1098 results about "Graphene flake" patented technology

The present invention provides a nano-scaled graphene platelet-based composite material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and (b) a plurality of nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm; wherein at least one of the particles or coating is physically attached or chemically bonded to at least one of the graphene platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating in the range of 98% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, an excellent reversible capacity, and a long cycle life.

The present invention provides a nano-scaled graphene platelet-based composite material composition for use as an electrode, particularly as an anode of a lithium ion battery. The composition comprises: (a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and (b) a plurality of nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm; wherein at least one of the particles or coating is physically attached or chemically bonded to at least one of the graphene platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating in the range of 98% to 10% by weight. Also provided is a lithium secondary battery comprising such a negative electrode (anode). The battery exhibits an exceptional specific capacity, an excellent reversible capacity, and a long cycle life.

Disclosed is an electrode for an electrochemical energy storage device, the electrode comprising a self-supporting layer of a mixture of graphene sheets and spacer particles and / or binder particles, wherein the electrode is prepared without using water, solvent, or liquid chemical. The graphene electrode prepared by the solvent-free process exhibits many desirable features and advantages as compared to the corresponding electrode prepared by a known wet process. These advantages include a higher electrode specific surface area, higher energy storage capacity, improved or higher packing density or tap density, lower amount of binder required, lower internal electrode resistance, more consistent and uniform dispersion of graphene sheets and binder, reduction or elimination of undesirable effect of electrolyte oxidation or decomposition due to the presence of water, solvent, or chemical, etc.

Provided is a simple, fast, scalable, and environmentally benign method of producing a graphene-reinforced inorganic matrix composite directly from a graphitic material, the method comprising: (a) mixing multiple particles of a graphitic material and multiple particles of an inorganic solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of solid inorganic carrier material particles to produce graphene coated or graphene-embedded inorganic particles inside the impacting chamber; and (c) forming graphene-coated or graphene-embedded inorganic particles into the graphene-reinforced inorganic matrix composite. Also provided is a mass of the graphene-coated or graphene-embedded inorganic particles produced by this method.

Nano-composites include a graphite material such as nanotubes or graphene sheets and a partial or complete coating of a polymer including sufficient π-conjugated moieties to interact with surfaces of the graphite material. The polymers may also include electropolymerizable or oxidatively polymerizable moieties so the films may be crosslinked. The films may be used to form layers on substrates or patterned layers on substrates.

A transparent and conductive film comprising at least one network of graphene flakes is described herein. This film may further comprise an interpenetrating network of other nanostructures, a polymer and / or a functionalization agent(s).

Provided is an integral 3D graphene-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1 / 100 to 1 / 2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d002 from 0.3354 nm to 0.40 nm and the graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.01% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof. Also provided are a process for producing the hybrid form, products containing the hybrid foam, and its applications.

The present invention relates to a method for preparing a graphene reinforced metal-based composite material through discharge plasma (SPS) sintering. The method is characterized in that the graphene reinforced metal-based block material is prepared through SPS sintering and has the following advantages that: the preparation method is simple, the material is compact and does not have pores, the graphene mass fraction can be arbitrarily regulated, the distribution is uniform, no aggregation is generated, the material mechanical property isotropy is provided, and the wettability of the metal and the graphene interface is good. The method comprises: (1) reducing graphene oxide through a chemical method or a hydrothermal method to obtain graphene sheets with a sheet layer thickness of not more than 4 nm and sheet layer diameter of not more than 50 [mu]m; and (2) preparing metal powder with a particle size of not more than 200 [mu]m through a rotating electrode atomization method, mechanical crushing or a high-speed ball milling method; (3) carrying out mechanical or ball milling mixing on the graphene powder and the metal powder according to the required mass ratio; and (4) carrying out SPS sintering forming on the mixed powder, wherein the obtained material has characteristics of improved mechanical property, decreased density, good heat conduction capability, and good electric conduction capability, and the performance customizing can be achieved by adjusting the preparation parameters.

The invention discloses graphene composite conductive slurry as well as a preparation method and application thereof. The graphene composite conductive slurry comprises graphene, a non-flaky conducting agent, a dispersing agent, a solvent and a viscosity regulator; the non-flaky conducting agent is at least partially embedded between graphene flakes. The preparation method comprises the followingsteps: mixing expanded graphite, the dispersing agent and the solvent uniformly and performing shear stripping to prepare first slurry; adding the non-flaky conducting agent into the first slurry, andperforming partial intercalation treatment at least through a grinding mode to disperse the non-flaky conducting agent and the graphene flakes uniformly to prepare second slurry. The graphene composite conductive slurry has excellent dispersing stability, enables an active material to show up excellent electrochemical property when being in a lithium ion battery, and can improve the electrode capacity, reduce the internal resistance of the battery and improve cycling performance; meanwhile, the preparation method has the advantages of simple process, high operability, wide raw material source, low cost and the like.

A process for producing a highly conducting film of conductor-bonded graphene sheets that are highly oriented, comprising: (a) preparing a graphene dispersion or graphene oxide (GO) gel; (b) depositing the dispersion or gel onto a supporting solid substrate under a shear stress to form a wet layer; (c) drying the wet layer to form a dried layer having oriented graphene sheets or GO molecules with an inter-planar spacing d002 of 0.4 nm to 1.2 nm; (d) heat treating the dried layer at a temperature from 55° C. to 3,200° C. for a desired length of time to produce a porous graphitic film having pores and constituent graphene sheets or a 3D network of graphene pore walls having an inter-planar spacing d002 less than 0.4 nm; and (e) impregnating the porous graphitic film with a conductor material that bonds the constituent graphene sheets or graphene pore walls to form the conducting film.