Electrical energy storage

Abstract

Electrical energy storage device (1), in particular for a motor vehicle, comprising a storage housing (2) and a receiving device (6) arranged in the storage housing (2) and designed to receive energy storage cells (5), comprising a foam structure (9) that surrounds the energy storage cells (5) at least partially and a support structure (7) supporting the energy storage cells (5), characterized in that the support structure (7) is foamed in the foam structure (9) at least partially, in particular completely.

Description

[0001] The invention relates to an electrical energy storage device, in particular for a motor vehicle, comprising a storage housing and a receiving device arranged in the storage housing and designed to receive energy storage cells, comprising a foam structure which surrounds the energy storage cells at least in sections, and a support structure supporting the energy storage cells.

[0002] Electrical energy storage devices of the type mentioned above, in particular electrical energy storage devices for motor vehicles, are known in the art, for example, under the name “high-voltage storage devices”. Such electrical energy storage devices have a large number of electrical energy storage cells which are accommodated in a storage housing of the electrical energy storage device. For this purpose, a receiving device is provided in which the energy storage cells are accommodated within the storage housing. The receiving device usually comprises a foam structure, for example a PU foam, which surrounds the energy storage cells at least in sections, and a support structure that supports the energy storage cells. The support structure is usually arranged below the energy storage cells when viewed in the vertical direction and therefore supports the foamed-in energy storage cells “from below”. Forces orAccelerations acting on the electrical energy storage device are thus transmitted through the receiving device, for example from the storage housing to the energy storage cells.

[0003] Firstly, with regard to the defined force transmission, the foam structure is complex to define and produce because it is comparatively soft, so that even with a high variance in different forces and accelerations it must be ensured that the energy storage cells are protected in the foam structure and that the accelerations and forces can be transferred to the energy storage cells in a defined manner. If the energy storage cells are foamed over their entire surface, a defined force transmission is difficult to achieve. Foaming the energy storage cells into the foam structure is also complex because in order to ensure a defined distance between the foam structure and the inner wall of the storage housing and thus positioning the energy storage cells within the storage housing, the electrical energy storage device has to be turned or rotated at least once during production.must be turned so that the bottom area of ​​the storage housing can also be sufficiently foamed. Since the electrical energy storage devices described are comparatively large and heavy assemblies, the implementation of such a manufacturing process is complex in terms of costs and time required.

[0004] The invention is based on the object of providing an electrical energy storage device which is improved in comparison thereto, in which in particular the load distribution or load transmission as well as the production are improved.

[0005] The object is achieved by an electrical energy storage device according to claim 1. The dependent claims relate to possible embodiments.

[0006] As described, the invention relates to an electrical energy storage device, in particular for a motor vehicle. The electrical energy storage device comprises a storage housing, which essentially separates an interior of the storage housing from the surroundings. To accommodate energy storage cells, the electrical energy storage device has a receiving device comprising a foam structure and a support structure. The support structure can be designed, for example, as a plate supporting the energy storage cells. The energy storage cells are supported on the support structure, in particular by means of a cell housing. The foam structure is applied at least in sections around the energy storage cells, and the energy storage cells are specifically foamed within the storage housing.

[0007] The invention is based on the finding that the support structure is at least partially, in particular completely, foamed into the foam structure. As described, the support structure is arranged specifically between the inner wall, in particular the bottom wall, of the storage housing and the energy storage cells. This enables a defined transmission of force between the storage housing and the energy storage cells, in particular the cell housings of the energy storage cells. In other words, the at least one load path or the plurality of load paths between the storage housing and the energy storage cells is not or not decisively guided via the foam structure, but rather via the more suitable support structure. In order to avoid or implement a complex connection of the support structure to the energy storage cells and to the inner wall of the storage housing.To prevent this, the support structure in the electrical energy storage device described herein is at least partially foamed together with the foam structure or foamed by the foam structure. As a result, the support structure is fixed and "anchored" within the storage housing by the foam structure.

[0008] This offers particular advantages with regard to the assembly and production of the electrical energy storage device, as the support structure can be inserted into the storage housing and support the energy storage cells in a defined position. This allows the interior of the storage housing to be filled or foamed with the foam structure, eliminating the need for complex handling of the electrical energy storage device during production, especially turning it over.

[0009] According to one embodiment of the electrical energy storage device, it can be provided that the foam structure and the support structure comprise different materials and form a hybrid component. The hybrid component can thus comprise at least the foam structure and the support structure, which are made of different materials or comprise different materials. The hybrid component can have the support structure as a "skeleton structure", which is surrounded by the foam structure or foamed into it. The different materials of the hybrid component can achieve different properties, for example a defined transmission of the load paths through the support structure and a secure embedding of the energy storage cells in the foam structure. For example, the support structure can be designed as an injection-molded part, whereas the foam structure, as described, is designed as foam, specifically as PU foam.

[0010] The electrical energy storage device can further be developed such that the support structure is more rigid, in particular has a higher modulus of elasticity and / or higher rigidity and / or higher strength than the foam structure. In other words, the described support structure can be more rigid than the foam structure, and thus a defined transfer of loads between the storage housing and the energy storage cells, in particular the cell housing of the energy storage cells, can be achieved. The foam structure, which usually lies fully against the energy storage cells, takes a back seat to the support structure in the transfer of loads, forces and accelerations, since the latter is softer in comparison, and the load path therefore runs preferentially or predominantly through the more rigid support structure.This prevents the full-surface foam structure from exerting stress on the energy storage cells in areas that are not suitable or intended for force transmission. Instead, it ensures that the force transmission or load transfer is carried out in a defined manner by the support structure, particularly at the cell housing of the energy storage cells, especially at the cell jacket in cylindrical energy storage cells.

[0011] According to a further embodiment, the receiving device of the electrical energy storage device can be designed to transmit tensile forces and compressive forces between a lower housing part and an upper housing part of the storage housing by means of the foamed-in support structure. As described, the foaming of the support structure eliminates the need for a complex connection of the support structure to the storage housing; instead, the support structure is fastened within the storage housing by means of the foaming using the foam structure. The foam structure, which on its own is too soft or too undefined in its force transmission, is therefore improved by the support structure, whereby the support structure alone does not have sufficient hold within the storage housing to reliably transmit tensile forces. In other words, the formation of the previously described hybrid component from the support structure and the foam structure advantageously improves the force transmission andLoad transfer of both tensile and compressive forces is possible at suitable locations on the energy storage cells.

[0012] The support structure can also be designed to hold the energy storage cells in an assembled state in a defined z-position, in particular relative to an inner wall of the housing lower part. As described above, in the manufacture of conventional electrical energy storage devices, it is normally necessary to rotate or turn the electrical energy storage device at least once during production in order to ensure the positioning of the energy storage cells relative to the housing upper part and the housing lower part, since in particular the base region between the energy storage cells and the housing lower part cannot be foamed if the electrical energy storage device is positioned in the vertical direction, since the electrical energy storage cells cannot be held in this state. However, the described support structure is explicitly designed to maintain the defined z-position.In other words, the electrical energy storage cells can be supported on the support structure in the assembled state, allowing the electrical energy storage device to be manufactured with a continuous vertical alignment. The z-position of the electrical energy storage cells is maintained in the assembled state, allowing foaming without rotating the electrical energy storage device.

[0013] The electrical energy storage device can be further developed in such a way that the support structure has support elements which support a support plane of the support structure carrying the energy storage cells on the lower housing part, in particular in a spring-elastic manner. The support elements are thus designed to support the support plane, for example the plane of the support structure on which the electrical energy storage cells are arranged, relative to the storage housing, in particular in a spring-elastic manner. The support elements can be understood, for example, as foot elements or “feet” of the support structure which extend between the support plane and the storage housing, in particular the bottom of the storage housing. As a result, a prestressing force can be exerted on the receiving device orthe energy storage cells are brought about, which prestresses the energy storage cells in the vertical direction, for example together with a cell contacting system, optionally with the foam structure interposed, against a housing upper part. In other words, the receiving device in the embodiment described here has a dual function, according to which, on the one hand, anchoring of the support structure, in particular via the support elements, in the foam structure is possible and a defined positioning of the energy storage cells in the z-direction is ensured. This enables a defined force transmission, namely via the load paths formed by the support structure, and simplified assembly is ensured because the z-position of the energy storage cells can be held by the support structure during the assembly process and thus the foam structure can be foamed in without rotating or turning the electrical energy storage device.

[0014] As already described, it is possible for the support structure to be foamed into the foam structure. In one embodiment, it can be provided that the support elements of the support structure, for example the feet or foot elements, are anchored in the foam structure. The support structure can, for example, have a group of support elements for each electrical energy storage cell on the support plane, for example three or four support elements. The exact number of support elements and their geometry can be selected as desired. The support elements can extend, in particular in a curved manner, from the support plane in the direction of the inner wall of the storage housing. Furthermore, a support device can be formed on the support plane for each electrical energy storage cell, namely from a support shape, for example bowl-like, pot-like or basket-like, to which the at least one support element orthe group of support elements is arranged which is assigned to the respective electrical energy storage cell.

[0015] In a further embodiment of the electrical energy storage device, the described support structure can be designed to introduce forces into a cell housing of the energy storage cells. For example, the energy storage cells are positioned on the support plane of the support structure in such a way that only the cell housing is in contact with the support plane. Since, as described, the support structure essentially establishes the connection to the storage housing that defines the load path, it is ensured that force is introduced into the energy storage cells exclusively or predominantly at the cell housing. This allows the load to be transferred to the energy storage cells in a defined manner, preventing the energy storage cells from being subjected to significant stress, for example, at their "base" or "cover."This advantageously achieves, particularly compared to a pure arrangement of the energy storage cells in a foam structure, that forces between a housing upper part and a housing lower part can be guided in a defined manner via load paths that are predetermined by the support structure, so that, compared to the softer foam of the foam structure, a force is introduced specifically into the cell housings, for example the cell jacket, of the electrical energy storage cells.

[0016] In addition to the electrical energy storage device, the invention relates to a motor vehicle having such an electrical energy storage device. Furthermore, the invention relates to a method for assembling an electrical energy storage device, in particular for a motor vehicle, comprising a storage housing and a receiving device arranged in the storage housing and designed to receive energy storage cells, comprising a foam structure that surrounds the energy storage cells at least in sections and a support structure that supports the energy storage cells, wherein the energy storage cells are positioned in the storage housing in an assembled state by means of the support structure and the support structure is foamed in at least in sections together with the energy storage cells.

[0017] All advantages, details, designs, and / or features described with regard to the electrical energy storage device are fully applicable to the motor vehicle and the method. The described method is used in particular for assembling a previously described electrical energy storage device.

[0018] The invention is explained using exemplary embodiments with reference to the figures. The figures are schematic representations and show: Fig. 1 a schematic diagram of an electrical energy storage device in a first assembly state in cross-sectional view; Fig. 2 a schematic diagram of a section of a support structure of the electrical energy storage device of Fig. 1 in perspective view; and Fig. 3 a schematic diagram of the electrical energy storage system of Fig. 1 in a second assembly state in cross-sectional view.

[0019] Fig. Figure 1 shows an electrical energy storage device 1, which is, for example, a component of a motor vehicle, specifically a so-called "high-voltage storage device" designed to supply at least one component of the motor vehicle, specifically an electric machine, with electrical energy. The following description is therefore also applicable to a motor vehicle having such an electrical energy storage device 1.

[0020] The electrical energy storage device 1 comprises a storage housing 2 that separates an interior space 3 from an environment 4. Electrical energy storage cells 5 are arranged within the storage housing 2, the shape, arrangement, and number of which can be freely changed. A receiving device 6 is provided to accommodate the energy storage cells 5 in the interior space 3 of the storage housing 2. Fig. Fig. 1 shows the electrical energy storage device 1 in a first assembly state, in which a support structure 7 of the receiving device 6 together with the energy storage cells 5 has already been introduced into the interior 3. Purely by way of example, a cell contacting system 8 is also shown, which contacts the energy storage cells 5 on their upper side. The receiving device 6 has, in addition to the support structure 7, a foam structure 9, which in a second assembly process or a second assembly state, which in Fig. 3, is introduced or is introduced into the interior 3 and thus foams the energy storage cells 5 and the support structure 7.

[0021] Fig. Figure 2 shows the support structure 7 in an isolated perspective view. The support structure 7 has a support plane 10 on which the energy storage cells 5 are arranged (see Figure 1). Fig. 1, Fig. 3). Purely by way of example, the support plane 10 is designed to support circular-cylindrical energy storage cells 5. In principle, the geometry of the support plane 10 can be adapted to the geometry of the energy storage cells 5, for example, to the shape of the cell casing. Advantageously, the contact between the support plane 10 and the energy storage cells 5 is established such that they are contacted exclusively at the cell casing of the energy storage cells 5. Loads, accelerations, or forces are therefore only introduced into the cell casing, for example, a cell casing.

[0022] The support structure 7 in Fig. 2 also has support elements 11 that extend away from the support plane 10. The support elements 11 can be referred to or considered, for example, as foot elements or feet or supports. Specifically, each energy storage cell 5 arranged on the support plane 10 can be assigned a support device 12 on which the energy storage cell 5 is arranged. Each support device 12 has a support shape 13, for example, bowl-, basket-, or pot-shaped, that connects the support elements 11 to the support plane 10.

[0023] In Fig. 3 shows the second assembly state, for example a fully assembled state, of the electrical energy storage device 1. The foam structure 9 clearly surrounds the energy storage cells 5 as well as the support structure 7 and the cell contact system 8. When the foam structure 9 is introduced, the support structure 7 ensures that the energy storage cells 5 are arranged in a defined z-position, so that the energy storage cells 5 can be foamed in in a defined manner without turning the electrical energy storage device. Furthermore, the support structure 7 defines load paths from an upper housing part 14 to a lower housing part 15 and vice versa. Since the support elements 11 of the support structure 7 contact the inner wall of the storage housing 2, in particular the base, force can be introduced via the support elements 11 into the support structure 7 and thus via the cell housings of the energy storage cells 5 in the vertical direction.

[0024] Since the support structure 7 is particularly more rigid than the foam structure 9, the load paths are defined across the support structure 7, so that the energy storage cells 5 are loaded primarily at their cell housings. The receiving device 6 thus fulfills a dual function, whereby a defined alignment of the energy storage cells 5 is possible by means of the support structure 7 during the assembly process, so that turning the electrical energy storage device 1 is not necessary. Furthermore, the support structure 7 ensures that the load paths run in a defined manner across the cell housings of the energy storage cells 5. The design of the support elements 11 ensures that the support structure 7 is securely anchored within the foam structure 9. The support structure 7 can thus transmit tensile forces and compressive forces in the vertical direction without the need for a complex connection of the support structure 7 to the storage housing 2.The support elements 11 act as “anchors” within the foam structure 9 and thus improve the arrangement or fastening of the support structure 7.

[0025] Based on the shape of the support elements 11, for example shown in Fig. 2, particularly due to the curved shape, spring-elastic support or prestressing is possible through the support structure 7. In other words, the support structure 7 can prestress the energy storage cells 5 and the cell contact system 8 in the vertical direction.

[0026] The advantages, details and features shown and described with reference to the individual embodiments can be combined with one another as desired, are interchangeable and transferable to one another. List of reference symbols 1 electrical energy storage 2 storage enclosures 3 Interior 4 Surroundings 5 Energy storage cell 6 Recording device 7 Support structure 8 Cell contact system 9 Foam structure 10 support level 11 support elements 12 Support device 13 Support form 14 Upper housing part 15 Lower housing part

Claims

[1] Electrical energy storage device (1), in particular for a motor vehicle, comprising a storage housing (2) and a receiving device (6) arranged in the storage housing (2) and designed to receive energy storage cells (5), comprising a foam structure (9) which surrounds the energy storage cells (5) at least in sections and a support structure (7) supporting the energy storage cells (5), characterized by that the support structure (7) is foamed into the foam structure (9) at least in sections, in particular completely. [2] Electrical energy storage device (1) according to claim 1, characterized by that the foam structure (9) and the support structure (7) comprise different materials and form a hybrid component. [3] Electrical energy storage device (1) according to claim 1 or 2, characterized bythat the support structure (7) is more solid, in particular has a higher modulus of elasticity and / or a higher rigidity and / or a higher strength than the foam structure (9). [4] Electrical energy storage device (1) according to one of the preceding claims, characterized by that the receiving device (6) is designed to transmit tensile forces and compressive forces between a lower housing part (15) and an upper housing part (14) of the storage housing (2) through the foamed-in support structure (7). [5] Electrical energy storage device (1) according to one of the preceding claims, characterized by that the support structure (7) is designed to hold the energy storage cells (5) in an assembled state in a defined z-position, in particular relative to an inner wall of the housing lower part (15). [6] Electrical energy storage device (1) according to one of the preceding claims, characterized bythat the support structure (7) has support elements (11) which support a support plane (10) of the support structure (7) carrying the energy storage cells (5) on the housing lower part (15), in particular in a spring-elastic manner. [7] Electrical energy storage device (1) according to claim 6, characterized by that the support elements (11) of the support structure (7) are anchored in the foam structure (9). [8] Electrical energy storage device (1) according to one of the preceding claims, characterized by that the support structure (7) is designed to introduce forces into a cell housing of the energy storage cells (5). [9] Motor vehicle comprising an electrical energy storage device (1) according to one of the preceding claims. [10] Method for assembling an electrical energy storage device (1), in particular for a motor vehicle, comprising a storage housing (2) and a receiving device (6) arranged in the storage housing (2) and designed to receive energy storage cells (5), comprising a foam structure (9) which surrounds the energy storage cells (5) at least in sections and a support structure (7) supporting the energy storage cells (5), characterized by that the energy storage cells (5) are positioned in an assembled state by means of the support structure (7) in the storage housing (2) and the support structure (7) is foamed in at least in sections together with the energy storage cells (5).

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