Agar-based aqueous electrolytes for electrochemical capacitors with reduced self-discharge. (1st February 2020)

• Record Type: Journal Article
• Authors: Menzel, Jakub; Frąckowiak, Elżbieta; Fic, Krzysztof
• Is Part Of: Electrochimica acta. Volume 332(2020)
• Publication Date: 2020-02-01
• Subjects: Gel-like electrolyte -- Electrochemical capacitors -- Hydrogen storage -- Aqueous solution -- Carbon electrodes; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.135435
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: This paper reports on the electrochemical performance of symmetric carbon/carbon electrochemical capacitors operating in aqueous electrolyte (0.5 mol L −1 K2 SO4 solution) and modified with various amounts of agar (up to 5 wt%). It has been found that a change in electrolyte form (from liquid to gel-like) increases the hydrogen storage efficiency on the negative electrode (confirmed by operando Raman spectroscopy), improves the cycle life at elevated voltages and reduces the self-discharge. Furthermore, it has been found that the gas generation rate during capacitor operation is remarkably diminished (by ca. 4 times), and thus, the detrimental impact of increased internal pressure is noticeably reduced. Graphical abstract: Image 1