SEPARATOR FOR NONAQUEOUS ELECTROLYTE BATTERIES, AND NONAQUEOUS ELECTROLYTE BATTERY

摘要

A separator for nonaqueous electrolyte batteries, which comprises a multilayer porous membrane that is provided with: a polyolefin microporous membrane; and a porous layer that contains an inorganic filler and is provided on at least one surface of the polyolefin microporous membrane. This separator for nonaqueous electrolyte batteries is characterized in that with respect to pores having an area of 0.01 μm2 or more in a cross-section of the porous layer of the multilayer porous membrane, not less than 30% of the pores have an angle &thetas; satisfying 60° ≤&thetas;≤ 120°, said angle &thetas; being the angle between the major axis of each pore and an axis that is parallel to the interface between the microporous membrane and the porous layer.