A method of producing graphene including the following steps is provided. A graphite material is dispersed in a solution to form a graphite suspension solution. A first crushing process and a second crushing process are performed on the graphite suspension solution sequentially to crush the graphite material, so as to form the graphene. The first crushing process includes applying a first pressure to the graphite suspension solution, and the second crushing process includes applying a second pressure to the graphite suspension solution. The second pressure is greater than the first pressure.

Provided are methods for forming graphene or functionalized graphene thin films. Also provided are graphene and functionalized graphene thin films formed by the methods. For example, electrophoretic deposition methods and stamping methods are used. Defect-free thin films can be formed. Patterned films can be formed. The methods can provide conformal coatings on non-planar substrates.

Provided are nanocrystalline graphene and a method of forming the nanocrystalline graphene through a plasma enhanced chemical vapor deposition process. The nanocrystalline graphene may have a ratio of carbon having an sp.sup.2 bonding structure to total carbon within the range of about 50% to 99%. In addition, the nanocrystalline graphene may include crystals having a size of about 0.5 nm to about 100 nm.

A graphene powder, its preparation method and application are provided. The graphene powder is a stack of graphene sheets. The graphene powder involves in its Raman spectrum a D peak and a G peak with peak heights of I.sub.D and I.sub.G respectively, where I.sub.D/I.sub.G is 0.10 or less. The graphene powder can be applied in conductive composite materials, anti-corrosion coatings, heat dissipation composite materials. In particular, when used in lithium-ion batteries, it can significantly reduce electrode internal resistance and improve battery stability at any current rates.

Disclosed herein is a method of converting a carbon material to graphene, the method comprising the step of subjecting an amorphous carbon material pellet submerged in a molten inorganic material that comprises an alkaline earth halide to an electrochemical reaction in an inert atmosphere for a period of time, wherein the amorphous carbon material pellet is converted to a graphene pellet comprising graphene flakes by said reaction.

A method for producing a carbon nanostructure aggregate having a large external specific surface area and a carbon nanostructure aggregate are provided. The method for producing a carbon nanostructure aggregate comprises supplying a source gas to a catalyst to grow a carbon nanostructure aggregate comprising a plurality of carbon nanostructures by a chemical vapor deposition method, wherein a gas derived from the source gas and brought into contact with the catalyst comprises: as a hydrocarbon to serve as a carbon source, at least one of: a hydrocarbon A having at least one acetylene skeleton, a hydrocarbon B having at least one 1,3 -butadiene skeleton, a hydrocarbon C having at least one cyclopentadiene skeleton, and a hydrocarbon D having at least one allene skeleton, and carbon monoxide and carbon dioxide; and satisfies 0.01[CO]/[C]15 where [C] is a total volume concentration of carbon contained in the hydrocarbons A, B, C, and D, and [CO] is a volume concentration of carbon monoxide.

A graphene dispersion liquid containing graphene dispersed in a dispersion medium is described, in which, in the graphene contained in the dispersion liquid, a proportion of graphene with a size in the plane direction of 500 nm or more and 1 ?m or less is 30% or more on an area basis, and a proportion of graphene with a size in the plane direction of 10 ?m or more and 50 ?m or less is 30% or more on an area basis. The graphene dispersion liquid is in a stable dispersion state and forms a strong conductive path.

The present invention relates to preparation of a highly dispersible graphene powder. Further, the present invention includes providing an electrode for a lithium ion battery having good output characteristics and cycle characteristics by utilizing a highly dispersible graphene powder. The present invention also includes providing a graphene powder having a specific surface area of 80 m.sup.2/g or more to 250 m.sup.2/g or less as measured by BET measurement, and an oxygen-to-carbon element ratio of 0.09 or more to 0.30 or less as measured by X-ray photoelectron spectroscopy.

The present invention relates in part to a method of fabricating graphene structures from graphene oxide by reducing the graphene oxide on a patterned substrate. The invention also relates in part to graphene structures produced using said method and electrodes and capacitors comprising said graphene structures.

Provided herein are graphene nanoribbons with high structural uniformity and low levels of impurities and methods of synthesis thereof. Also provided herein are graphene nanoplatelets of superior structural uniformity and low levels of impurities and methods of synthesis thereof. Further provided herein are mixtures of graphene nanoribbons and graphene nanoplatelets of good structural uniformity and low levels of impurities and methods of synthesis thereof. The method includes, for example, the steps of depositing catalyst on a constantly moving substrate, forming carbon nanotubes on the substrate, separating carbon nanotubes from the substrate, collecting the carbon nanotubes from the surface where the substrate moves continuously and sequentially through the depositing, forming, separating and collecting steps. Further processing steps convert the synthesized carbon nanotubes to graphene nanoribbons, graphene nanoplatelets and mixtures thereof.