High electrochemical performance in asymmetric supercapacitors using MWCNT/nickel sulfide composite and graphene nanoplatelets as electrodes

Abstract

The electrochemical performance of asymmetric supercapacitors (ASCs) using MWCNT/NiS and graphene nanoplatelets as the positive and negative electrode, respectively, are reported. Nickel sulfide nanoparticles can be decorated on multiwall carbon nanotubes using a hydrothermal synthesis process, with graphene nanoplatelets obtained via a chemical route. The fabricated ACSs were operated over a potential window of 1.4 V with a specific capacitance of 181 F g⁻¹ observed at 1 A g⁻¹. The ASCs were cycled at 2 A g⁻¹ showing 92% retention of initial capacitance after 1000 cycles.