abstract |
The present invention relates to a method for producing a polyolefin-based porous separation membrane, which comprises a plurality of polyolefin-based porous membranes and is capable of exhibiting strength suitable for the separation membrane by limiting the thickness ratio, composition and the like of the porous membrane, The present invention provides a high output battery in which stability and cycle characteristics of a battery are improved or improved through a porous separator capable of securing electrolyte permeability and heat resistance, |