Provided is a multilayer porous separator film comprising at least one oriented layer, said one oriented layer comprising a heat, solvent, and degradation resistant matrix polymer; an open and interconnecting pore structure; and superior ionic conductivity. The film is made by a dry and/or wet method, with its multilayer structure constructed by coextrusion, lamination, and coating. The film of this disclosure finds a wide range of applications as a permselective medium for use in energy harvesting and storage, filtration, separation and purification of gases and fluids, CO2 and volatile capture, electronics, devices, structural supports, packaging, labeling, printing, clothing, drug delivery systems, bioreactor, and the like. The film is preferably used as a separator of lithium-ion, lithium-sulfur, lithium-air, metal-air, and nonaqueous electrolyte batteries.