Polyethylene separator for an energy storage cell

摘要

An improved separator (10) for an energy storage cell is described which is made of a porous polyolefin matrix and contains from about 0.5 to about 30 dry weight percent particulate filler. The particulate filler is a cured, porous rubber material which enhances the electrochemical properties of the separator (10) as compared to conventional polyolefin separators.