Abstract
This work is intended to study and use carbon material obtained from tea leaf waste in energy storage systems. Microwave carbonization accompanied by physical activation in a CO2 atmosphere was used as a synthesis method. Silicon carbide was used to increase the heating efficiency to ensure uniform heat distribution in the reaction zone. The obtained activated carbon is characterized by a porous structure and good electrical conductivity. The structural and morphological properties of the samples were studied by X-ray diffraction analysis, scanning electron microscopy and Raman spectroscopy. The electrochemical characteristics were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The ФА-30 sample showed high specific capacitance (up to 152 F/g) and high stability during long-term cycling - after 3000 cycles it retained more than 75% of the initial capacity. Electrochemical impedance spectroscopy analysis showed that the porous structure of the material has a low series resistance of about 1 Ohm and a very low charge transfer resistance, which indicates good ion conductivity and fast electrochemical processes. The results obtained prove that the prepared material is promising for use in supercapacitor electrodes.