Effect of Solid Polymer Electrolyte Based on Corn Starch and Lanthanum Nitrate on The Electrochemical Performance of SupercapacitorNadia Parwaty Wijanarko, Dwi Wulandari, Mohammad Helmi Arrafii, Sylvia Ayu Pradanawati, Yatim Lailun Ni’mah, Lukman Noerochim and Nur Laila HamidahBIO Web Conf., 89 (2024) 03001DOI: https://doi.org/10.1051/bioconf/20248903001