Preparation method of high-performance graphene fiber and graphene fiber

The invention discloses a preparation method of a high-performance graphene fiber and the graphene fiber. The preparation method comprises the following steps: (1) preparing a spinning solution, namely preparing and preparing a graphene oxide solution with the concentration of 5-15g/L, and adjusting the pH value to 5-12 to obtain the spinning solution; (2) preparation of graphene oxide fibers: injecting the spinning solution into a coagulating bath at the speed of 0.1-1mL/min through a 0.2-1mm spinning nozzle, and drying to obtain the graphene oxide fibers; (3) low-temperature stretching and pre-reduction: placing the graphene oxide fiber in an atmosphere furnace, applying a tensile force to the fiber, and carrying out heating and pre-reduction at a pre-reduction temperature of 150-500 DEG C to obtain a pre-reduced graphene oxide fiber; and (4) high-temperature reduction: putting the pre-reduced graphene oxide fiber into an atmosphere furnace at the high-temperature reduction temperature of 600-1800 DEG C, in