Battery cover

Abstract

Battery cover for a battery housing with a body (12) having a sandwich structure, with at least two cover layers (30, 32, 34, 36) between which a core layer (40) made of a thermoplastic polymer material is provided.

Description

[0001] The invention relates to a battery cover, in particular a battery cover for a battery that is provided in a motor vehicle, for example, to supply power to the drive system. The invention further relates to a battery housing with such a battery cover.

[0002] Batteries, such as lithium-ion batteries and nickel-metal hydride batteries, typically have a battery casing to house the power-generating elements. This battery casing is usually sealed with a battery cover.

[0003] Requirements for such a battery housing, and therefore for the battery cover, include sufficient mechanical stability and rigidity to prevent exceeding a maximum deflection, compliance with electromagnetic compatibility (EMC) specifications, adequate sealing, a lightweight design, and a minimal footprint to allow for easy installation in inaccessible and confined spaces. Furthermore, it may be necessary to incorporate cooling or a mounting bracket for cooling within or on the battery housing. This may require a flat base. Additionally, it may be necessary to mount a battery management system on the battery housing.

[0004] It is of particular importance that the cover can be securely connected to the battery housing, e.g. by means of a screw connection, so that sufficient sealing and rigidity are ensured in this area as well.

[0005] Solutions with battery covers made of metal, e.g. steel or aluminum, or of reinforced metal, e.g. with plastic ribs, are known.

[0006] German patent application DE 11 2021 001 687 T5 describes a battery cover with a metal plate formed integrally with a valve and a plate section surrounding the valve. The valve is configured to break open when a predetermined pressure is applied to it. For this purpose, the valve has a pressure-bearing plate section designed to be bent out of a bending groove by pressure, and a thin plate section with a fracture groove having a specific depth in one thickness direction.

[0007] The disadvantages of such battery covers are, firstly, their high weight and, secondly, their high manufacturing costs. Furthermore, it should be noted that some designs of the battery cover do not achieve sufficient rigidity. In addition, the manufacturing process proves to be complex. Finally, corrosion problems must be taken into account.

[0008] Against this background, a battery cover with the features of claim 1 and a battery housing according to claim 13 are presented. Embodiments are described in the dependent claims and in the description.

[0009] A battery cover for a battery housing is presented. This battery housing is designed to hold a battery or the power-generating components of a battery and is therefore a component of that battery.

[0010] The battery cover has a body with a sandwich structure. This sandwich structure comprises at least two outer layers, between which a core layer made of a thermoplastic material is inserted or provided. This means that at least one outer layer is provided on one side or top, and a corresponding number of outer layers are typically provided on the other side or bottom, with the core layer inserted between the two sides.

[0011] The core layer can also be described as a matrix made of a thermoplastic material. The sandwich structure of the body or battery cover can also be described as a composite structure.

[0012] If two cover layers are provided, each of these cover layers has two sides, namely a first side that rests against the core layer, and a second side that forms an outer surface of the body of the battery cover.

[0013] In one embodiment, two first cover layers and two second cover layers are provided, with the core layer positioned between the two first cover layers and the two second cover layers. Thus, two core layers are provided on each side of the core layer. Of these two cover layers, one is the inner cover layer, which abuts the core layer. The other cover layer then forms an outer surface of the body.

[0014] The core layer of the battery cover body can have a geometry selected from a group consisting of: honeycomb, foam, ribs.

[0015] A film-based core layer made of a thermoplastic material can be used as the core layer.

[0016] Furthermore, the core layer can be made of an unreinforced or reinforced, in particular fiber-reinforced, plastic material.

[0017] The fibers for reinforcing the core layer can be selected from: short fiber, long fiber, random fiber.

[0018] The core layer of the battery cover body is typically bonded to the two adjacent outer layers. The body can then form a sandwich component in which the outer layers and the core layer are designed as a compacted and bonded multilayer laminate.

[0019] Furthermore, the body's outer layers may be made at least partially of a plastic material that includes at least one of the following elements from the group that includes: UD (Unidirectional), Random Fibre, Woven Fabric, Continuous Fiber, Long or Short Fiber Reinforced Plastic.

[0020] The battery cover may still have embossed markings on its outer surface. In this case, the battery cover typically has a locally reduced wall thickness.

[0021] Furthermore, structures such as ribs may be attached to the outside of the battery cover or the body of the battery cover.

[0022] Furthermore, an EMC foil, e.g. made of aluminium, can be attached to the outside, at least in sections, which can be advantageous with regard to the requirements for electromagnetic compatibility (EMC).

[0023] The described battery housing has a base housing that is either closed with the battery cover or is closed with it. For this purpose, the battery housing or its base housing typically has an opening that is closed with the battery cover, e.g., by screwing it on.

[0024] The battery cover is therefore designed in particular as a malleable thermoplastic, reinforced composite structure which has at least two layers in which fibers are embedded in a matrix of thermoplastic polymer material.

[0025] The battery cover presented here is manufactured using a thermoplastic honeycomb sandwich. This material is thermoformable, recyclable, and inexpensive to produce. Furthermore, an embossing can be applied to adapt the cover to the available space.

[0026] In addition, it is possible to thermally and / or mechanically weld the battery cover to other structures, such as a bracket and ribs, using injection-molded parts, molded parts, and semi-finished products. This also facilitates functional integration.

[0027] Furthermore, the battery cover or the entire battery housing with battery cover can be covered and thus laminated with an EMC foil, such as aluminum. Local embossing is also possible, in particular partial or complete embossing or compaction across the wall thickness.

[0028] The presented battery cover allows for secure screwing to the battery housing, closed edge areas and good adaptation options to the available installation space.

[0029] Targeted weakening of designated areas makes it possible to achieve sufficient flexibility as needed, e.g. also for hinges and joints.

[0030] Embodiments of the presented battery cover provide for the use of different materials and material compositions, especially for cover layers, particularly reinforced with, for example, UD (unidirectional), randomly woven fiber, fabric, continuous fiber, long or short fiber.

[0031] Materials such as carbon or glass can be used for fiber reinforcement. The core material is typically a foil-based honeycomb core made of thermoplastic material, with or without fiber reinforcement.

[0032] The core of the battery cover typically features a geometry with honeycomb, foam, and / or ribs. Furthermore, ribs or other structures can be applied using thermal and / or mechanical bonding.

[0033] A method for manufacturing such a battery cover will be presented.

[0034] This process typically involves a press-based thermoforming process with upper and lower cavities, with or without vacuum. Heating can be performed inside or outside the machine, for example, via infrared (IR) using quartz or ceramics, heating fields, or convection ovens. A reflector that can be inserted into the machine can be used to achieve locally differentiated energy inputs.

[0035] It has been shown that the output of IR emitters can be individually controlled. Plate handling can be achieved using clamping frames or local grippers, resulting in material savings and improved forming properties. In any case, it is ensured that the required pressing force can be provided.

[0036] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0037] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawing. Brief description of the drawing Fig. Figure 1 shows a top view of an embodiment of the presented battery cover. Fig. Figure 2 shows a section along line AA in Fig. 1 and thus a cut through the battery cover Fig. 1. embodiment of the invention

[0038] The invention is schematically illustrated in the drawing using one embodiment and is described in detail below with reference to the drawing.

[0039] In Fig. Figure 1 shows an embodiment of the battery cover in a top view, which is generally designated by reference numeral 10. The battery cover 10 comprises a body 12 having a first, substantially rectangular section 14 and a substantially trapezoidal second section 16. The two sections 14 and 16 are formed as a single piece or integrally formed together.

[0040] Furthermore, 12 local embossings or indentations 20 are provided on the outer surface of the body shown. At these points, the body 12 has a reduced wall thickness, as is clearly shown in Fig. 2 can be seen.

[0041] Furthermore, the illustration indicates a honeycomb structure 22 inside the body 12. A geometry made of foam, ribs, or a combination of these geometries could also be provided here.

[0042] Fig. Figure 2 shows a section along line AA. Fig. 1. The illustration shows a section through the body 12 of the battery cover 10. The cover layers can be seen, namely on one side 24 or above a first cover layer 30 and a second cover layer 32 and on the other side 26 or below also a first cover layer 34 and a second cover layer 36.

[0043] Between the two sides 24 and 26, i.e., on the first side 24 the two cover layers 30 and 32 and on the second side 26 the two cover layers 34 and 36, a core layer 40 is inserted or embedded, which has the honeycomb structure 22.

[0044] The two opposing inner cover layers 30 and 34 lie with their inner surfaces against the core layer 40 and are typically bonded to it. The two opposing outer cover layers 32 and 34 form the outer surfaces of the body 12 with their outer surfaces.

[0045] As mentioned previously, the representation of the Fig. 2 clearly shows the locally reduced wall thickness of the body 12 caused by the imprints 20. 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 11 2021 001 687 T5

[0006]

Claims

[1] Battery cover for a battery housing with a body (12) having a sandwich structure, with at least two cover layers (30, 32, 34, 36) between which a core layer (40) made of a thermoplastic polymer material is provided. [2] Battery cover according to claim 1, comprising two first cover layers (30, 32) and two second cover layers (34, 36), wherein the core layer (40) is provided between the two first cover layers (30, 32) and the two second cover layers (34, 36). [3] Battery cover according to claim 1 or 2, wherein the core layer (40) has a geometry selected from the group consisting of: honeycomb, foam, ribs. [4] Battery cover according to one of claims 1 to 3, wherein a film-based core layer made of a thermoplastic polymer material is used as the core layer (40). [5] Battery cover according to any one of claims 1 to 4, wherein the core layer (40) is made of an unreinforced plastic material. [6] Battery cover according to any one of claims 1 to 4, wherein the core layer (40) is made of a fiber-reinforced plastic material. [7] Battery cover according to claim 6, wherein the fibers for reinforcing the core layer (40) are selected from: short fiber, long fiber, random fiber. [8] Battery cover according to one of claims 1 to 7, wherein the core layer (40) is bonded to the two adjacent cover layers (30, 34). [9] Battery cover according to any one of claims 1 to 8, wherein the cover layers (30, 32, 34, 36) are made of a plastic material comprising at least one of the following elements from the group comprising: UD (?), random fiber, woven fabric, continuous fiber, long or short fiber reinforced plastic. [10] Battery cover according to one of claims 1 to 9, which is provided with embossing (20) on its outside. [11] Battery cover according to any one of claims 1 to 10, on the outside of which structures such as ribs are attached. [12] Battery cover according to one of claims 1 to 11, on the outside of which at least in sections an EMC film is attached. [13] Battery housing with a base housing which can be closed with a battery cover (10) according to any one of claims 1 to 12. [14] Battery housing according to claim 13, wherein the base housing is closed with a battery cover (10) according to any one of claims 1 to 12.

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