سيداميرحسين صانعي

In order to replace non-renewable energy with renewable energy and overcome environmental problems, there is a need for energy storage devices that are efficient, affordable, and with acceptable performance. Supercapacitors are of great interest due to their unique properties such as high power density and high cycle life. The performance of supercapacitors is largely influenced by their electrode. In this research, the two-step solvothermal synthesis of CuCo2S4 electrode material was performed on the nickel foam substrate by in-situ method and the effect of solvent type (water, 1:1 and 2:1 volume ratio of ethanol and water and 2:1 volume ratio of ethylene glycol and water), amount of surfactant (0.5, 1.0 and 1.5 mmol), the type of surfactant (CTAB and PVP), the step of surfactant addition (first and second step), calcination, and the type of sulfur source were investigated. The in-situ method is a simple method with the ability to control the synthesis parameters, which does not have the limitations of the slurry method. The phase characterization of the powders obtained from the first and second step of synthesis was analyzed by X-ray diffraction analysis and the morphology of the coated electrodes with CuCo2S4 was investigated with scanning electron microscopy and high resolution transmission electron microscopy. The results of these analyzes showed the formation of Cu-Co LDH after the first step and the formation of sulfide phases with different percentages of crystallization after the second step of the synthesis. The specific surface area eva‎luated with N2 absorption/desorption analysis and electrochemical behavior of the electrodes was eva‎luated by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. Synthesis of CuCo2S4 sample in the solvent with a volume ratio of 2:1 ethanol-water and by adding 1.5 mmol of CTAB to Na2S.9H2O solution, leading to optimal conditions and creating a hierarchical porous microstructure with a very high charge-discharge capacity of 4230 F g-1 at a current density of 1 A g-1. Also, by changing the type of sulfur source and using sodium thiosulfate material, CuS/CoS2 composite was formed, which has significant electrochemical properties and a specific capacity of 2195 F g-1 in the positive potential at a current density of 1 Ag-1. The coated electrode in optimal synthesis conditions was used as the positive and negative electrodes of the symmetric supercapacitor. The supercapacitor has an energy density of 63 Wh kg-1 and a power density of 2800 W kg-1.

ابرخازن متقارن , CuCo2S4 , CTAB , PVP , رشد درجا

symmetric supercapacitor , CuCo2S4 , CTAB , In-Situ growth

Amir Hossein Sanei

Dr. Mohammad Bafghi