Construction of cobalt sulfide/nickel core-branch arrays and their application as advanced electrodes for electrochemical energy storage

Abstract

Design/fabrication of advanced electrodes with tailored functionality is critical for the development of advanced electrochemical devices. Herein, we report a powerful strategy for construction of high-quality cobalt sulfide (CoS)/Ni core-branch arrays via combined methods of hydrothermal and electro-deposition. Electrodeposited thin porous Ni branch is successfully decorated on the CoS nanowires arrays with the help of hydrothermal ZnO nanorods template. Enhanced mechanical stability and improved ion/electron transfer characteristics are achieved in this composite system. As compared to the pure CoS nanowires arrays, the CoS/Ni core-branch arrays show enhanced electrochemical performance with lower polarization, better high-rate capability and superior cycling life. A high capacity of 605mAhg−1at 2C and 371mAhg−1at 6C is obtained in the composite core-branch system, respectively. Our developed electrode design protocol can be applicable for fabrication of other advanced metal sulfides electrodes for applications in solar cells, batteries and supercapacitors.