3D interconnected Bi2S3 nanosheets network directly grown on nickel foam as advanced performance binder-free electrode for hybrid asymmetric supercapacitor

Abstract

In this paper, we report the successful synthesis of “rock-candy” shape Bi2S3 nanocrystals and 3D interconnected Bi2S3 nanosheets network on Ni foam by a facile hydrothermal method. The structure and composition of the as-synthesized products were characterized by XRD, XPS, SEM and SEM analyses. The unique structure makes them have high electrochemical properties. At current density of 0.5 A g−1, the binder-free Bi2S3/Ni foam working electrode with high specific area possesses high specific capacity (500.8 mAh g−1) compared to pristine Bi2S3 (245.5 mAh g−1). In the actual application of Bi2S3/Ni foam, the assembled Bi2S3/Ni foam//AC hybrid asymmetric supercapacitor exhibits excellent supercapacitive performances, such as high specific capacitance (148.7 F g-1 at 1 A g−1), high energy density (45.1 Wh Kg−1 at 3202 W Kg−1), excellent cycling stability (capacitance retention is about 98.7% after 2000 cycles at a current density of 3 A g−1) and low Warburg and charge transfer resistances.