A Low‐Permeability TEMPO‐Phosphate as an Anionic Posolyte for Aqueous Redox‐Flow Batteries
Abstract
ABSTRACT TEMPO is an attractive aqueous redox‐flow battery material but requires the installation of dedicated ionic groups to improve solubility and prevent crossover through ion‐exchange membranes. Although many cationic solubilizing groups have been reported, the library of anionic groups is limited. Here, we report a simple but novel dianionic phosphate solubilizing group for TEMPO. Owing to its −2 charge, the phosphate group leads to much lower TEMPO permeability through a cation exchange membrane than the more common −1 sulfate group. The new TEMPO‐bearing phosphate is paired with a viologen‐based negolyte to assemble a redox‐flow battery, where it achieves a power density of 110 mW cm −2 and a volumetric capacity of 10.6 Ah l −1 . The phosphate group can be extended to other redox‐active motifs and, therefore, represents a straightforward and effective strategy for the design of water‐soluble materials with low crossover.
Article Details
Authors (5)
Eloi Grignon
Department of Chemistry, University of Toronto, Lash Miller Chemical Laboratories, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
Kimia Hosseini
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
Jônatas Faleiro Berbigier
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
Ailsa K. Edward
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
Dwight S. Seferos
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada