Moldable mass containing graphite and phase change material, process for producing a molding from the mass, and production methods of using the molding

Abstract

A moldable mass contains graphite and a phase change material (PCM). The moldable mass further contains a binder and microcapsules having the PCM. A process produces a molding from the moldable mass, and the molding is used to produce various products such as cooling elements, battery temperature control elements, cooling elements for vehicle cabins, electronic components, and motors.

Claims

1. A battery configuration, comprising: a battery cell pack; and a cooling element for maintaining a constant temperature of said battery cell pack, said cooling element having a form-fitting connection with said battery cell pack, said cooling element containing: graphite; a binder selected from the group consisting of epoxy resins and fluoropolymers; and microcapsules containing a phase change material (PCM).

2. The battery configuration according to claim 1, wherein: said graphite is 1 to 60 wt. %; said microcapsules containing said PCM is 35 to 95 wt. %; and said binder is 1 to 50 wt. %.

3. The battery configuration according to claim 1, wherein said graphite is selected from the group consisting of natural graphite, graphite expandate, comminuted graphite film, synthetic graphite and any desired combination thereof.

4. The battery configuration according to claim 3, wherein: said natural graphite has particle sizes of between 149 and 840 m; said graphite expandate has particle sizes of between 5 and 30 mm; said comminuted graphite film has particle sizes of between 5 and 1200 m; and said synthetic graphite has particle sizes of between 10 and 600 m.

5. The battery configuration according to claim 1, wherein: said microcapsules have a size from 1 to 1000 m; and said battery cell pack has cold sensitive lithium ion batteries.

6. The battery configuration according to claim 1, wherein said PCM is selected from the group consisting of paraffins, salt hydrates, sugar alcohols and fatty acids.

7. The battery configuration according to claim 1, further comprising at least one additive selected from the group consisting of surfactants, dispersants, alkylbenzenesulphonate and polyvinylpyrrolidone.

8. A cooling element for maintaining a temperature of a battery cell pack, said cooling element comprising: a molded cooling element body for maintaining a constant temperature of the battery cell pack, said molded cooling element body having a form-fitting connection with the battery cell pack, said molded cooling element body containing: graphite; a binder selected from the group consisting of epoxy resins and; and microcapsules containing a phase change material (PCM).

9. The cooling element according to claim 8, wherein: said graphite is 1 to 60 wt. %; said microcapsules containing said PCM is 35 to 95 wt. %; and said binder is 1 to 50 wt. %.

10. The cooling element according to claim 8, wherein said graphite is selected from the group consisting of natural graphite, graphite expandate, comminuted graphite film, synthetic graphite and any desired combination thereof.

11. The cooling element according to claim 10, wherein: said natural graphite has particle sizes of between 149 and 840 m; said graphite expandate has particle sizes of between 5 and 30 mm; said comminuted graphite film has particle sizes of between 5 and 1200 m; and said synthetic graphite has particle sizes of between 10 and 600 m.

12. The cooling element according to claim 8, wherein: said microcapsules have a size from 1 to 1000 m; and said molded cooling element body is L-shaped.

13. The cooling element according to claim 8, wherein: aid PCM is selected from the group consisting of paraffins, salt hydrates, sugar alcohols and fatty acids; and said molded cooling element body is formed in a curved shape.

14. The cooling element according to claim 8, further comprising at least one additive selected from the group consisting of surfactants, dispersants, alkylbenzenesulphonate and polyvinylpyrrolidone.

15. A method of producing a battery configuration, which comprises the steps of: providing a battery cell; forming a molded cooling element body containing a moldable mass having graphite, a binder selected from the group consisting of epoxy resins and fluoropolymers, and microcapsules having a phase change material (PCM); and connecting the cooling element to the battery cell via a form-fitting connection.

16. A configuration, comprising: a heat producing element selected from the group consisting of power electronics, electric motors, charging devices, and hub motors; and a cooling element for maintaining a constant temperature of said heat producing element, said cooling element having a form-fitting connection with said heat producing element, said cooling element containing: graphite; a binder selected from the group consisting of epoxy resins and fluoropolymers; and microcapsules containing a phase change material (PCM).

17. The cooling element according to claim 8, further comprising at least one further binder selected from the group consisting of geopolymers, water-soluble sodium, potassium silicates, phenol resins, silicone resins, polyester resins, thermoplastics and polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) To produce a mass according to the invention, initially 2 kg graphite expandate having a density of 0.1 g/l are produced by conventionally expanding graphite salt. As the microcapsulated PCM, 7 kg MICRONAL from BASF S.E., having a capsule size of between 2 and 20 m, are stirred in 1 kg phenol resin as a dispersant. The resulting dispersion is mixed in an Eirich mixer with the graphite expandate for 0.5 h. Further, 120 g sodium dodecylbenzylsulphonate are added as a wetting agent, so as to increase the flowability of the resulting molding mass according to the invention.

(2) Part of the mass is placed in a stamping machine and pressed at 300 MPa into a shape in the form of the base of the stamping machine, which is in the form of a curved cooling element. The phenol resin, which also acts as a binder for the mass, cures at temperatures of 180 C. The resulting molding is removed and is used as a cooling element of a lorry vehicle cabin. As a result of the high mechanical strength thereof, the element having a size of 6060 cm can be installed self-supporting as a wall element in the vehicle cabin. It can store heat and cold and emit them into the cabin. As a result of the graphite content, rapid charging and discharging are achieved. The PCM stores the heat or cold and can ensure uniform temperature control as a result of the solid-liquid phase change thereof, without even dissipating heat out of the cabin. As a result of the paraffin being capsulated as PCM, no flammable fluid escapes in the event of an accident, but instead the molten paraffin remains safely enclosed by a polymethylmethacrylate (PMMA) casing.

(3) Another part of the mass is placed in an injection-molding machine and is sprayed at high pressure into heated moulds which are in the shape of cooling elements for secondary battery systems, in this example lithium ion batteries. Even complicated geometries, for example having sharp edges of angularly shaped battery cells, can be produced according to the invention. The for example L-shaped molding fits onto a battery cell of this type in a positive fit.

(4) According to a further variant of the embodiment, a sodium silicate solution is used as an inorganic binder and natural graphite is used as the graphite. These are processed together with the PCM-filled microcapsules from BASF, using a mechanical heavy-duty mixer, and the mass is not processed directly into moldings, but instead is compressed and sent to a processor, for example an aeroplane manufacturer, where the mass is injected on-site into the aeroplane structure at a predetermined place, for example the internal lining.