Huang, Zhifeng Lee, Jongwook Henkensmeier, Dirk Hempelmann, Rolf Kim, Sangwon Chen, Ruiyong 2024-01-19T16:02:15Z 2024-01-19T16:02:15Z 2021-09-02 2020-12 0013-4651 https://pubs.kist.re.kr/handle/201004/117759 Water soluble organic redox-species have been studied in redox flow batteries as promising alternatives to overcome the limitation of current vanadium chemistry such as low energy density and high cost. Herein, a comparative physicochemical and electrochemical study of several structurally similar quinones in different molalities of imidazolium-based aqueous electrolytes highlights the importance of the molecular structure of organic solutes and their coordination with the imidazolium cations in electrolytes. A quinone derivative of 2-methoxyl-hydroquinone with a record solubility of 7.9 M at room temperature is obtained in the aqueous imidazolium-based supporting electrolyte. This is close to a maximum value of 8.13 M in its molten state, suggesting a new approach to dissolving organic-active materials. In addition, strong coordination imposes a significant effect on the chemical/electrochemical stability and redox potential of the organic quinones. The reaction kinetics and cycling performance of the 2-methoxyl-hydroquinone as catholyte in a redox flow battery have been investigated by pairing it with a vanadium anolyte (V3+/V2+ redox pair), showing a high cycling efficiency and structural stability. (c) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited. English ELECTROCHEMICAL SOC INC Effect of Molecular Structure and Coordinating Ions on the Solubility and Electrochemical Behavior of Quinone Derivatives for Aqueous Redox Flow Batteries Article 10.1149/1945-7111/abc90c 1 JOURNAL OF THE ELECTROCHEMICAL SOCIETY, v.167, no.16 JOURNAL OF THE ELECTROCHEMICAL SOCIETY 167 16 N scie scopus 000593480600001 2-s2.0-85096897273 Electrochemistry Materials Science, Coatings & Films Electrochemistry Materials Science Article ELECTRICAL ENERGY-STORAGE TEMPERATURE ELECTROLYTE CELL VOLTAMMETRY CATHOLYTE SYSTEM ROLES PH flow battery membrane quinones ionic liquids energy storage