A non-aqueous all-copper redox flow battery with highly soluble active species. (10th May 2017)

• Record Type: Journal Article
• Authors: Li, Yun; Sniekers, Jeroen; Malaquias, João; Li, Xianfeng; Schaltin, Stijn; Stappers, Linda; Binnemans, Koen; Fransaer, Jan; Vankelecom, Ivo F.J.
• Is Part Of: Electrochimica acta. Volume 236(2017)
• Page Start: 116
• Page End: 121
• Publication Date: 2017-05-10
• Subjects: Energy storage -- Redox flow battery -- Copper -- Ionic liquids -- Liquid metal salts; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.03.039
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: A metal-based redox pair with acetonitrile as ligand [Cu(MeCN)4 ][Tf2 N] is described for use in non-aqueous redox flow battery (RFB). The electrode kinetics of the anode and cathode are studied using cyclic voltammetry. The Cu 2+ /Cu + and Cu + /Cu couples in this system yield a cell potential of 1.24 V. The diffusion coefficient for [Cu(MeCN)4 ][Tf2 N] in acetonitrile is estimated to be 6.8 × 10 −6 cm 2 s −1 at room temperature. The copper-acetonitrile complex has a very high solubility of 1.68 M in acetonitrile, the most widely used organic solvent for non-aqueous electrochemical applications. Hence, a maximum theoretical energy density around 28 Wh L −1 can be reached with the reported system. The RFB with this electrolyte shows a promising performance, with coulombic efficiencies of 87% and energy efficiencies of 44% (5 mA cm −2 ).