| 摘要 |
PURPOSE:To obtain a diaphragm for an iron/chrome system redox flow battery having little iron ion transmission and low film resistance in a working system. CONSTITUTION:When using a diaphragm 6 having a negative ion exchange thin layer and a positive ion exchange layer and AC resistance in hydrochloric acid 0.03-2OMEGA.cm<2> while consisting of at least two layers for a redox flow battery 3, transmission of iron ions to the side of a negative pole 4 can be sharply reduced by composing its negative ion exchange layer toward a positive pole. An exchange radical of the positive ion exchange layer consists of a sulfon acid radical while its resistance is desirably 0.02-1.5OMEGA.cm<2> and further 60-99.5% of the total resistance. Further, as the exchange radical of its negative ion exchange thin layer, it is desirable that either of an amin radical of the first class, second class, third class and an ammonium radical of the fourth class or a mixture thereof may exist, while the amount of existance thereof may be in the range of 0.5X10<-4>meq/cm<2>-2X10<-3>meq/cm<2>, more desirably 1X10<-4>meq/cm<2>-1X10<-3> meq/cm<2>. |
