Electrical energy storage, manufacturing process and vehicle

Abstract

The invention relates to an electrical energy storage device (2) for a vehicle (1) with at least one cell module (4) arranged in a housing (3), which comprises a number of electrically interconnected individual cells (4.1) forming a cell stack, wherein an end plate (5) is arranged at each end of the cell stack in the stacking direction (S). According to the invention, a compression element (9) for compensating for cell thickness growth of the individual cells (4.1) is arranged on a free flat side of the respective end plate (5) between this end plate and the housing (3). The invention further relates to a method for manufacturing the electrical energy storage device (2) and a vehicle (1) with such a device.

Description

[0001] The invention relates to an electrical energy storage device for a vehicle with at least one cell module arranged in a housing, which comprises a number of electrically interconnected individual cells forming a cell stack, wherein an end plate is arranged at each end of the cell stack in the stacking direction. The invention further relates to a method for manufacturing the electrical energy storage device and a vehicle with an electrical energy storage device.

[0002] A battery arrangement for a motor vehicle is known from DE 10 2021 002 803 A1. The battery arrangement comprises a battery housing and a cell module, which is arranged on a base plate of the battery housing. The cell module comprises a cell module housing and a plurality of battery cells arranged in the cell module housing. A base of the cell module housing is bonded to the base plate of the battery housing by means of an adhesive. The cell module housing is bonded to a side wall of the battery housing by means of a further adhesive. This further adhesive has a higher shear strength than the adhesive applied between the base of the cell module housing and the base plate of the battery housing.

[0003] The invention is based on the objective of providing an electrical energy storage device for a vehicle, a method for manufacturing the electrical energy storage device and a vehicle with an electrical energy storage device.

[0004] The problem is solved according to the invention by an electrical energy storage device which has the features specified in claim 1, by a method which has the features specified in claim 7, and by a vehicle which has the features specified in claim 8.

[0005] Advantageous embodiments of the invention are the subject of the dependent claims.

[0006] An electrical energy storage device for a vehicle comprises at least one cell module arranged in a housing, which includes a number of electrically interconnected individual cells forming a cell stack, with an end plate arranged at each end of the cell stack in the stacking direction. According to the invention, a compression element for compensating for cell thickness growth of the individual cells is arranged on a free flat side of the respective end plate between this end plate and the housing.

[0007] The compression element compensates for charging- and / or aging-related cell thickness growth in the individual cells of the cell module by compressing the element itself. The compression element thus provides a compression space for cell thickness growth, with the counterforce of the compression element increasing as the cell thickness growth increases. Furthermore, the compression element is positioned on a flat side of an end plate in such a way that it largely prevents the injection of fixing adhesive and / or potting compound from flowing into areas of the housing where such adhesive and / or potting compound could have a detrimental effect.

[0008] Furthermore, by arranging the compression elements, the available space in the housing can be used efficiently for arranging individual cells, since the cell thickness growth can be largely compensated for by means of the compression elements.

[0009] In one embodiment, the compression element is flat and has a height dimension that is less than the height dimension of the end plate. However, the height of the compression element is greater than the filling height of the fixing adhesive and / or potting compound. This allows the compression elements to largely compensate for cell thickness growth. The thickness and elastic deformability of the compression elements are also predetermined.

[0010] In one possible embodiment, the compression element is formed from a compressible foam, the foam having a predetermined temperature resistance, so that the compression element can compensate for the cell thickness growth of the individual cells over a comparatively long period of time without becoming porous and / or brittle.

[0011] In another embodiment, a fixing adhesive and / or a potting compound is filled into a space formed between an end plate with a compression element and a housing side wall. The compression element is uncompressed, so that after the fixing adhesive and / or potting compound is added, it is able to compensate for the cell thickness growth of the individual cells. Furthermore, the individual cells are fixed in the housing of the electrical energy storage device, at least by means of the fixing adhesive and / or potting compound and the compression elements, in a form-fitting manner.

[0012] In one embodiment, the cell module is fixed to the bottom of the housing by means of a thermally conductive adhesive, so that the cell module is essentially held securely against slipping inside the housing.

[0013] In another possible embodiment, the individual cells are cuboid in shape and lie against each other with their flat sides in the stacking direction, so that the cell module can expand due to loading and / or aging and this cell thickness growth is compensated by means of the compression elements.

[0014] Furthermore, the invention relates to a method for manufacturing an electrical energy storage device, wherein - a compression element is applied to a free flat side of the respective end plate, - the cell module is placed on a layer of thermally conductive adhesive applied to the bottom of the housing and - the cell module is fixed to the floor after the thermally conductive adhesive has hardened.

[0015] The compression elements compensate for cell thickness growth that occurs during charging of the electrical energy storage device and / or due to aging, by compressing the respective compression element so that the available space provided by the housing of the electrical energy storage device can be used in an optimized way.

[0016] Furthermore, the invention relates to a vehicle with an electrical energy storage device, in particular a vehicle electrical system battery. The electrical energy storage device comprises at least one cell module arranged in a housing, which includes a number of electrically interconnected individual cells forming a cell stack. An end plate is arranged at each end of the cell stack in the stacking direction, and a compression element is arranged on a free flat side of each end plate to compensate for cell thickness growth caused by charging and / or aging. If the individual cells expand, for example during a charging process, the respective compression element is compressed, providing the necessary installation space.

[0017] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0018] This shows: Fig. 1. Schematic top view of a vehicle with an electrical energy storage system and Fig. 2 schematically a cross-sectional view of the electrical energy storage device.

[0019] Corresponding parts are marked with the same reference symbols in all figures.

[0020] Fig. Figure 1 shows a top view of an exemplary and highly simplified vehicle 1 with an electrical energy storage device 2, in particular a vehicle on-board battery, and in Fig. Figure 2 shows a cross-sectional view of the electrical energy storage device 2.

[0021] The electrical energy storage device 2 has a housing 3 in which a cell module 4 with a predetermined number of individual cells 4.1 is arranged, wherein the individual cells 4.1 are electrically connected in series and / or parallel. The individual cells 4.1 are cuboid in shape and are stacked to form the cell module 4, with an end plate 5 arranged at each end of the cell module 4 in the stacking direction S, by means of which the cell module 4 is clamped, so that a compact unit is formed. The efficiency of the individual cells 4.1 can also be increased if a certain pressure is exerted on the individual cells 4.1.

[0022] During operation of the individual cells 4.1, particularly during charging and / or with increasing age, the individual cells 4.1 exhibit cell thickness growth, expanding, especially in the stacking direction S. For this purpose, it is necessary to provide a growth space within the housing 3 of the electrical energy storage device 2, allowing each individual cell 4.1 to expand due to its increased internal pressure without bursting.

[0023] Typically, a cell module 4 is bonded to a plate-shaped temperature control plate (not shown) at the base 3.1 of the housing 3 using a thermally conductive adhesive 6. The cell module 4 is then bonded to the side walls 3.2 of the housing 3 by means of side plates 7 using a fixing adhesive 8 and / or a potting compound, thus securing it in place. To prevent the fixing adhesive 8 and / or potting compound from flowing into areas of the housing 3 where its presence could be detrimental, flow barriers are incorporated into the housing 3.

[0024] In order to ensure that the individual cells 4.1 are fixed, that such a flow barrier can be omitted and that a growth space is available for the cell thickness growth of the individual cells 4.1, the electrical energy storage device 2 is designed as described below.

[0025] A compression element 9, formed from a compressible foam, is arranged on a free flat side of each end plate 5. The compression element 9 is planar and has a height that is less than the height of the free flat side of the end plate 5.

[0026] By means of the respective compression element 9, the cell thickness growth of the individual cells 4.1 can be compensated for by its compression with respect to a dimension of the cell module 4 in the stacking direction S and thus a longitudinal axis of the cell module 4. This means that a length dimension of the cell module 4 remains essentially the same with and without cell thickness growth.

[0027] In the manufacture of the electrical energy storage device 2, a compression element 9 is applied to the free flat side of the respective end plate 5. The cell module 4, comprising the individual cells 4.1 and the end plates 5 with compression element 9, is placed as a compact unit onto a layer of thermally conductive adhesive 6 applied to the base 3.1 of the housing 3. Subsequently, a space formed by a flat side of the respective compression element 9 opposite the individual cells 4.1 and a side wall 3.2 of the housing 3 arranged parallel to these, is filled with the fixing adhesive 8 and / or the potting compound to a predetermined height. The filling height is less than the height dimension of the respective compression element 9. When the fixing adhesive 8 and / or the potting compound is filled into the space, the respective compression element 9 has its uncompressed initial shape.

[0028] The cell module 4 is fixed in the housing 3 by means of the hardened fixing adhesive 8 and / or the hardened potting compound.

[0029] The compression element 9 attached to the respective end plate 5 serves to adjust the space for the fixing adhesive 8 and / or the potting compound to be poured and to compensate for the cell thickness growth of the individual cells 4.1, whereby the higher the compression of the compression element 9, the higher the counter-pressure that acts on the individual cells 4.1 in the stacking direction S by means of the end plates 5.

[0030] An arrangement of a busbar (not shown in detail) for the electrical interconnection of the individual cells 4.1 is simplified in such a design of the electrical energy storage device 2, since possible mechanical influences, in particular due to cell thickness growth, can be reduced by means of the compression elements 9. Reference symbol list 1 vehicle 2 electrical energy storage devices 3 cases 3.1 Floor 3.2 Side wall 4-cell module 4.1 Single cell 5 End plate 6 Adhesive 7 side panel 8 Fixing adhesive 9 compression element S Stacking direction 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 2021 002 803 A1

[0002]

Claims

Electrical energy storage device (2) for a vehicle (1) with at least one cell module (4) arranged in a housing (3), which has a number of electrically interconnected individual cells (4.1) forming a cell stack, wherein an end plate (5) is arranged at each end of the cell stack in the stacking direction (S), characterized in that a compression element (9) for compensating for cell thickness growth of the individual cells (4.1) is arranged on a free flat side of the respective end plate (5) between this and the housing (3). Electrical energy storage device (2) according to claim 1, characterized in that the compression element (9) is designed as a flat surface and has a height dimension that is selected to be smaller than a height dimension of the end plate (5). Electrical energy storage device (2) according to claim 1 or 2, characterized in that the compression element (9) is formed from a compressible foam. Electrical energy storage device (2) according to one of the preceding claims, characterized in that a fixing adhesive (8) and / or a potting compound is filled into a space formed between an end plate (5) with compression element (9) and a housing side wall (3.2). Electrical energy storage device (2) according to one of the preceding claims, characterized in that the cell module (4) is fixed to a base (3.1) of the housing (3) by means of a thermally conductive adhesive (6). Electrical energy storage device (2) according to one of the preceding claims, characterized in that the individual cells (4.1) are cuboid in shape. Method for manufacturing an electrical energy storage device (2) according to one of the preceding claims, wherein - a compression element (9) is applied to a free flat side of the respective end plate (5), - the cell module (4) is placed on a layer of thermally conductive adhesive (6) applied to the base (3.1) of the housing (3), and - the cell module (4) is fixed to the base (3.1) after the thermally conductive adhesive (6) has cured. Vehicle (1) with an electrical energy storage device (2) which is designed according to one of claims 1 to 6 and is manufactured by means of a method according to claim 7.

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