▎ 摘　　要

NOVELTY - The preparation method of graphene reinforced carbon nanotube composite fiber involves: uniformly mixing expanded graphite and super acid serving as a dispersion solvent to form a graphene/super acid solution, where the super acid is chlorosulfonic acid; soaking carbon nanotube fibers in the graphene/super strong acid solution, and expanding the carbon nanotube fibers under the protonation action of a chlorosulfonic acid solvent to enable the graphene/super strong acid solution to enter the carbon nanotube fibers to form a uniform composite structure; and soaking the composite structure in a coagulating bath, dissolving the super acid, and realizing the precipitation of the graphene and the contraction of the carbon nanotube fiber to obtain the uniformly-compounded defect-free graphene-reinforced carbon nanotube composite fiber. USE - Preparation method of graphene reinforced carbon nanotube composite fiber. ADVANTAGE - The method realizes the introduction of the defect-free graphene in the gaps of the carbon nanotube fibers in the preparation process, can effectively reduce the interfacial resistance between the tubes, simultaneously improves the load transfer efficiency between the tubes, and realizes the continuous enhancement of the mechanical and electrical properties of the carbon nanotube fibers. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a device for producing the graphene-reinforced carbon nanotube composite fibers DESCRIPTION OF DRAWING(S) - The drawing shows a comparison graph of conductivity of the graphene-reinforced carbon nanotube composite fiber and the carbon nanotube original fiber. (Drawing includes non-English language text).