CuS cluster microspheres anchored on reduced graphene oxide as electrode material for asymmetric supercapacitors with outstanding performance

Abstract

Transition metal chalcogenides have been considered as promising electrode materials for high-performance supercapacitors owing to their exceptional electrical conductivity, ultrahigh specific capacity, etc. Herein, CuS/rGO composite electrode material has been rationally prepared by using a facile and efficient strategy, and the synergistic effect of CuS and rGO on the enhanced electrochemical performance is explored. The CuS/rGO electrode with diffusion-controlled feature can deliver a high specific capacitance of 1918.6 F g− 1 F g − 1 at 1 A g − 1 and as well as a long cycling life with 95.4% retention after 5000 cycles at 10 A g − 1. Charge storage analysis reveals that the dominant diffusion-controlled feature of CuS/rGO electrode is observed. Additionally, the as-synthesized asymmetric supercapacitor by using CuS/rGO electrode exhibited a maximum energy density of 51.1 Wh kg− 1 at 799.9 W kg− 1 and a maximum power density of 16007.9 W kg− 1 (for an energy density of 36.0 Wh kg− 1). Besides, it displays excellent cyclic stability with 91.3% capacity retention after 10,000 cycles at 10 A g− 1. These remarkable electrochemical performances demonstrate that CuS/rGO composite has excellent potential applications in high-efficient electrochemical supercapacitor.