A cobalt sulfide cluster-based catholyte for aqueous flow battery applicationsElectronic supplementary information (ESI) available: Synthetic procedures, UV-vis spectroscopy solubility tests, crystallographic data in CIF format, and electrochemical studies. CCDC 1848430. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8ta05788e

• Main Authors: Freeman, Matthew B, Wang, Le, Jones, Daniel S, Bejger, Christopher M
• Format: Journal Article
• Language: English
• Published: 13.11.2018
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c8ta05788e

Metal sulfide clusters are attractive components for flow batteries owing to the abundance of their constituent atoms and their tunable size, solubility, and redox properties. Here, we demonstrate that we can prepare an atomically precise cobalt sulfide cluster in a single step using low-cost precursors and water solubilizing phosphine ligands. The resulting cluster undergoes two electrochemically reversible oxidations in aqueous solutions and is stable in air. The first redox process is chemically reversible during charge-discharge experiments using a static cell and aqueous solutions of NaCl. An aqueous cell comprising methyl viologen (MV 2+ ) as the anolyte and an anion exchange membrane provides an operating V cell = 0.63 V. A water-soluble Co 6 S 8 molecular cluster was prepared and electrochemically analyzed as a potential active material for redox flow battery applications.