On the Tunability of Toxicity for Viologen-Derivatives as Anolyte for Neutral Aqueous Organic Redox Flow Batteries

Viologen-derivatives are the most widely used redox organic molecules for neutral pH negative electrolyte of redox flow batteries. However, the long-established toxicity of the herbicide methyl-viologen raises concern for deployment of viologen-derivatives at large scale in flow batteries. Herein, we demonstrate the radically different cytotoxicity and toxicology of a series of viologen-derivatives in in vitro assays using model organisms representative of human and environmental exposure, namely human lung carcinoma epithelial cell line (A549) and the yeast Saccharomyces cerevisiae. The results show that safe viologen derivatives can be molecularly engineered, representing a promising family of negolyte materials for neutral redox flow batteries. Viologen toxicity: The long-established toxicity of the herbicide methyl-viologen raises concern for deployment of viologen-derivatives as anolyte for neutral aqueous organic redox flow batteries (AORFB) at large scale. Here we show that non-toxic viologen derivatives can be molecularly engineered, holding great promise as safe anolytes for AORFB.+image

Automated summary

This study demonstrates the different cytotoxicity and toxicology of a series of viologen derivatives through in vitro assays using model organisms. The results show that safe viologen derivatives can be molecularly engineered, offering a promising choice of negolyte materials for neutral redox flow batteries.