Facile synthesis of hierarchical CoMoO4@NiMoO4 core-shell nanosheet arrays on nickel foam as an advanced electrode for asymmetric supercapacitors

摘要

Hierarchical CoMoO4@NiMoO4 core-shell nanosheet arrays were successfully grown on nickel foam via a facile two-step hydrothermal method followed by calcination treatment. With an ordered core-shell nanostructure and a desired composition, the optimized CoMoO4@NiMoO4 composite electrode exhibited a high specific capacitance of 1639.8 F g(-1) (3.30 F cm(-2)) and an excellent cycling stability with a 95% retention rate at a high current density of 20 mA cm(-2) after 3000 cycles. Additionally, an asymmetric supercapacitor (ASC) was assembled with CoMoO4@NiMoO4 nanosheet arrays/Ni foam as the positive electrode and activated carbon (AC) as the negative electrode, which displayed an energy density of 28.7 W h kg(-1) at a power density of 267 W kg(-1). The remarkable electrochemical performance indicated that the CoMoO4@NiMoO4 composite was a promising electrode material and had great application potential for energy storage.