Nanotek Instruments, Inc.

Global Graphene Group, Inc.

Wei Xiong

Bor Z Jang

Aruna Zhamu

Mingchao Wang

Yanbo Wang

Hui He

Yi-jun Lin

Guorong Chen

Qing Fang

Lin Yi-jun

A graphene oxide-coated graphitic foil, composed of a graphitic substrate or core layer having two opposed primary surfaces and at least a graphene oxide coating layer deposited on at least one of the two primary surfaces, wherein the graphitic substrate layer has a thickness preferably from 0.34 nm to 1 mm, and the graphene oxide coating layer has a thickness preferably from 0.5 nm to 1 mm and an oxygen content of 0.01%-40% by weight based on the total graphene oxide weight. The graphitic substrate layer may be preferably selected from flexible graphite foil, graphene film, graphene paper, graphite particle paper, carbon-carbon composite film, carbon nanofiber paper, or carbon nanotube paper. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface smoothness, surface hardness, and scratch resistance unmatched by any thin-film material of comparable thickness range.

Graphene oxide-coated graphitic foil and processes for producing same

A rechargeable lithium-sulfur cell comprising a cathode, an anode, a separator electronically separating the two electrodes, a first electrolyte in contact with the cathode, and a second electrolyte in contact with the anode, wherein the first electrolyte contains a first concentration, C, of a first lithium salt dissolved in a first solvent when the first electrolyte is brought in contact with the cathode, and the second electrolyte contains a second concentration, C, of a second lithium salt dissolved in a second solvent when the second electrolyte is brought in contact with the anode, wherein Cis less than C. The cell exhibits an exceptionally high specific energy and a long cycle life.

Lithium-sulfur secondary battery containing gradient electrolyte

A unitary graphene-based integrated heat sink comprising a heat collection member (base) and at least one heat dissipation member (e.g. fins) integral to the baser, wherein the base is configured to be in thermal contact with a heat source, collects heat therefrom, and dissipates heat through the fins. The unitary graphene material is obtained from heat-treating a graphene oxide gel at a temperature higher than 100&#xb0; C., 500&#xb0; C., 1,250&#xb0; C., or 2,000&#xb0; C., and contains chemically bonded graphene molecules having inter-graphene distance of 0.3354-0.4 nm (preferably &#x3c;0.337 nm). The unitary graphene material is a graphene single crystal, a poly-crystal with incomplete grain boundaries, or a poly-crystal having large grain sizes (e.g. &#x3e;mm or cm), exhibiting a degree of graphitization preferably from 1% to 100% and a Mosaic spread value less than 0.7 (preferably no greater than 0.4). The finned heat sink may also be made from a filler-reinforced graphene matrix composite.

Unitary graphene-based composite material

This invention provides an inorganic coating-protected unitary graphene material article for concentrated photovoltaic cell heat dissipation. The article comprises at least a layer of unitary graphene material having two primary surfaces and an electrically non-conducting layer of inorganic coating deposited on at least one of the primary surfaces, wherein the unitary graphene material is obtained from heat-treating a graphene oxide gel at a heat treatment temperature higher than 100&#xb0; C. and contains chemically bonded graphene molecules or chemically merged graphene planes having an inter-graphene spacing no greater than 0.40 nm, preferably less than 0.337 nm, and most preferably less than 0.3346 nm.

Inorganic coating-protected unitary graphene material for concentrated photovoltaic applications

A heat dissipation system, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the device; (b) a heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface. The heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate/core layer with at least one primary surface coated with a graphene oxide coating layer. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance, making this the most effective heat dissipation system.

Thermal management system containing a graphene oxide-coated graphitic foil laminate for electronic device application

A unitary graphene layer or graphene single crystal containing closely packed and chemically bonded parallel graphene planes having an inter-graphene plane spacing of 0.335 to 0.40 nm and an oxygen content of 0.01% to 10% by weight, which unitary graphene layer or graphene single crystal is obtained from heat-treating a graphene oxide gel at a temperature higher than 100&#xb0; C., wherein the average mis-orientation angle between two graphene planes is less than 10 degrees, more typically less than 5 degrees. The molecules in the graphene oxide gel, upon drying and heat-treating, are chemically interconnected and integrated into a unitary graphene entity containing no discrete graphite flake or graphene platelet. This graphene monolith exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface smoothness, surface hardness, and scratch resistance unmatched by any thin-film material of comparable thickness range.

Heat dissipation system comprising a unitary graphene monolith

A graphene oxide-coated graphitic foil, composed of a graphitic substrate or core layer having two opposed primary surfaces and at least a graphene oxide coating layer deposited on at least one of the two primary surfaces, wherein the graphitic substrate layer has a thickness preferably from 0.34 nm to 1 mm, and the graphene oxide coating layer has a thickness preferably from 0.5 nm to 1 mm and an oxygen content of 0.01%-40% by weight based on the total graphene oxide weight. The graphitic substrate layer may be preferably selected from flexible graphite foil, graphene film, graphene paper, graphite particle paper, carbon-carbon composite film, carbon nano-fiber paper, or carbon nano-tube paper. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface smoothness, surface hardness, and scratch resistance unmatched by any thin-film material of comparable thickness range.

Process for unitary graphene layer or graphene single crystal

Unitary graphene material-based integrated finned heat sink

Disclosed is a graphene composite thin film composition composed of nano graphene platelets (NGPs) bonded by a graphene oxide binder, wherein the NGPs contain single-layer graphene or multi-layer graphene sheets having a thickness from 0.335 nm to 100 nm. The NGPs occupy a weight fraction of 1% to 99.9% of the total composite weight. The graphene oxide binder, having an oxygen content of 1-40% (preferably &#x3c;10%) by weight based on the total graphene oxide weight, is obtained from a graphene oxide gel. The composite forms a thin film with a thickness no greater than 1 mm, but preferably no greater than 100 &#x3bc;m and no less than 10 &#x3bc;m. This composition has a combination of exceptional thermal conductivity, electrical conductivity, and mechanical strength unmatched by any thin-film material of comparable thickness range.

Graphene oxide gel bonded graphene composite films and processes for producing same

Unitary graphene layer or graphene single crystal

Disclosed is an integrated graphene film-enhanced display device, comprising: (a) a display device which comprises one or multiple heat sources and a back surface where a localized area is at a higher temperature than an adjacent area; and (b) a heat spreader which comprises at least one sheet of integrated graphene film having two major surfaces, wherein one of the major surfaces of the heat spreader is in thermal contact with one or multiple heat sources and further wherein the heat spreader itself reduces the temperature difference between locations on the display device. The integrated graphene film, either a graphene film obtained from a graphene oxide gel or a graphene composite film formed of graphene oxide gel-bonded nano graphene platelets (NGPs), exhibits highest thermal conductivity and highest effectiveness in reducing hot spots in various kinds of display devices.

Integrated graphene film heat spreader for display devices

Disclosed is a graphene-based heat dissipation system for an electronic device, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the electronic device; (b) a heat-conducting layer comprising two major surfaces, the heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface of the electronic device; wherein the heat-conducting layer comprises at least one sheet of integrated graphene film which thermally shields the second component or the external surface of the electronic device from heat generated by the heat source.

Thermal management system containing an integrated graphene film for electronic devices

A unitary graphene matrix composite comprising: (a) a unitary graphene matrix containing an oxygen content of 0.001% to 10% by weight, obtained from heat-treating a graphene oxide gel at a temperature higher than 100&#xb0; C. and contains no discrete graphene platelets derived from the graphene oxide gel; (b) a carbon or graphite filler phase selected from carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof. The carbon or graphite filler phase is preferably in a particulate, filamentary, or rod-like form dispersed in and bonded by the unitary graphene matrix. This composite exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance.

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Dayton, OH, United States of America

Wei Xiong