ELECTRODE FOR REDOX-FLOW BATTERIES, REDOX-FLOW BATTERY CELL, AND REDOX-FLOW BATTERY

An electrode for redox flow batteries, the electrode being formed of a carbon fiber aggregate including a plurality of carbon fibers. Each of the carbon fibers has a plurality of pleats formed in the surface thereof. The ratio of L1 to L2, that is, L1/L2, is more than 1, where L1 is the peripheral length of a cross section of the carbon fibers and L2 is the peripheral length of a virtual rectangle circumscribing the cross section of the carbon fibers.