PE separator is following the rubber separator，glass fiber separator，polyethylene (PVC) separator after the new separator，it has a high porosity，small aperture，small resistance, good toughness, sealing and other advantages, can prevent the edge short circuit, can reduce the active material off, improve the life of the battery.

Because the partition is very thin, reduce the distance between the plates, improve the specific energy of the battery, suitable for low temperature starting. At the same time, PE partition production machinery degree is higher, can be continuous production, and can automatically package, improve labor productivity. Qualified finished PE separator, generally contains about 13% of the oil, the oil evenly distributed on the surface and the interior of PE separator (slightly more on the rib), forming a protective film, the polyethylene in the separator plays a protective role.

When oxidants (such as oxygen) are present, the oil is oxidized first, followed by polyethylene. Therefore, the oil can increase the aging resistance of PE separator to a certain extent. PE partition oxidation (high temperature, oxidant, uv, etc.), the internal polyethylene degradation, molecular chain fracture, molecular weight reduction, physical performance is reduced elongation, ductility loss (brittle), or even fragmentation. Generally used in the international PE partition elongation (MDCMD) and oxidation after the elongation (MDCMD) to measure the oxidation resistance of the partition.