POLYOLEFIN-BASED MICROPOROUS MEMBRANE, SECONDARY BATTERY INCLUDING THE SAME, AND MANUFACTURING METHOD THEREOF

原文（中国語）

A polyolefin-based microporous membrane, a separator for a secondary battery, and manufacturing method thereof are provided. The polyolefin-based microporous membrane has a puncture strength of 0.3 N/μm or more, a gas permeability of 0.8×10Darcy or more, a porosity of 30.0% or more, and a surface roughness of 2.1 μm or less, the surface roughness being obtained by selecting 5 random points on a front surface and 5 random points on a back surface, each random point having an area of 284 μm wide×220 μm long, measuring a maximum height difference (μm, R) which is a difference between the highest surface height and the lowest surface height in the area of each point, and adding an average value of values measured in each of the 5 points on the front surface and an average value of values measured in each of the 5 points on the back surface.