Electrodeposited cobalt sulfide on a vertical graphene nanocomposite for high-performance supercapacitors

Cobalt sulfide (CoS) has been widely applied in the development of high-performance supercapacitors. However, the morphological stability of CoS remains an issue during the charging-discharging processes. Herein, vertical graphene is introduced via facile electrodeposition to support CoS for the design of high-performance and stable electrodes. Since vertical graphene has a unique three-dimensional (3D) porous structure, good mechanical rigidity, and high electrical conductivity, the nanostructured CoS is tightly anchored on the vertical graphene, leading to improvement of the specific capacitance. The CoS/VG composites exhibit an impressive specific capacitance of 2649.25 F g-1 at a current density of 1 A g-1, and a drastic 150.7% retention after 3000 cycles at a current density of 10 A g-1. Such high-performance and stable CoS/VG electrodes in this work demonstrate great prospects for the development of high-performance and stable supercapacitors in a cost-effective manner.