SEPARATOR FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a separator for a lithium ion secondary battery, capable of achieving a lithium ion secondary battery with excellent cycle characteristics, while favorably maintaining the shape of a separator even when a separator capable of achieving increased battery capacity and including a nonwoven fabric is used.SOLUTION: A separator for a lithium ion secondary battery comprises: a nonwoven fabric containing a polyester resin; and an inorganic thin film laminated on the nonwoven fabric and having a thickness of 60 nm or more.