US Patent 10290889 Redox flow battery

Provided is a redox flow battery that allows suppression of generation of precipitate and also has a high energy density. The redox flow battery includes a battery cell including a positive electrode, a negative electrode, and a membrane interposed between the electrodes, the battery being configured to be charged and discharged while a positive electrode electrolyte and a negative electrode electrolyte are supplied to the battery cell, wherein the positive electrode electrolyte contains manganese ions, titanium ions, and reactive metal ions, the negative electrode electrolyte contains at least one species of metal ions selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and the reactive metal ions are at least one selected from vanadium ions, chromium ions, iron ions, cobalt ions, copper ions, molybdenum ions, ruthenium ions, palladium ions, silver ions, tungsten ions, mercury ions, and cerium ions.