▎ 摘　　要

NOVELTY - Preparing graphene-modified high-strength and low-cost carbon fiber comprises the (i) adding polyacrylonitrile and tetraethylenepentamine into deionized water, refluxing at 105-115℃ for 3-5 hours, filtering the product, washing and drying to obtain amino-modified polyacrylonitrile, (ii) mixing graphene oxide, thionyl chloride and dimethylformamide, and refluxing and reacting at 70-80℃ for 18-24 hours to obtain acyl chloride graphene oxide, (iii) dissolving lignin and amino-modified polyacrylonitrile in a solvent, adding acyl chloride graphene oxide, and ultrasonically reacting for 30-60 minutes to obtain a spinning solution, spinning the spinning solution and forming primary fibers in a coagulation bath, drawing the primary fibers, washing, oiling, and drying to obtain carbon fiber precursors, and (iv) performing pre-oxidation and carbonization treatment on the obtained carbon fiber precursor to obtain the graphene-modified high-strength and low-cost carbon fiber. USE - The graphene-modified high-strength and low-cost carbon fiber is useful in tool products (claimed). ADVANTAGE - The method enables to prepare modified high-strength low-cost carbon fiber with high graphene and low cost, which is good for the application in the tool product, and effectively improves the carbon fiber strength, reduces the cost of the carbon fiber, and reduces the phase separation of lignin and polyacrylonitrile.