DE102024107708B3 - Battery case with adapter - Google Patents

Abstract

The present invention relates to a battery housing (10) for accommodating battery modules (24) comprising a plurality of battery cells, comprising at least two adapters (20, 22) for supporting at least one battery module (24), wherein the adapters (20, 22) are fastened by means of screws (26) in receptacles arranged on opposite inner wall surfaces (14) of the housing (10), wherein the respective screw axis of the screws (26) is inclined to the vertical, which corresponds to a stacking direction.

Description

Technical area

The present invention relates to a battery housing for battery modules, in particular for providing a stackable arrangement of battery modules within a battery housing.

State of the art

Batteries are used in particular as high-voltage batteries or traction batteries, for example to provide electrical energy in an electric vehicle (EV). The batteries typically comprise several battery modules, with each battery module containing a large number of battery cells, for example in the form of pouch cells, prismatic cells or cylindrical cells. In other words, battery modules form a type of subassembly that structures or specifies the production and assembly of the battery. The number of battery modules that can be arranged within the battery is typically limited to the dimensions of the housing. A particular challenge that arises here is the use of the existing height within the battery housing to form a battery.

Arranging battery modules one above the other, in multiple layers, or in multiple levels has proven to be a challenge. Such an arrangement can be advantageous when the available installation space is several times higher than the individual battery cell or battery module in its specified orientation.

Multi-layer or multi-layered arrangements are known from the prior art. However, these are typically only two-layered. To enable the two-layer arrangement, for example, an intermediate base can be provided for mounting the upper layer, or alternatively, a layer can be arranged above the housing cover. Alternatively, two-layer battery modules can be used, which are separated from each other, for example, by an intermediate cooling plate. However, these designs require a complex internal structure of the battery housing, which is associated with high material expenditure. Furthermore, such configurations require a large number of assembly steps, and assembly is complex due to the predetermined internal structure. The overall costs, the internal structure, and also the overall weight can significantly limit the respective application, so that usually no more than two battery module layers can be implemented.

Accordingly, there is a need to provide a battery housing which enables a simpler and/or improved mechanical fastening of battery modules in the housing and in particular a multi-layer arrangement.

Out of US 2021/0066688 A1 an arrangement of an energy storage device is known, which is designed as a stack and in which adapters are provided for fastening. Furthermore, JP 2001-097 049 A a battery housing for an electric vehicle is known, wherein rails are provided for holding a battery.

Description of the invention

Based on the known prior art, it is an object of the present invention to provide a correspondingly improved battery housing. In particular, one object can be seen in enabling a multi-layer arrangement of battery modules within a battery housing with simplified assembly.

The object is achieved by a battery housing having the features of claim 1 and claim 2. Advantageous further developments emerge from the subclaims, the description and the figures.

Accordingly, a battery housing for accommodating battery modules, each comprising a plurality of battery cells, is proposed, comprising at least two adapters for supporting at least one of the battery modules, wherein the adapters are fastened by means of screws in receptacles provided on opposing inner wall surfaces of the housing, and wherein the respective screw axis of the screws in the respective receptacle is inclined to the vertical, which corresponds to a stacking direction. According to the invention, the battery housing is designed for at least two battery module layers stacked one above the other. Each battery module layer comprises at least one battery module, wherein the at least one battery module of the lowest battery module layer is screwed directly to the battery housing, and each battery module of a battery module layer arranged above the lowest battery module layer is fastened to the housing by means of adapters. Alternatively or in addition to the fastening of the battery modules in the battery module layers, it is provided that at least two inner wall surfaces, which have at least some of the predetermined receptacles, are inclined to the vertical such that a width an inner cavity of the battery housing widens in the stacking direction.

Because the screw axes are screwed into the receptacles at an angle to the vertical, a particularly space-saving fastening in a direction perpendicular to the stacking direction and away from the respective inner wall surface is ensured. Accordingly, the available installation space—that is, an internal cavity defined by the housing—can be used very efficiently for the battery modules, allowing the battery modules to each contain a larger number of battery cells, and the resulting battery to have a higher energy density.

While the vertical corresponds to the stacking direction and can define a height of the battery housing, the horizontal correspondingly defines a horizontal plane which extends perpendicular to the vertical. Accordingly, because the screw axes are screwed into the receptacles at an angle to the vertical, an increased free space is provided in a specific horizontal direction which leads away from the inner wall surface. The extension of the housing is to be understood such that the housing has a height in the vertical direction, a length in a first horizontal direction and a width in a second horizontal direction, wherein the height, width and length are orthogonal to one another. Accordingly, the housing provides a defined internal volume or defines an internal cavity.

Furthermore, the inclined arrangement and screw connection ensures that the screws are easily accessible and can be tightened with a screwdriver from the top of the housing, thus significantly simplifying the assembly of the adapters and battery modules and, if necessary, enabling automation. In other words, this enables improved industrial production.

Thanks to the adapters, a full-surface intermediate plate or even a complex frame-like internal structure with corresponding brackets and supports for a multi-layer arrangement of the battery modules can be eliminated. This not only simplifies the assembly of the battery itself, but also significantly reduces the resulting weight of the battery housing, while simultaneously reducing material requirements and the associated costs.

The adapters also allow the modularity of the battery modules to be maintained, especially since multiple battery modules can be easily stacked and attached to the housing using the adapters and the predefined mounts. Accordingly, the height of the battery housing can be easily adjusted to the dimensions, height, and number of the intended battery modules. This eliminates the need for multiple separate batteries (with their respective battery housings) stacked on top of each other, nor does the number of battery cell layers within a battery module need to be adjusted to the intended energy density of the battery.

The battery housing can, in particular, have four side walls and a base plate, which are preferably firmly connected to one another. In the stacking direction, a housing cover can be provided above the uppermost battery module, i.e., the battery module furthest from a base plate. For example, when the battery is mounted, the housing cover is arranged on the chassis side or is adjacent to the chassis of an electric vehicle and/or is connected to it. Alternatively, it can also be provided that the top side of the housing is directly connected to a chassis, so that a housing cover can optionally be omitted.

As stated, the vertical essentially corresponds to a stacking direction. Preferably, the vertical corresponds to a direction that runs perpendicular to a base plate. Accordingly, battery modules can be stacked one on top of the other in a gravitational field. Battery modules can also be arranged horizontally next to one another, so that the battery housing can have at least two battery module layers stacked one on top of the other, with each battery module layer comprising at least two or exactly two battery modules stacked next to one another. Designs adapted to the respective specified form factor are possible.

The inner wall surfaces, which have the predefined receptacles for the adapters, face each other. The receptacles can essentially be provided as drilled holes in the housing wall, with the receptacles or the housing wall section and the drilled holes being designed and aligned accordingly to ensure the inclination of the screw axis to the vertical.

The inclination of the respective screw axis is preferably in the range between 10 degrees and 50 degrees. A particularly advantageous angle range is between 20 degrees and 40 degrees. This allows for improved attachment of the respective adapter and the corresponding battery module to the housing wall. It also provides a particularly space-saving attachment and improved accessibility for screwing.

The dimensions and, in particular, the height of the battery housing can be selected virtually arbitrarily due to the provided receptacles and adapters. Accordingly, the battery housing is designed for at least two battery module layers stacked one above the other, or for three or more battery module layers stacked one above the other, with each battery module layer comprising at least one battery module or at least two battery modules arranged side by side.

As explained above, a two-layer arrangement is only possible in the prior art in combination with a complex, frame-like internal structure and intermediate plate. However, the adapters and the predefined mounts enable an almost completely modular design, whereby, in particular, three battery module layers can be provided within the battery housing without requiring a complex mounting structure or resulting in a significant increase in overall weight.

At least one battery module of the lowest battery module layer is screwed directly to the battery housing. Each battery module of a battery module layer arranged above the lowest battery module layer is attached to the housing using adapters.

In other words, an adapter for the bottom or lowest battery module layer can optionally be omitted, and corresponding receptacles for direct screw connection can be provided on the lowest housing section. For each battery module layer above, corresponding adapters are screwed to the housing wall. Accordingly, both the inner wall surface for fastening and the installation space or an inner cavity of the housing can be optimally utilized for the battery modules, especially since the adapters can be successively attached to the inner wall surface for each battery module layer in the stacking direction.

Each adapter and/or each receptacle for each stacked battery module layer can be of identical design and/or can have the same extension in the horizontal direction. For example, each adapter can have the same extension in a horizontal direction along the inner wall surface and/or in a horizontal direction that extends in a direction perpendicular to the stacking direction and away from the respective inner wall surface. This can further simplify assembly. In the case of different distances between the inner wall surfaces for different heights of the battery housing, it can be provided that the battery module size is different for the respective stacked battery module layer.

Alternatively, however, it can also be provided that a correspondingly designed adapter is provided for a predetermined height of receptacles in the battery housing in the stacking direction, wherein adapters for different predetermined heights can in particular have a different extension in the horizontal direction, i.e. in a direction substantially perpendicular to the stacking direction and preferably in a direction leading away from the respective inner wall surface. For example, one adapter can have a longer extension in the direction of the facing and opposite inner wall surface compared to another adapter. This makes it possible, in particular, to take into account a horizontal widening of the inner cavity in the stacking direction and to bridge any gap that might otherwise occur between the adapter and a support of the respective battery module.

At least one adapter can be designed as an adapter strip which extends along a respective inner wall surface substantially perpendicular to the stacking direction and has a plurality of fastening means for fastening a respective battery module or several battery modules arranged next to one another. The adapter strip can accordingly provide a continuous storage surface for the battery module or for several battery modules. The adapter strip can be designed for a respective battery module, wherein the plurality of fastening means enables secure and stable fastening of the battery module at several points on the housing. The extension of the adapter strip can in particular take place in a longitudinal direction which is defined by a longer side wall of the housing and/or a stacking direction of battery cells within the respective battery module.

Alternatively, or additionally, at least two adapters may each have a single fastening means for securing a battery module and may be spaced apart along a respective inner wall surface substantially perpendicular to the stacking direction. Thus, for a relatively small battery module, two adapters may be arranged side by side. For example, two adapters are also attached to the corresponding inner wall surface on the opposite inner wall surface to support and secure the battery module evenly. However, at least one adapter in the form of an adapter strip can also be provided on an inner wall surface. Furthermore, for larger battery modules, more than two adapters can be arranged in series to enable improved weight and load distribution and improved attachment to the housing wall.

The fastening means can have a bearing surface that extends substantially perpendicular to the stacking direction, and wherein the bearing surface has at least one bore with an internal thread for receiving a fastening screw of the respective battery module. The bearing surface can, for example, extend both along the inner wall surface and in the direction of the opposite inner wall surface. In particular, the bearing surface can be adapted to the bore and a corresponding dimensioning of a support surface.

The fastener can have only a hole. The hole itself can have an internal thread, or a sleeve with an internal thread can be inserted into the hole and firmly connected to the adapter.

In a further advantageous embodiment according to the invention, the battery housing can comprise at least four side walls defining an inner cavity of the housing. The battery housing can be formed from multiple parts. Preferably, the housing or the core housing is formed from a single part. The battery housing can also comprise a base plate, which is preferably also formed integrally with the housing.

The one-piece design allows for simplified assembly and thus also achieves improved mechanical robustness. In particular, the battery housing can be designed as a cast part. In this way, a one-piece casting core can be provided, which can further improve mechanical robustness. Because the adapters eliminate the need for a complex, frame-like internal structure, which would impair a casting process, the battery housing enables a design that is more suitable for casting without material accumulation. In other words, there are no other support surfaces or holders inside the housing, which usually extend perpendicular to the inner wall surface into the inner cavity of the housing, which would make a casting process impossible. Instead, the invention provides adapters that can simply be screwed into the housing wall or into the cast part. Alternatively, the one-piece design can also be provided by a welded construction, for example, wherein multi-part profiles are welded together.

In this respect, the inclination of the screw connection of the adapters and the corresponding design of the predefined receptacles are also particularly advantageous, especially since these also allow accessibility to an internal cavity or the casting core, so that the cast housing can be advantageously processed, for example for milling work or for providing threaded points in the housing.

At least two inner wall surfaces, which have at least some of the predetermined receptacles, are inclined to the vertical, in particular outwards. Due to the inclination, in particular a width of an inner cavity of the battery housing widens in the stacking direction. In other words, at least the opposing inner wall surfaces with the predetermined receptacles can be inclined outwards, so that a distance between the inner wall surfaces at least partially increases in the stacking direction or a width between the inner wall surfaces widens at least partially and/or stepwise in the stacking direction. The inner wall surfaces thus extend away from the inner cavity of the housing in the stacking direction.

Such a design not only supports the inclination of the screw connections for the adapters, but is also advantageous for the production of the battery housing as a single cast part. The inclination of the inner wall surfaces can be designed, in particular, as a draft angle.

The inclination of the inner wall surfaces is preferably in the range between 0.5 degrees and 5 degrees, particularly preferably between 1 degree and 4 degrees. Relative to the vertical, the inclination is thus slight, but large enough to simplify the assembly of the adapters and/or to enable the battery housing to be designed as a single component in the form of a cast part.

Although a single battery module can be provided in each battery module layer, the battery housing can also be designed for a plurality of battery modules in each battery module layer. This can, for example, reduce the dimensions of the individual battery modules and thus facilitate handling. Furthermore, such configurations can be advantageous with regard to on the cooling, control and/or fire safety of the battery and/or ensure that in the event of a battery module failure the energy supplied is not significantly reduced.

Accordingly, the battery housing can comprise at least one intermediate wall arranged between the inner wall surfaces, which have at least some of the predefined receptacles, and which defines separate receiving spaces for accommodating battery modules arranged side by side. At least one adapter is fastened to each of the intermediate wall surfaces by means of screws, with the respective screw axis of the screws being inclined relative to the vertical. The at least one intermediate wall can be mounted as a separate part in the housing or formed integrally with the housing.

The at least one partition wall allows a construction space or receiving space for the battery modules, which can correspond to an internal cavity of the battery housing, to be divided into different chambers or sections, which can be either of equal or different dimensions. If the chambers or sections are divided into equal dimensions, for example, battery modules with a uniformly specified dimension can be used, whereas if the chambers or sections are dimensioned differently, battery modules with different dimensions can be used. Alternatively, if the chambers or sections are dimensioned differently, battery modules of a uniform design can be installed in one chamber or section, and other battery components, such as electrical or electronic switching or control components, can be installed in another chamber or section using similar assembly measures via adapters. All of these variants, taken individually, can further increase modularity. If the partition wall or partition walls are not formed as one piece with the housing, this can also be used to adapt to the existing dimensions of the battery modules to be used.

Short description of the characters

• 1 zeigt in einer perspektivischen Seitenansicht ein Batteriegehäuse mit Adaptern gemäß der Erfindung;
• 2 zeigt eine Schnittdarstellung des Batteriegehäuses gemäß 1 mit aufgenommenen und befestigten Batteriemodulen;
• 3 zeigt eine perspektivische Detailansicht eines befestigten Adapters gemäß einer Ausführungsform;
• 4 zeigt in einer isometrischen Ansicht ein befestigter Adapter gemäß einer alternativen Ausführung; und
• 5 zeigt eine Schnittdarstellung des Adapters gemäß 4.

Preferred further embodiments of the invention are explained in more detail by the following description of the figures. In the figures:

• 1 shows a perspective side view of a battery housing with adapters according to the invention;
• 2 shows a sectional view of the battery housing according to 1 with battery modules picked up and secured;
• 3 shows a perspective detail view of a mounted adapter according to one embodiment;
• 4 shows in an isometric view a fixed adapter according to an alternative embodiment; and
• 5 shows a sectional view of the adapter according to 4 .

Detailed description of preferred embodiments

Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the various figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies.

In 1 A battery housing 10 is shown schematically in a perspective side view. The battery housing 10 comprises side walls 12 which define an inner cavity 16. In the present example, all side walls 12, together with a base plate (not shown), are formed integrally with one another in the form of a cast part. It can be seen that adapters 20, 22 are also fastened to the inner wall surfaces 14 of two opposite side walls 12, wherein the respective adapter 20 is designed as an adapter strip which extends longitudinally along the side wall 12. The adapter strip thus provides a continuous bearing structure for a battery module (not shown) to be accommodated in the inner cavity 16.

In this exemplary embodiment, the adapter strip 20 also has a total of five fastening means, which enable the fastening of the respective battery module to the adapter strip 20 and thus to the battery housing 10. To illustrate this, screws are screwed in, which protrude vertically from the adapter strip 20.

The fastening elements, here in the form of screws, are arranged in the vertical direction, which here also corresponds to the intended stacking direction of the battery modules.

An alternative embodiment is provided by the adapter 22, which is designed as a single adapter 22. These single adapters 22 are mounted on the corresponding inner wall surface 14 at a distance from one another in the longitudinal direction, whereby they together provide an interrupted storage structure for a battery module to be accommodated.

Both the adapter strip 20 and the individual adapters 22 are attached to predetermined receptacles on the corresponding inner wall surface 14. In this way, a predetermined height for the attachment of the battery modules can be determined, so that the stacked battery modules have a predetermined spacing from one another when assembled.

Furthermore, in the present example, an intermediate wall 18 is also provided, which divides the inner cavity 16 into two separate receiving spaces. Adapters 20, 22 are also provided for securing the battery modules, although only individual adapters 22 are shown in the present example. In this way, battery modules can be arranged not only stacked on top of one another, but also side by side. In the present embodiment, two battery modules can be arranged side by side.

The intermediate wall 18 is in this case fastened to the housing wall, but can optionally also be formed integrally or in one piece with the battery housing.

In 2 , the battery housing 10 is shown with battery modules 24 accommodated and fastened therein. The adapters 20, 22 are only partially shown. However, it can be seen that in the present example, three battery modules 24 or three battery module layers are stacked on top of one another, and each battery module layer has two battery modules 24 arranged next to one another, which are separated from one another by the intermediate wall 18. The sectional view shows that the battery modules 24 are fastened to the respective adapters 20, 22 by means of fastening screws screwed in vertically, i.e. in the stacking direction of the battery modules. The lowest battery module is fastened directly to the housing, while the battery modules arranged above it are fastened to the housing by means of the adapters 20, 22.

Furthermore, it can be seen that the opposite side walls 12 are slightly inclined outwards to the vertical, which runs essentially perpendicular to the base plate 13, in the stacking direction and thus lead away from each other upwards.

Detailed views of the screw connections for the adapter strip 20 and the single adapter are shown in 3 or in the 4 and 5 shown.

Accordingly, in 3 The adapter strip 20 is shown, with the adapter strip 20 being arranged above an already inserted battery module 24. In the present example, the adapter strip 20 represents a support structure for the topmost battery module yet to be inserted. This sectional view clearly shows that the screw 26 and its screw axis are inclined to the vertical. This results in a very space-saving fastening option.

In addition, the fastening means 28 are shown in more detail in this figure. The fastening means 28 are designed as sleeves or rivet nuts, each of which has an internal thread for receiving a corresponding fastening screw, as in 2 shown. The sleeves are firmly connected to the adapter bar 20.

An alternative version of the adapter is shown in the 4 and 5 shown, wherein the adapter is designed as a single adapter 22. In this way, even greater modularity can be provided, wherein the fastening option for the battery modules can be designed even more space-saving by means of the single adapters 22.

In the 4 and 5 the sleeve-shaped structure of the fastening means 28 is shown in more detail. Furthermore, in 5 clearly shows how the screw 26 is inclined at an angle of inclination 30 relative to the vertical. Because the inclination of the side walls 12 to the vertical is lower in the present example, the screw 26 is also inclined towards the side wall 12. In the present, non-limiting example, the angle of inclination lies in the range between 20 degrees and 40 degrees. This range has proven to be particularly advantageous both in terms of load distribution and in terms of the structural stability of the fastening relative to the side wall 12. However, it should be understood that the range of the angle of inclination 30 can be selected alternatively depending on the application and design of the battery modules or the adapter and the receptacles, in particular in the range between 10 degrees and 50 degrees.

Where applicable, all individual features shown in the embodiments may be combined and/or exchanged with one another without departing from the scope of the invention.

List of reference symbols

10

Battery case

12

side wall

13

base plate

14

Interior wall area

16

Inner cavity

18

partition wall

20

adapter

22

adapter

24

Battery module

26

screw

28

Fasteners

30

Angle of inclination

Claims (15)

Battery housing (10) for accommodating battery modules (24) comprising a plurality of battery cells, comprising at least two adapters (20, 22) for supporting at least one battery module (24), wherein the adapters (20, 22) are fastened by means of screws (26) in receptacles arranged on opposite inner wall surfaces (14) of the housing (10), wherein the respective screw axis of the screws (26) is inclined to the vertical, which corresponds to a stacking direction, characterized in that the battery housing (10) is designed for at least two battery module layers stacked one above the other and wherein each battery module layer comprises at least one battery module (24), wherein the at least one battery module (24) of the lowermost battery module layer is screwed directly to the battery housing (10) and each battery module (24) of a battery module layer arranged above the lowermost battery module layer is fastened to the housing (10) by means of adapters (20, 22). Battery housing (10) for accommodating battery modules (24) comprising a plurality of battery cells, comprising at least two adapters (20, 22) for supporting at least one battery module (24), wherein the adapters (20, 22) are fastened by means of screws (26) in receptacles arranged on opposite inner wall surfaces (14) of the housing (10), wherein the respective screw axis of the screws (26) is inclined to the vertical, which corresponds to a stacking direction, characterized in that the battery housing (10) is designed for at least two battery module layers stacked one above the other and at least two inner wall surfaces (14), which have at least some of the predetermined receptacles, are inclined to the vertical in such a way that a width of an inner cavity of the battery housing (10) widens in the stacking direction. Battery housing (10) according to Claim 1 or 2 , wherein the inclination of the respective screw axis is in the range between 10 degrees and 50 degrees, preferably between 20 degrees and 40 degrees. Battery housing (10) according to one of the preceding claims, wherein the battery housing (10) is designed for three or more battery module layers stacked one above the other and/or wherein each battery module layer comprises at least two battery modules (24) arranged next to one another. Battery housing (10) according to one of the preceding claims, wherein each adapter (20, 22) and/or each receptacle for each stacked battery module layer is of identical design and/or comprises an identical extension in the horizontal direction. Battery housing (10) according to one of the preceding claims, wherein at least one adapter (20, 22) is designed as an adapter strip (20) which extends along a respective inner wall surface substantially perpendicular to the stacking direction and has a plurality of fastening means (28) for fastening a respective battery module (24) or a plurality of battery modules (24) arranged next to one another. Battery housing (10) according to one of the preceding claims, wherein at least two adapters (22) each have a single fastening means (28) for fastening a battery module (24) and are spaced apart from one another along a respective inner wall surface (14) substantially perpendicular to the stacking direction. Battery housing (10) according to Claim 6 or 7 , wherein the fastening means (28) has a bearing surface which extends substantially perpendicular to the stacking direction, wherein the bearing surface has at least one bore with an internal thread for receiving a fastening screw of the respective battery module (24). Battery housing (10) according to one of the preceding claims, which comprises at least four side walls (12) defining an inner cavity (16) of the housing (10). Battery housing (10) according to one of the preceding claims, which is formed from a single part. Battery housing (10) according to Claim 9 which is made as a cast part or from a welded construction. Battery housing (10) according to one of the preceding claims, referring back to Claim 2 , wherein the inclination of the inner wall surfaces (14) in Range between 0.5 degrees and 5 degrees, preferably between 1 degree and 4 degrees. Battery housing (10) according to one of the preceding claims, referring back to Claim 2 , wherein the inclination of the inner wall surfaces (14) is designed as a demoulding slope. Battery housing (10) according to one of the preceding claims, comprising at least one intermediate wall (18) which is arranged between the inner wall surfaces (14), which have at least a part of the predetermined receptacles, and defines receiving spaces separate from one another for receiving battery modules (24) arranged next to one another, wherein at least one adapter (20, 22) is fastened to a respective predetermined receptacle on the intermediate wall surfaces by means of screws, wherein the respective screw axis of the screws (26) is inclined to the vertical. Battery housing (10) according to Claim 14 , wherein the at least one intermediate wall (18) in the housing (10) is mounted as a separate part in the housing (10) or is formed integrally with the housing (10).

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