Synthesis of flower-like Co3O4@NiCo2S4 heterostructure composites for high performance supercapacitors
摘要
With the increasing demand for energy conservation and environmental protection, supercapacitors have attracted considerable attention due to their superior advantages. In this study, the Co3O4@NiCo2S4 heterostructure composite materials have been synthesized by combining hydrothermal and electrodeposition techniques. The unique core–shell heterostructures significantly enhanced the electron migration rate and electrolyte ion diffusion. The prepared magnolia-like Co3O4 exhibited specific capacitance of 850 F g−1 at discharge current density of 0.5 A g−1 and capacitance retention of 89.3% after 10,000 continuous cycles at 1 A g−1, possessing favorable cycling stability. The Co3O4@NiCo2S4 composites presented excellent electrochemical performance, exhibiting a high specific capacitance (1552 F g−1 at 0.5 A g−1 and 1093 F g−1 at 20 A g−1) and remarkable cycle stability (92.6% retention after 10,000 cycles and 84.4% after 20,000 cycles). In addition, the Co3O4@NiCo2S4//activated carbon asymmetric supercapacitor (Co3O4@NiCo2S4//AC ASC) device was fabricated. The specific capacitance retention of 87.6% was obtained after 20,000 continuous cycles at 1 A g−1. Furthermore, the maximum energy density and power density reached 65.3 Wh kg−1 and 16,000 W kg−1, respectively. These findings indicated the developed Co3O4@NiCo2S4 composites have significant potential application in energy storage fields.