Abstract
Aqueous redox flow batteries using low-cost organic and inorganic active materials have received growing interest for sustainable energy storage. In this study, a low-cost, high redox potential (1.08 V vs. NHE) and high capacity ammonium bromide (NH4Br, 214.4 A h L-1) catholyte was coupled with an organic viologen anolyte to demonstrate 1.51 V high voltage (SPr)2V/Br- aqueous redox flow batteries under pH neutral conditions for the first time. Benefitting from the high water solubility of both the NH4Br catholyte and (SPr)2V anolyte, the newly designed (SPr)2V/Br- organic flow battery was operated at up to 1.5 M and an energy density of up to 30.4 W h L-1. Using multiwall carbon nanotubes as an electrochemical additive for the Br3-/Br- redox couple, the highly energy dense (SPr)2V/Br- flow battery manifested outstanding current performance, up to 78% energy efficiency at 40 mA cm-2 current density and 227 mW cm-2 power density, the highest power density known for pH neutral organic flow batteries.
| Original language | English |
|---|---|
| Pages (from-to) | 9130-9136 |
| Number of pages | 7 |
| Journal | Journal of Materials Chemistry A |
| Volume | 7 |
| Issue number | 15 |
| DOIs | |
| State | Published - 2019 |
| Externally published | Yes |
Funding
We acknowledge the nancial support for this research from the National Science Foundation Career Award (grant no. 1847674), faculty startup funds from Utah State University and the Utah Science Technology and Research initiative (USTAR) UTAG award. C. D. is grateful for the USU Presidential Doctoral Research Fellowship provided by USU. B. H. is grateful for the China CSC Abroad Studying Fellowship and the Utah Energy Triangle Student Award provided by the Office of Energy of the Utah State government to support his graduate program. M. H. is grateful for the China CSC Abroad Studying Fellowship provided to support her graduate program.