Battery housing and battery having a battery housing

Abstract

The invention relates to a battery housing (1), in particular for a battery of a vehicle, comprising a base (2), a cover (4) and a wall (3), wherein the wall (3) is arranged between the base (2) and the cover (3), wherein the base (2) comprises an inner region (7b), in which battery cells can be arranged, and an outer region (7a), in which the wall (3) is arranged, wherein at least one tension-resistant connecting element, preferably a plurality of tension-resistant connecting elements, (15), in particular in the form of one or more tie rods, is / are formed in the outer region (7b), wherein the base (2) and the cover (4) are connected by the at least one tension-resistant connecting element (15), wherein the wall (3) has at least one reinforcing element, in particular a plurality of reinforcing elements, (9), in particular in the form of ribs.

Description

[0001] Patent application

[0002] Battery housing and battery with battery housing

[0003] Description

[0004] The invention relates to a battery housing, in particular for a vehicle battery, comprising a base, a lid and a wall.

[0005] The invention also relates to a battery system comprising a battery housing and battery cells.

[0006] Although the present invention is generally applicable to any battery housing, the present invention is explained in relation to battery housings for vehicle batteries.

[0007] Battery housings for vehicle batteries are known in various forms, for example from DE 102018 202 478 A1. They comprise a base, a lid, and a wall, which together form a container in which the battery cells can be arranged. Particularly with plastic-based battery housings for vehicles, there is a possibility that in a vehicle collision, the mechanical stability of the battery housing, and thus the overall functionality of the battery, may be compromised. This can lead to battery cell fires.

[0008] To prevent this, it has become known to arrange longitudinal and transverse beams within the battery housing to increase the mechanical stability of the battery housing and reduce the risk of damage to the battery cells in the event of a vehicle collision. The longitudinal and transverse beams can extend parallel to a side surface of the wall within the battery housing.

[0009] One disadvantage is that the longitudinal and transverse beams reduce the available space within the battery housing, thus limiting the number of battery cells that can be used. Furthermore, the battery cell packs must be small relative to the available space in the battery housing in order to fit between the longitudinal and transverse beams.

[0010] One object of the present invention is therefore to provide a battery housing and a battery system in which the available installation space of the battery housing is better utilized. Furthermore, the battery housing and the battery system should exhibit high mechanical stability. Another object of the present invention is to provide an alternative battery housing and an alternative battery system.

[0011] In one embodiment, the present invention solves the aforementioned problems by means of a battery housing, in particular for a vehicle battery, comprising a base, a lid and a wall, wherein the wall is arranged between the base and the lid, wherein the base comprises an inner region in which battery cells can be arranged and an outer region in which the wall is arranged, wherein at least one, preferably several, tensile-resistant connecting elements, in particular in the form of one or more tie rods, are formed in the outer region, wherein the base and the lid are connected by the at least one tensile-resistant connecting element, and wherein the wall has at least one, in particular several, reinforcing elements, in particular in the form of ribs.

[0012] In one embodiment, the present invention solves the aforementioned problems by means of a battery system comprising a battery housing according to one of claims 1 to 13 and battery cells arranged in the battery housing.

[0013] One of the advantages achieved is that the battery housing exhibits sufficiently high mechanical stability, particularly against lateral and / or frontal intrusion due to dynamic, static, and / or quasi-static loads. This allows for a reduction in the number of longitudinal and / or transverse beams within the battery housing, thereby increasing the available installation space. A further advantage is the reduction in the likelihood of the battery housing being dented, which is particularly high in a vehicle collision. The reinforcing elements, preferably designed as ribs, serve to distribute and transfer the load to the tie rods.

[0014] The term "base" is to be understood in the broadest sense and refers, particularly in the claims, preferably in the description, to a single housing base or on its own, a single underride guard or on its own, and / or a combination of at least one housing base and at least one underride guard. In particular, the base of the battery housing can be an integral part of an underride guard of a vehicle.

[0015] The term "tensile-resistant connecting element" is to be understood in the broadest sense and refers, particularly in the claims and preferably in the description, to a rod-shaped object with a tensile stiffness of at least 10 kN, preferably at least 20 kN, and particularly at least 30 kN. For example, the tensile-resistant connecting element may be a tension anchor, preferably a shear anchor, made of a metal, particularly steel, which may extend along the wall of the battery housing. The tensile-resistant connecting element may comprise one or more fixing elements at one or two end regions, with which the tensile-resistant connecting element can be fixed to the bottom and / or lid of the battery housing.

[0016] The term "wall" is to be understood in the broadest sense and refers, particularly in the claims and preferably in the description, to a boundary of an interior space of the battery housing arranged between the base and the lid. The wall can be a separate component and / or integrally connected to the base and / or the lid of the battery housing. In particular, the base, the lid, and / or the wall can consist of, be made of, and / or comprise a plastic, especially a rigid plastic. Advantageously, the plastic used comprises a thermoplastic, such as polyamide 6 (PA6), polyamide 6.6 (PA6.6), polyamide 6.10, polyamide 6.12 (PA6.12), polycarbonate (PC), and polypropylene (PP), and / or a thermoset, such as unsaturated polyester (UP), epoxy (EP), polyurethane (PU), phenolic resin (PF), and / or vinyl ester (VE).

[0017] The term "reinforcing element" is to be understood in the broadest sense and refers, particularly in the claims and preferably in the description, to one or more areas of the wall which, by virtue of their geometry and / or material properties, provide a local increase in mechanical stability, especially against indentation of the battery housing. In particular, the reinforcing elements may be local increases in the wall thickness, especially in the form of ribs. The ribs may extend wholly or partially along the wall from the bottom to the top. In particular, the reinforcing elements may be used for load distribution and the introduction of forces into the tensile-resistant connecting elements.

[0018] Further features, advantages and further embodiments of the invention are described below or become apparent therein.

[0019] According to an advantageous embodiment of the invention, the inner area is free of crossbeams between the base and the lid and / or between a first wall of the casing and a wall of the casing opposite the first wall and / or between a second wall of the casing and a wall of the casing opposite the second wall, wherein the second wall is arranged adjacent to the first wall. In other words, the inner area of ​​the casing can be free of longitudinal beams and / or free of crossbeams and / or free of vertical beams. An advantage of this is that more battery cells can be arranged in the battery casing.

[0020] According to a further advantageous embodiment of the invention, the at least one tensile-resistant connecting element is arranged within the at least one reinforcing element. In particular, several, preferably all, connecting elements can each be arranged within a single reinforcing element. Thus, the connecting elements can be arranged in a region of the wall that has an increased thickness due to the reinforcing elements. An advantage of this is that the connecting elements can be securely arranged within the wall. A further advantage is that the probability of a connecting element, for example, breaking out of the wall can be reduced.

[0021] According to a further advantageous embodiment of the invention, a cooling element is arranged in the lid and / or the base. This cooling element allows battery cells within the battery housing to be cooled. The cooling element can, for example, be made of a metal, particularly a metal with high thermal conductivity. An advantage of this is that cooling of the battery cells can be achieved in a simple and cost-effective manner and with minimal installation space. Another advantage is that the cooling element can increase the rigidity of the base and / or the lid.

[0022] According to a further advantageous embodiment of the invention, the lid has a stiffness between 50% and 200%, preferably between 75% and 150%, and particularly between 85% and 115%, of the stiffness of the base. In particular, the lid and the base can have approximately the same stiffness. For example, contact surfaces of the battery cells, intermediate floors, and / or underbody protection of the vehicle can be used to adjust the stiffness of the lid and / or the base. An advantage of this is that a uniform mechanical load distribution within the battery housing can be achieved.

[0023] According to a further advantageous embodiment of the invention, the reinforcing elements have a stiffness of less than 50%, preferably less than 15%, and particularly less than 5%, of the stiffness of the at least one tensile-stiff connecting element. An advantage of this is that, due to the difference in stiffness, when a force is applied to the battery housing, the force can be absorbed on the one hand by plastic deformation of the reinforcing elements, and on the other hand, the connecting elements can prevent the battery housing from being indented.

[0024] According to a further advantageous embodiment of the invention, at least two reinforcing elements are arranged and connected by a circumferential flange. In particular, the reinforcing elements can form part of the circumferential flange. The circumferential flange can, for example, be integrally connected with the reinforcing elements and / or the wall, for example, by injection molding, and thus be manufactured in one piece with the wall. An advantage of this is that a force acting on the wall can be distributed across many reinforcing elements.

[0025] According to a further advantageous embodiment of the invention, the circumferential flange has a fiber reinforcement, in particular a continuous fiber reinforcement. In particular, the fiber reinforcement can extend along the wall of the housing. For example, the continuous fiber reinforcement can comprise a thermoplastic composite material. An advantage of this is that the mechanical stability of the battery housing against indentation is further increased. In particular, the fiber reinforcement can prevent the formation of cracks within the battery housing.

[0026] According to a further advantageous embodiment of the invention, the reinforcing elements are positioned at an angle of 40° to 80°, particularly between 70° and 50°, and preferably between 55° and 65°, from the wall, and in particular, the reinforcing elements intersect. In other words, the reinforcing elements do not extend perpendicularly from the wall, but are arranged at an angle to it. The reinforcing elements can each project from the wall in two different directions at this angle, so that they intersect. An advantage of this is that the mechanical strength of the wall is increased. Another advantage is that the required volume of plastic can be reduced, since the intersecting reinforcing elements create cavities that are not filled with plastic.Furthermore, it is conceivable that each axis extending along a maximum extent of the reinforcing elements has an angle of less than 15°, preferably less than 10°, and particularly less than 5°, to an axis extending along a maximum extent of the tension-resistant connecting elements. In particular, the ribs or reinforcing elements are aligned almost flush with a longitudinal axis of the tie rods or connecting elements. An advantage of this is that the probability of shearing under lateral loads can be reduced.

[0027] According to a further advantageous embodiment of the invention, the distance along a vertical line through the base and the lid between the circumferential flange and the base is more than 115%, preferably more than 140%, and particularly more than 165%, of the distance between the circumferential flange and the lid, and / or the distance between the circumferential flange and the lid is more than 115%, preferably more than 140%, and particularly more than 165%, of the distance between the circumferential flange and the base. In other words, the flange is arranged off-center with respect to the distance between the base and the lid and / or is designed asymmetrically with respect to the base and the lid. An advantage of this is that rotationally induced moments of the flange in one direction can be better compensated.

[0028] According to a further advantageous embodiment of the invention, the reinforcing elements each have a first region arranged above the circumferential flange and a second region arranged below the circumferential flange, wherein the first region has a different modulus of elasticity and / or a different cross-section and / or a different draft angle than the second region. In other words, the reinforcing elements exhibit a gradient of stiffness in the direction from bottom to top. An advantage of this is that forces acting on the reinforcing elements in a specific direction can be better compensated.

[0029] According to a further advantageous embodiment of the invention, the at least one tensile-resistant connecting element exhibits a stiffness gradient in the tensile direction, in particular by means of a change in the cross-section of the tensile-resistant connecting element in the tensile direction. The tensile direction is, in particular, a direction parallel to a maximum extent of the connecting element and / or parallel to a perpendicular through the base and the cover. An advantage of this is that forces acting on the connecting elements in a specific direction can be better compensated.

[0030] According to an advantageous embodiment of the invention, at least one tensile-resistant connecting element is made of two different materials. The tensile-resistant connecting element can, for example, be made of aluminum and steel. This allows for a gradient in the Young's modulus of the tensile-resistant connecting element.

[0031] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the accompanying description of the figures based on the drawings.

[0032] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0033] Preferred embodiments and configurations of the present invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components or elements.

[0034] Figure 1 shows a section of a battery housing according to an embodiment of the present invention;

[0035] Figure 2 shows a battery housing according to an embodiment of the present invention in a cutaway view;

[0036] Figure 3 shows a section of a battery housing according to an embodiment of the present invention;

[0037] Figure 4 shows a section of the wall of the battery housing according to Figure 1;

[0038] Figure 5 shows a section of a battery housing without plastic according to an embodiment of the present invention.

[0039] Figure 1 shows a section of a battery housing according to an embodiment of the present invention.

[0040] The battery housing 1 comprises a base 2, a wall 3, and a lid 4, wherein the base 2 and the wall 3 are integrally connected. The lid 4 is plate-shaped and designed to close an interior space 5 of the battery housing 1. It is also conceivable that the lid 4 and the wall 3 are integrally connected, or that the base 2, the lid 4, and the wall 3 are each manufactured separately. A cooling element 6, for example in the form of loop- or meander-shaped cooling channels embedded in the lid 4, is arranged on or in the lid 4, and that battery cells (not shown), which can be inserted into the interior space 5 of the battery housing 1, can be cooled by means of the cooling element 6.

[0041] The wall 3 surrounds the battery housing 1 and connects the base 2 to the lid 4. Specifically, the wall 3 comprises four walls 3a-3d (only three walls 3a, 3b, 3d are shown in Figure 1) that surround the interior 5 on four sides. These four walls 3a-3d are arranged in an outer region 7a of the base 2, whereas the battery cells (not shown) can be arranged in an inner region 7b of the base 2.

[0042] In the inner area 7b, two longitudinal beams 8a, 8b are arranged, connecting the walls 3a, 3c (not shown), as well as the base 2 and the lid 4, but no transverse beams connecting the walls 3b, 3d. It is also conceivable that neither longitudinal nor transverse beams are arranged in the inner area 7b. Furthermore, it is conceivable that only vertical beams connecting the base 2 and the lid 4 are arranged in the inner area 7b. Finally, it is conceivable that no vertical beams are arranged in the inner area 7b.

[0043] The wall 3 comprises reinforcing elements 9 arranged in the form of ribs on an outer surface 10 of the wall 3. In particular, the entire outer surface 10 is provided with such ribs 9. The ribs 9 are designed here as local increases in the thickness of the wall 3, extending outwards. The ribs can extend from the base 2 to the cover 4. In addition, the ribs include projections 11 that extend away from the wall 3 and are arranged intersecting each other, forming a lattice structure. The lattice structure is connected by a circumferential flange 12 that extends along the wall 3 and, in particular, once around the entire battery housing 1. Connecting elements in the form of tie rods (not shown in Figure 1) are arranged within the ribs 9. These tie rods and the circumferential flange 12 are shown in more detail in Figure 2.

[0044] Beneath the base 2, a reinforcement layer 13 is provided, which may be connected to the base 2. The reinforcement layer 13 can, for example, be an intermediate layer or an underbody protection layer and serves to increase the stiffness of the base 2, in particular its modulus of elasticity. Through the reinforcement layer 13, the base 2 and the cover 4, through the cooling element 6, exhibit approximately the same modulus of elasticity. Both the underbody protection layer and the cover 4 can provide a "shear field absorption" capability, meaning that both the cover 4 and the base 2 can absorb forces in the event of lateral contact between the battery housing 1 and a foreign object.

[0045] Figure 2 shows a battery housing according to an embodiment of the present invention in a sectional view.

[0046] The battery housing 1 can be designed, in particular, as shown in Figure 1. A connecting element 15 in the form of a tie rod is arranged in the wall 3, specifically in a rib 9, of the battery housing 1. The tie rod comprises a shaft 16, at or in the ends of which a screw 17a, 17b is arranged. The screws 17a, 17b are each screwed into a thread in the shaft 16. The base 2 and the cover 4 are connected to each other by means of the tie rods 15. The tensile force of the tie rod 15 can be adjusted by actuating the screws 17a, 17b. Figure 2 shows only one tie rod 15, but several tie rods 15 can be arranged in the housing 1; in particular, a tie rod 15 can be arranged in each rib 9. It is also conceivable that tie rods 15 are arranged only in individual walls 3a-3d.Alternative fastening methods for the tie rods 15 to the cover 4 and / or base 2 are also conceivable, for example riveting, welding and / or positive locking.

[0047] The circumferential flange 12 incorporates a fiber reinforcement 18, in this case in the form of a continuous circumferential fiber reinforcement. The combination of the ribs 9, the tie rods 15, and / or the continuous fiber reinforcement 18 increases the mechanical stability of the battery housing 1 to such an extent that longitudinal, transverse, and / or vertical beams within the battery housing 1 can be omitted.

[0048] In Figure 2, the flange 12 is arranged centrally between the base 2 and the cover 4. It is also conceivable that the flange 12 is arranged off-center, as shown in Figure 3.

[0049] Figure 3 shows in schematic form a section of a battery housing according to an embodiment of the present invention.

[0050] Figure 3 shows a battery housing 1 in which the flange 12 is arranged off-center. This means that the distance 19a between the flange 12 and the base 2 differs from the distance 19b between the flange 12 and the cover 4.

[0051] Furthermore, Figure 3 on the right shows an alternative tie rod 15 which has a thickness gradient along its tension direction 20. The battery housing 1 can have one or more such tie rods 15 with thickness gradients.

[0052] Figure 4 shows a section of the wall of the battery housing according to Figure 1.

[0053] Figure 4 shows an enlarged section of the wall 3 of the battery housing 1 according to Figure 1. Each rib 9 comprises two extensions 11a, 11b, each extending away from the wall 3. These extensions 11a, 11b do not extend perpendicularly from the wall 3, but at an angle 21a, 21b of approximately 60°. The extensions 11a, 11b extend in opposite directions, so that they intersect. At their end regions 22, the extensions 11a, 11b are connected by the circumferential flange 12. It is also conceivable that the circumferential flange 12 extends from the wall 3 to the end regions 22 of the extensions 11a, 11b.

[0054] The ribs 9 have a distance 23 of approximately 5 mm to 50 mm, preferably of 10 mm to 40 mm, in particular of 20 mm to 35 mm, from each other.

[0055] Figure 5 shows a section of a battery housing without plastic according to an embodiment of the present invention.

[0056] Figure 5 shows a section of a battery housing, in particular the battery housing according to Figure 1, in which those parts of the battery housing that are made of and / or manufactured from plastic are not shown. A plurality of tie rods 15 are arranged along the wall, surrounded by the continuous fiber reinforcement 18. Additionally, tie rods 7b can be arranged in the inner area by means of which the lid and the bottom of the battery housing (not shown in Figure 5) can be connected.

[0057] In summary, at least one embodiment of the present invention may have at least one of the following features and / or provide at least one of the following advantages:

[0058] - Large installation space inside the battery housing.

[0059] - High mechanical stability. Although the present invention has been described using preferred embodiments, it is not limited to these and can be modified in many ways.

[0060] Reference symbol list

[0061] 1 battery case

[0062] 2 floors

[0063] 3 walls

[0064] 3a-3d Walls of the wall

[0065] 4 lids

[0066] 5 Interior

[0067] 6 cooling elements

[0068] 7a Outer area

[0069] 7b Inner area

[0070] 8a, 8b longitudinal beams

[0071] 9 reinforcing elements

[0072] 10 Outer surface of the wall, 11a, 11b Processes

[0073] 12 Circumferential flange

[0074] 13th amplification level

[0075] 15 Connecting element

[0076] 16 shaft

[0077] 17a, 17b screw

[0078] 18 Fiber reinforcement

[0079] 19a, 19b distance

[0080] 20 Direction of travel

[0081] 21a, 21b Angle

[0082] 22 end areas

[0083] 23 distance

Claims

Claims 1. Battery housing (1), in particular for a vehicle battery, comprising a base (2), a cover (4) and a wall (3), wherein the wall (3) is arranged between the base (2) and the cover (4), wherein the base (2) comprises an inner region (7b) in which battery cells can be arranged and an outer region (7a) in which the wall (3) is arranged, wherein at least one, preferably several, tensile-resistant connecting elements (15), in particular in the form of one or more tie rods, are formed in the outer region (7b), wherein the base (2) and the cover (4) are connected by the at least one tensile-resistant connecting element (15), wherein the wall (3) has at least one, in particular several, reinforcing elements (9), in particular in the form of ribs.

2. Battery housing (1) according to claim 1, characterized in that the inner area (7b) is free of cross members (8a, 8b) between the base (2) and the lid (4) and / or between a first wall (3a) of the wall (3) and a wall (3c) of the wall (3) opposite the first wall (3a) and / or between a second wall (3b) of the wall (3) and a wall (3d) of the wall (3) opposite the second wall (3b), wherein the second wall (3b) is arranged adjacent to the first wall (3a).

3. Battery housing (1) according to claim 1 or 2, characterized in that the at least one tensile-resistant connecting element (15) is arranged in the at least one reinforcing element (9).

4. Battery housing (1) according to one of claims 1 to 3, characterized in that a cooling element (6) is arranged in the lid (4) and / or in the base (2).

5. Battery housing (1) according to one of claims 1 to 4, characterized in that the lid (4) has a stiffness between 50% and 200%, preferably between 75% and 150%, in particular between 85% and 115%, of the stiffness of the base (2).

6. Battery housing (1) according to one of claims 1 to 5, characterized in that the reinforcing elements (9) have a stiffness of less than 50%, preferably less than 15%, in particular less than 5%, of the stiffness of the at least one tensile-stiff connecting element (15).

7. Battery housing (1) according to one of claims 1 to 6, characterized in that at least two reinforcing elements (9) are arranged which are connected by a circumferential flange (12).

8. Battery housing (1) according to one of claims 1 to 7, characterized in that the circumferential flange (12) has a fiber reinforcement (18), in particular a continuous fiber reinforcement.

9. Battery housing (1) according to one of claims 1 to 8, characterized in that the reinforcing elements (9) project from the wall (3) at an angle (21a, 21b) between the reinforcing elements (9) and the wall (3) of 40° to 80°, in particular between 70° and 50°, preferably between 55° and 65°, in particular wherein the reinforcing elements (9) intersect.

10. Battery housing (1) according to one of claims 1 to 9, characterized in that a distance (19a, 19b) along a vertical through the base (2) and the lid (4) between the circumferential flange (12) and the base (2) is more than 115%, preferably more than 140%, in particular more than 165%, of the distance between the circumferential flange (12) and the lid (4) and / or that the distance between the circumferential flange (12) and the lid (4) is more than 115%, preferably more than 140%, in particular more than 165%, of the distance between the circumferential flange (12) and the base (2).

11. Battery housing (1) according to one of claims 1 to 10, characterized in that the reinforcing elements (9) each have a first area which is arranged above the circumferential flange (12) and each have a second area which is arranged below the circumferential flange (12), wherein the first area has a different modulus of elasticity and / or a different cross-section and / or a different draft angle than the second area.

12. Battery housing (1) according to one of claims 1 to 11 , characterized in that the at least one tensile-stiff connecting element (15) has a stiffness gradient in the tensile direction (20), in particular by a change in the cross-sectional area of ​​the tensile-stiff connecting element (15) in the tensile direction.

13. Battery housing (1) according to one of claims 1 to 12, characterized in that the at least one tensile-resistant connecting element (15) is made of two different materials is manufactured.

14. Battery system comprising a battery housing (1) according to any one of claims 1 to 13 and battery cells arranged in the battery housing (1).

Images