Battery separators

Abstract

The present invention provides a battery separator comprising a nonwoven electrolyte reservoir layer bonded to a nonwoven support layer. The support layer comprises fibers having a mean diameter greater than about 15 microns, and preferably has been calendared to a thickness of less than about 10 mils, with a thickness variability of no more than about 10%. The electrolyte reservoir layer comprises fibers having a mean diameter of about 10 microns or less, and a thickness of less than about 15 mils, and preferably is melt-blown directly onto the support layer. The nonwoven fibers that comprise the electrolyte reservoir layer and the support layer are selected from the group consisting of polyethylene, polypropylene, polymethylpentene, and combinations thereof. The present invention also provides a battery containing such a battery separator, as well as a method of preparing such a battery separator.

Dependencies are inferred from the claim text.