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

Perera, Kumudu S.; Vidanapathirana, Kamal P.; Adams, Lewis J.; Hawes, Chris S.; 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. 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 5000th cycle proving the good stability of the capacitor. These findings are relevant to expanding the functionalities of SPE-based double-layer capacitors in green technologies.

Citation

Perera, K. S., Vidanapathirana, K. P., Adams, L. J., Hawes, C. S., & Balakrishnan, N. (2024). Symmetric double-layer capacitor with natural rubber and sodium salt-based solid polymer electrolyte and reduced graphene oxide electrodes. Journal of Energy Storage, 97, Article 112683. https://doi.org/10.1016/j.est.2024.112683

• Journal Article Type: Article
• Acceptance Date: Jun 16, 2024
• Online Publication Date: Jul 9, 2024
• Publication Date: Sep 1, 2024
• Deposit Date: Jul 10, 2024
• Publicly Available Date: Jul 12, 2024
• Journal: Journal of Energy Storage
• Print ISSN: 2352-152X
• Electronic ISSN: 2352-1538
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 97
• Article Number: 112683
• DOI: https://doi.org/10.1016/j.est.2024.112683
• Keywords: Reduced graphene oxide; Natural rubber; Sodium trifluoromethanesulfonate; Solid polymer electrolyte; Double-layer capacitor
• Public URL: https://keele-repository.worktribe.com/output/874739
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S2352152X24022692?via%3Dihub
• Additional Information: This article is maintained by: Elsevier; Article Title: Symmetric double-layer capacitor with natural rubber and sodium salt-based solid polymer electrolyte and reduced graphene oxide electrodes; Journal Title: Journal of Energy Storage; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.est.2024.112683; Content Type: article; Copyright: © 2024 The Authors. Published by Elsevier Ltd.