Radical Stabilization of a Tripyridinium-Triazine Molecule Enables Reversible Storage of Multiple Electrons
Huang, J.; Hu, S.; Yuan, X.; Xiang, Z.; Huang, M.; Wan, K.; Piao, J.; Fu, Z.; Liang, Z.
Angewandte Chemie 60(38): 20921-20925
2021
ISSN/ISBN: 1521-3773 PMID: 34288300 DOI: 10.1002/anie.202107216
Accession: 079275789
A novel organic molecule, 2,4,6-tris[1-(trimethylamonium)propyl-4-pyridiniumyl]-1,3,5-triazine hexachloride, was developed as a reversible six-electron storage electrolyte for use in an aqueous redox flow battery (ARFB). Physicochemical characterization reveals that the molecule evolves from a radical to a biradical and finally to a quinoid structure upon accepting four electrons. Both the diffusion coefficient and the rate constant were sufficiently high to run a flow battery with low concentration and kinetics polarization losses. In a demonstration unit, the assembled flow battery affords a high specific capacity of 33.0 Ah L-1 and a peak power density of 273 mW cm-2 . This work highlights the rational design of electroactive organics that can manipulate multi-electron transfer in a reversible way, which will pave the way to development of energy-dense, manageable and low-cost ARFBs.