Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE A novel interlocked sandwich structure is designed to realize homogeneous composite in freestanding graphene-based fiber. To synthesize this homogeneous composite fiber, compositing–assembling process is developed. Benefiting from this structure design and new synthesis method, the active materials loading mass is effectively improved and the charge transfer process is highly modified.

ABSTRACT
Freestanding graphene-based composite fiber is generally assembled into a core-sheath structure which suffers from limited loading mass and charge transfer processes. Herein, an interlocked sandwich structure is designed to develop freestanding graphene-based homogeneous composite fiber and a novel compositing–assembling process is developed to realize the designed fiber. Firstly, polyaniline (PANI) is grown on graphene oxide (GO) sheets. The produced PANI/GO (PGO) composite is then assembled with individual GO sheets (GO′) to form GO′/PGO/GO′. The produced sandwich-structured composite sheets are further interlocked together and reduced into G/PG/G (PGR) fiber. Benefiting from this rational structure design, the PANI loading mass achieves 41.6% and the charge transfer is significantly modified. Using it for supercapacitors, the specific capacitance of the PGR fiber electrode reaches 638.5 F g−1 at 1 A g−1, and 375.9 F g−1 can be maintained at 10 A g−1. Moreover, this freestanding homogeneous composite fiber electrode exhibits excellent flexibility. After bending with an angle of 180° for 10,000 cycles, 90.55% of the capacitance can be maintained.