Abstract: Disclosed herein are a variety of systems, compositions, and methods for reversibly storing electrical energy in a symmetric redox flow battery with a unit cell potential equal to or greater than 3 volts. The systems include a conjugated organic molecule, a positive section, and a negative section. The conjugated organic molecule comprises a pair of electron-donating groups and a pair of electron-withdrawing groups, wherein a first electron-donating group of the electron donating groups is one ring position from a first electron-withdrawing group of the electron-withdrawing groups, and wherein a second electron-donating group is one ring position from a second electron-withdrawing group of the electron-withdrawing groups. The positive section includes a first metal electrode in contact with a catholyte comprising a portion of the conjugated organic molecule. The negative section comprises a second metal electrode in contact with an anolyte including an additional portion of the conjugated organic molecule.

Abstract: A redox flow battery may include: a positive half-cell comprising a catholyte; a negative half-cell comprising an anolyte; and an ion permeable membrane, wherein the ion permeable membrane separates the catholyte and the anolyte, and wherein the catholyte, the anolyte, or both comprise a low-transition temperature material comprising: a redox-active phase; and an ionically conducting organic salt.

Abstract: A redox flow battery may include: a positive half-cell comprising a catholyte; a negative half-cell comprising an anolyte; and an ion permeable membrane, wherein the ion permeable membrane separates the catholyte and the anolyte, and wherein the catholyte, the anolyte, or both comprise a low-transition temperature material comprising: a redox-active phase; and an ionically conducting organic salt.