Abstract: 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 ID and IG respectively, where ID/IG 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.

Abstract: A conductive composite material of graphene contains graphene nano-sheets and conjugated copolymers. The conjugated copolymers has alkynyl groups and are in a linear structure and grafted to the graphene nano-sheets. The preparation of conductive composite material includes the steps of: pretreating the graphene nano-sheets with 4-bromobenzenediazonium tetrafluoroborate, and forming the conjugated copolymers in the presence of the pretreated graphene nano-sheets. The conductive composite material of graphene can be uniformly dispersed in an electrode slurry, reduce the internal resistance of an electrode, and improve the electrical conductivity of an electrode. At the same time, the flexible structure associated with the graphene nano-sheets can buffer the volume expansion of the silicon-containing negative materials during charge-discharge cycling. Such a composite material can be in a lithium-ion battery.

Abstract: 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 ID and IG respectively, where ID/IG 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.

Abstract: A conductive composite material of graphene contains graphene nano-sheets and conjugated copolymers. The conjugated copolymers has alkynyl groups and are in a linear structure and grafted to the graphene nano-sheets. The preparation of conductive composite material includes the steps of: pretreating the graphene nano-sheets with 4-bromobenzenediazonium tetrafluoroborate, and forming the conjugated copolymers in the presence of the pretreated graphene nano-sheets. The conductive composite material of graphene can be uniformly dispersed in an electrode slurry, reduce the internal resistance of an electrode, and improve the electrical conductivity of an electrode. At the same time, the flexible structure associated with the graphene nano-sheets can buffer the volume expansion of the silicon-containing negative materials during charge-discharge cycling. Such a composite material can be in a lithium-ion battery.