TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Battery: In the battery, in its uncharged state, the rechargeable battery includes a molten salt comprising quinone or quinone derivative A in its reduced form, having the structure of Formula (IB) at the first electrode, and a molten salt comprising hydroquinone or hydroquinone derivative B in its oxidized form, having the structure of Formula (IIB) or Formula (IIIB) at the second electrode, where during the charging process charge flows from the first electrode to the second electrode through the oxidation of the reduced form of quinone or quinone derivative A according to reaction scheme 1b and the reduction of the oxidized form of hydroquinone or hydroquinone derivative B according to reaction scheme 2b or 3b. The hydroquinone or hydroquinone derivative B has the structure of Formula III. The difference in redox potential ( delta ?) between the redox reactions of quinone or quinone derivative A and hydroquinone or hydroquinone derivative B is greater than 0.0 V. The A group of quinone or quinone derivative A is -SO3-, COO-, O-HPO3, -O-PO32 or R-O-SO3-. The hydroquinone or hydroquinone derivative B has any one of the structures represented by formulas (a-c). The molten salts are in the form of ionic liquids having a melting point of 100 degrees C or less. The anion of the molten salt is quinone or quinone derivative A or hydroquinone or hydroquinone derivative B and the cation of the molten salt has any one of the structures represented by formulas (d-h), or a combination. The cation of the molten salt is quinone or quinone derivative A or hydroquinone or hydroquinone derivative B, and the anion of the molten salt is phosphorus hexafluoride (PF6), tetrafluoroborate, bistriflimide, triflate, fluoroalkylsulfonates, nitrate, hexafluorophosphate, carboxylic acids, phosphate, alkylphosphates, dicyanamide, hydrogen sulfate (HSO4-), sulfite (SO3-), thiocyanate or a combination. Moreover, a current of up to 0.5 amps/cm2 of electrode area can be generated from it. Also, a single cell voltage of up to 1.5 volts can be generated from it. The energy storage capacity of the battery is at least 0.01 Amp hour/cm3 of quinone or quinone derivative, or hydroquinone or hydroquinone derivative. The battery of the present invention recharges to at least 99% of its initial redox potential. The battery is charged and mass balanced. The redox reactions of reaction schemes 1a, 2a and 3a proceed at temperatures of 100 degrees C or less. The battery does not comprise any molten metal. The electrodes comprise a platinum electrode, or a platinum mesh. The ion-conducing barrier is a solid polymer electrolyte, where the solid polymer electrolyte is a perfluorinated polymer comprising fixed sulfonate groups, and where the perfluorinated polymer comprising fixed sulfonate groups is protonated. The molten salt further comprises a further ionic liquid. The further ionic liquid comprises the same counter-ion as the quinone or quinone derivative A or hydroquinone or hydroquinone derivative B. The further ionic liquid comprises bis(trifluoromethyl-sulfonyl)imide as an anion. The molten salt consists essentially of the quinone or quinone derivative A, or the hydroquinone or hydroquinone derivative B, and an anionic or cationic counter-ion. EXAMPLE - No suitable example given.