These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
A Self-Trapping, Bipolar Viologen Bromide Electrolyte for Aqueous Redox Flow Batteries
preprintrevised on 11.06.2020, 17:41 and posted on 12.06.2020, 08:02 by wenda wu, Jian Luo, Fang Wang, Bing Yuan, Tianbiao Liu
Aqueous organic redox flow batteries (AORFBs) have become increasing attractive for scalable energy storage. However, it remains challenging to develop high voltage, powerful AORFBs because of the lack of catholytes with high redox potential. Herein, we report methyl viologen dibromide ([MV]Br2) as a facile self-trapping, bipolar redox electrolyte material for pH neutral redox flow battery applications. The formation of the [MV](Br3)2 complex was computationally predicted and experimentally confirmed. The low solubility [MV](Br3)2 complex in the catholyte during the battery charge process not only mitigates the crossover of charged tribromide species (Br3-) and addresses the toxicity concern of volatile bromine simultaneously. A 1.53 V bipolar MV/Br AORFB delivered outstanding battery performance at pH neutral conditions, specifically, 100% total capacity retention, 133 mW/cm2 power density, and 60% energy efficiency at 40 mA/cm2.