Synthesis of Activated Carbon from Salacca Peel with Hydrothermal Carbonization for Supercapacitor Application
Ashianti Stenny Winata (a), Ratna Frida Susanti (b*), Hary Devianto (a)
(a) Department of Chemical Engineering
Institut Teknologi Bandung, Bandung 40132 Indonesia
(b) Department of Chemical Engineering
Universitas Katolik Parahyangan, Bandung 40141 Indonesia
*santi[at]unpar.ac.id
Abstract
Supercapacitor is considered as promising technology in energy storage system (EES) because of high power, large currents, and excellent cycle stability. In this study, activated carbon was used as the constituent material for electrodes because it owns porous structure with large surface area, owns high conductivity, low cost, and renewable Activated carbon was synthesized from salacca peel by hydrothermal carbonization and chemical activation with KOH. Salacca peel was chosen as a precursor because it has high fixed carbon content and low ash content, but usually discarded as a waste. This research focused on the effect of operating pressure in the hydrothermal carbonization process. The the operating pressure used will determine the water phase in the hydrothermal process, where in this study the pressure is adjusted so that the water is varied in the vapor phase and liquid phase (subcritical water). In hydrothermal carbonization, temperature was varied at 225oC and 250oC with the carbonization time of 5 hours. Chemical activation using KOH as activating agent was done after obtained the hydrochar from hydrothermal carbonization process. Produced activated carbons were characterized by nitrogen adsorption-desorption, scanning electron microscope, Fourier transform infrared, X-ray diffraction, and Raman spectroscopy. Electrochemical properties of these carbons were characterized by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. It is found that the largest surface area of produced activated carbons could be obtained is 2907.31 m2/g and the largest capacitance of supercapacitor is 15.57 F/g.
Keywords: activated carbon; salacca peel; hydrothermal carbonization; subcritical water; supercapacitor
Topic: Functional Materials