High absorption rate battery separator

摘要

A battery separator of a cellulosic nonwoven substrate coated on at least one surface with a cellulose film and process for making such separator by contacting a nonwoven cellulosic 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 having a degree of polymerization of at least 500, preferably at least 600, to form a coated substrate; washing and drying the coated substrate to provide a battery separator having a absorption rate of at least 6 mm/5 min. and a 30% KOH absorption of at least 200 g/m2.