Temperature control device for a battery system having a substrate and multiple housing sleeves arranged in a flow path.

Abstract

The present invention relates to a temperature control device for a battery system having a base body (1) and a plurality of housing sleeves (2) for battery cells (3) arranged in a flow path (4), wherein receiving openings (7) leading to the housing sleeves (2) are drilled in the wall portion (8) of the base body (1). In order to manufacture the above type of temperature control device with an integrated cooling fluid flow path as lightweight, simple and inexpensive as possible, and to allow easy extraction of power from the battery cells (3), it is proposed that the housing sleeves (2) are formed from the wall portion (8) of the base body (1).

Description

Technical Field

[0001] The present invention relates to a temperature control device for a battery system having a base body and a plurality of receiving sleeves for battery cells arranged in a flow path, wherein a receiving opening leading to the receiving sleeve is formed in a wall portion of the base body.

Background Art

[0002] From the prior art, temperature control devices with a base body forming a receiving sleeve are known. German Patent Application Publication No. 102011017375 shows a temperature control device having such a base body, which is formed without a base plate and a cover plate and has a plurality of receiving sleeves connected to the base body via webs. These webs also define a plurality of flow paths extending parallel to the longitudinal axis of the battery cell. To form fluid-tight flow paths and mechanically fix the battery cells, a separate base plate and a cover plate for fixing the battery cells in the receiving sleeves are provided, and at least one of these plates has an opening aligned with the receiving sleeve for electrical contact.

[0003] However, a disadvantage of the state of the art is that the manufacturing of the receiving sleeves is complicated due to the integral manufacturing with the base body. To facilitate manufacturing and establish good heat transfer to the battery cells, it is known from the prior art to manufacture the base body from metal. However, apart from the relatively high weight of the resulting temperature control device - which makes its use in the field of electric vehicles unattractive - the electrical insulation of the battery cells is extremely difficult because, in particular, a cooling fluid having good heat conduction characteristics is also conductive and thus cannot be used in combination with a conductive base body. Certainly, it is also known from German Patent Application Publication No. 102011017375 to provide an insulating layer inside the receiving sleeve, but this further complicates the manufacturing and also reduces the thermal conductivity.

[0004] A temperature control device for a battery system is described in U.S. Patent Application Publication No. 2013 / 004820. This temperature control device comprises a substrate and a plurality of housing sleeves for battery cells arranged in a flow path. Receiving openings leading to the housing sleeves are provided on both cover surfaces of the substrate. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102011017375 [Patent Document 2] U.S. Patent Application Publication No. 2013 / 004820 [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the fundamental problem underlying the present invention is to establish a temperature control device that integrates a cooling fluid channel, which is as lightweight as possible and can be manufactured simply and inexpensively. [Means for solving the problem]

[0007] The present invention solves the problems raised by forming the housing sleeve from the wall portion of the substrate. As a result of these measures, the substrate, which is, for example, a hollow body manufactured integrally or materially bonded, can, together with the housing sleeve, form a fluid-tight flow path without other parts, and there is no need to provide a separate sealing means between the battery cell and the substrate or housing sleeve. This makes it easier for the temperature control device according to the present invention to use a liquid cooling fluid, which usually has better thermal conductivity than a gaseous cooling fluid. Furthermore, the housing sleeve constitutes a rupture protection device to prevent the shell side of the battery cell from rupturing in the event of thermal runaway. The opening according to the present invention can be easily realized in the wall portion of the substrate from a manufacturing perspective, and also facilitates the manufacturing or positioning of the housing sleeve, because the opening constitutes a passage to the housing sleeve according to the present invention. Basically, it does not matter whether the housing sleeve is formed integrally with the substrate or inserted into the substrate as a separate part and coupled to the substrate, for example, by a symmetrical fitting. The arrangement of the receiving opening and housing sleeve according to the present invention also allows for greater structural freedom in the arrangement of the flow path. Therefore, in a preferred embodiment, the main flow direction of the flow path may extend laterally with respect to the longitudinal axis of the housing sleeve, so that the fluid flows around the housing sleeve, improving heat transfer from the battery cells to the cooling fluid through the housing sleeve. If the wall portion of the substrate, preferably the entire substrate, is manufactured from a thermoplastic material, the easy manufacturing process becomes even easier. In a preferred embodiment, a flow divider is provided in the flow path that divides the flow path into multiple sections, and the cooling fluid passes through these sections continuously, in each section always flowing only around the outer wall portion of the housing sleeve within the flow path. Since the cooling fluid flows continuously around the housing sleeve, but in each section always flows only around the outer wall portion and not around the entire outer wall, the temperature difference between the battery cells can be reduced. In a preferred embodiment, the housing sleeve is manufactured from a monopolymer or copolymer thermoplastic material, such as polyolefin, polyvinylidene fluoride, polytetrafluoroethylene, polycondensate, acrylonitrile butadiene styrene, or fluoroelastomer, preferably under the action of heat, and stretched to expand its free inner diameter.To improve thermal conductivity and / or reduce electrical conductivity and simultaneously increase dielectric strength, the material may include fillers, such as carbon black and / or inorganic fillers, particularly mineral fillers. The stretching process can be terminated by subsequent cooling, thereby maintaining the enlarged free inner diameter of the housing sleeve under internal structural stress. After insertion of the battery cells, the housing sleeve is heated so that the structural stress is released and the inner diameter shrinks, thereby causing the housing sleeve to contact the periphery of the battery cells. In one embodiment, a wall portion constitutes the wall of a substrate, and a plurality of receiving openings are perforated in this wall. This provides a temperature control device for a battery system having a substrate and a plurality of housing sleeves for battery cells arranged in a flow path, wherein the wall of the substrate has receiving openings leading to the housing sleeves, and preferably the housing sleeves are formed from the wall of the substrate.

[0008] To enable the use of conductive fluids, it is proposed that the housing sleeve be an electrical insulator. While the housing sleeve does indeed constitute a physical barrier that, in principle, worsens heat transfer between the battery cell and the cooling fluid, this apparent drawback has been found to enable the use of conductive cooling fluids without increasing the risk of short circuits in the temperature control device. Specifically, conductive cooling fluids typically have a higher thermal conductivity than electrically insulating cooling fluids, thus adequately compensating for the difficult heat transfer. Overall, more thermal energy can be transferred from the battery cell to the cooling fluid via the housing sleeve than would be possible to transfer to the electrically insulating cooling fluid without the housing sleeve. This effect is further enhanced when using exposed battery cells, i.e., when their shells are at least partially removed to establish electrical contact, because the shells also make it difficult for thermal energy to escape from within the battery cell, thereby enabling improved heat transfer in addition to easier electrical contact.

[0009] When a battery cell is inserted into a housing sleeve while forming a press-fit section, both the insertion of the battery cell and the heat transfer to the cooling fluid in its housing and flow path can be improved. As a result of these measures, the battery cell can be pushed into the housing sleeve. Furthermore, there is no need to provide another part, such as a cover or locking device to fix the battery cell in the housing sleeve, because, if the diameter of the housing sleeve is appropriately selected, the press-fit section will fix the battery cell in a friction-engagement and / or mating manner. Press-fitting causes the battery cell to be in close contact with the housing sleeve at least partially on the shell side, thereby facilitating heat transfer to the cooling fluid through the housing sleeve. To form the press-fit section, the diameter of the housing sleeve before insertion of the battery cell can be at least partially smaller than the diameter of the battery cell. Preferably, the diameter of the housing sleeve decreases starting from the receiving opening, so that the press-fit section can be easily formed by pushing the battery cell in when it is fitted, and the housing sleeve is in close contact circumferentially with the battery cell inserted. In a preferred embodiment, each housing sleeve is provided with at least one ventilation channel on the shell side, through which air leaking from the housing sleeve during press-fitting can be discharged. This ventilation channel can be positioned within the housing sleeve, so that it induces turbulence in the cooling fluid as it flows around the housing sleeve, thereby further improving heat transfer from the battery cells to the cooling fluid through the housing sleeve.

[0010] To facilitate electrical contact of battery cells and to securely fix them mechanically, it is proposed that the housing sleeve be provided with a sleeve bottom on the opposite side of the receiving opening. The sleeve bottom constitutes a stopper for the battery cell along its longitudinal axis, thereby fixing the battery cell in a fitted manner in this direction. Thus, a uniform maximum housing depth for the battery cells in each housing sleeve can be easily defined. As a result, each battery cell protrudes the same distance from its corresponding receiving opening, which facilitates electrical contact, for example, by a contact plate. In a special embodiment, each housing sleeve is provided with a hole in its sleeve bottom through which, for example, the poles of the battery cell can be contacted, or the hole is used as a degassing valve.

[0011] In particular, to simplify mechanical and electrical access to the battery cells inserted within the housing sleeve without adversely affecting the flow path in terms of fluid tightness, the sleeve bottom can constitute the outer wall portion of the base. As a result of these measures, the sleeve bottom is not located within the flow path, and thus operations at the sleeve bottom do not involve leakage within the flow path and / or electrical connections between the cooling fluid and the battery cells. Therefore, it can be easily operated from outside the sleeve bottom without adversely affecting the functionality of the temperature control device. For example, if a hole is provided in the sleeve bottom for electrical contact, this contact can be easily made via an external component, such as a contact plate, that does not need to be inserted into the flow path.

[0012] For example, to minimize damage to the temperature control device caused by battery cell abnormalities such as thermal runaway, it is proposed that the sleeve bottom be equipped with a degassing valve. As a result of these measures, the kinetic energy released through the gas released during an abnormality can be directed out through the degassing valve at the sleeve bottom rather than being transmitted to the shell side of the containment sleeve. Depending on how the temperature control device is manufactured, the released gas can be guided into a flow path and discharged together with the cooling medium. Preferably, the sleeve bottom constitutes the outer wall portion of the substrate so that the outflowing gas is discharged from the temperature control device without reaching the flow path and contaminating the cooling fluid. In the simplest case, the degassing valve is a target rupture point at the sleeve bottom. In a preferred embodiment, the degassing valve is a mechanical valve, thereby preventing damage to the temperature control device even when the battery cell is degassed. In a particularly simple embodiment, the degassing valve is a rupture membrane.

[0013] If the housing sleeve is formed from the wall portion of the base body, the number of components in the temperature control device, and therefore the number of seals required, can be minimized. In relation to the present invention, "formed" means that the housing sleeve is composed from the wall portion in a single forming step. As a result of these measures, at least the wall portion of the base body and the housing sleeve can be formed integrally, thereby eliminating the need for these components to be joined together or for fluid-tight seals to be provided. Another advantage is that forming reduces the wall thickness within the housing sleeve region, thereby establishing good heat transfer from the battery cells to the cooling fluid through the housing sleeve. In the simplest case, the entire temperature control device can be integrally formed from a hollow body by manufacturing the housing sleeve by press working, thereby automatically forming the flow path inside the base body without any further manufacturing technical measures. Preferably, the housing sleeve is formed such that the sleeve bottom is also formed during the manufacturing step. The forming step may be deformation. The housing sleeve can be formed, for example, by deep drawing. Multiple housing sleeves can be formed from the wall portion, thereby forming at least two housing sleeves integrally with one another. In this way, the containment sleeve can be easily inserted into the flow path. When the wall portion having the containment sleeve forms a removable wall of the base, an easily assembled temperature control device can be obtained.

[0014] Since common manufacturing and molding methods can be easily used to manufacture temperature control devices, it is proposed that the substrate consists of two parts that can be fluid-tightly bonded to each other. This allows the geometric shapes of both parts to be designed so that they can be easily manufactured. This allows manufacturing steps for parts of the substrate that are difficult to access in the assembled state, such as flow channels, to be easily carried out before the substrate is fluid-tightly assembled. As a result of these measures, for example, flow dividers can be easily inserted before assembly. Thus, the two parts can be manufactured, for example, from two plates that are joined to each other after molding. Fluid-tight bonding can be established by material bonding and / or using seals. Particularly simple manufacturing conditions are obtained when the parts, which are material-bonded to each other by welding, are manufactured from thermoplastic plastics.

[0015] Preferably, one sub-part forms a wall portion with a receiving opening that defines a flow path together with the second sub-part. In the simplest case, the wall portion may consist of only one plate that can be easily processed by conventional manufacturing processes such as press working or deep drawing. Thus, the receiving opening, and preferably the housing sleeve, can be created in the first sub-part without requiring much effort. The second sub-part is configured complementary to the first sub-part so that the two sub-parts define a flow path after assembly. For this reason, the second sub-part can be configured substantially in a trough shape, which also facilitates manufacturing by press working, deep drawing, etc.

[0016] Another two-part configuration, which is easy to manufacture and particularly mechanically stable, is obtained when the end portion of the housing sleeve opposite the receiving opening is fluid-tightly coupled to the second portion. As a result of these measures, the housing sleeve does not necessarily need to have a sleeve bottom, thereby simplifying manufacturing. The fluid-tight coupling between the end portion of the housing sleeve and the second portion not only provides a fluid-tight flow path, but also reinforces the entire temperature control device by coupling the two portions together in each housing sleeve. If one portion forms the housing sleeve, its end portion can be welded to the second housing, for example. Otherwise, the housing sleeve can be welded to both portions. Preferably, the second portion forms the bottom for the housing sleeve, and this bottom performs the same function as the sleeve bottom.

[0017] Despite the low cost of manufacturing the device, it is proposed that each battery cell be provided with a housing sleeve to ensure adequate protection of the battery cells in the event of thermal runaway. In this way, the battery cells are spatially shielded from one another, and the housing sleeve constitutes a protective barrier between adjacent battery cells. In particular, if the housing sleeve completely encloses the battery cell, an effective protective barrier for shielding a defective battery cell can be achieved. Preferably, the battery cells are fluid-tightly sealed to one another by the housing sleeve to prevent the escaped hot gas from spreading toward adjacent battery cells.

[0018] A favorable condition for simple manufacturing can be achieved by forming the housing sleeve in a hollow cylindrical shape, particularly having a circular base. In this way, corners and edges that result in inaccurate results can be reduced, especially during forming processes such as deep drawing.

[0019] The drawings illustrate the subject matter of the present invention in an illustrative manner. [Brief explanation of the drawing]

[0020] [Figure 1]Isometric view of the temperature control device according to the present invention with a battery cell inserted [Figure 2] Exploded view of the temperature control device according to the invention of FIG. 1 [Figure 3] Enlarged view of a cross-section taken along line III-III of FIG. 1

Mode for Carrying Out the Invention

[0021] The temperature control device according to the present invention has a base body 1 and a plurality of receiving sleeves 2 for battery cells 3. The base body 1 has an inlet 5 and an outlet 6 and forms a fluid-tight flow path 4 filled with a cooling fluid flowing around the receiving sleeve 2 during operation. Generally, an efficient cooling fluid, that is, a cooling fluid that ensures good heat transfer from the battery cell 3 to the cooling fluid, is conductive. However, when the receiving sleeve 2 is an electrical insulator, such a cooling fluid can still be used. This advantage of improved heat transfer outweighs the disadvantage of the receiving sleeve 2 as an additional intermediate layer between the battery cell 3 and the cooling fluid. As shown in the figure, when the battery cell 3 is press-fitted while the receiving sleeve 2 is inserted so that the receiving sleeve 2 contacts the entire circumference of the battery cell shell, the above-mentioned disadvantage is further reduced by the large interaction surface available for heat transfer. In order to discharge the air present in the receiving sleeve 2 during press-fitting from the receiving sleeve 2, ventilation channels (not shown) can be provided on the shell side of the receiving sleeve 2, and these ventilation channels preferably also induce turbulent flow in the cooling fluid in the flow path 4 in order to improve heat transfer. When the receiving sleeve 2 is formed from the wall portion 8 of the base body 1, for example, by deep drawing as shown in the figure, this results in a thinning of the wall of the receiving sleeve 2 compared to the thickness of the wall portion 8 due to materials and manufacturing in addition to simplified manufacturing, thereby reducing the heat insulation properties of the receiving sleeve 2 as desired, but providing another advantage that the required electrical insulation remains unaffected.

[0022] To accommodate the battery cell 3 within the receiving sleeve 2, the battery cell is pushed into the receiving sleeve 2 through the receiving opening 7. These receiving openings 7 are, according to the present invention, openings within the wall portion 8 of the base body 1, and preferably include a sleeve bottom 9 on the side opposite to the receiving opening 7, and this sleeve bottom is used as a stopper for the battery cell 3. Further, the sleeve bottom 9 can constitute the outer wall portion of the base body 1, whereby the inserted battery cell 3 remains accessible through the sleeve bottom 9. Therefore, in case of an abnormality, the gas leaking from the battery cell 3 is led outside the temperature control device through the degassing valve 10, and in particular, it is possible to prevent these gases from contaminating the cooling fluid within the flow path 4.

[0023] The base body 1 of the illustrated embodiment is composed of two partial bodies 11, 12 in order to facilitate manufacturing. These two partial bodies 11, 12 are fluid-tightly joined to each other, for example, by welding. One partial body 11 forms a wall portion 8 provided with a receiving opening 7 that defines the flow path 4 together with the second partial body 12. Regardless of whether the sleeve bottom 9 is provided for the receiving sleeve 2, the terminal portion 13 of the receiving sleeve 2 can be fluid-tightly joined to the second partial body 12, which reinforces the temperature control device.

[0024] Another advantage when using the two partial bodies 11, 12 is that the shunt 14 can be used without high manufacturing technical effort. By the shunt 14, the inlet 5 and the outlet 6 can be arranged on the same end face of the base body 1, but nevertheless, the flow around all the battery cells 3 is uniform. However, a greater advantage is that the shunt 14 divides the flow path 4 into two parallel regions through which the cooling fluid continuously passes. The cooling fluid only flows around either the upper half or the lower half of the battery cell 3 in each region, but passes through each battery cell 3 twice, thereby reducing the temperature gradient between the battery cell 3 and the cooling fluid at the outlet 6, and thus reducing the temperature difference between the battery cells 3 within the temperature control device.

[0025] In particular, Figure 2 shows that each battery cell 3 can be equipped with its own housing sleeve 2, and that the housing sleeve 2 completely encloses the battery cell 3. In this way, the battery cells 3 can be fluidly sealed to one another by the housing sleeve 2.

[0026] In a preferred embodiment, the housing sleeves 2 are formed integrally with each other. Thus, the wall portion 8—from which the housing sleeves 2 are formed—can form a wall for the base 1 that connects the housing sleeves 2 to each other.

[0027] Particularly favorable manufacturing conditions with respect to the molding process are obtained when the housing sleeve 2 is formed in a hollow cylindrical shape, especially having a circular bottom surface.

Claims

1. A temperature control device for a battery system having a base body (1) and a plurality of housing sleeves (2) for battery cells (3) arranged in a flow path (4), wherein a receiving opening (7) leading to the housing sleeves (2) is drilled in the wall portion (8) of the base body (1), A temperature control device characterized in that the housing sleeve (2) is formed from the wall portion (8) of the base body (1).

2. The temperature control device according to claim 1, characterized in that the housing sleeve (2) is an electrical insulator.

3. The temperature control device according to claim 1 or 2, characterized in that the battery cell (3) is inserted into the housing sleeve (2) while forming a press-fit portion.

4. A temperature control device according to any one of claims 1 to 3, characterized in that the receiving sleeve (2) has a sleeve bottom (9) on the opposite side of the receiving opening (7).

5. The temperature control device according to claim 4, characterized in that the sleeve bottom (9) constitutes the outer wall portion of the base (1).

6. The temperature control device according to claim 4 or 5, characterized in that the sleeve bottom (9) is provided with a deaeration valve (10).

7. A temperature control device according to any one of claims 1 to 6, characterized in that the base body (1) is composed of two sub-parts (11, 12) that can be fluidly coupled to each other.

8. The temperature control device according to claim 7, characterized in that one sub-body (11) together with the second sub-body (12) forms a wall portion (8) with a receiving opening (7) that defines a flow path (4).

9. The temperature control device according to claim 7 or 8, characterized in that the end portion (13) of the receiving sleeve (2) opposite to the receiving opening (7) is liquid-tightly coupled to the second sub-body (12).

10. A temperature control device according to any one of claims 1 to 9, characterized in that one housing sleeve (2) is provided for each battery cell (3).

11. A temperature control device according to any one of claims 1 to 10, characterized in that the housing sleeve (2) completely encloses the battery cell (3).

12. A temperature control device according to any one of claims 1 to 11, characterized in that the battery cells (3) are fluid-tightly sealed to one another by a housing sleeve (2).

13. A temperature control device according to any one of claims 1 to 12, characterized in that at least two housing sleeves (2) are integrally formed with respect to each other.

14. The temperature control device according to any one of claims 1 to 13, characterized in that the housing sleeve (2) is formed in the shape of a hollow cylinder.

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