Study of the 2,5-Dihydroxy-1,4-Benzoquinone As Redox-Active Material for Aqueous Alkaline Redox Flow Battery

Aqueous organic redox flow batteries (AORFBs) are devices used to store energy. They consist
of organic active species dissolved in an aqueous electrolyte (negolyte and posolyte), which are
held in separate external tanks. The species react reversibly when they are pumped through the
cell electrodes and transfer electrons through an external circuit. AORFBs offer an advantage
over an all-vanadium redox flow battery, the most commercialized inorganic-based RFB,
because their organic redox material is more earth-abundant and has a potentially lower cost.
In this work, we studied the usage of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) as an organic
redox-active molecule in alkaline electrolytes. Despite previous work that has shown that DHBQ
has a high potential as redox-active material for RFB, some problems associated with
membrane cross-over, that generates a loss of capacity, and electrolyte stability need to be
addressed. Thereby, we report our results of a study with different ion-exchange membranes
and our current studies on the stability of the DHBQ in alkaline media.