Cell separating element for arrangement between two cells and battery module for motor vehicle

Abstract

The invention relates to a cell separating element (10) for arrangement in a gap (42) between two cells (36) of a cell stack (16) arranged adjacent to each other in a stacking direction (y), having a flexible first outer wall (12) and a flexible second outer wall (14), which are at least partially connected to each other in an edge-side circumferential manner, between the first outer wall (12) and the second outer wall (14) there is an interior (30) of the cell separating element (10). The cell separating element (10) comprises an intermediate plate (18) arranged between a first outer wall (12) and a second outer wall (14), on which at least one elastic first support element (20a) is arranged, which elastically supports the intermediate plate (18) against the first outer wall (12), and on which at least one elastic second support element (20b) is arranged, which elastically supports the intermediate plate (18) against the second outer wall (14). The second support element elastically supports the intermediate plate (18) against the second outer wall (14).

Description

Technical Field

[0001] The present invention relates to a cell separator element for being arranged in a gap between two cells arranged adjacent to each other in a stacking direction of a cell group, wherein the cell separator element is designed to be elastically compressible at least partially in a first direction, which first direction corresponds to the stacking direction when the cell separator element is arranged in the gap, wherein the cell separator element has a first flexible outer wall with a first inner side and a second flexible outer wall with a second inner side, wherein the first outer wall and the second outer wall are opposite in the first direction so that the first inner side faces the second inner side, wherein the first outer wall and the second outer wall are at least partially connected to each other around the edge side, wherein an inner cavity of the cell separator element is present between the first outer wall and the second outer wall. In addition, the present invention also relates to a battery module for a motor vehicle. Background Art

[0002] For example, battery modules with lithium-ion cells generate heat during the charging and discharging phases. If the temperature reaches a critical value, spontaneous combustion may occur, which is also called propagation. In addition, during the charging and discharging phases, the lithium-ion cells expand, which is called swelling. In this case, the cells may swell and shrink periodically. In order to prevent the spread of propagation from one cell to the next, separators are often used, which are mostly made of ceramic material and are arranged between the cells. However, these plates are mostly very hard and cannot absorb the expansion forces, which can lead to excessive mechanical stresses in the cells. In addition, the separators are very strongly insulated, so that heat can hardly be dissipated via the separators.

[0003] It is therefore desirable to have the possibility of firstly dissipating heat from the cells as well as possible and secondly providing the best possible thermal barrier between the cells in the event of propagation and additionally absorbing the expansion forces as well as possible during normal operation.

[0004] DE 10 2021 121 397 A1 describes an arrangement according to which thermally insulating compression mats, for example made of polyurethane, silicone foam or a neoprene-based foam material, are arranged between the battery cells.

[0005] DE 10 2021 132 874 A1 describes a cell separator element having two contact surfaces and a shape memory material which increases the distance between the contact surfaces when a limiting temperature is exceeded.

[0006] DE 20 2013 001 662 U1 describes a composite heat sink for arrangement between battery cells, which composite heat sink includes a central gas generating layer, two flexible graphite layers, and a protective sleeve enclosing these layers. When an extreme temperature is exceeded, the gas generating layer generates gas, whereby the composite heat sink expands, and thus the composite heat sink serves as a thermal fuse.

[0007] EP 4 181 277 A1 describes a metal cooling fin for arrangement between battery cells, which metal cooling fin is designed to have a smaller thickness in a central region in order to better adapt to the bulging geometry of the battery cells.

[0008] Generally speaking, when providing battery cell separating elements, it is difficult to reconcile the aspects of good heat dissipation during normal operation, good expansion characteristics, and good heat insulation in the case of thermal runaway of the battery cells. Summary of the Invention

[0009] Therefore, the object of the present invention is to provide a battery cell separating element and a battery module, which can achieve: providing the best possible heat dissipation during normal operation, providing the best possible heat insulation characteristics in the case of thermal runaway of the battery cells, and at the same time providing the best possible expansion compensation.

[0010] This object is achieved by a battery cell separating element and a battery module having the features described in the respective independent claims. Advantageous designs of the present invention are the subject matter of the dependent claims, the description, and the drawings.

[0011] The battery cell separating element according to the present invention for arrangement in the gap between two battery cells arranged adjacent to each other in the stacking direction in a battery cell group is designed to be at least partially elastically compressible in a first direction, which first direction corresponds to the stacking direction when the battery cell separating element is arranged in the gap, wherein the battery cell separating element has a flexible first outer wall with a first inner side and a flexible second outer wall with a second inner side, wherein the first outer wall and the second outer wall are opposed to each other in the first direction such that the first inner side faces the second inner side, wherein the first outer wall and the second outer wall are at least partially interconnected in a circumferential manner at the edge side, and wherein there is an inner cavity of the battery cell separating element between the first outer wall and the second outer wall. Here, the battery cell separating element has an intermediate plate arranged between the first outer wall and the second outer wall, the intermediate plate dividing the inner cavity into at least a first spatial region and a second spatial region arranged side by side in the first direction, wherein the intermediate plate includes a first plate side facing the first inner side and a second plate side facing the second inner side, wherein the battery cell separating element has at least one elastic first support element arranged on the first plate side and at least one elastic second support element arranged on the second plate side, the elastic first support element elastically pressing the intermediate plate against the first inner side, and the elastic second support element elastically pressing the intermediate plate against the second inner side.

[0012] By means of two flexible outer walls which can be in direct contact with adjacent cells when arranged in the gap, very good heat dissipation of the cells can be provided in normal operation. At the same time, a good thermal barrier can be provided between two adjacent cells by means of the inner cavity between the two outer walls. It is now particularly advantageous that an intermediate plate is arranged between the two outer walls, which is elastically supported relative to the first outer wall and the second outer wall via an elastic support element. This allows particularly good expansion characteristics of the cell separator element. By means of the elastic properties of the support element and the flexible outer wall design, the cell separator element can be elastically compressed and can thus absorb the expansion forces very well and can adapt very well to the bulging geometry of the adjacent cells when bulging and retracting. Most importantly, by means of the intermediate plate and the elastic support by means of the support element, it can be additionally achieved that the cell separator element can be prevented from being completely flattened due to high expansion forces. In other words, by means of the support element and the intermediate plate, it can also be achieved that even in the case of high expansion pressure, the internal volume of the cell separator element, that is to say the volume of the inner cavity of the cell separator element, always has a specific minimum value. This in turn has the advantage of ensuring, on the one hand, that the thermal barrier that can be provided by the interior is maintained even in the case of high expansion pressures, and on the other hand, in the case of optional, more detailed below, but very advantageous liquid cooling, that the interior of the cell separator element remains efficiently flowable even when the expansion forces acting on the cell separator element are high, which allows for more efficient heat dissipation. Overall, the aspects of the best possible heat dissipation, the best possible insulation in the case of a thermal runaway of the cell, and particularly good expansion compensation can be advantageously combined in one cell separator element.

[0013] The two flexible outer walls can also be referred to as shells. In principle, the outer walls can be made of any material, for example, plastic and / or composite materials, in particular fiber composite materials and / or metal materials or any combination of the materials. Here, an embodiment in which the outer wall is made of a metal material, such as aluminum and / or steel and / or stainless steel, is very advantageous, because a particularly high thermal conductivity of the flexible outer wall can be provided. This has a positive effect on the heat dissipation during the operation of the battery pack. The outer wall can be provided in the form of an outer plate, in particular a preformed outer plate with a certain structural rigidity, or it can also be provided in the form of a film, which does not necessarily have to be designed to have structural rigidity or shape stability. However, a shape-stable outer plate design is preferred.

[0014] Through the thin-walled outer wall design, the outer wall can be constructed to have the desired flexibility for providing elastic compression characteristics. For example, the wall thickness of the corresponding outer wall, for example in the first direction, can be in the range of 0.1mm to 0.5mm, for example, about 0.25mm. The two outer walls can be at least partially, that is to say partially, connected to each other, especially fluid-tightly connected around the edge side. The two outer walls can also be completely connected to each other around the edge side, especially fluid-tightly connected, so that the inner cavity is completely enclosed between the two outer walls. In order to realize the optional input of the medium into the inner cavity and the discharge of the medium from the inner cavity, the battery cell separator element can be designed to have corresponding input connection parts and discharge connection parts, as described in more detail later. In this case, in addition to the parts where the input connection parts and the discharge connection parts are provided, the two outer walls are connected to each other around the edge side. For example, the two outer walls can be partially or completely welded to each other around the edge side and / or joined to each other in other ways, such as bonding and / or pressing and / or curling, etc.

[0015] The intermediate plate, and in particular at least one first supporting element and a second supporting element (which may also be referred to as supporting elements below) can in principle also be made of any material, such as a metal material and / or a plastic and / or a composite material and / or any combination thereof. In principle, the intermediate plate, and in particular also the elastic supporting element, can be made of a first material different from the second material used to make the outer wall. This hybrid structure of the cell separator element can also achieve more optimization possibilities in terms of heat dissipation and heat insulation. For example, the outer wall can be made of a metal material, while the intermediate plate with the supporting element is made of plastic or includes plastic. On the one hand, this can achieve particularly good heat dissipation of the cell, and on the other hand, it can achieve a good thermal barrier between two cells arranged adjacent to each other. But it is particularly advantageous and preferred that the outer wall and the intermediate plate, in particular including the supporting element, are made of the same material. This can achieve a simpler cell separator element construction and a simpler cell separator element design, and in addition simplifies the joint connection between the individual components, for example by means of welding. For example, the intermediate plate, and also the supporting element, can also be made of a metal material, for example, made of aluminum or steel or stainless steel. Furthermore, this allows particularly simple and advantageous production of the intermediate plate with the supporting element, as will be explained in greater detail below.

[0016] In this case, the outer wall preferably has an outer side which is at least largely or substantially completely flat, which enables flat contact with the respective adjacent battery cell.

[0017] The intermediate plate can simply be inserted into the inner cavity. That is, there does not have to be a materially bonded connection between the intermediate plate and the two outer walls. However, it is also conceivable that the intermediate plate is connected to the two outer walls in a materially bonded manner. For example, the intermediate plate can also be connected to the two outer walls at least partially around the edges. For example, the two outer walls and the intermediate plate located therebetween can be welded to each other around the edges, for example by a common weld seam. Other designs and joint connections between the components are also conceivable.

[0018] It is also preferred that the intermediate plate extends perpendicularly to the first direction over the entire inner cavity or at least almost over the entire inner cavity. Advantageously, the advantages of the intermediate plate and the supporting element arranged therein can be utilized over the entire surface of the cell separator element. In the initial state in which the cell separator element is not compressed, the base surfaces of the outer wall and the intermediate plate can be oriented and arranged substantially parallel to each other. There is a first spatial region of the inner cavity between the first outer wall and the intermediate plate, and a second spatial region of the inner cavity between the intermediate plate and the second outer wall. The two spatial regions are preferably substantially the same in size in terms of their respective volumes, as well as in terms of their dimensions perpendicular to the first direction. It is also preferred that the inner cavity is divided into only these two spatial regions by the intermediate plate. Here, "division" is understood as physically separating the two spatial regions at least partially, wherein the intermediate plate is arranged in the (imaginary) separation plane between the two spatial regions. However, the two spatial regions can be fluidically connected to each other. That is, the spatial regions do not have to be completely separated from each other in a fluid-tight manner in space. This is particularly not preferred, as described in more detail later. Thus, the division into the first spatial region and the second spatial region can also be understood only as theoretically dividing the inner cavity into two spatial regions.

[0019] For example, the support element can be designed as a spring element. At this time, many possible geometric shapes can be considered, and the support element can be designed according to these geometric shapes to provide this elastic effect. For example, the support element can be configured as a helical spring or a leaf spring or the like.

[0020] According to another very advantageous design of the present invention, the intermediate plate has at least one through-opening that completely penetrates the intermediate plate in a first direction, and the first spatial area and the second spatial area are fluidly connected to each other via the through-opening, in particular, at least one first support element and / or at least one second support element directly adjoins at least a part of the spatial area that limits the through-opening. This design also has a number of particularly great advantages: on the one hand, the through-opening that establishes a fluid connection between the two spatial areas can realize the possibility of more efficient flow through the inner cavity of the cell separator element at least for the case where the cell separator element should be flowed through by the coolant. This in turn can achieve a more efficient cooling effect of the cell separator element. However, in the case of an embodiment in which the cell separator element is completely closed and cannot be flowed through, a more uniform pressure distribution in the cell separator element can also be achieved, even if, for example, one of the two outer walls is pressed more strongly in the direction of the intermediate plate than the other outer wall due to the bulging of the adjacent cell. In addition, such a through-opening can be manufactured by a particularly advantageous and simple manufacturing method for manufacturing support elements. As described in more detail below, the through-opening can be manufactured, for example, as a partial punching bent from the intermediate plate. For example, for production, a base plate can be provided, and in order to produce such a support element, a portion extending along the U-shaped profile can first be punched out of the base plate. Subsequently, the base plate tongues surrounded by the punched-out U-shaped profile can be bent out of the plate plane of the base plate accordingly, for example by means of embossing or other methods, thereby producing a support element. The non-bent-out portion of the base plate then forms an intermediate plate with at least one through-opening accordingly. Subsequently, for example, a through-opening is also provided for each support element, to which the corresponding support element adjoins on the edge side. The tongues produced by the punching described can be bent alternately in opposite directions, more precisely bent out of the plate plane, thereby providing a first support element and a second support element, which then finally support the intermediate plate against, in particular elastically against, the first inner side and the second inner side.

[0021] It is therefore also very advantageous if the intermediate plate together with the supporting element is produced from a metallic material, since this allows particularly simple production of the supporting element by bending or curving.

[0022] According to another advantageous embodiment, at least one first support element and / or at least one second support element are designed integrally with the intermediate plate. This can be achieved, for example, in a simple manner by the above-described production method. This also enables a particularly fast, simple and cost-effective production of the intermediate plate with the support elements arranged there. Therefore, the support elements do not have to be subsequently fastened to the intermediate plate, for example by welding or gluing, etc., but can be produced, for example, by the above-described production method by stamping and bending together with the intermediate plate from the same starting component, i.e. the above-described base plate.

[0023] Therefore, another very advantageous design of the present invention is that the intermediate plate is located in the base plane, wherein at least one first support element and / or at least one second support element are designed as stamped elements bent out of the base plane. In particular, the support element can be constructed as a tongue-shaped stamped element. But in principle, any other geometric shape can also be conceived. The support element can be designed or will be designed as a stamped element so that the support element is also arranged at the intermediate plate with an end material lock. The contour surrounding the corresponding support element except the connection area can correspond to the stamped contour that has been punched out from the aforementioned base plate. Then, at least one support element can be manufactured in the following way: the support element is bent out of the base plane along a first direction, and the second support element is bent out of the base plane opposite to the first direction. Here, the bent section of the first support element and / or the second support element can, for example, have an arc shape, that is, an arc shape. This can provide a very good elastic effect. But in principle, the bent stamped element or support element can be designed to have an arbitrary curved shape.

[0024] At the same time, the spring rate provided by the support elements can be adjusted or suitably designed in a particularly simple manner by means of the size and / or the number of the support elements.

[0025] According to another advantageous design of the present invention, the cell separator element has a plurality of elastic first supporting elements arranged on the first plate side, spaced from each other and distributed on the first plate side, which form a first supporting element arrangement structure, and / or the cell separator element has a plurality of elastic second supporting elements arranged on the second plate side, spaced from each other and distributed on the second plate side, which form a second supporting element arrangement structure. Through this supporting element arrangement structure, a significantly more uniform supporting effect relative to the first inner side or the second inner side can be achieved. Thus, the elastic supporting effect can be provided on the entire surface of the cell separator element perpendicular to the first direction. Here, the corresponding supporting elements can not only be distributed on the corresponding plate side in the second direction perpendicular to the first direction, but also additionally or alternatively be distributed on the corresponding plate side in the third direction perpendicular to the first direction and the second direction. That is, the second direction can be defined perpendicular to the first direction, and a third direction that is also perpendicular to the second direction can also be defined. Here, a single first supporting element and / or a second supporting element can be arranged spaced from each other and distributed not only in the second direction but also in the third direction. For example, the support elements of a respective support element arrangement may be arranged in a regular pattern.

[0026] Here, the first support element comprises the at least one first support element. All other first support elements can be designed in the same manner as described above for the at least one first support element or the plurality of support elements. Here, the plurality of second support elements comprises the at least one second support element. Here, the other second support elements can be designed in the same manner as described above for the at least one second support element or the plurality of support elements.

[0027] According to another advantageous design of the present invention, the first support arrangement and / or the second support arrangement is designed so that the first region of the cell separator element has a first spring stiffness, which is greater than the second spring stiffness of the second region of the cell separator element. This has the great advantage that different expansion forces in different regions of the cell separator element can be taken into account. At the location where the adjacent cells exert typically greater expansion forces on the cell separator element, the cell separator element can be designed to have a correspondingly greater spring stiffness than in other regions. This can be achieved in a particularly simple and advantageous manner by correspondingly designing the corresponding support arrangement. In particular, it can be provided that one or more or all of the first support elements and / or the second support elements arranged in the first region of the intermediate plate have a greater spring stiffness than at least one or more or all of the first support elements and / or the second support elements arranged in the second region of the intermediate plate. Here, the first region of the intermediate plate can correspond to the first region of the cell separator element, and the second region of the intermediate plate can correspond to the second region of the cell separator element. In particular, the first region of the cell separator element can include the first region of the intermediate plate, and the second region of the cell separator element can include the second region of the intermediate plate. In this case, the corresponding regions, that is to say the first region of the cell separator element and the second region of the cell separator element, are arranged side by side in a direction perpendicular to the first direction. In this case, the first region of the intermediate plate and the second region of the intermediate plate are also arranged side by side perpendicular to the first direction. Advantageously, different spring stiffnesses of the cell separator elements can thus be provided in a plane perpendicular to the first direction. In this way, the support element can be simply designed to have spring stiffnesses of different magnitudes in the corresponding regions.

[0028] In addition or alternatively, it is also conceivable that in the first area of ​​the intermediate plate, more first support elements and / or second support elements are arranged per unit area than in the second area of ​​the intermediate plate. Therefore, the element density of the support elements can be greater in the first area than in the second area. Although the support elements are respectively configured to have the same spring stiffness, a greater total spring stiffness can be achieved in the first area than in the second area in a simple manner. In this example, the first area and the second area of ​​the intermediate plate can also be defined in the same way as described above. In addition, these two embodiments can also be combined with each other arbitrarily. For example, the support elements of the respectively identical support element arrangement structure can have different spring stiffnesses, and in addition, the support element density of the corresponding support element arrangement structure can also be locally different or varied. A variety of advantageous adaptation schemes are thus provided. An optimal bulge adaptation can thus be provided.

[0029] According to another advantageous design of the present invention, the first region of the cell separator element is the central region of the cell separator element in at least one second direction perpendicular to the first direction, and the second region of the cell separator element is the outer region of the cell separator element located outside the central region. This design is based on the understanding that the expansion force in the central region of the cell separator element in at least one second direction perpendicular to the first direction is usually significantly higher than that in the edge region of the cell separator element, that is, the edge region is located outside the central region. Thus, through this design, the cell separator element is particularly well adapted to the expansion forces that usually occur in the cell group.

[0030] For example, the spring stiffness of the cell separator element may be maximum in a central region of the cell separator element in the second direction. Here, the central region of the cell separator element includes the center of the cell separator element in the second direction. Optionally, the same may also be additionally applicable to a third direction defined perpendicularly to the first and second directions. The spring stiffness of the cell separator element may, for example, decrease radially outward from the central region. The support elements arranged side by side along the second direction may be constructed differently, that is, they may be designed to have different spring stiffnesses and / or have different distances from each other, wherein the support elements arranged side by side along the third direction may also be constructed differently, that is, they may be designed to have different spring stiffnesses and / or have different distances from each other. However, it is also conceivable that the spring stiffness decreases outward only along the second direction and in the opposite direction of the second direction from the central region, but remains constant outward along the third direction and in the opposite direction of the third direction, for example, at least in the center. The support elements arranged side by side along the third direction can be constructed, that is, designed to have the same spring stiffness and have the same distance from each other, while the support elements arranged side by side along the second direction can be constructed differently, that is, can be designed to have different spring stiffness and / or have the same distance from each other.

[0031] Thus, in this case, for example, it can also be provided that one or more or all first support elements and / or second support elements arranged at least in the second direction in the central region of the intermediate plate have a greater spring rate than at least one or more or all first support elements and / or second support elements arranged at least in the second direction outside the central region of the intermediate plate. Additionally or alternatively, it can be provided that more first support elements and / or second support elements are arranged per unit area in the central region of the intermediate plate at least in the second direction than in the region of the intermediate plate arranged at least in the second direction outside the central region of the intermediate plate. This design can be applied not only to the second direction but also, optionally, additionally or alternatively, to the third direction defined above.

[0032] According to another advantageous design of the present invention, the cell separator element has at least one coolant input connection for inputting a coolant into the inner cavity and at least one coolant discharge connection for discharging the coolant from the inner cavity. Thus, the cell separator element can be designed to be flowed through by a coolant, in particular a gaseous and / or liquid coolant, preferably a liquid coolant. In this case, the two outer walls are connected to each other on the edge side in such a way that the connection is fluid-tight. Thus, a more efficient cooling effect can be provided by the cell separator element. When the cell separator element is used in a battery or a motor vehicle, the cell separator element is correspondingly flowed through by such a coolant during cooling operation. Such a coolant can circulate in the cooling circuit of the motor vehicle. Accordingly, the cell separator element is connected to the cooling circuit. For example, the cell separator element can have only one coolant input connection and a coolant discharge connection. For example, it can be arranged on the same side in the second direction or the third direction of the cell separator element. Thus, a U-shaped flow through the cell separator element can be achieved. However, the two connecting parts can also be arranged on opposite sides of the cell separator element in the second direction or in the third direction. This enables the flow through the cell separator element from one side to the opposite side. Here, depending on the guidance of the coolant in the inner cavity, the flow can also be designed in a Z shape. Here, the support element can also be used as a flow guiding element in the inner cavity. Through this flow guiding element, a specific flow ratio can be adjusted in a targeted manner, and the cooling medium flowing through the inner cavity can be deflected or turned in a targeted manner.

[0033] It is also conceivable that the cell separator element comprises two coolant input connections and two coolant discharge connections. In this case, two of the four connections are arranged on one side of the cell separator element and the other two of the four connections are arranged on the opposite side of the cell separator element. This in turn can refer to a second or third direction. For example, two input connections can be arranged on the same side and two discharge connections can be arranged on the same side. However, it is also possible for one input connection and one discharge connection to be arranged on the same side. A design with two input connections and one discharge connection enables greater flexibility in terms of the flow possibilities of the cell separator element.

[0034] According to another advantageous design of the present invention, the inner cavity is fluid-tightly connected between the first outer wall and the second outer wall, in particular, a gaseous and / or liquid cooling medium is arranged in the inner cavity. Therefore, in this case, the inner cavity of the cell separator element should not be constructed to be flowed through or at least not flowed through by a coolant transported from the outside and discharged again. This can achieve a simpler design of the cell separator element. If the cell separator element is additionally filled with a cooling medium, such as a gaseous and / or liquid cooling medium, favorable cell separator element characteristics can be additionally achieved. For example, if the inner cavity is filled with air, a particularly good thermal barrier of the cell separator element can be provided between two adjacent cells. For example, if the cell separator element is filled with a liquid cooling medium, such as water or oil, on the one hand, a good thermal insulation effect can be provided through the high heat capacity, and good heat absorption can also be provided through the cell separator element. In addition, phase change materials and the like can also be accommodated in the inner cavity. In general, the cell separator element can also be used as a heating pipe, that is, a heat pipe.

[0035] Furthermore, it is preferred in this case that the cell separator elements are thermally and / or physically connected to the corresponding heat sink when installed in the battery module. This allows a particularly efficient heat dissipation from the cells via the cell separator elements towards the heat sink. For example, such a heat sink can be provided in the form of a cooling plate (which can also be referred to as a cooler) through which a cooling medium can flow. For example, the cell group can be placed on such a cooling plate. Furthermore, the cell group can be connected to the cooling plate via a thermal interface material, such as a heat conducting substance, in particular a hardenable heat conducting substance. Thermal and indirect physical contact between the cell separator elements and the cooling plate can also be established via the heat conducting substance.

[0036] According to another advantageous design of the present invention, the cell separator element has at least one layer, in particular a layer in the form of a fabric plate and / or a fiber plate, which is arranged in the first spatial region and / or the second spatial region. Preferably, this layer is also configured to be compressible in the first direction, in particular elastically compressible. Other advantageous properties of the cell separator element can be achieved by this additional layer or optionally also by two such additional layers (which can be arranged in the corresponding spatial region of the inner cavity, for example). Here, the layer can also have a plate-shaped shape. In addition, the layer can extend perpendicularly to the first direction over the entire inner cavity or spatial region in which the layer is arranged. For example, the propagation characteristics can be further improved by this layer. This layer can, for example, include glass fibers and / or aramid fibers and / or ceramic fibers or other fibers. Such fibers are particularly temperature-stable and provide additional barriers between the cells in the case of propagation. The support element can penetrate this layer in the first direction, or this layer can be directly attached to the inner side of the outer wall and the support element can be supported thereon.

[0037] Furthermore, the invention relates to a battery module for a motor vehicle, wherein the battery module comprises a cell separator element according to the invention or one of its embodiments.

[0038] In this case, in particular, the battery module can include a cell group having a plurality of cells arranged side by side in the stacking direction. For example, the cell can be designed as a lithium-ion cell. In particular, the cell can be, for example, a prismatic cell or a pouch cell. The cell group can be tensioned in the stacking direction by means of a tensioning device. A cell separator element according to the present invention or a cell separator element according to an embodiment of the present invention can be arranged between every two cells arranged adjacent to each other in the cell group. If the cell separator element is designed to be traversable by a coolant, the cell separator element can be connected to a common cooling supply line and / or a common cooling discharge line, in particular via the coolant supply connection and / or the coolant discharge connection already described above. A cell separator element or a plurality of cell separator elements can be limited in their extension or size perpendicular to the first direction to a gap between two cells arranged adjacent to each other in the cell group. Here, optional coolant supply connections and coolant discharge connections can extend from such a gap. Preferably, the corresponding coolant supply line and / or coolant discharge line are arranged outside the corresponding gap between each two battery cells arranged adjacent to each other. Preferably, the two flexible outer walls of the corresponding cell separator element are in surface contact with the adjacent battery cells of the battery cell group. In terms of its outer surface, the outer wall can correspond to the surface of the battery housing side of the battery cell to which the outer wall is adjacent. The outer wall can also be constructed to be slightly smaller than the corresponding battery housing surface of the adjacent battery cell. Preferably, the cell separator element is in surface contact with the adjacent battery cell. Here, the cell separator element can also be bonded to the adjacent battery cell or at least one of the adjacent battery cells. However, the cell separator element does not necessarily have to have a material-locked connection with one or more of the adjacent battery cells. This simplifies the disassembly of the battery module, for example in maintenance situations.

[0039] Furthermore, the present invention also relates to a battery having a battery module according to the present invention or one of its designs. Furthermore, such a battery may also include a plurality of such battery modules. For example, the battery may be designed as a high-voltage battery.

[0040] In addition, the battery can also include the above-mentioned heat sink, for example in the form of a cooling plate. The cooling plate can be provided, for example, by a housing bottom of the battery housing and / or by a housing cover of such a battery housing.

[0041] Furthermore, the invention relates to a motor vehicle having a battery module according to the invention or one of its embodiments or having a battery according to the invention or one of its embodiments.

[0042] For example, the motor vehicle may be configured as an electric vehicle. For example, the battery may be used as a power battery for a motor vehicle.

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

[0044] The present invention also includes improvements of the battery according to the invention, the battery module according to the invention and the motor vehicle according to the invention, which have the features already described in conjunction with the improvement of the cell separator element according to the invention. For this reason, the corresponding improvements of the battery according to the invention, the battery module according to the invention and the motor vehicle according to the invention will not be described again here.

[0045] 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

[0046] The embodiments of the present invention are described below. As shown in the figure:

[0047] Figure 1 A schematic perspective exploded view of a cell separator element according to one embodiment of the present invention is shown;

[0048] Figure 2 An embodiment of the present invention is shown Figure 1 A schematic perspective view of a cell separator element in FIG.

[0049] Figure 3 A schematic diagram of a battery module according to an exemplary embodiment of the present invention is shown in a cross-sectional view, the battery module having two battery cells and a cell separator element arranged between the battery cells;

[0050] Figure 4 A schematic diagram of a battery module according to an exemplary embodiment of the present invention is shown in an initial state where the battery cells are not swollen, the battery module having two battery cells and a cell separator element arranged between the battery cells; and

[0051] Figure 5 The battery cell is shown in a swollen state according to an embodiment of the present invention. Figure 4 Schematic diagram of the battery module. DETAILED DESCRIPTION

[0052] The embodiments described below 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.

[0053] In the figures, the same reference numerals respectively denote elements with the same function.

[0054] exist Figures 1 to 5 The coordinate system shown in is a Cartesian coordinate system. Preferably, the y direction shown corresponds to the aforementioned first direction. The x direction shown may correspond to the aforementioned second direction or third direction, and the z direction shown may correspond to the aforementioned third direction or second direction accordingly.

[0055] Figure 1 1 shows a schematic perspective view of a cell separator element 10 according to an exemplary embodiment of the present invention. The cell separator element 10 has a first flexible outer wall 12 and a second flexible outer wall 14. The first outer wall 12 comprises a first inner side 12a and a first outer side 12b opposite to the inner side 12a, in particular opposite in the y direction shown here, when the cell separator element 10 is arranged in a cell group 16 (see Figure 3 ), the y direction corresponds to the stacking direction. The second outer wall 14 also comprises a second inner side 14a (see also Figure 3 ) and a second outer side 14b opposite to the second inner side in the y direction. The outer walls 12, 14 are designed to be flexible, for example, they are designed as thin-walled preformed plates, for example made of metal material.

[0056] Furthermore, the cell separator element 10 comprises an intermediate plate 18 and elastic supporting elements 20a, 20b arranged at the intermediate plate. In general, the cell separator element 10 comprises at least one first supporting element 20a and at least one second supporting element 20b, the first supporting element supporting the first inner side 12a against, in particular elastically supporting, the intermediate plate 18 in the assembled state of the cell separator element 10, and the second supporting element supporting the second inner side 14a against the intermediate plate 18 in the assembled state of the cell separator element 10. For this purpose, the supporting elements 20a, 20b can directly contact the corresponding inner side 12a, 14a. In the present example, the cell separator element 10 comprises a plurality of first supporting elements 20a, 20b. Each of the supporting elements 20a, 20b comprises a connecting area 22a, 22b, via which the corresponding supporting element 20a, 20b is contact-connected with the plate 18. In particular, in the present example, the plate 18 and the supporting elements 20a, 20b are designed as one piece. In particular, the support elements 20a, 20b are designed as punched elements 24a, 24b. The punched elements can be provided in the following manner, that is, the respective support elements 20a, 20b are punched out of the base plate 26 along a circumferential contour, outside the region of their connection regions 22a, 22b, and the remaining tabs can then be bent out of the base plane of the base plate 26 in the y direction or in the opposite direction to the y direction for forming the support elements 20a, 20b. As a result, the first support element 20a is erected from the intermediate plate 18 in the y direction, while the second support element 20b is erected from the intermediate plate 18 in the opposite direction to the y direction. In this illustration, only the connection region 22a can be seen from the first support element 20a. The respective support elements 20a, 20b can extend in a curved manner in their direction from the connection regions 22a, 22b to the free ends of the respective support elements 20a, 20b that are respectively opposite. Advantageously, elastic properties of the support elements 20a, 20b can be achieved as a result.

[0057] Furthermore, the intermediate plate 18 comprises at least one through-opening 28 passing through it and in the present example each support element 20a, 20b comprises such a through-opening 28. When the support elements 20a, 20b are manufactured or constructed from the base plate 26, the through-opening can be automatically produced simultaneously.

[0058] The intermediate plate 18 can be configured together with the supporting elements 20a, 20b as an insert component, which is to be inserted or is inserted into the gap between the outer walls 12, 14, which in the assembled state of the cell separator element 10 close or surround the inner cavity 30 of the cell separator element 10. Optionally, the intermediate plate 18 can also be joined to the outer walls 12, 14, in particular joined by material locking, for example, welded to the outer walls.

[0059] Correspondingly, the first support element 20a forms a first support element arrangement 32a and the second support element 20b forms a second support element arrangement 32b. According to the support element arrangements 32a, 32b, the first support elements 20a and the second support elements 20b are arranged in rows and columns in a regular pattern, side by side and spaced apart from each other, not only in the x-direction but also in the z-direction. Other designs are also conceivable. In this case, the respective outer sides 12b, 14b of the outer walls 12, 14 can essentially correspond to the cell group 16 (see Figure 3 and Figure 4 ) of the adjacent battery cell 36 (see Figure 3 and Figure 4 ) of the housing sides 34 facing each other (see Figure 3 and Figure 4 ). Optionally, the outer sides 12b, 14b can be constructed to be slightly smaller than the corresponding cell sides 34. In terms of size and / or geometry, the intermediate plate 18 can also correspond to the size or geometry of the corresponding inner sides 12a, 14a of the outer walls 12, 14 or be constructed to be slightly smaller. The cell separator element 10 is designed essentially in a rectangular shape. The corresponding support element arrangement structures 32a, 32b extend in the x-direction and z-direction for the most part and preferably almost over the entire intermediate plate 18 in the x-direction and z-direction.

[0060] The interior 30 is divided into a first spatial region 30a and a second spatial region 30b by the intermediate plate 18 in the assembled state of the cell separator element 10. The respective support elements 20a, 20b then lie against the respective inner sides 12a, 14a of the outer walls 12, 14 and are in contact with their free ends.

[0061] The first outer wall 12 has two edge regions 12c that are opposite to each other in the z direction and two edge regions 12d that are opposite to each other in the x direction. The second outer wall 14 has two edge regions 14c that are opposite to each other in the z direction and two edge regions 14d that are opposite to each other in the x direction. In the assembled state of the cell separator element 10, the two outer walls 12, 14 are connected to each other via the edge regions 12c, 12d, 14c, 14d. In particular, the two outer walls are at least partially connected to each other around the edge side, in particular they are joined to each other in a fluid-tight manner. In the present example, the cell separator element 10 has four optional connection portions 38, 40 (see also Figure 2). Two of the four couplings 38, 40 can be used as coolant input couplings, and the other two couplings can be used as coolant discharge couplings. For example, the coupling 38 can be configured as a coolant input coupling, and the two couplings 40 can be configured as coolant discharge couplings, or vice versa. It is also possible that one of the couplings 38 and one of the couplings 40 are coolant input couplings, and the remaining two couplings 38, 40 are coolant discharge couplings.

[0062] It is thus advantageously possible to supply coolant to the inner chamber 30 and to discharge the coolant from the inner chamber again. The inner chamber 30 is thus constructed to be flow-through. The outer walls 12, 14 can be joined to one another in a fluid-tight manner in the edge region, for example welded to one another, except for the connecting regions 38, 40. In addition, the opening 28 in the intermediate plate 18 enables flow-through between the two spatial regions 30a, 30b of the inner chamber 30. The support elements 20a, 20b provide particularly advantageous expansion compensation properties. In addition, however, the support elements also ensure that the outer walls 12, 14 are always at a certain distance from one another and that the inner chamber 30 thus always includes a certain minimum volume. As a result, even in the event of severe expansion of the battery cell 36, the inner chamber 30 remains reliably flow-throughable by coolant and / or a heat barrier is reliably obtained.

[0063] Figure 2 Shown in assembled state Figure 1 Schematic perspective view of the cell separator element 10 in FIG. The connections 38 , 40 are merely optional. The outer walls 12 , 14 of the cell separator element 10 can also be joined to one another completely around the periphery in a fluid-tight manner in the edge region. Thus, for example, a coolant, for example a gaseous and / or liquid coolant with reference to standard conditions, that is, a temperature of 0° C. and a pressure of 1013.25 mbar, or a phase change material can be enclosed in the interior 30 .

[0064] Figure 3 A schematic diagram of a cell group 16 as part of a battery module 40 with two cells 36 shown by way of example is shown. In this example, the cells are designed as prismatic cells 36. In the gaps 42 between the cells 36, there is a cell separator element 10 according to an embodiment of the present invention. The cell separator element 10 can be constructed as described above, although it is not shown in detail here either. Here, the cell group 16 is shown in a cross-sectional view. Each cell 36 also has two cell electrodes 44, of which only one can be seen in this figure. In addition, each cell 36 has two cell electrodes 44, of which only one can be seen in this figure. Here, the two outer sides 12b, 14b of the outer walls 12, 14 are flatly abutted against the cell side 34 facing the interior.

[0065] Figure 4 A schematic diagram of a battery module 40 according to another embodiment of the present invention is shown. The battery module 40 can be designed substantially as described above. The battery module also exemplarily comprises a battery cell group 16 having two battery cells 36. In general, such a battery cell group 16 can include any number of battery cells 36, wherein preferably such a battery cell separator element 10 is arranged between every two battery cells 36 arranged side by side in the stacking direction y. In this case, the battery module 40 can be part of a battery 46. Such a battery 46 can include a plurality of battery modules 40. In addition, in Figure 4 Also shown is a cooling element 48, for example, in the form of a cooling plate 48, which can be traversed by a coolant, in particular by a liquid coolant, and during operation by a liquid coolant. Here, the cooling element 48 can be part of the battery 46. A plurality of battery modules 40 can be arranged on the same cooling element 48. But the cooling element 48 can also be part of the battery module 40. For example, each battery module 40 of the battery 46 can include an independent cooling element. The battery cell group 16 is connected to the cooling element 48 via a thermal interface material, such as a thermally conductive paste 50. This is also particularly applicable to the battery cell separator element 10 arranged between the battery cells 36. Here, the cooling element 48 is arranged below the battery cell group 16 in the z direction. In general, the cooling element 48 is arranged on any outer side of the battery cell group 16. Additionally or alternatively, the cooling element can be arranged above the battery cell group 16 in the z direction and / or in front of or behind the battery cell group 16 in the x direction. It is also possible to provide a plurality of cooling elements 48 that can be arranged on different outer sides of the battery cell group 16. Advantageously, a heat conduction path is thus provided from the battery cell 16 via the battery cell separator element 10, the thermally conductive paste 50 to the cooling element 48. In the cooling operation for cooling the battery cell 36, the cooling element 48 acts as a heat sink. Conversely, in this way, heating of the battery cell 36 can also be optionally achieved. Accordingly, in the heating operation, heat can also be transferred to the battery cell separator element 10 via the thermally conductive paste 50 through the cooling element 48 and from the battery cell separator element to the battery cell 36.

[0066] The heat input from the battery cells 36 into the cell separator elements 10 in the cooling mode is indicated by arrows 52, and the corresponding heat transfer from the cell separator elements 10 via the thermally conductive paste 50 to the cooling element 48 is indicated by arrows 54. This means that heat dissipation via the thermally conductive paste 50 to the cooling element 48 in the cooling mode can be advantageously provided.

[0067] In this example, the cell separator element 10 is designed so that it cannot be traversed by a coolant, but rather has an interior 30 which is completely enclosed by the outer walls 12, 14. This interior can be filled with air, for example. This air filling then serves as an insulating air layer 58. This is particularly advantageous in propagation situations. Despite the presence of this insulating air layer 58, very good heat dissipation to the cooling element 48 can also be provided by the direct contact of the cell sides 34 with the outer walls 12, 14 of the cell separator element 10.

[0068] Instead of the air layer 58 , the interior 30 can also be filled with a different cooling medium, for example water.

[0069] also, Figure 4 The battery cell 36 is shown in an initial state without swelling. Figure 5 The battery cell 36 is shown in a state where it swells in the y direction and in the opposite direction to the y direction. Figure 4 Schematic diagram of a battery module 40 or battery 46 in FIG. 1 , wherein the bulge is shown by way of example only for two cell sides 34 facing each other, but can be formed similarly on the opposite cell sides 34 ′. Figure 1 ) of the above-described intermediate plate 18 (see Figure 1 ) enables particularly advantageous expansion compensation. In particular, the corresponding support arrangements 32a, 32b (see Figure 1 ) can be designed so that different regions of the cell separator element 10 have different spring stiffnesses. For example, it is advantageous for such expansion compensation to be achieved by Figure 2 The central region Z shown by the dashed line in FIG. 1 has a spring stiffness greater than that of the outer region A outside the central region Z and / or next to the central region Z in the x-direction and / or the z-direction (see Figure 2 This can be achieved in a simple manner by different support element densities and / or different spring stiffnesses of the individual support elements 20a, 20b.

[0070] In general, the examples show how a cell separator element with a cooling function and variable compression characteristics can be provided by the present invention. By means of a separator plate made mainly of steel, the propagation of the cells can be reliably prevented and at the same time the expansion forces can be absorbed and the heat can be conducted away from the cells. The separator plate is also referred to as a cell separator element above. This is achieved by means of a separator plate made mainly of steel, which as a diaphragm consists of at least two layers, such as the aforementioned outer wall. The diaphragm can be filled or flowed through by different gases or fluids, whereby two characteristics, namely the spring stiffness and the insulation quality, can be adjusted. By means of an insert made mainly of steel, also referred to as an intermediate plate with a support element above, different stiffnesses and / or spring stiffnesses can be generated by means of different rib-shaped portions and / or embossed portions (which can be provided by the aforementioned support element). The propagation characteristics can be further improved by inserting another layer, such as a fabric and / or a fiberboard, between two metal layers, i.e. the outer walls.

Claims

1. A cell separator element (10) for being arranged in a gap (42) between two cells (36) arranged adjacent to each other in a stacking direction (y) of a cell group (16), wherein the cell separator element (10) is designed to be elastically compressible at least partially in a first direction (y), which first direction corresponds to the stacking direction (y) when the cell separator element (10) is arranged in the gap (42), wherein the cell separator element (10) has a first flexible outer wall (12) with a first inner side (12a) and a second flexible outer wall (14) with a second inner side (14a), - wherein the first outer wall (12) and the second outer wall (14) are opposite each other along a first direction (y), so that the first inner side (12a) faces the second inner side (14a), -in, The first outer wall (12) and the second outer wall (14) are at least partially connected to each other around the edge, wherein an inner cavity (30) of the cell separator element (10) exists between the first outer wall (12) and the second outer wall (14); It is characterized in that - the cell separator element (10) has an intermediate plate (18) arranged between the first outer wall (12) and the second outer wall (14), the intermediate plate dividing the inner cavity (30) into at least a first spatial region (30a) and a second spatial region (30b) arranged side by side along a first direction (y), - wherein the intermediate plate (18) comprises a first plate side facing the first inner side (12a) and a second plate side facing the second inner side (14a), -Wherein, the cell separator element (10) has at least one elastic first supporting element (20a) arranged on the first plate side and at least one elastic second supporting element (20b) arranged on the second plate side, the elastic first supporting element elastically supporting the intermediate plate (18) against the first inner side (12a), and the elastic second supporting element elastically supporting the intermediate plate (18) against the second inner side (14a).

2. The cell separator element (10) according to claim 1, characterized in that: The intermediate plate (18) has at least one through-opening (28) which completely penetrates the intermediate plate (18) in a first direction (y), and the first spatial area (30a) and the second spatial area (30b) are fluidically connected to each other via the through-opening, in particular, at least one first supporting element (20a) and / or at least one second supporting element (20b) directly adjoins at least a portion of an edge area which delimits the through-opening (28).

3. The cell separator element (10) according to any one of the preceding claims, characterized in that The intermediate plate (18) is located in a base plane, wherein at least one first support element (20a) and / or at least one second support element (20b) are designed as stamped elements (24a, 24b) bent out of the base plane.

4. The cell separator element (10) according to any one of the preceding claims, characterized in that The cell separator element (10) has a plurality of elastic first supporting elements (20a) arranged on a first plate side, spaced apart from each other and distributed on the first plate side, the first supporting elements forming a first supporting element arrangement structure (32a), and / or the cell separator element (10) has a plurality of elastic second supporting elements (20b) arranged on a second plate side, spaced apart from each other and distributed on the second plate side, the second supporting elements forming a second supporting element arrangement structure (32b).

5. The cell separator element (10) according to any one of the preceding claims, characterized in that The first support arrangement and / or the second support arrangement is designed so that the first region (Z) of the cell separator element (10) has a first spring stiffness which is greater than a second spring stiffness of the second region (A) of the cell separator element (10), in particular - wherein one or more or all of the first support elements (20a) and / or the second support elements (20b) arranged in the first region of the intermediate plate (18) have a greater spring rate than at least one or more or all of the first support elements (20a) and / or the second support elements (20b) arranged in the second region of the intermediate plate (18); and / or In the first region of the intermediate plate (18), more first supporting elements (20a) and / or second supporting elements (20b) are arranged per unit area than in the second region of the intermediate plate (18).

6. The cell separator element (10) according to any one of the preceding claims, characterized in that The first region (Z) of the cell separator element (10) is a central region (Z) of the cell separator element (10) in at least one second direction (x, z) perpendicular to the first direction (y), and the second region (A) of the cell separator element (10) is an outer region (A) of the cell separator element (10) located outside the central region.

7. The cell separator element (10) according to any one of the preceding claims, characterized in that The cell separator element (10) has at least one coolant supply connection (38, 40) for supplying a coolant into an interior (30) and at least one coolant discharge connection (38, 40) for discharging a coolant from the interior (30).

8. The cell separator element (10) according to any one of the preceding claims, characterized in that The inner chamber (30) is enclosed in a fluid-tight manner between a first outer wall (12) and a second outer wall (14), in particular wherein a gaseous and / or liquid cooling medium (58) is arranged in the inner chamber (30).

9. The cell separator element (10) according to any one of the preceding claims, characterized in that The cell separator element (10) has at least one layer, in particular in the form of a textile sheet and / or a fiber sheet, which is arranged in a first spatial region (30a) and / or in a second spatial region (30b).

10. A battery module (40) for a motor vehicle, comprising a cell separator element (10) according to any one of the preceding claims.

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