Microporous membrane battery separator for silver zinc batteries

Abstract

A separator membrane for use in silver-zinc batteries is produced by extruding a blend of two fillers with the same chemical formula but different particle size. A polyolefine polymer and a plasticizer are blended and extruded to form a thin sheet of 1 to 10 mil thickness. The plasticizer is then extracted to leave submicron voids in the membrane. Plasticizers are added as processing aids, and can be either soluble or insoluble in water, and include petroleum oils, lubricating oils, fuel oils, and natural oils such as tall oils and linseed oils. The oil are then extracted from the membrane by conventional procedures such as single stage extraction using a suitable solvent. Commercially available wetting agents known to the art such as dodecylphenoxy polyethoxy ethanol and isooctyl phenyl polyethoxy ethanol are coated onto the sheet to improve wettability. The sheet is then dried, and boiled in distilled water for one minute or more, before being finally dried.

Dependencies are inferred from the claim text.