The present invention provides a method for preparation of sulfur functionalized graphene which contains the following steps: a) providing a dispersion of fluorinated graphite; b) subjecting the dispersion of fluorinated graphite to sonication and/or mechanical treatment and/or thermal treatment; c) preparing a metal polysulfide, starting from a metal sulfide and sulfur; d) contacting the product from step b) with the product of step c) at a temperature within the range of 10-110° C.; e) separating the solid product formed in step d) from the solution. Further provided are sulfur functionalized graphene with high sulfur loading obtained by this method, and its use in electrical cells.

The present disclosure provides a method of preparing graphene quantum dots by intercalation of graphite nanoparticles and continuous exfoliation in an aqueous solution. The preparation method has a short process time and uses graphite nanoparticles of several nm as a reactant. Thus, graphene quantum dots prepared by the preparation method are uniform in size and shape with minimized defects and improved electrical properties.

An air flow generating device, a graphene dispersion, and a preparation method thereof are provided. The graphene dispersion is formed by a graphene powder and a processing solvent, wherein the graphene in the graphene dispersion has an average diameter of 0.5 μm to 1 μm, 3 to 5 layers, a solid content of 5% to 50%, and a residue oxygen content less than 1 wt %, and after being left to stand for 12 hours, the graphene dispersion has a distribution concentration increasing from the top section to the bottom section of the storage container, a viscosity of 5000 cps to 8000 cps, and a graphene concentration of 20 wt %.

An air flow generating device, a graphene dispersion, and a preparation method thereof are provided. The graphene dispersion is formed by a graphene powder and a processing solvent, wherein the graphene in the graphene dispersion has an average diameter of 0.5 μm to 1 μm, 3 to 5 layers, a solid content of 5% to 50%, and a residue oxygen content less than 1 wt %, and after being left to stand for 12 hours, the graphene dispersion has a distribution concentration increasing from the top section to the bottom section of the storage container, a viscosity of 5000 cps to 8000 cps, and a graphene concentration of 20 wt %.

A thin plate-shaped graphite product is produced by applying a current to an electrochemical reaction system including a graphite-containing anode, a cathode optionally containing graphite, and an electrolyte solution containing tetrafluoroboric acid or hexafluorophosphoric acid as an electrolyte. Flaky graphite is produced by subjecting the thin plate-shaped graphite product to delamination.

A thin plate-shaped graphite product is produced by applying a current to an electrochemical reaction system including a graphite-containing anode, a cathode optionally containing graphite, and an electrolyte solution containing tetrafluoroboric acid or hexafluorophosphoric acid as an electrolyte. Flaky graphite is produced by subjecting the thin plate-shaped graphite product to delamination.

Provided is an face mask comprising: (a) a mask body configured to cover at least wearer's mouth and nose; and (b) a fastener to hold the mask in place on the wearer; wherein the mask body includes (i) an air-permeable outer layer preferably comprising a hydrophobic material (e.g. water-repelling fibers), (ii) an inner layer located on a wearer's side when the mask is worn, and (iii) a graphene foam layer disposed in the mask body between the outer layer and the inner layer or embedded (totally or partially) in the outer layer or the inner layer. The foam pore wall graphene surfaces may be deposited with an antiviral or anti-bacteria compound.

A preparation method a graphene dispersion is provided, including the following steps. First, a homogenization process is performed on a graphene powder and a processing solvent to form a graphene paste. Next, a layer-thinning process is performed on the graphene paste to form a graphene dispersion.

A preparation method a graphene dispersion is provided, including the following steps. First, a homogenization process is performed on a graphene powder and a processing solvent to form a graphene paste. Next, a layer-thinning process is performed on the graphene paste to form a graphene dispersion.

A composite cathode active material, a cathode including the composite cathode active material, and a lithium battery including the cathode are provided. The composite cathode active material includes a core including a lithium metal oxide and a coating layer on the core, wherein the lithium metal oxide includes two or more transition metals including nickel (Ni), an amount of Ni within one mole of the two or more transition metals included in the lithium metal oxide is about 0.65 mol or greater, the coating layer includes LiF, and a resistance of the composite cathode active material is lower than that of the core.