The team used water, ethanol, and a mixture of both as solvent to make different cobalt sulfide electrodes. They used X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy and other techniques to analyze the different properties of cobalt sulfide nanoparticles in the crystal properties, chemical state and surface morphology, and with cyclic voltammetry, constant current Charge-discharge method and electrochemical impedance spectroscopy methods were used to evaluate the electrochemical properties of cobalt sulfide electrode. The results show that the electrode with ethanol as the cobalt sulfide electrode showed the best capacitance characteristics.
The researchers believe that ethanol-based cobalt sulfide electrode, due to ethanol solvent has a more suitable surface morphology, the electrolyte ions more easily spread to the electrode, the conductivity increases, which showed the characteristics of supercapacitors.
New research shows that cobalt sulphide nanoparticles have broad application prospects in the fields of photocatalysis, electrocatalysis, water decomposition and solar cells, as well as various energy storage devices, and are superior anode materials for making supercapacitors.