DE102022127133A1 - Battery module, battery and method for producing a battery for a motor vehicle - Google Patents

Abstract

The invention relates to a battery module (12) with a cell stack (16) with at least one battery cell (14), with a module base (12a) which delimits the battery module (12) on the underside with respect to a first direction (z), and a module housing (20) which has two end plates (18, 18') which delimit the cell stack (16) on both sides with respect to a second direction (x) which is perpendicular to the first direction (z). In this case, a module base extension component (40) is arranged on at least one first end plate (18, 18') on an outer side (18a, 18a') facing away from the cell stack (16), said module base extension component comprising an extension element (44) which projects from the outer side (18a, 18a') of the first end plate (18, 18') with respect to the second direction (y) and which is resiliently mounted on the first end plate (18, 18') in the first direction (z), wherein the extension element (44) has a lower side (44a) with respect to the first direction (z), which can be adjusted to the same height as the module base (12a) with respect to the first direction (z).

Description

The invention relates to a battery module for a motor vehicle, wherein the battery module has a cell stack with at least one battery cell, which comprises a cell bottom with respect to a first direction, a module base, which delimits the battery module on the bottom with respect to the first direction, wherein the cell bottom provides a part of the module base, a module housing, which has two end plates, which delimit the cell stack on both sides with respect to their second direction, which is perpendicular to the first direction, and a module width in a third direction. The invention also further relates to a battery for a motor vehicle and a method for producing a battery for a motor vehicle.

When manufacturing a battery for a motor vehicle, in particular a high-voltage battery, several battery modules are often arranged in a common overall battery housing. Such battery modules are placed on a housing base. This is often designed as a cooling base. In order to enable the best possible thermal connection to such a cooling base, the battery modules are thermally connected on their underside to the cooling base of the battery tray or the battery housing with a gap filler material, which is also referred to here as a thermally conductive compound or thermally conductive paste. As large a proportion of the module underside as possible is wetted with gap filler. Air inclusions in this gap filler layer have a detrimental effect on the thermal connection. The gap filler material is typically applied to the cooling base in a viscous state and then a corresponding battery module is placed on top of it and the gap filler material is then cured. Since the gap filler material leads to additional weight and costs and large gaps filled with gap filler material between the battery module and the cooling base lead to relatively poor thermal performance overall, it is desirable to keep the gap to be filled with this gap filler material as small as possible, but on the other hand, reliable wetting of the undersides of the battery modules in the desired areas should be ensured. The problem here, however, is that the components, especially the cooling base, but also the underside of a battery module, are subject to manufacturing-related tolerances that must be compensated for by the gap filler material. In addition, when the battery module is inserted into the battery housing, additional deformation of the cooling base can also occur, which also changes the geometry of the cavity between the battery module and the cooling base. This geometric change in the cooling base when inserting a battery module can also affect battery modules that have already been inserted into the housing if the gap filler has not yet hardened there. The gap geometry can also change accordingly. This can lead to unwanted air inclusions or these can occur later after a battery module has been installed.

The EN 10 2017 204 412 A1 describes a battery for a motor vehicle with a battery module, wherein a filling material is arranged in a space between a wall of the battery housing and a wall of a module housing of the battery module and this space is limited on at least one side by at least one limiting element. By providing such a limiting element, in particular a linear limiting element, it is possible to prevent an undesirable amount of filling material from escaping laterally from the space. However, such a limiting element also does not solve the problem of a possible subsequent change in the geometry of the cavity between the module underside and the housing base of the battery housing.

Furthermore, the EN 10 2018 209 104 A1 a method for producing a battery arrangement from a battery housing and a battery module, as well as a filling material and at least one tolerance compensation system, wherein the filling material is arranged on the bottom of the battery housing, the tolerance compensation system is arranged on the battery housing and/or battery module, wherein the battery module with the at least one tolerance compensation system is pressed in an insertion direction onto the bottom of the battery housing, wherein the filling material is pressed between the at least one battery module and the bottom of the battery housing. This tolerance compensation system can compensate for tolerances between the top of the module and a housing frame to which the battery module is to be attached with its top side of the module housing.

The object of the present invention is to provide a battery module, a battery and a method which enable the most reliable possible wetting of at least desired parts of the module underside with a thermally conductive compound when inserting the battery module into a battery housing and which enable tolerances to be compensated as well as possible.

This object is achieved by a battery module, a battery and a method having the features according to the respective independent patent claims. Advantageous embodiments of the The invention is the subject of the dependent claims, the description and the figures.

A battery module according to the invention for a motor vehicle has a cell stack with at least one battery cell, which comprises a cell underside in a first direction, a module base, which delimits the battery module on the underside in the first direction, the cell underside providing part of the module base, a module housing, which has two end plates, which delimit the cell stack on both sides in a second direction, which is perpendicular to the first direction, and a module width in a third direction. In this case, a module base extension component is arranged on at least one first end plate of the two end plates, which comprises an extension element that protrudes away from the first end plate in the second direction and the cell stack and that extends in the third direction over at least part of the module width of the battery module. Furthermore, the extension element is spring-mounted on the first end plate in the first direction and has a underside in the first direction, which can be adjusted to the same height as the module base in the first direction.

The invention is based on several findings: Firstly, battery cells have a pressure relief valve that allows the gas generated in the cell to escape in the event of a thermal runaway. There are now at least internal concepts with the approach of providing such a valve on the underside of the module or cell of the respective cells and providing degassing of the battery cell through the cooling base into a degassing channel provided for this purpose. In this case, a gap filler layer that is as continuous as possible between the underside of the module and the cooling base is desirable so that the escaping gas can be directed into the degassing channel as best as possible, since the gap filler also serves as a seal. The gap filler layer simultaneously prevents gas escaping from the battery cell from entering the interior of the battery housing through the gap between the underside of the module and the cooling base. However, it is not always easy to ensure this sealing property of the gap filler layer, especially in the edge areas of a battery module, more precisely in the area of the edge cells, which represent, for example, the first and/or last cell of a cell stack. It is precisely here that the distance between the degassing valve and the interior of the battery tray or the battery housing is particularly short. Accordingly, with reference to the second direction defined above, the gap filler layer extends from this degassing valve to the end of the battery module only a relatively short distance with reference to the second direction. It is therefore particularly advantageous to provide an above-mentioned module base extension component in the area of the outside of the first end plate, and preferably in a corresponding manner also on an outside of the second end plate, as a kind of end plate bracket. This module base extension component is arranged accordingly on the outside of the end plate and is adjustable so that its underside can be at the same height as the height of the module base. The module base extension component can, so to speak, extend the module base in and/or against the second direction. The gap filler layer or the thermally conductive mass can therefore also be distributed in this area beneath the module base extension component or between the underside of this module base extension component and a housing base. This extends the gap filler layer in relation to the second direction and thus also the distance that a gas escaping from the underside of an edge cell of the cell stack would have to travel in order to reach the interior of the battery housing. This means that the module base extension component can advantageously increase safety. However, it is particularly advantageous that this module base extension component, or more precisely the extension element, is spring-mounted in relation to the first direction. The reason for this is that when a battery module is inserted into the battery housing onto the gap filler that has already been applied, as described at the beginning, the geometry of this gap filled with gap filler between the underside of the battery module and the cooling base can subsequently change while the gap filler is still in a viscous state, especially if, after the battery module has been inserted, further battery modules are placed in the same battery housing onto the same cooling base, which can cause the cooling base to bulge downwards. This can have a negative effect on the degree of wetting of the undersides of the battery modules that are already in the battery box or battery housing. If the cavity between the underside of the battery module and the cooling base increases accordingly due to the cooling base bulging downwards, i.e. away from the battery module, the gap filler, for example, flows in and unwetted areas or air pockets or air channels are created, especially in the edge area of the battery module. It is precisely these air inclusions or air channels in the edge area of the battery module, especially in relation to the second direction, that can now be advantageously filled by the elastic or spring-loaded mounting of the extension element can be prevented or at least largely compensated for. Because the extension element is spring-mounted with respect to the first direction, the extension element can press downwards onto the gap filler layer or the thermally conductive compound. If, for example, during the deformation of the gap between the module base and the cooling base, more thermally conductive compound is drawn into a central area beneath the module base, or if the still viscous thermally conductive compound flows in, the extension element can move downwards accordingly due to the spring-mounted mounting. This may make the gap width between the underside of the extension element and the cooling base smaller, in particular, for example, smaller than the gap width between the rest of the module base and the cooling base; nevertheless, this reduced gap is then still reliably filled with thermally conductive compound and no air pockets are created, or even worse, air channels that could be particularly easily penetrated by a gas escaping from an edge cell. The extension element of the module base extension component, which is spring-mounted in the first direction, thus advantageously manages to combine several functions at the same time, namely, on the one hand, to increase the degree of wetting of the module underside with a thermally conductive compound, even if the geometry of the cavity filled with the thermally conductive compound is subsequently changed, and on the other hand, to significantly increase safety in connection with high-voltage batteries, since the module base extension component and its spring-mounted extension element can ensure reliable sealing of the gap between the battery module and the cooling base to the outside with thermally conductive compound, even if the geometry of the cavity is subsequently changed.

The at least one battery cell can generally be a prismatic battery cell and/or a pouch cell. The battery cell can be designed as a lithium-ion cell, for example. Furthermore, it is preferred that the cell stack not only has one such battery cell, but preferably several battery cells that are arranged next to one another in a stacking direction, wherein this stacking direction corresponds to the second direction defined here. Furthermore, in addition to the two end plates, the module housing can also have a clamping device in order to clamp the two end plates to one another and thus also to clamp the cell stack located between the end plates in the second direction. Optionally, the module housing can also have a module cover. The battery cells of a same cell stack can also be separated from one another in the stacking direction by cell separating elements. Accordingly, in addition to the cell underside of the at least one battery cell, the module base can also be provided by the corresponding undersides of the end plates and, if applicable, the undersides of the cell separating elements located between the cells.

The module base extension component can be arranged, for example, on an outside of the first end plate facing away from the cell stack, wherein the extension element protrudes from the outside of the first end plate outwards, i.e. away from the cell stack, with respect to the second direction. By definition, the underside of the extension element of the module base extension component is not to be regarded as part of the module base. The module base can, for example, be defined such that it extends to the extension element with respect to the second direction or to the respective outsides of the respective two end plates. As already mentioned above, it is also preferred that a second module base extension component is also arranged on the second end plate on the opposite side of the cell stack, e.g. also on an outside of this second end plate facing away from the cell stack.

This second module base extension component can be designed in the same way as the module base extension component that is arranged on the first end plate, as described above and below. Accordingly, for the sake of simplicity, only the module base extension component arranged on the first end plate is explained in more detail below. However, the described embodiments can also be implemented in the same way for the second module base extension component, which is preferably arranged on the outside of the wide end plate.

Furthermore, the extension element is preferably designed such that it protrudes from the outside of the first end plate by a length in the second direction, which is constant in the third direction. This enables a particularly simple design of the extension element and also enables a particularly uniform extension of the module base across the width of the battery module. This length can be in the millimeter range, but also in the centimeter range and is preferably less than 5 cm, in particular less than 4 cm, for example less than 3 cm and is preferably a maximum of 25 mm or 20 mm. A maximum length of 1 cm is also conceivable.

Furthermore, the extension element is spring-mounted in the first direction in such a way that its underside can be adjusted with or without additional force in relation to the first direction so that it is at the same height as the module base. The module base or its height can be defined by the lowest point of the first end plate in relation to the first direction or by an average height across all heights of the elements forming the module base, for example the respective cell undersides and the two end plates. The extension element is preferably spring-mounted in such a way that it can also be adjusted slightly higher than the module base in relation to the first direction, and accordingly also slightly lower.

Preferably, the spring-loaded mounting of the extension element is also designed such that the zero point position of the extension element, which its underside assumes without additional external force, i.e. apart from its own weight when the first direction is directed against the direction of gravity, is below the module base in relation to the first direction. This means that a corresponding pressure force from below on the underside of the extension element in relation to the first direction is required in order to set the underside to the same height as the module base. This ultimately means that when the battery module is arranged as intended in a battery housing on a thermally conductive mass, a certain contact force can be exerted on the thermally conductive mass by means of the underside of the extension element, in particular without having to accept very large gap heights in the area of the module base extension component.

In general, it can be provided that the extension element extends over at least 15 to 20 percent of the entire module width in relation to the third direction, for example also at least 30 percent or at least 40 percent, and is arranged centrally in relation to the module width in relation to the third direction. In a further advantageous embodiment of the invention, the extension element extends over a large part of the entire module width of the battery module in the third direction, in particular over the entire module width of the battery module in the third direction. This advantageously enables a module base extension over the entire width of the battery module. If the extension element does not extend over the entire module width, at least the middle of the battery module in relation to the third direction is covered by the extension element and the extension element extends from this middle in and against the third direction, preferably by essentially the same distance. The background to this is that the degassing openings or degassing valves of the cells described above are often arranged centrally in relation to the third direction. Especially in this area it is very advantageous to provide an additional protective barrier, provided by the module floor extension element.

In a further advantageous embodiment of the invention, the underside of the extension element is flat. This enables a particularly even distribution of the heat-conducting compound when inserting the battery module into the battery housing and also enables gaps that are as evenly high as possible between a cooling base, which is provided by the base of the battery housing, and the underside of the extension element.

According to a further advantageous embodiment of the invention, the at least one battery cell has a releasable cell degassing opening on its cell underside, through which gases can be led out of the battery cell in the event of thermal runaway of the battery cell. The releasable cell degassing opening can correspond to the degassing opening already mentioned or described above or to the degassing valve described. For example, such a releasable cell degassing opening can be designed as a predetermined breaking point in the cell housing, for example provided by a bursting membrane that bursts in the event of a certain excess pressure within the cell and thus clears the way for the gases to escape out of the cell. Furthermore, such a releasable cell degassing opening preferably opens passively. In other words, it is not a controllable opening. The releasable cell degassing opening preferably opens passively and depending on the pressure. A temperature-dependent opening would also be conceivable. It is particularly advantageous that the releasable cell degassing opening, which is also referred to as a vent opening or vent, is arranged on the underside of the battery cell, which provides the part of the module underside, in relation to the intended installation position in a motor vehicle. The invention shows its great advantages especially with cell degassing openings arranged on the underside, which is also referred to as the bottom venting concept, since, as described above, safety can be increased, since the module base extension component described can provide a reliable lateral seal of the gap between the module base and the housing base of the entire battery housing by means of a heat-conducting compound.

Furthermore, as also mentioned, it is preferred that this releasable cell degassing opening is arranged in the middle of the battery cell in relation to the third direction, more precisely in the middle of the cell underside. This cell degassing opening can also be located in the middle of the cell underside in relation to the second direction. If the cell stack comprises several battery cells, the releasable cell degassing openings are each located at the same location on a respective battery cell. These are, so to speak, on a line when viewed along the second direction. In relation to the third direction, these can take up 15 to 20 percent of the width of a respective battery cell in relation to the third direction.

In a further very advantageous embodiment of the invention, the module base extension component has a spring for the resilient mounting of the extension element, in particular a leaf spring and/or disc spring and/or a spiral spring and/or a bent sheet, and/or the module base extension component has a spring element made of an elastically deformable solid material, in particular of a foam and/or a rubber. The resilient mounting of the extension element can therefore be implemented in a wide variety of ways. The examples given do not represent an exhaustive list, but other elements for the resilient mounting of the extension element can also be considered. The design of the resilient mounting with a spring is particularly simple, for example a leaf spring or disc spring or a spiral spring. Combinations of various such springs or spring elements can also be considered in order to provide the resilient mounting. The use of a spring has the advantage that the spring holder can be very easily selected as desired due to the large number of springs known from the prior art. To achieve the spring-loaded mounting, such a spring or spring element can also be located between the extension element and, for example, a support element or support flange fixed to the end plate. If the extension element is moved upwards in relation to the first direction in the direction of this support flange, the spring or spring element is compressed accordingly. The spring or spring element counteracts this compressive force with a suitable spring force according to the selected spring hardness.

In a further advantageous embodiment of the invention, the battery module has at least one guide rail running in the first direction on the first end plate, in particular on its outer side facing away from the cell stack, through which the module base extension component can be guided when the module base extension component is moved in and against the first direction. This stabilizes the movement of the module base extension component in and against the first direction. A movement of the module base extension component in and against the third direction and in and against the second direction is therefore not possible or hardly possible or only possible with extremely little play.

In a further advantageous embodiment of the invention, the module base extension component has a connection component which is arranged on the extension element so as to be immovable relative to it, in particular is formed integrally with it, wherein the connection component has a contact side which faces the outside of the first end plate facing away from the cell stack and which is aligned substantially perpendicular to the underside of the extension element. Optionally, the contact side can rest against the outside of the first end plate and/or be sealed against it.

The connection component can, for example, be designed in one piece together with the extension element as an angle or angled rail. This angled rail can, for example, have an L-shaped geometry in a cross section perpendicular to the third direction and can be designed to be essentially translationally invariant in terms of its cross-sectional geometry in or against the third direction. The extension element is designed to be immobile relative to this connection component. For example, the extension element is rigidly attached to the connection component and cannot be rotated relative to it, for example. For example, the extension element can also be welded or glued to the connection component. A one-piece design is very advantageous. This connection component has the advantage that if the underside of the extension element is lower than the module base, no gap is formed between the module base and the extension element. This advantageously means that heat-conducting compound cannot, or at least cannot easily, get into gaps between the module base extension component and, for example, the first end plate. It is therefore very advantageous if the contact side lies as close as possible to the first end plate. Since the heat-conducting compound can often be a very viscous mass, even small gaps between the contact side and the first end plate or its outside can be tolerated. Optionally, a seal can also be provided in this area. This is designed in such a way that relative movement between the contact side and the outside of the first end plate is possible, in particular a translational relative movement in and/or against the first direction.

Furthermore, it is preferred that the module base extension component or the extension element and in particular also the connection component rigidly connected thereto can be moved exclusively in and/or against the first direction in a purely translational manner relative to the first end plate. This can be ensured by the at least one guide rail described above.

Furthermore, the invention also relates to a battery for a motor vehicle, which has a battery module according to the invention or one of its embodiments.

The advantages described for the battery module according to the invention and its configurations therefore apply equally to the battery according to the invention. The battery is preferably designed as a high-voltage battery for the motor vehicle. In addition, the battery can also comprise several battery modules according to the invention or several battery modules according to embodiments of the invention.

In a further advantageous embodiment of the invention, the battery has a battery housing with a housing base that delimits the battery downwards with respect to the first direction. Furthermore, the battery module is preferably arranged in the battery housing with the module base facing the housing base, in particular with several battery modules arranged in the battery housing. The advantages described above arise precisely with this arrangement.

In a further advantageous embodiment of the invention, a hardened heat-conducting compound is arranged between the housing base and the module base, and at least partially between the housing base and the underside of the extension element. Advantageously, the path through which gases escaping from a battery cell have to penetrate laterally in order to reach the interior of the battery housing can be significantly extended by means of the extension element. This case is therefore all the less likely and safety can be significantly increased.

The thermally conductive compound represents the previously mentioned gap filler or gap filler material. The thermally conductive compound can also be referred to as thermal interface material. This thermally conductive compound can completely or partially fill the space between the module base and the housing base of the battery housing. For example, an area directly below the releasable cell degassing openings of the battery cells of the cell stack can be kept free of thermally conductive compound. This facilitates the escape of gases from the underside of thermally continuous cells.

Furthermore, the invention also includes a motor vehicle with a battery according to the invention or one of its embodiments.

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

Furthermore, the invention also relates to a method for producing a battery for a motor vehicle, wherein a battery housing with a housing base is provided, a battery module is provided and a thermally conductive compound in the viscous state is applied to the housing base in an arrangement area of the housing base assigned to the battery module. Furthermore, the battery module is placed on the thermally conductive compound in the arrangement area and the battery module is pressed in the direction of the housing base after being placed on. In this case, a battery module according to the invention or one of its embodiments is provided as the battery module, which is placed on the thermally conductive compound in such a way that the module base faces the housing base. The module base extension component included in the battery module according to the invention enables a significantly more uniform wetting of the module base without air inclusions or air channels. In addition, safety can be increased as described above, since the spring mounting enables reliable sealing on the side of the battery module by means of the thermally conductive compound.

The advantages described for the battery module according to the invention and its embodiments therefore apply equally to the method according to the invention.

The housing base of the battery housing can be designed as a cooling base, for example. Such a cooling base can be designed with cooling channels, for example, through which a cooling medium, for example cooling water or the like, preferably a cooling liquid, flows during operation, in particular in a closed cooling circuit. Accordingly, a coolant can be circulated through the housing base.

The invention also includes further developments of the method according to the invention, the features times, as have already been described in connection with the developments of the battery module according to the invention and the battery according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.

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

• 1 eine schematische Darstellung eines Teils einer Batterie mit einer Vorstufe eines Batteriemoduls gemäß einem Ausführungsbeispiel der Erfindung; und
• 2 eine schematische Darstellung eines Teils einer Batterie mit einem Batteriemodul gemäß einem Ausführungsbeispiel der Erfindung.

Exemplary embodiments of the invention are described below.

• 1 a schematic representation of a part of a battery with a precursor of a battery module according to an embodiment of the invention; and
• 2 a schematic representation of a part of a battery with a battery module according to an embodiment of the invention.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the components of the embodiments described each represent individual features of the invention that are to be considered independently of one another and which also develop the invention independently of one another. Therefore, the disclosure should also include combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

In the figures, identical reference symbols designate functionally identical elements.

1 shows a schematic representation of a part of a battery 10 with a precursor of a battery module 12 according to an embodiment of the invention. In this example, the battery module 12 comprises several battery cells 14, which are arranged next to one another in a stacking direction x and thus form a cell stack 16. The cell stack 16 is delimited in and against the x direction by an end plate 18. The end plate 18 can be understood as part of a module housing 20. The end plate 18 has an outer side 18a. In this example, the battery module 12 is arranged in a battery housing 22, of which only the housing base 24 is shown here. The battery cells 14 also have cell degassing openings 25 that can be opened on their respective cell undersides 14a. If a battery cell 14 breaks down thermally, this cell degassing opening 25, which can be designed as a bursting membrane, for example, can be passively released, allowing gas to escape from the battery cell 14, as shown in 1 shown using the right battery cell 14. Ideally, this escaping gas 28 should be guided through the bottom 24 of the housing into a degassing channel 30. This degassing channel 30 can be limited on the underside by a channel wall 32. This allows the escaping gas 28 to be diverted from the battery housing 22 and from the battery 10 as a whole.

In order to continue to thermally connect the cells 14 as well as possible to a cooling device 26 provided by the housing base 24, a thermally conductive compound 34 is arranged between the module base 12a, which is partially provided by the cell undersides 14a of the cells 14, and the cooling base 26. This thermally conductive compound 34 also seals the gas flow 28 emerging from a cell 14 from the interior 36 of the battery housing 22 in the event of a thermal event. The edge cell 14b of a module 12 is particularly important here, since the distance between the degassing valve 25 and the interior 36 of the battery tray 22 is particularly short here.

In order to increase the distance between the degassing valve 25 and the interior space 36, it is provided in the present case to attach a so-called end plate bracket 38 to the battery module 12, in particular to the outer side 18a of the end plate 18, which can in particular also be regarded as part of an aforementioned module base extension component 40.

If such an end-plate bracket 38, for example in the form of an angled rail as in 1 shown, are firmly and immovably attached to the battery module 12, for example to the end plate 18, this could still lead to problems. For example, after the battery module 12 has been pressed in, air pockets 42 could form, which are also referred to as meanders due to their partially winding channel-like course, and these could reduce the sealing function of the component.

In 1 is shown by way of example how, due to such an air inclusion 42, the lateral sealing function of the heat-conducting mass 34 is no longer provided in the event of a thermal runaway of the battery cell 14b, so that the gas flow 28 or at least a part of it does not reach the degassing channel 30, but is laterally between between the underside 12a of the battery module 12 and the cooling base 26 and can thus reach the interior 36 of the housing 22.

This can now be advantageously prevented by the further developments described below, especially the mentioned end plate bracket 38, or the risk can at least be significantly reduced. This will now be shown using 2 explained in more detail.

2 shows a schematic representation of a battery 10` or a part thereof according to an embodiment of the invention. The battery 10` and in particular the battery module 12 and the battery housing 22 or its base 24, which in turn is designed as a cooling base 26, can be 1 described, except that the end plate bracket 38 is now designed to be movable.

In this example, the battery module 12 has two end plates 18, 18' which delimit the battery module 12 or the cell stack 16 on both sides in the x-direction and which are part of a module housing 20. A first end plate is designated 18 and an opposite second end plate is designated 18'. In the present case, a module base extension component 40 is arranged on both end plates 18, 18'. These two module base extension components 40 can be designed in the same way, so that only one of these two components 40 is described in more detail below. Such a module base extension component 40 can in turn 1 described end plate bracket 38. This is composed, for example, of an extension element 44 and a connecting component 46. The extension element 44 and the connecting component 46 are arranged rigidly or not movable relative to one another and can, for example, also be formed in one piece. In addition, these two components 44, 46 are arranged at a right angle to one another. The extension element 44 has a bottom side 44a. The connecting component 46 has a contact side 46a which faces the outside 18a, 18a` of the end plate 18, 18`.

The extension element 44, in this case including the connection element 46, is now advantageously mounted spring-loaded in the z-direction. This means that the underside 44a of the extension element 44 in particular can move in and against the z-direction. In addition, a restoring force can be generated by the spring-loaded mounting by moving the extension element 44 in the z-direction. In the present example, the spring-loaded mounting 48 is implemented by a spring 50, such as a spiral spring, a leaf spring, a disc spring or the like. However, such a spring-loaded mounting 48 can also be designed in any other way, for example by an elastically deformable solid material, for example a foam, a rubber element, and so on. In addition, in the present example, one or more guide rails 52 are also provided on the outside of the corresponding end plate 18, 18'. The movement of the end plate bracket 38 can thus take place in and against the z-direction guided by these guide rails 52. In other words, in this case the end plate bracket 38 is mounted on the one hand in guide rails 52, which enable movement of the component, i.e. the end plate bracket 38, along the vertical axis, i.e. parallel to the z-direction shown here, but not in other directions. In addition, an additional component is introduced as part of the module base extension component 40, namely the component for spring mounting 48, which takes on a spring effect along the vertical axis, which is represented here by the z-axis. The end plate bracket 38 can thus advantageously be equipped with spring properties or be structurally designed. This advantageously reduces the meandering below the end plate bracket 38 during the assembly process of the battery 10'. This ensures the best possible sealing function, despite dimensional deviations due to manufacturing and component-related dimensional deviations.

As in 2 As can be seen, for example, when producing the battery 10', the thermally conductive compound 34 can first be applied to the cooling base 26 and then the battery module 12 can be placed on top of it from above, i.e. against the z-direction. The battery module 12 can then be pressed slightly against the thermally conductive compound 34 in the opposite direction to the z-direction, i.e. in the direction of the cooling base 26. The spring-loaded mounting 48 of the end plate bracket 38 is designed such that the underside 44a of the extension element 44 can be adjusted in the z-direction to the height of the underside 12a of the battery module 12. In this setting, the spring-loaded mounting 48 is preferably in an at least slightly compressed or tensioned state, so that a certain contact force is exerted on the thermally conductive compound 34 by the underside 44a of the end plate bracket 38 in the direction of the latter. If, for example, another battery module 12 is subsequently placed and mounted on the same cooling base 26, this can lead to a geometric change in the cavity between the underside 12a of the module 12 and the cooling base 26. For example, the cooling base 26 can curve slightly further downwards, which can, for example, allow more of the still viscous heat-conducting compound 34 to be drawn into the central area in relation to the x-direction under the module 12. This would usually chally to the 1 described formation of air inclusions 42. Because this further flow of the gap filler 34 can now be at least partially compensated by the pressing or further downwards pressed end plate bracket 38, the air inclusions 42 can be avoided. The underside 44a of the extension element 44 can therefore be moved a little further downwards simply by the spring force when the gap filler 34 continues to flow, whereby air can be successfully displaced or prevented from entering. The sealing function can thus be reliably ensured, especially in the lateral area below the end plate bracket 38, which is provided by the gap filler material 34 located there in the gap. In the event of a thermal event in an edge cell 14b, the gas 28 escaping from its releasable degassing opening 25 can therefore be reliably guided into the degassing channel 30 located below the cooling base 26. Penetration into the interior 36 of the housing 22 can be reliably prevented. The distance between the underside 12a and the cooling base 26 can also be 1 mm on average, for example averaged over the underside 12a of the module 12, but can deviate locally and lie between 0.3 mm and 1.4 mm in the z-direction.

Overall, the examples show how the invention can provide a resilient end plate bracket for battery modules with bottom venting concept.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102017204412 A1 [0003]
• DE 102018209104 A1 [0004]

Claims (10)

Battery module (12) for a motor vehicle, comprising: - a cell stack (16) with at least one battery cell (14) which comprises a cell bottom (14a) with respect to a first direction (z), - a module base (12a) which delimits the battery module (12) on the bottom with respect to the first direction (z), wherein the cell bottom (14a) provides a part of the module base (12a); - a module housing (20) which has two end plates (18, 18') which delimit the cell stack (16) on both sides with respect to a second direction (x) which is perpendicular to the first direction (z); and - a module width in a third direction (y); characterized in that - on at least a first end plate (18, 18') of the two end plates (18, 18') a module base extension component (40) is arranged, which comprises an extension element (44), - which projects away from the first end plate (18, 18') with respect to the second direction (y) and the cell stack (16) and - which extends in the third direction (y) over at least part of the module width of the battery module (12), - wherein the extension element (44) is resiliently mounted on the first end plate (18, 18') in the first direction (z), and - wherein the extension element (44) has a lower side (44a) with respect to the first direction (z), which can be adjusted to the same height as the module base (12a) with respect to the first direction (z). Battery module (12) after Claim 1 , characterized in that the extension element (44) extends over the entire module width of the battery module (12). Battery module (12) according to one of the preceding claims, characterized in that the underside (44a) of the extension element (44) is flat. Battery module (12) according to one of the preceding claims, characterized in that the at least one battery cell (14) has on its cell underside (14a) a releasable cell degassing opening (25) through which gases (28) can be led out of the battery cell (14) in the event of thermal runaway of the battery cell (14). Battery module (12) according to one of the preceding claims, characterized in that the module base extension component (40) for the resilient mounting (48) of the extension element (44) has a spring (50), in particular a leaf spring and/or disc spring and/or a spiral spring and/or a bent sheet, and/or a spring element made of an elastically deformable solid material, in particular made of a foam and/or a rubber. Battery module (12) according to one of the preceding claims, characterized in that the battery module (12) has on the first end plate (18, 18'), in particular on its outer side (18a, 18a') facing away from the cell stack (16), at least one guide rail (52) running in the first direction (z), through which the module base extension component (40) can be guided when the module base extension component (40) is moved in and against the first direction (z). Battery module (12) according to one of the preceding claims, characterized in that - the module base extension component (40) has a connection component (46) - which is arranged on the extension element (44) immovably relative to the latter, in particular is formed integrally with the latter, - wherein the connection component (46) has a contact side (46a) which faces an outer side (18a, 18a') of the first end plate (18, 18') facing away from the cell stack (16) and which is aligned substantially perpendicular to the underside (44a) of the extension element (44), - in particular wherein the contact side (46a) rests against the outer side (18a, 18a') of the first end plate (18, 18') and/or is sealed relative to the latter. Battery (10`) for a motor vehicle with a battery module (12) according to one of the preceding claims, characterized in that the battery (10`) has a battery housing (22) with a housing base (24) which delimits the battery (10`) downwards with respect to the first direction (z), wherein the battery module (12) is arranged in the battery housing (22) with the module base (12a) facing the housing base (24), in particular wherein several battery modules (12) are arranged in the battery housing (22). Battery after Claim 8 , characterized in that a hardened heat-conducting compound (34) is arranged between the housing base (24) and the module base (12a), and at least partially between the housing base (24) and the underside (44a) of the extension element (44). Method for producing a battery for a motor vehicle, comprising the steps of: - providing a battery housing (22) with a housing base (24); - providing a battery module (12); - applying a heat-conducting compound (34) in the viscous State on the housing base (24) in an arrangement area of the housing base (24) assigned to the battery module (12); - placing the battery module (12) on the heat conducting mass (34) in the arrangement area; and - pressing the battery module (12) in the direction of the housing base (24) after placing it; characterized in that the battery module (12) is a battery module (12) according to one of the Claims 1 until 7 which is placed on the thermally conductive mass (36) in such a way that the module base (12a) faces the housing base (24).

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