SEPARATOR, MANUFACTURING METHOD THEREOF, AND LITHIUM ION SECONDARY CELL

摘要

The purpose of the present invention is to provide a separator which maintains high rate characteristics and which can suppress short circuits. The means for solving this problem is a separator which includes a substrate having an inner surface and an outer surface, and inorganic particles present on the outer surface and the inner surface of the substrate, wherein the porosity of the substrate is 55% or greater, and the average flow pore diameter of the substrate is 30μm or less, the average particle diameter of the inorganic particles is 1.0-4.0μm, and wherein particles of diameter 1.0μm or less make up 40 vol% or less of the inorganic particles, and particles of diameter 2.0μm or greater make up 30-75 vol% thereof.