Effect of Functionalized Ionic Liquids on the Stability of V(acac)3

[摘要] V(acac)3, one of the most promising candidates for the active material of non‐aqueous RFB, has various drawbacks such as the change of color, precipitation, and lowering capacity during RFB operation due to the sensitiveness of V(acac)3 to oxygen. The stability of V(acac)3 under air was studied using electrochemical analysis, FT‐IR, UV–Vis, and XPS spectroscopic methods. The 0.01 M solution of V(acac)3 turns to VO(acac)2 in 3 days under air implying that V(acac)3 is sensitive to the O2 (g) in the air. The ionic liquid (IL) containing functional group was added to V(acac)3 solution as the supporting electrolyte. Although the addition of IL, bearing the electron withdrawing group(s) on the cation, almost did not affect the stability of V(acac)3, the stability of V(acac)3 was significantly increased up to 7 days in the presence of IL containing an electron donating group on the cation.

[学科分类] 化学（综合）

[关键词] Ionic liquid;Non‐aqueous;Redox flow battery;Stability;Vanadium complex