Battery module for a high-voltage battery of a motor vehicle, high-voltage battery and motor vehicle

Abstract

Battery module (1) for a high-voltage battery of a motor vehicle with at least two battery cells (2), with two pressure plates (17, 18) between which the battery cells (2) are arranged, and with at least two tension anchors (19, 20) which are guided along opposite side regions (9, 10) of the at least two battery cells (2), which are connected to the pressure plates (17, 18) to form a cell module frame surrounding the battery cells (2) and pressing the battery cells (2) together, and which are bonded to the respective side regions (9, 10) of the battery cells (2) by means of an adhesive bond (21), wherein the battery cells (2) have a metallic cell housing (4) which is coated at least partially with an electrically insulating lacquer (23), characterized in thatthat only a U-shaped area (24) of a rectangular front (5) and / or back (6) of the respective cell housings (2) is coated with the lacquer (23), wherein the U-shaped area (24) is formed by edge areas of the front (5) and / or back (6) adjacent to the edges of the rectangular front (5) and / or back (6).

Description

[0001] The invention relates to a battery module for a high-voltage battery of a motor vehicle, comprising at least two battery cells, two pressure plates between which the battery cells are arranged, and at least two tie rods which are guided along opposite side regions of the at least two battery cells and which are connected to the pressure plates to form a cell module frame surrounding the battery cells and pressing the battery cells together. The invention further relates to a high-voltage battery for a motor vehicle and to a motor vehicle.

[0002] The present case concerns high-voltage batteries, which, for example, serve to supply energy to an electric drive motor in a motor vehicle designed as an electric or hybrid vehicle. Such high-voltage batteries typically comprise a large number of prismatic battery cells connected to form battery modules or cell packs. During the manufacture of the battery module, the battery cells are usually pressed together under controlled displacement and force monitoring, and clamped and held in shape by a surrounding cell module frame. Such a cell module frame can, for example, be an aluminum frame formed from two pressure plates and at least two tie rods, as described, for example, in DE 10 2014 219 353 A1. The prismatic battery cells are arranged between the pressure plates and pressed together.Tension anchors are attached to the pressure plates to connect them and maintain the compressed state. High-voltage insulation between the battery cells and the aluminum frame is achieved, for example, through additional plastic insulating jackets. Low-voltage insulation between the individual battery cells can be implemented, for example, using adhesive plastic films.

[0003] Such an arrangement of battery cells typically generates heat, which must be dissipated to prevent the battery module from overheating. For this purpose, a cooling device can be provided below the battery module to cool the battery cells. High-voltage electrical insulation is also necessary between the battery module and the cooling device, which can be achieved, for example, with an additional plastic film. From DE 10 2015 205 481 A1, it is known to coat at least that outer surface of a metallic cell housing of the battery cells, which faces the cooling device, with a UV-curable lacquer. This lacquer, which eliminates the need for the plastic film, also ensures high thermal conductivity between the battery module and the cooling device, thus guaranteeing reliable heat dissipation.

[0004] The object of the present invention is to provide a battery module optimized with regard to mechanical stability and electrical insulation for a high-voltage battery of a motor vehicle.

[0005] This problem is solved according to the invention by a battery module, a high-voltage battery, and a motor vehicle with the features according to the respective independent claims. Advantageous embodiments of the invention are the subject of the dependent claims, the description, and the figures.

[0006] A battery module according to the invention for a high-voltage battery of a motor vehicle comprises at least two battery cells, two pressure plates between which the battery cells are arranged, and at least two tension anchors which are guided along opposite side regions of the at least two battery cells and which are connected to the pressure plates to form a cell module frame surrounding the battery cells and pressing the battery cells together. Furthermore, the tension anchors are bonded to the respective side regions of the battery cells by means of an adhesive bond.

[0007] A high-voltage battery is primarily a traction battery used to provide electrical energy for an electrically powered vehicle. It can consist of several interconnected battery modules. Each battery module contains, in particular, a multitude of battery cells connected, for example, in series. The battery cells are typically prismatic cells with a flat, cuboid-shaped housing.

[0008] The battery cell casing has a bottom, a top, a front, a back, and two side sections. Forming a cuboid cell stack, the front of one battery cell casing is positioned against the back of the casing of another battery cell. The battery cells are thus stacked or arranged in a row, with the front of the cell stack being formed by the front of the casing of the first battery cell in the stack and the back of the cell stack being formed by the back of the casing of the last battery cell in the stack.The side surfaces of the cell casings of the stacked battery cells form opposing sides of the cell stack, the top surfaces of the cell casings of the stacked battery cells form a top surface of the cell stack, and the bottom surfaces of the cell casings of the stacked battery cells form a bottom surface of the cell stack. The battery cells have, in particular, a cell terminal pair on the top surface of each cell casing, consisting of a positive cell terminal and a negative cell terminal. The battery cells can be interconnected via a cell contacting system, which is, for example, mounted on the top surface of the cell stack and which includes electrical connecting elements for connecting the cell terminals of adjacent battery cells.

[0009] A first pressure plate is positioned on the front of the cell stack, and a second pressure plate is positioned on the opposite rear side of the cell stack. The pressure plates are pressed together, compressing the battery cells. The pressure plates that compress the battery cells are connected to each other via the respective tension rods, ensuring that the battery cells remain compressed and that the cell stack retains its shape. The tension rods are also bonded to the opposing sides of the cell stack, creating a form-fit connection. Specifically, the adhesive bond for this material-bonded connection comprises a polyurethane adhesive and / or an epoxy adhesive and / or an acrylic adhesive.The mechanical stabilization of the battery module provided by the cell module frame is advantageously further enhanced by additionally bonding the tension anchors to the cell stack. The cell module frame, which is at least partially bonded, thus advantageously prevents deformation of the battery cell casings during operation of the high-voltage battery.

[0010] Preferably, the pressure plates are also bonded to the adjacent battery cell by means of an adhesive bond. The first pressure plate is thus bonded to the front of the cell stack, and the second pressure plate is bonded to the back of the cell stack. Connection points between the pressure plates and the tension anchors, i.e., corners of the rectangular cell module frame, are welded and / or bonded, for example. By bonding the entire cell module frame to the cell stack via the adhesive bond, a mechanically particularly stable battery module can be provided.

[0011] The battery cells can be designed with a metallic cell housing that is coated, at least partially, with an electrically insulating lacquer. This electrically insulating lacquer is, in particular, a UV-curable lacquer. The electrically insulating lacquer allows the metallic cell housing to be insulated, enabling, for example, adjacent battery cells in the cell stack, battery cells and pressure plates, and battery cells and tie rods to be arranged directly next to each other without the need for any additional physical insulating element. This results in a particularly lightweight and space-optimized battery module.

[0012] It proves advantageous if at least the undersides of the battery cells are completely coated with the lacquer for connection to a metallic cooler. In particular, the undersides are bonded to the metallic cooler for cooling the battery module via an additional adhesive bond, wherein this additional adhesive bond for thermal coupling between the battery module and the cooler comprises a thermally conductive material. The cooler can be made of a highly thermally conductive metallic material, such as aluminum. The underside of the cell stack is coated with the electrically insulating lacquer, allowing the cell stack to be connected directly to the cooler without the need for an additional insulating element between the cell stack and the cooler.The paint and the additional thermally conductive adhesive bond between the paint and the cooler result in particularly high thermal conductivity, so that the waste heat generated during the operation of the battery cells can be reliably transferred to the cooler.

[0013] Particularly preferred is a U-shaped area of ​​a rectangular front and / or back of the respective cell housings coated with the lacquer, wherein the U-shaped area is formed by edge regions of the front and / or back that adjoin the edges of the rectangular top surface. The lacquer is thus applied only to certain areas of the front and / or back of the cell housings. Specifically, the edge region of two short sides of the front and / or back that adjoin the side regions of the cell housings, as well as an edge region of a long side of the front and / or back that adjoins the underside of the cell housings, is coated with the lacquer. An edge region of a long side of the front and / or back that adjoins the top surface of the cell housings is not coated with the lacquer, at least in part.The coating on the underside and sides of the battery cell casings extends partially beyond the edge, thus running off onto the front and / or back. If both the front and back are coated in the U-shaped area, an electrically insulating film, such as a self-adhesive plastic film, can be placed between the front of one battery cell and the back of an adjacent one. Alternatively, only the front surfaces of the cell casings in the U-shaped area may be coated, while the back surfaces are fully coated. This eliminates the need for a physical insulating element between the battery cells when they are connected in series, where the partially coated front surface meets a fully coated back surface.This can advantageously reduce manufacturing, assembly and material costs.

[0014] The invention further relates to a high-voltage battery for a motor vehicle comprising at least one battery module or embodiment thereof according to the invention. The high-voltage battery is, in particular, a traction battery for providing electrical energy for an electric drive of the motor vehicle.

[0015] A motor vehicle according to the invention comprises a high-voltage battery according to the invention. The motor vehicle is in particular designed as an electric vehicle or hybrid vehicle.

[0016] The embodiments and advantages presented with reference to the battery module according to the invention apply accordingly to the high-voltage battery according to the invention and to the motor vehicle according to the invention.

[0017] Further features of the invention will become apparent from the claims, the figure, and the figure description. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and / or shown in the figure alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0018] The invention will now be explained in more detail with reference to a preferred embodiment and the drawing.

[0019] The single figure shows a schematic exploded view of an embodiment of a battery module according to the invention.

[0020] The figure shows a battery module. 1for a high-voltage battery (not shown here) of a motor vehicle (also not shown here). The high-voltage battery can, for example, provide electrical energy to power the motor vehicle, which is designed as an electric or hybrid vehicle. The battery module 1 features a variety of battery cells 2 on, which form a cell stack 3 stacked next to each other or arranged in a row. Each battery cell 2 It has a flat, cuboid-shaped, metallic cell casing 4 with a front side 5 , a reverse side 6 , an upper side 7 , a subpage 8 and two opposing side areas 9 , 10 up. To form the cell stack 3 Each front side will be 5 of the cell casing 4 a battery cell 2 on the back 6 of the cell casing4 another battery cell 2 arranged. The front 5 of the cell casing 4 a first battery cell 2 in the cell stack 3 forms a front side 11 of the cell stack 3 and the back 6 of the cell casing 4 one last battery cell 2 in the cell stack 3 forms a reverse side 12 of the cell stack 3 The tops 7 the cell casing 4 form a top 13 of the cell stack 3 and the subpages 8 the cell casing 4 form a subside 14 of the cell stack 3 . First page areas 9 the cell casing 4 form a first side area 15 of the cell stack 3 and second page areas 10 form one of the first page areas 15opposite second side area 16 of the cell stack 3 .

[0021] Furthermore, the battery module 1 a first, front-facing pressure plate 17 on, which are on the front 11 of the cell stack 3 is arranged, and a second, rear pressure plate 18 on, which is on the back 12 of the cell stack 3 is arranged. The printing plates 17 , 18 are compressed together and secured via tie rods 19 , 20 interconnected. For example, the printing plates 17 , 18 and the tie rods 19 , 20 They are glued or welded at their respective connection points. The printing plates 17 , 18 and the tie rods 19 , 20 They form a cell module frame through which the battery cells 2 are pressed together and the cell stack3 is kept in shape. A first tie rod 19 This is done via an adhesive bond 21 materially bonded to the first side area 15 of the cell stack 3 connected and a second tie rod 20 is via the adhesive bond 21 materially bonded to the second side area 16 of the cell stack 3 connected by the adhesive bonds 21 between the tie rods 19 , 20 and the cell stack 3 The battery module indicates 1 They exhibit particularly high mechanical stability. The printing plates can also... 17 , 18 by means of an adhesive bond to the front 11 and the reverse 12 of the cell stack 3 The entire cell module frame is thus connected by means of the adhesive bond. 21 with the cell stack 3 form-fitting connection. The adhesive bond 21It may contain an epoxy adhesive, a polyurethane adhesive, or an acrylic adhesive.

[0022] The battery module 1 It also features a cooler 22 on, which is used to cool the cell stack 3 is designed for this purpose. The cooler is used for this. 22 on the underside 14 of the cell stack 3 arranged. The cooler 22 It features, in particular, a metallic material with good thermal conductivity, such as aluminum. For electrical insulation between the cooler 22 and the battery cells 2 at least the underside 8 the cell casing 4 with an electrically insulating, UV-curable lacquer 23 coated. Due to the coating 23 The provided insulation can be applied to further physical insulation components between the cell stack. 3 and the cooler 22 This can be dispensed with. For attaching the cooler22 at the cell stack 3 can the underside 15 of the cell stack 3 and the cooler 22 They are bonded together via a further, thermally conductive adhesive bond.

[0023] The paint 23 can be done on the front sides 5 and / or the reverse sides 6 the cell casing 4 in a U-shaped area 24 be arranged. In this case, both the front sides are 5 as well as the reverse sides 6 the cell casing 4 the battery cells 2 only in the U-shaped area 24 with the paint 23 coated. To create electrical insulation, a layer is applied between adjacent battery cells. 2 as between the battery cells 2 and the respective printing plates 17 , 18 each an insulating layer 25, for example, an insulating plastic film which is attached via adhesive strips 26 with the cell casings 4 or the printing plates 17 , 18 is connected, arranged. However, it is also possible that only the front side is connected. 5 the cell casing 4 in the U-shaped area 24 with lacquer 23 are coated, while the reverse sides are 6 completely with the paint 23 are coated. In this case, the insulating layer 25 between the battery cells 2 omitted.

[0024] On the top 7 the battery cells 2 respective cell connections 27 , 28 For connecting the battery cells in series. 2 Each will have a first cell connection 27 , for example, a positive cell terminal of a battery cell 2 with a second cell connection 28, for example a negative cell terminal, a previous battery cell 2 in the cell stack 3 electrically connected. A cell contacting system can be used to establish the electrical connection. 29 on the top 13 of the cell stack 3 to be set, which has electrical connecting elements. On the cell contacting system 29 can a cover element 30 to cover the battery module 1 be set. Reference symbol list 1 battery module 2 battery cells 3 cell stacks 4 cell casings 5 Front of the cell casing 6 Back of the cell casing 7 Top of the cell casing 8 Underside of the cell casing 9 first side area of ​​the cell casing 10 second side area of ​​the cell casing 11 Front side of the cell stack 12 Back of the cell stack 13 Top of the cell stack 14 Underside of the cell stack 15 first side area of ​​the cell stack 16 second side area of ​​the cell stack 17 first printing plate 18 second printing plate 19 first tie rod 20 second tie rod 21 Adhesive bond 22 coolers 23 Lacquer 24 U-shaped area 25 Insulation layer 26 adhesive strips 27 first cell connection 28 second cell connection 29 Cell contacting system 30 cover element 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 102014219353 A1

[0002] DE 102015205481 A1

[0003]

Claims

[1] Battery module (1) for a high-voltage battery of a motor vehicle comprising at least two battery cells (2), comprising two pressure plates (17, 18) between which the battery cells (2) are arranged, and comprising at least two tie rods (19, 20) which are guided along opposite side regions (9, 10) of the at least two battery cells (2) and which are connected to the pressure plates (17, 18) forming a cell module frame surrounding the battery cells (2) and pressing the battery cells (2) together, characterized by , that the tie rods (19, 20) are bonded to the respective side areas (9, 10) of the battery cells (2) by means of an adhesive bond (21). [2] Battery module (1) according to claim 1, characterized by , that in addition the printing plates (17, 18) are materially connected to the battery cell (2) adjacent to the respective printing plate (17, 18) by means of the adhesive connection (21). [3] Battery module (1) according to claim 1 or 2, characterized by , that the adhesive bond (21) comprises a polyurethane adhesive and / or an epoxy adhesive and / or an acrylic adhesive. [4] Battery module (1) according to any one of the preceding claims, characterized by , that the battery cells (2) have a metallic cell housing (4) which is coated at least partially with an electrically insulating varnish (23). [5] Battery module (1) according to claim 4, characterized by , that at least the undersides (8) of the battery cells (2) for connecting the undersides (8) to a metallic cooler (22) are completely coated with the paint (23). [6] Battery module (1) according to claim 5, characterized by, that the undersides (8) are bonded to the metallic cooler for cooling the battery module (1) via a further adhesive bond, wherein the further adhesive bond for thermal coupling between the battery module (1) and the cooler comprises a thermally conductive material. [7] Battery module (1) according to any one of claims 4 to 6, characterized by , that a U-shaped area (24) of a rectangular front (5) and / or back (6) of the respective cell housings (2) is coated with the lacquer (23), wherein the U-shaped area (24) is formed by edge areas of the front (5) and / or back (6) adjacent to edges of the rectangular front (5) and / or back (6). [8] High-voltage battery for a motor vehicle comprising at least one battery module (1) according to any of the preceding claims. [9] Motor vehicle with a high-voltage battery according to claim 8.

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