Hierarchical construction of polyaniline nanorods on sulfonated graphene for high-performance supercapacitors

Herein, polyaniline (PANI)/sulfonated graphene (SG) hierarchical composites was prepared through the growth of polyaniline nanorods on the surface of SG. The morphology and structure of the composites were analyzed by scanning electron microscopy, fourier transform infrared spectroscopy, raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. It was found that SG was beneficial to the form of uniform PANI nanorods, and strong interactions could be formed between them. Due to the synergistic effect between PANI and SG, The SG/PANI composite electrode exhibited excellent electrochemical performances, especially extraordinarily high-rate capability. When the current density increased to 50 A g−1, SG/PANI with 81.5% PANI presented a high specific capacitance of 477.5 F g−1, which remained 86.3% of its initial value at 0.5 A g−1. The cycle life test show the composites have excellent stability (still remain 96.7%) after 2000 cycles. Moreover, an asymmetric supercapacitor was assembled coupling with graphene, which demonstrated remarkable specific energy density and power density simultaneously. The highest values could achieve 56.34 Wh kg−1 and 1200 W kg−1.