Electrical energy storage device and method for manufacturing an electrical energy storage device

Abstract

The invention relates to an electrical energy storage device (1) with a housing (2) which is formed by a receiving unit (4) in which at least one cell module (3) with a plurality of electrically interconnected individual cells is arranged, and by a housing cover (5). According to the invention, the receiving unit (4) is formed in one piece and is trough-shaped, and each side of the receiving unit (4) has a vertically projecting tab (4.1 to 4.4), wherein the length of each tab (4.1 to 4.4) corresponds to the length of the side of the receiving unit (4) on which the tab (4.1 to 4.4) is formed, the housing cover (5) is formed in one piece, and each side of the housing cover (5) has a further vertically projecting tab (5.1 to 5.4), wherein the outer dimensions of the housing cover (5) correspond to the outer dimensions of the receiving unit (4), so that in the unlocked state of the housing (2) the further tabs (5.1 to 5.4)4) of the housing cover (5) lie congruently on the tabs (4.1 to 4.4) of the receiving unit (4), and to close the housing (2), the further tabs (5.1 to 5.4) of the housing cover (5) are formed together with the tabs (4.1, 4.4) of the receiving unit (4). The invention further relates to a manufacturing method.

Description

[0001] The invention relates to an electrical energy storage device comprising a housing formed by a receiving unit in which at least one cell module with a plurality of electrically interconnected individual cells is arranged, and by a housing cover. The invention further relates to a method for manufacturing such an electrical energy storage device.

[0002] From DE 10 2010 030 993 A1, a battery cell, a method for manufacturing a battery cell, and a motor vehicle are known. The battery cell housing has a casing and a cover surface that closes one end face of the casing, the cover surface being fixed to the casing by means of a fold. Outside the fold area, the battery cell housing has an element that increases the axial section modulus of the battery cell housing.

[0003] The invention is based on the objective of providing an electrical energy storage device with a housing and a method for manufacturing the 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, and by a method which has the features specified in claim 5.

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

[0006] An electrical energy storage device has a housing formed by a receiving unit in which at least one cell module with a plurality of electrically interconnected individual cells is arranged, and by a housing cover.According to the invention, the receiving unit is designed in one piece and is trough-shaped, and each side of the receiving unit has a vertically projecting tab, wherein the length of the respective tab corresponds to the length of the side of the receiving unit on which the tab is formed, the housing cover is designed in one piece, and each side of the housing cover has a further vertically projecting tab, wherein the outer dimensions of the housing cover correspond to the outer dimensions of the receiving unit, so that in the unlocked state of the housing, the further tabs of the housing cover lie congruently on the tabs of the receiving unit, and to close the housing, the further tabs of the housing cover are formed together with the tabs of the receiving unit.

[0007] Such a housing design can reduce the effort required for joining technology and the number of components needed, thereby streamlining the production environment for manufacturing the electrical energy storage device, especially the housing, and thus achieving cost reductions.

[0008] The receiving unit and / or the housing cover are each made from a sheet metal part, in particular from steel and / or aluminum. This means that mixed connections are also possible, where, for example, the receiving unit is made of steel and the housing cover of aluminum.

[0009] Because the housing cover and the receiving unit are connected in this way, the properties of the housing, particularly with regard to sealing and strength, especially stiffness, can be optimized, for example, in the event of a collision involving a vehicle in whose underbody the electrical energy storage system is located. The stiffening is primarily based on the interlocking tabs of the housing cover and the receiving unit, which are formed on each side, thus optimizing the overall stiffness of the electrical energy storage system even with a lightweight housing design. This reduces the weight of the electrical energy storage system and, consequently, the weight of the vehicle with the electrical energy storage system, thereby increasing the vehicle's performance.

[0010] It may also be possible for the receiving unit and / or the housing cover to be combined with other structural components of the vehicle. In particular, the housing can be integrated relatively well into the vehicle, with the formed tabs being directly attached to and / or within the vehicle.

[0011] The production of the electrical energy storage device with such a housing can be automated, whereby the production can be integrated into already executable production processes in a production environment.

[0012] Furthermore, there is a comparatively good scalability with regard to the housing and thus the electrical energy storage, so that the electrical energy storage can be installed in different vehicles of different vehicle sizes, whereby the electrical energy storage is particularly suitable for installation in or on an electric vehicle.

[0013] By connecting the housing cover to the receiving unit through joint reshaping of the tabs, new design possibilities can be realized, providing flexibility with regard to the design of the electrical energy storage device as well as to cell formats of the electrically interconnected individual cells.

[0014] Furthermore, it is possible to arrange temperature control elements, especially for temperature control of the individual cells, in the housing of the electrical energy storage device.

[0015] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0016] This shows: Fig. 1. Schematic representation of a sectional view of an exploded view of an electrical energy storage device and a procedure for closing the housing of the electrical energy storage device. Fig. 2. Schematic top view of a process for closing the housing, Fig. 3 schematically a sectional view of a first embodiment of formed tabs of a receiving unit and a housing cover, Fig. 4 schematically a sectional view of a second version of formed tabs of a receiving unit and a housing cover, Fig. 5 schematically a sectional view of a third version of formed tabs of a receiving unit and a housing cover, Fig. 6 schematically a sectional view of a fourth embodiment of formed tabs of a receiving unit and a housing cover and Fig. 7 schematically shows a process for closing the housing with a housing cover in an alternative design.

[0017] Corresponding parts are marked with the same reference symbols in all figures.

[0018] Fig. Figure 1 shows, in a highly simplified and exemplary manner, a sectional view of an exploded view of an electrical energy storage device 1 and a procedure for closing a housing 2 of the electrical energy storage device 1.

[0019] In Fig. Figure 2 shows a top view of the process for closing the housing 2.

[0020] In the housing 2, a cell module 3 comprising a plurality of electrically interconnected individual cells is arranged, and several such cell modules 3 can also be arranged in the housing 2.

[0021] The electrical energy storage device 1 is in particular a traction battery of an electric vehicle, a hybrid vehicle or a fuel cell-powered vehicle, wherein the electrical energy storage device 1 is usually arranged in a vehicle floor area of ​​the respective vehicle.

[0022] It is generally known that an electrical energy storage device 1 for a vehicle has a comparatively complex housing 2 and additional frame and structural components to protect against the ingress of moisture and other media, as well as against external mechanical impacts. Manufacturing the electrical energy storage device 1 is comparatively complex due to the large variety of required components and different joining techniques, etc. Furthermore, the electrical energy storage device 1 is heavy, which also increases the vehicle's weight, thus negatively impacting driving characteristics such as the vehicle's range and braking distance.

[0023] In order to reduce the effort involved in manufacturing the electrical energy storage device 1, in particular its housing 2, as well as the weight of the electrical energy storage device 1, the housing 2 is designed as described below.

[0024] The housing 2 has a trough-shaped, one-piece receiving unit 4 and a flat, one-piece housing cover 5. The receiving unit 4 is formed from a sheet of aluminum and / or steel and shaped so that the receiving unit 4 comprises a base area and surrounding side walls.

[0025] Recording unit 4 shows, as in Fig. As shown in Figure 2, a tab 4.1 to 4.4 is provided on each of the four sides, with each tab 4.1 to 4.4 extending over the entire length of the side of the receiving unit 4 on which the respective tab 4.1 to 4.4 is formed.

[0026] The housing cover 5 is plate-shaped and also formed from a sheet metal part which is cut to size, with further tabs 5.1 to 5.4 formed along its sides, each extending over the entire length of the side of the housing cover 5 on which the respective further tab 5.1 to 5.4 is formed.

[0027] The cell module 3 is inserted into the receiving unit 4 and an adhesive 6 is applied to a surface side of the respective tab 4.1 to 4.4 that is directed upwards along a vertical axis.

[0028] The cut housing cover 5 is then placed on the receiving unit 4, whereby, because the outer dimensions of the housing cover 5 correspond to the outer dimensions of the receiving unit 4, the further tabs 5.1 to 5.4 of the housing cover 5 lie congruently on the tabs 4.1 to 4.4 of the receiving unit 4.

[0029] The adhesive 6 applied to the surface of the respective tabs 4.1 to 4.4 of the receiving unit 4 creates a material-bonded connection between the tabs 4.1 to 4.4 of the receiving unit 4 and the other tabs 5.1 to 5.4 of the housing cover 5 when the housing cover 5 is positioned on the receiving unit 4. This material-bonded connection between the receiving unit 4 and the housing cover 5 seals the housing 2 against its environment.

[0030] Subsequently, particularly during or after the curing of the adhesive 6, the respective pairs of tabs 4.1, 5.1 to 4.4, 5.4 which are bonded together are bent over, for example by crimping.

[0031] Furthermore, it is provided that the receiving unit 4 and / or the housing cover 5 have or have a tightly sealable access opening to the interior of the housing 2 (not shown in detail). Through this access opening, the cell module 3 can be electrically contacted and / or a supply line and / or a return line of a temperature control circuit of the electrical energy storage device 1 runs through the access opening(s). In particular, such an access opening, which also forms a so-called service hatch, is provided in a side wall of the receiving unit 4.

[0032] According to Fig. 1. A section of the tab pairs 4.1, 5.1 to 4.4, 5.4 is bent at 90°, and the bent section is then bent again at 90° so that a free end of each tab pair 4.1, 5.1 to 4.4, 5.4 rests more or less against an outer surface of the receiving unit 4. In particular, the tab pairs 4.1, 5.1 to 4.4, 5.4 are arranged according to a Fig. 3. The first version shown has been transformed.

[0033] Fig. Figure 4 shows a sectional view of a second embodiment of transformed tab pairs 4.1, 5.1 to 4.4, 5.4, wherein these are angled three times, so that a quadrilateral is formed by means of the tab pairs 4.1, 5.1 to 4.4, 5.4.

[0034] In Fig. Figure 5 shows a sectional view of a third embodiment of formed tab pairs 4.1, 5.1 to 4.4, 5.4, wherein the respective tab pair 4.1, 5.1 to 4.4, 5.4 is angled once by 90° and once by 45°, so that a free end of the respective tab pair 4.1, 5.1 to 4.4, 5.4 contacts a lower surface side of the tabs 4.1 to 4.4 of the receiving unit 4 along the vertical axis.

[0035] Fig. Figure 6 shows a sectional view of a fourth embodiment of formed tab pairs 4.1, 5.1 to 4.4, 5.4 of the housing 2, wherein the tab pairs 4.1, 5.1 to 4.4, 5.4 are formed such that an angled section has an arc shape.

[0036] It is also conceivable that one pair of tabs 4.1, 5.1 to 4.4, 5.4 or several pairs of tabs 4.1, 5.1 to 4.4, 5.4 is or are each transformed differently.

[0037] In Fig. Figure 7 shows a procedure for closing the housing 2 with a housing cover 5 in an alternative design.

[0038] In the alternative version, the housing cover 5 is also tub-shaped, but less deep than the receiving unit 4.

[0039] The housing cover 5 has further tabs 5.1 to 5.4 along its sides, which, when arranged on the receiving unit 4, form tab pairs 4.1, 5.1 to 4.4, 5.4 together with the tabs 4.1 to 4.4 of the receiving unit 4. The tab pairs 4.1, 5.1 to 4.4, 5.4 are formed according to the first embodiment, although any other forming is also possible.

[0040] The housing 2 of the electrical energy storage device 1 described above, regardless of its design, consists of two parts: the receiving unit 4 and the housing cover 5, which are sealed together by the adhesive 6. The housing 2 is stiffened by forming the respective pairs of tabs 4.1, 5.1 to 4.4, 5.4 and 4.1, 5.1 to 4.4, 5.4, thereby increasing protection, particularly in the event of a vehicle collision.

[0041] The pairs of tabs 4.1, 5.1 to 4.4, 5.4 can also form connection points for integrating the electrical energy storage device 1 into the vehicle, whereby the pairs of tabs 4.1, 5.1 to 4.4, 5.4 can serve as connection points for attaching the electrical energy storage device 1 to a vehicle body.

[0042] The cohesion of the housing 2 results from the material-bonded connection produced by means of the adhesive 6, whereby a form and force connection between the receiving unit 4 and the housing cover 5 is additionally produced by the respective forming. Reference symbol list 1 electrical energy storage device 2 cases 3-cell module 4 recording units 4.1 to 4.4 Tab 5 Housing covers 5.1 to 5.4 further tab 6 Adhesive 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 2010 030 993 A1

[0002]

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