A SEPARATOR WITH DEVELOPED SAFETY, PREPARATION METHOD THEREOF, AND ELECTROCHEMICAL DEVICE CONTAINING THE SAME

摘要

PURPOSE: A separator is provided to obtain a stable shut down function when a battery overheats, thereby preventing problems such as a CV section elongating due to the generation of a leak current according to the use of unwoven fabric. CONSTITUTION: A separator comprises: a porous unwoven fabric substrate in which pores are formed between the fabric; and a porous polymer coating layer in which pores are formed, having a melting point lower than the melting point or decomposition point of the unwoven fabric. The porous polymer coating layer is formed from a first polymer having a specific melting point, and a second polymer having a melting point higher than the first polymer. When measuring melting point range according to a DSC curve, the melting initiation temperature and melting termination temperature of the second polymer are respectively higher than the melting initiation temperature and melting termination temperature of the first polymer.