الفهرس 
List of PublicationsOnly 14 pages are availabe for public view
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Abstract
Supercapacitors (SCs), also called ultracapacitors, have attracted the widespread attention of researchers because of their ability to store energy with very high power density. Graphite (g) as conductive additive material was dosed to activated carbon as semiconductor material to increase its conductivity and potassium Bromide (KBr) was subsequently dosed to an aqueous electrolyte solution that improved the capacitive performance and energy storage for symmetrical supercapacitor devices. The presence of halogen atom exhibited large faradaic resembling battery-like-type in charge/discharge curves. Double layer capacitor electrodes including activated carbon as semiconductor material with multi-walled carbon nanotube as a conductive additive material (AC/MWCNTs) and pseudocapacitor electrode with Nano-structural porous manganese oxide (NP-MnO2) have been used to improve the capacitive performance of the negative (N-ve) and positive (P+ve) electrodes for asymmetric hybrid supercapacitor. Cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), electrochemical impedance spectroscopy (EIS) techniques were employed for measuring the electrochemical characterization of the individual electrodes and supercapacitor cell. AC/AC symmetric supercapacitor cell demonstrated excellent electrochemical performance, including specific energy of 57.15 Wh kg-1, specific capacitance of 127 F g-1, specific power of 5262 W kg-1 at a specific current of 3.8 A g-1, and 82.8% capacitance retention after 10,000 cycles. The asymmetric NP-MnO2//AC/MWCNTs hybrid supercapacitor device manifests a wide working potential window (0 - 1.8 V) and highest specific energy of 50 Wh kg-1 with a specific power of 1085 W kg-1 at 1 A g-1. After 10000 cycles at 12 A g-1, an excellent cycling stability behavior with 95 % capacitance retention was obtained.