Facile Synthesis of Ag‐Decorated Ni3S2 Nanosheets with 3D Bush Structure Grown on rGO and Its Application as Positive Electrode Material in Asymmetric Supercapacitor

Abstract

AbstractA facile and cost‐effective route is developed for synthesizing 3D bush structure of Ag nanoparticles‐decorated Ni3S2 grown on reduced graphene oxide (rGO) for the first time. In this composite, Ni3S2 exhibits nanosheet networks with porous feature. The electrochemical measurements display that the as‐prepared rGO/Ag/Ni3S2 composite possesses a superior areal capacitance of 5920 mF cm−2 at current density of 5 mA cm−2. 77.5% of the initial areal capacitance is retained as current density increased from 5 to 20 mA cm−2. Encouragingly, this electrode exhibits excellent cycle performance with 94% capacitance retention after 3000 cycles at a current density of 30 mA cm−2, whereas for rGO/Ni3S2 composite electrode, only 84.7% of the initial value is maintained. The enhanced conductivity and unique structure of rGO/Ag/Ni3S2 composite attribute to its superior electrochemical performance. In addition, an aqueous asymmetric supercapacitor is fabricated using rGO/Ag/Ni3S2 composite as positive electrode and the nitrogen‐doped graphene as negative electrode. The assembled device delivers high energy density of 28.7 Wh kg−1 at a power density of 425 W kg−1. This work may prompt the development and application of active materials decorated with highly conductive nanoparticles in supercapacitors.