Patent ID: 11876267
Assignee: ASAHI KASEL KABUSHIKI KAISHA
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  C  Y | IPC H

Claim 15:
16. A method for producing an electrolyte membrane for a redox flow battery, comprising:
drawing a raw material membrane containing a perfluorocarbon polymer having an ion-exchange group under heating, wherein
the perfluorocarbon polymer has equivalent weight EW of the ion-exchange group of 600 g/eq or more and 2000 g/eq or less,
a craze area ratio of the electrolyte membrane is 1.5% or less, and
a relative dimension of the electrolyte membrane in at least one of a X direction and a Y direction is 80% or more and less than 100%, and a relative dimension thereof in a Z direction is 115% or more, in the following relative dimension by dipping in distilled water:, <relative dimension by dipping in distilled water>
an electrolyte membrane for testing having a water content of 1% or less is prepared; the electrolyte membrane for testing is dipped in distilled water at 25° C. for 30 minutes; and ratios of change in dimension in a X direction on a surface of the electrolyte membrane for testing, a Y direction orthogonal to the X direction, and a Z direction orthogonal to the X direction and the Y direction are calculated:

Relative dimension (%)={(Dimension in a specific direction after the dipping)/(Dimension in the specific direction before the dipping)}×100.