SEPARATOR FOR NONAQUEOUS ELECTROLYTE ELECTRICITY STORAGE DEVICES AND NONAQUEOUS ELECTROLYTE ELECTRICITY STORAGE DEVICE

摘要

Provided is a separator for nonaqueous electrolyte electricity storage devices that includes an improved porous epoxy resin membrane. In the separator for nonaqueous electrolyte electricity storage devices, a ratio I/Io between a peak intensity Io of an absorption peak present at 1240 cm−1 in an infrared absorption spectrum of the porous epoxy resin membrane and a peak intensity I of an absorption peak present at 1240 cm−1 in an infrared absorption spectrum of the porous epoxy resin membrane having been subjected to an acetic anhydride treatment is 1.0 or more and 2.4 or less. The amount of active hydroxyl groups present in the porous epoxy resin membrane can be evaluated by the value of the ratio I/Io.