SEPARATOR BASE MATERIAL FOR LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a separator base material for a lithium ion secondary battery having high air permeability and low resistance while having high strength.SOLUTION: Disclosed is a separator base material for a lithium ion secondary battery made of nonwoven fabric obtained from wet papermaking. This separator base material for the lithium ion secondary battery is processed passing through between a heated metal roll and a vinylidene fluoride rubber roll whose hardness measured by a type A durometer specified in JIS K6253 is 65 to 75.