Studies about supercapacitors are being target in researches, which want new devices that can optimize or even replace the Li-Ion batteries. The two most important drawbacks in batteries are the reduced cycle life and low operating power, both being due to the occurrence of faradaic reactions. On the other hand, electrochemical double layer capacitors are capable to operate at high power for hundreds of thousands cycles more. Although both devices present different charge storage mechanism, both move to the same direction: to raise energy and power. To do that, it must be analysed ways to increase the power and to enlarge the operation window of the cell. The focus to that problem must be on the main material that the operating voltage depends on: the electrolyte. The mixture of ionic liquids can be one of the steps to overcome this obstacle, once that it can enhance the physical chemical characteristics, the conductivity and the electrochemical stability. In this project, mixtures of ionic liquids will be prepared and their physicochemical properties will be measured and analysed (viscosity, density and ionic conductivity). Moreover, analyses of electrochemical cells utilising two and three electrodes cells will be performed, making possible to generate useful data for analyses, for example the maximum operating voltage and the relationship of charge per mass of the electrode for cells optimization. The main objective in this project is to provide data that shows the influence of the mixtures of ionic liquids on the capacitance of the supercapacitors.
News published in Agência FAPESP Newsletter about the scholarship: