Controllable crystal growth of NiCo-LDH nanostructure anchored on KCu7S4 nanowires via facile solvothermal method for supercapacitor application
The application of NiCo-LDHs as electrode materials for supercapacitor has evoked widespread attention. However, the pristine NiCo-LDHs always suffer from low conductivity and instability to limit the electrochemical performance in supercapacitor. Here we rationally engineered a novel KCu7S4@NiCo-LDHs core-shell structure with good capacitive performance using a simple one-step solvothermal method for electrode material of supercapacitor. The KCu7S4 nanowires act as a dependable “skeleton” for supporting the NiCo-LDH nanosheets, preventing the aggregation of NiCo-LDHs and improving the conductivity. By controlling the reaction time and the ratio of Ni/Co in the precursor solution, the results of electrochemical tasting show that the optimal composite is obtained with Ni/Co=2/1 and reaction time of 8 h, the final KCu7S4@Ni2Co1-LDHs composite possesses a high specific capacitance of 1104.5 F g-1 (122.7 mAh g-1) at 2 A g-1, good rate capability of 65.9% when the current density reach up to 10 A g-1, and long-term stability (83.5% after 1000 cycles).