Bagasse-based Nanoporous Carbon for Supercapacitor Application

A kind of nanoporous carbon has been successfully prepared from sugarcane bagasse through a facile microwave-induced ZnCl2 activation and tested as electrode material in ionic liquid supercapacitor. The as-prepared nanoporous carbons are systematically characterized by a variety of means such as N2 adsorption, SEM (scanning electron microscope) and TEM (transmission electron microscope). Characterization results reveal that the pore size of nanoporous carbons can be tuned from 2.5 nm to 7 nm by simply adjusting the concentration of ZnCl2 solution from 20 wt% to 60 wt%. The nanoporous carbons are tested as electrode materials in ionic liquid using different electrochemical means such as cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy. As evidenced by electrochemical measurements, the capacitive performances of the carbons are closely related to their pore sizes. It has been demonstrated that large pore size benefits the good capacitive performance of nanoporous carbon in ionic liquid electrolyte.