Activated carbon synthesized from Jack wood biochar for high performing biomass derived composite double layer supercapacitors

Abstract

In this study, the electrochemical properties of bioderived activated carbon-based electrodes for supercapacitors formed using a sintered ceramic binder were investigated. Activated carbon derived from Jack wood tree (Artocarpus heterophyllus) with variable amounts of TiO₂ nanoparticles as a binder, were used as electrodes in order to get good, activated carbon films on FTO substrates. No other binders were used in this study since most conventional binders devastate the electrical conductivity in the films. Furthermore, TiO₂ has higher temperature tolerance compared to polymeric binders thus the electrode prepared can be used in wider applications. A series of electrochemical double-layer capacitors were fabricated and characterized by cyclic voltammetry and galvanostatic charge-discharge measurements. The supercapacitors prepared showed double-layer capacitive behavior. The electrodes that contain 90 % activated carbon and 10 % TiO₂ show optimum performance along with an impressive specific capacitance of 147 F g⁻¹ at 2 mV s⁻¹ scan rate. This supercapacitor exhibits a power density of 68.5 W kg⁻¹ while the energy density is 8.02 Wh kg⁻¹. When the power density is as high as 1186.51 W kg⁻¹ the energy density drops to 5.71 Wh kg⁻¹. According to cyclic voltammetry measurements taken for 1000 cycles, the supercapacitor shows excellent cycle stability without any traces of capacitance drop.