HEAT DISSIPATING ELEMENT

Abstract

A heat dissipating element contains graphite and a microencapsulated phase-change material (PCM). The heat dissipating element is provided with a Li-ion battery for a car, truck, or pedelec to control the temperature of the battery. The heat dissipating element allows the capacitance of the Li-ion battery to remain at a higher level and more energy to be available for heating the passenger compartment.

Claims

1. A method for controlling a temperature of a Li-ion battery in a car, a truck, or a pedelec, the method comprising: providing at least one heat dissipating element containing a graphite and a microencapsulated phase-change material (PCM).

2. The method according to claim 1, wherein the graphite is selected from the group consisting of a natural graphite, a synthetic graphite, and an expanded graphite, or a mixture thereof.

3. The method according to claim 1, wherein the microencapsulated PCM is selected from the group consisting of a sugar alcohol, a paraffin, a wax, a salt hydrate, and a fatty acid, or a mixture thereof.

4. The method according to claim 1, wherein the microencapsulated PCM has a melting range between 20 C. and 130 C.

5. The method according to claim 4, wherein the microencapsulated PCM has a size of less than or equal to 5 mm.

6. The method according to claim 1, wherein the at least one heat dissipating element is configured as a plate or a foil, and wherein at least one layer comprising the microencapsulated PCM is provided on the plate or the foil.

7. The method according to claim 1, wherein the at least one heat dissipating element is configured as a graphite foil or a graphite plate and includes at least one applied layer of the microencapsulated PCM.

8. The method according to claim 6, wherein the at least one layer additionally comprises a binder, and wherein a content of the microencapsulated PCM in the at least one layer provided on the plate or the foil and comprising the graphite and the microencapsulated PCM is 10% to 98% by weight.

9. The method according to claim 7, wherein the at least one layer additionally comprises a binder, and wherein a content of the microencapsulated PCM in the at least one layer provided on the graphite foil or the graphite plate and comprising the graphite and the microencapsulated PCM is 10% to 98% by weight.

10. The method according to claim 6, wherein a thickness of the at least one layer comprising the microencapsulated PCM is less than 5 mm.

11. The method according to claim 6, wherein the plate has a thickness of more than 1 mm up to 5 mm.

12. The method according to claim 6, wherein the foil has a thickness of 10 m to 1 mm.

13. The method according to claim 1, wherein a thermal conductivity of the heat dissipating element is above 150 W/(m.Math.K).

14. A heat dissipating element provided for the method according to claim 1, wherein the heat dissipating element comprises graphite and microencapsulated PCM, wherein the heat dissipating element is configured as a plate or foil, and wherein at least one layer comprising the microencapsulated PCM is applied to the plate or the foil.

15. The method according to claim 1, whereinduring slow coolingat least a part of the phase transition of the microencapsulated PCM takes place in a temperature range of 20 C. to 0 C.

16. The method according to claim 3, wherein the microencapsulated PCM has a melting range between 20 C. and 130 C.

17. The method according to claim 7, wherein a thickness of the at least one layer comprising microencapsulated PCM is less than 5 mm.

18. The method according to claim 7, wherein the graphite plate including the microencapsulated PCM has a thickness of more than 1 mm up to 5 mm.

19. The method according to claim 7, wherein the graphite foil has a thickness of 10 m to 1 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In the following, the present disclosure is described, purely by way of example, by way of exemplary embodiments and with reference to the accompanying drawings. The disclosure is not limited by the drawings.

[0046] FIG. 1 is a cross section of a heat dissipating element;

[0047] FIG. 2 is a cross section of a heat dissipating element; and

[0048] FIG. 3 is a cross section of a heat dissipating element.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0049] FIG. 1 shows a heat dissipating element containing a graphite foil (1) and a layer, applied thereto, of microencapsulated PCM (3) comprising a binder (2).

[0050] FIG. 2 shows a heat dissipating element as a plate containing graphite (4), microencapsulated PCM (3) and binder (2).

[0051] FIG. 3 shows a heat dissipating element as a plate containing graphite (4), microencapsulated PCM (3), and binder (2) and a layer, applied thereto, containing microencapsulated PCM (3) and binder (2).

[0052] In the following, the present disclosure is described by way of exemplary embodiments, the exemplary embodiments not forming any restriction on the disclosure.

Exemplary Embodiment 1

[0053] A graphite foil having a thickness of 150 m and a density of 1.3 g/cm.sup.3 (commercially available from SGL Carbon GmbH) is coated on one side with a mixture of microencapsulated PCM (Micronal 28, BASF), a rubber binder, and a dispersant.

[0054] The composition of the mixture is 24.5 g water, 1.5 g Litex SX 1014, 10.4 g microencapsulated PCM (Micronal 28, BASF), and 0.1 g polyvinyl pyrrolidone (PVP).

[0055] The mixture is dispersed in an ultrasonic bath and applied on a coating system using a doctor blade, blade height 500 m. The result after drying is a 200 m thin layer on the graphite foil.

Exemplary Embodiment 2

[0056] A graphite foil having a thickness of 150 m and a density of 1.3 g/cm.sup.3 (commercially available from SGL Carbon GmbH) is coated on both sides with a mixture of microencapsulated PCM (Micronal 28, BASF), 5 m fine graphite powder, a rubber binder, and a dispersant.

[0057] The composition of the mixture is 31.5 g water, 2 g Litex SX 1014, 20 g graphite powder, 10.4 g microencapsulated PCM (Micronal 28, BASF), and 0.1 g polyvinyl pyrrolidone (PVP).

[0058] The mixture is dispersed in an ultrasonic bath and applied on a coating system at 55 C. using a doctor blade, blade height 600 m. The result after drying is a 400 m thin layer on the graphite foil.

Exemplary Embodiment 3

[0059] A plate comprising microencapsulated PCM (Micronal 28, BASF) for use as a heat dissipating element. The composition of the plate is as follows: 135 g graphite powder (50 m), 67.5 g graphite powder (150 m), 810 g microencapsulated PCM (Micronal 28, BASF), 337.5 g Elastosil M4642A as a binder, and Elastosil M4642 B as a curing agent.

[0060] The individual mixture constituents are added in succession to an EIRICH mixer and mixed for a total of 10 minutes.

[0061] Subsequently, the raw compound is pressed into a 5 mm thick plate in a press.

Exemplary Embodiment 4

[0062] A plate comprising microencapsulated PCM (Micronal 28, BASF) for use as a heat dissipating element. The composition of the plate is as follows: 135 g graphite powder (50 m), 67.5 g graphite powder (150 m), 810 g microencapsulated PCM (Micronal 28, BASF), 337.5 g Elastosil M4642A as a binder, and Elastosil M4642 B as a curing agent.

[0063] The individual mixture constituents are added in succession to an EIRICH mixer and mixed for a total of 10 minutes and pressed into a 5 mm thick plate.

[0064] Subsequently, the plate is coated on one side with a mixture of microencapsulated PCM (Micronal 28, BASF), a rubber binder, and a dispersant.

[0065] The composition of the mixture is 24.5 g water, 1.5 g Litex SX 1014, 10.4 g microencapsulated PCM (Micronal 28, BASF), and 0.1 g polyvinyl pyrrolidone (PVP).

[0066] The mixture is dispersed in an ultrasonic bath and applied on a coating system using a doctor blade, blade height 500 m. The result after drying is a 200 m thin layer.

[0067] The foregoing description of the exemplary embodiments of the disclosure illustrates and describes the present invention. Additionally, the disclosure shows and describes only the exemplary embodiments but, as mentioned above, it is to be understood that the disclosure is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art.

[0068] The term comprising (and its grammatical variations) as used herein is used in the inclusive sense of having or including and not in the exclusive sense of consisting only of. The terms a and the as used herein are understood to encompass the plural as well as the singular.

[0069] All publications, patents and patent applications cited in this specification are herein incorporated by reference, and for any and all purposes, as if each individual publication, patent or patent application were specifically and individually indicated to be incorporated by reference. In the case of inconsistencies, the present disclosure will prevail.

LIST OF REFERENCE NUMERALS

[0070] 1 Graphite foil [0071] 2 Binder [0072] 3 Microencapsulated PCM [0073] 4 Graphite [0074] 5 Heat dissipating element