Controllable synthesis and electrochemical performance of hierarchically structured graphene fibers

The hierarchically structured graphene fibers were prepared by a facile chemical reduction and self-assembly strategy. SEM images of the as-prepared graphene fibers indicate the diameter is 130-150 μm, and a certain degree of graphene sheets orientation along the main axis of the obtained graphene fibers has been observed. The graphene fibers exhibit good electrical conductivity of 1.3 × 104 S m−1 and mechanical flexibility after heating treatment. The electrochemical performances of graphene fibers as flexible and binder-free electrodes are evaluated by using a three-electrode system and resulting in a high specific capacitance of 185.7 F g−1 at a current density of 200 mA g−1, which is mainly ascribed to the ordered, hierarchical and porous structure. The as-synthesized graphene fibers will be a promising candidate for flexible electrode materials for supercapacitors.