SEPARATOR FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, AND BATTERY

摘要

PROBLEM TO BE SOLVED: To improve high-temperature storage characteristics of a battery in which a separator made of glass fibers is used, thereby enhancing the high-temperature storage characteristics to the degree similar to those of batteries in which a generally used separator material made of a resin is used.SOLUTION: In a separator for a nonaqueous electrolyte secondary battery, MgO and/or ZrOis added to a separator comprising glass fibers, as an additive. The additive is added so that a product of a BET specific surface area (m/g) and an addition weight ratio (wt%) relative to the whole glass fibers is 300 [(m/g) (wt%)] or more.