Electrochemical Performances Investigation of New Carbon-Coated Nickel Sulfides as Electrode Material for Supercapacitors

摘要

A new carbon-coated nickel sulfides electrode material (NST/CNTs@C) has been synthesized through an easy-to-operate process: NiS /CNTs which was prepared by a hydrothermal method reacted with BTC (1,3,5-benzenetricarboxylic acid) under the condition of water bath heating to obtain the precursor, and then the precursor was calcined in 450 °C under a nitrogen atmosphere to obtain NST/CNTs@C. The electrochemical performance of NST/CNTs@C has been greatly improved because the formation of a carbon-coated layer effectively increased the specific surface area, reduced the charge transport resistance and inhibited the morphological change of nickel sulfides in the charge–discharge process. Compared with pure NiS and NiS /CNTs, NST/CNTs@C presented great specific capacitance (620 F·g at a current density of 1 A·g ), better cycle stability (49.19% capacitance retention after 1000 cycles) and more superior rate capability (when the current density was raised to 10 A·g the specific capacitance remained 275 F·g ).