Abstract: The composite of three-dimensional flower-like layered double hydroxides (LDH) with carbon black (CB) was prepared by solvothermal method using ethanol as the solvent. X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM) were used to characterize the structure and morphology of the samples. Cyclic voltammetry, AC impedance, constant current charge and discharge were used to analyze the electrochemical properties of materials. The results show that the prepared NiCo-LDH/CB and NiCo-LDH/CB-D electrodes have specific capacitances of 1 520 F·g^-1 and 2 127 F·g^-1 at a current density of 1 A·g^-1 respectively when used as electrode materials for supercapacitors. Even at the high current density of 7 A·g^-1, their specific capacitance can still reach 1 438 F·g^-1 and 2 011 F·g^-1, and the capacity retention rate is 94.6% and 94.5%. Compared with pure flower-like NiCo-LDH, the introduction of CB significantly improves the electrochemical performance of the material.

Key words: supercapacitor, NiCo-LDH/CB composite, flower-like NiCo-LDH, solvothermal method, electrochemical performance, specific capacitance