Extraction of Carbon Based Biochar fromWasted Biomass for Energy Storage Application

Abstract

The growing need for powerful eco-friendly energy storage has determined research into better electrode materials for supercapacitors. Supercapacitors famous for their fast charge and discharge cycles and high-power output, but their energy storage capacity remains relatively low, when relying on Bismuth Sulfide (Bi₂S₃). To solve this, we use Biochar, a carbon-rich material that can both store more electrons and also facilitates fast electron transport. In this study, we created a binder-free electrode by growing Bi₂S₃ directly onto Biochar made from Amal Tass pods biomass waste, using a fast microwave-assisted process. First, we turned the Amal Tass pods into conductive biochar through drying, grinding, and a simple hydrothermal step. Then mixed this biochar into water with Bi(NO₃)₃·5H₂O and thiourea, and exposed the mixture to microwave energy and a uniform Bi₂S₃–Biochar composite formed, no binders or extra additives needed. This composite delivers a high energy density, making it a strong candidate to replace batteries. Raman spectroscopy confirmed that Bi₂S₃ adopted its orthorhombic crystal structure within the carbon matrix, and it also showed the characteristic D- and G-bands of biochar at 1391 and 1595 cm⁻¹. When we tested the composite in 2 M KOH, cyclic voltammetry revealed clear redox peaks whose areas raised with scan rate, indicating strong pseudocapacitive behavior. Electrochemical impedance spectroscopy showed low charge-transfer resistance, which means ions and electrons move through the material with ease. Together, these results demonstrate that our quick, green microwave method produces Bi₂S₃–Biochar electrodes that combine high power with improved energy storage an encouraging step toward the next generation of sustainable pseudocapacitors.