FLEXIBLE COMPOSITES CONTAINING GRAPHITE AND FILLERS
Flexible composites of graphite leaf, containing fillers other than natural graphite, which has higher thermal conductivity than conventional 100% natural graphite based graphite sheet/foil/paper, and methods of preparing such flexible composites. In a second embodiment, there is a thermal management system comprising at least one flexible composites as set forth just Supra, wherein a graphite surface of a flexible composite is in thermal contact with a heat source of a heat generating device.
1 . A flexible composite of graphite leaf, containing non-natural graphite fillers selected from the group consisting essentially of: fibers, fibrils, powders, particles, and, flakes.
2 . The flexible composite as claimed in claim 1 wherein said filler content is from 0.1 weight % to 80 weight %.
3 . The flexible composite as claimed in claim 1 wherein said filler content is from 0.5 weight % to 60 weight %.
4 . The flexible composite as claimed in claim 1 wherein said filler content is from 1 weight % to 40 weight %.
5 . The flexible composite as claimed in claim 1 wherein said filler content is from 2 weight % to 30 weight %.
6 . The flexible composite as claimed in claim 1 wherein said graphite is from a natural source.
7 . The flexible composite as claimed in claim 1 wherein said graphite is exfoliated.
8 . The flexible composite as claimed in claim 1 wherein said flexible composite is formed of compressed materials.
9 . The flexible composite as claimed in claim 1 wherein said composite is processable in various shapes.
10 . The flexible composite as claimed in claim 1 comprising natural graphite and filler materials which have in-plane thermal conductivity higher than 400 W/mK.
11 . The flexible composite as claimed in claim 10 with a thickness ranging from 5 um to 1000 um.
12 . The flexible composite as claimed in claim 10 with a thickness ranging from 10 um to 800 um.
13 . The flexible composite as claimed in claim 10 with a thickness ranging from 15 um to 600 um.
14 . The flexible composite as claimed in claim 10 with a thickness ranging from 20 um to 400 um.
15 . The flexible composite as claimed in claim 10 with a thickness ranging from 25 um to 300 um.
16 . The flexible composite as claimed in claim 1 wherein said graphite and said fillers are heterogeneous across the width of said composite.
17 . The flexible composite as claimed in claim 1 wherein one side of said composite has more graphite and said opposite side has more filler than said one side.
18 . The flexible composite as claimed in claim 1 wherein said graphite is predominantly one side of the thickness of the leaf, the filler material is predominantly on the opposite side and the graphite and filler are interpenetrating.
19 . The flexible composite as claimed in claim 1 wherein said composite consists of a graphite rich layer with more than 80% of graphite and a filler rich layer with more than 80% of filler material.
20 . The flexible composite as claimed in claim 1 wherein said composite consists of a layer in which the ratio of graphite and filler material changes throughout the thickness direction.
21 . The flexible composite as claimed in claim 1 wherein the thermal conductivity in through-plane direction is higher than a 100% graphite composite.
22 . A thermal management system comprising a flexible composite of claim 1 , wherein said graphite surface of said flexible composite is in thermal contact with a heat source from a heat generating device.
23 . The thermal management system as claimed in claim 22 in combination with a portable electronic device.
24 . The thermal management system as claimed in claim 22 in combination with an LED device.
25 . The thermal management system as claimed in claim 22 in combination with an industrial device.
26 . The thermal management system as claimed in claim 22 in combination with a medical device.
27 . The thermal management system as claimed in claim 22 in combination with a military device.
28 . The thermal management system as claimed in claim 22 in combination with a device for aerospace vehicles.
29 . The thermal management system as claimed in claim 22 in combination with a device for automotive vehicles.
30 . The thermal management system as claimed in claim 22 in combination with a device for train systems.
31 . The flexible composite as claimed in claim 1 comprising two natural graphite layers and filler materials wherein said filler surfaces are in thermal contact with two thermal sources.
32 . The thermal management system as claimed in claim 22 comprising said flexible composite wherein said two graphite surfaces are in thermal contact with two thermal sources.
33 . The thermal management system as claimed in claim 32 wherein said thermal sources are batteries.
34 . The flexible composite as claimed in claim 1 wherein said flexible composite is formed by compressing graphite and at least one filler material.
35 . The flexible composite as claimed in claim 1 wherein said graphite is exfoliated.
36 . The flexible composite as claimed in claim 1 wherein said materials are deposited from slurry and then compressed.
37 . The flexible composite as claimed in claim 36 wherein said slurry is partially segregated to form a heterogeneous composite.