Glutathione-Assisted Hydrothermal Synthesis and Electrochemical Performance of NiCo₂S₄ Electrode Material

As an energy storage device, supercapacitors are practically used in many fields due to their high power density and long service life. Among the components of supercapacitors, electrode materials play a key role in the performance of the device, it is thus of great significance to prepare electrode materials with superior electrochemical performance. NiCo₂S₄ was prepared by a hydrothermal method using nickel acetate and cobalt acetate as raw materials, glutathione as a morphology control agent and a sulfur source. The effect of hydrothermal reaction time on the microstructure, morphology and electrochemical performance of NiCo₂S₄ was investigated. The results show that the NiCo₂S₄ material prepared under the action of glutathione has a yolk shell structure. The specific capacitance is 1552.7 F/g when the current density is 0.5 A/g, and the specific capacitance can be maintained at 61.3% at 10A/g. After 2000 cycles, the specific capacitance retention of the material can be maintained at 79.3%. A supercapacitor can be assembled with NiCo₂S₄ and activated carbon as positive and negative electrodes, respectively. This hybrid supercapacitor can provide 33.9 W·h/kg energy density when the power density is 800 W/kg. After 2000 charge and discharge cycles, the specific capacitance retention rate is 89%.