INTEGRATED COOLING ELEMENT FOR A BATTERY MODULE

Abstract

A housing for at least one heat-releasing element (100), for example a battery element in an electric vehicle, comprises: a housing wall (200), a holder (300) which is joined to the housing wall (200) for accommodating the at least one heat-releasing element (100) and a cooling body (400) which is arranged on a side of the housing wall (200) opposite the holder (300) and is joined to the housing wall (200).

The housing wall (200), the holder (300) and the cooling body (400) are together present as one-piece component, wherein the cooling body (400) has at least one channel (500) for a cooling medium and at least a subregion of the cooling body (400) consists of a first thermoplastic polymer composition having a thermal conductivity determined in accordance with ASTM E1461-01 of ≥0.2 W/(m K).

Claims

1. A housing for at least one heat-releasing element, comprising: a housing wall, a holder which is joined to the housing wall for accommodating the at least one heat-releasing element, and a cooling body which is arranged on a side of the housing wall opposite the holder and is joined to the housing wall, wherein the housing wall, the holder and the cooling body are together present as one-piece component, wherein the cooling body has at least one channel for a cooling medium and at least a subregion of the cooling body consists of a first thermoplastic polymer composition having a thermal conductivity determined in accordance with ASTM E1461-01 of ≥0.2 W/(m K).

2. The housing of claim 1, wherein the first thermoplastic polymer composition comprises a polymer selected from the group consisting of polycarbonate, polyamide, acrylonitrile-butadiene-styrene, polyphenylene sulfide, polypropylene and a mixture of at least two of the abovementioned polymers.

3. The housing of claim 2, wherein the first thermoplastic polymer composition comprises a polycarbonate which has a melt volume rate MVR of from 8 to 20 cm.sup.3/(10 min), determined in accordance with ISO 1133-1:2012-03 (300° C., 1.2 kg).

4. The housing of claim 1, wherein the first thermoplastic polymer composition further comprises a filler from the group consisting of aluminum oxide, boron nitride, silicon oxide, kaolin, talc or a mixture of at least two of the abovementioned fillers.

5. The housing of claim 1, wherein the first thermoplastic polymer composition has a modulus of elasticity determined in accordance with ISO 527-1/-2 of from ≥2000 to ≤3500 MPa or an Izod impact toughness determined in accordance with ISO 180/A at 23° C. of from ≥5 to ≤60 kJ/m2.

6. The housing of claim 1, wherein a) the at least one channel for the cooling medium is a channel which is open to the surroundings and the cooling medium is air or wherein b) the at least one channel is a closed channel and the cooling medium is a liquid.

7. The housing of claim 1, wherein the material of the housing contains ≥90% by weight, based on the total weight of the housing, of the first thermoplastic polymer composition.

8. The housing of claim 1, wherein the material of the housing further comprises a second thermoplastic polymer composition which is different from the first thermoplastic polymer composition and is present in regions of the housing in which the first thermoplastic polymer composition is absent.

9. The housing of claim 8, wherein the second thermoplastic polymer composition comprises polycarbonate, polyimide, acrylonitrile-butadiene-styrene copolymers, polyphenylene sulfide, polypropylene or a mixture of at least two of the abovementioned polymers.

10. The housing of claim 9, wherein the second thermoplastic polymer composition further comprises a flame retardant.

11. The housing of claim 1, wherein the cooling body has a plurality of channels which are formed by fins.

12. A process for producing the housing of claim 1, comprising the step of producing the housing wall, the holder (300) and the cooling body (400) as one-piece component in an injection molding process.

13. A system comprising the housing of claim 1 and a heat-releasing element which is accommodated in the holder of the housing.

14. The system of claim 13, wherein the heat-releasing element is an electrochemical store for electric energy or an electrochemical source of electric energy.

Description

[0026] The present invention will now be further illustrated with the aid of the following figures, but without being restricted thereto.

[0027] FIG. 1 shows a system according to the invention.

[0028] FIG. 2 shows a further system according to the invention.

[0029] FIG. 1 schematically shows a system according to the invention having a housing according to the invention which has accommodated heat-releasing elements 100, for example rechargeable batteries, in corresponding holders 300. The lower part of FIG. 1 shows the system in plan view and the upper part shows a sectional view along the line D-D drawn-in in the lower part.

[0030] The housing comprises, as one-piece component, the housing wall 200, a plurality of holders 300 and a cooling body 400. The holders 300 enclose the heat-releasing elements 100 at their upper and lower sections and thereby fix them in place. The cooling body 400 is arranged on a side of the housing wall 200 opposite the holders 300, in the present case on the underside of the housing. Owing to the one-piece nature, the formulation according to which the holders 300 go over into the housing wall 200 and the housing wall 200 goes over into the cooling body 400 at selected sections is equivalent.

[0031] The cooling body 400 has at least one channel 500 for a cooling medium. Preference is given to a) the at least one channel 500 for the cooling medium being a channel which is open to the surroundings and the cooling medium being air. This is depicted in FIG. 1. The side walls of the channel 500 can thus also be described as cooling fins. In an alternative b), the at least one channel 500 is a closed channel and the cooling medium is a liquid. Water cooling, for example, can be realized in this way.

[0032] In a further embodiment depicted in FIG. 2, the cooling body 400 is in two parts and has a subregion composed of a first thermoplastic composition and a subregion composed of a second thermoplastic composition, with the subregion composed of the first thermoplastic composition being planar on its side facing away from the holder 300 and this planar side being joined by substance-to-substance bonding to a region composed of a second thermoplastic composition 600.

[0033] In a further embodiment, the material of the housing comprises ≥90% by weight, based on the total weight of the housing, of the first thermoplastic polymer. Fillers and other polymer additives which are incorporated or have already been incorporated in the compounding of the polymer are included in this proportion by weight of the polymer (“polymer composition”). This proportion is preferably ≥95% by weight and more preferably ≥99% by weight, based on the total weight of the housing. The housing can thus be characterized as “one-component housing”. The use of only one material enables manufacturing steps to be saved.

[0034] In a further embodiment, the material of the housing further comprises a second thermoplastic polymer composition which is different from the first thermoplastic polymer composition and is present in sections of the housing at which the first thermoplastic polymer composition is absent. What has been said in respect of the first polymer composition also applies in principle to the second thermoplastic polymer composition. The polymer of the second thermoplastic polymer composition is preferably the same as the first, but with the thermally conductive fillers being decreased in amount or removed. In such a “two-component housing”, manufacturing requirements can generally be satisfied by thermoplastics which flow differently in the injection molding process being used at places on the housing at which good thermal conductivity is of lesser importance. The first and second thermoplastic polymer compositions together form a substance-to-substance bond at their interfaces.

[0035] In a further embodiment, the polymer of the second thermoplastic polymer composition is selected from among polycarbonate, polyamide, acrylonitrile-butadiene-styrene copolymers, polyphenylene sulfide, polypropylene or a mixture of at least two of the abovementioned polymers. To avoid repetition, reference may be made to what has been said above in respect of the first polymer composition.

[0036] In a further embodiment, the second thermoplastic polymer composition contains a flame retardant. Suitable flame retardants are, in particular, phosphates such as BDP (bisphenol A bis(diphenylphosphate)). Further suitable flame retardants are phosphazenes such as cyclic and linear phosphazenes of the formulae (I) and (II):

##STR00001##

where R.sup.1, R.sup.2 are identical or different and are each an alkyl, cycloalkyl, aryl or alkylaryl, R.sup.3, R.sup.4 are identical or different and are each alkyl, cycloalkyl, aryl or alkylaryl, R.sup.5 is —N═P(OR.sup.3).sub.3, —N═P(OR.sup.4).sub.3, —N═P(O)OR.sup.3 or —N═P(O)OR.sup.4, R.sup.6 is —N═P(OR.sup.3).sub.4, —N═P(OR.sup.4).sub.4, —N═P(O)(OR.sup.3).sub.2 or —N═P(O)(OR.sup.4).sub.2, a is an integer in the range from 3 to 25 and b is an integer in the range from 3 to 10 000.

[0037] Among the cyclic phosphazenes of the formula (I) to be used according to the invention, preference is given to using those in which a in formula (I) is an integer in the range from 3 to 8, particularly preferably an integer in the range from 3 to 5.

[0038] Among the chain-like phosphazenes of the formula (II) to be used according to the invention, preference is given to using those in which b is an integer in the range from 3 to 1000, particularly preferably in the range from 3 to 100, very particularly preferably in the range from 3 to 25.

[0039] Very particular preference is given to using cyclic phenoxyphosphazenes as are obtainable from, for example, Fushimi Pharmaceutical Co. Ltd, Kagawa, Japan, under the name Rabitle® FP110 [CAS No. 1203646-63-2] or, when a=3, then 2,2,4,4,6,6-hexahydro-2,2,4,4,6,6-hexaphenoxytriazatriphosphorines [CAS No. 1184-10-7].