Physical Organic Approach to Persistent, Cyclable, Low-Potential Electrolytes for Flow Battery Applications

The deployment of nonaqueous redox
flow batteries for grid-scale
energy storage has been impeded by a lack of electrolytes that undergo
redox events at as low (anolyte) or high (catholyte) potentials as
possible while exhibiting the stability and cycling lifetimes necessary
for a battery device. Herein, we report a new approach to electrolyte
design that uses physical organic tools for the predictive targeting
of electrolytes that possess this combination of properties. We apply
this approach to the identification of a new pyridinium-based anolyte
that undergoes 1e– electrochemical
charge–discharge cycling at low potential (−1.21 V vs
Fc/Fc+) to a 95% state-of-charge without detectable capacity
loss after 200 cycles.