Separator for secondary battery comprising dual porous coating layers of inorganic particles with different average particle diameter secondary battery comprising the same and method for preparing the separator

摘要

The present invention relates to a separator for a secondary battery, a secondary battery comprising the same, and a method for producing the separator, which comprises a porous porous coating layer of inorganic particles having different average particle diameters. According to one embodiment of the present invention, there is provided a separation membrane for a secondary battery comprising a porous substrate, a first porous coating layer and a second porous coating layer. According to another embodiment of the present invention, there is provided a method of manufacturing a separator for a secondary battery, comprising the steps of forming a first slurry, forming a second slurry, forming a first porous coating layer, and forming a second porous coating layer . According to an aspect of the present invention, the heat shrinkage of the separator is reduced, and the output of the cell including the separator is improved.