Electrochemical performance of Quercus infectoria as a supercapacitor carbon electrode material

Abstract

In order to eliminate disadvantages of conventional capacitors and batteries, supercapacitors have become very popular lately. Carbon-based biomass materials show great promise as supercapacitor electrode materials due to their high stability, good electronic conductivity, and porous structure. In this study, Quercus infectoria (Qui) biomass was converted to activated carbon for the first time using carbonization and different acid-base activations. Three supercapacitor cells with two-electrode system were designed using these activated carbons. As a result of activation with KOH, the capacitance values increased 3-fold for 1 A/g, and a high capacitance value of 89 F/g was obtained, thanks to the increasing of pore volume and the expansion of the surface area. After 110 cycles, the Qui-KOH electrode still maintained 92.1% of its capacitance value. Qui-KOH had a maximum energy density of 8.46 Wh/kg at a power density of 407.64 W/kg, much higher than the energy density of other electrodes. An increase in coulombic efficiency was observed after 110 cycles of all electrodes, and for the Qui-KOH, it rised to 92.77%. The developed electrodes offer new potential in the field of energy storage since they are inexpensive, ecologically friendly, efficient, high-capacity, and stable.