▎ 摘　　要

Graphene fibers have great potential in yarn supercapacitors (YSCs) because of their good strength, flexibility, electrical conductivity, and ultrahigh specific surface area. Among the reported results, graphene fibers show higher capacitance properties, but their mechanical strength is relatively low. Here, we design a simple method to prepare high-performance graphene fibers with high strength and high capacitance by adding carboxymethyl cellulose (CMC) to graphene oxide (GO). The hydrogen bonding network between GO and CMC greatly improves the strength of the fiber. CMC can greatly improve the hydrophilicity of the graphene fiber, reduce the stacking of graphene sheets, increase the effective active area, and thus increase the capacitance. The as-prepared rGO-CMC fiber shows a high strength of 526.4 MPa, and the capacitance of YSCs reaches 197.7 mF/cm(2).