Facile stepwise hydrothermal synthesis of hierarchical CoMoO4/CoMoO4 core/shell dandelion-like nanoarrays: A promising binder-free positive electrode for high-performance asymmetric supercapacitors

Abstract

In this study, we have fabricated a flexible supercapacitor with outstanding pseudocapacitive performance using hierarchical CoMoO4/CoMoO4 core/shell dandelion-like nanoarrays. The dandelion-like CoMoO4/CoMoO4 nanostructure electrode yields a high specific capacitance (1548 F g−1 at a current density of 1 A g−1) and superior cycling stability performance (94% capability retention after 5000 cycles at 8 A g−1) in the 3 mol L–1 KOH solution. Furthermore, a flexible asymmetric supercapacitor device was assembled based on nickel foam/CoMoO4/CoMoO4 dandelion-like as positive electrode and activated carbon (AC) as negative electrode. The CoMoO4/CoMoO4 nanostructure//AC asymmetric supercapacitor device represents remarkable electrochemical performance such as good specific capacitance of 152 F g−1 and maximum energy and power densities of 54.04 Wh kg−1 and 8.83 kW kg−1, respectively. These encouraging results depict great potential in developing energy storage devices by making heterostructure nanomaterials.