Ruben Rubio-Presa, Lara Lubian, Mario Borlaf, Edgar Ventosa, Roberto Sanz
In practical scenarios, viologen-derivatives face an accelerated degradation in the unavoidable presence of traces of oxygen in large-scale redox flow batteries. Herein, we confirm the primary degradation mechanism and propose a straightforward, cheap, and fast method to evaluate the stability of viologen-derivatives toward this degradation. A new viologen-derivative is designed and synthesized to illustrate how molecular engineering can be used to improve stability.