Temperature-control device for a battery system having a main body and a plurality of bearing sleeves arranged in a flow channel

Abstract

The invention relates to a temperature-control device for a battery system having a main body (1) and a plurality of bearing sleeves (2) for battery cells (3), which bearing sleeves are arranged in a flow channel (4), wherein a wall portion (8) of the main body (1) is interrupted by a receiving opening (7) which opens into a bearing sleeve (2). In order to produce a temperature-control of the type presented at the outset with an integrated cooling fluid flow channel in such a way that it is as light, simple and cheap to manufacture as possible and in which the electrical power of the battery cells (3) can be tapped simply, according to the invention the bearing sleeve (2) is formed from the wall portion (8) of the main body (1).

Description

[0001] Temperature control device for a battery system with a base body and several bearing sleeves arranged in a flow channel

[0002] Technical area

[0003] The invention relates to a temperature control device for a battery system having a base body and a plurality of bearing sleeves for battery cells arranged in a flow channel, wherein a wall section of the base body is pierced by a receiving opening which opens into a bearing sleeve.

[0004] State of the art

[0005] Temperature control devices are known from the prior art that have a base body forming bearing sleeves. DE102011017375A1 shows a temperature control device with such a base body, which is designed without a base and cover plate and has a plurality of bearing sleeves connected to the base body via webs. These webs simultaneously define a plurality of flow channels that run parallel to the longitudinal axes of the battery cells. In order to form a fluid-tight flow channel and to mechanically fix the battery cells, a separate base and cover plate is provided that secures the battery cells in the bearing sleeves, at least one of which has openings aligned with the bearing sleeves for electrical contact.

[0006] A disadvantage of the current state of the art, however, is that the bearing sleeves are complex to manufacture due to their one-piece construction with the base body. To facilitate production and ensure good heat transfer to the battery cells, it is known from the current state of the art to manufacture the base body from metal. Aside from the resulting relatively high weight of the temperature control device, which makes its use in electromobility unattractive, electrical insulation of the battery cells is significantly more difficult, particularly because cooling fluids with good thermal conductivity properties are also electrically conductive and therefore cannot be used in combination with electrically conductive base bodies.Although it is also known from DE102011017375A1 to provide the bearing sleeves with an insulating layer on their inside, this further complicates production and in turn reduces the thermal conductivity.

[0007] US 2013 / 004820 A1 discloses a temperature control device for a battery system. This temperature control device comprises a base body and several storage sleeves for battery cells arranged in a flow channel. Both cover sides of the base body are perforated by receiving openings that lead into the storage sleeves.

[0008] Description of the invention

[0009] The invention is therefore based on the object of producing a temperature control device with an integrated cooling fluid flow channel that is as light, simple and inexpensive to manufacture as possible.

[0010] The invention achieves this objective in that the bearing sleeve is formed from the wall section of the base body. As a result of these measures, the base body, which for example consists of a one-piece or materially bonded hollow body, can form a fluid-tight flow channel together with the bearing sleeves without any additional components, without the need for a separate seal between the battery cells and the base body or the bearing sleeves. The temperature control device according to the invention thus facilitates the use of liquid cooling fluids, which usually have better thermal conductivity properties than gaseous ones. The bearing sleeves also form burst protection to prevent the battery cells from rupturing on the shell side in the event of a thermal runaway. The openings according to the invention can be easily implemented in a wall section of the base body from a manufacturing perspective and also facilitate production and / orthe positioning of the bearing sleeves, since according to the invention the openings form a passage to the bearing sleeves. In principle, it is irrelevant whether the bearing sleeves are formed integrally with the base body or are inserted into the base body as separate components and, for example, are positively connected to it. The arrangement of the receiving openings and bearing sleeves according to the invention also allows greater design freedom in the arrangement of the flow channel. In a preferred embodiment, the main flow direction of the flow channel can run transversely to the longitudinal axis of the bearing sleeves, so that the flow flows around them and the heat transfer from the battery cell via the bearing sleeve to the cooling fluid is improved. Simple production is further facilitated if the wall section of the base body, and preferably the entire base body, is made of thermoplastic material.In a preferred embodiment, a flow divider is provided in the flow channel, which divides the flow channel into several sections, wherein the cooling fluid passes through these sections one after the other and in each section only flows around an outer wall section of the bearing sleeves in the flow channel. Since the cooling fluid flows around the bearing sleeves one after the other, but in each section only a section of the outer wall and not the entire outer wall, the temperature spread between the battery cells can be reduced. In a preferred embodiment, the bearing sleeves are made of mono- or copolymeric thermoplastic material, for example polyolefin, polyvinylidene fluoride, polytetrafluoroethylene, polycondensates, acrylonitrile butadiene styrenes or fluoroelastomers, and are stretched, preferably under the influence of heat, such that their free inner diameter expands.To improve thermal conductivity and / or reduce electrical conductivity while simultaneously increasing dielectric strength, the material may contain fillers, for example carbon black and / or inorganic fillers, particularly mineral fillers. The stretching process can be terminated by subsequent cooling, so that the expanded free inner diameter of the bearing sleeves is maintained under internal structural stress. After the battery cells have been inserted, the bearing sleeves are heated so that the structural stresses are released and the inner diameter is reduced again, allowing the bearing sleeves to fit tightly around the battery cells. In one embodiment, the wall section forms a wall of the base body, wherein this wall is perforated by a plurality of receiving openings.This results in a temperature control device for a battery system with a base body and a plurality of bearing sleeves for battery cells arranged in a flow channel, wherein a wall of the base body is perforated by receiving openings which open into the bearing sleeves, wherein the bearing sleeves are preferably formed from the wall of the base body.

[0011] To enable the use of electrically conductive fluids, it is proposed that the bearing sleeves be electrical insulators. While the bearing sleeves form a physical barrier between the battery cell and the cooling fluid, which in principle impairs heat transfer, it has been found that this apparent disadvantage enables the use of electrically conductive cooling fluids without increasing the risk of a short circuit in the temperature control device. Electrically conductive cooling fluids typically exhibit a thermal conductivity that is so superior to that of electrically insulating cooling fluids that the hindered heat transfer is more than compensated for, and overall, more heat energy can be transferred from the battery cell to the cooling fluid via the bearing sleeve than would be possible without the bearing sleeve to an electrically insulating cooling fluid.This effect is further enhanced when using peeled battery cells, i.e. battery cells whose casing has been at least partially removed to create electrical contact, since the casing also makes it more difficult for thermal energy to dissipate from the interior of the battery cell, thus enabling not only easier electrical contact but also improved heat transfer.

[0012] Both the insertion of the battery cells and their storage and the heat transfer to the cooling fluid in the flow channel can be improved if battery cells are inserted into the bearing sleeves with a press fit. As a result of this measure, the battery cells can be pressed into the bearing sleeves. Also, no additional component such as a cover or a locking device is required to secure the battery cells in the bearing sleeves, since the press fit, with a suitable selection of the diameter of the bearing sleeve, secures the battery cell with friction and / or form-fitting. Due to the press fit, the battery cell lies at least partially tightly against the bearing sleeve on the shell side, thus facilitating heat transfer via the bearing sleeve into the cooling fluid. To create the press fit, the diameter of the bearing sleeve can be smaller than that of the battery cell, at least in sections, before the battery cell is inserted.Preferably, the diameter of the bearing sleeves decreases starting from the receiving openings so that the press fit can be created simply by pressing in the battery cell when fitting the battery cell, and the bearing sleeve fits tightly around the circumference when the battery cell is inserted. In a preferred embodiment, at least one venting channel is provided on the shell side for each bearing sleeve, through which the air escaping from the bearing sleeve during the press fit can be discharged. This venting channel can be arranged on the bearing sleeve in such a way that it causes turbulence in the cooling fluid as it flows around the bearing sleeve, thus further improving the heat transfer from the battery cell via the bearing sleeve to the cooling fluid.

[0013] In order to facilitate the electrical contacting of the battery cells and to secure them mechanically better, it is proposed that the bearing sleeves have a sleeve base opposite the receiving openings. The sleeve base forms a stop for the battery cell along its longitudinal axis, so that the battery cell is positively secured in this direction. This makes it easy to define a uniform maximum storage depth for the battery cells in their respective bearing sleeves. As a result, each battery cell protrudes the same distance from its assigned receiving opening, which facilitates electrical contact, for example by means of a contact plate. In a special embodiment, each bearing sleeve has a hole in its sleeve base, through which, for example, a terminal of the battery cell can be contacted, or which serves as an outgassing valve.

[0014] To simplify mechanical and electrical access to the battery cells inserted into the bearing sleeves without compromising the flow channel, particularly in terms of its fluid tightness, the sleeve base can form an outer wall section of the base body. As a result of these measures, the sleeve base is not located within the flow channel, so that manipulation of the sleeve base is not accompanied by a leak in the flow channel and / or an electrical connection between the cooling fluid and the battery cell. This allows easy manipulation of the sleeve base from outside without compromising the functionality of the temperature control device. If, for example, a hole is provided in the sleeve base for electrical contact, this contact can be easily established via an external component, such as a contact plate, without the latter having to be inserted into the flow channel.

[0015] In order to minimize damage to the temperature control device caused by battery cell malfunctions, such as thermal runaway, it is proposed that the sleeve base include an outgassing valve. As a result of these measures, the kinetic energy released via released gas in the event of a malfunction is not transferred to the casing side of the bearing sleeve, but can be dissipated via the outgassing valve on the sleeve base. Depending on how the temperature control device is manufactured, the released gas is directed into the flow channel and can be removed with the cooling medium. Preferably, the sleeve base forms an outer wall section of the base body so that escaping gas from the temperature control device is removed without entering the flow channel and contaminating the cooling fluid. In the simplest case, the outgassing valve is a predetermined breaking point on the sleeve base.In a preferred embodiment, the outgassing valve is a mechanical valve, so that the temperature control device is not damaged even if a battery cell outgasses. In a particularly simple embodiment, the outgassing valve is a bursting membrane. The number of components of the temperature control device, and thus the number of seals required, can be minimized if the bearing sleeve is molded from the wall section of the base body. Molded in the context of the invention means that the bearing sleeve is formed from the wall section in a single molding step. As a result of these measures, at least the wall section of the base body and the bearing sleeves can be designed as a single piece, whereby these components neither need to be connected to one another nor do fluid-tight seals need to be provided.A further advantage is that the molding process reduces the wall thickness in the area of ​​the bearing sleeve, allowing for better heat transfer from the battery cell via the bearing sleeve to the cooling fluid. In the simplest case, the entire temperature control device can be formed in one piece from a hollow body by pressing the bearing sleeves, which allows the flow channel to form automatically inside the base body without any further manufacturing steps. Preferably, the bearing sleeves are formed in such a way that a sleeve base is also formed during the manufacturing step. One molding step can be forming.

[0016] The bearing sleeves can be formed, for example, by deep drawing. Multiple bearing sleeves can be formed from the wall section, so that at least two bearing sleeves are formed integrally with each other. In this way, the bearing sleeves can be easily inserted together into the flow channel. An easily assembled temperature control device is created when the wall section, together with the bearing sleeves, forms a removable wall of the base body.

[0017] To ensure that conventional manufacturing and molding methods can be easily used to produce the temperature control device, it is proposed that the base body be composed of two partial bodies that can be connected to one another in a fluid-tight manner. This allows the geometry of the two partial bodies to be designed in such a way that they can be easily manufactured. It also makes it easy to carry out manufacturing steps on parts of the base body that are difficult to access in the assembled state, such as the flow channel, before the latter is assembled in a fluid-tight manner. Thanks to these measures, a flow divider, for example, can be easily inserted before assembly. For example, the two partial bodies can be manufactured from two plates that are molded and then connected to one another. The fluid-tight connection can be created using a material bond and / or seals.Particularly simple manufacturing conditions arise when the parts are made of thermoplastic material and are joined together by welding.

[0018] Preferably, one partial body forms the wall section pierced by the receiving openings, which, together with the second partial body, defines the flow channel. In the simplest case, the wall section can consist of just a plate that is easily machined using conventional manufacturing methods such as spinning or deep drawing. This allows the receiving openings and preferably also the bearing sleeves to be manufactured on the first partial body without great effort. The second partial body is designed to complement the first partial body in such a way that, after assembly, both define the flow channel. For this purpose, the second partial body can be essentially trough-shaped, which also facilitates manufacturing using spinning, deep drawing, or similar processes.

[0019] Another easy-to-manufacture and mechanically particularly stable two-part design results when the end sections of the bearing sleeves opposite the receiving openings are connected to the second partial body in a fluid-tight manner. As a result of this measure, the bearing sleeves do not necessarily have to have sleeve bases, which simplifies production. The fluid-tight connection of the end sections of the bearing sleeves to the second partial body not only creates a fluid-tight flow channel, but also connects both partial bodies to one another at each bearing sleeve, thereby stiffening the entire temperature control device. If one partial body forms the bearing sleeves, their end sections can be welded to the second bearing body, for example. If this is not the case, the bearing sleeves can be welded to both partial bodies.Preferably, the second partial body forms a base for the bearing sleeves, which performs the same function as a sleeve base.

[0020] To ensure adequate protection of the battery cells in the event of a thermal runaway despite cost-effective manufacturing of the device, it is proposed that a bearing sleeve be provided for each battery cell. This spatially shields the battery cells from one another, with the bearing sleeves forming a protective barrier between the adjacent battery cells. In particular, if the bearing sleeves completely enclose the battery cells, an effective protective barrier for shielding defective battery cells can be achieved. Preferably, the battery cells are sealed fluid-tight from one another by the bearing sleeves to prevent any escaping hot gas from spreading toward the adjacent battery cells.

[0021] Preferred conditions for simple manufacturing can be achieved by designing the bearing sleeves as hollow cylinders, particularly with a circular base. This reduces corners and edges, which can lead to insufficiently precise results, particularly in forming processes such as deep drawing.

[0022] Brief description of the invention

[0023] The drawing shows an example of the subject matter of the invention.

[0024] Fig. 1 is an isometric view of a temperature control device according to the invention with inserted battery cells,

[0025] Fig. 2 is an exploded view of the tempering device according to the invention of Fig. 1 and

[0026] Fig. 3 shows a section along the line III - III of Fig. 1 on a larger scale.

[0027] Ways of carrying out the invention A temperature control device according to the invention comprises a base body 1 and a plurality of bearing sleeves 2 for battery cells 3. The base body 1 forms a fluid-tight flow channel 4 which has an inlet 5 and an outlet 6 and is filled with a cooling fluid during operation, which flows around the bearing sleeves 2. Efficient cooling fluids, i.e. those which can ensure good heat transfer between the battery cell 3 and the cooling fluid, are usually electrically conductive. However, if the bearing sleeves 2 are electrical insulators, such cooling fluids can still be used. This advantage of the improved heat transfer outweighs the disadvantage of the bearing sleeve 2 as an additional intermediate layer between the battery cell 3 and the cooling fluid.If the battery cells 3 are inserted into the bearing sleeves 2 with a press fit, so that, as shown in the figures, the bearing sleeves 2 are in contact over the entire circumference of the battery cell shells, the disadvantage described above is further reduced due to the large interaction surface available for heat transfer. To remove the air present in the bearing sleeve 2 during the press fit, ventilation channels (not shown) can be provided on the shell side of the bearing sleeves 2, which preferably also induce turbulence in the cooling fluid in the flow channel 4 to improve heat transfer.If the bearing sleeves 2 are formed from the wall section 8 of the base body 1, for example by deep drawing, as shown, this offers the further advantage, in addition to simplified production, that the material and production-related thinning of the walls of the bearing sleeves 2 occurs in comparison to the thickness of the wall section 8, whereby the thermal insulation properties of the bearing sleeves 2 are reduced as desired, but the necessary electrical insulation remains unaffected.

[0028] In order to store the battery cells 3 in the storage sleeves 2, they are pressed into the storage sleeves 2 via receiving openings 7. According to the invention, these receiving openings 7 are openings in a wall section 8 of the base body 1 and preferably have a sleeve base 9 opposite the receiving openings 7, which serves as a stop for the battery cells 3. The sleeve base 9 can also form an outer wall section of the base body 1, so that the inserted battery cell 3 remains accessible via the sleeve base 9. In this way, in the event of a malfunction, gases escaping from the battery cell 3 can be guided out of the temperature control device via an outgassing valve 10 and, in particular, these gases can be prevented from contaminating the cooling fluid in the flow channel 4.

[0029] The base body 1 of the illustrated embodiment is composed of two partial bodies 11, 12 to facilitate production. These two partial bodies 11, 12 are connected to each other in a fluid-tight manner, for example, by welding. One partial body 11 forms the wall section 8, which is perforated by the receiving openings 7 and, together with the second partial body 12, defines the flow channel 4. Regardless of whether sleeve bases 9 are provided for the bearing sleeves 2 or not, the end sections 13 of the bearing sleeves 2 can be connected to the second partial body 12 in a fluid-tight manner, which stiffens the temperature control device.

[0030] A further advantage of using two partial bodies 11, 12 is that a flow divider 14 can be used without great manufacturing effort. The flow divider 14 allows the inlet 5 and outlet 6 to be arranged on the same end face of the base body 1, while still ensuring uniform flow around all battery cells 3. The greater advantage, however, is that the flow divider 14 divides the flow channel 4 into two parallel sections, which the cooling fluid passes through one after the other. In each section, the cooling fluid only flows around either the upper or the lower half of the battery cells 3, but passes through each battery cell 3 twice, whereby the temperature gradient between the battery cells 3 and the cooling fluid at the outlet 6 can be reduced, and thus the temperature spread of the battery cells 3 within the temperature control device can be reduced.

[0031] In particular, it can be seen from Fig. 2 that each battery cell 3 can have its own bearing sleeve 2, wherein the bearing sleeves 2 completely enclose the battery cells 3. In this way, the battery cells 3 can be sealed fluid-tight from one another by the bearing sleeves 2. In a preferred embodiment, the bearing sleeves 2 are formed integrally with one another. The wall section 8 from which the bearing sleeves 2 are formed can, for this purpose, form a wall for the base body 1 that connects the bearing sleeves 2 to one another. Preferred manufacturing conditions, particularly with regard to forming processes, arise when the bearing sleeves 2 are formed as hollow cylinders, in particular with a circular base area.

Claims

Patent claims 1. Temperature control device for a battery system with a base body (1) and a plurality of bearing sleeves (2) for battery cells (3) arranged in a flow channel (4), wherein a wall section (8) of the base body (1) is pierced by a receiving opening (7) which opens into a bearing sleeve (2), characterized in that the bearing sleeve (2) is formed from the wall section (8) of the base body (1).

2. Tempering device according to claim 1, characterized in that the bearing sleeves (2) are electrical insulators.

3. Temperature control device according to one of claims 1 or 2, characterized in that battery cells (3) are inserted into the bearing sleeves (2) to form a press fit.

4. Tempering device according to one of claims 1 to 3, characterized in that the bearing sleeves (2) have a sleeve base (9) opposite the receiving openings (7).

5. Tempering device according to claim 4, characterized in that the sleeve base (9) forms an outer wall section of the base body (1).

6. Tempering device according to claim 4 or 5, characterized in that the sleeve base (9) has a degassing valve (10).

7. Tempering device according to one of claims 1 to 6, characterized in that the base body (1) is composed of two partial bodies (11, 12) which can be connected to one another in a fluid-tight manner.

8. Tempering device according to claim 7, characterized in that a partial body (11) forms the wall section (8) pierced by the receiving openings (7), which, together with the second partial body (12), delimits the flow channel (4).

9. Temperature control device according to one of claims 7 or 8, characterized in that the end sections (13) of the bearing sleeves (2) opposite the receiving openings (7) are connected to the second part body (12) in a fluid-tight manner.

10. Temperature control device according to one of claims 1 to 9, characterized in that a bearing sleeve (2) is provided for each battery cell (3).

11. Temperature control device according to one of claims 1 to 10, characterized in that the bearing sleeves (2) completely enclose the battery cells (3).

12. Temperature control device according to one of claims 1 to 11, characterized in that the battery cells (3) are sealed fluid-tight against one another by the bearing sleeves (2).

13. Tempering device according to one of claims 1 to 12, characterized in that at least two bearing sleeves (2) are formed integrally with one another.

14. Tempering device according to one of claims 1 to 13, characterized in that the bearing sleeves (2) are hollow-cylindrical.

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