High Potential of Averrhoa bilimbi Leaf Waste as Porous Activated Carbon Source for Sustainable Electrode Material Supercapacitor

Abstract

The energy cost-effective/free-environmental pollution concerns have an interest in bio-waste materials for the production of porous activated carbon, especially as electrode material for electrochemical energy storage devices such as li-ion batteries and supercapacitors. In this study, Averrhoa bilimbi leaf wastes were selected as a porous activated carbon source for sustainable electrode material supercapacitor. Porous activated carbons were prepared by chemical activation of 0.5 ml−1 sodium hydroxide solution at an optimum temperature of 800 °C pyrolyze in an environment of N2 and CO2 gases. The monolith coin shape of activated carbon is maintained by optimizing the self-adhesive properties of the precursor without the addition of adhesive materials. All coin monoliths feature a turbostratic to highly amorphous carbon structure. Furthermore, the relatively high monolith dimensional shrinkage of 42.00% initiated the development of a better pore framework carbon. In symmetric supercapacitors, electrochemical behavior confirmed a high specific capacitance of 149.04 F/g at a constant density of 1.0 A/g. Moreover, the maximum energy density was found of 10.50 Whkg−1 at an optimum power density of 116.35 W/kg in an aqueous electrolyte of 1 ml−1 Na2SO4. With bio-recycled waste, relatively easy preparation, and high electrochemical properties, porous activated carbon based on Averrhoa bilimbi leaf has great potential as a sustainable electrode material for supercapacitor energy storage applications.