▎ 摘　　要

Benefiting from high flexibility and weavability, the wire-shaped supercapacitors (SCs) arouse tremendous interests for the applications in wearable/portable electronics. Graphene fiber (GF) is considered as a promising linear electrode for wire-shaped SCs. However, the bottleneck is how to develop the GF-based linear electrode with facile fabrication process while well-maintaining satisfactory electrochemical performance. Herein, a novel Fe3O4@GF composite linear electrode is proposed via a chemical reduction-induced assembly approach, in which the GO and Fe3O4 nanoparticles (NPs) realize the efficient self-assembly owing to the electrostatic and van der Waals interactions, as well as the sufficient reduction of GO during the preparation process. The resultant fiber-shaped architecture shows boosted charge-transfer kinetics, high flexibility and structural integrity. Such Fe3O4@GF linear electrode exhibits excellent electrochemical behaviors including a large volumetric specific capacitance (similar to 250.75 F cm(-3)), remarkable rate capability and favorable electrochemical kinetics in aqueous electrolyte, superior than previously reported GF-based linear electrodes. For real application, a high-performance wire-shaped SC with excellent flexibility and weavability is fabricated based on such Fe3O4@GF linear electrode and gel electrolyte, demonstrating ultrahigh volumetric energy density (18.8 mWh cm(-3)), power density (4000 mW cm(-3)) and strong durability (similar to 93.5% retention after 10000 cycles). Prospectively, the fabricated wire-shaped SC can maintain reliable electrochemical behaviors in various deformation states, showing its potentials in future portable and wearable devices.