Patent ID: 8142920

Claim:
A lithium battery, comprising: a membrane which comprises: a polymeric nonwoven comprising a ceramic coating both on and in the polymeric nonwoven; wherein the ceramic coating comprises at least two fractions of oxides selected from the group consisting of Al 2 O 3 , ZrO 2 , TiO 2 , and SiO 2 , a first ceramic fraction obtained from a sol, and a second ceramic fraction comprising particles having an average particle size in the range of from 200 nm to 5 μm, wherein the ceramic coating comprises from 1 to 30 parts by mass of the first ceramic fraction and from 5 to 94 parts by mass of the second ceramic fraction, wherein the first ceramic fraction is present as a layer on the particles of the second ceramic fraction, wherein the second ceramic fraction comprises a silicon network bonded (i) via oxygen atoms to said oxides of the ceramic coating; (ii) via organic radicals to said polymeric nonwoven, and (iii) via at least one carbon chain to a further silicon atom, wherein the membrane is obtained by a process comprising: providing the polymeric nonwoven with the ceramic coating by applying a suspension onto and into said polymeric nonwoven and solidifying the suspension to form the ceramic coating on and in said nonwoven by heating one or more times, wherein said suspension comprises a sol and at least one fraction of oxidic particles selected from the group consisting of oxides of the elements Al, Zr, Ti and Si, and at least two different adhesion promoters which are each based on an alkylalkoxysilane of the general formula I R x —Si(OR) 4-x (I) where x=1 or 2 and R=organic radical, the R radicals being the same or different, wherein both of the adhesion promoters comprise alkyl radicals which at least each comprises a reactive group as a substituent, said reactive group on said alkyl radical of one adhesion promoter said at least one promoter has a reactive group that is capable of reacting under the action of UV light reacting with said reactive group of the other adhesion promoter; and after the applying, exposing the polymeric nonwoven to UV radiation to form a covalent bond between the different adhesion promoters and to form the ceramic coating.