Complex fibrous separator having shutdown function and secondary battery using the same

摘要

The present invention relates to a complex porous separator which improves the ion mobility property of the complex porous separator by making the porosity of a porous member used as a support unit equal or similar to the porosity of a porous polymer web layer, and has a shutdown function by a porous member, and a secondary battery using the same. The complex porous separator according to the present invention includes a porous member which functions as a support unit and has a first melting point and a first porosity; a first porous polymer web layer which is stacked on one side of the porous member and functions as a bonding layer when it touches an opposite electrode; and a second porous polymer web layer which is stacked on the other side of the porous member and is made of nanofiber of heat-resistant polymer. The first and the second porous polymer web layers have a higher melt point compared to the first melt point of each porous member and have porosity equal or similar to the first porosity.