High-voltage battery for a motor vehicle and motor vehicle

Abstract

The invention relates to a high-voltage battery (12) for a motor vehicle (10), comprising a battery housing (14) enclosing a total receiving space (16) having a height (H) in a first direction (z), a width (B) in a second direction (y) and a length (L) in a third direction (x), wherein the height (H) is smaller than the length (L) and the width (B), and comprising a first cell stack (22, 23) received in the total receiving space (16) with several battery cells (24) arranged side by side in a stacking direction (z). The stacking direction (z) is parallel to the first direction (z) and the high-voltage battery (12) includes a maximum of three cell stacks (22, 23) including the first cell stack (22, 23), wherein, if the high-voltage battery (12) includes more than the first cell stack (22, 23), the maximum of three cell stacks (22, 23) are arranged side by side in the third direction (x).

Description

[0001] The invention relates to a high-voltage battery for a motor vehicle, comprising a battery housing that encloses a total receiving space having a height in a first direction, a width in a second direction, and a length in a third direction, wherein the height is less than the length and the width. The high-voltage battery also includes a first cell stack contained within the total receiving space, with several battery cells arranged side by side in a stacking direction. Furthermore, the invention relates to a motor vehicle with such a high-voltage battery.

[0002] High-voltage batteries, especially those used in motor vehicles, typically comprise numerous battery cells. These cells can generally be designed as prismatic, pouch, or cylindrical cells. Pouch or prismatic cells are typically used to form a cell stack, arranged in a stacking direction with their largest surfaces facing each other. Cooling the battery cells of such a high-voltage battery is often necessary. Cooling plates, for example, can be used for this purpose. Such cooling is particularly efficient when the largest possible surface area of ​​a battery cell can be connected to the cooling plate. Since the largest surfaces of the battery cells in a cell stack face each other, for most effective cooling, a cooling plate should be positioned between each pair of cells.However, this requires enormous installation space, which in turn reduces the vehicle's range, and is also very complex to implement. Furthermore, other components and systems of such a high-voltage battery become very complex due to the large number of battery cells, for example, the electrical interconnection of the battery cells, and so on. If one wanted to reduce the number of battery cells without reducing the overall energy content of such a high-voltage battery, it would be necessary to make the battery cells larger. However, the size of the battery cells is limited by certain factors. A high-voltage battery is often installed in the underbody of a vehicle. This means that there is only limited installation space available, especially in the vertical direction of the vehicle, so the battery cells cannot be made any taller.The thickness of the battery cells in the stacking direction, which typically corresponds to the vehicle's longitudinal or transverse direction, cannot be arbitrarily large, as otherwise effective and efficient cooling of the cell would no longer be possible. In other words, if the battery cells are too thick, they cannot be adequately cooled internally. Therefore, to ensure optimal temperature control, the cells should not be too thick in at least one direction. This leaves only the option of maximizing the dimensions of such a battery cell in the remaining third spatial direction. However, even then, an extremely large number of battery cells are still required to provide a high-voltage battery.

[0003] US 2020 / 0411916 A1 describes a battery pack with several battery cells arranged side by side in a stacking direction, between which cooling plates made of metal may be arranged.

[0004] US patent 2022 / 0384879 A1 describes a battery module with flat battery cells and cooling plates that are stacked alternately.

[0005] The object of the present invention is to provide a high-voltage battery and a motor vehicle that allow a simplified design of a high-voltage battery, in particular one that allows a design with the fewest possible individual cells.

[0006] This problem is solved by a high-voltage battery and a motor vehicle with the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0007] A high-voltage battery according to the invention for a motor vehicle comprises a battery housing enclosing a total receiving space having a height in a first direction, a width in a second direction, and a length in a third direction, wherein the height is less than the length and the width. Furthermore, the high-voltage battery comprises a first cell stack contained within the total receiving space, with several battery cells arranged side by side in a stacking direction. The stacking direction is parallel to the first direction, and the high-voltage battery, including the first cell stack, comprises a maximum of three cell stacks. If the high-voltage battery comprises more than the first cell stack, the maximum of three cell stacks are arranged side by side in the third direction.

[0008] The battery cells are positioned within the overall receiving space such that their stacking direction points towards the height of the receiving space, which represents the smallest dimension of the overall receiving space. In other words, the battery cells can be positioned, so to speak, flat within the receiving space, with the cell thicknesses oriented towards the height of the overall receiving space. The cell thicknesses preferably represent the smallest dimensions of the battery cells, thus allowing for efficient cooling. Since the cells are now positioned within the overall receiving space with their thicknesses aligned in the direction where the overall receiving space is already severely limited in its dimensions, it is also possible to design the length and width of the cells to be very large in the two remaining spatial dimensions, namely the second and third spatial dimensions.With regard to the preferred installation position in a motor vehicle, positioning the cells horizontally rather than vertically allows for significantly larger individual battery cells in both the transverse and longitudinal directions of the vehicle. Furthermore, in the vertical direction, where available installation space is already severely limited, the cells can be designed with relatively thin profiles, which in turn benefits battery cell cooling. This enables the high-voltage battery to be supplied with a very small number of individual cells. For example, the high-voltage battery could consist of only the first cell stack, which could then essentially fill the entire available space within the battery housing. It is also conceivable, for instance, to arrange two or at most three such cell stacks side by side in a third direction.In this case, the high-voltage battery can still be constructed with significantly fewer individual cells than would be possible if the individual cells were stacked vertically as usual, with the stacking direction of such a cell stack oriented, for example, longitudinally or transversely to the vehicle. The battery cells can now be designed as very flat and large plates. This simplifies, for example, the cooling of the battery cells, since even if a cooling plate is placed between each pair of battery cells, the number of cooling plates required is extremely small.The wiring and interconnection effort for the battery cells is also significantly reduced, firstly because the total number of cells in the high-voltage battery is extremely low, and secondly because such interconnection can now be advantageously implemented laterally, and the number of cell stacks to be interconnected is also extremely small. This significantly simplifies the overall construction of such a high-voltage battery.

[0009] The high-voltage battery is designed to provide a voltage in the high-voltage range, meaning greater than 60 volts. The high-voltage battery can also be designed to provide a voltage of at least 400 volts or at least 800 volts. This voltage is provided by the maximum of three cell stacks as the battery voltage. The total storage space can be the only storage space for the high-voltage battery, in particular the battery housing. The total storage space can optionally be subdivided into several compartments, especially if the high-voltage battery comprises multiple cell stacks. If the high-voltage battery comprises only the first cell stack as a single cell stack, the total storage space can be provided as a single, contiguous space. The battery housing can also be considered the complete battery housing.In other words, all battery cells contained within the high-voltage battery should be arranged within this battery housing. The battery housing can, for example, comprise a base, a frame surrounding the entire receiving space, and a lid. The entire receiving space can therefore be completely enclosed by the battery housing.

[0010] With regard to the intended installation position of the high-voltage battery in a motor vehicle, it is preferred that the first direction is parallel to a vertical direction of the vehicle, the second direction parallel to a transverse direction of the vehicle, and the third direction parallel to a longitudinal direction of the vehicle. Since the length of the total battery compartment is greatest, or can be greatest, in the third direction with such an installation position, it is advantageous, at least if the high-voltage battery comprises several cell stacks, for example, two or a maximum of three cell stacks, for these to be arranged side by side in the third direction. In the second direction, therefore, multiple cell stacks of the high-voltage battery are not arranged side by side. In other words, the first cell stack can extend substantially over the entire battery compartment in the second direction. Similarly, multiple cell stacks can be arranged one above the other in the first direction.Therefore, with respect to the first direction, there is no further cell stack next to the first cell stack.

[0011] The battery cells can be designed, for example, as lithium-ion cells. In particular, the battery cells can be designed as lithium iron phosphate cells. Furthermore, the battery cells can be designed, for example, as pouch cells or prismatic battery cells. Preferably, the battery cells are designed as prismatic battery cells, in particular as particularly flat prismatic battery cells whose thickness in the first direction is the smallest dimension and is, in particular, significantly smaller than their cell length and cell width in the third and second directions, respectively.

[0012] The battery cells of an identical cell stack are arranged, particularly in the stacking direction, with their largest surface areas facing each other. A cooling plate can also be located between the battery cells, as explained in more detail later, and / or they can also be arranged in direct contact with each other.

[0013] Accordingly, a further highly advantageous embodiment of the invention is achieved when the battery cells are each designed as prismatic flat cells, having a cell height in the first direction of less than 1 cm and a cell width in the second and a cell length in the third direction of several decimeters each, in particular a cell width and / or cell length of at least one meter. The cell height of each battery cell is therefore preferably less than 1 cm, in particular a maximum of 5 mm. This allows for particularly effective cooling of the battery cell when a cooling plate is arranged on the side with the largest surface area. In particular, with such a thin design of the battery cells, it is not necessary, for example, to provide cooling on both sides of each battery cell. Thus, additional cooling plates can be saved.Furthermore, it is preferred that at least one dimension of such a battery cell is at least one meter. This can be the cell width or, alternatively, the cell length, or both the cell width and the cell length can be at least one meter. If the high-voltage battery comprises several cell stacks, the cell length in the third direction, in which these cell stacks are then arranged side by side, may be less than one meter. However, even then, it is advantageous if the cell length is, for example, at least 50 cm or more.

[0014] Preferably, this applies to all battery cells comprised of the high-voltage battery, even if the battery comprises multiple cell stacks. If the high-voltage battery comprises multiple cell stacks, these can be essentially identical. In other words, the features and properties described with reference to the first cell stack can also apply to the optional subsequent cell stacks of the high-voltage battery.

[0015] According to a further advantageous embodiment of the invention, the high-voltage battery, including the first cell stack, comprises a maximum of two cell stacks arranged side by side in the third direction, each extending substantially over the entire total receiving space in the first and second directions. "Substantially" here can be understood, for example, as at least 90%, preferably at least 95%. If the high-voltage battery comprises a maximum of two cell stacks, which can be easily achieved by making the battery cells of the respective cell stacks longer in the third direction, the total number of battery cells can be further reduced, and the effort required to construct the high-voltage battery can also be further reduced.

[0016] It is therefore particularly advantageous, as provided for in a further embodiment of the invention, that the high-voltage battery comprises only the first cell stack, which extends substantially over the entire total receiving space in the third direction. In this case, each battery cell of the first cell stack has a cell length of at least one meter in the third direction, and particularly also in the second direction. A cell length in this case can even be on the order of approximately two meters, and generally, for example, between 1.6 meters and 2.2 meters.

[0017] The height of the recording space in the first direction and, correspondingly, essentially the height of the first cell stack as well as the optional further cell stacks are preferably less than 20 cm, in particular less than 15 cm and greater than 5 cm, for example approximately 10 cm.

[0018] According to a further advantageous embodiment of the invention, the high-voltage battery comprises at least one cooling plate arranged between at least two battery cells of the first cell stack. If the high-voltage battery comprises several cell stacks, the cooling plate can also be arranged simultaneously between two battery cells of the optionally further cell stack, or the high-voltage battery can comprise at least one further cooling plate arranged between two cells of the further cell stack.

[0019] A cooling plate of this type allows for advantageous cooling of the battery cells over a large area. The battery cells are thus positioned with their largest surface areas facing the cooling plate and, in particular, are arranged in direct contact with it. Especially with very thin battery cells, this enables particularly efficient cooling of the battery cells using cooling plates positioned between them. Depending on the number and thickness of the battery cells, the high-voltage battery can also include several cooling plates per cell stack. It is advantageous if each cell in a cell stack, especially the first cell stack, is arranged in direct contact with at least one such cooling plate.It may be provided that each cell of a cell stack, in particular of the first cell stack, is arranged in direct contact with only one such cooling plate or is arranged in direct contact with two such cooling plates.

[0020] Furthermore, it is highly advantageous if the cooling plate includes at least one cooling channel through which a coolant, particularly a liquid coolant, can flow. If the high-voltage battery is operated as intended in a motor vehicle, the cooling plate, especially if the high-voltage battery is to be cooled, will therefore be permeated by such a coolant. Liquid cooling provides a significantly stronger cooling effect than, for example, gas cooling or similar methods.

[0021] Furthermore, it is highly advantageous to arrange a cooling plate between each pair of battery cells in the first cell stack, and optionally also analogously for the optionally subsequent cell stacks. This allows each battery cell, at least except for the cells at the edges of the cell stack, to be cooled on both sides by such a cooling plate. The cells at the edges can also be cooled on both sides by such a cooling plate. This plate can then be positioned between such a cell at the edge and a housing wall of the battery casing, which can be provided, for example, by the casing wall itself, such as the bottom and / or the lid.

[0022] Furthermore, the invention also relates to a motor vehicle with a high-voltage battery according to the invention or one of its embodiments.

[0023] Furthermore, it is highly advantageous if the first direction is parallel to a vehicle's vertical axis. The first cell stack therefore comprises horizontally stacked battery cells. This makes it possible to design the cells to be particularly large in two spatial directions, namely the second and third directions, while maintaining a relatively small thickness in the first direction, thus enabling particularly effective cooling.

[0024] Furthermore, it is an advantageous embodiment of the invention if the third direction is parallel to a longitudinal axis of the vehicle. Particularly when the high-voltage battery comprises several cell stacks, for example two or a maximum of three, it is advantageous if these are arranged side by side in the direction of the vehicle's longitudinal axis, since the dimensions of the high-voltage battery can be larger in the longitudinal direction of the vehicle than in the transverse direction.

[0025] The high-voltage battery can, for example, be located in the underbody of the vehicle. It can therefore be positioned below the passenger compartment. For instance, the high-voltage battery, in particular the battery housing and / or the overall housing space, or even the battery cells of the first cell stack, can extend from the front axle of the vehicle to the rear axle. In the transverse direction of the vehicle, the high-voltage battery, or its housing and / or the overall housing space, or even the first cell stack, can extend from one of the two side sills to the opposite side sill.

[0026] The invention also includes further developments of the motor vehicle according to the invention, which have features already described in connection with the further developments of the high-voltage battery according to the invention. For this reason, the corresponding further developments of the motor vehicle according to the invention are not described again here.

[0027] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0028] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0029] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of a motor vehicle with a high-voltage battery in a top view according to an embodiment of the invention; Fig. 2 a schematic representation of a high-voltage battery for a motor vehicle in a top view according to a further embodiment of the invention; and Fig. 3 A schematic cross-sectional representation of a high-voltage battery for a motor vehicle according to an embodiment of the invention.

[0030] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0031] In the figures, identical reference symbols denote functionally equivalent elements.

[0032] Fig. Figure 1 shows a schematic representation of a motor vehicle 10 with a high-voltage battery 12 according to an embodiment of the invention. The high-voltage battery 12 comprises a battery housing 14, which encloses a receiving space 16 for the high-voltage battery 12. The housing 14 includes a frame 18 that surrounds the receiving space 16 in the circumferential direction. The battery 12, or rather the motor vehicle 10, is shown here in a top view along the z-direction, which is aligned parallel to the vertical direction of the motor vehicle 10. The y-direction corresponds to a transverse direction of the vehicle, and the x-direction corresponds to a longitudinal direction of the vehicle. The housing 14 can also include a housing base 20 (see Figure 1). Fig. 3) include a housing cover (not shown). In the receiving space 16, a cell stack 22 with several battery cells 24 stacked in a stacking direction z is arranged, which are designed as prismatic flat cells 24. In the present example, the high-voltage battery 12 comprises only a single such cell stack 22, which is arranged in the receiving space 16. Fig. Figure 3 shows, for example, a schematic cross-sectional view of the high-voltage battery 12 in a side view, in which the housing 14 with the frame 18 and the housing base 20 and the cell stack 22 with the battery cells 24 stacked on top of each other in the z-direction can be seen.

[0033] As in Fig. As shown in Figure 1, the receiving space 16 has a width B in the y-direction and a length L in the x-direction. Each battery cell 24 of the cell stack 22 has a cell length ZL in the x-direction and a cell width ZB in the y-direction. Furthermore, the receiving space 16 and the cell stack 22 have a height H in the z-direction, as shown, for example, in Fig. Figure 3 is shown. The individual cells 24 each have a cell thickness ZD, as also shown in Figure 3. Fig. 3 is illustrated.

[0034] Furthermore, cooling plates 26 of a cooling device for cooling the battery cells 24 can be arranged between the cells 24 of the cell stack 22. The cooling plates 26 can include cooling channels through which a coolant flows.

[0035] In the present example, the cell stack 22 essentially fills the entire receiving space 16. The cell stack 22, and consequently each individual cell 24, can have a width ZB of approximately one meter, for example, and a length ZL of more than one meter, for example, approximately two meters. The cell thicknesses ZD, on the other hand, are relatively small and preferably less than 1 cm, e.g., a maximum of 0.5 cm. By positioning the cell stack 22 such that the stacking direction z is parallel to the vehicle's vertical direction z, it is advantageously possible to design the individual cells 24 to be particularly large in the transverse direction y and the longitudinal direction x of the vehicle. This allows the high-voltage battery 12 to be provided with a very small number of cells 24.This design also simplifies the cooling of the individual cells 24, which can be easily achieved by placing cooling plates 26 between the cell plates 24. The wiring for coolant supply and discharge, as well as the interconnection of the cells 24, is also greatly simplified.

[0036] Fig. Figure 2 shows a schematic representation of a high-voltage battery 12 for a motor vehicle 10 according to a further embodiment of the invention. The high-voltage battery 12 can be configured as described above, except that in the present example it comprises not just one cell stack 22, but two cell stacks 22, 23. The cell stacks 22 can, however, be configured as described above. Fig. 1 and Fig. The cell stacks 22 and 23 are designed as described in section 3, except that the individual cell lengths ZL are smaller in the present example, e.g., essentially half the size. The two cell stacks 22 and 23 are thus arranged side by side in the longitudinal direction x of the vehicle. The two cell stacks 22 and 23 together essentially fill the entire receiving space 16. This space can optionally be divided into two compartments by a partition between the cell stacks 22 and 23, although this is not strictly necessary. In this case as well, the cells 24 of the cell stacks 22 and 23 are stacked in a stacking direction z that corresponds to the vehicle's vertical direction z. The cell thicknesses ZD are again preferably less than 1 cm and, for example, have a maximum thickness of 0.5 cm. The cells 24 can therefore also be designed as very large but thin prismatic cells 24. A cooling plate 26 can again be located between the cells 24, as described in section 3. Fig.3 described. In general, it is not necessary for a cooling plate 26 to be located between each pair of cells 24; for example, only one cooling plate 26 can be arranged between each adjacent pair of two cells 24. In particular, only one cooling plate 26 can be adjacent to each cell 24.

[0037] Overall, the examples demonstrate how the invention can provide a cell-to-pack prismatic approach. Currently, battery cells are typically installed vertically in vehicles or battery housings. This severely limits the dimensions of such cells. Vertical installation of cells quickly reaches its size limits. The height of the battery housing and the thickness of the cells are particularly problematic with this vertical installation, as the housing cannot be built taller and the cells should not be significantly thicker to allow for cooling. Furthermore, this does not allow for an optimal cooling surface area for large cells.The high-voltage battery according to the invention and its embodiments now advantageously make it possible to provide very flat cell modules or very flat battery cells with a very large cross-sectional area, wherein the cells are intended to rest with their largest cross-sectional area or side surface facing downwards, i.e., towards the bottom of the housing. A cooling plate of the same size can then follow. This design enables very large cells, both in terms of cell area and volume, optimal cell cooling, and optimal space utilization. The battery cells, which have a very large cross-section on one side, i.e., a very large side surface, can then be assembled together with module plates to form a large module. Ideally, the side surface of a single cell and of the module can be as large as the space in the battery housing.If a single module of such a size proves technically unfeasible, multiple modules with the same logic can be installed. Preferably, however, the high-voltage battery comprises a maximum of three cell stacks, and preferably a maximum of two cell stacks. 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] US 2020 / 0411916 A1

[0003] US 2022 / 0384879 A1

[0004]

Claims

[1] High-voltage battery (12) for a motor vehicle (10), comprising: - a battery housing (14) enclosing a total receiving space (16) having a height (H) in a first direction (z), a width (B) in a second direction (y) and a length (L) in a third direction (x), wherein the height (H) is less than the length (L) and the width (B), and - a first cell stack (22, 23) recorded in the overall recording space (16) with several battery cells (24) arranged next to each other in a stacking direction (z), characterized by , that the stacking direction (z) is parallel to the first direction (z) and the high-voltage battery (12) including the first cell stack (22, 23) comprises a maximum of three cell stacks (22, 23), wherein, if the high-voltage battery (12) comprises more than the first cell stack (22, 23), the maximum of three cell stacks (22, 23) are arranged side by side in the third direction (x). [2] High-voltage battery (12) according to claim 1, characterized by , that the battery cells (24) are each designed as prismatic flat cells (24) having a cell height (ZD) in the first direction (z) of less than 1 cm and a cell width (ZB) in the second direction (y) and a cell length (ZL) in the third direction (x) of several decimeters each, in particular a cell width (ZB) and / or cell length (ZL) of at least one meter. [3] High-voltage battery (12) according to any one of the preceding claims, characterized by , that the high-voltage battery (12) including the first cell stack (22, 23) comprises a maximum of two cell stacks (22, 23) arranged side by side in the third direction (z), and which extend substantially over the entire total receiving space (16) in the first and second directions (z). [4] High-voltage battery (12) according to any one of the preceding claims, characterized by, that the high-voltage battery (12) comprises only the first cell stack (22), which extends in the third direction (x) essentially over the entire total receiving space (16). [5] High-voltage battery (12) according to any one of the preceding claims, characterized by , that a cooling plate (26) is arranged between at least two battery cells (24) of the first cell stack (22, 23). [6] High-voltage battery (12) according to any one of the preceding claims, characterized by , that the cooling plate (26) comprises at least one cooling channel through which a coolant, in particular a cooling liquid, can flow. [7] High-voltage battery (12) according to any one of the preceding claims, characterized by , that a cooling plate (26) is arranged between each pair of battery cells (24) of the first cell stack (22, 23). [8] Motor vehicle (10) with a high-voltage battery (12) according to one of the preceding claims. [9] Motor vehicle (10) according to claim 8, characterized by, that the first direction (z) is parallel to a vehicle vertical axis. [10] Motor vehicle (10) according to claim 8 or 9, characterized by , that the third direction (z) is parallel to a longitudinal axis of the vehicle.

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