Battery cell and redox flow battery

A battery cell comprising:

• a cell unit in which a membrane is sandwiched between a positive electrode and a negative electrode and the electrodes are sandwiched between a pair of cell frames,
• the cell frames each including a frame body that has a penetrating window and a bipolar plate that contacts the electrode by filling the penetrating window,
• the frame body including a liquid supplying manifold that penetrates through the frame body in a thickness direction thereof to serve as a supply channel of an electrolyte, a liquid discharging manifold that serves as a discharge channel of the electrolyte, an inlet slit through which the electrolyte is introduced from the liquid supplying manifold to the electrode, and an outlet slit through which the electrolyte is discharged from the electrode to the liquid discharging manifold,
• wherein the frame body includes an inner peripheral recessed portion formed by reducing a thickness of a peripheral portion that surrounds an entire perimeter of the penetrating window so that the peripheral portion has a smaller thickness than other portions of the frame body,
• the bipolar plate includes an outer peripheral engaging portion that engages with the inner peripheral recessed portion, the outer peripheral engaging portion being a portion having a particular width and extending throughout an entire outer periphery of the bipolar plate, and
• the battery cell includes a disrupting structure that disrupts a leak channel that serves as an escape route for the electrolyte, the leak channel causing the inlet slit and the outlet slit to be in communication with each other and being formed between an outer periphery of the inner peripheral recessed portion and an outer periphery of the outer peripheral engaging portion when the cell frames are viewed from front,
• wherein, when the cell frames are viewed in plan, a portion of an outer rim portion of the bipolar plate protrudes toward the frame body and this protruding portion disrupts the leak channel.