16121 results about "Graphene" patented technology

A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 μm. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life.

An economical method of preparing a large-sized graphene sheet having a desired thickness includes forming a film, the film comprising a graphitizing catalyst; heat-treating a gaseous carbon source in the presence of the graphitizing catalyst to form graphene; and cooling the graphene to form a graphene sheet. A graphene sheet prepared according to the disclosed method is also described.

A graphene layer is formed on a surface of a silicon carbide substrate. A dummy gate structure is formed over the fin, in the trench, or on a portion of the planar graphene layer to implant dopants into source and drain regions. The dummy gate structure is thereafter removed to provide an opening over the channel of the transistor. Threshold voltage adjustment implantation may be performed to form a threshold voltage implant region directly beneath the channel, which comprises the graphene layer. A gate dielectric is deposited over a channel portion of the graphene layer. After an optional spacer formation, a gate conductor is formed by deposition and planarization. The resulting graphene-based field effect transistor has a high carrier mobility due to the graphene layer in the channel, low contact resistance to the source and drain region, and optimized threshold voltage and leakage due to the threshold voltage implant region.

Disclosed is a hybrid fiber tow that comprises multiple continuous filaments and nanoscale fillers embedded in the interstitial spaces between continuous filaments. Nanoscale fillers may be selected from a nanoscale graphene plate, non-graphite platelet, carbon nano-tube, nano-rod, carbon nano-fiber, non-carbon nano-fiber, or a combination thereof. Also disclosed are a hybrid fiber tow impregnated with a matrix material and a composite structure fabricated from a hybrid fiber tow. The composite exhibits improved physical properties (e.g., thermal conductivity) in a direction transverse to the continuous fiber axis. A roll-to-roll process for producing a continuous fiber tow or matrix-impregnated fiber tow and an automated process for producing composite structures containing both continuous filaments and nanoscale fillers are also provided.

The present invention provides a lithium ion battery that exhibits a significantly improved specific capacity and much longer charge-discharge cycle life. In one preferred embodiment, the battery comprises an anode active material that has been prelithiated and pre-pulverized. This anode may be prepared with a method that comprises (a) providing an anode active material (preferably in the form of fine powder or thin film); (b) intercalating or absorbing a desired amount of lithium into the anode active material to produce a prelithiated anode active material; (c) comminuting the prelithiated anode active material into fine particles with an average size less than 10 μm (preferably <1 μm and most preferably <200 nm); and (d) combining multiple fine particles of the prelithiated anode active material with a conductive additive and/or a binder material to form the anode. Preferably, the prelithiated particles are protected by a lithium ion-conducting matrix or coating material. Further preferably, the matrix material is reinforced with nano graphene platelets.

A semiconductor device according to one embodiment includes: a semiconductor substrate; an insulating film provided on the semiconductor substrate and containing a wiring trench; a first catalyst layer provided directly or via another member on side and bottom surfaces of the wiring trench; and a first graphene layer provided in the wiring trench so as to be along the side and bottom surface of the wiring trench, the first graphene layer being provided on the first catalyst layer so as to be in contact with the first catalyst layer.

A lithium-ion cell comprising: (A) a cathode comprising graphene as the cathode active material having a surface area to capture and store lithium thereon and wherein said graphene cathode is meso-porous having a specific surface area greater than 100 m²/g; (B) an anode comprising an anode active material for inserting and extracting lithium, wherein the anode active material is mixed with a conductive additive and/or a resin binder to form a porous electrode structure, or coated onto a current collector in a coating or thin film form; (C) a porous separator disposed between the anode and the cathode; (D) a lithium-containing electrolyte in physical contact with the two electrodes; and (E) a lithium source disposed in at least one of the two electrodes when the cell is made. This new Li-ion cell exhibits an unprecedentedly high energy density.

An electronic device comprises a body including a single crystal region on a major surface of the body. The single crystal region has a hexagonal crystal lattice that is substantially lattice-matched to graphene, and a at least one epitaxial layer of graphene is disposed on the single crystal region. In a currently preferred embodiment, the single crystal region comprises multilayered hexagonal BN. A method of making such an electronic device comprises the steps of: (a) providing a body including a single crystal region on a major surface of the body. The single crystal region has a hexagonal crystal lattice that is substantially lattice-matched to graphene, and (b) epitaxially forming a at least one graphene layer on that region. In a currently preferred embodiment, step (a) further includes the steps of (a1) providing a single crystal substrate of graphite and (a2) epitaxially forming multilayered single crystal hexagonal BN on the substrate. The hexagonal BN layer has a surface region substantially lattice-matched to graphene, and step (b) includes epitaxially forming at least one graphene layer on the surface region of the hexagonal BN layer. Applications to FETs are described.

Exemplary embodiment can utilize the properties of tunable thin-film, material (e.g., graphene) to efficiently modulate the intensity, phase, and/or polarization of transmitted and/or reflected radiation, including mid-infrared (“mid-IR”) radiation. Exemplary embodiments include planar antennas comprising tunable thin-film material sections and metallic sections disposed in contact with the tunable thin-film material sections, each metallic section having a gap with at least one dimension related to a wavelength of the radiation, which in some embodiments may be less than the wavelength. The metallic layer may comprise rods arrange in one or more shapes, or one or more apertures of one or more shapes. Embodiments of the antenna may also comprise a substrate, which may be a semiconductor or conductor in various embodiments. Embodiments also include systems, computer-implemented methods, devices, and computer-readable media for effectuating desired modulation of incident radiation by, e.g., varying the doping level of the tunable thin-film material.

Disclosed is a nano-scaled graphene article comprising a non-woven aggregate of nano-scaled graphene platelets wherein each of the platelets comprises a graphene sheet or multiple graphene sheets and the platelets have a thickness no greater than 100 nm (preferably smaller than 10 nm) and platelets contact other platelets to define a plurality of conductive pathways along the article. The article has an exceptional thermal conductivity (typically greater than 500 Wm⁻¹K⁻¹) and excellent electrical conductivity (typically greater than 1,000 S/cm). Thin-film articles of the present invention can be used for thermal management in micro-electronic devices and for current-dissipating on an aircraft skin against lightning strikes.

The invention relates to graphene conductive ink comprising the following components by weight percent: 0.01-25% of resin, 0.1-95% of graphene, 0.1-30.0% of assistant, and 5.0-99.79% of solvent. The two-dimensional conductive material graphene is used for the conductive ink; the graphene with special ratio is adopted as a conductive phase; the resin is taken as a binder; the assistant and the solvent are used for assisting; the prepared ink is good in anti-sedimentation property, and adjustable in viscosity and rheological behavior, and can be used for flexibly printing on the surfaces of a plurality of substrates; and the ink is stable in mechanical property, stable in electrical properties, oxidation resistance, acid resistance, alkali resistance and resistance to a chemical solvent after being cured.

Disclosed herein is a reduced graphene oxide doped with a dopant, and a thin layer, a transparent electrode, a display device and a solar cell including the reduced graphene oxide. The reduced graphene oxide doped with a dopant includes an organic dopant and/or an inorganic dopant.

Carbon nanostructures are mass produced from graphite. In particularly preferred aspects, graphene is thermo-chemically derived from graphite and used in numerous compositions. In further preferred aspects, the graphene is re-shaped to form other nanostructures, including nanofractals, optionally branched open-ended SWNT, nanoloops, and nanoonions.

Device are described that include a semiconductor material layer and at least one graphene-based electrode disposed over a portion of the semiconductor material layer, such that the at least one graphene-based electrode forms an overlap region with the semiconductor material layer. The device includes a means for providing charge carriers in the at least one graphene-based electrode proximate to the overlap region, to reduce a difference between a work function of the at least one graphene-based electrode and an electron affinity of the semiconductor material layer, to reduce a Schottky barrier height between the semiconductor material layer and the at least one graphene-based electrode.

Embodiments of the present invention provide methods for fabricating graphene nanoelectronic devices with semiconductor compatible processes, which allow wafer scale fabrication of graphene nanoelectronic devices. Embodiments of the present invention also provide methods for passivating graphene nanoelectronic devices, which enable stacking of multiple graphene devices and the creation of high density graphene based circuits. Other embodiments provide methods for producing devices with graphene layer segments having multiple thicknesses.

Multilayer coatings comprising at least two layers wherein at least one layer comprises a composition comprising graphene sheets and at least one binder and wherein at least two layers have different compositions.

An electrochemical device comprising a chemically modified graphene material is disclosed. An ultracapacitor comprising a chemically modified graphene material is disclosed, along either with a method of making an ultracapacitor, the method comprising forming two electrodes, wherein at least one of the two electrodes comprises a graphene material, and positioning each of the two electrodes such that each is in contact with an opposing side of a separator and a current collector

Provided are a graphene sheet and a process of preparing the same. Particularly, a process of economically preparing a large-area graphene sheet having a desired thickness and a graphene sheet prepared by the process are provided.

Nanocomposite materials having at least two layers, each layer consisting of one metal oxide bonded to at least one graphene layer were developed. The nanocomposite materials will typically have many alternating layers of metal oxides and graphene layers, bonded in a sandwich type construction and will be incorporated into an electrochemical or energy storage device.

A zinc ion-exchanging battery device comprising: (A) a cathode comprising two cathode active materials (a zinc ion intercalation compound and a surface-mediating material); (B) an anode containing zinc metal or zinc alloy; (C) a porous separator disposed between the cathode and the anode; and (D) an electrolyte containing zinc ions that are exchanged between the cathode and the anode during battery charge/discharge. The zinc ion intercalation compound is selected from chemically treated carbon or graphite material having an expanded inter-graphene spacing d₀₀₂ of at least 0.5 nm, or an oxide, carbide, dichalcogenide, trichalcogenide, sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, vanadium, chromium, cobalt, manganese, iron, nickel, or a combination thereof. The surface-mediating material contains exfoliated graphite or multiple single-layer sheets or multi-layer platelets of a graphene material.

Provided is a field effect transistor including a graphene channel layer, and capable of increasing an on/off ratio of an operating current by using the graphene of the graphene channel layer. The field effect transistor includes: a substrate; the graphene channel layer which is disposed on a portion of the substrate and includes graphene; a first electrode disposed on a first region of the graphene channel layer and a portion of the substrate; an interlayer disposed on a second region of the graphene channel layer, which is apart from the first region, and a portion of the substrate; a second electrode disposed on the interlayer; a gate insulation layer disposed on a portion of the graphene channel layer, the first electrode, and the second electrode; and a gate electrode disposed on a portion of the gate insulation layer.

The present invention relates to a method for forming a graphene protective film having gas and moisture barrier properties, to a graphene protective film formed by the method, and to the use thereof. A single-layer or multi-layer graphene protective film can be used as a material for a barrier coating or bags, and improves the gas and moisture barrier properties of a variety of devices in a wide array of industrial fields to thereby maintain the electrical characteristics of devices over a long period of time.

A method of fabricating graphene transistors, comprising providing an SOI substrate, performing an optional threshold implant on the SOI substrate, forming an upper silicon layer mesa island, carbonizing the silicon layer into SiC utilizing a gaseous source, converting the SiC into graphene, forming source/drain regions on opposite longitudinal ends of the graphene, forming gate oxide between the source/drain regions on the graphene, forming gate material over the gate oxide, creating a transistor edge, depositing dielectric onto the transistor edge and performing back end processing.

A method for producing isolatable and dispersible graphene sheets, wherein the graphene sheets may be tailored to be soluble in aqueous, non-aqueous or semi-aqueous solutions. The water soluble graphene sheets may be used to produce a metal nanoparticle-graphene composite having a specific surface area that is 20 times greater than aggregated graphene sheets. Graphene sheets that are soluble in organic solvents may be used to make graphene-polymer composites.

Compositions comprising at least one polymer binder, graphene sheets, and graphite, wherein the ratio by weight of graphite to graphene sheets is from about 40:60 to about 98:2.

Provided is a simple, fast, scalable, and environmentally benign method of producing graphene-embraced or encapsulated particles of a battery electrode active material directly from a graphitic material, the method comprising: a) mixing graphitic material particles and multiple particles of a solid electrode active material to form a mixture in an impacting chamber of an energy impacting apparatus, wherein the graphitic material has never been intercalated, oxidized, or exfoliated and the chamber contains therein no previously produced graphene sheets and no ball-milling media; b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for transferring graphene sheets from the graphitic material to surfaces of electrode active material particles to produce graphene-embraced electrode active material particles; and c) recovering the particles from the impacting chamber. Also provided is a mass of the graphene-embraced particles, electrode containing such particles, and battery containing this electrode.

A method of producing nano-scaled graphene platelets (NGPs) having an average thickness no greater than 50 nm, typically less than 2 nm, and, in many cases, no greater than 1 nm. The method comprises (a) intercalating a supply of meso-carbon microbeads (MCMBs) to produce intercalated MCMBs; and (b) exfoliating the intercalated MCMBs at a temperature and a pressure for a sufficient period of time to produce the desired NGPs. Optionally, the exfoliated product may be subjected to a mechanical shearing treatment, such as air milling, air jet milling, ball milling, pressurized fluid milling, rotating-blade grinding, or ultrasonicating. The NGPs are excellent reinforcement fillers for a range of matrix materials to produce nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.

A construction is provided for a finned heat sink constructed from a plurality of components separately formed from graphite materials. The components include a base and a plurality of fins. In one embodiment, the base is constructed from a first graphite material, and a plurality of elongated fins are constructed from a second graphite material, which may be the same material as the first graphite material. The fins each extend at least partially into the base, and have a length extending away from the base parallel to each other. The graphite material of the fins includes graphene layers aligned in planes parallel to the length of the fins. Two constructions are provided for the base. In one construction the base includes graphene layers aligned in planes parallel to the length of the fins. In another construction the base includes graphene layers aligned in planes perpendicular to the length of the fins.

Fibers described herein comprise a composition including a polymer and graphene sheets. The fibers can be further formed into yarns, cords, and fabrics. The fibers can be in the form of polyamide, polyester, acrylic, acetate, modacrylic, spandex, lyocell fibers, and the like. Such fibers can take on a variety of forms, including, staple fibers, spun fibers, monofilaments, multifilaments, and the like.

A method for making sulfur-graphene composite material is disclosed. In the method, a dispersed solution including a solvent and a plurality of graphene sheets dispersed in the solvent is provided. A sulfur-source chemical compound is dissolved into the dispersed solution to form a mixture. A reactant, according to the sulfur-source chemical compound, is introduced to the mixture. Elemental sulfur is produced on a surface of the plurality of graphene sheets due to a redox reaction between the sulfur-source chemical compound and the reactant, to achieve the sulfur-graphene composite material. The sulfur-graphene composite material is separated from the solvent.