FLUORENONE/FLUORENOL DERIVATIVES FOR AQUEOUS REDOX FLOW BATTERIES

Aqueous electrolytes comprising fluorenone/fluorenol derivatives are disclosed. The electrolyte may be an anolyte for an aqueous redox flow battery. In some embodiments, the compound, or salt thereof, has a structure according to any one of formulas I-III where Q-Qindependently are CH, C(R) or N, wherein 0, 1, or 2 of Q-Qare N; Q-Qindependently are CH, C(R), or N, wherein 0, 1, or 2 of Q-Qare N; Y is C═O or C(H)OH; Rand Rindependently are an electron withdrawing group; n is an integer >1; and x and y independently are 0, 1, 2, 3, or 4, where at least one of x and y is not 0.