Controllable synthesis of CuS hollow microflowers hierarchical structures for asymmetric supercapacitors

Abstract

One of the major challenges of high-performance asymmetric supercapacitors is engineering electrode materials with high capacitance and good cycling stability. Hence, we have successfully prepared different CuS hierarchical structures including CuS tubular structures (T-CuS), CuS hollow microspheres (S-CuS) and CuS hollow microflowers (H-CuS) by adjusting the solvents, all of which are investigated as electrode materials for supercapacitors. Among them, the H-CuS electrode exhibits the best electrochemical performance involving a high capacitance of 536.7 F g−1 at a current density of 8 A g−1 and excellent cycling stability with 83.6% capacitance retention for 20,000 continuous cycles at a current density of 5 A g−1. In addition, an asymmetric supercapacitor has assembled with H-CuS as positive electrode and activated carbon (AC) as negative electrode, which exhibits a desirable energy density of 15.97 W h kg−1 when the power density is 185.4 W kg−1. These desirable electrochemical performances powerfully demonstrate that the H-CuS electrode has promising potential for applications in energy storage fields.