High-voltage battery, and vehicle comprising same

Abstract

The invention relates to a high-voltage battery (1) for a vehicle that is at least partially electrically powered, the high-voltage battery comprising a plurality of individual battery cells (2) which are positioned in a battery housing. The high-voltage battery according to the invention is characterised in that a crash absorber (6) is positioned between the individual battery cells (2) and at least one housing wall (5) of the battery housing. The high-voltage battery (1) can be installed in particular in the underfloor of a vehicle.

Description

[0001] Mercedes-Benz Group AG

[0002] High-voltage battery and vehicle with such a

[0003] The invention relates to a high-voltage battery for an at least partially electrically powered vehicle having a plurality of individual battery cells arranged in a battery housing. The invention also relates to a vehicle having such a high-voltage battery.

[0004] The term "high-voltage battery" is defined accordingly in the automotive sector by ECE 100R and is generally used. Such batteries are used as traction batteries in vehicles that are fully electrically powered and are referred to as battery-electric vehicles (BEVs). Such batteries can also be used in hybrid vehicles, whose drive energy is only partially provided by the high-voltage electric battery and which is partially generated, for example, by an internal combustion engine, a fuel cell, or similar.

[0005] By definition, a high-voltage battery has a relatively high energy content combined with a correspondingly high operating voltage. In vehicle use, damage to such a high-voltage battery, and in particular to one or more of the individual battery cells within such a high-voltage battery, can therefore pose a safety-critical issue. For example, intruded individual battery cells can react thermally, generating high levels of thermal energy that can potentially spread to neighboring cells and lead to thermal propagation of the entire high-voltage battery.

[0006] This must be avoided at all costs. A battery pack for this purpose is known from DE 10 2007 059 805 A1. The battery pack described therein comprises a battery housing and several individual battery cells. The individual battery cells are arranged in several cell modules, which in turn are held by fastening elements that penetrate the battery housing and form a load-bearing unit with it. In the event of a crash, forces are thus transmitted through the battery housing, whereby the very rigid battery housing with the fastening elements is ideally not deformed itself, in order to protect the individual battery cells. The batteries according to WO 2023 / 121 067 A1 and JP 2021-086679 A also follow a similar design principle.

[0007] For further information on the state of the art, reference can also be made to DE 102022 111 722 B3, which describes a carrier element that can accommodate a plurality of individual battery cells.

[0008] The disadvantage of a design with the most rigid battery housing possible is that it is comparatively complex to manufacture and accordingly heavy and expensive. This leads to an overall reduction in the potential energy density of such a high-voltage battery.

[0009] The object of the present invention is to provide an improved high-voltage battery according to the preamble of claim 1, which allows a simple and efficient construction in which the individual battery cells nevertheless enjoy good protection in the event of a crash.

[0010] According to the invention, this object is achieved by a high-voltage battery having the features of claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments of such a high-voltage battery according to the invention are set out in the dependent claims. Furthermore, a vehicle with such a high-voltage battery, as specified in claim 11, achieves the object.

[0011] The high-voltage battery according to the invention features a crash absorber arranged between the individual battery cells and at least one housing wall of the battery housing. In the event of damage to the battery housing in a crash, or if installed in the underbody of a vehicle, when driving over an obstacle, or when struck by a stone, the crash absorber protects the individual battery cells in the battery housing from intrusion.

[0012] The high-voltage battery according to the invention also provides that the crash absorber is geometrically designed in such a way that the individual battery cells are supported in their edge regions on the housing wall via support structures of the crash absorber, whereby central regions of the sides of the individual battery cells facing the housing wall remain free.

[0013] According to the invention, the individual battery cells are supported on the housing wall in their edge regions, i.e. where the material of the respective cell housing is arranged, via support structures which are part of the crash absorber. Any forces acting on the housing wall are thus diverted via the support structures into the individual cell housings, so that any impairment of the intermediate side surfaces of the respective individual battery cells can be largely avoided. The central regions of the sides of the individual battery cells facing the corresponding housing wall are free, so that the support structures are only arranged in the edge regions in such a way that they support the cell housings there, while in the central region there is no support from the crash absorber.

[0014] The individual battery cells can be constructed in any shape. However, the individual battery cells are particularly preferably designed as round cells arranged upright on the support structures. The crash absorber can therefore be arranged beneath the individual round cells, so that they are designed as cylindrical elements standing on the support structures of the crash absorber, with the edge regions and thus the cylindrical parts of the individual cell housings being supported accordingly on the support structures.

[0015] According to a very advantageous further development, this support can only be provided in partial sections of the edge regions, with these partial sections being evenly distributed over the circumference of the edge regions. The support can therefore, for example, be distributed around the circumference at three or more individual points, each for a part of the circumference. This allows for free channels to remain in between, so that, for example - and this is provided for in a particularly advantageous further development - the individual battery cells have their cell terminals and / or venting openings in the free central regions. These are thus particularly well protected, and at the same time, in the event that one of the venting openings is activated and pressurized gases escape from the cell housing, a flow path for these gases can be created between the support structures of the crash absorber.

[0016] Preferably, the support structures of several, or particularly preferably all, individual battery cells are connected to one another within the battery housing, with the connection being made via connecting webs, and with the connecting webs having a lower height than the support structures. The connecting webs can therefore, in principle, be arranged in any desired manner. In the event of a crash, the affected housing wall only touches the support structures due to the lower height of the connecting webs and, if necessary, transmits forces via them without the connecting structures being involved. These therefore only hold the support structures of the crash absorber in their intended positions.

[0017] According to a highly advantageous embodiment of the high-voltage battery according to the invention, the crash absorber can be made of a plastic material with incorporated fillers. Such a plastic material with incorporated fillers, such as reinforcing fibers and / or particles for specifically influencing the properties of the plastic, allows, on the one hand, simple and efficient production of the crash absorber and, on the other hand, enables a cost-effective and lightweight structure for the same, in which various properties such as mechanical stability, fire behavior, or the like can be easily influenced and thus tailored by the fillers.

[0018] This is particularly efficient when the individual battery cells are connected to one another via a potting compound. Such potting compounds for securing the individual battery cells are common, generally known and customary. The use of such a potting compound to create a stable composite from a large number of individual battery cells supports the functionality of the crash absorber. The crash absorber can transfer forces into the edge area of ​​each individual battery cell via its support structures. This area contains the cell casing on the one hand and the potting compound that connects the cell casing to neighboring cell casings on the other. These areas are very rigid, so that without additional elements, as is the case in the prior art, it is possible to dissipate the forces without having to fear intrusion of the individual battery cells.

[0019] According to a very advantageous embodiment, the crash absorber can be arranged at least on the underside of the individual battery cells between a base plate of the battery housing and the individual battery cells.

[0020] In a vehicle with such a high-voltage battery, the housing wall of the battery housing adjacent to the crash absorber can form an outer body surface. This means that impacts and the like acting on this wall are diverted via the crash absorber with minimal risk of intrusion of the individual battery cells. Particularly preferably, this outer body surface can be an underbody surface of the vehicle. The high-voltage battery is therefore positioned in the underbody area of ​​the vehicle, with the base plate of the battery housing simultaneously forming the lower end of the vehicle, i.e. its underbody plate. If obstacles are driven over, a stone is struck, or something similar occurs, this underbody can be exposed to corresponding forces and impacts. The crash absorber can ensure that this does not lead to the intrusion of individual battery cells.By using the battery housing wall as the vehicle's exterior surface, additional body elements on the vehicle's exterior can be eliminated. This saves material, installation space, and weight without compromising safety.

[0021] Further advantageous embodiments of the high-voltage battery and its crash absorber also emerge from the exemplary embodiment, which is described in more detail below with reference to the figures.

[0022] Showing:

[0023] Fig. 1 shows a section of a high-voltage battery according to the invention in a three-dimensional sectional view;

[0024] Fig. 2 is a view of the section shown in Fig. 1 from below without the base plate of the battery housing; Fig. 3 is a three-dimensional view of a possible embodiment of the crash absorber; and

[0025] Fig. 4 a top view and a side view of a section of a possible embodiment of a crash absorber for the high-voltage battery according to the invention.

[0026] Figure 1 shows a section of a high-voltage or HV battery 1. Such a high-voltage battery 1 typically consists of a plurality of individual battery cells 2. Figure 1 shows only the cell housings 21 of four such individual battery cells 2. To improve clarity, the active materials within the cell housings 21 of the individual battery cells 2 have been omitted.

[0027] The two individual battery cells 2 or cell housings 21 shown here in half section have their cell terminals pointing downwards in the illustration in Figure 1, which is indicated accordingly here by the two centrally arranged, for example, positive electrical poles 3 of the individual battery cells 2. They are additionally surrounded by a predetermined breaking point, each provided with the reference number 4, so that in the event of excess pressure within the respective individual battery cell 2 or its cell housing 21, the bottom surface of the cell housing 21 tears open along this predetermined breaking point 4, the middle part of the bottom folds downwards and hot gases can flow out of the cell housings 21 through the opening thus created.

[0028] The individual battery cells 2 are arranged in a battery housing, of which only one housing wall, designated 5, which here forms the base plate of the battery housing, is shown. The individual battery cells 2 are supported on this lower housing wall 5 via a crash absorber, designated as a whole by 6. The view in Figure 2, which shows the structure from below without the housing wall 5, once again shows how the individual battery cells 2 are arranged. They have the venting openings delimited by the predetermined breaking points 4 as well as cell terminals (not visible here) which contact the positive poles 3 and the cell housing 21 as the negative poles. A detailed illustration of the cell terminals has been omitted here for reasons of clarity. Furthermore, the crash absorber 6 can be seen in the illustration in Figure 2.As viewed in Figure 2, it is located in front of the cell housings 21 or individual battery cells 2 and essentially comprises the elements described below. These can also be seen in the illustration in Figure 1 and the subsequent illustration in Figure 3, which only shows the crash absorber 6 in a three-dimensional representation. These elements are, on the one hand, support structures designated by 61 and, on the other hand, connecting webs designated by 62, which connect the support structures 61 to one another and to the crash absorber 6.

[0029] The support structures 61, as the name suggests and as can be seen from the illustration in Figure 1, have the task of supporting the individual battery cells 2 on the housing wall 5. For this purpose, as can again best be seen from the illustrations in Figures 3 and 4, they have a first height which is greater than the height of the connecting webs 62 connecting them. These have a significantly lower height and are merely intended to hold the support structures 61 in position so that the vertically standing cylindrical cell housing walls 7, which can be seen in the illustration in Figure 1, can be supported directly on the housing wall 5 via the support structures 61. The connecting webs 62 preferably connect the support structures 61 to one another via annular sections.

[0030] In the central area of ​​the individual battery cells 2, no material of the crash absorber 6 is provided, so that these central areas remain free, as can be clearly seen in particular from the illustrations in Figures 2 and 3.

[0031] The support structures 61, which are evenly distributed over the circumference of each of the individual battery cells 2, support the individual battery cells 2 in case of doubt, for example if the housing wall 5 is impaired by mechanical deformation from below, as shown in Figure 1. They do not transmit forces into the area of ​​the bottom of the battery housing 21, but rather into its edge area and thus into the vertically running cell housing walls 7. Typically, a potting compound (not explicitly shown here) is also provided between the individual cell housing walls 7, so that the combination of potting compound and cell housing walls 7 can transmit the introduced forces very well without there being any risk of the bottoms of the individual battery cells 2 or their cell housings 21 being impaired. The mechanically comparatively unstable venting openings created by the predetermined breaking points 4 are thus reliably protected, as are the poles 3 and 4.Cell connectors in this area.

[0032] At the same time, the structure is designed to be simple and efficient to manufacture and comparatively lightweight. In particular, a plastic filled with glass fibers or glass beads, such as polyamide, can be used here. In the inventors' previous experiments, the material known as PA6 GF30 has proven to be very suitable.

[0033] This material can then be formed, for example, using an injection molding process, into the crash absorber 6 shown in Figure 4. Preferably, the crash absorber 6 can cover the entire (under)side of the HV battery 1 in a single crash absorber 6. The special design for the round cells is clearly visible in the top view of Figure 4a). The height difference between the support structures 61 on the one hand and the connecting webs 62 on the other hand is clearly visible in the side view of Figure 4b).This difference in height makes it possible, in the event that one or more venting openings of the individual battery cells 2 rupture and hot gases escape, for these gases to be diverted into their usual venting paths despite the crash absorber 6, because the crash absorber 6 remains permeable to these gases between the individual support structures 61, so that they can reach, for example, a central venting opening of the battery housing and from there be diverted into an area that is not critical from a safety perspective.

Claims

Mercedes-Benz Group AG Patent claims 1. High-voltage battery (1) for an at least partially electrically powered vehicle, with a plurality of individual battery cells (2) which are arranged in a battery housing, characterized in that a crash absorber (6) is arranged between the individual battery cells (2) and at least one housing wall (5) of the battery housing, wherein the crash absorber (6) is geometrically designed such that the individual battery cells (2) are supported in their edge regions on the housing wall (5) via support structures (61) of the crash absorber (6), wherein central regions of the sides of cell housings (21) of the individual battery cells (2) facing the housing wall (5) remain free.

2. High-voltage battery (1) according to claim 1, characterized in that the crash absorber (6) is formed from a plastic material with incorporated fillers.

3. High-voltage battery (1) according to claim 1 or 2, characterized in that the individual battery cells (2) are designed as round cells which are arranged upright on the support structures (61) of the crash absorber (6).

4. High-voltage battery (1) according to claim 1, 2 or 3, characterized in that the support is provided only in partial sections of the edge regions, said partial sections being arranged so as to be evenly distributed over the circumference of the edge regions.

5. High-voltage battery (1) according to one of claims 1 to 4, characterized in that the individual battery cells (2) have their cell terminals and / or their venting openings in the free central regions.

6. High-voltage battery (1) according to one of claims 1 to 5, characterized in that the support structures (61) of several or all of the individual battery cells (2) are connected to one another via connecting webs (62), wherein the connecting webs (62) have a lower height than the support structures (61).

7. High-voltage battery (1) according to one of claims 1 to 6, characterized in that the individual battery cells (2) are connected to one another via a potting compound.

8. High-voltage battery (1) according to one of claims 1 to 7, characterized in that the crash absorber (6) is arranged at least on the underside of the individual battery cells (2) between a housing wall (5) of the battery housing designed as a base plate and the individual battery cells (2).

9. High-voltage battery (1) according to one of claims 1 to 8, characterized in that the crash absorber (6) is made of a plastic reinforced with glass fibers or glass beads.

10. Vehicle with a high-voltage battery (1) according to one of claims 1 to 9, wherein the housing wall (5) of the battery housing adjacent to the crash absorber (6) forms an outer body surface, in particular an underbody surface.

Images