Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Turkey
Approval Date: 2017
Thesis Language: Turkish
Student: Nilüfer Yıldırım
Supervisor: MUZAFFER BALBAŞI
Abstract:Today, with the increasing consumption of energy and the consumption of traditional energy sources, renewable energy sources and systems where energy is stored and used have come to the fore. Due to the increasing energy consumption and exhaust of conventional energy sources in our modern world, the use of renewable energy sources and the systems in which energy is stored in situ, gain the importance. Beside this, the use of both existing and renewable energy resources more efficiently, attempts to reduce the costs and the need for instant use have made it mandatory to store and use energy. Supercapacitors, among the electrochemical energy storage systems such as conventional capacitors and batteries have played an important role in many applications with high power densities, very short energy release time, long cycle life, environmentally friendly and stable construction. Supercapacitors, also called electrochemical double layer capacitors (EDLC), store energies by adsorption of ions in the electrolyte on porous electrodes with high surface area. There are many factors such as cell design, electrolyte, electrode surface area, pore structure, current collectors, separator, operating voltage, effecting the performance of a supercapacitor, but the key parameters are the high surface area and electrolyte among them. In this study, sub-micron sizes carbon spheres (10%) obtained by solvothermal synthesis were blended with activated carbon (80%) and PTFE (10%) and used as supercapacitor electrode material. Electrochemical tests were performed in 1.0 M H2SO4 in liquid and gel forms. The data obtained by cyclic voltammetry, galvanostatic charging / discharging method and self discharge method were used to determine the specific capacitance, specific power, specific energy and coulomb yield values. The results show that he faradic reactions do not occur on the electrode surfaces and that submicron spheres obtained by solvothermal methods can be substituted for graphite as an electrode component. At low current densities, the specific capacitance values of electrolytes in liquid and gel forms were determined as 103 F / g and 104 F / g respectively. These values were obtained as 92 F / g and 87 F / g, respectively, at high current densities. The supercapacitor with electrolyte in gel form shows 30% better self-discharge property than the one whose electrolyte is in liquid form, at 0,5 V.