Non-aqueous electrolyte battery separator and a non-aqueous electrolyte battery

PROBLEM TO BE SOLVED: To provide a separator capable of constituting a nonaqueous electrolyte battery excellent in safety when abnormal heat is generated; and to provide a nonaqueous electrolyte battery having the separator. SOLUTION: The separator for the nonaqueous electrolyte battery has a resin porous membrane containing thermoplastic resin as the main component and in which thermal shrinkage at 150°C is 10% or more and a heat resistant porous layer formed on the surface of the resin porous membrane and containing 70 or more vol.% heat resistant fine particles. The nonaqueous electrolyte battery uses the separator. In the separator for the nonaqueous electrolyte battery, the ratio A/B of the thickness A (μm) of the resin porous membrane to the thickness B (μm) of the heat resistant porous layer is preferably 1-5. COPYRIGHT: (C)2008,JPO&INPIT