Eggshell-Derived Activated Carbon as Sustainable Electrode Material for High-Performance Supercapacitors

In this study, I demonstrate a cost-effective and environmentally sustainable approach to synthesizing high-performance porous carbon for supercapacitor electrodes using eggshell waste as a natural templating agent. By systematically optimizing the fructose-to-eggshell ratio (0.5:1, 1:1, 2:1 and 4:1), I achieved tailored porosity and enhanced electrochemical properties. Comprehensive characterization (FT-IR, BET, XRD) revealed that chemical activation boosted the specific surface area from ~21 m 2 /g to >500 m 2 /g, with an ideal mesoporous structure suitable for rapid ion transport (5.0-5.2 nm pore size). The optimal sample (1:1 ratio, Ca-2.act) delivered a capacitance of 76.1 mF/cm 2 at 10 μA, as confirmed by GCD and CV analysis. This work not only presents a green alternative to conventional templating methods but also highlights the dual benefits of waste valorization and sustainable energy storage, positioning eggshell-derived carbon as a viable material for next-generation supercapacitors.