Dithiolene Complexes of First‐Row Transition Metals for Symmetric Nonaqueous Redox Flow Batteries

• DOI: 10.1002/cssc.201901702
• Publication Date: 2019-08-06T10:45:30Z
• Authors: Ross W. Hogue; Craig G. Armstrong; Kathryn E. Toghill
• Keywords: Full Papers; 540; 01 natural sciences; 0104 chemical sciences

Abstract Five metal complexes of the dithiolene ligand maleonitriledithiolate (mnt 2− ) with M=V, Fe, Co, Ni, Cu were studied as redox‐active materials for nonaqueous redox flow batteries (RFBs). All five exhibit at least two processes, making them applicable to symmetric RFBs single‐species electrolytes, that is, both negolyte and posolyte. Charge–discharge cycling in a small‐scale RFB gave modest performances [(tea) 2 V mnt ], Co ] whereas [(tea)Fe Ni (tea=tetraethylammonium) failed hold any significant capacity, indicating poor stability. Independent negolyte‐ posolyte‐only battery single couple, well UV/Vis spectroscopy, showed is stable posolyte unstable over multiple charge–discharge cycles; suffers rapid capacity fading although more robust. Identifying means stabilize 3−/2− negolyte, 2−/1− , posolytes could lead their use asymmetric RFBs.