REDOX FLOW BATTERY

A redox flow battery includes a cell, an electrolyte tank configured to store an electrolyte supplied to the cell, and a circulation mechanism disposed between the cell and the electrolyte tank and configured to circulate the electrolyte. The circulation mechanism includes a suction pipe configured to suck up the electrolyte from an open end thereof in the electrolyte to above an in-tank liquid level of the electrolyte in the electrolyte tank, a circulation pump disposed at an upper end of the suction pipe, an extrusion pipe running from a discharge port of the circulation pump to the cell, and a return pipe running from the cell to the electrolyte tank. HL/H0is greater than or equal to 0.4 and HSis less than or equal to HL, where H0is a height from an inner bottom surface of the electrolyte tank to the in-tank liquid level, HLis a length from the open end of the suction pipe to the in-tank liquid level, and HSis a height from the in-tank liquid level to a center of a suction port of the circulation pump.