Cell frame, cell stack, and redox flow battery

A cell frame comprising a bipolar plate disposed between a positive electrode and a negative electrode of a redox flow battery, and a frame member that supports the bipolar plate at an outer periphery of the bipolar plate,

• wherein an introduction channel and a discharge channel, which is independent of and not connected to the introduction channel, are provided in each of a surface of the cell frame that faces the positive electrode and a surface of the cell frame that faces the negative electrode, the introduction channel introducing an electrolyte to a corresponding one of the electrodes, the discharge channel discharging the electrolyte from the corresponding one of the electrodes,
• wherein the introduction channel includes an introduction rectifying groove and a plurality of introduction branch grooves that are connected to the introduction rectifying groove and spaced from each other,
• wherein the discharge channel includes a discharge rectifying groove and a plurality of discharge branch grooves that are connected to the discharge rectifying groove and spaced from each other,
• wherein the introduction branch grooves extend toward the discharge rectifying groove and the discharge branch grooves extend toward the introduction rectifying groove, and
• wherein separation distances X between the introduction rectifying groove and the discharge branch grooves and separation distances Y between the discharge rectifying groove and the introduction branch grooves are in a range from 1 mm to 30 mm.