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 ZnCl 2 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 ZnCl 2 used in the activation process. The best material having Brunauer–Emmett–Teller specific surface area S BET = 2320 m 2 g −1 , micropore surface area S micro = 1510 m 2 g −1 and total pore volume V tot = 1.01 cm 3 g −1 where the highest amount of ZnCl 2 was used for the synthesis of carbon material. High specific parallel capacitance (140 F g −1 ), a wide region of ideal polarizability (Δ V ≤ 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.