Abstract: Disclosed is a battery separator, comprising two fiber regions comprising glass fibers, and a middle fiber region disposed between them comprising larger average diameter fibers and specified amounts of silica, or fine fibers, or both; and processes for making the separator. Also disclosed is a battery separator, comprising a fiber region and either one or two silica-containing region(s) adjacent thereto, each of the regions containing a specified amount of silica; and processes for making the separator. Such separators are useful, e.g., in lead-acid batteries.

Abstract: Disclosed is a battery separator, comprising two fiber regions comprising glass fibers, and a middle fiber region disposed between them comprising larger average diameter fibers and specified amounts of silica, or fine fibers, or both; and processes for making the separator. Also disclosed is a battery separator, comprising a fiber region and either one or two silica-containing region(s) adjacent thereto, each of the regions containing a specified amount of silica; and processes for making the separator. Such separators are useful, e.g., in lead-acid batteries.

Abstract: Disclosed is a battery separator, comprising a coarse fiber region comprising fibers, such as glass fibers, having an average diameter of greater than or equal to 2 ?m; a first fine fiber region comprising glass fibers having an average diameter of less than or equal to 2 ?m, and a second fine fiber region comprising glass fibers having an average diameter of less than or equal to 2 ?m, wherein the coarse fiber region is disposed between the first fine fiber region and the second fine fiber region, and wherein the thickness of the coarse fiber region constitutes 1-49% of the sum of the thicknesses of the coarse fiber region, the first fine fiber region and the second fine fiber region. Such a separator is useful, e.g., in a lead-acid battery, where during filling of the battery with acid, the separator enhances the diffusion of acid toward the interior region.