A Hydroxylated Tetracationic Viologen based on Dimethylaminoethanol as a Negolyte for Aqueous Flow Batteries

A tetracationic viologen based on dimethylaminoethanol is reported as a novel negolyte for aqueous-organic flow batteries. The compound (1,1′-bis(3-((2-hydroxyethyl)dimethylammonio)propyl)-[4,4′-bipyridine]-1,1′-diium tetrachloride), termed [(DMAE-Pr)2-Vi]Cl4, was prepared by replacing the trimethylammonium groups of former analogue derivatives permanently charged moieties, improving its solubility and modifying electronic structure, revealed DFT calculations. Its electrochemical properties diffusion coefficient were investigated voltammetry DOSY. battery concept demonstrated pairing [(DMAE-Pr)2-Vi]Cl4 with TEMPOL posolyte using low-cost anion exchange membrane neutral-pH supporting electrolyte. has great potential enhancing energy density in