ELECTROLYTE MEMBRANE FOR REDOX FLOW BATTERIES, REDOX FLOW BATTERY, AND METHOD FOR PRODUCING ELECTROLYTE MEMBRANE

摘要

The present invention provides an electrolyte membrane for redox flow batteries, which contains a perfluorocarbon polymer having an ion exchange group, and which is configured such that: the perfluorocarbon polymer has an equivalent mass EW of the ion exchange group of from 600 g/eq to 2,000 g/eq (inclusive); the craze area ratio in the electrolyte membrane is 1.5% or less; and at least one of the dimensional change rate in the X direction and the dimensional change rate in the Y direction among the dimensional change rates of the electrolyte membrane by means of the immersion in a 2M sulfuric acid solution described below is 80% or more but less than 100%.