Inter-cell cooling unit for battery module and battery module for motor vehicle

Abstract

The invention relates to an inter-cell cooling unit (10) for arrangement in a gap (20) between two battery cells (18) of a cell stack (14) arranged adjacent to each other in a stacking direction (S), the inter-cell cooling unit (10) having two cooling walls (24, 26), the cooling walls comprise a first cooling wall (24, 26) for arrangement on a first of the two battery cells (18) and a second cooling wall (26, 24) for arrangement on a second of the two battery cells (18), and wherein at least one free space (28) through which a coolant (40) can flow is formed between the first and second cooling walls (24, 26). In this case, at least one first opening (30, 32) is arranged in at least one of the two cooling walls (24, 26), via which a fluid connection is provided between at least the free space (28) and the environment of the inter-cell cooling unit (10).

Description

Technical Field

[0001] The present invention relates to an inter-cell cooling unit for a battery module, the inter-cell cooling unit is used to be arranged in the gap between two battery cells arranged adjacent to each other along the stacking direction of a battery cell stack / monocell group, wherein the inter-cell cooling unit has two cooling walls, the two cooling walls include a first cooling wall for being arranged on a first battery cell of the two battery cells and a second cooling wall for being arranged on a second battery cell of the two battery cells, wherein at least one free space through which a coolant can flow is formed between the first cooling wall and the second cooling wall. In addition, the present invention also relates to a battery module for a motor vehicle. Background Art

[0002] During operation, the battery cells of a battery module can be cooled by means of a cooling device. In this case, a cooling plate is often used, through which a coolant can flow and on which the battery module, for example a high-voltage battery for a motor vehicle, is arranged. In this way, only a small area of ​​the respective battery cell of the battery module can be cooled. The side of the battery cell with the largest area is usually the side facing the adjacent cell in the stacking direction or opposite to the stacking direction. Thus, more effective battery cell cooling can be provided by an inter-cell cooling unit, i.e. an element that can be arranged between two cells of such a cell stack.

[0003] Nevertheless, there is a desire to further increase the cooling efficiency for cooling such battery cells in battery modules, in particular for high-voltage batteries.

[0004] DE 10 2021 114 360 A1 describes an energy storage device having a battery cell stack consisting of a plurality of stacked and side-by-side energy storage cells and a cooling device having at least one heat-conducting element which is arranged between two adjacent energy storage cells and extends from a middle area between the two energy storage cells to a coolant line and is in thermal contact with the coolant line.

[0005] Furthermore, US 2001 / 0007728 A1 describes a battery pack having prismatic cells arranged parallel to one another and having cooling channels formed by structured intermediate plates made of a metallic material, which are located between the cells. Summary of the invention

[0006] The object of the present invention is to provide an inter-cell cooling unit and a battery module which enable cooling of the battery cells to be as efficient as possible.

[0007] This object is achieved by an inter-cell cooling unit and a battery module having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims, the description and the drawings.

[0008] Here, the inter-cell cooling unit according to the present invention for being arranged in the gap between two battery cells arranged adjacent to each other in the stacking direction of a battery cell stack has two cooling walls, which include a first cooling wall for being arranged on a first battery cell of the two battery cells and a second cooling wall for being arranged on a second battery cell of the two battery cells, wherein at least one free space through which a coolant can flow is formed between the first cooling wall and the second cooling wall. Here, at least one first opening / hole is arranged in at least one of the two cooling walls, through which a fluid connection is provided between the at least one free space and the environment of the inter-cell cooling unit.

[0009] This type of opening advantageously achieves that, when the inter-cell cooling unit is arranged as intended between two battery cells, the coolant flowing through at least one free space between the two cooling walls can directly contact the battery wall of the battery cell adjacent to the relevant cooling wall having the first opening through the opening. This advantageously further increases the cooling efficiency, since the battery cells adjacent to the inter-cell cooling unit can at least partially come into direct contact with the coolant flowing through the inter-cell cooling unit during operation. This advantageously allows the battery cells to directly contact the cooling medium or coolant flowing through the cooling plate between the cells, i.e., through the relevant inter-cell cooling unit.

[0010] At the same time, the inter-cell cooling unit can be used to counteract expansion pressures of the battery cells, which are caused, for example, by expansion of the battery cells during the service life of the battery cells and / or when the battery cells are charged. The inter-cell cooling unit can thus simultaneously serve as a spacer between the battery cells and for expansion compensation. Additional components can thereby be omitted.

[0011] In this case, the inter-cell cooling unit is preferably used in a battery module which has a cell stack with battery cells which are designed as prismatic battery cells or pouch cells.

[0012] Furthermore, the inter-cell cooling unit can have a base element which defines the part of the inter-cell cooling unit which is located within the gap between two battery cells arranged adjacent to each other in the stacking direction when the inter-cell cooling unit is arranged as specified between two battery cells. In addition to the base element, the inter-cell cooling unit can optionally also have at least one further component or at least one section which protrudes from the gap between two battery cells, in particular perpendicularly to the stacking direction. However, the inter-cell cooling unit can also be limited to the base element, that is, it can be arranged completely within the gap between two battery cells.

[0013] Here, the dimensions of the cooling wall, in particular the length and / or width of the cooling wall perpendicular to the stacking direction, can correspond to the length and width of the cell side of the battery cell adjacent to the relevant cooling wall. This is particularly advantageous because the contact area between the battery cell and the inter-cell cooling unit can be maximized. For example, the two cooling walls can be arranged substantially parallel to each other and are substantially flat. In addition, preferably, when the inter-cell cooling unit is arranged between two battery cells as required, the cooling walls are spaced apart from each other in the stacking direction, thereby providing at least one free space. In principle, the cooling wall, in particular the inter-cell cooling unit, can be made of any material as a whole. In particular, for the cooling wall, due to its high thermal conductivity, it is particularly suitable to use metal materials, such as aluminum. However, it is also conceivable to use non-metallic materials, such as plastics, to form the cooling wall. In addition, material combinations are also conceivable. In other words, individual elements of the inter-cell cooling unit, such as the first cooling wall and the second cooling wall, can be made of different materials, for example one cooling wall is made of aluminum and the other cooling wall is made of plastic.

[0014] At least one first opening is a recess in at least one of the two cooling walls. The opening is thus provided by a hole in the relevant cooling wall. For example, when the inter-cell cooling unit is arranged as specified between two battery cells, a part of the environment of the inter-cell cooling unit can be provided by at least one of the battery cells. When the inter-cell cooling unit is arranged as specified between two battery cells, the opening in at least one of the cooling walls can also be closed by a cell wall of one of the battery cells.

[0015] In this case, such a hole, or more precisely at least one first opening, can in principle have any geometric shape, such as a circle (especially a perfect circle or an ellipse), an elongated shape, an angular shape (such as a triangle, a quadrilateral, a pentagon), etc. It is also preferred that not only one such opening is provided in the relevant cooling wall, but a plurality of openings, in particular a large number of openings. This will be explained in more detail later. Thus, these openings can also be designed to differ from one another in terms of their size and / or geometry, or can be designed to be all identical.

[0016] In another advantageous embodiment of the invention, at least one first opening is arranged in the first cooling wall and at least one second opening is arranged in the second cooling wall, through which a corresponding fluid connection is provided between at least one free space and the environment of the inter-cell cooling unit. Therefore, when the inter-cell cooling unit is arranged in the cell stack as required, the other of the two battery cells, i.e. the battery cell adjacent to the second cooling wall, can also be cooled more effectively through the second opening, because now direct contact between the second battery cell adjacent to the second cooling wall and the cooling medium flowing through the inter-cell cooling unit can also be established through the second opening.

[0017] As will be explained in more detail later, there can be not only one free space between the two cooling walls, but also multiple free spaces, which are also referred to as sub-free spaces later. These sub-free spaces can be fluidically connected to each other, or they can also be fluidically separated from each other and form cooling channels that are separated from each other between the two cooling walls. The first opening in the first cooling wall can, for example, connect the interior of this first cooling channel to the ambient fluid of the inter-cell cooling unit, and the second opening can connect the interior of the second cooling channel of the inter-cell cooling unit to the ambient fluid of the inter-cell cooling unit. In other words, it is not necessary to establish a fluid connection between the environment of the inter-cell cooling unit and the same free space in the inter-cell cooling unit through the first opening and the second opening. But despite this, it is still feasible to do so.

[0018] Thus, for example, a first opening can establish a fluid connection between a first free space between two cooling walls and the environment of the inter-cell cooling unit, and a second opening can establish a fluid connection between a second free space between the two cooling walls and the environment of the inter-cell cooling unit, wherein, at least in the region of the inter-cell cooling unit located in the gap between two battery cells, the two free spaces can be fluidically separated from each other or fluidly connected to each other.

[0019] In another advantageous design of the present invention, the inter-cell cooling unit has a structural element, in particular an intermediate wall with a corrugated structure, which is arranged between the first cooling wall and the second cooling wall and divides the free space between the first cooling wall and the second cooling wall into a plurality of sub-free spaces. As described above, these sub-free spaces can be fluidically connected to each other or completely separated from each other. This depends on the structural element's construction scheme, which will be explained in more detail later. The great advantage of providing such a structural element is that the two cooling walls can be kept at a defined distance relative to each other. Therefore, the expansion force described above does not cause the inter-cell cooling unit to be completely flattened. Therefore, even if the expansion force of the battery cell acts on the cooling wall on both sides, the flowability of the inter-cell cooling unit can be ensured by the structural element. It is also particularly advantageous here that the structural element is provided as an intermediate wall with a corrugated structure. For example, such an intermediate wall can be configured as a corrugated plate. Such a corrugated structure has corresponding crests and troughs, wherein the crests of the corrugated structure of the intermediate wall can, for example, abut, or more precisely, contact the first cooling wall when the troughs contact the second cooling wall accordingly. A great advantage of this corrugated structure is that an elastic support can be provided between the two cooling walls. As a result, the described expansion forces can be absorbed particularly effectively. By arranging such an intermediate wall with a corrugated structure between the two cooling walls, the free space between the two cooling walls is automatically divided into sub-free spaces, which can provide corresponding cooling channels through the inter-cell cooling unit. This enables a flow through the inter-cell cooling unit in a defined manner. In principle, the intermediate wall can also be made of any material, for example, metal or plastic. Here, it is also conceivable that the components of the inter-cell cooling unit, in particular the two cooling walls and the intermediate wall, are made of different materials. For example, the intermediate wall can be made of plastic and the two cooling walls can be made of a metal material, or vice versa, the two cooling walls can be made of plastic and the intermediate wall can be made of metal.

[0020] Here, the intermediate wall and two adjacent cooling walls can be fixedly connected to each other, that is to say joined to each other. For example, in particular, depending on the material, the cooling wall and the intermediate wall can be welded to each other, bonded to each other or joined to each other by other joining methods.

[0021] According to a first variant, the intermediate wall can be designed to be fluid-tight. That is, the intermediate wall does not have any openings or other areas that can be penetrated by a fluid, especially a coolant (such as water, for example). Thus, the corresponding sub-free spaces are separated from each other in a fluid-tight manner.

[0022] According to another embodiment of the present invention, the intermediate wall has at least one third opening, through which at least two of the sub-free spaces are fluidically connected to each other. Advantageously, such a third opening can therefore allow the fluid flows flowing through the corresponding cooling channels to be mixed. For example, this allows for a better homogenization of the coolant temperature. It is also conceivable that the intermediate wall does not have just one such third opening, but rather has a hole pattern with a plurality of third openings. The hole pattern can be implemented as a regular hole pattern or an irregular hole pattern.

[0023] As explained in more detail below, this also applies to the cooling walls.

[0024] Correspondingly, another very advantageous design of the present invention is that a hole pattern including a first opening is arranged in at least the first cooling stave, and the hole pattern has a lot of first openings. Preferably, this also applies to the second cooling stave. In other words, preferably, a second hole pattern including a second opening is also arranged in the second cooling stave, and the second hole pattern has a lot of second openings. The description of the hole pattern in the first cooling stave can also be applied to the hole pattern in the second cooling stave in a corresponding manner.

[0025] For example, such a hole pattern with many first openings has the great advantage that, compared to one large opening, a particularly large contact area can be provided between the coolant flowing through the inter-cell cooling unit and the adjacent cell wall of the battery cell, and at the same time a high mechanical stability of the inter-cell cooling unit can be provided. In addition, this enables a more effective support of the intermediate wall between the two cooling plates. The intermediate wall then does not contact the cell side of the battery cell adjacent to the cooling wall. As a result, local pressure on the cell due to the corrugated pattern of the intermediate wall can be avoided. Despite the holes, the cooling wall then ensures a particularly uniform pressure distribution of the expansion forces on the battery cell.

[0026] In order to achieve an even more uniform or more adapted pressure distribution, it is also conceivable that the intermediate wall with the wave structure is configured so that the intermediate wall has different wave structures of different wavelengths in different regions. In other words, the distance between adjacent wave peaks of the wave structure can be greater in the first region of the intermediate wall than in the second region of the intermediate wall. For example, the wave structure can be configured so that it has a smaller wavelength in the central region based on the length and width perpendicular to the stacking direction than in the edge region, or vice versa.

[0027] In another very advantageous embodiment of the invention, the first openings of the first hole pattern are designed to be geometrically identical, in particular in terms of their shape and size, and in particular, the hole pattern is designed as a regular pattern. The hole pattern thus has self-repeating, in particular periodically repeating pattern units. This enables particularly uniform cooling of the adjacent cell sides and a simple construction and design of the hole pattern.

[0028] However, it is also conceivable that the individual holes of the hole pattern are designed differently or arranged differently from one another. Advantageously, this allows for targeted stronger or weaker cooling of adjacent battery cell regions and / or adaptation to different expansion forces of the cells in the central region and in the edge regions.

[0029] Therefore, another advantageous design of the present invention is that the hole pattern includes at least two first openings of different sizes from each other, one of these first openings is arranged in the edge area of ​​the first cooling wall, and the other first opening is arranged in the central area of ​​the cooling wall, and / or when the inter-cell cooling unit is arranged as specified between two battery cells, one of these first openings is arranged in the hot spot area of ​​the battery cell adjacent to the first cooling wall, and the other first opening is arranged in a cell area different from the hot spot area.

[0030] In this case, a hot spot region of a battery cell is a region of the battery cell in which the battery cell at least locally heats up most strongly at least during operation or, for example, during charging. Thus, during operation or during battery charging, such a hot spot region has the highest local cell temperature. A battery cell can also have a plurality of hot spots. These hot spots are often located near the cell poles.

[0031] Now, the design of the hole pattern with openings of different sizes advantageously enables, for example, larger openings to be provided in the region of such hot spots. This allows the adjacent cells to be cooled more strongly in these hot spots in a targeted manner. This allows a more uniform temperature distribution over the cells to be achieved.

[0032] Advantageously, openings of different sizes can also be used to provide different resistance forces to the expansion forces. For example, in the edge region of the battery cell, the adjacent openings can be smaller than in the central region, or vice versa.

[0033] Furthermore, the invention relates to a battery module for a motor vehicle, comprising a cell stack having at least two battery cells arranged next to each other in a stacking direction and an inter-cell cooling unit according to the invention or one of its embodiments arranged between the two battery cells.

[0034] The advantages described for the inter-cell cooling unit according to the invention and its embodiment therefore apply in the same manner to the battery module according to the invention.

[0035] For example, the battery cells can be designed as lithium-ion cells. Furthermore, the description of the battery module as already explained in conjunction with the inter-cell cooling unit can also apply to the battery module according to the invention and its design.

[0036] Conversely, the following description related to the inter-cell cooling unit should also provide other corresponding optional improvements to the inter-cell cooling unit described above.

[0037] A battery module can generally have not only two battery cells, but also a plurality of battery cells, which are provided in the form of a cell stack. A corresponding inter-cell cooling unit can be arranged between every two battery cells arranged adjacent to each other in the stacking direction. Each of these inter-cell cooling units can be configured as an inter-cell cooling unit according to the present invention or one of its embodiments. Here, the inter-cell cooling units can also be configured in different embodiments respectively.

[0038] In another advantageous embodiment of the present invention, a corresponding cooling channel extending from a corresponding channel inlet to a corresponding channel outlet is provided by the sub-free space, wherein the inter-cell cooling unit has: a first connecting element, such as a pipe, which is connected to the corresponding channel inlet and via which a coolant can be supplied to the inter-cell cooling unit; and a second connecting element, which is connected to the channel outlet and via which a coolant can be discharged from the inter-cell cooling unit. In addition, in this case, it is preferred that the region of the first cooling wall having at least one first opening, in particular a hole pattern, is arranged on the first battery cell where the first cooling wall is located so as to be sealed relative to the first battery cell by a seal surrounding this region of the first cooling wall. Thus, despite the hole pattern, it can still be ensured that the coolant does not leak. Here, the seal can be arranged in a circumferential manner in the edge region of the cell side of the first battery cell. Then, the seal is accordingly located, for example as a sealing contour, between the cell side of the first battery cell and the first cooling wall. Correspondingly, this also applies to the second battery cell and the second cooling wall.

[0039] In another advantageous embodiment of the present invention, the battery module has a cooling device including an inter-cell cooling unit, wherein the inlet and outlet of the corresponding cooling channels are connected to the ambient fluid of the battery module, and wherein the cooling device is configured so that when the cooling device is in operation, the battery cells are at least partially in contact with a coolant located outside the inter-cell cooling unit.

[0040] That is, in this case, the cooling device is provided as an open flow-through cooling device. In other words, in this case, the coolant can be in direct contact with the battery cells not only through the openings in the cooling wall but also in the area outside the inter-cell cooling unit. For this purpose, the cell stack can be arranged in a fluid-tightly implemented receptacle, so that the liquid coolant preferably does not leak. If, for example, the entire cell stack is located in the receptacle or is circulated by the coolant, a non-conductive coolant (such as oil) can be used as a coolant. Although less preferred, gas can also be used as a coolant. However, it is also possible that only a part of the battery cell is arranged in the receptacle, or a part of each battery cell included in the cell stack is arranged in the receptacle, wherein the part of the battery cell arranged in the receptacle is not the part where the cell pole is located. In other words, the cell housing can also be implemented to be electrically insulated to the outside, and the cell pole can be positioned outside the receptacle through which the coolant flows. So in this case, a conductive coolant can also be used, such as water or water with additives or other water-based coolants.

[0041] The invention also includes a refinement of the battery module according to the invention, which has the features already described in conjunction with the refinement of the inter-cell cooling unit according to the invention. For this reason, the corresponding refinement of the battery module according to the invention is not described again here.

[0042] The invention also relates to a high-voltage battery for a motor vehicle, which has at least one battery module according to the invention or one of its embodiments. The high-voltage battery can also have a plurality of such battery modules. The invention also includes a motor vehicle having a battery module according to the invention or one of its embodiments.

[0043] The motor vehicle according to the invention is preferably designed as a car, in particular a passenger car or a commercial vehicle, or as a bus or a motorcycle.

[0044] The present invention also includes combinations of features of the embodiments described. Therefore, the present invention also includes implementations which each have a combination of features of a plurality of the embodiments described, as long as these embodiments are not described as mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The following describes an embodiment of the present invention.

[0046] Figure 1 A schematic diagram showing at least a portion of an inter-cell cooling unit for a battery module according to one embodiment of the present invention is shown;

[0047] Figure 2 A schematic diagram of an inter-cell cooling unit according to another embodiment of the present invention is shown;

[0048] Figure 3 A schematic diagram of an inter-cell cooling unit according to another embodiment of the present invention is shown;

[0049] Figure 4 A schematic diagram showing a top view of an inter-cell cooling unit having a hole pattern according to another embodiment of the present invention;

[0050] Figure 5 A schematic diagram showing a top view of an inter-cell cooling unit having a hole pattern according to another embodiment of the present invention;

[0051] Figure 6 A schematic diagram showing a battery module with open circulation cooling according to one embodiment of the present invention is shown in a top view; and

[0052] Figure 7 A schematic diagram of an inter-cell cooling unit with a coolant coupling portion according to another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0053] The following embodiments are preferred embodiments of the present invention. In the embodiments, the described components of the embodiments are respectively individual features of the present invention that can be regarded as independent of each other, and these features also improve the present invention independently of each other. Therefore, the present disclosure should also include feature combinations that are different from the illustrated embodiment feature combinations. In addition, the embodiments may also be supplemented by other features in the already described features of the present invention.

[0054] In the figures, the same reference numerals respectively denote elements with the same function.

[0055] Figure 1 A schematic diagram of at least a portion of an inter-cell cooling unit 10 according to an embodiment of the present invention is shown. Here, the inter-cell cooling unit 10 or at least a portion thereof is shown in a three-dimensional diagram. Here, the inter-cell cooling unit 10 includes Figure 1 In the case of a defined arrangement in a cell stack 14 of a battery module 16 having a plurality of battery cells 18 arranged side by side in a stacking direction S, the base element 12 is arranged in a gap 20 between two battery cells 18 arranged adjacent to one another (see also Figure 6 Optionally, the inter-cell cooling unit 10 may also include regions, such as connection regions 22a, 22b, which may then be located outside the gap 20 between two battery cells 18, respectively (see Figure 7 ). The optional connection areas 22a, 22b are Figure 1 , but for the inter-cell cooling unit 10 described, and the inter-cell cooling unit 10 (in Figure 2 , Figure 3, Figure 4 and Figure 5 Here again only the base element 12 is shown, the connection region can also be provided optionally.

[0056] The base element 12 of the inter-cell cooling unit 10 now has two cooling walls 24, 26. The cooling walls 24, 26 have a distance d from each other in the y direction shown, which corresponds to the stacking direction S when the inter-cell cooling unit 10 is arranged as required in the cell stack 14. In addition, the cooling walls 24, 26 are essentially flat and parallel to each other. Preferably, the cooling walls 24, 26 are made of a metal material, but can also be made of plastic or any other material. Due to the distance d, at least one free space 28 through which a coolant can flow is provided between the two cooling walls 24, 26. When the inter-cell cooling unit 10 is arranged as required in the cell stack 14, the two cooling walls 24, 26 adjoin the cells 18 of such a cell stack 14 which are arranged correspondingly adjacent to each other. In particular, the cooling walls here adjoin the cell side faces indicated by 18a (see Figure 6 ).

[0057] Advantageously, the cooling walls 24, 26 are now each designed with an opening 30, 32. The openings 30 in the first cooling wall 24 can also be referred to as first openings 30, and the openings 32 in the second cooling wall 26 can also be referred to as second openings 32. For the sake of clarity, only some of the openings 30, 32 in each cooling wall 24, 26 are provided with reference numerals. Through these openings 30, 32, it is now advantageously possible for the coolant flowing through the base element 12, in particular through the free space 28, to come into direct contact with the cell side faces 18a of the cell 18. This can provide significantly more effective cooling and heat dissipation.

[0058] In addition, the base element 12 also includes an intermediate wall 34 with a corrugated structure. In this example, the intermediate wall 34 is configured as a corrugated plate 34. According to the corrugated structure, the corrugated plate 34 has a peak portion 34a and a trough portion 34b. Here, the peak portion 34a is also a contact area or a connection area with the first cooling wall 24, and the trough portion 34b provides a corresponding contact area or a connection area with the second cooling wall 26. Therefore, the intermediate wall 34 is connected to the first cooling wall 34 in the contact area provided by the peak portion 34a, and is connected to the second cooling wall 26 through the contact area provided by the trough portion 34b. The joint connection can be provided by a welding connection or an adhesive connection. Other construction schemes or joint schemes are also conceivable.

[0059] In addition, by the selected intermediate wall 34, the free space 28 between the cooling walls 24 and 26 is divided into individual sub-free spaces 28a and 28b. For the sake of clarity, only some of them are provided with reference numerals. The sub-free space represented by 28a is the sub-free space directly adjacent to the first cooling wall 24, and the sub-free space represented by 28b is the sub-free space directly adjacent to the second cooling wall 26. If necessary, the first sub-free space 28a can also be connected to the second sub-free space 28b in the following way, that is, the intermediate wall 34 is also configured with an opening or hole pattern, etc. The mixing of the fluid flow in the basic element 12 of the inter-cell cooling unit is thus achieved.

[0060] In the present example, the first opening 30 in the first cooling wall 24 and the second opening 32 in the second cooling wall 26 are arranged according to corresponding hole patterns 30', 32'. In the present example, the hole patterns 30', 32' are configured as regular hole patterns. In addition, in the present example, all openings 30, 32 are equally large and have the same geometry. But this need not necessarily be the case. In addition, in the present example, the first opening 30 is arranged in a region of the first cooling wall 24 that is not in direct contact with the intermediate wall 34 but is directly adjacent to the first sub-free space 28a. Correspondingly, the second opening 32 is also arranged in a region of the second cooling wall 26 that is directly adjacent to the second sub-free space 28b and is also not in direct contact with the intermediate wall 34. As a result, the coolant flowing through the cooling channel 36 provided by the corresponding sub-free spaces 28a, 28b can be particularly easy to contact with the cell wall 18a of the adjacent battery cell 18. In other words, the openings 30, 32 are not partially covered by the intermediate wall 34. However, it is also conceivable here that the above-described in more detail below and, for example, in Figure 7 Other design solutions are shown in .

[0061] The length L of the respective cooling wall 24, 26 or base element 12, defined in the example in the x-direction, and the width B of the cooling wall 24, 26 or base element 12, defined in the example in the z-direction, can correspond to the length and width of the respective cell wall 18a of the adjacent cell 18. As a result, particularly effective cooling of the cell 18 can be provided over the entire cell side 18a of the cell.

[0062] Figure 2 FIG. 1 shows a schematic diagram of an inter-cell cooling unit 10 or at least a part thereof, namely a basic element 12, according to another embodiment of the present invention. Here, the basic element 12 can be as shown in FIG. Figure 1The structure is described above, except that the hole patterns 30', 32' in the respective cooling walls 24, 26 are now slightly differently configured. In particular, the individual openings 30, 32 are designed slightly smaller here, especially in terms of their diameter, and twice the number of openings 30, 32 is provided for this purpose.

[0063] Figure 3 A schematic diagram of at least a portion of an inter-cell cooling unit 10, i.e. a base element 12 thereof, according to another embodiment of the present invention is shown. The base element can also be constructed as described above, except for the following difference, i.e., the first cooling wall and the second cooling wall 24, 26 now have a slightly different hole pattern 30'. Here, the corresponding openings 30, 32 providing the hole pattern 30', 32' are not designed as a perfect circle, but as an ellipse. In this example, the length of these openings in the x-direction is slightly greater than their respective widths in the z-direction.

[0064] Figure 4 A schematic diagram of a base element 12 of an inter-cell cooling unit 10 according to another embodiment of the present invention is shown in a top view looking at a first cooling wall 24. The following description in conjunction with the first cooling wall 24 can also be similarly applied to the second cooling wall 26, although the second cooling wall is not visible in this figure. The base element 12 can also be constructed as described above, except for the following difference, that is, each cooling wall 24, 26 is now configured again with a slightly different hole pattern 30'. The first cooling wall 24 is shown here by way of example. However, the hole pattern of the second cooling wall 26 can be configured to be the same or similar to the hole pattern 30' of the first cooling wall 24.

[0065] In the present example, the hole pattern 30' is formed by a plurality of openings 30 of different sizes and / or shapes. Here, 30a denotes the openings 30 in the central region of the base element 12 relative to the x-direction shown here, and 30b denotes the openings 30 in the corresponding edge region R relative to the x-direction. In the present example, the openings 30a in the central region Z are designed to be larger and more elongated than the openings 30b in the edge region. In particular, the hole size of the holes 30 decreases from the central region Z to the corresponding edge region R in the x-direction and in the direction opposite to the x-direction. However, the hole size and the geometry of the individual holes 30 in the z-direction remain unchanged.

[0066] Figure 5A schematic diagram of a base element 12 of an inter-cell cooling unit 10 according to another embodiment of the present invention is shown. Here again, another hole pattern 30 is shown, although in principle the base element 12 can be designed as described above. In this example, a central region Z' of the base element 12 is defined not only with respect to the x direction but also with respect to the z direction. Outside this central region Z, an edge region R' of the base element 12 can be defined. In this example, the opening 30 in the central region Z' (again represented by 30a) is designed to be smaller than the opening 30 in the edge region R', where the opening 30 in the edge region is also represented by 30b. Therefore, the hole size of the hole 30 can also increase from the central region Z' to the edge region R'. Here, the change in hole geometry and size can change in one direction, for example only in the x direction or only in the z direction, but can also change in two directions, namely in the x direction and in the z direction.

[0067] In principle, any other arrangement and design of the corresponding hole pattern 30' is also conceivable. For example, the hole size of the hole 30 can be adapted to the hot spot area of ​​the battery cell 18. Thus, larger holes 30 can be provided in the hot spot area of ​​the battery cell side 18a, so that the hot spot area is cooled more effectively than other areas of the battery cell side 18a with lower temperatures. By different hole sizes of the openings 30, a better adaptation to the expansion forces of the battery cell 18 can also be provided, which expansion forces are usually different in the edge area of ​​the battery cell 18 than in the central area of ​​the battery cell 18, in particular lower, which corresponds, for example, to the central area Z, Z' defined here of the base element 12.

[0068] By means of the number of holes, the hole pattern 30' or the hole shape, the degree of wetting of the cell surface 18a by the cooling medium can be adjusted in a targeted manner as desired or required. This provides a variety of advantageous adaptation options. The medium can flow directly through the cell wall 18a through the hole structure and dissipate heat.

[0069] Figure 6A schematic diagram of a battery module 16 according to an embodiment of the present invention is shown. The battery module 16 comprises a cell stack 14 having a plurality of prismatic battery cells 18 arranged side by side in a stacking direction S. Here, the cell sides facing each other are indicated by 18a. An inter-cell cooling unit 10 is arranged between each two cells 18 arranged adjacent to each other. In this example, the corresponding inter-cell cooling unit 10 consists only of a base element 12. In other words, in this example, the inter-cell cooling unit 10 does not have an area protruding from the gap 20 between two adjacent cells 18. The individual cooling channels 36 described above are implemented to be open at their ends with reference to the x direction shown here. In this example, the battery module 16 has a cooling device 38, which provides an open circulation of a cooling medium 40 to the cells 18. For this purpose, the battery module has a fluid-tight receptacle 42 in which the cell stack 14 is arranged. The receiving portion 42 can have an inlet connection 44 for supplying a cooling medium 40 and an outlet connection 46 for discharging the cooling medium 40 from the receiving portion 42, in particular after flowing through the gaps 20 between the cells 18 and in particular after flowing through the inter-cell cooling unit 10 arranged in the gaps 20. Here, the arrow 40' shows the cooling medium 40 flowing through the cooling channels 36 of the inter-cell cooling unit 10. The cooling medium 40 can then move freely within the receiving portion 42. Therefore, the cooling medium can also contact the sides of the battery 18 on which the inter-cell cooling unit 10 is not arranged. That is, in this case, the cell group 14 is directly in the fluid 40. Due to the pressure difference between the inlet and the return, that is, between the inlet connection 44 and the outlet connection 46, the fluid 40 flows between the cells 18 through the inter-cell cooling unit 10.

[0070] Alternatively, each inter-cell cooling unit 10 may also be provided with a connection for such an inflow portion and a return portion, such as in Figure 7 As shown schematically in FIG.

[0071] Here, Figure 7A schematic diagram of an inter-cell cooling unit 10 according to another embodiment of the present invention is shown. The inter-cell cooling unit can also be constructed as described above, except for the differences described below. The inter-cell cooling unit again includes a base element 12 and now, in addition to the base element 12, additionally includes connection areas 22a, 22b. Each of the connection areas 22a, 22b can be constructed with a pipe 50, 52. The coolant 40 can be supplied to the inter-cell cooling unit 10 and discharged from the inter-cell cooling unit 10 again via the pipe 50, 52. For example, the coolant can be input via the first pipe 50 and, after passing through the cooling channel 36 integrated in the base element 12, it can be discharged via the second pipe 52. In this case, in particular, in order to ensure that the coolant 40 does not leak despite the hole pattern 30', a seal 54 is also provided. The seal completely surrounds the area of ​​the base element 12 with the hole pattern 30'. Therefore, the seal 54 can be implemented to be directly adjacent to the edge 56 of the base element 12 in a closed and surrounding manner. When the inter-cell cooling unit 10 is arranged in the cell stack 14 as required, the seal 54 accordingly rests on the corresponding cell side surface 18a of the adjacent cell 18. The connection regions 22a, 22b then protrude from the gaps 20 between the cells 18, for example, in the x-direction and in the direction opposite to the x-direction. This makes it easier to connect the coolant supply line and the coolant discharge line to the corresponding pipes 50, 52. Here, for example, the coolant 40 can be supplied to the supply pipes 50 of a plurality of inter-cell cooling units 10 via a common supply line, and the coolant 40 flowing through the corresponding inter-cell cooling units 10 can also be discharged via a common discharge line, to which the corresponding discharge pipes 52 are connected.

[0072] In this example, the base element 12, in particular the cooling walls 24, 26, is also embodied with a slightly different hole pattern 30'. In this example, the openings 30 are not restricted to areas that are not in contact with the intermediate wall 34. With such a hole pattern with openings 30 that are in particular offset from one another, a particularly large through-area can be provided. According to the hole pattern 30' shown, a circular opening 30 is surrounded by six circular openings 30 of the same size. This is true for each of the openings 30, except for the openings in the edge region.

[0073] In summary, the examples show how the invention can provide an inter-cell cooling element in the form of a sandwich panel with perforated outer sheets. By combining a corrugated sheet structure with two perforated outer sheets as a spacer between prismatic cells, not only can the circulation of the coolant be ensured, but also the absorption of the expansion forces. Through the holes in the two outer sheets, a very good thermal connection of the cooling fluid to the cell can be ensured. Through the hole structure, the medium can flow directly over the cell wall and carry away the heat.

Claims

1. An inter-cell cooling unit (10), the inter-cell cooling unit being used to be arranged in a gap (20) between two battery cells (18) arranged adjacent to each other along a stacking direction (S) of a cell stack (14), -in, The inter-cell cooling unit (10) has two cooling walls (24, 26), the two cooling walls comprising a first cooling wall (24, 26) for being arranged on a first battery cell of two battery cells (18) and a second cooling wall (26, 24) for being arranged on a second battery cell of the two battery cells (18), and -in, At least one free space (28) through which a coolant (40) can flow is formed between the first cooling wall and the second cooling wall (24, 26). It is characterized in that At least one first opening (30, 32) is arranged in at least one of the two cooling walls (24, 26), through which a fluid connection is provided between at least one free space (28) and the environment of the inter-cell cooling unit (10).

2. The inter-cell cooling unit (10) according to claim 1, characterized in that: At least one first opening (30, 32) is arranged in the first cooling wall (24, 26) and at least one second opening (32, 30) is arranged in the second cooling wall (26, 24), through which respective fluid connections are provided between at least one free space (28) and the environment of the inter-cell cooling unit (10).

3. The inter-cell cooling unit (10) according to any one of the preceding claims, characterized in that: The inter-cell cooling unit (10) has a structural element (34), in particular an intermediate wall (34) with a corrugated structure, which is arranged between a first cooling wall and a second cooling wall (24, 26) and divides a free space (28) between the first cooling wall and the second cooling wall (24, 26) into a plurality of sub-free spaces (28a, 28b).

4. The inter-cell cooling unit (10) according to any one of the preceding claims, characterized in that: The intermediate wall (34) has at least one third opening, through which at least two of the partial free spaces (28a, 28b) are fluidically connected to one another.

5. The inter-cell cooling unit (10) according to any one of the preceding claims, characterized in that: A hole pattern (30', 32') comprising first openings (30, 32) is arranged at least in the first cooling wall (24, 26), the hole pattern having a plurality of first openings (30, 32).

6. The inter-cell cooling unit (10) according to any one of the preceding claims, characterized in that: The first openings (30, 32) are configured to be geometrically identical, in particular wherein the hole patterns (30', 32') are configured as a regular pattern.

7. The inter-cell cooling unit (10) according to any one of the preceding claims, characterized in that: The hole pattern (30', 32') comprises at least two first openings (30, 32) of different sizes, - one of the first openings is arranged in an edge region (R, R') of the first cooling wall (24, 26), and another of the first openings is arranged in a central region (Z, Z') of the first cooling wall (24, 26); - When the inter-cell cooling unit (10) is arranged as specified between two battery cells (18), one of the first openings is arranged in a hot spot area of ​​the battery cell (18) adjacent to the first cooling wall (24, 26), and the other first opening is arranged in a cell area different from the hot spot area.

8. A battery module (16) for a motor vehicle, comprising a cell stack (14) having at least two battery cells (18) arranged side by side in a stacking direction (S) and an inter-cell cooling unit (10) according to any of the preceding claims arranged between the two battery cells (18).

9. The battery module (16) according to claim 8, characterized in that: Respective cooling channels (36) extending from respective channel inlets to respective channel outlets are provided through sub-free spaces (28a, 28b), wherein the inter-cell cooling unit (10) comprises: a first connecting element (22a, 50; 22b, 52), which is connected to the respective channel inlets and via which a coolant (40) can be supplied to the inter-cell cooling unit (10); and a second connecting element (22a, 50; 22b, 52), which is connected to the channel outlet and via which a coolant (40) can be output from the inter-cell cooling unit (10), wherein a region of the first cooling wall (24, 26) having at least one first opening (30, 32), in particular a first hole pattern (30', 32') is arranged on a first battery cell (18) where the first cooling wall (24, 26) is located so as to be sealed relative to the first battery cell by a sealing member (54) surrounding the region of the first cooling wall (24, 26).

10. The battery module (16) according to claim 8, characterized in that: The battery module (16) has a cooling device (38), which includes an inter-cell cooling unit (10), wherein the inlet and outlet of the corresponding cooling channels (36) are connected to the ambient fluid of the battery module (16), wherein the cooling device (38) is designed so that when the cooling device (38) is in operation, the battery cells (18) are at least partially in contact with a coolant (40) located outside the inter-cell cooling element.

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