Battery for vehicles, and method for producing a battery of this type

Abstract

The invention relates to a battery (1) having a plurality of battery cells (10) which are arranged in a housing and are electrically connected to one another, wherein intermediate spaces (20) are formed between adjacent battery cells (10) and between the battery cells (10) and the housing, and having at least one reinforcing device (30) for reinforcing the battery (1), wherein the at least one reinforcing device (30) is arranged in one of the intermediate spaces (20) of the battery (1) and comprises an elongate, radially expandable, spreadable or compressible reinforcing body (50) and a spreading means (40), wherein the spreading means (40) is designed such that it acts on the reinforcing body (50) and expands, spreads or compresses same such that the reinforcing body (50) rests in a force-fitting manner against the respective circumferential surface of the adjacent battery cells (10) and / or against the respective inner wall of the housing.

Description

[0001] Mercedes-Benz Group AG

[0002] Battery for vehicles and methods for manufacturing such a battery

[0003] The invention relates to a battery for vehicles, comprising a plurality of battery cells connected in parallel and / or in series, which are arranged in a housing of the battery, and to a method for manufacturing such a battery.

[0004] Storage batteries, also known as batteries or accumulators, are commonly used to provide electrical energy. To power electric vehicles, electrical energy at a relatively high voltage, for example, 60 to 400 volts, is required, and the storage batteries used for this purpose are also called high-voltage storage systems or traction batteries. Newer electric vehicles even utilize 800-volt drive technology and employ an 800-volt battery. Today, such high-voltage storage systems are generally not monoblocks but rather modular, constructed from a large number of battery cells. Depending on the cell format, the number of battery cells can range from three to four digits. The number of battery cells used is also directly related to the range of the electric or hybrid vehicle and thus its attractiveness to the user.In practice, cylindrical cells, prismatic battery cells, especially flat cells, or so-called pouch cells are used as battery cells for high-voltage storage systems.

[0005] Typically, battery cells within the battery are cooled by a cooling plate located at the bottom. This cooling plate can cover the entire surface or only parts of the battery compartment. The battery cells are usually bonded to the cooling plate using a thermally conductive adhesive, thus securing them within the battery. In the case of cylindrical battery cells, it is common practice to fill the spaces between the cells with a potting compound.

[0006] US patent 2020 / 0099022 A1 discloses a battery module with two frame halves in which wedge elements and bolts are integral components of the respective frame walls. When the frame halves are joined, the molded-in bolts are inserted into the openings of the wedge elements, causing them to expand elastically and clamp the battery cells in place. Separate, replaceable expanding elements are not provided.

[0007] CN 207 217 632 U, DE 102014 206 813 Al, DE 102020 121498 Al and DE 102015 221 269 Al reveal further noteworthy structures for holding battery cells.

[0008] Examples of this include DE 102016 214640 Al and DE 102020 115 924 Al, which disclose a battery module for a motor vehicle battery in which the cavities between the battery cells and the battery module housing are filled with a potting compound made of an electrically insulating material. A disadvantage is that the potting compound and / or the adhesive, in particular thermally conductive adhesive, permanently bonds the battery cells together. Due to this inseparable, material-bonded connection between the battery components and the battery cells, it is extremely difficult to recycle such batteries. Another major disadvantage is that the adhesive and / or the potting compound are often exposed to large temperature fluctuations, sometimes between -20°C and +60°C, which can lead to cracks in the adhesive and / or the potting compound.Accurate dosing of the potting compound and cleanly filling the potting compound into the battery module also repeatedly pose major problems for manufacturers.

[0009] Furthermore, DE 10 2013 020369 A1 discloses a battery module that can be used to store electrical energy and comprises at least one cylindrical cell, wherein the cylindrical cells are held by an upper and a lower retaining plate. To hold the cylindrical cells in position, the retaining plates each have larger recesses for the cylinder of a cylindrical cell and smaller recesses for the pole geometry of a cylindrical cell. A major disadvantage is that the battery cells are only held at their end faces and can be damaged by strong forces.

[0010] From DE 102007049358 A1, a battery pack is known comprising a housing and at least one battery cell, as well as means for compensating for tolerances of the battery cell. The tolerance compensation means include at least one elastic expanding element, which is arranged in a gap between at least two battery cells and / or between the single battery cell and the housing, and which is made of an elastomeric material. The elastic expanding element is formed in one piece and has four side walls adapted to the contour or circumferential surface of the battery cells. When the expanding element is inserted into the gap, the battery cells adjacent to the gap are pressed apart. Although the tolerance compensation means allow the battery cells to be accommodated in the housing with essentially no play, despite their sometimes considerable dimensional tolerances, the tolerance compensation means are only partially suitable for stiffening the battery pack.

[0011] Furthermore, DE 102016 206463 Al relates to a battery cell module comprising a first, lower distribution plate and a second, upper distribution plate, with a plurality of battery cells arranged between them. While a plurality of cooling elements in the form of cooling tubes project from the lower distribution plate, a plurality of clamping fingers, preferably with a hollow core, are arranged on the second distribution plate, projecting from the second distribution plate towards the first distribution plate. The clamping fingers can be cast as a single unit with the second distribution plate or manufactured as a separate component. In this case, the cooling elements have a coating of thermally conductive, elastic material, such as silicone, which has a fourfold concave cross-section and an outer contour adapted to the shape of a battery cell.To ensure optimal contact between the battery cells and the cooling elements, clamping fingers engage in an empty space between four battery cells, pressing them sideways towards the cooling elements. The free end of each clamping finger can be designed as a double-slotted cone end, which, when the battery cell module is assembled, engages a spreading mandrel located on the first distribution plate. When the clamping finger and spreading mandrel are brought together, the cone end expands, forcing apart the ends of the battery cells facing the first distribution plate. A disadvantage is that the spreading force is not transmitted along the entire length of the clamping finger, but only in the area of ​​the double-slotted cone end. Furthermore, the manufacturing of the elongated clamping finger with its special end section is relatively complex.

[0012] Finally, DE 102014 217425 A discloses a battery module comprising a housing, a plurality of prismatic battery cells arranged in the housing, and a clamping device. The clamping device has a flexible container made of a film, which is shaped like a bubble, bag, pillow, drum, or cylinder and encloses an interior space of variable volume. A filling medium, such as a fluid like water or silicone oil, a gas or inert gas like nitrogen, argon, or krypton, or a gel, is introduced to clamp the device. A disadvantage is that the thin film wall of the container can be easily damaged, which can cause the filling medium to escape into the battery module and the clamping device to lose its clamping force continuously or abruptly.

[0013] The task is therefore to provide a battery, especially for vehicles, that overcomes the disadvantages of the current state of the art. The battery should be as resistant as possible to external forces. Furthermore, it should be recyclable, have a simple design, and be cost-effective to manufacture.

[0014] This problem is solved according to the invention by the battery according to claim 1 and the method for producing such a battery according to claim 13.

[0015] Generally speaking, there are various types of battery cells. In the context of the invention, battery cells preferably refer to battery cells designed as cylindrical cells, hexagonal battery cells, prismatic battery cells, in particular flat cells, or as so-called pouch cells. A typical cylindrical cell preferably has an elongated, cylindrical cell body, which has a positive pole at one end and a negative pole at the opposite end.

[0016] The batteries according to the invention are particularly suitable for vehicle batteries of all types, but also as energy storage devices for photovoltaic systems, and comprise a plurality of battery cells which are arranged in a housing of the battery and electrically connected to one another, wherein gaps are formed between adjacent battery cells and between the battery cells and the housing, and at least one stiffening device for stiffening the battery, wherein the at least one stiffening device is arranged in one of the gaps of the battery and comprises an elongated stiffening body that can be expanded in the radial direction and a corresponding expanding element. The stiffening body has a recess extending in the longitudinal direction of the stiffening body, preferably bore-hole or blind-hole-like, comprising a receiving opening and a receiving space delimited by the stiffening body.Furthermore, the spreading element is designed to act on the stiffening body by spreading it open, such that the stiffening body is in a force-fit position against the respective circumferential surface of the adjacent battery cells and / or against the respective inner wall of the housing. Advantageously, two or more stiffening devices are provided, each of which is assigned to a separate space.Furthermore, according to the invention, the respective stiffening body and the respective spreading element are designed as separate components, wherein the spreading means is designed as an elongated spreading element and is dimensioned in such a way that it can be received in the recess of the respective stiffening body, and wherein the respective spreading element is designed in the form of a screw, rivet, mandrel, cylindrical pin or bolt, so that it can be easily assembled and / or disassembled.

[0017] The major advantage of the battery according to the invention lies in the fact that the stiffening devices inserted into the spaces between the battery cells forcefully clamp or wedge the battery cells against each other and / or against the inner wall of the battery housing. The stiffening devices arranged in the spaces hold the battery cells precisely in their position and ensure that the battery cells are held securely within the housing, preventing displacement. Due to the secure retention of the battery cells by means of the stiffening devices, the battery cells no longer need to be fixed in the housing by a permanent, bonded connection; that is, the battery cells do not need to be attached to the housing or the cooling plate with adhesive, nor do the spaces in the housing need to be filled with a potting compound.Accordingly, the material-bonded connection using adhesive and / or potting compound is replaced by a force-bonded connection.

[0018] The stiffening devices arranged in the spaces between the battery cells and the battery cells themselves form a kind of composite structure capable of absorbing forces acting on the battery. This composite structure is particularly effective at absorbing forces when a stiffening device is arranged in each space within the battery. Therefore, the battery according to the invention is particularly well-suited for batteries integrated into vehicles, such as 400-volt or 800-volt batteries. These batteries are generally also referred to as drive or traction batteries. However, the battery can also be used as an energy storage device for photovoltaic systems. In this case, the battery is specifically a rechargeable battery, also known as an accumulator or simply accumulator.

[0019] In the manufacturing process, not only can adhesives and / or potting compounds now be dispensed with, but a battery is also provided that can be easily assembled and disassembled, and thus recycled. This is because the stiffening elements are simply connected to the battery cells and / or the casing by friction, allowing the battery to be easily disassembled and separated into its individual components. A further advantage is that individual defective or damaged stiffening elements and / or defective or damaged battery cells can be removed and replaced from the battery without much effort. The stiffening elements can also be retrofitted into existing batteries.

[0020] Thus, the expanding element is designed as an elongated expanding element and is dimensioned such that it can be received in the recess of the respective stiffening body. The length of the expanding element corresponds at least to the length of the recess of the stiffening body. Preferably, the length of the expanding element is greater than the length of the recess of the stiffening body, so that the expanding element projects beyond the receiving opening of the stiffening body. It has proven particularly advantageous that the respective elongated expanding element is designed in the form of a screw, rivet, mandrel, cylindrical pin, or bolt. In a preferred embodiment, the expanding element is designed as an expanding mandrel or expanding rivet. This allows the expanding element to be manufactured simply and cost-effectively.

[0021] The operating principle of the stiffening device is similar to that of a standard dowel. The stiffening element is inserted or pushed into one of the spaces between the battery cells, in particular the space between two, three, or four adjacent battery cells, or into one of the spaces between the battery cells and the respective housing wall. The elongated expanding element, in particular the expanding mandrel or expanding rivet, is then pushed or screwed into the recess of the stiffening element. At the end of the joining process, the expanding element is at least partially received in the recess of the stiffening element, whereby the expanding element causes the wall or wall sections to expand.The wall plates are spread apart, and then the wall of the stiffening body is brought into contact with the circumferential surface of the battery cells and / or the housing wall, ensuring a large and secure fit. The battery cells are thus fixed in their position, preventing shifting and tilting; that is, the battery cells cannot tip over or be moved horizontally. Alternatively, the spreading element can first be inserted into the space, followed by the stiffening body. The functional principle remains unchanged by the reversed assembly sequence.

[0022] To dissipate as much heat as possible from the battery cells through the wall of the stiffening body, the stiffening body, when extended or spread, makes contact with the circumferential surfaces of the respective battery cells and / or the housing wall over as large an area as possible. Depending on the flexibility of the stiffening body, however, it may also only make contact with the circumferential surfaces of the respective battery cells and / or the housing wall at specific points. It is also conceivable that the stiffening body has a surface structure or profile on its outer surface, such as knob-like protrusions, grooves, ribs, or similar structures. In yet another alternative embodiment, perforations or lateral openings are incorporated into the wall of the stiffening body. The design of the stiffening body depends primarily on its intended use.

[0023] The radial expansion or spreading can be achieved in two different ways. The expanding element can be shaped and / or dimensioned such that it pushes the wall or wall sections of the stiffening body outwards. For this purpose, the expanding element has an interference fit with the recess in the stiffening body. To make it particularly easy to insert the expanding element into the recess, it can also be conical or tapered. Alternatively, the expanding element can be in the form of a screw. In this case, the expanding element has a shaft section and a head section extending longitudinally from the shaft section. In this embodiment, the expanding element has an external thread on its outer surface, while the inside of the stiffening body is provided with a corresponding internal thread.When assembling the stiffening device, the expanding element is screwed into the recess of the stiffening body, initially until the head of the expanding element rests against the wall of the stiffening body. As the expanding element is screwed in further, the stiffening body is compressed by the head of the expanding element. The further the expanding element is screwed into the stiffening body, the greater the pressure exerted on the stiffening body by the head of the expanding element, and thus the greater the compression of the stiffening body.

[0024] Alternatively, the stiffening body can be shaped or dimensioned such that the insertion of a substantially cylindrical expanding element achieves the widening or spreading of the stiffening body. For this purpose, the wall or wall sections are inclined inwards relative to the central or longitudinal axis, so that they are forced apart when the stiffening body and expanding element are joined.

[0025] In this case, the elongated stiffening body has a borehole- or blind-hole-like recess, forming a base section and a side wall. The recess extending longitudinally along the stiffening body is also referred to as an expansion bore. The side wall and the base section define an interior space, the so-called receiving space, which serves to accommodate an expansion element. The side wall can have simple or cross-slotted slots. Instead of simple or cross-slotted slots, it can also have, for example, star-shaped or other slotted slots.When designing the wall of the stiffening body, it is crucial that the wall can be spread open by the expanding element in such a way that the wall or wall sections press evenly against the respective circumferential surfaces of the adjacent battery cells and / or against the respective housing wall. Therefore, the lateral wall need not form a completely closed circumferential surface. Rather, the circumferential surface can have areas where the wall is absent or where recesses or openings are incorporated into the wall. In one embodiment, the stiffening body has a base section and two opposing wall sections or wall plates projecting from the base section, namely a first wall section and a second wall section. Four, six, eight, ten, or more wall sections can also be provided.

[0026] If a spreading element is used in the stiffening device, the lateral wall of the stiffening body does not need to be completely closed around its circumference. In contrast, when using a spreading medium, especially a pressurized spreading medium, the stiffening body must be closed except for the receiving / filling opening, so that the spreading medium cannot escape from the receiving chamber during pressure forming.

[0027] In a particularly preferred embodiment, the expanding agent can be a pressurized expanding medium that can be introduced into the receiving space of the respective stiffening body in such a way that it plastically deforms and radially expands the stiffening body. In this embodiment, a gaseous medium, in particular air or another gas, is used as the expanding medium. In this embodiment, the stiffening body is preferably designed as a thin-walled stiffening body and is preferably made of metal, plastic, or a composite material. The stiffening body can thus be designed as a tubular or hollow cylindrical stiffening body, which is closed at one end by means of a bottom section and has a filling opening at the other end. With the aid of a pressurization device, a pressurized gas can be introduced into the interior or...The receiving chamber of the stiffening element is inflated with compressed air. The introduction of pressurized gases creates a high internal pressure within the receiving chamber of the stiffening element, causing it to plastically deform and expand outwards, i.e., in a radial direction. The pressurization device can comprise a compressed air source, at least one filling element, and at least one control unit.

[0028] It is also conceivable that the thin-walled stiffening element is made of plastic and is first preheated and then plastically deformed and expanded by introducing a pressurized expanding medium. The pressure forming of the stiffening element is similar to the blow molding process used for plastic containers. Through this pressure forming, the stiffening element conforms to the surrounding surfaces of the battery cells and / or the respective housing wall, enabling a force-fit and form-fit connection.

[0029] Especially with metallic stiffening elements, it is necessary to provide electrical insulation between the stiffening element and the battery cells. Advantageously, the stiffening element is provided with an electrically insulating coating on its outer surface. Optionally or additionally, the battery cells can also be provided with an electrically insulating coating on their circumferential surfaces.

[0030] To prevent the expanding element and the stiffening body from unintentionally separating from each other in the assembled state, geometric modifications can be made to the inside of the stiffening body and / or to the outer surface of the expanding element. Preferably, first engagement means are formed on the outer surface of the respective expanding element, while second engagement means, which can engage with the first engagement means, are formed on the respective stiffening body. The first and second engagement means can be in the form of a thread, a surface structure, in particular notches, grooves, serrations, etc., or a sawtooth, stepped, grooved, or wave-like profile. The first and second engagement means thus ensure that the expanding element can only be moved out of the stiffening body by applying a predefined force.

[0031] A further advantage is that the respective stiffening element is designed as a separate component, allowing for easy assembly and disassembly. The respective expansion element can also be designed as a separate component. In an alternative embodiment, either the respective stiffening element or the respective expansion element is part of the housing or part of a base plate. In this case, the base plate can also be a conventional cooling plate. Accordingly, the stiffening element or the expansion element can be integrally connected to the base plate, particularly the cooling plate; that is, the respective expansion element or stiffening element and the base plate are formed in one piece or manufactured from a single casting. The one-piece design has the significant advantage of considerably simplifying the assembly or mounting of the battery cells within the battery housing.In addition to the expanding elements or stiffening bodies, the base plate can be provided with recesses into which the battery cells can be inserted. These recesses therefore have the contour of the battery cell base.

[0032] Another advantage is certainly the effective cooling of the battery, since the stiffening devices located in the spaces between can dissipate some of the heat directly.

[0033] Because the base plate and stiffening element are designed as a single unit, or the base plate and expansion element together, the surface area of ​​the cooling plate is significantly increased. In particular, the stiffening elements, with their walls or wall sections, make extensive contact with the circumferential surface of the battery cells, thus enabling effective heat dissipation. In other words, the stiffening element not only stiffens the battery but also dissipates heat, thereby improving the cooling performance of the cooling plate. The more stiffening elements a battery incorporates, the better the cooling performance achieved by the cooling plate and the stiffening elements.

[0034] Finally, the invention discloses a method for manufacturing such a battery, in particular a vehicle battery, in which a plurality of battery cells, which are arranged in a housing of the battery and electrically connected to one another, are arranged on a base plate in the housing before the battery cells are clamped or stiffened against each other by means of at least one stiffening device, in which at least one stiffening device is used which is arranged or inserted in one of the spaces between the battery cells or the battery cells and the housing.is inserted and then either expanded with a spreading element or stretched with a pressurized gaseous medium, in such a way that the stiffening body comes into contact with the circumferential surface of the respective adjacent battery cells and / or with the respective adjacent inner wall of the housing over a large area and in a force-fit manner.

[0035] Batteries can be configured in various ways. If they are batteries for vehicles, especially electric vehicles, they can be designed as battery packs or battery modules. A battery module also has a housing that contains multiple battery cells, which are electrically connected. The battery modules are connected in series to achieve high output voltages. Several battery modules can be combined to form a battery system. The number of battery modules in a battery system depends primarily on the application and design of the system. The greater the range desired by the customer, the more modules are used in the battery system.

[0036] In contrast, novel concepts for drive or traction batteries for vehicles forgo modular construction. Instead, the battery cells are connected to each other and integrated directly into the battery housing; that is, the battery cells are directly housed within the battery casing. This is also known as "cell-to-pack" technology. Alternatively, the battery cells can be integrated into the vehicle chassis; this is known as "cell-to-chassis" technology. Here, the batteries are integrated directly into the chassis, which not only eliminates the need for large battery packs but also the individual modules in which the individual battery cells were previously grouped. In "cell-to-chassis" technology, the housing is formed by the vehicle itself, specifically the vehicle frame and / or by the vehicle's components.The battery according to the invention is suitable for any type of drive or traction battery. However, the invention is not limited to drive and traction batteries. The key feature is that a multitude of battery cells are housed in a casing and electrically connected to one another.

[0037] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0038] The invention will be explained in more detail below with reference to an exemplary embodiment in conjunction with the schematic drawing. The drawing shows...

[0039] Fig. 1 shows a sectional view through a detailed view of the battery according to the invention with a spread and unspread stiffening body and a spreading element; Fig. 2 shows a sectional view through a detailed view of the battery according to the invention with a spread and unspread stiffening body and an alternative spreading element;

[0040] Fig. 3a shows a sectional view through a detailed view of the battery according to the invention with a spreading element integrally connected to the base plate;

[0041] Fig. 3b shows a sectional view through a detailed view of the battery according to the invention with a stiffening body integrally connected to the base plate;

[0042] Fig. 4 shows a sectional view through a detail view of a stiffening device comprising a stiffening body and a spreading element in the form of a screw;

[0043] Fig. 5a shows a sectional view through a detailed view of the battery according to the invention with a non-spread stiffening body;

[0044] Fig. 5b shows a sectional view through a detailed view of the battery according to the invention with a stiffening device, in which the spreading element and the stiffening body each have engagement means;

[0045] Fig. 6 shows a top view of a schematically represented battery with a plurality of battery cells and a plurality of stiffening devices;

[0046] Fig. 7a shows a sectional view through a detail view of a stiffening device which is pressurized with a spreading medium and

[0047] Fig. 7b shows a sectional view through a detail view of a stiffening device which is plastically deformed by a pressurized spreading medium.

[0048] Figure 6, reference numeral 1, shows a battery, in particular a storage battery or a motor vehicle battery. A battery is generally understood to be a larger assembly comprising a multitude of battery cells. Within the scope of this application, a battery is understood to be, in particular, a high-voltage storage device for the propulsion system of an electric or hybrid vehicle; however, other types of batteries, especially storage batteries, are also included.

[0049] Such batteries 1 comprise a housing and a plurality of battery cells 10, which are arranged in the housing of the battery 1 and electrically connected to one another. The batteries can differ in the number, size, and configuration of the battery cells. In practice, there is a wide variety of battery types and the battery cells they contain. For the purposes of the invention, a battery cell is understood to be an electrochemical storage cell, preferably a secondary cell. The term "cell" is preferably understood with regard to its physical appearance as the smallest contactable unit. In practice, there are many different types of battery cells, namely cylindrical cells, prismatic battery cells, especially flat cells, and so-called pouch cells.

[0050] The battery typically has a base plate 70 on which the battery cells 10 are arranged. Not shown in the figures, the base plate 70 may have recesses for receiving the battery cells, the recesses having the contour of the battery cell base. The base plate 70 is preferably designed as a cooling plate. The base plate 70 has a bottom surface and a top surface for receiving the battery cells 10, both of which extend in a principal plane E.

[0051] The battery cells 10 are rechargeable electrochemical storage cells of an elongated, cylindrical shape. However, the present invention is not limited to this. The battery cells 10 are arranged in a predetermined pole orientation, which is not described further here, according to a predetermined circuit diagram. The longitudinal axes of the battery cells 10 are parallel to each other and perpendicular to the top surface of the base plate 70.

[0052] Due to the shape and arrangement of the battery cells within the housing, gaps 20 are formed between the battery cells 10. Similarly, gaps 20 are formed between the housing wall of the battery 1 and the battery cells 10. In conventional batteries, these gaps are usually filled with a potting compound to stabilize the battery and create a battery cell assembly capable of absorbing forces. In contrast, stiffening devices 30 are now inserted into the gaps 20. The stiffening devices 30 are thus arranged in the gaps 30 and each consists of an elongated stiffening body 50 and a corresponding expanding element 40. The operating principle corresponds to that of a standard dowel. Accordingly, the stiffening body 50 is expanded, spread, or compressed radially by the expanding element 40, so that the wall or...

[0053] Wall sections of the stiffening body are pressed outwards and come into contact with the circumferential surfaces of the adjacent battery cells 10 and / or the respective housing wall. The expansion of the stiffening body 50 creates a force-fit connection between the stiffening body 50 and the adjacent battery cells 10. Thus, the battery cells 10 are clamped in place within the battery by the integrated stiffening elements 30, meaning the battery cells are held securely within the battery against displacement and tilting.

[0054] The stiffening device 30 can, for example, be arranged between two adjacent battery cells 10. However, it can also be placed in the space 20 between three adjacent battery cells 10 arranged approximately in a triangular shape. If at least four battery cells are present, arranged in a square, the stiffening device 30 can be placed in the space 20 between these four battery cells 10. The stiffening device 30 can also be located between the inner wall of the battery housing and a battery cell 10, or between the inner wall of the battery housing and two adjacent battery cells 10.

[0055] As shown in Figures 1, 2, and 5a, the elongated stiffening body 50 is designed as a separate component and can be configured in a variety of ways. Preferably, the stiffening body 50 has a longitudinally extending recess 51, shaped like a hole or blind hole, for receiving a spreading element 41. Accordingly, the stiffening body 50 has a lateral wall or lateral wall sections, so-called...

[0056] The stiffening body 50 has expanding plates which can be pressed radially outwards by the expanding element. On one side, the stiffening body has a base section from which the wall 52 or wall sections project upwards. On the side facing away from the base section, there is a receiving opening for inserting the expanding element 40. The recess 51 forms a cavity, the so-called receiving chamber 56, in the stiffening body, in which the expanding element 40 can be received. Preferably, the expanding element 41 is pushed into the receiving chamber 56 until it rests on the base section.

[0057] In an advantageous embodiment, the stiffening body 50 is part of the base plate 70, in particular a cooling plate, as shown in Figure 3b. Here, the base plate 70 forms the base section of the stiffening body 50. The advantage is that, in the expanded state, the stiffening body 50 bears a large area against the outer surface of the battery cells and can absorb the heat from the battery cells, i.e., the cooling surface of the base plate 70 is significantly increased. The reverse arrangement is also conceivable, in which the expanding element 41 is part of the base plate or the expanding element and the base plate 70 are formed as a single piece, as shown by way of example in Figure 3a. The advantage is that the assembly of the battery is more efficient and therefore more cost-effective due to the one-piece design variant of the base plate 70 and expanding elements 41 or stiffening body 50.

[0058] Regardless of whether the stiffening body 50 and the expanding element 41 are separate components or whether the stiffening body 50 or the expanding element 41 is integrally connected to the base plate 70, the stiffening body 50 is stretched, expanded or compressed by the expanding element in a radial direction, i.e. parallel to the main plane E or perpendicular to the longitudinal axis LA of the stiffening body 50.

[0059] According to Figures 1 to 5b, the spreading means 40 are designed as an elongated spreading element 41. The spreading element 41 preferably has a shaft section and a head section adjoining the shaft section. The spreading element 41 is designed and dimensioned such that it can be inserted into the recess 51 of the stiffening body 50, so that the stiffening body expands radially at the end of the joining process and the wall sections or wall plates, so-called spreading plates, come into contact with the outer surfaces of the battery cells 10 over a large area. Advantageously, the wall section comes into contact with the outer surface of the adjacent battery cell 10 over its entire longitudinal extent.

[0060] The expanding element 41 can be designed in the form of a screw, rivet, pin, dowel, or bolt. It is also conceivable that commercially available screws, rivets, bolts, or dowel pins could perform the function of the expanding element 41. Figure 1 shows an example of an expanding element 41 in the form of a rivet, the shank section of which is completely received in the recess 51 of the stiffening body 51 and clamps the stiffening body 50 against the adjacent battery cells 10. Figure 1 also shows the radially acting forces F2, which are generated by joining the stiffening body and the expanding element. Depending on the design of the stiffening body and the expanding element, the resulting radial forces F2 can be precisely defined. Figure 4, on the other hand, shows a variant embodiment of the expanding element 41 in which the expanding element 41 is designed in the form of a screw.In this case, the expanding element 41 has an external thread on its outer surface 42 and the stiffening body has a corresponding internal thread on its inner surface 58, which interacts with the external thread of the expanding element 41.

[0061] To prevent the assembled stiffening device 30 from unintentionally coming loose, engagement means 44, 62 can be provided both on the inner surface 58 of the stiffening body 50 and on the outer surface 42 of the expanding element 41. The outer surface 42 has first engagement means 44, and the inner surface 58 has second engagement means 62. In Figures 1, 3a, 3b, and 5b, a sawtooth-like profile is formed on the inner surface 58 and on the outer surface 58. However, the design is not limited to this type of engagement means. Rather, the engagement means 44, 62 can be designed differently. For example, serrations, notches, shoulders, or diameter variations are conceivable. The essential point is that the engagement means 44, 62 prevent the expanding element 41 from unintentionally coming loose from the stiffening body 50.

[0062] As shown in Figure 4, the expanding element 41 is a screw that is screwed into the stiffening body 50. By screwing the expanding element 41 into the stiffening body 50, the head section of the expanding element 41 comes into contact with the wall of the stiffening body. In the right-hand illustration in Figure 4, the expanding element 41 is screwed further into the stiffening body 50, so that the wall 52 of the stiffening body is compressed and thus expanded. The further the expanding element 41 is screwed in, the greater the radially acting forces Fl. The head section of the expanding element 41 exerts compressive forces F2 on the stiffening body 50 in the longitudinal direction LA.Figure 7 shows an alternative embodiment of the stiffening device 30, comprising a substantially tubular or hollow cylindrical stiffening body 50, which is open at one side and has a filling opening 54 on this side. The stiffening body 50 is preferably thin-walled and made of either metal or plastic. In this embodiment, the expanding agent 40 is an expanding medium, in particular a gaseous expanding medium 46. Preferably, air or an inert gas is used as the expanding medium 46. The expanding medium 46 is introduced into the receiving chamber 56 of the stiffening body 50 under high pressure, so that the wall 52 of the stiffening body 50 is plastically deformed and expanded by the internal pressure F2. Through pressure forming, the wall 52 of the stiffening body 50 conforms to the outer surface of the adjacent battery cells 10 and enables a force-fit / form-fit connection.The stiffening elements 50 can also be expanded very precisely here, since the expanding medium is extremely easy to regulate. A device 100 for pressurizing the expanding medium 46 is provided for introducing it into the stiffening element 50.

[0063] Furthermore, a method for manufacturing a battery, particularly for motor vehicles such as electric cars, is disclosed, in which a plurality of battery cells 10, which are arranged in a housing of the battery 1 and electrically connected to one another, are arranged on a base plate 70 in the housing before the battery cells 10 are crimped or stiffened against one another by means of at least one stiffening device 39. For this purpose, at least one stiffening device is used, which is arranged or inserted into one of the spaces 20 between the battery cells or between the battery cells and the inner wall of the housing.is inserted, and is then either expanded with a spreading element 40 or plastically deformed and stretched with a pressurized gaseous spreading medium 46, in such a way that the stiffening body 50 comes into contact with the circumferential surface of the respective adjacent battery cells 10 and / or with the respective adjacent inner wall of the housing over a large area and in a force-fit manner.

[0064] If the respective stiffening device 30 consists of a stiffening body 50 and an expanding element 41, either the expanding element 41 or the stiffening body 50 is first inserted into the designated space 30. If the stiffening body 50 is inserted into the space 30, the expanding element 41 is subsequently inserted into the recess of the stiffening body 30, or vice versa. At the end of the joining process, the expanding element expands the stiffening body 50 such that its wall comes into contact with the circumferential surface of the adjacent battery cells in a force-fit manner.

[0065] If, on the other hand, the respective stiffening device 30 is pressurized with a gaseous spreading medium 46, the stiffening body 50 is first inserted into a specific intermediate space 30. Subsequently, the stiffening body 50 is pressurized with compressed air. For this purpose, a device for pressurizing with compressed air is provided, which has at least one filling valve or connection piece in order to introduce the compressed air into the receiving chamber 56 of the stiffening body 50 via the filling opening 54.

[0066] Reference symbol list

[0067] 1 battery

[0068] 10 battery cells

[0069] 20 spaces

[0070] 30 Stiffening device

[0071] 40 spreading agents

[0072] 41 Spreading element

[0073] 42 Surface area

[0074] 44 first intervention method

[0075] 46 gaseous spreading medium

[0076] 50 stiffening bodies

[0077] 51 Exclusion

[0078] 52 wall

[0079] 54 Intake opening / Filling opening

[0080] 56 Recording room

[0081] 58 Inside

[0082] 60 Outside

[0083] 62 second intervention method

[0084] 70 Base plate / floor plate / cooling plate

[0085] 100 Device for pressurizing

[0086] LA Longitudinal axis / Longitudinal direction

[0087] E Main level

[0088] Fl radial forces

[0089] F2 pressure forces

Claims

Mercedes-Benz Group AG Patent claims 1. Battery (1) for vehicles, comprising a plurality of battery cells (10) arranged in a housing and electrically connected to one another, wherein gaps (20) are formed between adjacent battery cells (10) and between the battery cells (10) and the housing, and comprising at least one stiffening device (30) for stiffening the battery (1), wherein the at least one stiffening device (30) is arranged in one of the gaps (20) of the battery (1) and comprises an elongated stiffening body (50) that can be expanded in the radial direction and a spreading means (40), wherein the stiffening body (50) has a recess (51) extending in the longitudinal direction (LA) of the stiffening body (50), preferably bore- or blind-hole-like, comprising a receiving opening (54) and a receiving space (56) bounded by the stiffening body (50), and wherein the spreading means (40) is configured as follows: is,that it acts on the stiffening body (50) and spreads it open, such that the stiffening body (50) bears against the respective circumferential surface of the adjacent battery cells (10) and / or against the respective side wall of the housing, characterized in that the respective stiffening body (50) and the respective spreading element (41) are designed as separate components, wherein the spreading means (40) is designed as an elongated spreading element (41) and is dimensioned such that it can be received in the recess (51) of the respective stiffening body (50), and wherein the respective spreading element (41) is designed in the form of a screw, rivet, pin, dowel or bolt, so that it can be easily assembled and / or disassembled.

2. Battery (1) according to claim 1, characterized in that two or more stiffening devices (30) are provided, each of the stiffening devices (30) being assigned to a separate space (20).

3. Battery (1) according to claim 1 or 2, characterized in that the respective spreading element (41) has a lateral surface (42) and first engagement means (44) are formed on the lateral surface (42), and the respective stiffening body (50) has a lateral wall (52) with an outer surface (60) and an inner surface (58) limiting the receiving space (56) and second engagement means (62) that can be brought into engagement with the first engagement means (44) are formed on the inner surface (58).

4. Battery (1) according to claim 3, characterized in that the first and second engagement means (44, 62) are formed in the form of a thread, a surface structure, in particular notches, recesses, teeth, or a sawtooth, step-like, groove-shaped, wave-shaped profile.

5. Battery (1) according to one of the preceding claims, characterized in that the battery (1) comprises at least one base plate (70) and the respective stiffening body (50) or the respective spreading element (41) is formed as part of the base plate (70).

6. Battery (1) according to one of the preceding claims, characterized in that the respective stiffening body (50) is thin-walled and consists of a metal, plastic or a composite material.

7. Battery (1) according to one of the preceding claims, characterized in that the respective stiffening body (50) is provided on the outside (60) with an electrically insulating coating.

8. Method for manufacturing a battery (1) for vehicles, in which a plurality of battery cells (10), which are arranged in a housing and electrically connected to one another, are arranged on a base plate (70) in the housing before the battery cells (10) are crimped and / or stiffened against one another by means of at least one stiffening device (30), in which at least one stiffening device (30) is used which is arranged in one of the spaces between the battery cells (10) or the battery cells (10) and the housing, or is inserted and / or plugged in, and is then spread open with a spreading element (41), such that the stiffening body (50) comes into frictional contact with the circumferential surface of the respective adjacent battery cells (10) and / or with the respective adjacent side wall of the housing, characterized in thatthat the respective stiffening body (50) and the respective expanding element (41) are designed as separate components, wherein the expanding element (40) is designed as an elongated expanding element (41) and is dimensioned such that it is received in the recess (51) of the respective stiffening body (50), and wherein the respective expanding element (41) is designed as a screw, rivet, mandrel, cylindrical pin or bolt, so that it can be easily assembled and / or disassembled.

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