This multilayer, microporous polyolefin membrane has a first microporous layer containing polypropylene.

The charge modified microporous membrane can also be a reinforced microporous membrane, preferably a porous reinforcing web impregnated with a polymeric microporous membrane.

The microporous separator layer may comprise one or more microporous xerogel layers.

The invention relates to a microporous membrane.

Embodiments of the present invention generally relate to microporous membrane, methods for making microporous membrane, and the use of microporous membrane as battery separator film.

The material can be a microporous sheet.

A microporous membrane structure is disclosed that comprises a microporous membrane formed of a synthetic polymer and a substantially continuous porous coating on the membrane.

Its microporous structure gives it a very strong adsorbent power.

The separator is a microporous membrane including a rubber.

The rubber may be impregnated into the microporous membrane.

Some of the micro-wells are covered with a micro-porous membrane.

Microporous polypropylene film of a thickness of not more than 100 μm

The microporous membrane is permeable to a matrix material.

The microporous layer (18) provides a hydrophobic surface (22).

The microporous mould part (4, 5) or the microporous section (6) thereof is pre-heated by supply of warm fluid, such as a heated gas.