POROUS MEMBRANE HAVING SINGLE LAYER STRUCTURE, BATTERY SEPARATOR MADE THEREOF, PREPARATIONS THEREOF AND BATTERY EQUIPPED WITH SAME BATTERY SEPARATOR

摘要

A porous membrane of a single layer structure formed from a first polymer having a melting point of at least 130.degree.C and a second polymer having a melting point of up to 120.degree.C, wherein the walls of the pores of the membrane have an amount of second polymer insufficient to block the permeability of the pores under normal operating temperature conditions yet sufficient to do so when the membrane reaches a temperature equal to or greater than the second polymer's melting point.