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

Claim 0:
1. An electrolyte membrane for a redox flow battery, comprising a perfluorocarbon polymer having an ion-exchange group, 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% in the following relative dimension by dipping in 2 M aqueous sulfuric acid solution:, <relative dimension by dipping in 2 M aqueous sulfuric acid solution>
an electrolyte membrane for testing having a water content of 1% or less is prepared; the electrolyte membrane for testing is dipped in a 2 M aqueous sulfuric acid solution 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 and a Y direction orthogonal to the X direction are calculated according to the following expression:

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