Bioinspired, high-stability, nonaqueous redox flow battery electrolytes

Abstract

A promising nonaqueous redox flow battery electrolyte has been developed by leveraging natural selection to elucidate stable, redox-active molecules.

Recent progress in organic redox flow batteries: Active materials, electrolytes and membranes

“…(3) Material abundance and low material costs. Many organic active materials can be obtained from the abundant natural resources such as food and plants [55,56] . The abundant resources can dramatically decrease the costs of the RFB system.…”

Repurposing the Industrial Dye Methylene Blue as an Active Component for Redox Flow Batteries

“…Cyclic voltammetry established that as MB is reduced to LMB, no significant decomposition occurs during the experiment. To assess if a molecule is capable of longer‐term energy storage, it is necessary to establish the stability of the redox partners involved beyond the short duration of typical CV experiments, which may obscure decomposition for two reasons: first, a CV experiment is short, typically lasting from seconds to minutes; second, a CV experiment only oxidizes or reduces a small percentage of the active species and thus subsequent chemical decomposition may be slow . As such, a bulk electrolysis experiment wherein the sample was cycled fully between MB and LMB, simulating a 100 % state‐of‐charge cycling, was performed for 50 cycles over seven hours (Figure S3).…”

“…Capacity fades may occur due to one of three mechanisms; i) decomposition of the active species; ii) active species cross‐over iii) active species interaction with the membrane (i. e. adsorption or chemical reaction) . The fact that no new features were observed in the CVs before and after cycling indicate that chemical decomposition is unlikely . To study membrane cross‐over versus membrane adsorption, we assembled an H‐cell where only one side contained MB, separated by the AMI‐7001 membrane.…”

“…The suitability of MB for RFBs was further evaluated by galvanostatic cycling. These experiments compliment potentiostatic charging to characterize the stability of redox species over multiple charge‐discharge cycles ,. Prior to the experiment, MB was reduced using ascorbic acid to obtain LMB.…”

“…In the beginning of the galvanostatic cycling experiment, MB was reduced at the negative electrode and LMB was oxidized at the positive electrode. With this symmetric configuration, potential side effects of additional components are eliminated . With Nafion NE1035 as the membrane separator, an electrolyte solution comprising 2.5 mL of 0.5 mM MB in 50 mM H 2 SO 4 was charged and discharged at 0.05 mA for twelve cycles.…”