▎ 摘　　要

NOVELTY - A composite powder includes graphene and silicon dioxide microsphere, where the graphene and silicon dioxide microspheres are combined through chemical bond, the average transverse size of the graphene is 5-30 μm, and the particle size of the silicon dioxide microsphere is 0.5-20 μm. USE - Composite powder used for heat dissipation coating (claimed). ADVANTAGE - The silica microspheres cannot only improve heat resistance of the coating, but also hinder agglomeration of graphene and improve dispersibility of graphene in the coating, and can also change orientation distribution of graphene in the coating and increase orientation ratio perpendicular to substrate direction, so that coating has both excellent lateral and longitudinal thermal conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation of the composite powder, which involves: (a) modifying graphene surface, so that graphene surface has at least one of organic groups, such as hydroxyl, carboxyl, epoxy, acyl and amino groups to obtain modified graphene; and (b) selecting silica microspheres whose surface is modified with at least one organic group in hydroxyl and carboxyl groups, and reacting organic groups on surface of the modified graphene and organic groups on surface of the silica microspheres to combine graphene and silica microspheres through chemical bonds; and (2) application of the composite powder in heat dissipation coating, which involves: (a) providing heat-dissipating coating through the composite powder, and forming the heat-dissipating coating into heat dissipation coating.