Long life battery separator

摘要

A battery separator of a noncellulosic nonwoven substrate extrusion coated on at least one surface with a cellulose film and process for making such separator by contacting a nonwoven noncellulosic textile substrate with a cellulose or cellulose derivative solution on at least one side of said substrate; converting the solution to a solid cellulose or cellulose derivative, preferably having a degree of polymerization of at least 350, more preferably at least 600, to form a coated substrate; washing and drying the coated substrate to provide a battery separator, preferably having a absorption rate of at least 6 mm/5 min. and a 30% KOH absorption of at least 200 g/m2.