Electrochemical Exfoliation of Spent Dry Cell Battery Electrodes and Green Reduction of Graphene Oxide Using Palm Oil Leaf Extract for Supercapacitor Application

This study presents a sustainable method for recycling zinc–carbon batteries by electrochemically exfoliating spent graphite electrodes to produce graphene oxide (GO), followed by green reduction with palm oil leaf extract to form reduced graphene oxide (rGO). GO sheets were exfoliated from graphite electrodes under varying applied potentials, and the palm oil leaf extract served as a green reducing agent for GO. The physical, morphological, and electrochemical properties of the rGO were characterized, revealing that exfoliation at 4.5 V yields high-quality GO. The resulting rGO outperformed GO in supercapacitor applications, demonstrating a significantly higher specific capacitance of 35.5 F g⁻¹ compared to GO’s 0.5 F g⁻¹. This eco-friendly approach not only enhances the electrical conductivity and stability of the recycled rGO but also contributes to sustainable material development for high-performance energy storage applications.