Fabrication of nanoflower-like Ni₂Co-S/C_NTA with morphology controlled for high-performance supercapacitor

Morphology and structure regulation is considered to be an effective strategy to improve the energy storage performance of supercapacitor electrode materials. In this work, a series of graded Ni2Co-S/C-NTA nanoflowers composed of self-assembled nanosheets or nanorods have been synthesized by nitrilotriacetic acid (NTA)-assisted hydrothermal strategy. Morphological analysis shows that the micromorphology of the unit structures made up nanoflowers can be controlled by adjusting the concentration of NTA. Thanks to the synergistic effect of high void space, hierarchical assembly mode and integrated composite structure, Ni2Co-S/C-NTA nanoflowers promote the full exposure of rich active sites, it enhances the stability of the structure, and impart excellent energy storage performance. As expected, the optimized Ni2Co-S/C-NTA-2 electrode exhibits excellent capacitive performance, including high specific capacitance (1670.2 F g(-1) at 1.0 A g(-1)) and good cycle stability (86.5% after 5000 cycles). The maximum energy density of Ni2Co-S/C-NTA-2//AC ASC device is 61.3 Whkg(-1) at a power density of 816.7 Wkg(-1) and its retention rate is 88.3% after 5000 cycles.