Benzoquinone-Hydroquinone Couple for Flow Battery

Abstract

At present, there is an ongoing search for approaches toward the storage of energy from intermittent renewable sources like wind and solar. Flow batteries have gained attention due to their potential viability for inexpensive storage of large amounts of energy. While the quinone/hydroquinone redox couple is a widely studied redox pair, its application in energy storage has not been widely explored. Because of its high reversibility, low toxicity, and low component costs, we propose the quinone/hydroquinone redox couple as a viable candidate for use in a grid-scale storage device. We have performed single-electrode tests on several quinone/hydroquinone redox couples, achieving current densities exceeding 500 mA/cm 2 , which is acceptable for use in energy applications. We fabricated a full cell using para-benzoquinone at the positive electrode against a commercial fuel cell hydrogen electrode separated by a Nafion membrane. We evaluated its performance in galvanic mode, where it reached current densities as high as 150 mA/cm 2 . The results from these studies indicate that the quinone/hydroquinone redox couple is a promising candidate for use in redox flow batteries.

Recent developments in organic redox flow batteries: A critical review

“…The energy densities listed in Table 3 are based mainly on the energy density of the electrolyte and do not take account of the flow cell and electrolyte piping. Some organic active species, particularly quinones [40,75,121,125], are highly reversible and relatively stable in aqueous electrolytes. The incorporation of these materials enables a reasonable approach to achieving low-cost redox flow batteries with performance characteristics that are comparable to conventional metallic systems.…”

“…This was achieved by creating derivatives of molecules under investigation in the literature, or by proposing new molecules. The chemistries of aqueous organic redox flow batteries are still limited to the groups of quinones [40,75,[120][121][122][123][124][125], quinoxalines [54,126], and several polymer-based [71] chemistries. The reaction mechanisms of these molecules have been studied extensively in the literature.…”

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

“…This pH‐dependence is due to the proton‐coupled electron‐transfer (PCET) involved in the redox chemistry of MB. Active species that invoke PCET redox chemistry have been previously observed in a handful of other molecules, the most notable being quinones ,. This pH tunability can serve as the basis for enhancing cell voltages by shifting the E 1/2 values .…”

“…A unique aspect of RFBs is the spatial separation of the electrodes from the reservoirs serving to decouple energy (stored capacity) and power (energy released per unit time). A moderate library of electrolyte materials including complexes, [28][29][30][31][32][33][34][35][36] organic compounds, [36][37][38][39][40][41] and redox active polymers [42][43][44] has been explored as charge-carriers in RFBs; however, the broad-scale implementation of these devices is hindered by the lack of suitable charge-carriers.…”

“…Active species that invoke PCET redox chemistry have been previously observed in a handful of other molecules, the most notable being quinones. [37,[46][47][48] This pH tunability can serve as the basis for enhancing cell voltages by shifting the E 1/2 values. [49] In this work, we focus on the redox behaviours of MB under acidic conditions.…”