The present invention relates to the separator for batteries wherein the non-woven
cloth comprising fibers mainly composed of polyolefin type resin is provided with
hydrophilic property on the fiber surface at least by sulfuric compound and characterized
as follows:
(a) the ratio of atomic mass of sulfur to atomic mass of carbon (S/C) is
510-3 to 3010-3
(b) the tensile strength is not less than 3 kg/cm2 and the preparation
method of this separator. The present invention also relates to the secondary batteries
using this separator.
