Fabrication and electrochemical performance of NiCo2S4/reduced graphene oxide nanocomposites for supercapacitors

Abstract

In this study RGO was used to enhance the NiCo2S4 long cycle stability The conductivity of the NiCo2S4 electrode can be increased and the mechanical strain during charge and discharge cycles is reduced by wrapping RGO with the excellent conductivity high specific surface area and special 2D morphological structure A fluffy RGO was prepared by using the Hummer's method and heat treatment and NiCo2S4 and NiCo2S4/RGO were synthesized by one-pot method The electrodes were prepared by deposition of NiCo2S4/RGO and NiCo2S4 slurry onto the nickel foam surface After 3000 times cycle charge-discharge tests the capacity retention of NiCo2S4/RGO electrode was ~ 74% which is superior to NiCo2S4 (~ 55%) Finally the as-fabricated asymmetric supercapacitors based on NiCo2S4/RGO//active carbon electrodes demonstrate a high energy density of 31 Wh/kg at a power density of 986 7 W/kg and can still maintain an energy density of 22 5 Wh/kg at a high power density of 7418 W/kg It suggests that NiCo2S4/RGO//active carbon electrodes with such high output energies and power densities are highly competitive compared to other recent reports

Date of Award	2020
Original language	English
Supervisor	Hsing-I Hsiang (Supervisor)