Investigation of the Capacitive Properties of Chemically Activated Sugarcane Bagasse Biochar for Supercapacitor Application

In this study, sugarcane bagasse, an abundantly available agro-industrial waste was pyrolyzed into biochar, and activated carbon was produced. Experiments were performed to evaluate the potential of activated biochar carbon as an electrode material in supercapacitor. KOH activated biochar carbon showed a higher surface area of 2336.45 m2g – 1. Further electrochemical measurements of the activated carbon show that the material exhibited better performances compared to some of the reported carbon materials derived from biomass, that were utilized in supercapacitor electrodes. The activated carbon electrode showed a high specific capacitance of 197.33 Fg – 1 at a scan rate of 1 mVs – 1 in 1.5 M KOH electrolyte. Moreover, the electrode displayed good initial capacitance retention, which is 65 % after 1000 cycles. The electrode prepared using non-activated biochar carbon exhibited poor performance and was not considered for any other electrochemical measurements except cyclic voltammetry. The maximum specific capacitance of the non-activated carbon electrode in cyclic voltammetry was found to be 13.88 Fg – 1 at a scan rate of 1 mVs – 1. The galvanostatic charge/discharge test of the activated biochar electrode displayed a better charge-discharge mechanism and the GCD curve slightly resembled the ideal triangular shape. Maximum energy and power densities shown by the electrode of activated carbon were 17.57 Whkg – 1 and 2.06 kWkg – 1. The high surface area of activated carbon having mesoporous structure is significant for this electrochemical characteristic of the prepared electrode. The study indicates that sugarcane bagasse has the potential to use it as raw material for the preparation of activated biochar carbon for its application in supercapacitor.