Effect of Tension and High-Temperature on structural evolution of Graphene Oxide Fibers of Electrical Conductivity

Graphene fibers should have excellent electrical conductivity for use in high-performance wires. The electrical conductivity of graphene oxide (GO) fibers can be controlled through reduction treatment. Herein, the electrical conductivity of GO fibers were successfully enhanced by controlling the tension and temperature during the reduction process. Moreover, the changes in the microstructures of the GO fibers were investigated at different temperatures and tensions. The thermally reduced GO (TRGO) fibers exhibited a conductivity of 570S/m when subjected to a thermal reduction treatment at 450 °C and 3MPa. The produced fibers can endure repeated bending for 1400 cycles, with an average resistance change of ±1%. Microstructural analysis demonstrates that the cross-sectional porosity decreased from 40.22% to 14.30% after applying tension. Thus, the proposed reduction method enables an effective control of the structure and properties of graphene fibers. This allows the graphene fibers reduced using the proposed method to be used in high-performance wires.