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

Abstract

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.