| abstract |
A polyolefin porous membrane disclosed. The membrane includes a plurality of protrusions of polyolefin having a size (W) of 5 μm≦W≦50 μm and a height (H) of 0.5 μm≦H. The protrusions are disposed on one side of the polyolefin porous membrane with a density of at least 3/cm 2 and at most 200/cm 2 , and the polyolefin porous membrane has a thickness of at most 20 μm. A battery separator including the membrane is also disclosed. |