High porosity separator film with coating and shutdown function

摘要

The invention concerns a biaxially orientated, single- or multi-layered porous film which comprises at least one porous layer and this layer contains at least one propylene polymer and polyethylene; (i) the porosity of the porous film is 30% to 80%; and (ii) the permeability of the porous film is 1000 s (Gurley number); characterized in that (iii) the porous film comprises an inorganic, preferably ceramic coating; and (iv) the coated porous film has a Gurley number of 1500 s; and (v) the coated porous film has a Gurley number of 6000 s when it is heated for 5 minutes to over 140° C. The coated, porous film has dual safety features. Furthermore, the invention also concerns a process for the production of a film of this type as well as its use in high energy or high performance systems, in particular in lithium, lithium ion, lithium-polymer and alkaline-earth batteries.