High-performance hybrid supercapacitor realized by nitrogen-doped carbon dots modified cobalt sulfide and reduced graphene oxide

Abstract

Hybrid supercapacitor devices have elicited increasing interest because of their enormous potential for energy storage applications. Herein, a facile hydrothermal strategy was presented for the coordinative preparation of nitrogen-doped carbon dots (N-dopd CDs) modified flower-like cobalt sulfide (CoS) hierarchitectures and reduced graphene oxide nanosheets (rGO) for use as advanced cathode and anode in hybrid supercapacitor. Profiting from the merits of N-dopd CDs, the as-prepared CoS/N-dopd CDs and rGO/N-dopd CDs composites deliver enhanced specific capacitances and excellent cycle stability as compared with bare CoS and rGO. A hybrid supercapacitor device assembled by flower-like CoS/N-dopd CDs cathode and rGO/N-dopd CDs anode achieves an energy density of approximately 36.6 Wh kg−1 at 800 W kg−1 and good electrochemical stability with 85.9% retention after 10000 cycles at 10 A g−1. This study provides a new insight to coordinately design high-performance cathodes and anodes for developing new types hybrid supercapacitor devices.