Integrated contacting and spacer element for a battery module of a high-voltage battery of a motor vehicle, battery module, method for manufacturing a battery module and high-voltage battery

Abstract

An integrated contacting and spacer element (16) for a battery module (13) of a high-voltage battery of a motor vehicle, comprising: an electrically conductive cell contacting section (17) for electrically connecting two stacked battery cells (11, 12) of the battery module (13); and an elastically deformable spacer section (18) for accommodating a change in volume of the battery cells (11, 12), wherein the cell contacting section (17) and the spacer section (18) are mechanically connected to each other, and wherein the cell contacting section (17) can be arranged by placing the spacer section (18) between facing lateral surfaces (19, 20) of the stacked battery cells (11, 12) on respective cell terminals (14, 15) of the stacked battery cells (11, 12).

Description

[0001] The invention relates to an integrated contacting and spacer element for a battery module of a high-voltage battery for a motor vehicle. The invention also relates to a battery module, a method for manufacturing a battery module, and a high-voltage battery.

[0002] The present case focuses in particular on high-voltage batteries or high-voltage accumulators for electrically powered motor vehicles, such as electric or hybrid vehicles. Such high-voltage batteries comprise a multitude of battery cells, which can be stacked to form a cell block and interconnected to create a battery module. A cell contacting system (CCS), such as that known from DE 10 2014 219 178 A1, is typically used to electrically connect the battery cells. The cell contacting system shown therein has a support structure and several separate contact elements attached to the support structure. This support structure is usually arranged on the cell block so that the contact elements can be welded to the cell terminals of the battery cells to implement a predetermined interconnection of the battery cells.

[0003] A disadvantage of such a cell contacting system is that the support structure and the contact elements must be developed and manufactured separately, resulting in high costs. Furthermore, the support structure essentially only serves to position the contact elements during welding and is not needed again over the vehicle's lifetime. Therefore, the support structure increases the weight and space requirements of the high-voltage battery.

[0004] The object of the present invention is to provide a space-optimized, weight-optimized and cost-effective high-voltage battery for a motor vehicle, which is also easy to manufacture.

[0005] This problem is solved according to the invention by an integrated contacting and spacer element, a battery module, a method for manufacturing a battery module, and a high-voltage battery 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] An integrated contacting and spacer element according to the invention for a battery module of a high-voltage battery of a motor vehicle comprises an electrically conductive cell contacting section for electrically connecting two stacked battery cells of the battery module and an elastically deformable spacer section for accommodating volume changes of the battery cells. The cell contacting section and the spacer section are mechanically connected to each other. The cell contacting section can be positioned on the respective cell terminals of the stacked battery cells by arranging the spacer section between the facing lateral surfaces of the stacked battery cells.

[0007] The invention further relates to a battery module for a high-voltage battery of a motor vehicle comprising at least two stacked battery cells and at least one integrated contacting and spacer element according to the invention, or an embodiment thereof. The elastically deformable spacer section is arranged between the facing lateral surfaces of the at least two battery cells, and the electrically conductive cell contacting section for electrically connecting the battery cells is arranged on cell terminals of the battery cells.

[0008] In a method according to the invention for manufacturing such a battery module, at least two battery cells are stacked to form a cell block. Then, the at least one integrated contacting and spacer element is inserted between the two stacked battery cells via a top surface of the cell block that has the cell terminals of the battery cells, such that the spacer section is arranged between the outer surfaces of the battery cells and the cell contacting section rests on the cell terminals of the battery cells. Finally, the at least one cell contacting section is welded to the cell terminals.

[0009] The at least two battery cells or secondary cells are designed as prismatic cells, each with a flat, cuboid-shaped cell casing. The battery cells are stacked along a stacking direction to form a cell block by aligning the front surface of one battery cell's casing with the rear surface of another's casing, and so on. Each battery cell has two cell terminals on its upper surface. The first cell terminal forms, for example, the positive terminal of the battery cell, and the second cell terminal forms, for example, the negative terminal.

[0010] The integrated contacting and spacer element, or simply the integrated element, is designed for the electrical connection of the battery cells. The cell contacting section is positioned on the upper side of the cell block, which contains the cell terminals of the battery cells, such that it rests on a cell terminal of one battery cell and on a cell terminal of an adjacent battery cell. Which cell terminals are electrically connected depends on the desired configuration of the battery cells.

[0011] Secondly, the integrated element serves to space two adjacent, stacked battery cells apart, thus enabling volume changes in the battery cells along the stacking direction. For this purpose, the integrated element also includes a spacer section. Specifically, the integrated element consists of the spacer section and the cell contacting section, both of which are mechanically connected to form a single, integrated element. The spacer section is elastically deformable and is positioned between the lateral surfaces of two battery cells, i.e., between the front surface of one battery cell and the rear surface of the other. The spacer section accommodates or compensates for volume changes in the battery cells when they are stacked and clamped together in a cell module frame.Such a change in volume can be operational and may occur, for example, as a "bulging" of the battery cells during a charging process. When the battery cells bulge or expand along the stacking direction, the spacer section is reversibly compressed. This prevents the battery cells from being subjected to excessive pressure within the cell module frame due to the volume change and thus from being damaged.

[0012] The integrated element is formed as a single, monolithic unit. This means that the sections are mechanically connected before the integrated element is attached to the battery module, resulting in a single, complete component. The integrated element can be positioned on the battery module by, for example, sliding the spacer section between the battery cells until the cell contacting section rests on the cell terminals. The cell contacting section can then be welded to the cell terminals. The cell block, containing at least one integrated element, can be arranged in a cell module frame for clamping or pressing the battery cells along the stacking direction. Such a cell module frame can, for example, have two pressure plates arranged on opposite sides, which are pressed against each other by tie rods.

[0013] The integrated element, which functions as both an electrical contact element and a spacer, eliminates the need for a support structure typically used to position contact elements for welding onto the cell terminals. This allows for the creation of a particularly lightweight, cost-effective, and space-saving battery module. The one-piece, integrated element enables the battery cells to be electrically connected and spaced apart in just a few process steps.

[0014] The integrated contacting and spacer element may have a T-shaped cross-sectional area, at least in some areas, wherein the spacer section is oriented perpendicular to the stacking direction of the battery cells and the cell contacting section is oriented along the stacking direction of the battery cells. Preferably, the spacer section is planar and has dimensions corresponding to the height and width of the battery cells. The cell contacting section is strip-shaped and has dimensions corresponding to the width and spacing of the cell terminals.

[0015] The integrated element, with its T-shaped cross-section, is at least partially shaped like a joint strip. The flat or plate-shaped spacer section is oriented perpendicular to the stacking direction of the battery cells, along both a vertical and a horizontal direction. The stacking direction corresponds to a vertical direction of the battery cells. The spacer section has a height corresponding to the height of the battery cells and a width corresponding to the width of the battery cells. The flat spacer section thus completely overlaps the facing surfaces of the battery cells. This allows the outer edges of the spacer section to be flush with the battery cells. By arranging the spacer section flush with the battery cells, the strip-shaped cell contacting section is positioned on the cell terminals.In this process, one end of the strip-shaped cell contacting section is positioned on the cell terminal of one battery cell, and the other end is positioned on the cell terminal of the other battery cell. The precisely shaped integrated element allows for particularly accurate positioning of the cell contacting section on the cell terminals for the welding process.

[0016] It is advantageous if the cell contacting section is designed to be reversibly variable in length along a stacking direction of the battery cells. In particular, the cell contacting section has at least one arc-shaped area to achieve this reversible length variation. The arc-shaped area forms a compensating element of the cell contacting section, allowing its length to vary in response to changes in the volume of the battery cells, thus ensuring reliable contact between the battery cells during operation of the battery module. For example, the cell contacting section can have an omega profile.

[0017] According to one embodiment, the integrated contacting and spacer element is made of a hybrid material, wherein the spacer section comprises a first material and the cell contacting section a different second material. For example, the spacer section can be made of an elastomer or a flexible plastic. This allows the spacer section to also provide electrical insulation between the, for example, metallic, outer surfaces of the cell housings, thus eliminating the need for an electrically insulating coating on the outer surfaces. The cell contacting section can, for example, be a metallic contact plate. The sections can be mechanically joined together by hybrid joining to form the integrally connected element.

[0018] In another embodiment, the spacer section and the cell contacting section comprise the same material in different forms, wherein the material of the spacer section is formed as expanded metal and the material of the cell contacting section is formed as solid material. For example, the material is a metal, such as aluminum. To form the elastic spacer section, the material is formed as expanded metal, in particular expanded metal. The elastic spacer section can therefore, for example, have a metallic mesh, net, or grid. The cell contacting section, on the other hand, comprises solid material, which forms the cell contacting section in a plate-like, in particular sheet-like, form. In this case, it is advantageous if the facing surfaces of the cell housings are coated with an electrically insulating material.

[0019] A high-voltage battery according to the invention comprises at least one battery module according to the invention. The high-voltage battery can, for example, be a traction battery for an electrically powered motor vehicle.

[0020] The embodiments and advantages presented with reference to the integrated contacting and spacer element according to the invention apply accordingly to the battery module according to the invention, to the method according to the invention, and to the high-voltage battery according to the invention.

[0021] Further features of the invention will become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, are not only usable in the combinations specified, but also in other combinations or on their own.

[0022] The invention will now be explained in more detail with reference to a preferred embodiment and the drawings.

[0023] They show: Fig. 1 a schematic representation of a battery module according to the state of the art; Fig. 2 a schematic representation of an embodiment of a battery module according to the invention; and Fig. 3 a schematic representation of a further embodiment of a battery module according to the invention.

[0024] In the figures, identical and functionally equivalent elements are provided with the same reference symbols.

[0025] Fig. 1 shows two, along a stacking direction S stacked battery cells 1 , 2 a battery module 3 according to the state of the art in a side view. The battery cells 1 , 2 are known as prismatic battery cells 1 , 2 They are designed with flat, cuboid-shaped cell casings. Each battery cell has 1 , 2 two cell terminals, of which the first cell terminal is shown here. 4 a first battery cell and a second cell terminal 5 a second battery cell 2 are shown. The cell terminals 4 , 5are for the electrical interconnection of the battery cells 1 , 2 via a contact element 6 electrically connected. The contact element 6 can be, for example, a contact plate with an arc-shaped area 7 to enable movement of the cell terminals 4 , 5 along the stacking direction S be trained. The contact element 6 is here in a support structure 8 , for example, arranged and held in a plastic frame. For electrically connecting the battery cells 1 , 2 will the contact elements 6 by arranging the support structure 8 on a top side 9 the battery cells 1 , 2 on the cell terminals 4 , 5 The contact elements are positioned there. 6 with the cell terminals 4 , 5for electrically connecting the battery cells 1 , 2 welded. The supporting structure 8 Its main purpose is to position the contact elements. 6 on the cell terminals 4 , 5 and increases the weight, space requirements and costs of the battery module 3 .

[0026] Furthermore, the battery module 3 a spacer 10 on, which is between the battery cells 1 , 2 is arranged. The spacer 10 This could be, for example, an elastic mat that allows for a change in the volume of the battery cells. 1 , 2 , for example, an expansion or “bulging” of the battery cells 1 , 2 , enabled when the battery cells 1 , 2 are arranged in a cell module frame that is not shown here.

[0027] Fig. 2 and Fig. 3 show battery cells 11 , 12 an embodiment of a battery module according to the invention 13 For a high-voltage battery of an electrically powered vehicle (not shown here) in a side view. For electrically connecting cell terminals. 14 , 15 the battery cells 11 , 12 and to record the volume change of the battery cells 11 , 12 The battery module indicates 13 an integrated contacting and spacer element 16 on, which has a cell contacting section 17 as well as a distance holding section 18 exhibits. The cell contacting section 17 and the distance section 18 are mechanically connected or joined together, so that the integrated element 16 is formed in one piece. The cell contacting section 17It is designed to be electrically conductive and can, for example, be designed as a contact plate. The compensating section 18 is elastically deformable and located between facing lateral surfaces 19 , 20 the battery cells 11 , 12 arranged.

[0028] The distance-keeping section 18 points in a vertical direction H the battery cells 11 , 12 in particular a height 21 on, which at a height of the battery cells 11 , 12 This corresponds to the width of the battery cells. 11 , 12 (into the drawing plane) the spacing section 18 a width which corresponds to the width of the battery cells 11 , 12 corresponds to the one perpendicular to the stacking direction. S oriented distance section 18 It is therefore formed flat and can be flush with the battery cells11 , 12 to be arranged. The distance maintenance section overlaps in this process. 18 completely with the lateral surfaces 19 , 20 the battery cells 11 , 12 .

[0029] The cell contacting section 17 It is particularly strip-shaped, so that it connects with the cell terminals 14 , 15 Completely overlapping. The distance-maintaining section 18 and the cell contacting section 17 can, as in Fig. 2 shown, made of different materials and joined at a joint 22 They must be mechanically connected. The joint 22 This includes a peripheral area of ​​the flat buffer zone. 18 as well as an area of ​​the underside of the cell contacting section 17 The material of the spacer section 18For example, the cell contacting section material could be an elastomer, while the material of the cell contacting section could be a metal. The integrated element 16 is therefore made of a hybrid material. However, it can also be provided that the distance-keeping section 18 and the cell contacting section 17 , as in Fig. 3 shown, are made from the same material, with the materials used to provide the desired property for each section. 17 , 18 They are shaped differently. The material of the spacer section 18 It can, for example, be designed as an elastically deformable stretchable material. The material of the cell contacting section 17 can be formed from a solid material. The stretch material can be, for example, a wire fiber braid or the like. The solid material can be, for example, a metal sheet. The cell contacting section 17This in turn can create arc-shaped areas 23 to prevent loss of contact when the volume of the battery cells changes 11 , 12 and thus during movement of the cell terminals 14 , 15 exhibit.

[0030] The one-piece integrated element 16 is connected to the distance holding section 18 from above against the upward direction H between the battery cells 11 , 12 inserted so that the distance-keeping section 18 with the lateral surfaces 19 , 20 overlaps and the cell contacting section 17 on the cell terminals 14 , 15 rests on. This positioning of the cell contacting section. 17 This is done without a supporting structure. As soon as the distance maintenance section 18 between the battery cells 11 , 12 is introduced and the cell contacting section 17 on the cell terminals14 , 15 resting, the cell contacting section 17 with the cell terminals 14 , 15 The battery cells are welded together. The contacted and spaced-apart battery cells are then connected. 11 , 12 They can then be arranged in a tensioned cell module frame. Reference symbol list 1, 2 battery cells 3 battery modules 4.5 cell terminals 6 Contact element 7 arc-shaped area 8 Support structure 9 Top 10 spacers 12, 12 battery cells 13 Battery module 14, 15 cell terminals 16 integrated contacting and spacer element 17 Cell contacting section 18 Distance section 19, 20 lateral surfaces 21 Height 22 joint 23 arc-shaped area S Stacking direction H Upward 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 102014219178 A1

[0002]

Claims

[1] Having an integrated contacting and spacer element (16) for a battery module (13) of a high-voltage battery of a motor vehicle - an electrically conductive cell contacting section (17) for electrically connecting two stacked battery cells (11, 12) of the battery module (13), and - an elastically deformable spacer section (18) for accommodating a volume change of the battery cells (11, 12), wherein the cell contacting section (17) and the spacer section (18) are mechanically connected to each other and wherein the cell contacting section (17) can be arranged by arranging the spacer section (17) between mutually facing lateral surfaces (19, 20) of the stacked battery cells (11, 12) on respective cell terminals (14, 15) of the stacked battery cells (11, 12). [2] Integrated contacting and spacer element (16) according to claim 1, characterized by, that the integrated contacting and spacer element (16) has at least in some areas a T-shaped cross-sectional area, wherein the spacer section (18) is oriented perpendicular to a stacking direction (S) of the battery cells (11, 12) and the cell contacting section (17) is oriented along the stacking direction (S) of the battery cells (11, 12). [3] Integrated contacting and spacer element (16) according to claim 1 or 2, characterized by , that the spacer section (18) is planar and has dimensions corresponding to the height and width of the battery cells (11, 12) and the cell contacting section (17) is strip-shaped and has dimensions corresponding to the width and spacing of the cell terminals (15, 15). [4] Integrated contacting and spacer element (16) according to one of the preceding claims, characterized by, that the cell contacting section (17) is designed to be reversibly variable in length along a stacking direction (S) of the battery cells (11, 12). [5] Integrated contacting and spacer element (16) according to claim 4, characterized by , that the cell contacting section (17) has at least one arc-shaped area (23) to form the reversible length variability. [6] Integrated contacting and spacer element (16) according to one of the preceding claims, characterized by , that the integrated contacting and spacer element (16) is formed from a hybrid material, wherein the spacer section (18) has a first material and the cell contacting section (17) has a different second material. [7] Integrated contacting and spacer element (16) according to one of the preceding claims, characterized by, that the spacer section (18) and the cell contacting section (17) have the same material in different forms, wherein the material of the spacer section (18) is formed in the form of stretched material and the material of the cell contacting section (17) is formed in the form of solid material. [8] Battery module (13) for a high-voltage battery of a motor vehicle comprising at least two stacked battery cells (11, 12) and at least one integrated contacting and spacer element (16) according to one of the preceding claims, wherein the elastically deformable spacer section (18) is arranged between mutually facing cladding surfaces (19, 20) of the at least two battery cells (11, 12) and the electrically conductive cell contacting section (17) for electrically connecting the battery cells (11, 12) is arranged on cell terminals (14, 15) of the battery cells (11, 12). [9] Method for manufacturing a battery module (13) according to claim 8, comprising the steps: - Stacking at least two battery cells (11, 12) to form a cell block, - Inserting at least one integrated contacting and spacer element (16) between the two stacked battery cells (11, 12) via a top side of the cell block having the cell terminals (14, 15) such that the spacer section (18) is arranged between the cladding surfaces (19, 20) of the battery cells (11, 12) and the cell contacting section (17) rests on the cell terminals (14, 15) of the battery cells (11, 12), and - Welding of at least one cell contacting section (17) to the cell terminals (14, 15). [10] High-voltage battery for an electrically powered motor vehicle comprising at least one battery module (13) according to claim 8.

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