Abstract
The application of NiCo_2O_4 as electrode materials for supercapacitors has attracted widespread attention. However, pristine NiCo_2O_4 always suffer from poor electrical conductivity and rate performance that limit their electrochemical performance in supercapacitors. In order to overcome the deficiencies of NiCo_2O_4, in this study, we successfully synthesized KCu_7S_4@NiCo_2O_4 core-shell structure in-situ grown on Ni foam with good electrochemical performance. The morphologies of KCu_7S_4@NiCo_2O_4 composite could be controlled by electrochemical deposition time. According to the electrochemical testing results, an optimal composite was obtained with the deposition time of 10 min, and the corresponding KCu_7S_4@NiCo_2O_4 composite possessed the high specific capacitance of 18.4 F cm~(-2) (2008 F g~(-1)) at a current density of 3 mA cm~(-2) and good cycling stability (80% capacitance retention after 4000 cycles at a current density of 40 mA cm~(-2)). Moreover, the investigation demonstrates the great potential application of KCu_7S_4 @NiCo_2O_4 in supercapacitor. The asymmetric supercapacitor fabricated with KCu_7S_4@NiCo_2O_4 and activated carbon delivers a high energy density of 125.56 Wh kg~(-1) at the power density of 105.5 W kg~(-1).
NSTL
Elsevier