STUDY THE ACTIVE-CARBON (AC)/CARBON-NANOFIBERS (CNFS) AS SUPERCAPACITOR ELECTRODES USING DIFFERENT AQUEOUS ELECTROLYTES (6 M KOH, 1 M H2SO4, AND DIFFERENT CONCENTRATIONS OF DEAD SEA WATER)
| dc.contributor.author | Kholoud Waleed Bourini | |
| dc.date.accessioned | 2024-08-13T10:10:31Z | |
| dc.date.available | 2024-08-13T10:10:31Z | |
| dc.date.issued | 2024-03-09 | |
| dc.description.abstract | This thesis explores the effects of varying electrolyte compositions on a composite AC/CNFs electrode, consisting of 90% activated carbon (AC) and 10% carbon nanofibers (CNFs), designed for supercapacitors. Four different electrolytes were employed: 6 M potassium hydroxide (KOH), 1 M sulfuric acid (H2SO4), Dead Sea water, and concentrated Dead Sea water. The electrode's electrochemical properties were analyzed using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). In CV tests conducted at a 100 mV/s scan rate, the electrodes exhibited specific capacitances (Cs) close to each other with values at 78.50 F/g for H2SO4, 77.40 F/g for KOH, and 78.54 F/g for Dead Sea water. However, the electrode with concentrated Dead Sea water recorded a lower Cs of 56.54 F/g. At a lower scan rate of 5 mV/s, the Cs increased, with KOH showing the highest capacitance of 157.86 F/g, while the other electrolytes recorded slightly lower values. GCD studies indicated a decrease in Cs with higher current densities. At a low current density of 0.4 A/g, concentrated Dead Sea water electrolyte showed the highest Cs of 84.40 F/g, contrasting with the lowest Cs of 52.40 F/g for the KOH electrolyte. Other electrolytes exhibited similar capacitance around 81 F/g at this current density. The stability tests confirmed that all electrodes maintained their performance over numerous cycles, highlighting their potential for long-term supercapacitor applications. EIS measurements revealed that the electrodes with 1 M H2SO4 showed the highest specific capacitance of 150.3 F/g. The concentrated Dead Sea water electrolyte exhibited the fastest charge transfer, indicated by the highest knee frequency at 0.125 Hz. The electrode with regular Dead Sea water displayed the lowest time constant, suggesting quicker charging and discharging capabilities. Impedance values and phase angles further confirmed diverse capacitive behaviors across the electrolytes, with the regular Dead Sea water electrode showing characteristics closest to ideal capacitive behavior. Surface examination of the AC/CNFs electrode revealed a coarse and porous structure, predominantly narrow, slit-like micropores, with a total pore volume of 0.693 cm3/g and a specific surface area of 962.06 m2/g. These physical attributes are crucial for the electrode's performance in supercapacitors. Keywords: Active Carbon (AC), Carbon Nanofibers (CNFs), Supercapacitor Electrodes, Aqueous Electrolytes, Dead Sea Water. | |
| dc.identifier.uri | https://hdl.handle.net/20.500.11888/19291 | |
| dc.language.iso | en | |
| dc.supervisor | Dr. Allan Daraghmeh Dr. Iyad Saadeddin | |
| dc.title | STUDY THE ACTIVE-CARBON (AC)/CARBON-NANOFIBERS (CNFS) AS SUPERCAPACITOR ELECTRODES USING DIFFERENT AQUEOUS ELECTROLYTES (6 M KOH, 1 M H2SO4, AND DIFFERENT CONCENTRATIONS OF DEAD SEA WATER) | |
| dc.type | Thesis |