NOVELTY - Membrane (I) comprises a polymer fleece, whose inner and outer portion exhibits a ceramic coating (A) containing at least aluminum oxide, titanium dioxide, zirconium oxide, barium titanate and/or silicon dioxide; where: (A) contains at least two fraction of the above oxides; the first ceramic fraction is obtained from sol; the second fraction particle has an average particle size of 200 nm to 5 mu m; and the amount of the first and second fraction is 0.1-50 parts by weight and 5-99 parts by weight, respectively.    USE - (I) is useful: as a filtration membrane or as an electric separator (which is free of titanium compounds) in lithium batteries, vehicles and filtration apparatus (claimed).    ADVANTAGE - (I) is free of pinhole and wetting defect, exhibits high porosity, ideal pore value, low thickness, light weight, good wetting behavior, improved adhesiveness, liability and good bending property. (I) provides a battery with good battery performance, mechanical stability and high safety (i.e. no melt-down-effect).    DETAILED DESCRIPTION - Membrane (I) comprises a polymer fleece, whose inner and outer portion exhibits a ceramic coating (A) containing at least an aluminum oxide, titanium dioxide, zirconium oxide, barium titanate and/or silicon dioxide; where: (A) contains at least two fraction of the above oxides; the first ceramic fraction is obtained from sol; the second fraction particle has an average particle size of 200 nm to 5 mu m; the first fraction is in the form of a layer on the particles of the second fraction; the amount of the first and second fraction is 0.1-50 parts by weight and 5-99 parts by weight, respectively; (A) further comprises silicon or zirconium containing cross-linker; the silicon of the cross-linker is bonded over oxygen atoms of the oxides of (A); over the organic residue at the surface of the polymer fleece and over at least a carbon chain, a further silicon is bonded; and (A) is pinhole-free. An INDEPENDENT CLAIM is included for the preparation of the membrane comprising applying (A) to the inner and outer portion of the polymer fleece; hardening (A) by uniform heating; subjecting the polymer fleece to plasma treatment, before applying (A); and treating the polymer fleece coated with (A) with UV-radiation; where: (A) before the application is based on a mixture of at least two different adhesive agent, respectively based on an alkylalkoxy silane compound of formula ((R)x-Si(OR)4-x) (I); the adhesive agents are selected such that both the adhesive agent exhibits alkyl residue with at least one reactive group as substituent; the polymer surface subjected to the plasma treatment forms a covalent bond in the presence of UV-radiation.    R = an organic residue; and    x = 1 or 2.