We report a high performance aqueous redox flow battery employing inexpensive, stable and non-toxic organic materials in alkaline electrolyte. An anthraquinone in the negative electrolyte paired with ferro/ferricyanide in the positive electrolyte results in an open circuit voltage of 1.2 V, a peak galvanic power density exceeding 0.7 W/cm², and a membrane crossover rate three orders of magnitude lower than with inorganic redox couples [1]. Additionally, a redox-active non-quinone organic negative electrolyte, prepared from a single-step coupling reaction of inexpensive bulk commodity chemicals, exhibits an open-circuit voltage exceeding 1.15 V against ferro/ferricyanide. This molecule has a room temperature solubility of 4 M electrons, yielding a charge density of organic negative electrolyte of 108 Ah/L.

[1] K. Lin, Q. Chen, M.R. Gerhardt, L. Tong, S.B. Kim, L. Eisenach, A.W. Valle, D. Hardee, R.G. Gordon, M.J. Aziz and M.P. Marshak, "Alkaline Quinone Flow Battery", Science 349, 1529 (2015)