A positive electrode active material having a core/shell structure, which includes a sulfur-carbon composite containing thermally expanded-reduced graphene oxide, a carbon material as a core, and carbon nanotubes as a shell. A method for preparing a positive electrode active material having a core/shell structure for a lithium secondary battery, including the steps of thermally expanding graphene oxide by heat treatment at a temperature in a range of 300° C. to 500° C. to prepare a thermally-expanded graphene oxide. Then, reducing the thermally-expanded graphene oxide by heat treatment at a temperature in a range of 700° C. to 1200° C. to prepare a thermally expanded-reduced graphene oxide. Next, mixing the thermally expanded-reduced graphene oxide and sulfur to prepare a sulfur-carbon composite. Last, mixing the sulfur-carbon composite and carbon nanotubes to form carbon nanotubes on a surface of the sulfur-carbon composite.

Disclosed are a positive electrode for a lithium secondary battery which can improve battery performance by coating the modified bottom-up graphene oxide (SBGO) on the positive electrode active material, and thus preventing the leaching of lithium polysulfide, a manufacturing method thereof, and a lithium secondary battery comprising the positive electrode. The positive electrode for the lithium secondary battery includes a positive electrode active material; and bottom-up graphene oxides coated on a surface of the positive electrode active material, where the bottom-up graphene oxides are cross-linked with each other through a hydrocarbon compound containing a cationic functional group.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

The present application discloses paint based on a graphene nano container and a self-repairing coating as well as a preparation method and application thereof. The paint comprises a first component comprising 20˜40 parts by weight of epoxy resin; a second component comprising 0.1˜2 parts by weight of corrosion inhibitor-loaded graphene nano container, 1 part by weight of diluent, 30˜60 parts by weight of epoxy curing agent, 1 part by weight of defoaming agent and 1 part by weight of flatting agent, wherein the corrosion inhibitor-loaded graphene nano container comprises graphene grafted with cyclodextrin and the corrosion inhibitor reversely binding to the cyclodextrin. The paint of the present application is simple in preparation process, green and environmental friendly in raw material, low in price and available, and meanwhile the self-repairing coating formed thereof is excellent in protection performance.

The present invention relates to 2D-material based composite materials such as aerogels and particularly, although not exclusively, to deposition of nanoparticles on 2D-material based aerogels. Also described are methods for manufacturing such materials.

The present invention relates to 2D-material based composite materials such as aerogels and particularly, although not exclusively, to deposition of nanoparticles on 2D-material based aerogels. Also described are methods for manufacturing such materials.

The method for synthesizing graphene derivatives from asphaltene includes one or more steps that are based on thermal and/or chemical treatments. In the thermal treatment, asphaltene was carbonized in a rotating quartz-tube furnace under an inert atmosphere (N.sub.2). This carbonization process was performed at a temperature range of 400-950° C. The carbonization process converted asphaltene molecules into graphene derivatives by eliminating the alkyl side chains, exfoliating the aromatic layers (n), and expanding the aromatic sheet diameter (L.sub.a). The chemical treatment, on the other hand, was performed on the asphaltene (i.e., graphene precursor) by dispersing the asphaltene molecules in a liquid intercalating agent to functionalize the asphaltene and expand the inter-layer distance between the aromatic sheets (intercalation). In this intercalation process, the graphitic surface of asphaltene is oxidized to form asphaltene oxide, and then graphene oxide (GO), which is a nonconductive hydrophilic carbon material.

A method of producing an electrochemically derived graphene oxide and product produced therefrom. The method comprises locating graphite particles within an electrochemical cell having a working electrode, counter electrode, and an aqueous acid electrolyte, the working electrode being positioned within the electrolyte to contact at least a portion of the graphite particles; agitating the graphite particles within the electrolyte; and applying a potential difference between the working electrode and counter electrode, thereby resulting in electrochemical exfoliation and oxidation of the graphite particles to produce graphene oxide.

A method of producing an electrochemically derived graphene oxide and product produced therefrom. The method comprises locating graphite particles within an electrochemical cell having a working electrode, counter electrode, and an aqueous acid electrolyte, the working electrode being positioned within the electrolyte to contact at least a portion of the graphite particles; agitating the graphite particles within the electrolyte; and applying a potential difference between the working electrode and counter electrode, thereby resulting in electrochemical exfoliation and oxidation of the graphite particles to produce graphene oxide.