Symmetric double-layer capacitor with natural rubber and sodium salt-based solid polymer electrolyte and reduced graphene oxide electrodes

Balakrishnan, Nilanthy

Abstract

Solid polymer electrolytes (SPEs) are the key to improving electrochemical devices' energy density and safety. In recent years, natural polymers have received tremendous attention due to the latest advances in green technology for a sustainable future. Herein, SPEs based on 49% methyl grafted natural rubber (MG49-NR) and sodium trifluoromethanesulfonate (Na(CF3SO3) – NaTF) salt were prepared and characterized to optimize their performance [1]. The composition MG49-NR: NaTF = 1:0.5 (by weight) shows the highest room temperature conductivity (σRT) of 7.52 ´ 10-4 S cm-1. This optimized electrolyte is purely an ionic conductor with an activation energy (Ea) of 0.29 eV. The optimized electrolyte was used to fabricate double-layer capacitors by sandwiching it between two identical reduced graphene oxide (rGO) electrodes. The fabricated double-layer capacitors show a maximum single electrode specific capacitance (Csc) of 42.5 F g-1 from the cyclic voltammetry (CV) test. Moreover, the charge storage mechanism utterly takes place via non-faradaic reactions which is evidenced by cyclic voltammograms. Furthermore, the electrochemical impedance spectroscopy (EIS) test shows the capacitive features are dominant at low frequencies. Performance of the double-layer capacitor during 10,000 charge and discharge cycles at a constant current density of 0.05 A g-1 shows a fast drop of single electrode specific discharge capacitance (Csd) at the beginning, but it started to saturate after the 5,000th cycle proving the good stability of the capacitor. These findings are relevant to expanding the functionalities of double-layer capacitors having natural rubber-based SPEs in green technologies.

Citation

Balakrishnan, N. (2025, June). Symmetric double-layer capacitor with natural rubber and sodium salt-based solid polymer electrolyte and reduced graphene oxide electrodes. Presented at International Conference on Sustainable Chemistry for Net Zero, University of St Andrews, Scotland, UK

• Presentation Conference Type: Conference Abstract
• Conference Name: International Conference on Sustainable Chemistry for Net Zero
• Start Date: Jun 10, 2025
• End Date: Jun 13, 2025
• Acceptance Date: Jan 23, 2025
• Online Publication Date: Jun 5, 2025
• Publication Date: Jun 5, 2025
• Deposit Date: Jun 5, 2025
• Peer Reviewed: Peer Reviewed
• Public URL: https://keele-repository.worktribe.com/output/1276349