Production of biomass-based high performance supercapacitor electrode materials and investigation of their electrochemical properties

Supercapacitors; They are energy storage devices with fast charging and discharging features and high power density. In the supercapacitor, electrodes are the most important part that affects performance. In this context, the aim of the thesis study was to develop energy storage material with electrode material produced from biomass as a sustainable, renewable, domestic and clean carbon source. Nitrogen, sulfur and phosphorus atoms were added separately to the activated carbon obtained by first pyrolysis of hemp biomass and then chemical activation with KOH. In this way, activated carbons rich in surface functional groups were obtained and their usability as high performance carbon for supercapacitor energy storage applications was investigated. The amorphization amount and microstructure of the obtained activated carbon materials were determined by Structural characterization was determined using a porosity measuring device and FTIR spectroscopy. The performances of the produced supercapacitors were tested in detail with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD) analyses. 6 M KOH aqueous electrolyte solution was used to determine the electrochemical capacitive performance of supercapacitors. The highest electrochemical performance was determined as 403 F/g in supercapacitor prepared from nitrogen-doped activated carbon. It was observed that the amorphous structure was improved by chemical activation and doping processes and the energy storage capacity was increased. Therefore, it has been proven that doped carbon electrodes obtained from economical and sustainable hemp sawdust (waste biomass) can be used in high-performance energy storage devices.