Carbon Quantum Dots Derived from Spent Local Liberica Coffee Ground for Applications in Electric Double-layer Capacitor (EDLC)

This study aims to repurpose spent coffee grounds biomass to produce carbon quantum dots (CQDs).These CQDs are then utilized in energy storage systems for sustainable and environmentally friendly purposes due to their ability to increase the device's surface area, biocompatibility, and good optical and electrical properties.Various characterizations, including XRD, TEM, LSV, CV, and GCD, are performed.The synthesized CQDs from the hydrothermal process are incorporated into a carbon slurry and then used as electrodes in electric double-layer capacitor devices assembled with an optimized polyvinyl alcohol gel electrolyte, resulting in a specific capacitance of 125 F/g. Synthesis of CQDs Preparation of GPEAluminium substrate (Current collector) Aluminium substrate (Current collector) Activated Carbon + PVdF + CQDs + Super P Gel polymer electrolyte film