SEPARATION MEMBRANE FOR REDOX FLOW SECONDARY BATTERIES, AND REDOX FLOW SECONDARY BATTERY USING SAME

摘要

This redox flow secondary battery is provided with an electrolytic cell that comprises a positive electrode cell chamber, a negative electrode cell chamber and a separation membrane that separates the positive electrode cell chamber and the negative electrode cell chamber from each other. In addition, the redox flow secondary battery is configured as follows: the separation membrane has a microporous membrane and an ion exchange resin layer that is in contact with the microporous membrane; the air resistance of the separation membrane per a thickness of 200 μm is 10,000 seconds/100 cc or more; the microporous membrane contains a polyolefin resin or a vinylidene fluoride resin and an inorganic filler; and at least a surface of the microporous membrane, said surface being in contact with the ion exchange resin layer, has a smoothness of 16,000 seconds or less.