Construction of CoMoO_4@Ni_3S_2 core-shell heterostructures nanorod arrays for high-performance supercapacitors

摘要

The core-shell CoMoO4 nanorods@Ni3S2 nanosheets (CMO@NS) for supercapacitor were prepared by a facile two-step hydrothermal process accompanying with annealing treatment. The influence of hydrothermal time on structures and electrochemical properties was studied in detail. Benefiting from the synergism-enhanced action of CoMoO4 and Ni3S2 and the novel core-shell heterostructure of the composite, the prepared electrode exhibits excellent electrochemical performance. CMO@NS employed as positive electrode for supercapacitor exhibits excellent areal specific capacitance (11.02 F cm(-2) at 5 mA cm(-2)), exceptional rate performance (70.8% retention, even increasing the current density to 30 mA cm(-2)) and enhanced cycle performance (57.7% retention rate after 3000 cycles). Furthermore, an asymmetric supercapacitor device was fabricated, which achieves an ultrahigh energy density of 0.412 mWh cm(-2) at the power density of 4 mW cm(-2) and a great cycle life with 81.25% capacitance retention over 3000 cycles. Thus, the core-shell CMO@NS could be a hopeful candidate for practical supercapacitor electrode materials.