Effect of Zinc Chloride Activation on D-Glucose Derived Carbons Based Capacitors Performance in Ionic Liquid

Abstract

Various carbon materials have been synthesized applying hydrothermal carbonization process and subsequent ZnCl2 activation step using different mass ratios of activating reagent. The resulting powder materials were characterized physically and electrochemically in a two-electrode cell configuration using 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid. Activated materials porosity was highly dependent on the activation conditions i.e. on the ratio of ZnCl2 used in the activation process. The best material having Brunauer–Emmett–Teller specific surface area SBET = 2320 m2 g−1, micropore surface area Smicro = 1510 m2 g−1 and total pore volume Vtot = 1.01 cm3 g−1 where the highest amount of ZnCl2 was used for the synthesis of carbon material. High specific parallel capacitance (140 F g−1), a wide region of ideal polarizability (ΔV ≤ 3.0 V), short characteristic relaxation time (2.12 s), and high energy density (48 W h kg−1) values have been established for material with the highest porosity showing great potential for these supercapacitor systems to be used in practical application as energy storage devices.