“Synthesis of Graphene Oxide Polypyrrole (GO PPy) from Used Batteries As Electrodes in Supercapacitor Cells”. Jurnal Kimia Valensi 5, no. 2 (November 30, 2019): 194–201. Accessed November 30, 2025. https://journal.uinjkt.ac.id/valensi/article/view/11714.