A coating method for the preparation of a porous separator comprising multiple layers wherein each layer comprises both glass particles and ceramic particles, wherein the method comprises the steps of - providing a mixture of an organic polymeric material, of both glass particles and ceramic particles and at least two solvents, wherein the glass particles and the ceramic particles comprise 5-95% of the mixture, wherein the organic polymeric material comprises 5-95% of the mixture and is selected from the group comprising poly(vinylidene fluoride)-hexafluoropropene (PVDF-HFP), polyvinylidene fluoride (PVDF), PTFE, polymethyl methacrylate (PMMA), polypropylene, polyacrylic acid, polyvinylpyrrolidone, water based PVDF, acrylate, polyacrylate, styrene butadiene rubber, natural and synthetic rubbers, latex, OPPANOL®, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and mixtures thereof, wherein the ceramic particles are made of a material selected from the group comprising lithium aluminium titanium phosphate Li x Al y Ti z (PO 4) 3 where 1 ≤ x ≤ 2, 0 ≤ y ≤ 1 and 1 ≤ z ≤ 2, nano-sized alumina (Al 2 O 3), ZrO 2, SiC, LiAlO 2, SnO 2 or BaTiO 3, wherein the solvent is selected from the group comprising tetrahydrofuran, acetone, ethanol, acetic acid, dimethy lacetamide (DMAC), dimethyl sulfoxide (DMSO), hexamethyl phosphoramide (HMPA), N-methylpyrrolidone, triethyl phosphate, trimethyl phosphate, tetramethyl urea, butanone, propylene carbonate, butanol water, silanole, silandiole, ethylene glycol monohexyl ether, N,N-dimethyl ethanolamine, isopropyl alcohol, toluene, normal butyl alcohol, maleic anhydride, xylene, and mixtures thereof, and - preparing a multilayer by phase inversion. - providing a mixture of an organic polymeric material, of both glass particles and ceramic particles and at least two solvents, wherein the glass particles and the ceramic particles comprise 5-95% of the mixture, wherein the organic polymeric material comprises 5-95% of the mixture and is selected from the group comprising poly(vinylidene fluoride)-hexafluoropropene (PVDF-HFP), polyvinylidene fluoride (PVDF), PTFE, polymethyl methacrylate (PMMA), polypropylene, polyacrylic acid, polyvinylpyrrolidone, water based PVDF, acrylate, polyacrylate, styrene butadiene rubber, natural and synthetic rubbers, latex, OPPANOL®, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and mixtures thereof, wherein the ceramic particles are made of a material selected from the group comprising lithium aluminium titanium phosphate Li x Al y Ti z (PO 4) 3 where 1 ≤ x ≤ 2, 0 ≤ y ≤ 1 and 1 ≤ z ≤ 2, nano-sized alumina (Al 2 O 3), ZrO 2, SiC, LiAlO 2, SnO 2 or BaTiO 3, wherein the solvent is selected from the group comprising tetrahydrofuran, acetone, ethanol, acetic acid, dimethy lacetamide (DMAC), dimethyl sulfoxide (DMSO), hexamethyl phosphoramide (HMPA), N-methylpyrrolidone, triethyl phosphate, trimethyl phosphate, tetramethyl urea, butanone, propylene carbonate, butanol water, silanole, silandiole, ethylene glycol monohexyl ether, N,N-dimethyl ethanolamine, isopropyl alcohol, toluene, normal butyl alcohol, maleic anhydride, xylene, and mixtures thereof, and - preparing a multilayer by phase inversion.