in such a way as to adapt to its volume and / or geometry, so that the space is completely or almost completely filled by the intermediate layer. This is particularly easy if the intermediate layer is in the form of granules, powder, or similar material.

[0025] Therefore, it is a further highly advantageous embodiment of the invention if the intermediate layer consists of extinguishing granules and / or extinguishing powder and / or extinguishing earth. The intermediate layer can also comprise a combination of extinguishing granules and / or extinguishing powder and / or extinguishing earth. However, the intermediate layer should generally consist of numerous individual particles. In this case, the intermediate layer should not be designed as a continuous solid. The solid particles of the intermediate layer exist without direct or indirect chemical bonds to one another and are mobile relative to each other. This allows for the particularly easy release of at least a portion of the intermediate layer through the opening created in the outer layer by the application of heat, and thus enables the fire to be extinguished by means of the granules, powder, or earth.Due to the relative mobility of the particles to each other, the part of the intermediate layer that has emerged through the opening can optimally adapt to the geometry of the component to be protected, whose fire caused the opening, and cover the burning parts of this component particularly efficiently in order to cut off the oxygen supply and smother the fire.

[0026] According to a further advantageous embodiment of the invention, the intermediate layer comprises a coherent solid body comprising a solid substance that melts at least locally under the influence of a specific heat. This solid substance constitutes a binder and / or a material matrix into which the solid extinguishing agent, in particular the extinguishing granules and / or extinguishing powder and / or extinguishing earth, is incorporated. The numerous solid particles encompassed by the intermediate layer can thus be bound together by a binder or incorporated into a material matrix to provide a coherent solid body as an intermediate layer. The material matrix or the binder is then selected such that it also melts at least locally under the influence of a specific heat.Under the influence of a specific heat, the solid substance provided by the binder or material matrix transitions from a solid to a viscous state, allowing the intermediate layer to become at least locally fluid. This allows it to penetrate through the resulting opening in the outer layer and cover the component to be extinguished beneath, thereby smothering the fire. During manufacturing, the numerous solid particles of the solid extinguishing agent can be coated and / or mixed with the binder and pressed to form the intermediate layer. Alternatively, the particles can be mixed with the binder or material matrix in a viscous state and formed into the intermediate layer using an injection molding process or similar method. In this case as well, it is preferred that the solid substance be non-combustible.

[0027] The binder, also known as a binding agent, can be present during the production of the intermediate layer in a liquid and / or viscous state, or in solid form, for example, in granular form and / or as a powder. In the latter case, the binder can be melted, for example, by compression and / or the application of heat, to bond the solid particles with it. Subsequently, the binder can harden and form a cohesive solid with the solid particles. The intermediate layer can also consist solely of the binder or matrix and the numerous solid particles. Under certain heat conditions, the binder or the material matrix may fail, for example, by melting, becoming pulverized, and so on.

[0028] By combining the solid particles of the solid extinguishing agent with the matrix or binder, a reinforcing property for the cover plate can be provided, especially in non-fire situations. When the intermediate layer forms a cohesive solid, the cover plate is significantly stiffer. The cover plate can therefore also function as a housing lid for a battery casing. However, additional or alternative stiffening properties can also be provided by other measures, as will be explained in more detail later.

[0029] According to a further advantageous embodiment of the invention, the solid extinguishing agent comprises, as the solid particles, in particular of the extinguishing granules and / or extinguishing powder and / or extinguishing earth, at least one or more or all of the following types of particles: glass spheres, hollow glass spheres, expanded glass, expanded clay, alumina, metal spheres, in particular made of steel, hollow metal spheres, in particular made of steel, ceramic particles, ceramic spheres, hollow ceramic spheres, sand and / or stone flour.

[0030] The materials from which the particles of the solid extinguishing agent are made can include, for example, glass, expanded glass, expanded clay, alumina, metal (especially steel), ceramics, sand, and / or stone. The particles can be in the form of spheres or hollow spheres, or they can have a geometrically arbitrary or random structure, as is the case with sand, stone dust, or alumina. In particular, a corresponding powder can be produced from all of the aforementioned materials, which then also exhibits microparticles with arbitrary geometry. Furthermore, the solid extinguishing agent can comprise any combination of the aforementioned particle types, especially with regard to material, geometry, and / or particle size. The liquid extinguishing agent can therefore consist of, for example, only one of the aforementioned particle types, or it can comprise several or all of the different particle types.

[0031] The use of hollow spheres is highly advantageous in terms of reducing the weight of the granules or powder. The same applies to the use of expanded glass granules or powder. This is based on the understanding that expanded glass possesses numerous beneficial properties. Expanded glass can be supplied in granular form. Expanded glass, especially expanded glass granules, is a building material made from recycled glass. This makes expanded glass very sustainable. Expanded glass is foamed glass with small, gas-filled pores and can be produced in various grain sizes. Due to its porosity, expanded glass, like expanded clay or similar granules, is exceptionally lightweight. Furthermore, expanded glass is extremely temperature-resistant, especially compared to plastics or, for example, aluminum.Specialized shaping with a specific geometry, for example in the form of spheres or hollow spheres, is therefore not required. This enables particularly cost-effective production of the expanded glass granules.

[0032] Particularly fine-grained substrates used as solid extinguishing agents, such as powders, have a particularly good oxygen-cutting or fire-smothering effect.

[0033] According to a further advantageous embodiment of the invention, the cover plate comprises at least one functional layer, which is designed as the cover plate or is joined to the cover plate, and which comprises at least one of the following layers: a reinforcing layer comprising reinforcing fibers and / or an organosheet and / or a fiber composite panel and / or a woven fabric and / or nonwoven fabric and / or knitted fabric and / or fleece made of the reinforcing fibers. Such a reinforcing layer advantageously increases the stiffness of the cover plate. This allows the cover plate, for example, to simultaneously form or provide a lid for a battery housing. Such reinforcing fibers can be designed, for example, as glass fibers and / or carbon fibers and / or aramid fibers, and the like. Ceramic fibers or similar materials are also suitable as the stiffening layer or reinforcing fibers.These reinforcing fibers can be provided in a wide variety of forms, such as woven, non-woven, knitted, or fleece fabrics. Especially when a component, particularly the surface layer, is made of plastic, such a reinforcing layer can be easily integrated into the surface layer, for example, using injection molding, compression molding, or similar processes. However, the reinforcing layer can also be a separate layer that is then attached to the surface of the surface layer, for example, by thermal bonding, welding, compression molding, gluing, or similar methods.

[0034] Additionally or alternatively, at least one functional layer can be provided in the form of a metallic electromagnetic shielding layer, particularly in the form of a metal foil and / or a metal mesh and / or a metal grid, or it can include such a shielding layer. This allows for particularly good EMC properties. Such a shielding layer can be attached to the outside of the cover layer in the same way as already described for the reinforcement layer, or it can be integrated into the cover layer or the cover plate during its manufacture.

[0035] The at least one functional layer can also additionally or alternatively include a layer containing sensors. This allows sensors to be advantageously integrated into or attached to the cover layer. This is particularly beneficial when the cover plate is a component for a battery housing or a battery itself. In such cases, sensors suitable for battery monitoring can be advantageously integrated into the cover plate in a space-saving and efficient manner. For example, such a sensor can be advantageously bonded directly to the cover layer by melting the plastic. This allows for very gentle integration of the sensor into the cover plate, using low pressure and, most importantly, at low temperatures.The sensor layer can contain a single sensor or multiple sensors, for example, of the same type and / or different types. Such a sensor could be, for example, a temperature sensor, voltage sensor, current sensor, gas sensor, pressure sensor, humidity sensor, or an RFID (radio frequency identification) transponder or chip for structural monitoring, or similar. The sensor layer, that is, the layer containing the sensor technology, can also include contact elements such as conductive traces, wires, cables, or, more generally, electrical conductors. This enables electrical and / or electronic connection of the sensor to, for example, an external control unit or similar device. The contact elements can also be integrated and optionally reinforced with additional fiber-reinforced inserts.Integrating such a sensor(s) into the cover plate can involve covering the sensor with a protective cap during the joining process. This protective cap can also be referred to as a protective housing. This advantageously protects the sensor from excessive pressure during joining. However, such a sensor can also be subsequently integrated or positioned on the cover plate, for example, on the top layer.

[0036] The aforementioned functional layers, or at least one or some of them, can be placed in a mold, particularly a forming tool, a press mold, and / or an injection mold, and optionally vacuum-sealed and / or pressed together, for example, with the top layer or a material forming or encompassed by the top layer. This allows these layers to be attached to or integrated into the top layer in a simple and effective manner. Furthermore, during this manufacturing process, for example, pressing, the top layer can also be attached to the intermediate layer, and / or the outer layer can be attached to the intermediate layer on the opposite side. Therefore, the manufacturing or joining of the individual layers of the top plate does not necessarily have to take place in separate manufacturing steps, but can also be carried out in a single manufacturing step.

[0037] Thus, the aforementioned layers can be easily and effectively attached to the intermediate layer. The outer layer of the cover plate is the lowest layer of the cover plate in its intended installation position, forming the outer boundary of the cover plate towards the component to be protected. The cover plate is accordingly located on the opposite side of the intermediate layer. To integrate the functional layer into the cover plate, it can, for example, be positioned between the intermediate layer and the cover plate, integrated into the cover plate, or placed on the opposite side of the intermediate layer against the cover plate.It is also conceivable that the cover plate comprises several functional layers, for example, one between the intermediate layer and the cover plate, and / or another on the side of the cover plate opposite the intermediate layer, and / or a functional layer integrated into the cover plate, or even several functional layers integrated into the cover plate. The cover plate itself can also be designed as a functional layer. Thus, several of the aforementioned functional layers can advantageously be integrated into the cover plate in a multi-layered structure.

[0038] To form the top layer, a first layer, such as the top layer and / or functional layer, can be placed in a mold, particularly a thermoforming, pressing, and / or injection mold. The intermediate layer or intermediate layer material, e.g., the solid particles with the binder, is then added, and finally the outer layer is applied, joining the entire layered assembly accordingly. The outer layer can be provided, for example, in the form of a film, such as a plastic or metal film. Joining can be achieved, for example, using heat, ultrasound, and / or radiation, such as UV curing, compression molding, and so on.

[0039] According to a further advantageous embodiment of the invention, the cover plate is designed as a lid for a battery housing. Alternatively, it would also be conceivable to arrange the described cover plate, for example, on the underside of such a battery housing lid. It is also conceivable to provide the cover plate as a separate component inside a battery housing, for example, above the battery cells and / or battery modules. The cover plate can then be located between the battery cells or battery modules and a housing lid. However, designing the cover plate as a lid for the battery housing saves installation space and additional material.

[0040] Furthermore, the invention also relates to a battery for a motor vehicle, which comprises a cover plate according to the invention or one of its embodiments.

[0041] The cover plate can be positioned above the battery cells in a specific direction. This specific direction preferably corresponds to the vehicle's vertical orientation relative to the battery's intended installation position in a motor vehicle.

[0042] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle. The motor vehicle can be designed as an electric vehicle.

[0043] The invention may also include a method for fire suppression and a method for manufacturing a cover plate. In the course of a fire suppression method, an electrical component to be protected, e.g., a battery cell of a battery according to the invention or one of its embodiments, may first be provided. Such an arrangement thus comprises the component to be protected and the cover plate arranged above it. The cover plate is arranged with respect to the component, e.g., the at least one battery cell, such that its outer layer faces the component to be protected.Under a specific heat load, the outer layer is destroyed, at least locally within the area of ​​application, forming an opening. A portion of the solid extinguishing agent then escapes from this opening under the influence of gravity. Specifically, this escaping portion of the solid extinguishing agent covers the upper surface of the component to be protected, facing the cover plate, in such a way as to extinguish any fire on the component. Thus, by covering the upper surface of the component to be protected with the solid extinguishing agent, or rather the portion of the solid extinguishing agent that escapes from the opening, the fire is extinguished.

[0044] The manufacturing of the cover plate can be carried out as already described in connection with the cover plate according to the invention and its embodiments.

[0045] Depending on its geometry, the shell can take on the shape of the tool for the component housing, i.e., the cover plate, and be inserted directly into the forming tool, for example, the press tool.

[0046] The housing of an electrical component, for example, a battery housing, can also be composed of several individual housing components or have such housing components, one of which may be provided, for example, by the cover plate according to the invention or one of its embodiments. Such a manufacturing process allows for the simple integration of further functions into the cover plate, for example, in the form of an EMC layer, a sensor layer, a reinforcement layer, or the like. The cover plate can also be provided as a housing component, in particular a cover, for power electronics or another electrical component, or be arranged within a housing of such an electrical component, in particular above the component to be protected. Such an electrical component may be another high-voltage component that is different from a high-voltage battery.

[0047] The shell or cover layer can, as described, comprise at least one functional layer or even constitute such a layer itself. Joining the shell or cover plate to a housing component, for example, a housing cover, can be carried out in the same step as manufacturing the cover plate itself, for example, during pressing using a press and / or injection molding machine, particularly in the injection molding process and / or blow molding process and / or forming process.

[0048] The invention also includes further developments of the methods according to the invention, which have features already described in connection with the further developments of the cover plate according to the invention. For this reason, the corresponding further developments of the methods according to the invention are not described again here.

[0049] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0050] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of part of a battery with a cover plate according to an embodiment of the invention; Fig. 2 a schematic representation of the part of the battery made of Fig. 1 after at least partial destruction of the outer layer of the cover plate according to an embodiment of the invention; Fig. 3 a schematic representation of the part of the battery made of Fig. 1 and Fig. 2, in which the fire was extinguished by the released solid extinguishing agent, according to an embodiment of the invention; Fig. 4 a schematic representation of part of a battery according to a further embodiment of the invention; Fig. 5 a schematic representation of the part of the battery made of Fig. 4 after at least partial destruction of the outer layer of the cover plate according to an embodiment of the invention; Fig. 6 a schematic representation of the part of the battery made of Fig. 4 and Fig. 5, in which the fire was extinguished by the extinguishing agent that had escaped, according to an embodiment of the invention; Fig. 7 a schematic cross-sectional view of a cover plate according to a further embodiment of the invention; and Fig. 8 a schematic cross-sectional representation of a cover plate according to a further embodiment of the invention.

[0051] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0052] In the figures, identical reference symbols denote functionally equivalent elements.

[0053] Fig. Figure 1 shows a schematic representation of part of a battery 10 with a cover plate 12, which can, for example, be provided as a lid 14 of a battery housing. The battery 10 can also comprise one or more battery cells 16. In this example, the battery 10 comprises a battery module 18 with several battery cells 16, between which cell separators 20 can optionally be arranged.

[0054] The cover plate 12 is located above the battery cells 16 with respect to the depicted z-direction, which can correspond to a vehicle vertical direction with respect to a standard installation position in a motor vehicle. The plate 12 may optionally have a gap between it and the battery cells 16. The cover plate 12 comprises at least one outer layer 22, which defines the outer boundary of the cover plate 12 and faces the battery cells 16. The cover plate 12 also comprises a top layer 24 and an intermediate layer 26, which is arranged between the top layer 24 and the outer layer 22. In this example, the cover plate 12 includes a shell 28, which encompasses both the top layer 24 and the outer layer 22. Additionally, the shell 28 may also include side elements 30, for example, side walls, through which the top layer 24 and the outer layer 22 are connected.The shell 28 can be designed to enclose, in particular completely enclose, an interior space 32 in which the intermediate layer 26 is located. The outer layer 22, the cover layer 24, and the optional side elements 30 can be made in one piece, in particular from the same material, or from different materials, for example, as separate components and joined together.

[0055] The outer layer 22 is designed to be at least locally destructible, for example, meltable, under a certain temperature. The outer layer 22 can be made, for example, of a thermoplastic material and / or a metal with the lowest possible melting point, and can be designed to be very thin, for example, as a film 22a, such as a plastic or metal film. For example, plastic films and / or composite films, as well as metallic films that melt or rupture at approximately 300 to 700 °C, can be used as the shell 28 or at least as the outer layer 22. The remaining shell 28, in particular the cover layer 24, can optionally be designed to be thicker, for example, as a dimensionally stable housing component, or also as a film.

[0056] Within the interior 32, or between the outer layer 22 and the cover layer 24, a solid extinguishing agent 34 is incorporated as part of the intermediate layer 26, for example in the form of granules 34a or powder 34a. The solid extinguishing agent 34 thus comprises numerous solid particles 36, or the solid extinguishing agent 34 can consist of such solid particles 36. In the present example, the intermediate layer 26 consists of these solid particles 36, which are incorporated in the interior 32 in the form of granules 34a or powder 34a, and can, in particular, completely or almost completely fill it. The solid particles 36 are therefore mobile relative to one another in the present example.

[0057] If a battery cell 16 catches fire, as illustrated in this example for battery cell 16a with a schematic flame 38, this fire 38 leads to a corresponding heat effect at least in a certain area of ​​influence 40 of the outer layer 22, whereby the outer layer 22 is destroyed, for example melted, at least in the area of ​​influence 40, forming a corresponding opening 42, as shown in Fig. 2 is shown schematically.

[0058] Fig. Figure 2 shows a schematic representation of part 10 of battery 10. Fig. 1, in which such an opening 42 has now formed in the outer layer 22 due to the heat of the fire 8. The outer layer 22 can melt locally in such a way that parts 22b of the melted outer layer 22 provide a funnel function. Through the opening 42, at least a part 26a of the intermediate layer 26 can now escape and, in particular, fall downwards due to gravity. A part 26b of the intermediate layer 26 can remain in the interior 32, in particular above undamaged parts 22c of the outer layer 22.

[0059] The escaping granules 34a fall onto the battery cell 16a below and extinguish the fire 38. This is shown schematically in Fig. 3 shown. This means that fire 38 can be extinguished advantageously.

[0060] The intermediate layer 26 thus functions as a fire-resistant layer, which is placed above the component to be protected, in this example the battery cells 16, and is contained within a protective shell 28. In the event of a fire 38, this shell melts and releases the fire-resistant agent, namely the solid extinguishing agent, in this example in the form of granules 34a. The solid extinguishing agent 34a therefore performs an extinguishing function in the event of a fire 38 by preventing the supply of oxygen. As a result of the heat exerted by the fire 38 on the cover plate 12, the shell 28, in particular the outer layer 22, can be partially or completely destroyed, thus releasing the fire-resistant agent, namely the solid extinguishing agent 34a. The fire-resistant agent 34a then spreads over the burning cell 16a, or more generally, the electrical component to be protected, and extinguishes the fire 38 by depriving it of oxygen or preventing its supply.

[0061] The fire protection agent 34 can be placed in the casing 28 in such a way that it is only released in the event of a fire 38 by destroying the casing 28 at the fire site 40, i.e. the area 40 of heat exposure, and possibly also completely.

[0062] The fire protection agent 34, in particular the entire intermediate layer 26, can be compressed into a solid layer or plate within the casing 28, for example by vacuum sealing. This is possible even if the intermediate layer 26 does not constitute a continuous solid, but rather, as in this example, consists of numerous individual particles 36 that are movable relative to one another. Furthermore, other stiffening measures are also possible, as will be explained later. This makes it possible, for example, to design the plate 12 itself as a housing cover 14. Alternatively, the plate 12 can also be attached to and connected with a separately provided housing cover 14. This improves, for example, the acoustics, stiffness, thermal insulation, and so on of such a cover 14 and allows for designs that depend on the requirements of the housing component, namely, in this case, the housing cover 14.

[0063] It is also advantageous if the casing 28, or at least the cover layer 24, consists of a material, for example a composite material, that allows direct application to such a separate housing cover 14. The casing 28 or the cover layer 24 can, for example, be a plate-shaped component with an adhesive layer, or a plastic layer that melts at low temperatures, or something similar.

[0064] Various options are available for the granules 34a. The particles 36 are made primarily of a highly temperature-resistant and non-combustible material, such as glass (especially expanded glass), clay (especially expanded clay), steel, ceramic, sand, stone, mica, or similar materials. These materials can be present in powder or granular form as the solid extinguishing agent 34. Thus, the fire retardant 34, for example expanded glass in granular form, can be easily released and prevent the oxygen supply.

[0065] Fig. Figure 4 shows a schematic representation of part of a battery 10 with a cover plate 12 according to a further embodiment of the invention. The battery 10, and in particular the cover plate 12, can be designed as described above, except for the differences described below. These differences relate essentially to the design of the intermediate layer 26, which now comprises, in addition to the solid extinguishing agent 34 in granular form 34a, an additional binder 44 or a material matrix. The binder 44, and analogously a material matrix, allows the particles 36 to be bonded together to form a cohesive solid as the intermediate layer 26. The binder 44 thus binds the particles 36 together in such a way that they are no longer mobile relative to one another.The binder 44 is designed such that it melts, at least locally, under the influence of a corresponding heat exposure, which occurs during a fire 38 on the cover plate 12. The functional principle of the cover plate 12 is the same as that previously described in connection with . Fig. 1 to Fig. 3 described. Therefore, if a fire 38 occurs, the resulting heat exposure to the outer layer 22 leads at least to a local opening 42 in this layer, through which at least a part 26a of the intermediate layer 26 can escape through the opening 42, as shown schematically in Fig. Figure 5 shows that the heat applied to plate 12 also makes the binder 44 of the intermediate layer 26 at least partially viscous, melted, or pulverized, so that it can easily escape from the opening 42 and cover the top surface 16b of cell 16a, as shown schematically in Figure 5. Fig. Figure 6 is shown. This in turn cuts off the oxygen supply and smothers the fire (Figure 38).

[0066] Fig. Figure 7 shows a schematic representation of a cover plate 12 according to a further embodiment of the invention. In this example, the cover plate 12 comprises at least one functional layer 46, which in this example is simultaneously provided as a cover layer 24. The cover layer 24 can therefore be made of a different material or material composition than the remaining shell 28 or at least the outer layer 22, which can be designed as previously described. The functional layer 46 can, for example, be an EMC protection layer and / or a reinforcement layer and / or a sensor layer or the like. This allows the plate 12 to be advantageously equipped with additional functions.Further functions of the plate 12 can therefore advantageously be provided in the form of one or more additional layers 46 for integrating additional properties, which can also be provided on only one side of the plate 12, for example, the side of the plate 12 facing away from the battery cells 16 or the component to be protected. Stiffening measures are particularly advantageous so that the plate 12 can, for example, simultaneously be used as a housing cover 14. The layers 46 can be integrated during the manufacturing of the plate 12. This eliminates the need for additional joining steps in the housing component or cover 14 for integrating further layers or functions.

[0067] Precisely because manufacturing processes such as injection molding, compression molding, or similar methods allow for the easy integration of further functions in the form of such layers 46, the plate 12 produced in this way is particularly suitable as a housing component, especially a cover, for a high-voltage component, in particular a high-voltage battery or, more generally, an electrochemical energy storage device, or also for power electronics. In principle, however, the manufactured cover or top plate 12 can be part of a housing for any electrical component, preferably a high-voltage component.

[0068] The functional layer 46 can also be provided in addition to the cover layer 24, as shown schematically in Fig.Figure 8 illustrates this. Here, a functional layer 46, which can be configured as described above, is arranged on the side of the top layer 24 facing away from the intermediate layer 26. The arrangement of the functional layer 46 can take place after the manufacturing and arrangement of the outer layer 22, intermediate layer 26, and top layer 24 relative to each other, or even in the same process step.

[0069] In particular, several different functional layers 46 can also be provided, which are integrated into and / or attached to the top layer 24.

[0070] Overall, the examples demonstrate how the invention can provide a fire-resistant layer for extinguishing a battery cell or an electrical component. According to one embodiment, a battery cover filled with an extinguishing agent can be provided. In the event of a cell fire, the cover melts, releasing the extinguishing agent and thus preventing thermal runaway. Therefore, a cover filled with fire-resistant agent can be placed over the component requiring protection, which may pose a fire hazard. The heat generated by the melting agent releases the fire-resistant agent, which then extinguishes the flames on the component. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 107 675 A1

[0003] DE 10 2016 203 553 A1

[0004] DE 10 2022 001 079 A1

[0005] WO 2019 / 224 013 A1

[0006]

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